Lela R. Bachrach MD, MS

• Assistant Clinical Professor, Joint Medical Program

https://publichealth.berkeley.edu/people/lela-bachrach/

Afferents to the flocculus of the cerebellum in the rhesus macaque as revealed by retrograde transport of horseradish peroxidase skin care qvc cleocin gel 20 gm purchase. Olfactory impairments in patients with unilateral cerebellar lesions are selective to inputs from the contralesional nostril skin care unlimited discount cleocin gel 20 gm without a prescription. Aprendizaje motor y receptores a canabinoidesen la corteza del cerebelo eNeurobiologia 1:280610 skin care equipment suppliers purchase 20 gm cleocin gel with visa. Fos expression at the cerebellum following non-contact arousal and mating behavior in male rats acne vs pimples buy generic cleocin gel 20 gm line. Changes in brain activation associated with reward processing in smokers and nonsmokers acne cyst removal order cleocin gel 20 gm without a prescription. Distribution of gonadal steroid receptor-containing neurons in the preoptic-periaqueductal gray-brainstem pathway: A potential circuit for the initiation of male sexual behavior. Brain activation in response to visually evoked sexual arousal in male-to-female transsexuals: 3. Organization of visual mossy fiber projections and zebrin expression in the pigeon vestibulo cerebellum. Copulatory behavior and reflexive penile erection in rats after section of the pudendal and genitofemoral nerves. Penile reflexes in intact rats following anesthetization of the penis and ejaculation. Brain processing of audiovisual sexual stimuli inducing penile erection: a positron emission tomography study. Expression and activity of 3b-hydroxysteroid dehydrogenase/D5-D4-isomerase in the rat Purkinje neuron during neonatal life. Some researchers have studied this topic from a primarily behavioral or comparative angle or from an evolutionary perspective. Carlos Beyer, 113 114 Behavioral Neuroendocrinology throughout his brilliant career, integrated neuroendocrine evidence to elucidate the physiological basis of female sexual behavior. He used this approach as a model to explore the cellular and molecular mechanisms by which various hormones, for example, those produced in the ovary (estradiol [E2] and progesterone [P]), neuropeptides, prostaglandins, and other chemical messengers, exert their effects on different brain areas involved in the regulation of specific and physiologically relevant behavior. Beyer proposed a model in which some agents, due to their lipophobicity, do not penetrate into the cell, but exert their effects on receptors located in the cell membrane. Here they would interact with molecules that, in turn, activate intracellular receptors, a phenomenon known as cross-talk, that occurs in a variety of cells including neurons and glial cells, ultimately leading to female sexual behavior. These results have contributed to the understanding of the cellular mechanisms involved in the regulation of female sexual behavior in rats and represent a significant aspect of Dr. In many mammals, receptivity involves the adoption of the lordosis posture, which facilitates penile insertion and ejaculation. In rats, lordosis comprises an arching of the back and elevation of the pelvis that is frequently accompanied by tail deviation. Another behavioral aspect of estrus is proceptivity, the repertoire of female behavior directed toward the male to initiate, establish, and maintain sexual interaction. These behavior patterns include a zigzag locomotion termed "darting" and a presentation posture that may be accompanied by ear-wiggling produced by rapid head shaking (for review, see Pfaff and Sakuma 1980). Estrous behavior (lordosis and proceptivity) is induced by the combined effects of E2 and P; gonadectomy performed in rats and hamsters shortly before the preovulatory P peak interferes with the subsequent expression of lordosis, whereas this response is consistently displayed when animals are ovariectomized (ovx) after the preovulatory P peak (Ciaccio and Lisk 1971; Powers 1970). P only facilitates lordosis behavior if females have been primed with E2 (12­18 hours in rats and guinea pigs). Several species of rodents respond to treatment with E2-only under some conditions. For example, Beyer and colleagues reported that estrogens activate lordosis in ovx rats, with 17b­E2 being the most potent estrogen, followed in decreasing order by estrone and estriol (Beyer et al. In several female mammals, P also exerts an inhibitory effect on sexual behavior; this effect is observed during the formation of the corpus luteum after ovulation occurs, or during pregnancy. This may serve to terminate the period of behavioral estrus and to prevent mating when females are pregnant. In addition, P depresses Progestin Mechanism in Female Sexual Behavior 115 estrous behavior in ovx rats or prevents its induction by E2 when administered concurrently with, or prior to , estrogen, a phenomenon termed concurrent inhibition (Powers and Moreines 1976). After an initial period of behavioral facilitation, P also induces sexual inhibition; if a second injection of P is administered 24 hours after the first, it fails to induce lordosis in the estrogen-primed rodents. This is referred to as sequential inhibition (Feder and Marrone 1977; Morin 1977; González-Mariscal et al. Some coactivators possess intrinsic enzyme activity for acetylation (histone acetyltransferase activity) or methylation of core histones. For a more detailed view of neurotransmitter­receptor mediated effects of neurosteroids, see Paul and Purdy (1992). Protein phosphorylation is the major mechanism through which a variety of hormones regulate intracellular events in mammalian cells (Nestler and Greengard 1994). Beyer, Canchola, and Larsson were the first to explore the role of this intracellular signaling pathway in the display of estrous behavior of ovx, E2-primed rats. From these early results they proposed a unitary model to explain the facilitation of lordosis by P and other hormones with different chemical structures in estrogen-primed rats. This extension of the model accommodates findings, summarized below, that kinases activated by the agents that induce lordosis. However, it is important to note that diverse agents that induce lordosis may act through different protein kinase systems. The hypothalamic content of this messenger doubles between the afternoon and evening of proestrous, when the surge and the period of behavioral receptivity occur (Calka 2006). Icv infusion of this inhibitor decreased lordosis behavior in E2 + P-primed female rats. Lordosis behavior was suppressed at 2 hours but returned to control values by 4 hours. Humoral stimuli originating in the periphery can modulate estrous behavior, and leptin has been reported to influence estrous behavior in rodents (Wade et al. The possibility of a link between leptin and reproduction became evident when it was determined that a homozygous mutation in the leptin (ob) gene was responsible for the obesity syndrome and impaired reproductive function in genetically obese (ob/ob) mice (Zhang et al. Intracerebral administration of leptin failed to augment the lordosis response induced by E2 and P, and inhibited proceptivity in Zucker rats (Fox and Olster 2000). These results suggest that leptin has complex effects on the sexual behavior of rodents. In an initial experiment, we found that various dosages of leptin, infused icv, significantly facilitated lordosis behavior in ovx, E2-primed rats. As described above, many of these agents activate intracellular signaling mechanisms through G protein linked membrane receptors, inducing the formation of second messengers and the facilitation of lordosis behavior in rodents (González-Flores et al. This kinase is present in essentially all eukaryotic cells, where its activation is regulated by diverse growth factors, cytokines, adhesion molecules, and antigen receptors critical for generating an appropriate cellular response to external stimuli (Brown and Cooper 1996; Thomas and Brugge 1997). It is at the heart of a molecular-signaling network that governs the growth, proliferation, differentiation and survival of many, if not all, cell types. The same animals received a second injection of P 24 hours later and were tested again for lordosis. Females showed high levels of lordosis in this test, indicating that sequential inhibition was blocked (González-Flores et al. This hypothesis was confirmed by the observation that a proteasome inhibitor blocked sequential inhibition induced by P (González-Flores et al. Stimulation of these kinases may also activate Src kinase through several mechanisms. The phosphorylation of this amino acid is targeted for degradation by the 26S proteasome. Beyer was to provide evidence that the stimulation of female sexual behavior in rats involved a nongenomic mechanism that could be triggered by a variety of steroidal and nonsteroidal agents. The role of progestin receptors and the mitogen-activated protein kinase pathway in delta opioid receptor facilitation of female reproductive behaviors. A model for explaining estrogen progesterone interactions in induction of lordosis behavior. Effect of diverse estrogen on estrous behavior and genital tract development in ovariectomized rats. Neuroendocrine regulation of estrous behavior in the rabbit: similarities and differences with the rat. Nonligand activation of estrous behavior in rodents: cross-talk at the progesterone receptor. Cytoplasmic progestin-receptors in guinea pig brain: characteristics and relationship to the induction of sexual behavior. Feminine sexual behavior: Cellular integration of hormonal and afferent information in the rodent forebrain. Feminine sexual behavior from neuroendocrine and molecular neurobiological perspectives. The role of extranuclear signaling actions of progesterone receptor in mediating progesterone regulation of gene expression and the cell cycle. The role and mechanism of progesterone receptor activation of extra-nuclear signaling pathways in regulating gene transcription and cell cycle progression. Immunocytochemical detection of progesterone receptor in the female rabbit forebrain: distribution and regulation by oestradiol and progesterone. Progesterone receptor interacting coregulatory proteins and cross talk with cell signaling pathways. The role of insulin-like growth factor-I and growth factor-associated signal transduction pathways in estradiol and progesterone facilitation of female reproductive behaviors. Regulation of estrogen-stimulated lordosis behavior and hypothalamic progestin receptor induction by antiestrogens in female rats. Progesterone: its role in the central nervous system as a facilitator and inhibitor of sexual behavior and gonadotropin release. Effects of intracerebroventricular leptin administration on feeding and sexual behaviors in lean and obese female Zucker rats. The nitric oxide pathway participates in lordosis behavior induced by central administration of leptin. Lordosis facilitation by leptin in ovariectomized, estrogen-primed rats requires simultaneous or sequential activation of several protein kinase pathways. In situ estradiol and progestin (R5020) localization in the vascularly separated and isolated hypothalamus of the rhesus monkey. Facilitation of estrous behavior by vaginal cervical stimulation in female rats involves alpha1-adrenergic receptor activation of the nitric oxide pathway. A role for Src kinase in progestin facilitation of estrous behavior in estradiol-primed female rats. The 26S proteasome participates in the sequential inhibition of estrous behavior induced by progesterone in rats. Regulation of lordosis by cyclic 3,5-guanosine monophosphate, progesterone, and its 5alphareduced metabolites involves mitogen-activated protein kinase. Differential effect of kinase A and C blockers on lordosis facilitation by progesterone and its metabolites in ovariectomized estrogen-primed rats. Progesterone receptor isoforms differentially regulate the expression of tryptophan and tyrosine hydroxylase and glutamic acid decarboxylase in the rat hypothalamus. Changes in progesterone receptor isoforms content in the rat brain during the oestrous cycle and after oestradiol and progesterone treatments. Role of progesterone receptor isoforms in female sexual behavior induced by progestins in rats. Progesterone signaling in human myometrium through two novel membrane G protein-coupled receptors: potential role in functional progesterone withdrawal at term. Lordosis reflex intensity in rats in relation to the estrous cycle, ovariectomy, estrogen administration and mating behavior. Making sense of cross-talk between steroid hormone receptors and intracellular signaling pathways: who will have the last word Integration of rapid signaling events with steroid hormone receptor action in breast and prostate cancer. Phosphorylation of human progesterone receptors at serine-294 by mitogen-activated protein kinase signals their degradation by the 26S proteasome. Activation of progestin receptors in female reproductive behavior: interactions with neurotransmitters. Activation of the Src/p21ras/Erk pathway by progesterone receptor via cross-talk with estrogen receptor. The relevance of hypothalamic and hyphophyseal progestin receptor regulation in the induction and inhibition of sexual behavior in the female rat. Expression of intracellular progesterone receptors in rat brain during different reproductive states, and involvement in maternal behavior. Sequential inhibition of progesterone: effects on sexual receptivity and associated changes in brain cytosol progestin binding in the female rat. Dilute estradiol implants and progestin receptor induction in the ventromedial nucleus of the hypothalamus: Correlation with receptive behavior in female rats. Progesterone: examination of its postulated inhibitory actions on lordosis during the rat estrous cycle. Role of estrogen receptor and b in the induction of progesterone receptors in hypothalamic ventromedial neurons. Steroid and G protein binding characteristics of the sea trout and human progestin membrane receptor alpha subtypes and their evolutionary origins. Differentiation in male ferrets of a sexually dimorphic nucleus of the preoptic/anterior hypothalamic area requires prenatal estrogen. Inverse modulation of gamma-aminobutyric acidand glycine-induced currents by progesterone. Pregnenolone sulfate: a positive allosteric modulator at the N-methyl-D-aspartate receptor.

Pertaining to the outer or more superficial layer of a twolayered membrane such as the pleura acne fighting foods order cleocin gel 20 gm on line, pericardium acne xenia gel cleocin gel 20 gm low cost, or glomerular capsule skin care 90210 generic 20 gm cleocin gel amex. Binds cells to extracellular materials and gives the tissue fluid a gelatinous consistency skin care laser clinic 20 gm cleocin gel order free shipping. A cell or organ specialized to detect a stimulus skin care 11 year olds 20 gm cleocin gel for sale, such as a taste cell or the eye. A protein molecule that binds and responds to a chemical such as a hormone, neurotransmitter, or odor molecule. Pertaining to a genetic allele that is not phenotypically expressed in the presence of a dominant allele. A chemical reaction in which one or more electrons are added to a molecule, raising its free energy content; opposite of oxidation and always linked to an oxidation reaction. Treatment of a fracture by restoring the broken parts of a bone to their proper alignment. A period of time after a nerve or muscle cell has responded to a stimulus in which it cannot be reexcited by a threshold stimulus. A period of time after male orgasm when it is not possible to reattain erection or ejaculation. An internal fold or wrinkle in the mucosa of a hollow organ such as the stomach and urinary bladder; typically present when the organ is empty and relaxed but not when the organ is full and stretched. A chemical released by a cell to serve a physiological function, such as a hormone or digestive enzyme. Insulin shock, a state of severe hypoglycemia caused by administration of insulin. Spinal shock, a state of depressed or lost reflex activity inferior to a point of spinal cord injury. Electrical shock, the effect of a current of electricity passing through the body, often causing muscular spasm and cardiac arrhythmia or arrest. A modified, relatively dilated vein that lacks smooth muscle and is incapable of vasomotion, such as the dural sinuses of the cerebral circulation and coronary sinus of the heart. Pertaining to widely distributed general senses in the skin, muscles, tendons, joint capsules, and viscera, as opposed to the special senses found in the head only; also called somesthetic. Pertaining to the cerebral cortex of the postcentral gyrus, which receives input from such receptors. An elongated structure that is thick in the middle and tapered at the ends (fusiform). A football-shaped complex of microtubules that guide the movement of chromosomes in mitosis and meiosis. A pointed process or sharp ridge on a bone, such as the styloid process of the cranium and spine of the scapula. A cellular shape that is flat or scaly; pertains especially to a class of epithelial cells. A mechanical force applied to any part of the body; important in stimulating bone growth, for example. A condition in which any environmental influence disturbs the homeostatic equilibrium of the body and stimulates a physiological response, especially involving the increased secretion of certain adrenal hormones. A phenomenon in which multiple stimuli combine their effects on a cell to produce a response; seen especially in nerve and muscle cells. A phenomenon in which multiple muscle twitches occur so closely together that a muscle fiber cannot fully relax between twitches but develops more tension than a single twitch produces. G-17 symport A cotransport protein that moves two solutes simultaneously through a plasma membrane in the same direction, such as the sodium­glucose transporter. A gap junction between two cardiac or smooth muscle cells at which one cell electrically stimulates the other; called an electrical synapse. For example, neither follicle-stimulating hormone nor testosterone alone stimulates significant sperm production, but the two of them together stimulate production of vast numbers of sperm. T target cell A cell acted upon by a nerve fiber, hormone, or other chemical messenger. T cell A type of lymphocyte involved in nonspecific defense, humoral immunity, and cellular immunity; occurs in several forms including helper, cytotoxic, and suppressor T cells and natural killer cells. A state of sustained muscle contraction produced by temporal summation as a normal part of contraction; also called tetany. Spastic muscle paralysis produced by the toxin of the bacterium Clostridium tetani or other causes. The minimum voltage to which the plasma membrane of a nerve or muscle cell must be depolarized before it produces an action potential. The minimum combination of stimulus intensity and duration needed to generate an afferent signal from a sensory receptor. A major blood vessel, lymphatic vessel, or nerve that gives rise to smaller branches; for example, the pulmonary trunk and spinal nerve trunks. T tubule Transverse tubule; a tubular extension of the plasma membrane of a muscle cell that conducts action potentials into the sarcoplasm and excites the sarcoplasmic reticulum. U ultrastructure Fine details of tissue and cell structure, as far down as the molecular level, revealed by the electron microscope. G-18 ultraviolet radiation Invisible, ionizing, electromagnetic radiation with shorter wavelength and higher energy than violet light; causes skin cancer and photoaging of the skin but is required in moderate amounts for the synthesis of vitamin D. The inner or deeper layer of a two-layered membrane such as the pleura, pericardium, or glomerular capsule. A high-energy, penetrating electromagnetic ray with wavelengths in the range of 0. Y Y chromosome Smaller of the two sex chromosomes, found only in males and having little if any genetic function except development of the testis. Z zygomatic arch An arch of bone anterior to the ear, formed by the zygomatic processes of the temporal, frontal, and zygomatic bones; origin of the masseter muscle. Martin, Alexis, 986, 986 Saline, normal, 940 Saliva, 924, 953­954 Salivary amylase, 68, 953­954, 975 Salivary duct, 954 Salivary glands, 924, 945, 953­954 extrinsic (major), 953, 953 innervation of, 559, 563, 564, 953­954 intrinsic (minor), 953 microscopic anatomy of, 953, 954 parotid, 563, 564, 946, 953, 953 salivation by, 953­954 sublingual, 946, 950, 953, 953 submandibular, 563, 564, 946, 950, 953, 953 Salivation, 953­954, 1118 Salt. Q) fluids, 940 Subcutaneous tissue, 176, 177, 181­182, 182t Subdural space, 510, 511 Subendocardial conducting network, 718, 719 Sublingual ducts, 953 Sublingual gland, 946, 950, 953, 953 Submandibular duct, 953 Submandibular gland, 563, 564, 946, 950, 953, 953 Submucosa, 946­947, 947 of esophagus, 954 of large intestine, 983 of stomach, 956 Subscapular sinus, 808­809, 810 Substance abuse, 571 Substance P, 568, 583, 583, 960 Substantia nigra, 517, 518 Substrate, 66, 67, 67 Sucrase, 975 Sucrose, 57, 58, 59t, 980, 996 Sudoriferous glands. It carries oxygen and nutrients to the tissues and waste products to the lungs, liver and kidneys, where they can be removed from the body. It is called plasma and is composed of various salts and proteins dissolved in water. In between is a narrow layer called the buffy coat because of its buff or yellowish white colour. The buffy coat is composed mainly of cells of a variety of types, collectively known as white cells. In addition there are small cellular fragments, called platelets, which have a role in blood clotting. The blood cells are then preserved by exposure to the alcohol methanol, a process known as fixation. The fixed film of blood is stained with a mixture of several dyes so that the individual cells can be recognized when they are examined with a microscope. After staining, the colour of red cells is enhanced and the white cells and platelets, which would otherwise be transparent and colourless, have acquired a variety of colours that allow their detailed structure to be recognized. Red cells the most numerous cells in a blood film are the red cells, also known as erythrocytes. Red cells owe their pinkishbrown colour to the pres ence of a complex protein, haemoglobin, which is their major constituent. The small structures containing lilacstaining granules between the red cells are platelets. In the body it is haemoglobin of the red cells that, in the lungs, combines with oxygen from inspired air and transports it to tissues where it is needed for the metabolic processes supply ing the energy needs of the body. Mature red cells in humans (although not in some other species) differ from most body cells in that they do not have a nucleus. Red cells are produced in the bone marrow and usually lose their nuclei when they are released into the blood stream. White cells are divided into granulocytes (also known as poly morphonuclear leucocytes) and mononuclear cells. The names are not very logical but they have been in use for a long time and are generally accepted. The term polymorphonuclear leucocyte refers to the very variable nuclear shape that is typical of granulocytes. However, this is true of granulocytes, as well as of the cells conventionally referred to as mononuclear. The cytoplasm of neutrophils is very pale pink and is packed with fine lilac staining granules. The visible granules are actually the primary or azurophilic granules, the secondary or specific granules being invisible by light microscopy but conveying the pink tinge to the cytoplasm. They spend 6­10 hours in the blood stream before moving from capillaries into tissues, where they have a lifespan of 1-2 days. They move pref erentially to sites of infection or inflammation where they ingest, kill and break down bacteria. The granules are referred to as eosinophilic because they take up the acidic dye eosin. They respond to chemotactic stimuli, are phagocytic and can kill ingested organisms. The secondary granules are referred to as basophilic because they take up basic components of the stain (such as methylene blue). In fact they stain metachromatically with basic stains, that is, the granules react with a blue dye to produce a purple colour. Basophils are produced in the bone mar row and circulate in the blood in small numbers, for many days, before migrating to tissues. They have a role in defence against helminth infections and in allergic and inflammatory responses. Lymphocytes Lymphocytes are the second most numerous circulating white cell after neutrophils. They are smaller than granulocytes, with a round or somewhat irregular outline and pale blue, clear cytoplasm. The Blood Film and Count 9 Some lymphocytes have a variable number of azurophilic (pinkishpurple) granules. Lymphocytes are divided into three morphological categories, depending on their size, the amount of cytoplasm and the presence or absence of cytoplasmic granules. The nuclear chromatin of lymphocytes may be dense and homogeneous (particularly in small lymphocytes) or more lightly staining and somewhat heterogeneous (particularly in large lymphocytes). Lymphocytes are produced from lymphoid stem cells in the bone marrow and probably the thymus. Their function is in tissues such as lymph nodes, spleen, tonsils and the lymphoid tissue associated with mucous membranes. They circulate in the blood stream, enter lymphoid tissues and emerge again from lymphoid tissues into lymphatic channels, where they form one constituent of a clear fluid known as lymph. This process of continuing movement between tissues and the blood stream is known as lymphocyte recirculation. B cells differentiate in tissues into plasma cells, which secrete antibod ies, thereby providing humoral immunity. T cells also modulate B cell function, having both helper and suppressor functions. The functional categories of lymphocytes are of far more importance than the morphological categories. They have lobulated nuclei and voluminous cytoplasm that is grey ishblue, is sometimes opaque and may be vacuolated or contain fine azurophilic granules. They function mainly in tissues where they differentiate into long lived macrophages (sometimes called histiocytes). Lymphocytes have clear, pale blue cytoplasm and discrete, sometimes prominent granules whereas monocytes usually have more opaque, greyblue cytoplasm with very fine granules. Monocytes differentiate not only into macrophages but also into various specialized cells, specific to different organs, such as the Kupffer cells of the liver, the microglial cells of the brain and the osteoclasts of bone. Platelets Platelets are produced within the vascular channels (sinusoids) of the bone marrow by the fragmentation of the protruding cyto plasm of large bone marrow cells known as megakaryocytes. They are thus not, strictly speaking, cells but rather are fragments of the cytoplasm of cells. They are pale blue with fine azurophilic gran ules, which tend to be clustered in the centre of the platelet. When blood films are made, as is generally the case, from anticoagulated blood, the platelets are usually discrete and separate from each other, but in some circumstances they form clumps or aggregates. Proliferation of cells occurs simultaneously with maturation or differentiation so that one myeloblast is likely to give rise to 16 mature granulocytes and one proerythroblast to 16 red cells. Myeloblasts, promyelocytes and myelocytes are all cells capable of cell division, or mitosis. All red cell precursors, with the exception of late erythroblasts, are dividing cells. Myeloblasts differentiate not only into neutrophils, as shown in the diagram, but also into eosinophils and basophils. The only significant function of haemopoietic cells is the production of mature end cells. Recognizable haemopoietic precursors are present in the circulating blood of healthy subjects but, except in the neonatal period and during pregnancy, they are quite uncom mon and are not often noted in a blood film. They are much commoner in patients with leukaemia or other haematological disorders and in patients with severe infection or other serious systemic diseases. The myeloblast has a high nucleocytoplasmic ratio, a diffuse chromatin pattern and a single nucleolus.

Order cleocin gel 20 gm online. Proactiv Face Brush & Clarisonic vs. Washcloth.

Effect of photoperiod on the mechanical response of the pregnant rabbit uterus to oxytocin skin care routine for dry skin 20 gm cleocin gel buy mastercard. Possible contribution of position in the litter huddle to long-term differences in behavioral style in the domestic rabbit acne 10 dpo 20 gm cleocin gel buy. Mimicking natural nursing conditions promotes early pup survival in domestic rabbits skin care images buy 20 gm cleocin gel overnight delivery. The action of oestrin on the uterus of the hypophysectomized and of the pregnant rabbit skin care tips for winter buy generic cleocin gel 20 gm on-line. The effect of oestrin on the uterine reactivity and its relation to experimental abortion and parturition skin care kemayoran cleocin gel 20 gm buy low cost. The action of progesterone on the uterus of the rabbit and its antagonism by oestrone. Diurnal nursing pattern of wild-type European rabbits under natural breeding conditions. Optimal litter size for individual growth of European rabbit pups depends on their thermal environment. Long-term consequences of early development of personality traits: A study in European rabbits. Separating maternal and litter-size effects on early postnatal growth in two species of altricial small mammals. Features of the early juvenile development predict competitive performance in male European rabbits. General tissue characteristics of the lower urethral and the vaginal walls in the domestic rabbit. Neural control of the female urethral and anal rhabdosphincters and pelvic floor muscles. Tissue alterations in urethral and vaginal walls related to multiparity in rabbits. Strain differences in the endocrine basis of maternal nest-building in the rabbit. Maternal behavior in the rabbit: Critical period for nest building following castration during pregnancy. Maternal behaviour in the rabbit: evidence for an endocrine basis of maternal nest building and additional data on maternal-nest building in the Dutch-belted race. Jay Rosenblatt (then director of the Institute of Animal Behavior at Rutgers University) were interested in exploring the underlying neuroendocrine control of the "peculiar" form of parental care displayed by this mammal (see below). Beyer had already performed several studies on the neuroendocrine control of lactation in rabbit does, together with Flavio Mena (see Chapter 10 by Hoffman et al. Rosenblatt, by contrast, was a pioneer of the studies on maternal behavior and had numerous publications, mostly in rats. Together, we have started a line of research aimed at investigating the underpinnings of the ways by which particular brain regions and somatosensory stimuli orchestrate the timing of rabbit nursing. Maternal behavior in mammals has been the subject of study in hundreds of papers published during the last 60 years. The approaches used to investigate this topic have ranged from the ethological to the evolutionary, and have employed a multiplicity of experimental methodologies (for reviews, see González-Mariscal and Melo, 2013; González-Mariscal and Poindron, 2002; Numan and Young, 2016; Rosenblatt and Siegel, 1981). Such studies have revealed the intricate web of neural connections that participate in regulating the expression of specific aspects of maternal behavior, the hormones that promote or inhibit particular maternal activities, and the many forms of care that female mammals have adopted to successfully meet the needs of their young. They tell us little about the mechanisms by which the elements of the "maternal brain" interact with each other on a higher level to allow the emergence of the most complex behavioral task shown by mammalian females during specific periods of their lifespan. It is the purpose of this chapter to present the behavior of mother rabbits in a way that will illustrate the complexities of this activity (for a recent review, see González-Mariscal et al. To this end we will use two theoretical frameworks: complex (or dynamic) systems and chronostasis. The former approach has been used successfully to gain insight on issues as diverse as the mind-brain relationship, the evolution of specific traits, the operation of insect societies, embryology, the production of crops worldwide. In psychology, this view has been adopted to investigate the development of cognition (Sporns et al. Moreover, recent progress in the neurosciences is making it possible to ground the concept of emergence in specific neural mechanisms (Sporns et al. Does it involve both the "unfolding" of a preexisting genetic program and the emergence of new traits as a consequence of interactions among the elements of the system in real time Similar questions were already posed by Rosenblatt and Lehrman (1963), coinciding with the ideas of Schneirla (1957) on the organization of behavior across stages (levels) of development. Because the structural properties of the system determine its stability (or lack thereof) in relation to the environment, one studies the dynamics of the system. From these properties follows the conclusion that the phenomena at a particular level of organization cannot be explained or predicted by the phenomena or principles that apply at lower levels. They emerge from their burrows at dusk to forage communally and they return to their subterranean quarters before sunrise (Mykytowycz, 1958, 1959). These nocturnal habits have been retained in animals housed under laboratory (Jilge, 2001) or farm (González-Mariscal et al. Despite their social behavior, females are very exclusive when it comes to maternal care: from midpregnancy until parturition, they gradually build a maternal nest totally separated 190 Behavioral Neuroendocrinology from the colony dwelling. This process begins with digging an underground burrow, continues with the collection of grass (carefully selected to be edible; Hudson and Altbäcker, 1992) and lining of the burrow, and concludes as the doe plucks her body fur (mainly from her ventrum and inner thighs) and covers the "straw nest" with it (Ross et al. This three-stage nest building process is displayed only by pregnant rabbits and it is tightly controlled by specific hormonal combinations. Thus, digging increases under the combined action of estradiol (E) and progesterone (P), a condition characteristic of early to mid-pregnancy (González-Mariscal et al. Although estrous does can also dig, they do it irregularly and less intensely than do the pregnant ones, and ovx females rarely express this activity. A decline in the concentration of P triggers a switch between behaviors, that is, a cessation of digging and an onset of straw carrying. Rabbits not exposed to P never collect straw and introduce it into the nest box: when given this material, they eat it. A View of Rabbit Maternal Behavior 191 treated as food under the combined influence of E and P, straw becomes "construction material" as the concentration of P declines. These changes are not dependent on the embryos, as the same behavioral switches are observed in ovx rabbits given E + P followed by discontinuing P (González-Mariscal et al. This is the only time when a female rabbit will perform this behavior, and we have obtained evidence that cognition may play a role in it. Thus, shaved females will readily collect fur from a container and introduce it into the straw nest, but the latency to do this depends on the type of fur offered: while they collect their own or synthetic fur almost immediately, it takes them around 20 min to start collecting male fur. Moreover, if shaved pregnant rabbits are given both straw and fur, they will collect only the former in late pregnancy and will start collecting fur later on, as parturition approaches (González-Mariscal et al. The way in which the various stages of nest building are linked to each other, and are stimulated/terminated by specific hormonal combinations, indicates that the relationships between the hormonal and behavioral levels of organization are nonlinear, that is, small quantitative changes provoke qualitative discontinuities. Although the above evidence supports a major role of E and P in determining the nest building sequence, our knowledge about the substrate(s) on which these hormones act is scarce. In rabbits it participates in controlling functions as diverse as female sexual receptivity, male mounting, scentmarking (Melo et al. Indeed, the latter are behavior patterns characteristic of estrous does because, as rabbits are reflex ovulators, they are not exposed to P unless they mate and a corpus luteum is formed (Ramírez and Beyer, 1988). This speculation is, of course, testable and has the advantage that one can use the presence or absence of P receptors as a means of identifying specific neuronal populations. Yet, unlike most mammals, nursing in rabbits occurs only once a day with a periodicity of ca. This apparent invariability in duration and frequency of nursing is critically dependent on the characteristics of suckling stimulation. Mother rabbits given only one kit to nurse stay a much longer time inside the nest box than do those given four young; however, providing a larger litter does not reduce the time inside the nest box below ca. Similarly, does suckling litters of four or fewer kits show a disruption in nursing periodicity, entering the nest box several times a day (González-Mariscal et al. These results indicate that an excitability threshold is required to "turn on" as yet unidentified processes that determine the duration of mother/young contact at ca. Specifically, the circadian rhythms of locomotion, corticosterone, and several metabolic indicators shift in relation to the time of the single daily nursing bout (Escobar et al. This (putative) entity would, indeed, allow the incorporation of the metabolic changes of lactating does into their "normal" activities and rhythms. For instance, there is a major increase in food intake across lactation (GonzálezMariscal et al. Such increased metabolic demands may reflect the operation of rheostasis, that is, modifications in the "set point" of processes like food and water intake, energy partitioning, and so on. In addition, the peculiar nursing pattern of rabbit does requires that "the system" be ready at the appropriate time, regarding both milk output and behavior. Chronostatic regulation seems ideally suited to this end, as it allows different configurations of the timing system to deal with changes in the environment and in the organism itself. Do they promote plastic changes that favor the engagement of particular brain structures (and peripheral organs) to constitute transitory circuits that "work toward a common end" Several forebrain areas, for example, the ventromedial, lateral, and dorsomedial hypothalamus, the nucleus accumbens, and the paraventricular thalamic nucleus have been implicated in the display of food anticipatory activity. Yet, none of them is essential (Mistlberger and Rechtschaffern, 1984; Mistlberger and Mumby, 1992; Mistlberger et al. Although rabbits show circadian rhythmicity in the expression of locomotion, defecation (Jilge, 1991a,b), and corticosteroid secretion (Szeto et al. By contrast, there is experimental evidence supporting the existence of element (2). It is based on the finding that if kits are removed from the maternal cage after suckling and are returned several hours later, does can show the behavioral component of nursing much earlier than usual: 60% of mothers that suckled 4 kits entered the nest box and crouched over the litter at 6 h after the previous suckling episode. By contrast, all rabbits that nursed just one kit redisplayed nursing behavior at 6 and even 3 h later (González-Mariscal, 2007). These findings support the existence of a refractory period whose duration depends on the number of kits suckled. In rabbits, maternal responsiveness is lost in primiparous mothers separated from their litter at parturition but is retained in those that are multiparous (González-Mariscal et al. New properties emerge in the maternal brain that lead to adaptive behavior patterns which, in turn, enhance the likelihood of survival of the young and promote a more "finely tuned" maternal behavior. A different type of reorganization of the maternal brain is illustrated by the responsiveness to specific odors. Nonpregnant rodents, sheep, and rabbits are generally repelled by olfactory signals emanating from newborns, amniotic fluid, and placentas. As parturition approaches, the valence of these stimuli changes from being treated as repulsive to becoming attractive. Thus, females will readily consume the placentas, lick the amniotic fluids, and approach the newborn (Gregg and Wynne-Edwards, 2005; Kristal, 1980; Lévy et al. Recently we reported that, as early as pregnancy day 7, mother rabbits prefer the odors of kits to "neutral" ones, an effect not seen in virgin animals (Chirino and González-Mariscal, 2015). Both models show that mothers "resolve" the approach/withdrawal conflict under conditions of specific hormonal combinations and somatosensory stimuli. Although these changes also suggest a self-organization of the neural networks underlying placentophagia and the processing of olfactory signals, they differ from the "maternal experience" effects in that they are transitory. That is, only during a limited period will females (even multiparous ones) consume placenta and amniotic fluid or prefer odors emanating from the young. These properties characterize the anagenetic nature of the process, that is, a trend from the simple (the virgin female) to the complex (the maternal female). Yet, unlike other forms of behavioral development, maternal traits are lost by the end of lactation (weaning), and this loss is an essential condition to allow the reinitiation of a new reproductive cycle. Nonetheless, "the maternal brain" apparently retains characteristics that facilitate the future expression of complex cognitive, motor, and spatial tasks (reviewed in González-Mariscal and Kinsley, 2009; González-Mariscal and Melo, 2016). Thus, the expression of maternal behavior seems to permanently modify the animal, as occurs in other developmental processes. We hope that his many teachings, generosity, and "life wisdom" will encourage us to pursue noble academic ideals and produce scientific findings worthy of that which we received from him. Previous maternal experience affects accumbal dopaminergic responses to pup-stimuli. Reproductive experience increases prolactin responsiveness in the medial preoptic area and arcuate nucleus of female rats. Topography in the preoptic region: differential regulation of appetitive and consummatory male sexual behavior. Motherhood alters the cellular response to estrogens in the hippocampus later in life. Immunocytochemical detection of estrogen receptor alpha in the female rabbit forebrain: topography and regulation by estradiol. Changes in responsiveness to kit odors across pregnancy: relevance for the onset of maternal behavior. Anticipatory changes in liver metabolism and entrainment of insulin, glucagon, and corticosterone in food-restricted rats. American Journal of Physiology-Regulatory Integrative and Comparative Physiology 279:R2048­56. Persistence of metabolic rhythmicity during fasting and its entrainment by restricted feeding schedules in rats. American Journal of Physiology-Regulatory Integrative and Comparative Physiology 274:R1309­16. Metabolic correlates of the circadian pattern of suckling-associated arousal in young rabbits.

Once the pregnant rabbit begins to collect and carry straw acne scar treatment buy cleocin gel australia, the continued expression of this behavior is sensitive to external cues associated with the status of nest completion acne in ear cleocin gel 20 gm sale. In the laboratory skin care products reviews by dermatologists 20 gm cleocin gel order mastercard, a series of experiments indicated that sensory cues associated with a finished nest inside the nest box serve as an external signal to quench the motivation to carry straw (Hoffman and Rueda-Morales 2009) acne 30s order genuine cleocin gel. Dopamine signaling appears to participate in maintaining the motivation to carry straw skin care education safe cleocin gel 20 gm, as dopamine D1 and D2 receptor antagonists significantly shortened the duration of straw carrying bouts, without otherwise altering the expression of this behavior (Hoffman and RuedaMorales 2012). Thus, the motivation to perform straw carrying, which is initiated by the internal hormonal state and maintained by dopamine signaling, is subsequently quenched by the perception of specific external cues. Studies of persons who suffer from compulsive hand washing indicate that they often relied on subjective internal criteria as signals to stop washing, that is, when it "felt right" (Wahl et al. By contrast, healthy controls reported either that they did not use any criteria or that they used objective criteria: they stopped automatically or when their hands were visibly clean. Schizophrenia, like all neuropsychiatric disorders, encompasses a complex constellation of psychiatric symptoms, generally categorized as positive symptoms (psychosis), negative symptoms (anhedonia, lack of motivational drive) and cognitive symptoms (specific deficits in working and episodic memory). While it is impossible to fully replicate schizophrenia (or, indeed, any neuropsychiatric disorder) in an animal model, nevertheless certain aspects of this disorder can be modeled and studied in nonhuman species. In the rabbit model, we found that glycinamide, a glycine prodrug that passes into the central nervous system and is converted to glycine (Beyer et al. Currently, there is interest in identifying pharmacological strategies that increase extrasynaptic glycine concentrations in the brain, as possible novel pharmacotherapies for schizophrenia. However, there have been few studies of the ontogeny of such differences- when they arise during development, if and how they relate to differences in morphology and physiology, or the mechanisms driving such processes (Stamps and Groothuis 2010; Trillmich and Hudson 2011), particularly in the case of mammals. Close observation and manipulation of mammalian young is often made difficult by their being hidden from view in nests, burrows, or pouches; experimental manipulation may lead to their being abandoned by the mother, and they are often defended by mothers or other care givers. The European rabbit, due to its unusual and highly stereotyped system of "absentee" mothering outlined above (see also Rödel et al. Starting in Tlaxcala but now also together with colleagues in other countries, we have been investigating the ontogeny of individual behavioral phenotypes in both domestic and wild European rabbits. We began this line of work by focusing on the contribution of differences in body mass and of interactions among littermates to early growth and survival (Drummond et al. In the rabbit, as in other altricial mammals, body mass at birth is closely associated with early postnatal survival and body mass at weaning (Rödel et al. Heavier pups at birth are also generally heavier at weaning than their lighter littermates, they occupy more central thermally advantageous positions in the litter huddle, obtain more milk, and are more efficient at converting this the Domestic Rabbit (Oryctolagus cuniculus) as a Model Animal 177 into body mass (Bautista et al. Within-litter differences in body mass at birth are, at least in part, due to the site of implantation of fetuses along the uterine horns. Those implanted at the ovarian end are generally heavier at birth and subsequently show greater weight gain and a higher probability of survival until weaning than their lighter littermates (Bautista et al. Being born into a nest of littermates confronts the young with an interrelated array of challenges and developmental possibilities. These can be broadly grouped according to two functional contexts: suckling and interactions within the litter huddle. Suckling is obviously essential for the young to obtain sufficient milk for survival and growth. Litter interactions within the huddle relate to the need to maintain an adequate body temperature and to obtain somatosensory stimulation necessary for normal neural, motor, and social development (Hudson et al. A high percentage of young fail to obtain milk during at least one nursing event and up to 20% die of starvation within the first postnatal week even under the relatively favorable conditions of the laboratory or farm (Couread et al. Competition is particularly severe given that the pups only obtain significant amounts of milk during the second minute of nursing (Bautista et al. Viewing the behavior of the young during nursing in a glassbottomed nest box showed that they compete for nipples in a vigorous scramble but without obvious signs of overt aggression. Body mass is a good predictor of suckling success and, independent of sex, the heaviest young at birth obtain more milk, are more likely to survive and are heavier at weaning than their lighter sibs (Drummond et al. Between suckling episodes the young also compete for well-insulated, central positions within the litter huddle, and expend considerable energy climbing over and burrowing under each other in a continuous effort to achieve and maintain such positions (Bautista et al. Body mass is a good predictor of the outcome of such struggles, with heavier young of either sex generally being in body contact with more littermates than their lighter sibs. Consequently, they also have higher body temperatures, lower expression of uncoupling protein-1 important in altricial young for burning brown fat for nonshivering thermogenesis (Bautista et al. They also have higher serum levels of testosterone and corticosterone at the end of the first postnatal week than their lighter sibs (Hudson et al. Aside from such competition, for any individual, littermates represent a significant thermoregulatory resource (Rödel et al. Young raised together, even with a single littermate, have higher mean body temperatures, are more efficient at converting milk into body mass, and have a higher probability of survival than littermates of similar body mass at birth and kept under the same conditions but alone (Bautista et al. Early sibling presence also appears to provide the young with somatosensory stimulation enabling them to anticipate and prepare for the daily nursing visit (cf. Hudson and Distel 1982; Jilge and Hudson 2001) and enhancing their motor development. Littermates raised together obtained more milk and had 178 Behavioral Neuroendocrinology better postural control than randomly chosen littermates raised alone (Nicolás et al. Early littermate presence might also contribute to later social competence, as littermates raised together competed more successfully for food and water postweaning than isolation-raised littermates of similar body mass (Nicolás et al. The findings outlined above show that relations among them help shape the early formation of individual profiles in morphological, physiological, and behavioral characteristics (Hudson et al. Certain characteristics of the rabbit might be "peculiar," but no more so than the unique characteristics of any other species, including the ubiquitously-studied rat and mouse. The physiology and behavior of every animal species were shaped through evolution, enabling that species to thrive in the face of a unique set of environmental and reproductive challenges. Thus, certain aspects of the physiology and behavior of any species, when considered with a comparative perspective and within the context of its phylogeny and natural history, can provide insight into fundamental biological processes. The "peculiarities" of the European rabbit can be viewed as providing exciting research opportunities, alongside the elegantly "simple" (and thoroughly mapped) nervous system of the nematode Caenohabditis elegans, the transparent embryos of the zebrafish Danio rerio, the monogamous lifestyle of the prairie vole (Microtus ochrogaster), the ability of the zebra finch (Taenio pygiaguttata) to learn songs, olfactory imprinting and homing behavior in the Pacific salmon (Oncorhynchus spp. Fourth international consultation on incontinence recommendations of the international scientific committee: Evaluation and treatment of urinary incontinence, pelvic organ prolapse, and fecal incontinence. Competition in newborn rabbits for thermally advantageous positions in the litter huddle is associated with individual differences in brown fat metabolism. Do newborn domestic rabbits Oryctolaguscuniculus compete for thermally advantageous positions in the litter huddle Scramble competition in newborn domestic rabbits for an unusually restricted milk supply. Intrauterine position as a predictor of postnatal growth and survival in the rabbit. Contribution of within-litter interactions to individual differences in early postnatal growth in the domestic rabbit. Synergistic actions of estrogen and androgen on the sexual behavior of the castrated male rabbit. Glycinamide, a glycine pro-drug, induces antinocioception by intraperitoneal or oral ingestion in ovariectomized rats. Failure of 5-dihydrotestosterone to elicit estrous behavior in the ovariectomized rabbit. Effects of hormones on the electrical activity of the brain in the rat and rabbit. Differential effect of testosterone and dihydrotestosterone on the sexual behavior of prepubertally castrated male rabbits. Effects of vigilance and other factors on nonspecific acoustic responses in the rabbit. Electrophysiological study of projections from mesencephalic central gray matter to forebrain in the rabbit. Morphometry of paravaginal ganglia from the pelvic plexus: impact of multiparity, primarity, and pregnancy. The concentrations of progesterone, estrone and estradiol-17 in the plasma of pregnant rabbits. Effect of removing the chin gland on chin-marking behaviour in male rabbits of the New Zealand race. Temporal coordination of pelvic and perineal striated-muscle activity during micturition in female rabbits. Anatomical and physiological characteristics of perineal muscles in the female rabbit. The contribution of the olfactory and tactile modalities to the nipple-search behaviour of newborn rabbits. Competition for milk in the domestic rabbit: survivors benefit from littermate deaths. Differences in morphology and contractility of the bulbospongiosus and the pubococcygeus muscles in nulliparous and multiparous rabbits. Major role of suckling stimulation for inhibition of estrous behaviors in lactating rabbits: acute and chronic effects. Differential metabolism of brown adipose tissue in newborn rabbits in relation to position in the litter huddle. Intracerebroventricular injections of prolactin counteract the antagonistic effect of bromocriptine on rabbit maternal behaviour. Prolactin stimulates emission of nipple pheromone in ovariectomized New Zealand white rabbits. Forebrain implants of estradiol stimulate maternal nest-building in ovariectomized rabbits. Hormones and external factors: are they "on/off" signals for maternal nest-building in rabbits Maternal behavior in New Zealand white rabbits: quantification of somatic events, motor patterns, and steroid plasma levels. Variations in chin-marking behavior of New Zealand female rabbits throughout the whole reproductive cycle. The Domestic Rabbit (Oryctolagus cuniculus) as a Model Animal 181 González-Mariscal, G. Chin-marking behavior in male and female New Zealand rabbits: onset, development, and activation by steroids. Pharmacological evidence that prolactin acts from late gestation to promote maternal behavior in rabbits. Electrical stimulation of the hypothalamus and the mechanism of neural control of the adenohypophysis. The excretion of an antidiuretic substance by the kidney, after electrical stimulation of the neurohypophysis in the unanaesthetized rabbit. Stimulation of the supraopticohypophysial tract in the conscious rabbit with currents of different wave form. Induction of ovulation in the hypophysectomized rabbit by administration of anterior lobe extracts. Progesterone, estradiol and testosterone levels in ovarian venous blood of pregnant rabbits. Cholesterol storage and progestin secretion during pregnancy and pseudopregnancy in the rabbit. Progesterone receptor activation signals behavioral transitions across the reproductive cycle of the female rabbit. Relevance of ovarian signaling for the early behavioral transition from estrus to pregnancy in the female rabbit. Toward an understanding of the neurobiology of "just right" perceptions: nest building in the female rabbit as a possible model for compulsive behavior and the perception of task completion. Relevance of mating-associated stimuli, ovulation and the progesterone receptor for the post-coital inhibition of estrous behavior in the female rabbit. The effect of siblings on early development: a potential contributor to personality differences in mammals. Sensitivity of female rabbits to change in photoperiod as measured by pheromone emission. Chin marking behaviour, sexual receptivity, and pheromone emission in steroid-treated, ovariectomized rabbits. Individual differences in testosterone and corticosterone levels in relation to early postnatal development in the rabbit Oryctolaguscuniculus. Effect of photoperiod and exogenous melatonin on correlates of estrus in the domestic rabbit. Parturition in the rabbit is compromised by daytime nursing: the role of oxytocin. Stable individual differences in separation calls during early development in cats and mice. Sibling competition and cooperation in mammals: challenges, developments and prospects. The occurrence of ovulation and pseudopregnancy in the rabbit as a result of central nervous stimulation. The occurrence of ovulation in the rabbit as a result of stimulation of the central nervous system by drugs. Visceral and postural reflexes evoked by genital stimulation in urethane-anesthetized female rats. A comparison of spontaneous and odor-induced chin marking in male and female domestic rabbits (Oryctolaguscuniculusdomestica). Striated muscles and scent glands associated with the vaginal tract of the rabbit. Multiparity causes uncoordinated activity of pelvic and perineal striated muscle and urodynamic changes in rabbits. Sexual behavior in the ovariectomized rabbit after treatment with different amounts of gonadal hormones. Differential development of body equilibrium among littermates in the newborn rabbit. Social behaviour of an experimental colony of wild rabbits, Oryctolaguscuniculus (L.

Joint Task Force on Practice Parameters; American Academy of Allergy acne whiteheads discount cleocin gel 20 gm overnight delivery, Asthma and Immunology; American College of Allergy skin care gadgets cleocin gel 20 gm on-line, Asthma and Immunology; Joint Council of Allergy skin care laser clinic cleocin gel 20 gm buy cheap, Asthma and Immunology skin care pakistan discount cleocin gel 20 gm buy online. Blood is required for three main functions: transportation of substances throughout the body acne solutions order cleocin gel 20 gm otc, regulation of normal physiologic conditions, and protection from hemorrhage and pathogenic invaders. Plasma is 92% water and 8% substances, including plasma proteins, electrolytes, vitamins, and other nutrients (ie, glucose, amino acids, and fatty acids). Plasma proteins are subdivided into albumins (60%), -, -, and -globulins (36%), and fibrinogen (4%). The genesis of any of the cellular constituents of blood originates from the hematopoietic stem cell, which resides in bone marrow. Granulocytes are basophils, eosinophils, and neutrophils, and arise from the myelogenous line of differentiation. Agranulocytes include monocytes and lymphocytes, which in turn can be subclassified into B cells and T cells. Oxygen delivery Blood is critical for oxygen delivery to vital organs and tissues. The adult human will consume 250 mL of oxygen per minute to provide for the basal metabolic rate. This rate equates to approximately 1 L/ minute of oxygen delivered to the body, well exceeding the basal demand of 250 mL/minute. Three mechanisms can supply the increased oxygen needed to meet this high demand: (1) increased oxygen absorbed from the lungs to the pulmonary vasculature, (2) increased cardiac output, and (3) increased unloading of oxygen to areas of increased demand. Increased concentrations of oxygen inspired will increase the volume of oxygen that reaches the pulmonary vessels. Increased unloading of oxygen at areas of increased demand is a manifestation of the physiology of hemoglobin. Under normal conditions, three variants of hemoglobin molecules exist, depending on the composition of, or subunits: hemoglobin A (22), hemoglobin A2 (22), or hemoglobin F (22). These factors facilitate the loading of oxygen onto hemoglobin in the lungs and the unloading in areas of higher oxygen demand. Normal or increased pH will tend toward increase oxygen affinity and oxygen binding. Tissue Increased temperatures from metabolism and increased oxygen demand decreases oxygen affinity, tending toward unloading. Hypoxia from increased oxygen metabolism results in lactic acid production, which will decrease pH and oxygen affinity, tending toward unloading. Hemostasis Of importance to the surgeon, regardless of specialty, is the ability for a physical insult to predictably heal. The healing process involves a complex array of events that must occur in both sequential and simultaneous fashion without interruption for tissue integrity to be re-established. This cascade of events begins by stopping the hemorrhage (hemostasis), minimizing blood loss, and stabilizing the wound, which enables the harmonious continuation of normal healing. The hemostatic process can be broken down into four component phases: (1) vascular, (2) platelet, (3) coagulation, and (4) fibrinolytic. Dysfunction of any element involved can alter the procession of the system as a whole to achieve success. Nitric oxide acts via a second messenger system, guanylate cyclase, and not only curtails platelet adhesion to the vessel wall and cohesion to other platelets but also promotes vasodilation. Platelet phase the vascular phase serves to decrease flow of blood to the site of injury. The platelets have a lifespan of 8 to 12 days and possess multiple structural elements and surface receptors that make it ideal for its positioning in the hemostatic process. Degranulation releases both and dense granules, each releasing different substances intricately involved in the platelet phase. The link closely relating the platelet phase to the clotting cascade involves procoagulant phospholipids. This model, though, does not account for the interrelationship between the intrinsic and extrinsic pathways. Basically two pathways, the extrinsic and intrinsic pathways, are involved and then converge to a common pathway, at factor X, resulting in the conversion of prothrombin to thrombin and the activation of fibrin. Warfarin (Coumadin, Bristol Myers Squibb) inhibits these vitamin K­dependent factors. With exposure of the subendothelial tissue as a consequence of vascular insult, a factoar extrinsic to the system, tissue factor (thromboplastin) is then expressed and in turn activates the extrinsic pathway. The hemostatic system involves numerous positive and negative feedback mechanisms that incorporate checks and balances. If this regulation fails to occur, thrombosis and eventual tissue damage is likely to occur. In addition to those platelet and vascular modifiers mentioned previously, antithrombin and activated proteins C and S are important here. When bound by heparin, be it exogenous or endogenous, the inactivation is increased by 1,000 to 4,000 times. Eventually, the clot must be reorganized to allow for re-establishment of the vessel wall and eventual tissue remodeling. Plasminogen, activated by tissue-type plasminogen activator, becomes plasmin, which then cleaves fibrinogen, primarily, but also acts on other coagulation factors and proteins used in the platelet and coagulation phases. As noted earlier, upon sustaining vascular injury, the body launches a series of events to minimize blood loss. However, these patients can see abnormal bleeding from even minimal tissue insult and extensive bleeding from significant injury. Diagnosis · Symptoms: Mucocutaneous bleeding, epistaxis, easy bruising, menorrhagia, and gastrointestinal bleeding. Both cryoprecipitate and Humate-P are derived from human tissue, so they carry the risk of disease transmission. Hemophilia A Pathophysiology and diagnosis Hemophilia A is a sex-linked recessive disease and affects males almost entirely. Thrombin, in turn, converts fibrinogen to fibrin, the main constituent of the initial clot. These patients often go undiagnosed, as their clotting ability is largely unaffected or minimally affected. These patients have increased risk for clinically significant bleeding from trauma or surgical insult, but they do not generally have spontaneous bleeding or hemarthrosis. Any degree of trauma or surgical insult will result in severe bleeding if untreated, including life-threatening intracranial hemorrhage. Genetic testing can reveal the sex-linked transmission of the disease from a known or unknown carrier. Spontaneous bleeding is generally seen when < 1% of factor is present, whereas > 5% of factor is sufficient to prevent bleeding unless traumatic or surgical insult is seen. Severe disease may require regular factor repletion to maintain adequate factor levels. Mild to moderate disease is generally managed when uncontrolled bleeding is encountered. When an initial dose of 50 to 60 units/kg is infused, nearly 100% activity level is seen. Smaller doses of 20 to 30 units/kg will generally elicit 30% to 50% activity level, sufficient for minor procedures. It is advocated to maintain this therapy for up to 4 to 6 weeks after a major surgical procedure, especially one involving bone and joints. Thus, an initial infusion of 100 units/kg should achieve near 100% factor activity levels. Smaller doses of 30 to 50 units/kg will provide 20% to 40% factor activity levels, sufficient for minor procedures. A normal hemoglobin molecule, hemoglobin A, has four subunits, including two subunits and two subunits. When glutamic acid is replaced by valine in the subunit, hemoglobin S (HbS) is formed. When oxygen tension is decreased (< 40 mm Hg) for a prolonged period (2 to 4 minutes) the geometry of erythrocytes with HbS changes from its normal circular, biconcave shape to a sicklelike shape. These cells cannot pass through the small diameters of capillaries, and occlusion results. Over time, organ damage will ensue, including the heart, spleen, kidneys, lungs, and brain. It can happen anytime the patient has a sickling crisis but is often associated with a pulmonary infection that causes the sickle cell crisis. When infection and trauma affect bones, local vascular stasis and hypoxia result, which triggers sickling in the area. The sickling in turn promotes further hypoxia and tissue damage, leading to infection of the bone. Occlusion of retinal vessels can result in vision changes and, ultimately, blindness. Hydroxyurea is converted to nitric oxide, which promotes vasodilation and inhibits platelet aggregation. Stanley and Christian15 have proposed a number of questions that will give the practitioner a better assessment of severity: 1. If the patient has an acute odontogenic infection or has sustained maxillofacial trauma, he or she may be in the middle of a crisis. Box 23-4 shows the common precipitants of crisis and perioperative efforts to avoid crisis. Stress · Anxiolysis can be accomplished with an oral premedication of diazepam or Versed (Roche). Infection · Antibiotic prophylaxis should be given before oral surgery procedures. If oral antibiotics can be given for a period to resolve the acute infection, then the procedure can be postponed until the risk of crisis has decreased. Vasoconstriction and stasis · Cardiac output should be maintained to minimize vascular stasis. Assuming this oxidation-reduction reaction mechanism is intact, accepted values for steady-state levels of methemoglobin under normal physiologic conditions are < 1% of the total hemoglobin concentration. When reduction of methemoglobin fails, the methemoglobin begins to accumulate with systemic effects manifesting rather rapidly. Physiologically, this equates to impaired tissue oxygenation as a result of the decreased propensity for oxygen to dissociate from the ferrous hemes and into the cells where demand is greatest. The ultimate consequence of this condition is system-wide cellular hypoxia that, if not recognized and properly treated in an expeditious manner, can then quickly result in the mortality of the patient. Patients who present with congenital causes typically appear cyanotic and, though some may complain of nonspecific symptoms such as headache and fatigue, are largely asymptomatic, despite methemoglobin levels of up to 40%. Patients who have the acquired form have a potentially life-threatening condition that is most often a result of contact with medication or other exogenous agents or contaminants. These substances increase the production of methemoglobin directly or through the production of oxidative free radicals subsequent to their metabolism (Box 23-5). An important fact to remember is that even standard doses of these medications can trigger the onset of methemoglobinemia, especially in the population of patients with a cytochrome B5 reductase deficiency. Box 23-6 can provide some key indicators that would suggest a diagnosis of methemoglobinemia as the systemic effects may closely resemble other pathologic processes. Formal diagnosis is confirmed in the laboratory through analysis of the absorption spectrum of methemoglobin with its peak of absorption being 631 nm. This is critical, especially in patients who have medical comorbidities where the oxygen delivery to tissues at baseline is already diminished, such as those with pre-existing cardiovascular or pulmonary disease as well as anemic patients. Therefore, careful attention must be given to a detailed medical history and initial physical exam prior to any anesthetic being administered, be it intravenous, local, or topical. Prudence should be exercised regarding dosage when known triggers for methemoglobinemia are being administered. With increasing concentrations of methemoglobin, the pulse oximeter reading converges on 85%. So, in the presence of high concentrations of methemoglobin, even an arterial oxyhemoglobin saturation of 20% will show an Spo2 of approximately 85%. Both the number of patients receiving anticoagulation therapy and the variety of anticoagulant medications are increasing. Several management strategies have been employed, including preoperative discontinuation of therapy with or without bridging, alteration of the dosage/regimen, and continuation of the regimen without interruption in therapy. The decision of which strategy to use should be made on a case-by-case basis and in conjunction with the clinician who is primarily managing the anticoagulation therapy. Clinicians must base this decision on the risk of a thromboembolic event resulting from subtherapeutic levels of anticoagulation relative to the risk of major bleeding. A unilateral decision by the oral surgeon to discontinue anticoagulation therapy is not recommended. Drugs Oral anticoagulant and antiplatelet medications all act on one or more of the steps of hemostasis. As mentioned previously, hemostasis is achieved is three main phases: the vascular phase, which entails vasoconstriction that facilitates the ensuing platelet phase; the platelet phase, which describes platelet aggregation and activation; and the coagulation phase, which results in maturation of the platelet plug to a fibrin-reinforced clot. Anticoagulants modulate the activation of thrombin and formation of fibrin, inhibiting the development of a thrombus. Antiplatelet drugs Many antiplatelet medications are commonly prescribed to patients with a history of coronary artery disease, myocardial infarction, stroke, angina, nonvalvular atrial fibrillation, and peripheral vascular disease. They are also given subsequent coronary artery stent placement and valve replacement surgery. It is generally agreed that antiplatelet therapy does not need to be interrupted before minor surgical procedures. However, in the acute setting of acute coronary syndrome and after having a percutaneous coronary intervention placed, a full dose, 325 mg, is given. Warfarin reaches peak plasma levels within 8 hours, has a half-life of 40 hours, and has a duration of up to 5 days, as warfarin must be cleared and new factors produced before normal coagulant function is seen. The effects of warfarin can be highly variable because of variability of the function of the P450 hepatic enzymes, age, body mass index, sex, dietary intake of vitamin K, alcohol consumption, and other comorbid diseases.

Additional information:

• Repaglinide
• Methoxsalen
• Roxithromycin

References

• Bachmann LH, Hobbs MM, Sena AC, et al: Trichomonas vaginalis genital infections: progress and challenges, Clin Infect Dis 53(Suppl 3):S160nS172, 2011.
• Duran M, Wanders RJA, de Jaguar JP, et al. 3-Hydroxydicarboxylic aciduria due to long-chain 3-hydroxyacyl coenzyme A dehydrogenase deficiency associated with sudden neonatal death: protective effect of medium-chain triglyceride treatment. Eur J Pediatr 1991;150:190.
• Kim JS, Judson MA, Donnino R, et al. Cardiac sarcoidosis. Am Heart J 2009;157(1):9-21.
• Spigelman AD, Williams CB, Talbot IC, Domizio P, Phillips RK. Upper gastrointestinal cancer in patients with familial adenomatous polyposis. Lancet 1989;ii:783.
• Lunn MP. Rituximab usage in CIDP: A retrospective e-mail based data collection. J Peripher Nerv Syst. 2009;(14):92.
• Day JD, Chen BL, Panneton JM. Bilateral renal vein thrombosis treated with percutaneous thrombolysis and mechanical thrombectomy. J Vasc Surg. 2009;50:1541.