By F. Hamil. Gonzaga University.
M olecular analyses revealed that intragraft display of m RN A encoding granzym e B proven 80mg super cialis, IL-10 generic super cialis 80 mg without prescription, or IL-2 correlates with acute rejection, and intrarenal expression of transform ing growth factor (TGF)-b1 m RN A is associated with chronic rejection. These data suggest that therapeutic strategies directed at the m olecular correlates of rejection m ight refine existing antirejection regim ens. Treatment FIGURE 9-9 IM M UNOSUPPRESSION Im m unosuppressive therapy protocols. Standard im m unosuppressive therapy in renal PROTOCOLS transplant recipient consists of 1) baseline therapy to prevent rejection, and 2) short courses of antirejection therapy using high-dose m ethylprednisolone, m onoclonal antibodies or poly- clonal antisera such as antilym phocyte globulin (ALG) and antithym ocyte globulin (ATG). Induction protocols Antilymphocyte globulin is prepared by immunizing rabbits or horses with human lymphoid Maintenance protocols cells derived from the thym us or cultured B-cell lines. Disadvantages of using polyclonal Early posttransplantation ALS include lot-to-lot variability, cum bersom e production and purification, nonselective targeting of all lym phocytes, and the need to adm inister the m edication via central venous Late posttransplantation access. Despite these lim itations, ALG has been used both for prophylaxis against and for Antirejection therapy the prim ary treatm ent of acute rejection. A typical recom m ended dose for acute rejection is 10 to 15 m g/kg daily for 7 to 10 days. The reversal rate has been between 75% and 100% in different series. In contrast to m urine m onoclonal antibodies (eg, O KT3), ALS does not generally induce a host antibody response to the rabbit or horse serum. As a result, there is a greater opportunity for successful readm inistration. INDUCTION PROTOCOLS Induction (panel A) and maintenance (panel B) immunosuppression protocols. These immunosuppressive protocols differ from center to center. There are numerous variations, but the essential features are 1) the prednisone dosage is high initially and then reduced to Standard induction a m aintenance dose of 10 to 15 mg/d over 6 to 9 months, and 2) the cyclosporine dosage is Corticosteroids 8 to 12 mg/kg/d given as a single or twice daily dose, and dosage is adjusted according to Azathioprine or mycophenolate trough plasm a and serum blood levels. To m aintain im m unosuppression provided by cyclosporine and to reduce the incidence of cyclosporine side effects, azathioprine or Cyclosporine or FK506 m ycophenolate has also been used with lower dosages of cyclosporine. The results of this Antibody induction triple therapy are excellent, with first-year graft survival greater than 85% reported in most OKT3 or antithymocyte gamma globulin instances and with a substantial num ber of patients having no rejection at all. Although this type of regim en was the m ost common, there have been a number of exceptions [2,10]. Recently, mycophenolate mofetil has been approved by the US Food and Drug Adm inistration for prophylaxis of renal transplant rejection. This agent was devel- oped as a replacem ent to azathioprine for maintenance immunosuppression. M AINTENANCE new immunosuppressive agent that has been approved by the FDA. FK506 is similar to IM M UNOSUPPRESSION cyclosporine in its mode of action, efficacy, and toxicity profile. FK506 may be beneficial in renal transplantation as rescue therapy in patients taking cyclosporine who have recurrent or resistant rejection episodes [12–14]. Cyclosporine or FK506 Mycophenolate Prednisolone ATG ATG OKT3 OKT3 Postantigenic M PA differentiation AZA ATG CD4 CD4 OKT3 ATG Class II OKT3 HLA antigen IL-1 TNF-α Steroids CD4 Stimulated Allogeneic cell CD4 CsA IL-2 macrophage M acrophage FK506 B lymphocyte M PA RPM IL-2 Steroids CD8 CD8 Class I IL-1 ATG ATG CD8 CD8 HLA antigen OKT3 OKT3 AZA M PA ATG ATG OKT3 OKT3 γ-Interferon A FIGURE 9-11 M echanism of action of im m unusuppressive drugs. A, The sites of interleukin (IL)-1 by m acrophages, cyclosporine (CsA) and FK506 action of the com m only used im m unosuppressive drugs. Im m uno- interfere with IL-2 production from activated helper T cells, and suppressive drugs interfere with allograft rejection at various sites azathioprine (AZA) and m ycophenolate m ofetil (M PA) prevent in the rejection pathways. Glucocorticoids block the release of proliferation of cytotoxic and helper T cells. CsA and FK506 block the transduction of the signal from the T- TCR TCR cell receptor (TCR) after it has recognized antigen, which leads Nucleus signal TCR Cyclosporin A signal TCR FK506 Nucleus to the production of lym phokines such as IL-2, whereas RPM blocks the lym phokine receptor signal, eg, IL-2 plus IL-2 receptor T lymphocyte (IL-2R), which leads to cell proliferation. The addition of a prophylactic course of antithym ocyte globu- LKR signal Il-2 lin (ATG) or O KT3 with delay of the adm inistration of CsA or IL-2R IL-2R FK506 during the initial postoperative periods has been advocat- LKR LKR ed by som e groups. O KT3 prophylaxis was associated with a signal TCR Rapamycin signal TCR Nucleus lower rate of early acute rejection and fewer rejection episodes Nucleus per patient. Prophylactic use of these agents appears to be m ost effective in high-risk cadaver transplant recipients, including those who are sensitized or who have two H LA-DR m ism atches Cell differentiation or a prolonged cold ischem ia tim e [2,10]. IFN -g— interferon B Cell proliferation gam m a; TN F-a— tum or necrosis factor-a. ANTIREJECTION THERAPY REGIM ENS Acute rejection Intravenous methylprednisolone, 0. A biopsy should be perform ed whenever Resolves on repeat biopsy possible. The first-line treatm ent for acute rejection in m ost centers is pulse m ethylprednisolone, 500 to 1000 m g, given intravenously daily for 3 to 5 days. The expected reversal rate for the first episode Evaluate OKT3 of acute cellular rejection is 60% to 70% with this regimen [15–17]. In this setting, O KT3 or polyclonal anti–T-cell antibodies should be considered. The use of these potent therapies should be confined to acute rejections with acute com ponents that are ATG or OKT3 ATG B potentially reversible, eg, mononuclear interstitial cell infiltrate with tubulitis or endovasculitis with acute inflammatory endothelial infiltrate [19,21]. ATG— antithym ocyte globulin; ICAM -1— intercellular adhesion molecule-1; LFA-1— leukocyte function-associated antigen-1. M AJOR SIDE EFFECTS OF IM M UNOSUPPRESSIVE AGENTS Mycophenolate Cyclosporine FK506 Azathioprine mofetil Nephrotoxicity +++ ++ Infection ++ + Neurotoxicity + ++ Marrow suppression ++ + Hirsutism +++ 0 Hepatic dysfunction + Gingival hypertrophy ++ 0 Megaloblastic anemia ++ 0????? FIGURE 9-13 Side effects of im m unosuppressive agents.
In laboratory animals generic super cialis 80 mg with amex, NMDA antagonists such as habituation buy super cialis 80 mg otc, PPI, or latent inhibition (1,3,9). Ac- impair working memory, set shifting, and other cognitive cordingly, 5-HT2A antagonism by itself might be effective functions that are related to schizophrenia (31). More im- in the treatment of certain forms of schizophrenia. Indeed, portantly, in clinical studies, direct comparison of schizo- a rather selective 5-HT2A antagonist, M100907, appears phrenic patients with healthy volunteers receiving subanes- to have efficacy as an antipsychotic in some patients with thetic doses of ketamine have indicated no significant schizophrenia, despite having negligible affinity for dopa- difference in scores for thought disorder between the two mine receptors (76). This finding suggests the possibility of groups (81). These drugs produce both locomotor hyperactivity and stereotyped behaviors. Al- Glutamatergic Models though they also increase dopamine neurotransmission in Dysfunctional glutamate neurotransmission has been impli- limbic regions (82), their motor-activating effects appear to cated in schizophrenia, primarily because noncompetitive be dopamine-independent (83). At rather low doses, PCP antagonists of the NMDA subtype of glutamate receptors, retards habituation of the startle response without affecting including PCP and ketamine, produce a behavioral syn- startle reactivity (84), a pattern similar to that seen in paral- drome in healthy humans that closely resembles symptoms lel studies in schizophrenic patients (9). Also as in schizo- of schizophrenia and is frequently misdiagnosed as acute phrenia, PCP-treated rats exhibit marked deficits in social schizophrenia (77,78). Although typical antipsychotics have no reliable symptoms, such as paranoia, agitation, and auditory halluci- effect on the PCP-induced disturbance in social behavior nations; negative symptoms, such as apathy, poverty of in rats, the atypical antipsychotics clozapine, sertindole, and thought, and social withdrawal; and cognitive deficits, such olanzapine appear to reverse the effects partially (22). The remarka- terms of sensorimotor gating measures, PPI is reduced or ble similarity of PCP-precipitated behaviors with the diverse eliminated in rats by psychotomimetic noncompetitive array of symptoms associated with schizophrenia has NMDA antagonists, including PCP, dizocilpine (MK-801), prompted the use of PCP (and its analogue ketamine) in and ketamine (14,15). As with apomorphine and as in schiz- pharmacologic models of schizophrenia in both basic and ophrenia, both intramodal and cross-modal PPI is sensitive clinical studies. Notably, whereas psychotic episodes are to noncompetitive NMDA antagonists (59). In contrast to 696 Neuropsychopharmacology: The Fifth Generation of Progress the effects of dopamine agonists on PPI, but in keeping with Isolation rearing of rats has also been used as a manipula- the results of studies of the subjective effects of ketamine in tion to generate models related to schizophrenia and models humans, the PPI-disruptive effects of NMDA antagonists of depression and attention-deficit/hyperactivity disorder are not reversed by typical antipsychotics such as haloperidol (ADHD). In the context of schizophrenia, the focus has or selective D1 or D2 antagonists. Importantly, these effects been on the disruptions of PPI rather than the locomotor are reversed by the atypical antipsychotics clozapine, olan- hyperactivity observed in isolation-reared rats. Indeed, com- zapine, quetiapine, and remoxipride (14,15). These findings parisons among different strains of rats indicate that both raise the possibility that the PCP-induced disruption of PPI effects are strain-dependent but appear in different strains may be a useful model for identifying compounds with atyp- (91–93). Thus, as with a variety of pharmacologic manipu- ical antipsychotic potential. Although this model lacks some of the impor- to exhibit a neuroleptic-reversible deficiency in PPI in com- tant characteristics of acute models, such as lack of an effect parison with group-reared controls (91,94). This effect of on PPI, it produces an enduring cognitive impairment that isolation rearing appears to be specific to development; simi- is highly relevant to schizophrenic symptomatology. Furthermore, as in the most common form of schizophrenia, the PPI deficits DEVELOPMENTAL MODELS are not evident before puberty but emerge at about that time (96). Converging evidence for an influence of isolation The best-characterized animal model in this class is that rearing on gating mechanisms in adulthood stem from the proposed by Lipska and Weinberger (86,87), which involves observation that the rat analogue of the P50 sensory gating neonatal excitotoxic lesions of the ventral hippocampus. Because these deficits in PPI and P50 gating are not such as increased spontaneous, amphetamine-induced, and associated with concomitant deficits in latent inhibition NMDA antagonist-induced locomotion. They also produce (95), which occurs only in acutely ill schizophrenic patients potentiated apomorphine-induced stereotypies, disruption (19), it would appear that the isolation-rearing model is of PPI, reduced cataleptic response to haloperidol, impaired more relevant to chronic than to acute schizophrenia. In working memory, and hypersensitivity to stressful stimuli. Thus, PPI deficits in isolation-reared rats may be a 1 (EAAT1) and glutamic acid decarboxylase (GAD67). To valuable paradigm that—like the apomorphine-induced the limited extent that they have been tested, dopamine disruption of PPI—is sensitive, but not specific, in its ability antagonists, including classic and atypical antipsychotic to identify compounds with atypical antipsychotic proper- drugs, ameliorate the behavioral abnormalities produced by ties. The potential advantage of the isolation-rearing model, neonatal ventral hippocampal lesions. It will be important as of other models involving developmental perturbations, in the future to examine the predictive power of this model is that it does not rely on the administration of a drug or for the identification of antipsychotic drugs more thor- the introduction of an artificial lesion to produce the behav- oughly with measures that are not sensitive to the effects ior of interest. When the behavior studied in the model is of antipsychotic drugs in sham-lesioned rats. Indeed, most of the animal models of nine, a nitric oxide synthase inhibitor that disrupts neuronal schizophrenia have relied on dopaminergic psychostimu- maturation (89), or the antimitotic agent methyazoxymeth- lants and have proved to be largely limited to the detection anol (54,90). These models produce morphologic changes of dopamine antagonists. The major message of the fact relevant to schizophrenia, such as altered neurogenesis and that clozapine is effective, even at doses that achieve low reduced cortical volume. They also produce some of the levels of dopamine receptor occupancy, is that new treat- behavioral characteristics associated with schizophrenia, ments can be identified for patients with schizophrenia, and such as stereotypy, cognitive impairments, and deficits in that these novel treatments may not involve dopamine an- PPI. As yet, the predictive validity of this model in terms tagonism. The isolation-rearing manipulation presumably of sensitivity to antipsychotic treatments remains to be de- produces a deficit in PPI by virtue of a substantial reorgani- termined. Chapter 50: Animal Models Relevant to Schizophrenia Disorders 697 Hence, such a model has the potential to identify completely receptor transduction) are associated with substrates that novel antipsychotic treatments simply because it does not regulate both PPI and latent inhibition, which are transmit- require the administration of a drug. In another approach, comparisons of several inbred strains of rats identified some strains that exhibit deficits in PPI (103). Because these strains did not exhibit GENETIC MODELS hearing impairments, the genetically determined deficit in PPI likely represents a deficit in sensorimotor gating pro- Genetic contributions to schizophrenia have been clearly cesses. Although the focus of consid- erable research, the application of linkage analyses to schizo- GeneticallyModified Animals phrenia has not generally proved successful, perhaps because schizophrenia does not represent a single phenotype.
In: Bernardi G super cialis 80mg with amex, Carpenter MB cheap 80 mg super cialis free shipping, Di Chiara G, et mocortical circuits: parallel substrates for motor, oculomotor, al. New York: Plenum Press, 1989: 'prefrontal' and 'limbic' functions. Amelioration of par- Annu Rev Neurosci 1986;9:357–381. New perspectives in basal forebrain orga- (STN) in MPTP treated green monkeys. Mov Disord 1990; nization of special relevance for neuropsychiatric disorders: the 5(suppl1):79. Neuronal activity in the MPTP model of 1937;60:424–436. Brain tory activity of neurons in pallidal-receiving areas of the monkey dopamine and the syndromes of Parkinson and Huntington. Changes in firing of pallidal neurons Nature Neurosci 2000;3:1301–1306. A quantitative analysis of pallidal J Neurosci 1999;19:599–609. Synaptic integration of func- tionally diverse pallidal information in the entopeduncular nu- Exp Brain Res 1991;86:623–632. Compensatory effects of potentiates NMDA receptor currents in neurons of the subtha- glutamatergic inputs to the substantia nigra pars compacta in lamic nucleus. Involvement of the subtha- lamic nucleus for the alleviation of 1-methyl-4-phenyl-1,2,3,6- lamic nucleus in glutamatergic compensatory mechanisms. Eur tetrahydropyridine (MPTP)-induced parkinsonism in the pri- J Neurosci 1999;11:2167–2170. Hemiparkin- kinsonism due to organophosphate pesticide intoxication: five sonism in monkeys after unilateral internal carotid artery infu- cases. Motor disturbance and brain functional imaging in 22. Thalamotomy for par- induced by high-frequency deep-brain stimulation. Proc Natl Acad Sci USA tions to sensorimotor cortex in the macaque monkey: use of 1983;80:4546–4550. Motor learning in activates the cortical motor system during alleviation of parkin- monkeys (Macaca fascicularis) with lesions in motor thalamus. Role of corticospinal motor projec- in southern Italy. Cerebral potentials related to voluntary actions: par- 51. Interconnec- messenger RNA in rat pallidum: comparison of the effects of tions and organization of pallidal and subthalamic nucleus neu- haloperidol, clozapine and combined haloperidol-scopolamine rons in the monkey. Activity of basal ganglia neurons during move- of thalamocortical activity after posteroventrolateral pallido- ment. Basal ganglia function and ments in basal ganglia disorders. Neurobehav Toxicol Teratol dysfunction revealed by PET activation studies. The effects of nanoli- tween movement and single cell discharge in the substantia nigra ter ejections of lidocaine into the pontomedullary reticular for- of the behaving monkey. Primate model of properties of identified output neurons of the rat substantia parkinsonism: selective lesion of nigrostriatal neurons by 1- nigra (pars compacta and pars reticulata): evidences for the exis- methyl-4-phenyl-1,2,3,6-tetrahydropyridine produces an extra- tence of branched neurons. A single-cell study adult mouse: evidence of compensatory plasticity in nigrostriatal of the axonal projections arising from the posterior intralaminar neurons. An autoradiographic study of effer- glia-thalamocortical relations in normal and parkinsonian ent connections of the globus pallidus in Macaca mulatta. Anatomic and physio- ral activity in spatial rather than joint coordinates. Functional brain imaging of move- tomy and thalamotomy using individual variations of anatomic ment disorders. Pallidotomy increases in a retrograde double-labelling study. Building action repertoires: memory and learning methyl-4-phenyl-1,2,3,6,-tetrahydropyridine (MPTP). Curr Opinion Neurobiol 1995;5: Neurosci Abstr 1985;11:1160. Abnormal influences of pas- matergic cells in the rat mesopontine tegmentum: light and sive limb movement on the activity of globus pallidus neurons electron microscopic anterograde tracing and immunohisto- in parkinsonian monkeys. J Neurol Neuro- tion and outcome following pallidotomy: support for multiple surg Psychiatry 1981;44:534–546. Subthalamotomy im- cally mapped body-part representations. J Neurophysiol 1991; proves MPTP-induced parkinsonism in monkeys. J Neuropathol medial prefrontal circuit through the primate basal ganglia.
The main cost drivers were found to be inpatient stays (elective and emergency) and GP visits discount super cialis 80 mg visa. TABLE 32 Mean health-care costs (annualised super cialis 80 mg with visa, in £) per patient during the control and intervention phase Phase, mean cost (SD) Health-care provision Intervention Control Difference in cost (£) ED attendances (discharged) 30. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals 65 provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising. Applications for commercial reproduction should be addressed to: NIHR Journals Library, National Institute for Health Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK. HEALTH ECONOMICS RESULTS TABLE 33 Mean total health-care costs (annualised, in £) per patient (overall and per risk group) during the control and intervention phase Phase, mean cost (SD) [n] Adjusted comparison Group Intervention Control Estimated (p-value) 95% CI Alla 1548. Including all primary and secondary care costs and after covariate adjustment, the total cost difference between the control and intervention phase shows an increase of £75. Cost-effectiveness analysis All costs were annualised to account for the difference in the duration of the control and intervention phases. Base-case analysis showed a small difference in total health-care costs between the control and intervention phases (see Table 25). This was mainly attributable to the relatively small implementation cost of PRISM per patient and the marginal cost increases per patient during the intervention phase. The clinical effectiveness analysis found an increase in the number of emergency admissions from 0. Therefore, no emergency admissions were avoided while an incremental cost of £0. The intervention is therefore less effective and more costly than the control and can hence be concluded to be dominated by the control. As a consequence, no ICERs were calculated as the PRISM tool cannot be considered cost-effective. Sensitivity analysis The parameter changes applied in the one-way sensitivity analysis are outlined in Table 34. The results appeared robust in the univariate sensitivity analysis and did not change significantly from base case. Based on the difference in number of emergency admissions between control and intervention phase, the intervention remained dominated by the control (routine practice) in all analyses. Covariate-adjusted incremental costs per patient incurred in the intervention phase (including PRISM implementation), ranged 66 NIHR Journals Library www. Considering the pooled uncertainty of all parameters, probabilistic sensitivity analysis showed a probability of the intervention being cost-effective of 21% if a willingness-to-pay threshold of £3666. Cost–utility analysis Utility scores (QALYs) were slightly lower in the intervention phase (0. After adjustment for covariate effects, the difference of –0. Considering the higher cost of the PRISM scoring tool and generally higher health-care cost in the intervention phase, the intervention is dominated by the control. No ICER was therefore generated for the cost per QALY gained. Probabilistic sensitivity analysis showed that the probability that the intervention is cost-effective at a willingness-to-pay threshold of £20,000 is 46% when all parameter uncertainty is considered. Cost–consequence analysis Table 35 summarises the results of the cost–consequence analysis. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals 67 provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising. Applications for commercial reproduction should be addressed to: NIHR Journals Library, National Institute for Health Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK. HEALTH ECONOMICS RESULTS TABLE 35 Clinical effectiveness and cost-effectiveness outcomes (adjusted where appropriate): cost–consequence analysis Phase Cost/health impact Intervention Control Difference p-value Annual costs (£) impact Implementation cost: total 25,349. Notes Values in brackets represent 95% CI unless indicated otherwise. Budget impact of the Predictive RIsk Stratification Model in the study area The annualised budget impact of PRISM per 100,000 population in the trial area during the intervention phase is detailed in Table 36. During the 1-year duration of the intervention phase, the total cost of primary and secondary care was £1. Taking into consideration the implementation costs of PRISM of £11,487 per 100,000 population, this results in an increased cost of £1. Furthermore, after adjustment for covariate effects, the rise in health-care costs that coincided with the PRISM scoring tool in the trial area and 1-year intervention phase gave an estimated increase in budgetary impact to a mean £7. Limitations of the health economic analysis There are several limitations associated with the economic analysis. The implementation cost for the PRISM scoring tool was costed according to the procedure and use as recorded in the trial. Any changes in routine use will result in costs to differ from the ones reported here. Hospital admissions in the SAIL database are coded as elective, emergency and other. No length of stay data were available for this study for elective inpatient stays. They were therefore costed according to the national average as reported in the NHS Reference Costs 2014/15,68 which will introduce bias.
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