Danielle Marie Brander, MD

• Assistant Professor of Medicine
• Member of the Duke Cancer Institute

https://medicine.duke.edu/faculty/danielle-marie-brander-md

An important step involves initial isolation or enrichment of a cell population of interest from the tissue source 7mm kidney stone treatment purchase cheap imusporin line. Cells such as T cells can be grown in nonadherent suspension culture where large-scale bioreactors such as bag-based and traditional stirred-tank vessels are used medicine mart order 100 mg imusporin with visa. This culturing system requires a small surface area and can produce a high cell yield symptoms glaucoma best order for imusporin. There is a growing interest in ex vivo expansion of adherent cells for a variety of clinical applications medications of the same type are known as generic imusporin 100 mg online. Mesenchymal stromal cells are grown adherently on tissue culture­treated surfaces but require a large surface area to produce on a large scale medications cause erectile dysfunction purchase 100 mg imusporin with mastercard. Such materials include culture media, sera, growth factors, cytokines and "feeder cells" that are used to support cell growth. They may be simple or complex and may remain in the final therapeutic product as active substances or as excipients. A qualification program for raw materials needs to be implemented to ensure the consistency and quality of raw materials and be designed to address identification and selection of the material, suitability of materials for use in manufacturing, characterization of materials, justification for use of animalderived materials. The range of infectious agents that produce little or no effect in animals may have severe consequences in humans. With xenogeneic materials, rigorous qualification of source animals and primary cell substrates is critical. Also, complex cell engineering procedures may extend over months and can result in an increased risk of contamination and other adverse effects. Quality control of the manufacturing process as well as the final product is necessary. Poor control of production processes can lead to the introduction of adventitious agents or other contaminants or to inadvertent changes in the properties or stability of the biologic product that may not be detectable in final product testing. However, they are inherently more limited and more variable because of individual patient characteristics and disease state. Use of allogeneic donors is associated with a greater risk than autologous donation because of the risk of infectious disease transmission from the donor to the recipient, the overall risk of an immune response, and donorto-donor variability. Allogeneic cells have the potential to treat hundreds of patients from a single manufactured lot of cells and can be an "off-the-shelf " product. Autologous products are patient specific and are manufactured using a "scaled out" approach. Cells are manufactured in small volume batches, and each patient constitutes his or her own "lot" of product. Allogeneic product manufacturing can use a "scaled up" approach with a bulk manufacturing strategy to produce larger volume batches. In summary, cell therapy products are being used in a variety of therapeutic indications. Characterization, although a predictor of efficacy, is not a predictor of safety or quality. Because full characterization is unlikely, it is imperative that manufacturing and aseptic processes be controlled and consistent to produce a safe reliable product. If manufacturing changes, as is often the case, essentially a new product is created and recharacterization, and repeat testing will be required to assess comparability of those changes. In contrast, the investigator is the individual who actually conducts the clinical trial and under whose direction the investigational product is administered. In many small cell therapy clinical trials, the sponsor may in fact also be the investigator so that the trial is conducted under a single individual who is designated as a sponsor/investigator. Information should be submitted to the agency 14 days before the meeting for type A meetings and 30 days before the meeting for type B and C meetings. The agency has designated meeting types to create a consistent level of support for products under development. This process is a collaborative process with the goal of moving the development into the clinical arena as quickly and as safely as possible. An attempt to organize the preclinical data to address these areas should be made. Toxicology studies, on the other hand, are critical to the initiation of clinical trials in humans. An adequate number of animals, typically of both sexes, and adequate sampling time points are required. The appropriate species include a proof of concept relevant animal model of the appropriate disease or injury and a healthy animal toxicology model. One study must include the same route of administration, the same cell manufacturing technique, and the same product as will be proposed in the clinical study. Deviations from this ideal should be clearly explained and justified scientifically. Written authorization must be obtained from the sponsor of the submission that is being cross-referenced. Specific details, including the submission and volume number and the heading and page numbers, should be provided to identify what material is being cross-referenced. Chemistry, Manufacturing, and Control Section Unlike chemical manufacturers that may produce a massive lot to treat multiple individuals, cell therapies are usually a single lot to treat a single individual. The drug substance is the starting material(s), including the procurement, process description, and test methods used to determine identity, strength, quality, and purity. The drug product is the end product, and its composition, manufacturing methods and packaging, and stability data should be included. Pharmacology/Toxicology Section the pharmacology/toxicology section must support the planned clinical trial. Shipping and Administration of Cellular Products Shipping is considered an extension of storage conditions. The shipping containers purchased must be validated by the laboratory before their use. This requires cell therapy expertise at the receiving site or significant training. Shipping validation procedures can be conducted to determine what tests are required for certain products. Establishing postshipment acceptance criteria is critical for the use of many cell therapy products. Practice runs are recommended for shipment of the product, especially if the timing of the administration is crucial. For example, if a product is to be administered during a surgical procedure, it will be important to know the product viability if there are delays in shipment or postshipment testing or the surgical procedure. In addition to a product meeting, the appropriate release criteria, the product administration process needs to be monitored. Patient baseline and postadministration evaluations are conducted, adverse events are documented, and any deviations from the product administration procedures or processes are recorded. Such documentation can allow the cell processing laboratory to evaluate common elements across different products as well as observe any product-specific trending. The cell population has been identified along with a manufacturing method and assays to characterize the consistency and key properties of the product. The manufactured product has been tested in animal models for both proof of concept data, including the route of administration, dosing schemes, and toxicology. The best way to make the transition from animals to humans smoothly is, if possible, to continue working with the same cell processing facility and staff that have been preparing the product throughout the preclinical studies. When this occurs, then it is easier to solve inevitable operational difficulties, attribute adverse events, and solve recruitment problems that may occur during the course of the trial. It is based on the manufacturing process and confirms that each step from raw material procurement to product release can be performed in a consistent and regulation-compliant manner. Trial Design Considerations the initial studies are safety based, typically at a single center, exposing few humans to the new therapy and carefully monitoring for adverse effects. As development continues, the clinical trial design can be broken down into two broad areas, scientific and operational. The scientific area includes the clinical questions to be answered and the statistical methods used to answer them. The investigator and the cell processing staff should meet early with statistical staff to determine how to phrase the clinical questions so that they can be answered with the proper end points. The statisticians will calculate the appropriate sample size that is required to answer the questions with sufficient statistical power. After the sample size has been derived, the investigators must determine if the trial can be conducted at one center or if a multicenter study is needed. Case report forms must be tailored to the study and need to be linked to the source data collected during the manufacture and delivery of the cells and throughout the clinical trial. The forms should be tested for ease of completion so that data coming in from the clinical sites will be easy to interpret. Data coordinators and research nurses should be given rigorous training on the completion of these forms and should know how long each form takes to fill out so they will be able to give a reasonable estimate of how many subjects they can follow within a given time period. The first operational details to be worked out are those involving the timing of manufacture and the delivery to the patient. If the trial must be conducted at multiple sites, will there be a central manufacturing site or will processing staff need to be trained at each recruitment site There are many translational steps to be completed before exposure to humans is feasible. These steps range from practical issues such as the shipment of cells to the complicated issues of preclinical studies to be performed in multiple animal models. Investigators need to develop good working relationships with the cell processing facility staff and statistical staff in order to complete an effective clinical trial. Guidance for Industry: Guidance for Human Somatic Cell Therapy and Gene Therapy, 1998. Draft Guidance for Industry: Potency tests for cellular and gene therapy products. General Information Chapter, Cell and Gene Therapy Products United States, Rockville, Md. Guidance for Industry: Source animal, product, preclinical, and clinical issues concerning the use of xenotransplantation products in humans. Brandenberger R, et al: Integrating process and product development for the next generation of biotherapeutics. Food and Drug Administration, Center for Biologics Evaluation and Research: References for the regulatory process for the Office of Cellular, Tissue and Gene Therapies. Food and Drug Administration, Center for Biologics Evaluation and Research: Information on submitting an investigational new drug application. Food and Drug Administration, Center for Biologics Evaluation and Research: Scheduling and conduct of regulatory review meetings with sponsors and applicants. Food and Drug Administration, Center for Biologics Evaluation and Research: Issuance of and response to clinical hold letters for investigational new drug applications. It is fortunate that the abbreviation can also be used to cover stem cells derived from placental and umbilical cord blood, which represent the next new source of cells for transplantation. Other sources, such as adipose tissue, are being discovered, and each may provide cells with specific properties that can be exploited for different applications. Facilities performing these procedures are increasingly involved in other types of cellular therapies. These include provision of cells for adjuvant therapies in the posttransplant setting and to support clinical trials in regenerative medicine. The dramatic growth in these new applications has attracted the interest of regulatory agencies, which have worked hard to develop an appropriate strategy to address a complex new area of medicine. An understanding of the regulations is therefore essential because they are based on the type of cellular therapy product. This was based on the presumption that the majority of posttransplant infections and admissions to intensive care units were attributable to receipt of contaminated products. If this was not the case, then the cells should be for autologous use, for use in a first- or second-degree blood relative, or for reproductive use. Cellular products that fall into this classification are referred to as Type 361 products. These products have been cultured ex vivo and transduced or activated ex vivo and therefore are more-thanminimally manipulated. These regulations were originally developed for the pharmaceutical industry to ensure that drugs are manufactured under a controlled and auditable process that ensures their safety, purity, and potency. Implementation of Part 1271 regulations has had an impact on the "routine" laboratory that prepares cells primarily for hematopoietic transplantation. In general, these cover personnel, procedures, facilities, environmental control and monitoring, equipment, supplies and reagents, recovery, processing and process controls, process changes, process validation, labeling controls, storage, receipt, predistribution shipment and distribution, records, tracking, and complaints. This should ensure that the appropriate regulations are being followed on an ongoing basis; that Chapter 98 Graft Engineering and Cell Processing 1493 mechanisms are in place for detecting, reviewing, and remediating errors and deviations from regulations, policies, and procedures; and that an audit program will be developed and implemented. Evidence of the work of the quality program must be documented, and the program should ideally be staffed by individuals who are not involved in hands-on manufacturing of the products. For Type 361 products, the facility must report, as Biological Product Deviations, any contaminated products that have been administered to a patient. Both organizations inspect based on standards that are published every 18 months to 3 years. Both organizations have worked to harmonize their standards with American, Canadian, Australasian, and European regulatory agencies; therefore, accreditation by either organization is of great assistance on the pathway to regulatory compliance. A number of other professional organizations accredit particular aspects of operations within the cell processing facility. As discussed previously, the degree of manipulation may determine the regulations under which the product is manufactured and handled. By contrast, more-than-minimal manipulation would include activities such as culture ex vivo, genetic modification, and ex vivo activation. This process is performed using techniques that were developed by the blood banking industry. Plasma depletion to remove donor antibodies that may react with recipient cells is achieved by centrifugation of the graft, usually in a transfer pack, at approximately 2000 g for 10 minutes at ambient temperature. The pack then is placed in a plasma expresser, which compresses the product bag so that plasma can be forced out and into a separate collection bag.

The advanced generation of packaging cells appears to be capable of generating pure stocks of recombinant virus without contaminating wild-type helper virus symptoms indigestion purchase genuine imusporin line, an important safety consideration treatment narcolepsy buy imusporin with mastercard. Indeed medicine games generic 100 mg imusporin overnight delivery, to date in human trials shinee symptoms mp3 discount imusporin 100mg overnight delivery, there have been no reports of inadvertent generation of infectious virus medicine januvia 100 mg imusporin buy with amex. Thus, this infection with replication-incompetent (ie helper-free) retrovirus vectors would be predicted to yield integration into the targeted cell population but no further spread of virus in the body of the treated patient. The proteins provided in trans for -retroviruses are generally gag, reverse transcriptase, and envelope proteins, the latter defining the host range of infection. Despite these advantages, the application of retrovirus vectors to treatment of human blood diseases in early trials was disappointing. In most studies, the frequency of circulating marked blood cells was too low to effect phenotypic correction of any disease, usually less than 0. The biologic parameters contributing to the poor results in human trials are varied. Practical issues, including the difficulty in obtaining high-titer virus in largescale preparations required for human trials, have also been noted. In addition to the energy in the field that was devoted to advancing stem cell transduction methodology, additional work focused on developing retroviral vectors that would express transgene cassettes at levels that would be high enough to elicit a therapeutic benefit and be resistant to gene silencing. Taken together, these technologic advances served as the platform for the first successful gene therapy trial in humans. The use of pharmacologic in vivo selection in combination with gene transfer, both in the setting of cancer trials and in genetic diseases, remains a potentially important method to enhance the reconstitution of human recipients with gene-modified blood cells but has not yet gained widespread usage. For applications in cancer therapies, dose intensification of drugs used within chemotherapeutic regimens should improve antitumor efficacy. For noncancer applications (most likely uses attempting co-selection of a nonselectable therapeutic gene in a genetic disease application), the mutagenic potential of the chemotherapy agent must be considered as a risk in relation to the overall benefit of the gene therapy Chapter 99 Principles of Cell-Based Genetic Therapies 1505 procedure. Several chemoresistance genes and chemotherapy drug combinations are currently under investigation for this application, and encouraging preclinical studies have led to a limited number of early phase human studies in cancer patients. As with gammaretroviruses, lentivirus vectors use key viral gene products in trans to generate replication-defective infectious particles carrying the transgene of interest. To date, most lentivirus vectors use vesicular stomatitis virus as envelope sequence, which provides a very broad range of target cells susceptible to lentivirus vector transduction. In the case of lentivirus vectors, viral gag and pol as well as tat and rev proteins expression are required in trans for efficient virus production along with the envelope proteins. These proteins are usually supplied from separate plasmids, and recombinant lentivirus production is today generally created using "four plasmid" systems encompassing all the necessary viral proteins on three plasmids and the transfer vector sequences on the fourth plasmid. Thus, generation of high-titer recombinant virus is more complicated than gammaretroviruses. This included viv, vpu, vpr, and nef genes and subsequently tat, an important regulator of viral transcription. Recombinant vectors generated without these sequences were demonstrated to efficiently infect a variety of cells. Lentivirus vectors were originally developed for use in a wide range of tissues in which cells are largely nondividing. Early work focused on brain,35,40 retinal cells,39 liver,41 pancreatic islets,42 airway epithelium,43 and muscle. In a trial for adrenoleukodystrophy, long-term "marking" in the myeloid compartment appears to be 10% to 20%, a level that is about 100-fold higher than the marking in the myeloid compartment seen in previous trials in immunodeficiency conditions that used gammaretrovirus vectors. However, the recent experience with a lentivirus vector used in a single patient with thalassemia,51 in which abnormal splicing resulted in clonal expansion in the erythroid compartment, suggests that insertion within genes may also have potential adverse effects on endogenous sequences. Thus, long-term safety of lentiviruses in human trials remains to be determined, and important aspects of insertional mutagenesis are described in more detail later. They have been shown to be endemic retroviruses in a wide range of animals but are not found in humans. These vectors are the largest of the retroviruses (14 kb) and thus yield vectors with a capacity to efficiently package large amounts of genetic sequences. As with gammaretrovirus vectors, the virus packaging signals have been successfully exploited to allow production of high-titer, replication-free vector stocks. Alpharetroviruses Retrovirus vectors derived from Rous sarcoma virus, which is a member of the alpharetrovirus family, have been described. When a genotypically matched family member is not available, haploidentical donors. Cells were subsequently infused without prior conditioning or cytoreductive treatment. In the French trial, 10 children younger than the age of 1 year were enrolled between 1999 and 2002. Much research has subsequently been directed at elucidating the mechanism responsible for these adverse events. Woods et al92 demonstrated lentiviral transduction of c-/- mice with vectors containing the human common chain (c) or an inert control gene at very high viral doses. They observed the induction of T-cell malignancies in one-third of the animals receiving c transduced cells but not in the control groups. However, outcomes after mismatched and haploidentical transplants are less impressive. All children on this trial are healthy and thriving, with the longest published follow-up time now more than 64 months. An increase in T-cell numbers and normalization of the proliferative response have been noted. More recently, Aiuti and colleagues104 have demonstrated that cellular genes in the proximity of the proviral integration site are subject to moderate dysregulation in gene modified T-cell clones isolated from patients. Rather, additional cooperating mutations or insertions are required for malignant transformation. However, the patient cohort remains relatively small, and follow-up is still short term. Indeed, this vector and treatment portfolio has been licensed in 2011 to a major pharmaceutical company for clinical development. The inability to form microbiocidal oxygen species renders the phagocytes unable to fight invasive infections. In previous clinical gene therapy trials conducted without myeloreductive conditioning, the engraftment level of gene modified cells remained low. The initial patients received a mild immunosuppressive preparative regimen and failed to engraft significant numbers of gene modified cells. Rather, starting 5 months after therapy, a less diverse integration pattern emerged, indicating the appearance of dominant clones. Clinically, following a period of cytopenia after the conditioning and cell infusion, the initial engraftment rates detected in the peripheral blood were 12% to 13%. Significant improvement in the previously refractory infections was noted 50 to 60 days after therapy. Surprisingly, a gradual increase in the number of gene-corrected cells up to 50% to 60% of all peripheral blood cells was observed, starting around day 150 after transplant. This coincided with increased oxidase activity and occurred in the absence of altered blood counts. A marked clinical benefit from gene therapy has been reported in one of the patients. Cerebral demyelination is associated with inflammation evident on gadolinium magnetic resonance imaging studies. Most patients progress from no symptoms to a vegetative state and death within 5 years of diagnosis. Myelin inflammation resolves, but lost neurologic function is not regained in successfully treated patients. Patients were preconditioned with cyclophosphamide and busulfan, and between 9% and 23% multilineage gene marked chimerism has been reported in a follow-up period that extends up to 16 months. A multisite, biotechnology-sponsored registration trial is currently being reviewed by regulators in several countries using a similar lentivirus vector in this disease. Clinically, this may result in transfusion-dependent anemia, which in turn can promote the serious side effect of iron overload. In general, disease severity correlates with the degree to which inactivation mutations inhibit -globin expression. However, other genetic loci can modulate the disease phenotype, for example, by inducing adult expression of the fetal -globin gene, which can be efficiently incorporated into functional hemoglobin in place of the -globin chain. Thus, an effective gene therapy vector must be able to facilitate high level expression of -globin in the range of that mediated by the normal endogenous gene in an erythroid-specific context. Of note, posttransplant molecular analysis revealed a mild clonal skewing comprising less than 5% of peripheral blood cells. This phenomenon, referred to as insertional mutagenesis, was characterized as a property of wildtype -retroviruses. Having greatly reduced the likelihood that retroviral gene therapy vectors could generate replication competent virus, the risk of a recombinant vector being able to transform a cell via insertional mutagenesis was initially perceived by many investigators to be very low. Conversely, preferential integration within the body of the primary transcript may result in lentiviral vectors having a higher probability of interrupting, for example, tumor suppressor gene expression or as noted earlier in the treatment of one patient with thalassemia in altering normal gene splicing. Progress has been made in the development of model systems to functionally evaluate the relative mutagenic potential of different vector systems. However, the model systems developed to date have a clear preference to detect mutagenesis mediated via upregulation of oncogene transcription. It is not clear whether this is a reflection of tumor suppressor gene inactivation being inconsequential as a mechanism of insertional mutagenesis or is a result of bias within the model system. Clearly, the preliminary results from the -thalassemia trial described earlier demonstrate that lentiviral vectors may mediate insertional mutagenesis via alternate mechanisms. As noted earlier, other related retroviral vector systems have also been shown to have an integration pattern that is distinct from gammaretroviral vectors and as such may represent a safer vector configuration. Recombinant foamy virus vectors do not preferentially integrate within genes, and their integration pattern does not significantly correlate with actively transcribed genes. These cells offer exciting possibilities for studying mechanisms of pluripotency; establishing models for disease-specific investigations; and enabling future applications in genetic and cellular therapies, including tissue engineering for regenerative medicine. Transplantation of these cells into irradiated recipients resulted in robust engraftment and amelioration of the sickle cell phenotype in transplant recipients. For example, the Dnmt3a and Dnmt3b methyltransferases become activated and silence the viral transgenes as endogenous pluripotency factors are transcriptionally reactivated. In addition, to date robust reconstitution of murine hematopoiesis has not been consistently demonstrated and there no successful reports of Chapter 99 Principles of Cell-Based Genetic Therapies 1511 in vivo reconstitution of human hematopoiesis in model systems. These all represent significant barriers to the translation of this powerful technology into human therapies. In addition, reprogramming has now been accomplished, albeit at lower efficiencies using both nonintegrating vectors and protein transduction. Several laboratories have demonstrated that targeting specific loci is associated with limited or no adverse effects on expression of neighboring genes (reviewed by Sadelain et al172). The frequency of directed site-specific integration in primary fibroblasts was as high as 10%. Thus, in some diseases, this therapeutic approach can now be considered an alternative to standard therapy. Insertional mutagenesis, which has resulted in serious adverse events in several trials, has stimulated rapid development of putative safer vector systems that are being tested in human trials but remains a challenge. Rapid progress in molecular technology, such as high-throughput sequencing and the development of new sources of expandable stem cell sources, offers significant potential for ongoing development of gene transfer in regenerative biology for a wide range of human conditions. I would like to thank members of my laboratory and particularly Michael Milsom and Lars Mueller for helpful discussions and members of the Transatlantic Gene Therapy Consortium for productive collaborations. Site-Directed Homologous Recombination to Correct Gene Mutations A long-standing but unrealized goal of genetic therapy has been homologous recombination to affect replacement of abnormal diseasecausing gene mutations. Other systems that seek to target specific genetic loci have also been described and are at different levels of development. Alternative methods in development include meganucleases188 and transcription activator­like effector nucleases. Li Z, Dullmann J, Schiedlmeier B, et al: Murine leukemia induced by retroviral gene marking. Naldini L, Blomer U, Gallay P, et al: In vivo gene delivery and stable transduction of nondividing cells by a lentiviral vector [see comments]. Berger F, Soligo D, Schwarz K, et al: Efficient retrovirus-mediated transduction of primitive human peripheral blood progenitor cells in stroma-free suspension culture. Naldini L, Blomer U, Gallay P, et al: In vivo gene delivery and stable transduction of nondividing cells by a lentiviral vector. Dull T, Zufferey R, Kelly M, et al: A third-generation lentivirus vector with a conditional packaging system. Miyoshi H, Blomer U, Takahashi M, et al: Development of a selfinactivating lentivirus vector. Blomer U, Naldini L, Kafri T, et al: Highly efficient and sustained gene transfer in adult neurons with a lentivirus vector. Trobridge G, Josephson N, Vassilopoulos G, et al: Improved foamy virus vectors with minimal viral sequences. Hu J, Ferris A, Larochelle A, et al: Transduction of rhesus macaque hematopoietic stem and progenitor cells with avian sarcoma and leukosis virus vectors. Fischer A, Cavazzana-Calvo M, De Saint Basile G, et al: Naturally occurring primary deficiencies of the immune system. Antoine C, Muller S, Cant A, et al: Long-term survival and transplantation of haemopoietic stem cells for immunodeficiencies: Report of the European experience 1968-99. Grunebaum E, Mazzolari E, Porta F, et al: Bone marrow transplantation for severe combined immune deficiency. Mazzolari E, Forino C, Guerci S, et al: Long-term immune reconstitution and clinical outcome after stem cell transplantation for severe T-cell immunodeficiency.

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Identification of medium/high-threshold extrinsic mechanosensitive afferent nerves to the gastrointestinal tract symptoms 7 days after ovulation order imusporin with amex. All calbindin-immunoreactive myenteric neurons project to the mucosa of the guinea-pig small intestine medications blood thinners order imusporin online. Electrical rhythmicity and spread of action potentials in longitudinal muscle of guinea pig distal colon treatment non hodgkins lymphoma buy discount imusporin 100 mg. Decreased fluid tolerance medications venlafaxine er 75mg cheap imusporin 100mg on-line, accelerated transit red carpet treatment order imusporin mastercard, and abnormal motility of the human colon induced by oleic acid. Stress-induced gastroduodenal motor disturbances in humans: possible humoral mechanisms. Electrophysiological mapping of fast excitatory synaptic inputs to morphologically and chemically characterized myenteric neurons of guinea-pig small intestine. Neuroendocrine Control of the Gut During Stress: Corticotropin-Releasing Factor Signaling Pathways in the Spotlight. Species dependent expression of intestinal smooth muscle mechanosensitive sodium channels. Sensory and motor responses to rectal distention vary according to rate and pattern of balloon inflation. Effect of a chloride channel activator, lubiprostone, on colonic sensory and motor functions in healthy subjects. Do corticotropin releasing factor-1 receptors influence colonic transit and bowel function in women with irritable bowel syndrome. Efficacy of on-demand asimadoline, a peripheral kappaopioid agonist, in females with irritable bowel syndrome. Paroxetine to treat irritable bowel syndrome not responding to high-fiber diet: a double-blind, placebo-controlled trial. Influence of acute serotonin reuptake inhibition on colonic sensorimotor function in man. A controlled crossover study of the selective serotonin reuptake inhibitor citalopram in irritable bowel syndrome. Roles of M2 and M4 muscarinic receptors in regulating acetylcholine release from myenteric neurons of mouse ileum. Synaptic Inputs to Morphologically Identified Myenteric Neurons In Guinea Pig Rectum From Pelvic Nerves. Perturbation of gastric emptying and duodenal motility through the central nervous system. Effects of alosetron on gastrointestinal transit time and Chapter 36 Neurophysiologic Mechanisms of Human Large Intestinal Motility 1021 452. Outer submucous plexus: an intrinsic nerve network involved in both secretory and motility processes in the intestine of large mammals and humans. Blockade of kit signaling induces transdifferentiation of interstitial cells of cajal to a smooth muscle phenotype. Distribution of alpha 2 agonist binding sites in the rat and human central nervous system: analysis of some functional, anatomic correlates of the pharmacologic effects of clonidine and related adrenergic agents. The effect of fluoxetine in patients with pain and constipation-predominant irritable bowel syndrome: a double-blind randomizedcontrolled study. Effects of an alpha(2)-adrenergic agonist on gastrointestinal transit, colonic motility, and sensation in humans. Comparison of simultaneous recordings of human colonic contractions by manometry and a barostat. A patient with localized megacolon and intractable constipation: evidence for impairment of colonic muscle tone. Serotonergic mediation of postprandial colonic tonic and phasic responses in humans. Mutation of the proto-oncogene c-kit blocks development of interstitial cells and electrical rhythmicity in murine intestine. Interstitial cells of Cajal in the deep muscular plexus mediate enteric motor neurotransmission in the mouse small intestine. Quantitative estimation of putative primary afferent neurons in the myenteric plexus of human small intestine. The effect of stress on colon motor and electrical activity in irritable bowel syndrome. Observations on the nervous control of the ileocaecal sphincter and on intestinal movements in an unanesthetized human subject. Participation of gastric mechanoreceptors and intestinal chemoreceptors in the gastrocolonic response. Idiopathic bile acid malabsorption-a review of clinical presentation, diagnosis, and response to treatment. The effects of methylnaltrexone alone and in combination with acutely administered codeine on gastrointestinal and colonic transit in health. Mechanisms of mechanotransduction by specialized low-threshold mechanoreceptors in the guinea pig rectum. A Ca(2)-activated Cl() conductance in interstitial cells of Cajal linked to slow wave currents and pacemaker activity. These cortical influences modulate reflex activity and also govern voluntary activity, which is important for socially adapted behavior related to urinary, anorectal, and sexual functions. From a clinical perspective, managing disorders of the lower urinary tract and anorectum requires understanding the anatomy and the highly integrated physiologic mechanisms responsible for micturition, urinary and fecal continence, and defecation. The premise of this chapter is that understanding the neuromuscular physiology of the anorectum will be enhanced by reviewing the neurophysiology of the lower urinary tract and, to a lesser degree, of human sexual functions. Together with the bladder and anorectum, the pelvic floor is responsible for storage and evacuation of urine and stool. The muscle components of the pelvic diaphragm are the levator ani, coccygeus, and puborectalis muscles. The the rectum is a tubular structure, approximately 15­20 cm in length, extending from the rectosigmoid junction of the colon to the anal orifice. The rectum has a dual embryologic origin: the upper rectum is derived from the embryologic hindgut and is able to distend toward the peritoneal cavity, whereas the lower rectum is derived from the cloaca and is surrounded by dense extraperitoneal connective tissue. The proximal 1 cm of the anal canal is lined by columnar epithelium, the middle 1. This assumes that the puborectalis muscle is part of the levator ani complex (see text). There are few enteric ganglia in the rectum compared with the colon and very few in the anal canal. These muscles do not have attachments to skeletal structures and, as with all true sphincters, contraction produces constriction of the lumen with little, if any, other movement. The superior surface of the bladder is covered by peritoneum, whereas the posterior surface, or base of the bladder, lies on the ventral aspect of the rectum in the male and on the vagina in the female. The remainder of the bladder is surrounded by an intermediate stratum of retroperitoneal connective tissue. In the male, the bladder is supported by the prostate and a condensation of intermediate stratum termed the puboprostatic ligaments. A similar condensation of endopelvic fascia, termed the pubovesical or pubourethral ligament, occurs in the female. In most general descriptions of gross anatomy of the bladder wall, three muscular layers are noted: outer longitudinal, middle circular, and inner longitudinal. It is probable that the arrangement most closely approaches a meshwork of musculature. A prominent detrusor band thickens toward the prostate as it progresses caudally where it divides and spreads around the neck of the bladder and base of the prostate. A further bundle of musculature that progresses from the anterior vesical neck Chapter 37 Neuromuscular Physiology of the Pelvic Floor 1025 posteriorly has been termed the bundle of Heiss. On the inner surface of the bladder is a mucosal layer composed primarily of transitional epithelium. Anatomically, the trigone is the triangle-shaped internal base of the bladder formed by ureteric muscles. In surgical practice, because the ureteral muscles are not particularly visible, the trigone is defined as a triangle formed by the ureteral orifices and the dorsal urethra. The muscular band that forms the base of the trigone is termed the interureteric ridge. The bladder is innervated by the vesical plexus, which is part of the pelvic plexus located on the lateral aspects of the rectum. Sympathetic innervation is derived from the T10­L2 cord segments, whereas parasympathetic innervation is derived from the S2­S4 spinal cord segments, which reach the pelvic plexus via the pelvic splanchnic nerves. The detrusor is primarily supplied by parasympathetic nerves; the bladder neck receives sympathetic innervation in the male, in contrast to parasympathetic innervation in the female. The sensory afferent fibers from the bladder accompany both the sympathetic and parasympathetic nerves to their respective spinal cord segments, as will be discussed in Section 37. The functional organization of pelvic floor/sphincter lower motor neurons is very different from other groups of motor neurons. This is distinctly different from the reciprocal innervation that is common in limb muscles. Thus, the pelvic floor is seen primarily as a functional unit in both closure systems of the urinary and gastrointestinal tracts, the support system for pelvic viscera, and as a participant in the sexual response. The anterior urethra may be divided into three parts: bulbous, penile, and glandular. The most recent recommendation is to use the term "urethral rhabdosphincter" to reflect the fact that the urethral sphincter is not external to the lower urinary tract but surrounds the middle of the urethra. Although there have been differing opinions as to whether there is additional innervation from the pudendal nerve, there is universal agreement that there is no additional innervation in non-human species. The location of the levator ani nerve on the intrapelvic surface of muscles has led to speculation that it is susceptible to damage during vaginal delivery and may contribute to the known correlation between parity and pelvic organ prolapse. Its position in relation to the bladder is somewhat analogous to the posterior urethra in the male. Composite drawing showing labeled afferent nerves in five equal and sequential sections representing an axial distance of 280 mm. It is likely that lateral interneurons provide an excitatory input () and medial interneurons in the dorsal commissure provide an inhibitory input () to sphincter motor neurons. A study in female rabbits demonstrated that the pubococcygeus muscle was active during bladder filling and quiet during micturition. Proprioceptive information is crucial for striated muscle motor control, both in the "learning" phase of a certain movement and for later execution of learned motor behaviors. Proprioceptive information is transmitted to the spinal cord by fast conducting, large diameter, myelinated afferent fibers and is influenced not only by the current state of the muscle, but also by the efferent discharge received by the muscle spindles from the nervous system via Y efferents. To decipher the state of the muscle, the brain must take into account these efferent discharges and make comparisons between signals sent to the muscle spindles along the Y efferents and signals received from primary afferents. From these more "direct" experiences of limb and eye movement, the brain can build a complex "awareness" of such activity. The sacral roots travel within the spinal canal from levels T12­L1 as the cauda equina. After passing through the intravertebral foramen, the spinal nerve divides into a dorsal ramus and a ventral ramus. The branches of the perineal nerve are more superficial than the dorsal penile/clitoral nerve and generally travel on the upper surface of the perineal muscle to innervate the urethral sphincter bilaterally. For example, there is still controversy as a result of anatomic studies of peripheral innervation of the pelvis which, as a rule, have been performed in a few cases. Interestingly, anatomic studies apparently dissect specimens only unilaterally, so that intersubject variability is noticed, but intrasubject variability (asymmetry) is not. Finally, much less is known about the finer details of central pathways to pelvic floor rhabdosphincters in humans, as most studies have been done in experimental animals. This is in contrast to other species, in which the motor neurons of the urethral and anal sphincters are located in separate nuclei. The dendrites project into the lateral funiculus, dorsally to the sacral parasympathetic nucleus, and dorsomedially toward the central canal. As this is similar to dendritic projections from the preganglionic neurons of the bladder, it suggests that both receive inputs from similar regions of the spinal cord. In addition to their morphology, the motor neurons of the rhabdosphincters are physiologically different from the neurons of skeletal muscle. They do not have monosynaptic inputs, Renshaw cell inhibition, or crossed disynaptic inhibition. Rhabdosphincter motor neurons are uniform in size and are smaller than the other sacral motor neurons. They are also distinguished by bundles of dendrites from multiple neurons projecting along transverse and longitudinal axes. The neurons demonstrate high concentrations of amino acid-, neuropeptide-, norepinephrine-, serotonin-, and dopamine-containing terminals that represent the substrate for the distinctive neuropharmacologic responses of 37. The afferent pathways from the anogenital and pelvic regions are commonly divided into somatic and visceral afferents. The visceral afferents accompany both parasympathetic and sympathetic efferent fibers, whereas the somatic afferents accompany the pudendal nerves and other direct somatic branches of the sacral plexus. Monosynaptic reflexes, which arise by the stretching of muscle spindles, are probably of little importance in pelvic floor sphincters. However, monosynaptic reflexes do play a major role in proprioception and are relevant for as yet poorly understood perceptions from pelvic organs, particularly from the rectum. All afferent neurons have their cell bodies in spinal ganglia; those accompanying somatic and parasympathetic pathways are in the sacral segments (S1/S2­S4) and those accompanying sympathetic fibers are in T11­L2 dorsal root ganglia. The sensory neurons are bipolar, sending Chapter 37 Neuromuscular Physiology of the Pelvic Floor 1029 long processes to the periphery and central processes into the dorsal column of the spinal cord or to the brain stem.

Over 20 years ago it was reported that protease activation in the pancreatic acinar cell required a low-pH compartment symptoms 0f gallbladder problems purchase generic imusporin canada. During starvation medicine journal impact factor cheap imusporin 100 mg online, induction of autophagy leads to enhanced breakdown of longlived proteins in the acinar cell treatment breast cancer discount imusporin online american express. However symptoms neck pain cheap imusporin 100 mg without prescription, when autophagy is associated with pancreatitis medicine expiration order 100mg imusporin amex, the opposite effect on protein degradation is observed; it is reduced. This "defective" autophagy includes a failure to break down activated digestive enzymes, such as trypsin, by specific lysosomal hydrolases. It is likely that the generation of active enzymes in the acinar cell is the consequence of two pathologic processes: (1) enhanced zymogen activation and (2) reduced degradation of active enzymes. Three pathologic acinar responses are responsible for this response: (1) reduced apical secretion, (2) enhanced basolateral secretion, and (3) increased paracellular permeability. The first involves the apical actin cytoskeleton, which may function to confine zymogen granules to the apical region of the acinar cell as required for apical exocytosis. Disruption of the apical actin cytoskeleton early in the course of pancreatitis may allow zymogen granules to diffuse away from their docking sites at the apical membrane. Second, endocytosis and membrane retrieval at the apical membrane are also inhibited; this response may block the recycling of critical factors required for exocytosis. In pancreatitis, zymogen granules redistribute to the basolateral regions where they can undergo exocytosis. The final pancreatitis response that contributes to diminished pancreatic secretion is an increase in paracellular permeability. Commensurate with disruption of the apical acinar cell actin network is fragmentation of the tight junctions and loss of the paracellular permeability barrier. The loss of this barrier allows contents of the pancreatic duct lumen to move into the interstitial space instead of traveling down the pancreatic duct. Cell death can occur by activation of programmed pathways (apoptosis) or necrosis. An emerging concept is that factors released by the acinar cell can stimulate innate immune responses. Although this was previously thought to occur by exposure to foreign products such as bacterial membrane lipids, recent studies have shown that products from sterile cell death can also activate these pathways. Thus, the death of acinar cells can stimulate innate immune pathways that increase inflammation and acinar cell death. Notch and Kras in pancreatic cancer: at the crossroads of mutation, differentiation and signaling. Periacinar stellate shaped cells in rat pancreas: identification, isolation, and culture. Identification, culture, and characterization of pancreatic stellate cells in rats and humans. Viscoelastic properties of human mesenchymally-derived stem cells and primary osteoblasts, chondrocytes, and adipocytes. Disruption of paracellular sealing is an early event in acute caerulein-pancreatitis. Paracellin-1, a renal tight junction protein required for paracellular Mg2 resorption. Enhanced secretion of amylase from exocrine pancreas of connexin32-deficient mice. Gap junction communication modulates [Ca] oscillations and enzyme secretion in pancreatic acini. Severe acute pancreatitis and reduced acinar cell apoptosis in the exocrine pancreas of mice deficient for the Cx32 gene. Chapter 49 Structure­function Relationships in the Pancreatic Acinar Cell 1359 23. Intramembrane-cleaving aspartic proteases and disease: presenilins, signal peptide peptidase and their homologs. Matrix proteins can generate the higher order architecture of the Golgi apparatus. Binding of the Golgi sorting receptor muclin to pancreatic zymogens through sulfated O-linked oligosaccharides. Resting (basal) secretion of proteins is provided by the minor regulated and constitutivelike pathways and not granule exocytosis in parotid acinar cells. Interaction of the cholinergic system and cholecystokinin in the regulation of endogenous and exogenous stimulation of pancreatic secretion in humans. Cholecystokinin at physiological levels evokes pancreatic enzyme secretion via a cholinergic pathway. Long distance communication between muscarinic receptors and Ca2 release channels revealed by carbachol uncaging in cell-attached patch pipette. Protease-activated receptor-2 protects against pancreatitis by stimulating exocrine secretion. Ca2 waves require sequential activation of inositol trisphosphate receptors and ryanodine receptors in pancreatic acini. Pilocarpine and carbachol exhibit markedly different patterns of Ca2 signaling in rat pancreatic acinar cells. Organelle selection determines agonist-specific Ca2 signals in pancreatic acinar and beta cells. Phasic release of newly synthesized secretory proteins in the unstimulated rat exocrine pancreas. The minor regulated pathway, a rapid component of salivary secretion, may provide docking/fusion sites for granule exocytosis at the apical surface of acinar cells. Actin coating of secretory granules during regulated exocytosis correlates with the release of rab3D. The subapical actin cytoskeleton regulates secretion and membrane retrieval in pancreatic acinar cells. A morphological study of the primary cilia in the rat pancreatic ductal system: ultrastructural features and variability. Role of cathepsin B in intracellular trypsinogen activation and the onset of acute pancreatitis. Impaired autophagic flux mediates acinar cell vacuole formation and trypsinogen activation in rodent models of acute pancreatitis. Impaired autolysosome formation correlates with Lamp-2 depletion: role of apoptosis, autophagy, and necrosis in pancreatitis. An evaluation of the expression, subcellular localization, and function of rab4 in the exocrine pancreas. Alcohol/cholecystokinin-evoked pancreatic acinar basolateral exocytosis is mediated by protein kinase C alpha phosphorylation of Munc18c. Role of actin in regulated exocytosis and compensatory membrane retrieval: insights from an old acquaintance. Other peptides can act in vivo to stimulate or inhibit secretion, but their physiological relevance is less clear. All of these agents interact initially with receptors on the plasma membrane of acinar cells. The steps following receptor occupancy that lead to secretion of either proteins or ions are generally referred to as stimulation-secretion coupling, a term coined in the pioneering work of Douglas. It is operationally useful to divide stimulussecretion coupling into consideration of transmembrane signaling, intracellular messengers, effectors, and exocytosis. Intracellular messengers include ions, cyclic nucleotides, phospholipids, and gaseous messengers. Effectors are the molecules activated by the intracellular messengers that are often involved in specific phosphorylation events. Finally, it has become clear that secretagogues trigger other regulatory events and pathways as well as those described in this chapter in order to mediate digestive enzyme synthesis and other acinar cell events. The third cytoplasmic loop is believed to be the primary site interacting with heterotrimeric G proteins, and the cytoplasmic carboxyl-terminal may be involved with receptor regulation such as desensitization and downregulation in response to both phosphorylation and interaction with other proteins. These G proteins are made up of -, -, and -subunits with the latter two normally existing as a complex. There are at least 16 -, 5 -, and 12 -subunits in the human and mouse genome, but the significance of this heterogeneity is not understood. All - and -subunits bear post-translational lipid modifications to mediate their attachment to membranes. The -subunit then dissociates from the complex and both can activate their effectors. Recent evidence suggests that activation can also involve a conformational change without full dissociation. The structural interactions between s and i with adenylate cyclase are becoming known. The activities of some cyclases can also be regulated by post-translational modifications including phosphorylation and nitrosylation. It is not clear, however, whether these are regulated by G proteins directly or by intracellular messengers. Both molecules are established as primary intracellular messengers in the exocrine pancreas. The development of our current understanding of this pathway has been extensively reviewed elsewhere and thus will only briefly be covered in this chapter. For example, in the 1950s, Hokin and Hokin first suggested the involvement of phosphoinositides in signal transduction after demonstrating that cholinergic stimulation increased 32P incorporation into polyphosphoinositides extracted from pigeon pancreas. Initially, Berridge demonstrated that agonists actually hydrolyze polyphosphoinositides and not phosphatidylinositol, resulting in the formation of inositol trisphosphate. The peak occurs within 5 seconds and subsequently decays to smaller but still elevated levels over time. Stimulation with maximal concentrations of secretagogues results in a characteristic "peak and plateau" type Ca2 signal. Readmission of extracellular Ca2 restores the plateau phase of the response indicating that Ca2 influx is required to maintain this portion of the response. This influx is not blocked by antagonists of voltage-gated Ca2 channels, but is attenuated by lanthanides. Indeed, it has been suggested that activation of this pathway is responsible for the inappropriate intracellular activation of trypsin that occurs in models of acute pancreatitis. The maximal global [Ca2]i reached during the release phase is generally between 200 nM and 1 M. Under these conditions, it was reported that a channel activated by arachidonic acid was predominately responsible for Ca2 influx. This interaction may impact the kinetics of InsP3 production and contribute to the agonistspecific characteristics of secretagogue-stimulated Ca2 signals in pancreatic acinar cells. However, by the nature of the measurements, the experiments represent the global [Ca2]i as a mean value integrated from throughout the cell. Digital imaging techniques, however, allow the monitoring of [Ca2]i at the subcellular level and in multiple cells of a coupled acinus. Probes are available with a choice of spectral characteristics and affinities for Ca2 and with the ability to be targeted to various cellular compartments. The combination of the flexibility of the probes plus the imaginative use of digital imaging techniques has revealed that the Ca2 signal displays remarkable spatial intricacy that appears to be fundamental for the appropriate activation of downstream effectors. Digital imaging of Ca2 indicators reveals spatial homogeneity in agonist-stimulated Ca2 signals. Ca2 signals are again initiated in the apical portion of the cell but remain in the apical third of the cell without spreading to the basal aspects of the cell (Ab­Ah). The kinetic recorded from an apical region of interest (yellow trace) and from the basal region (blue trace) demonstrates that [Ca2]i elevations are only observed in the apical pole of the acinar cell under these conditions. The kinetic shows the Ca2 changes in the apical (blue trace) versus basal pole (red trace) of the cell together with the activation of a chloride conductance as measured by whole-cell patch-clamp. This has been most elegantly demonstrated by focal flash photolysis of caged carbachol contained in a whole-cell patch-clamp pipette isolated in the base of the cell. The frequency of these transients corresponds to the frequency of oscillations noted in microfluorimetry studies. Further, this study demonstrated that Ca2 influx following store depletion could be detected earlier in the apical region when compared to more basal aspects of the cell. The propagation of a Ca2 wave between adjacent cells obviously requires relatively longrange messengers. The physiological function of propagating Ca2 waves in pancreatic acinar cells is not firmly established. A reasonable proposal, however, is that gap-junctional communication represents a mechanism to increase the responsiveness Chapter 50 Stimulus-secretion Coupling in Pancreatic Acinar Cells 1369 of an acinus to threshold concentrations of agonist. In this scenario, the acinus is rendered as sensitive to secretagogue stimulation as the pacemaker cell. In support of this idea, isolated single cells are much less sensitive to secretagogue stimulation than isolated acini;109 in addition experimental maneuvers that increase gap-junctional permeability lead to increased secretagogue-induced amylase secretion. The lack of viability results from a failure to ingest and subsequently digest food as a direct consequence of a general failure of exocrine gland secretion. The physical presence of RyRs has, however, been difficult to demonstrate in pancreatic acinar cells with conflicting positive and negative reports of expression. For example, in one study RyRs could be detected using Western analysis in salivary gland acinar cells but not in pancreatic acinar cells. Immunohistochemistry and studies with fluorescently labeled ryanodine have indicated that RyRs are distributed throughout acinar cells with perhaps the greatest concentration in the basal aspect of the cell. Once again the activity of this agent was first reported to play a role in invertebrate fertilization. Homeostasis is accomplished by a variety of pumps and transporters that have specific distribution on both the plasma membrane and on the membranes of various organelles. Tepikin and colleagues, employing a technique where the extracellular [Ca2] is monitored by an indicator in a small volume of extracellular fluid, demonstrated that Ca2 is extruded across the plasma membrane following agonist stimulation. Indeed, the rate of pumping has been shown to have a steep dependence on [Ca2]I (Hill coefficient of ~3) and is effectively saturated at [Ca2] above 400 nM. Mitochondrial Ca2 uptake occurs via a Ca2 uniporter as a function of the large electrical potential across the inner mitochondrial membrane.

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