By N. Tuwas. Voorhees College.
Lithotripsy or surgery may be neces- Ox sary but do not alter the progression of nephrocalcinosis [12 buy tadacip 20 mg free shipping,13] discount tadacip 20mg otc. Ox H em odialysis is superior to peritoneal dialysis in its ability to rem ove oxalate, but neither one is able to m aintain a rate of oxalate rem oval sufficient to keep up with the production rate in Ox patients with PH 1. O nce end-stage renal disease develops, hem o- dialysis does not prevent the progression of system ic oxalosis. In som e patients, renal transplantation accom panied by an aggressive E program of m anagem ent has been followed by a good outcom e for years. H owever, oxalosis often recurs in the transplanted kid- ney, particularly if any degree of renal insufficiency develops for FIGURE 11-11 (Continued) any reason. In recent years, liver transplantation has been used and fifth year (C), following renal transplantation. Deposition of with success, with or without renal transplantation, and offers the oxalate crystals became progressively more severe with time, and the prospect of definitive cure. Results of liver transplantation are best kidney failed after 5 years. Panel D illustrates a higher-power magni- in patients who have not yet developed significant renal insufficien- fication, without polarization, of the biopsy at 5 years, showing a cy. Pure dialysis because of the higher clearance rates for uric acid. Frequent uric acid stones occur in patients with hyperuricosuria, particularly hem odialysis, even m ultiple tim es per day, m ay be necessary to pre- when the urine is acidic. Thus, therapy involves both allopurinol and vent extrem e hyperuricem ia and facilitate recovery of renal func- alkalinization with potassium alkali salts. A m odification of continuous arteriovenous hem odialysis has motes calcium oxalate stone formation. In these patients, calcium recently been reported to be effective in m anagem ent of these nephrolithiasis can be prevented by therapy with allopurinol. As a specific entity with intrarenal Acute uric acid nephropathy occurs m ost often in the setting of tophi, gouty nephropathy appears to have becom e uncom m on. It brisk cell lysis from cytotoxic therapy or radiation for m yeloprolif- appears clear that long-standing hyperuricemia alone is not sufficient erative or lym phoproliferative disorders or other tum ors highly to cause this condition in m ost patients, and that renal failure in responsive to therapy. Uric acid nephropathy can uncom m only patients with hyperuricemia or gout is almost always accompanied occur spontaneously in m alignancies or other states of high uric by other predisposing conditions, particularly hypertension or expo- acid production. Exam ples are infants with the Lesch-N yhan syn- sure to lead. It is characterized by recurrent gout, and, rarely, adults with gout who becom e volum e-contracted and often occurring in youth and even childhood; hyperuricemia; and whose urine is concentrated and acidic. Histopathology reveals interstitial inflammation and intratubular obstruction by crystals of uric acid in the setting of an fibrosis, almost always without evidence of urate crystal deposition, acute overwhelm ing load of uric acid, particularly in acidic urine. In contrast to gouty recent years, the widespread use of an effective prophylactic regimen nephropathy, hypertension usually is absent until renal failure is for chem otherapy has m ade acute uric acid nephropathy m uch less advanced. The hyperuricemia appears to reflect decreased renal com m on. This regim en includes preparation of the patient with excretion of urate rather than overproduction of urate. Although high-dose allopurinol, volum e-expanding the patient to m aintain a hyperuricemia precedes and is disproportionate to any degree of dilute urine, and alkaline diuresis. In patients whose tum or lysis renal failure, the role, if any, that uric acid plays in the pathogenesis leads to hyperphosphatem ia, however, it is im portant to discontinue of the renal failure remains unclear. These is no consensus among urinary alkalinization or else calcium phosphate precipitation m ay authors regarding the potential value of allopurinol in this disease. O ccasionally, patients will develop renal failure despite these The inheritance follows an autosomal dominant pattern, but, beyond m easures. In such patients, hem odialysis is preferable to peritoneal this, the genetics of the disease are not understood [18,19]. H ebert SC: Extracellular calcium -sensing receptor: im plications for 11. Scheinm an SJ: X-linked hypercalciuric nephrolithiasis: clinical syn- calcium and m agnesium handling in the kidney. Kidney Int 1996, drom es and chloride channel m utations. Edited by Scriver CR, et (polyvalent) cation-sensing receptor in kidney. Coe FL, Parks JH , Asplin JR: The pathogenesis and treatm ent of Kidney Int 1992, 42:1408–1411. Buckalew VM : N ephrolithiasis in renal tubular acidosis. J Urol 1989, lysis syndrom e in patients with acute leukem ia. Reiter L, Brown M A, Edm onds J: Fam ilial hyperuricem ic nephropathy.
These fibrils showed green birefringence when they To provide clues about the normal function of hunt- were stained with Congo red and viewed by polarized light ingtin and about HD pathogenesis tadacip 20mg without prescription, an intensive effort has microscopy cheap tadacip 20mg, consistent with the presence of sheets. Aggre- been devoted to finding proteins that interact with hunt- gation did not occur when the polyglutamine repeat was of ingtin. Interactors of particular interest include HIP1, normal length. In addition, aggregation only occurred when HAP1, GAPDH, and SH3GL3 (64). Some of these proteins a huntingtin fragment with an expansion of typical length are directly or indirectly associated with microtubule motor was first cleaved from the carrier protein to which it was proteins and intracellular vesicles, findings suggesting a role fused during synthesis for the assay. The implication, consis- for huntingtin in cytoskeletal function or vesicular trans- tent with cell and mouse models described later, is that port. The interaction of huntingtin and other proteins con- generation of a proteolytic fragment of HD may be an im- taining glutamine repeats with the metabolic enzyme portant step in HD pathogenesis. In fact, consensus cleavage GAPDH is of potential significance, given the possible role sites for caspase-3 (also termed apopain or CPP32) exist at of GAPDH in apoptosis (65). Huntingtin also interacts approximately position 513 and 530 of huntingtin, and with the nuclear co-repressor protein, and the strength of huntingtin can be cleaved by purified caspase-3, caspase-6, the interaction correlates to the length of the huntingtin and caspase-8. This interaction suggests that hunt- ingtin may have some role in transcriptional regulation, al- Cell Models though relatively little huntingtin is detected in the nucleus of normal cells under most conditions. Research into the pathogenesis of HD has been greatly facil- itated by the development of cell models. In the first, huntingtin is introduced into Polyglutamine Biochemistry cells through transient transfection; in the other, cell lines Many proteins contain stretches of polyglutamine, and such are engineered that stably express huntingtin (77–80). In tracts are more common than repeats of other amino acids general, short truncations of huntingtin containing the ex- (67). However, the normal function of glutamine repeats panded polyglutamine appear to be much more toxic than remains unknown. Proteins containing glutamine repeats full-length huntingtin and more liable to aggregation often appear to have a role in the regulation of development (81–83). However, aggregate formation and cellular toxic- and neurogenesis, and certain proteins with glutamine re- ity can be disassociated, a finding suggesting that cell toxic- peats are transcription factors (68). Glutamine-rich regions ity is not related in a simple way to aggregation (79,84, may function as factor interaction domains in transcription 85). Elimination of caspase cleavages sites may reduce the factors, but it is unclear whether glutamine repeats serve toxicity of mutant huntingtin (9,73–76). The lengths of glutamine not correspond to all characteristics of apoptosis, but it can repeats tend to vary considerably in homologous genes from be decreased or blocked in several models with caspase in- different species; mouse huntingtin has only seven consecu- hibitors (79,84). Transfection of One hypothesis for the role of glutamine repeats in primary neurons with constructs incorporating a nuclear human disease is based on the 'polar zipper' model pro- export signal diminished toxicity, whereas the addition of posed by Perutz (69). He suggested that two antiparallel nuclear localization signals appeared to enhance toxicity strands of polyglutamine can be linked together by hydro- (77,79) However, other studies suggested that both the nu- gen bonds between their main chain and side chain amides, cleus and the cytoplasm can be the site of pathogenesis (86). Circular dichroism, electron micro- Transgenic Mouse Models scopic and x-ray defraction studies of synthetic peptides, and an engineered protein provide in vitro evidence support- Transgenic animal models have provided some of the most ing the formation of strands and possibly sheets by striking evidence for the gain-of-function hypothesis of HD glutamine repeats. Alternatively, it has been suggested that pathogenesis. The first animal model of HD was con- the covalent modification of glutamines by an isopeptide structed using exon 1of huntingtin with a very long ex- linkage to lysine by the enzyme transglutaminase could also panded repeat (87). These animals developed progressive lead to an insoluble precipitate of proteins containing long neurologic deficits strikingly similar to those of HD, includ- stretches of glutamine (70). However, unlike patients filter assay was used to demonstrate that a short truncation with HD, neuronal cell loss is not prominent. These mice Chapter 125: Huntington Disease 1825 also developed intranuclear inclusions containing the trun- Invertebrate Models cated huntingtin transgene product, but not the endoge- Invertebrate models offer the potential of using powerful nous huntingtin protein (48). The intranuclear inclusions genetic techniques to search for genetic factors that enhance are present at the time, and perhaps before, the animals or suppress an experimentally induced phenotype. Several have neurologic signs or brain or body weight loss. The Drosophila models of polyglutamine-induced neurodegen- intranuclear inclusions are clearly distinct from the nucleo- eration have been generated (95–97), with many of the lus, and no membrane separates them from the rest of the same features of neuronal degeneration observed in mam- nucleus. Genetics screens have Several other HD mouse models have been constructed. A transgene consist- ing of a full-length huntingtin cDNA driven by the CMV A MODEL OF POLYGLUTAMINE promoter resulted in a line of mice with a rather different PATHOGENESIS phenotype, characterized by early weight gain and hyperac- tivity followed later by hypoactivity. These mice have both A model for HD pathogenesis is depicted in Figure 125.
Applications for commercial reproduction should be addressed to: NIHR Journals Library generic 20 mg tadacip amex, National Institute for Health Research buy generic tadacip 20 mg, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK. STUDY D: NURSE AND PATIENT PERCEPTIONS OF USING THE PATIENT CENTRED ASSESSMENT METHOD opportunity to support patients in relation to those concerns. And to look at them as two separate issues is not the way forward, you have to look at it as a holistic. If you can sort that out or help them, you know, even to help them manage their own needs and give them some kind of direction, that has a huge impact on their health. Nurse interview, participant 745 In addition, the nurse participants described times when the PCAM identified needs that the nurse could not address, even though they make onwards referrals. However, the participants described the value in knowing information about the patient that might influence the care they provided to the patient, by being sensitive to the context of that individual and their challenges. The nurse participants perceived this to be beneficial for both the patient and the nurse, in relation to both the quality of the relationship and the quality of the care provided. Signposting As part of its participation in the project, each practice was given a locally relevant collection of resources to which they could direct patients in response to any concerns raised by the various PCAM topic areas. The resource pack provided by the research team was very well received by the nurse participants. Some of the participants knew their local agencies and resources well, and did not find that the pack offered new information, although the convenience of it being provided in a folder was appreciated. Some nurse participants had not known of the local resources provided in the folder and were very pleased to have that information made available to them. Some participants expressed concern that they were unlikely to have the time and capacity to update the information following the conclusion of the project. Nurse interview, participant 745 58 NIHR Journals Library www. Nurse interview, participant 41 Participants also talked about copying and sharing the resource pack across the practice, and with colleagues who were not part of the research, as it was found to be of benefit for other staff to also be able to access: It was very easy. We were just saying that it would be good to copy it and let other staff in the practice use it too. Nurse interview, participant 178 Overall, there was a sense that the nurses found the resource pack very useful and had been active in signposting patients to various supports. This seemed to be accompanied by an approach of helping patients to access support for themselves and to address what their own priorities were, rather than focusing on fixing clinical issues: For patients to take the responsibility of looking after themselves with support from us and the better we can support them then hopefully the easier they will find it to take on the responsibility for their own health. Nurse interview, participant 745 Intended future use of the Patient Centred Assessment Method Participants were asked to reflect on their intentions around integrating PCAM-based consultations into their ongoing practice, beyond the course of the research project. 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 59 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. STUDY D: NURSE AND PATIENT PERCEPTIONS OF USING THE PATIENT CENTRED ASSESSMENT METHOD No participant in their feedback stated that they were opposed to using the PCAM in the future or made any comments indicating that they would be avoiding using the PCAM. Long-term adoption of the PCAM appears likely for some of the nurse participants in this research, beyond the research project itself. Conclusion The PCAM implementation did not have a negative or obstructive impact on the consultation. There was some indication that a small number of patients may have been aware of more discussion about their lives and their broader concerns. The PCAM training was acceptable, but required a multifaceted approach to training that integrated key information/knowledge, role playing and opportunities to apply the training to real consultations. Future training delivery will require the incorporation of these different aspects, and in a way that is flexible with nurse availability and workload. Overall, it appears that the PCAM was fairly easily integrated into consultation, although some participants reflected that the process of integration took some time and support, which will need to be taken into account in future training and support. The nurse participants perceived this to be beneficial for both the patient and the nurse, in relation to both the quality of the relationship and the quality of the care provided. Resource packs were seen as integral to using the PCAM, and practices engaged with these resources, often to the extent of taking ownership of their continuing development. However, for some practices, this could be seen as a future problem (how to keep these resources up to date) that could have an impact on their use of the PCAM. Long-term adoption of the PCAM was seen as feasible and possible by some nurses, which indicates overall potential for the acceptability and feasibility of the PCAM for use in primary care nurse-led consultations. The data used for the overall evaluation comprised: l contributions from study A focus groups with practices and patients on the acceptability and feasibility of the use of the PCAM, and any early reflections on barriers to using the PCAM in PN consultations l researcher field notes of meetings and discussions with staff l any comments to the research team or reported by practice staff from patients during implementation l data from study D, the final interviews with practice staff and patients l data from open-ended questions on staff and patient questionnaires collected as part of study B. The methods for studies A, B and D have been reported elsewhere. The collection of study field notes was seen as a fundamental part of the process evaluation and was ongoing throughout the study. Each study researcher kept their own logbook of visits and contacts with practices and any reported incidents/ problems, actions or comments associated with the study. The two researchers (EC and PA) had the most contact with practices, and each had more of a relationship with particular practices, thereby building rapport with practice staff and facilitating catch-up telephone or e-mail conversations between practice visits. However, this relationship was not exclusive to a single researcher and, therefore, all researchers, including Carina Hibberd, had some familiarity with all practices.
Reading discount tadacip 20 mg on-line, math- figure can probably be considered the upper limit for LD ematics buy 20mg tadacip overnight delivery, and writing comprise many processing skills, giving prevalence estimates based on ability/achievement discrep- rise to subtypes with different underlying mechanisms. Several researchers have questioned the conceptual and C. Keith Conners: Behavioral Neurology Department, Durham, North empiric basis for the use of ability/achievement discrepan- Carolina. Schulte: Department of Psychology, North Carolina State Uni- cies in the diagnosis of LDs, as well as current operationali- versity, Raleigh, North Carolina. Reasons for concern on 598 Neuropsychopharmacology: The Fifth Generation of Progress the use of ability/achievement discrepancies are (a) findings each are found, whereas in LDs alone, only symptoms of that the cognitive profiles of children with low achievement LD, not those of ADHD, are present, and vice versa (14). Alternate proposals for identification include simply using a low achievement criterion (e. In general, these alternate classification system will eventually be replaced by one that procedures are likely to raise prevalence rates. Vellutino and his colleagues used daily tutoring as a 'first The greatest progress in specifying the cognitive and cut' diagnostic criterion to distinguish between children neuropsychological dysfunctions underlying LDs has oc- who had reading difficulties caused by cognitive deficits and curred in reading. Numerous investigations using longitudi- those whose deficits were the result of poor instruction, they nal, intervention, genetic, and neuroimaging methods have found that two thirds of their sample scored within the produced strong and converging evidence that deficits in average range in reading (thirtieth percentile and higher) phonologic processing are the proximal cause of reading after one semester of one-to-one tutoring (12). This rela- difficulties in a large proportion of children with RDs (see tively stringent criterion for establishing an 'adequate edu- refs. Deficits in phonologic process- cational environment' resulted in a drop in the prevalence ing also appear to affect spelling, written expression, and rate of reading disorders (RDs) from 9% to 3%. Clearly, Although conceptualizations of phonologic processing and the definition of caseness in these studies has implications its components vary, within the Wagner and Torgesen for how phenotypes are characterized in genetic and neuro- model of phonologic processing, it consists of three related biological investigations. The use of the more conservative abilities: phonologic awareness, phonologic memory, and methods of case definition are clearly more costly for select- rapid naming (18,19). Phonologic awareness refers to the ing subjects, but they may prove more valid and useful in understanding that words can be broken down into pho- finding biological markers of LD. Phonemes are the smallest sound unit that changes the meaning of a word (e. Phonologic awareness is a critical ability in learning to read because it allows beginning readers to Many psychiatric and medical conditions include LD as an link letters and letter combinations in text to sound strings associated deficit. The most common childhood condition in oral language (20). Knowledge of these links allows read- comorbid with LD is ADHD. Estimates of comorbidity ers to discover the regularities in written text so written range from 20% to 90%, with the lower figures appearing words can be rapidly translated into their spoken equiva- in epidemiologic samples and the higher figures appearing lents. Such recoding allows the reader to access the semantic in clinically referred samples. The high degree of overlap in code (or meaning) for the letter string. The repeated pairing clinical samples suggests that common mechanisms may be of the visual letter string and its spoken equivalent is thought at work in the neurologic basis for both disorders. LDs eventually to allow the reader to develop direct visual word were once considered a necessary criterion for minimal brain recognition strategies that bypass the phonologic code (10, dysfunction. When children have additional interventions targeted toward increasing lan- difficulty with phonologic coding, reading acquisition is im- guage and reading fluency. Difficulties in verbal short-term memory are also example, Berninger et al. Geary proposed that there are three subtypes of (20). MDs, with corresponding deficits in semantic memory, pro- Rapid naming is the ability to access phonologic informa- cedural knowledge of mathematics, and visuospatial pro- tion that is stored in long-term memory rapidly. Such tasks are thought to tap many of the same cognitive processes required in skilled reading, such It has been known for decades that LDs run in families. There is debate about fluences on RD and MD (Table 44. The genetic studies whether the difficulty with rapid naming tasks observed in also confirm the heterogeneity of the phenotype, with both many children with RDs is a reflection of a core deficit in orthographic and phonologic traits implicated but not hav- phonologic processing or whether it represents a deficit in ing identical sources of genetic influence. A genetic link a second set of processes that impairs reading. If this is the between RD and MD was confirmed in several studies. A case, there may be 'double-deficit' readers who are im- strong link of Tourette syndrome, ADHD, and LD has paired in both phonologic and rapid naming processes (23).