By A. Kaffu. Pomona College. 2018.
N Engl J M ed duction in rats with renal m ass reduction buy discount suhagra 100 mg on-line. Rees DD 100mg suhagra with amex, Palm er RM J, M oncada S: Role of endothelium -derived nitric enzym e inhibitor benazepril on the progression of chronic renal insuf- oxide in the regulation of blood pressure. Am J gression to end-stage renal failure in proteinuric, non-diabetic chronic Physiol 1991, 261:F1033–F1037. Giatras I, Lau J, Levey AS: Effect of angiotensin-converting enzym e the renal response to L-arginine in hum an kidney transplant recipients. Pohl he major issues in approaching patients with renal artery steno- sis relate to the role of renal artery stenosis in the management Tof hypertension, ie, “renovascular hypertension,” and to the potential for vascular compromise of renal function, ie, “ischemic nephropathy. M uch discussion has focused on the pathophysiology of renovascular hyper- tension, the renin angiotensin system, diagnostic tests to detect pre- sumed renovascular hypertension, and the relative merits of surgical renal revascularization (SR), percutaneous transluminal renal angio- plasty (PTRA), and drug therapy in managing patients with renal artery stenosis and hypertension. H emodynamically significant renal artery stenosis, when bilateral or affecting the artery to a solitary func- tioning kidney, can also lead to a reduction in kidney function (ischemic nephropathy). This untoward observation may be reversed by interventive maneuvers, eg, surgical renal revascularization, PTRA, or renal artery stenting. The syndrome of “ischemic renal disease” or “ischemic nephropathy” now looms as an important clinical condi- tion and has attracted the fascination of nephrologists, vascular sur- geons, and interventional cardiologists and radiologists. The detection of renal artery stenosis in a patient with hyperten- sion usually evokes the assum ption that the hypertension is due to the renal artery stenosis. H owever, renal artery stenosis is not synony- m ous with “renovascular hypertension. The vast m ajority of patients with ASO -RAS who have hypertension have essential hypertension, not renovascular hyperten- sion. These hypertensive patients with ASO -RAS are rarely cured of their hypertension by interventive procedures that either bypass or 3 3. Thus, it is critical to distinguish chronic subcapsular hematoma, and unilateral ureteral obstruction between the anatom ic presence of renal artery stenosis, in may also be associated with hypertension that is relieved when which a stenotic lesion is present but not necessarily causing the affected kidney is removed. These clinical analogues of the hypertension, and the syndrom e of renovascular hypertension experimental Page kidney reflect the syndrome of renovascular in which significant arterial stenosis is present and sufficient to hypertension (RVHT), but without main renal artery stenosis. In the exam ples of RVH T without m ain renal artery stenosis. FIGURE 3-1 CLASSIFICATION OF RENAL Classification of renal artery disease. Two m ain types of renal arterial lesions form the ARTERY DISEASE anatom ic basis for renal artery stenosis. Atherosclerotic renal artery disease (ASO -RAD) is the most common cause of renal artery disease, accounting for 60% to 80% of all renal artery lesions. The fibrous dysplasias are the other m ajor category of renal artery disease, Disease Incidence, %* and as a group account for 20% to 40% of renal artery lesions. Arterial aneurysm and arteriovenous m alform ation are rarer types of renal artery disease. Atherosclerosis 60–80 Fibrous dysplasia 20–40 Medial (30%) Perimedial (5%) Intimal (5%) *Percent of renal artery lesions. Atherosclerotic renal artery disease is typi- cally associated with atherosclerotic changes of the abdominal aorta (see panel B). ASO- RAD predominantly affects men and women in the fifth to seventh decades of life but is uncommon in women under the age of 50. Anatomically, the majority of these patients demonstrate atherosclerotic plaques located in the proximal third of the main renal artery. In the majority of cases (70% to 80% ), the obstructing lesion is an aortic plaque invad- ing the renal artery ostium (ostial lesion). Twenty to 30 percent of patients with ASO- RAD demonstrate atherosclerotic narrowing 1 to 3 cm beyond the takeoff of the renal artery (nonostial lesion). Nonostial lesions are technically more amenable to percuta- neous transluminal renal angioplasty (PTRA) than ostial ASO-RAD lesions, which are technically difficult to dilate and have a high A B restenosis rate after PTRA. Renal artery stenting has gained wide acceptance for ostial FIGURE 3-2 lesions. Endovascular intervention for nonos- Angiographic exam ples of atherosclerotic renal artery disease (ASO -RAD). A, Aortogram tial lesions includes both PTRA and stents.
The BZD ders including social anxiety disorder discount 100mg suhagra fast delivery, generalized anxiety and GABAA receptors form parts of the same macromolecu- disorder cheap 100 mg suhagra amex, PD, and PTSD. One of the multiple secondary lar complex, and although they constitute distinct binding effects of these agents involves potentiation of GABAergic sites, they are functionally coupled and regulate each other function. For example, in rats, the effective dose of phenel- in an allosteric manner (258). Central BZD-receptor ago- zine (15mg/kg) on the elevated plus maze administered nists potentiate and prolong the synaptic actions of the in- produces a more than twofold increase in whole-brain level hibitory neurotransmitter, GABA, by increasing the fre- GABA concentrations, whereas an ineffective dose of phe- quency of GABA-mediated chloride channel openings (258, nelzine (5. Microinjection of BZD-receptor agonists in limbic (267). Moreover, the N-acetylated metabolite of phenelzine, and brainstem regions such as the amygdala and the PAG N-2-acetylphenelzine, which potently inhibits monoamine exert antianxiety effects in animal models of anxiety and fear oxidase but does not change whole-brain GABA concentra- (260). Conversely, administration of BZD-receptor inverse tions, does not produce anxiolytic effects in the elevated agonists, such as -carboline-3-carboxylic acid ethylester, plus-maze test (267). Transgenic mouse studies have identified behavioral roles for specific GABAA-receptor subunits. The anxiolytic action of diazepam appears absent in mice with 2 subunit point Effects of Stress on Benzodiazepine-GABAA mutations, but it is present in mice with 1 or 3 subunit Receptors point mutations (264,265). These data suggest that the an- xiolytic effect of BZD agonists is at least partly mediated BZD- and GABA-receptor function can be altered by expo- by the GABA -receptor subunit, which is largely ex- sure to stress in some brain regions. In experimental animals A 2 pressed in the limbic system, but not by the subunit, exposed to inescapable stress in the form of cold swim or 3 which is predominately expressed in the reticular activating foot shock, the BZD-receptor binding decreases in the fron- system, or the subunit, which is implicated in mediating tal cortex, with less consistent reductions occurring in the 1 the sedative, amnestic, and anticonvulsive effects of BZDs hippocampus and hypothalamus, but no changes in the oc- (265,266). These findings hold clear implications for inves- cipital cortex, striatum, midbrain, thalamus, cerebellum, or tigations of the pathophysiology of anxiety disorders and for pons (268). Chronic stress in the form of repeated foot the development of anxioselective BZD-receptor agonists. The neurosteroid, allopregnenolone, ex- in BZD-receptor binding were associated with deficits in erts antianxiety effects in conflict paradigms that serve as maze escape behaviors that may have reflected alterations putative animal models of anxiety. The anticonflict effects in mnemonic processing (269,270). Some of these stress of allopregnenolone are reversed by either isopropylbicyclo- effects may be mediated by glucocorticoids, because chronic phosphate, which binds at the picrotoxinin site on the exposure to stress levels of CORT alters mRNA levels of GABAA receptors, or RO15-4513 (ethyl-8-azido-5,6-dihy- multiple GABAA-receptor subunits (271). Consistent with dro-5-methyl-6-oxo-4H-imidazo[1,5- ]-[1,4]benzodiaze- the effects of chronic stress on BZD-receptor expression, pine-3-carboxylate), a BZD-receptor inverse agonist that the Maudsley 'genetically fearful' rat strain shows decreased inhibits GABAA-activated chloride flux in neuronal mem- BZD-receptor density relative to other rats in several brain branes. In contrast, administration of the BZD-receptor an- structures including the hippocampus (272). Allopregnenolone may thus exert reduced BZD-receptor sites in the LC, the NTS, the frontal anxiolytic-like effects by stimulating the chloride channel cortex, and the CE and the LA of the amygdala, and reduced in GABAA receptors by binding at the picrotoxinin site or mRNA levels for the 2 subunit of the GABAA-receptor at a site specific for RO15-4513. The The antianxiety effects of antidepressant drugs with pri- extent to which these developmental responses to early-life Chapter 63: Neurobiological Basis of Anxiety Disorders 917 stress may alter the expression of fear and anxiety in adult- global reduction in BZD site binding in seven study subjects hood remains unclear. Anxiety Disorders found no differences in the Bmax, Kd or bound/free values The central BZD receptor has been implicated in anxiety for [11C]flumazenil in any brain region in ten unmedicated disorders on the basis of the anxiolytic and anxiogenic prop- PD study subjects relative to healthy controls (283). Hypotheses advanced regarding the role Acute stress increases DA release and turnover in multiple of GABAA-BZD–receptor function in anxiety disorders brain areas. The dopaminergic projections to the mPFC have proposed either that changes in the GABAA-BZD mac- appear particularly sensitive to stress, because brief or low- romolecular complex conformation or that alterations in the concentration or properties of an endogenous ligand intensity stressors (e. However, these hypotheses have not been conclu- absence of corresponding changes in other mesotelenceph- sively tested by in vivo or postmortem studies of anxiety- alic dopaminergic projections (284). In con- attacks and increases anticipatory anxiety in some subjects trast, stress of greater intensity or longer duration addition- with PD, but not in healthy controls. In addition, the sensi- ally enhances DA release and metabolism in other areas as tivity to the effects of diazepam on saccadic eye movement well (285). The regional sensitivity to stress appears to fol- velocity is abnormally reduced in PD, a finding implying low a pattern in which dopaminergic projections to the that the functional sensitivity of the GABA -BZD supramo- mPFC are more sensitive to stress than the mesoaccumbens A lecular complex is attenuated in brainstem regions control- and nigrostriatal projections, and the mesoaccumbens dopa- ling saccadic eye movements (275). Subjects with PD also minergic projections are more sensitive to stress than the show abnormally reduced sensitivity to the suppressant ef- nigrostriatal projections (284). Pa- tal (278–280), temporal (278,279), and occipital (278) cor- tients with PD were also shown to have a greater growth tices in subjects with PD relative to control subjects. However, Eriksson absence of medication-free PD study subjects and of healthy et al. A tween CSF HVA and anxiety severity or panic attack fre- SPECT-iomazenil study that quantitated BZD-receptor quency (288).
In the event that there was any concern for the health and well-being of our PPI members generic 100 mg suhagra otc, we also had a GP team member (SM) who could provide some initial advice discount suhagra 100mg without a prescription, with the proviso that they then contact their own GP. Neither Christine Hoy nor Stewart Mercer was called on to act in these capacities. We used the NIHR cost calculator for public involvement, in conjunction with advice from the ALLIANCE about appropriate levels and methods of remuneration for patient/public involvement, to ensure that we had the funds to support this. Project management Margaret Maxwell was responsible for overall project delivery and worked on a day-to-day basis as required with the project manager (CH) and the two part-time research assistants (RAs). Carina Hibberd was project manager and supervised the two part-time RAs on a day-to-day basis and conducted fieldwork alongside the RAs as required, as well as being responsible for adapting and delivering the training to nurses. There were weekly meetings between Margaret Maxwell, Carina Hibberd and the RAs to report on study progress and timelines, and to deal with any immediate problems. Nadine Dougall and Rebekah Pratt also attended these meetings, as required, to ensure that preparation for data collection and subsequent data 12 NIHR Journals Library www. Video and telephone conferencing was available to minimise time and travel when attendance was required. Formal PMG meetings were held with all co-applicants and other members of our PMG, including our patient/carer representatives. These included a feedback report on study progress and discussion of any problems/issues arising. An independent SSC was established with four members: Professor Brian McKinstry (University of Edinburgh, Professor of Primary Care and practising GP) to chair the committee; Dr Ruth Jepson (University of Edinburgh, Senior Scientific Advisor, Scottish Collaboration for Public Health Research and Policy); Dr Dorothy Horsburgh (Edinburgh Napier University, Senior Lecturer, nurse and specialist in LTCs); and one PPI member. Dr Horsburgh retired during the study and was replaced by Dr Debbie Baldie of Queen Margaret University. Observers such as a sponsor representative, a representative of the Scottish Primary Care Research Network (SPCRN) and any members of the research team could be invited at the request of the chairperson. Formal SSC meetings (n = 4) were held in Edinburgh and consisted of a feedback presentation and supporting documentation, including any ethics amendments and their outcomes, interim reports to the funder (NIHR) and minutes of the PMG. Analytical framework Quantitative analysis The primary outcome of the pilot trial was to determine recruitment and retention rates of PNs, and the recruitment of patients and data completion for a future cluster RCT. We also wanted to establish which nurse- and patient-level measures should constitute primary and secondary outcomes for a future cluster RCT and, hopefully, use this knowledge to determine sample size for a future trial. The study combined data collection for nurses and patients as two separate units of analysis. One of the criteria for continuation to a full-scale trial would be to determine if the number of nurses required for a cluster RCT was feasible and within reasonable cost boundaries. Such a design would also need to be sufficiently powered at the patient level, thereby testing the impact of the PCAM tool on both nurse behaviour and patient outcomes. The characteristics of the nurses and patient groups and their related outcome measures were summarised using descriptive analysis. The related outcome measures were summarised using descriptive analysis together with estimates of precision, and any relevant change scores. Some modifications were made to the statistical analysis plan that was created at the time of requesting funding for the study. Since then, there has been a shift in expert guidance advising against all formal significance testing for pilot and feasibility study outcome measures, as these are not powered to detect statistical significance. Therefore, formal significance testing was omitted, as was the use of the multiple regression modelling approach. The focus of the analysis centred on the recruitment, data completion and attrition rates, and making use of descriptive analysis to summarise the data. The PEI and CARE measures were analysed at the nurse level and the 12-item General Health Questionnaire (GHQ-12), SF-12 and WEMWBS were analysed at the patient level. Both units of analysis were summarised between randomisation groups, using means and standard deviations, or medians and interquartile ranges, together with change scores estimated with their 95% confidence intervals (CIs). The number of practices recruited and the number of nurses recruited were less than planned, and this also ruled against the use of formal regression models to explore the influence of covariates on outcome measures.
Thus generic 100mg suhagra amex, it is reasonable to predict that patients will have a wide variety Other Manifestations of dysfunctions extending well beyond the classic motor In addition to these neurologic signs and symptoms discount 100 mg suhagra, PD disabilities associated with the disease. Many PD patients also have signs of auto- of cognitive and psychiatric dysfunctions. Most common is nomic failure, including orthostatic hypertension, constipa- dementia and depression. However, hallucinations, delu- tion, urinary hesitancy, and impotence in men (90,107, sions, irritability, apathy, and anxiety also have been re- 133). Here we will comment on the most prevalent of these symptoms. Dementia is now recognized as one of the cardinal non- PATHOLOGY motor manifestations of PD. It is a major cause of disability, Neuron Loss and, unlike the motor manifestations, there currently is no effective symptomatic treatment. Aarsland and co-workers A hallmark pathologic feature of PD, and essential for its (2) identified in dementia in 28% of PD patients. The prev- pathologic diagnosis, is loss of DA neurons of the substantia alence depends on age; in a study of PD patients over the nigra pars compacta (SNpc). At the time of death, even age of 85by Mayeux et al. We Years ago, there was debate about whether depression is have discussed the basis for the need for extensive loss of DA a primary manifestation of PD or a reaction to having a neurons before the emergence of gross neurologic deficits in chronic neurologic illness. There is now little question that the previous edition of this series (5) and elsewhere (164, it is a primary manifestation. Briefly, our conception is as follows: As the terminals have found that 47% of PD patients show evidence of of DA neurons degenerate, there is a reduction in high- depression, and some have found an even higher incidence affinity DA uptake. Moreover, Aarsland and colleagues (2) report that dundancy in DA terminals and DA receptors, appears to major depression is much more common among PD pa- permit striatal function to continue without disruption or tients who also have signs of dementia (22%) than those active compensation during early phases of the neurodegen- who did not (2%). The depression, however, is not related erative process. After somewhat larger lesions, the remaining to the severity of motor signs; indeed, many patients are DA terminals appear to increase the amount of transmitter depressed prior to the onset of frank neurologic dysfunction. This Moreover, the depression is often greater than that seen in seems to be due at least in part to a net increase in the individuals with comparably debilitating motor dysfunction amount of DA released in response to terminal depolariza- due to other disorders. Once released, a portion of the DA appears of the nucleus basalis of Meynert, and this may be responsi- to diffuse out of the synapse and into the extracellular space, ble, at least in part, in some cases, for dementia (159). We hypothesize that these Lewy Bodies events permit the SNpc to continue to exert dopaminergic control over striatal cell function as long as some minimal Another pathologic hallmark of PD is the Lewy body, an number of DA terminals remain. However, the increased eosinophilic inclusion identified within neurons. On histo- synthesis and release of DA may increase reactive metabo- logic stains, Lewy bodies have an eosinophilic core, and a lites formed from DA and thus contribute to the progression surrounding pale halo. They are usually rounded, although of the disease (see below). They usually are observed within falls below the level required for rapid compensation or the cell soma, but also can be seen in neurites or free in the when the system is subjected to certain pharmacologic, envi- extracellular space. Lewy bodies are commonly observed in ronmental, or physiologic challenges. These can subside if the brain regions showing the most neuron loss in PD, additional, slowly developing compensations, such as the including SN, locus coeruleus, the dorsal motor nucleus of synthesis and insertion of additional DA receptors, the in- the vagus, and the nucleus basalis of Meynert, but they are duction of typrosine hydroxylase (TH) synthesis, sprouting, also observed in neocortex, diencephalon, spinal cord, and or regeneration, occur at a more rapid rate than does the even peripheral autonomic ganglia (50). This has been observed to On ultrastructural analyses, Lewy bodies consist of an be the case in animal models, wherein recovery often occurs electron dense granular core and a peripheral halo consisting after the abrupt loss of even 90% of striatal DA, as occurs of radially oriented filaments 7 to 8 nm in width (28). The filaments resemble neurofilaments, and can be immuno- in most animal models. In patients, however, where the stained with antisera to neurofilament proteins (53), includ- degenerative process is typically progressive, such recovery ing the NF-L, -M, and -H forms (67). Immunostaining can would not be expected to occur spontaneously. However, be achieved with antibodies that recognize phosphorylated an important implication of the ability of brain to compen- as well as nonphosphorylated epitopes (13,40). The cellular sate for partial loss of DA neurons in these ways is that once kinases responsible for the phosphorylation are not known.
9 of 10 - Review by A. Kaffu
Votes: 333 votes
Total customer reviews: 333