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Biomedical subjects

James Marsh

Publications and source records attributed to James Marsh.

5 recordsLinked to original sources

Posttransplantation anemia in adult renal allograft recipients: prevalence and predictors.

BACKGROUND: Management of anemia is an important factor in the care of patients with chronic kidney disease as the anemic state can confer significant morbidity and mortality. Posttransplantation anemia (PTA) has received comparatively less attention in the literature, and the prevalence and predictors of PTA vary between different studies. The purpose of this study was to investigate a large posttransplant population from 3 centres in the UK to elucidate the point prevalence of PTA, its determinants and the use of erythropoiesis stimulating agents (ESA) in these patients. METHODS: All adult patients with functioning renal transplants and attending renal transplant outpatients at Guy's, King's College, or St. Helier Hospitals, London, as of 31/12/2004 who had a valid hemoglobin in the previous 3 months, and who were more than 3 months postengraftment, were identified. Patients' notes and electronic patient records were obtained and a detailed cross-sectional clinical and biochemical database was constructed. The data were analyzed for the point prevalence of PTA, the prevalence of ESA use and for determinants of hemoglobin. The WHO criteria were used to define anemia and all patients on treatment with an ESA was classified as anemic irrespective of hemoglobin. RESULTS: A total of 1,511 (947 male) patients were studied. Mean age was 48.1+/-13.7 years with no difference between the sexes. Mean time posttransplantation was 8.5+/-7.2 years and mean estimated MDRD GFR was 47.6+/-18.9 ml/min with a higher GFR in males (49.9+/-19.0 v 43.8+/-18.0 mL/min, P<0.0001). Mean hemoglobin in the studied population was 12.9+/-1.6 g/dl with a significantly higher level among males than females (mean 13.3+/-1.6 v 12.3+/-1.4 g/dl, P<0.0001). The prevalence of anemia was 45.6% with a prevalence of 44.1% among males and 48.1% amongst females. Severe anemia was present in 50 subjects (3.3% of the total cohort). One hundred and forty-five patients (9.6% of the entire cohort) were being treated with an ESA. Of these subjects, 41 did not meet WHO criteria for the definition of anemia. After multiple regression analyses, age, female sex, renal function and to a lesser extent serum ferritin and therapy with angiotensin converting enzyme inhibitors/angiotensin II receptor blockers (both negatively associated) were predictive of hemoglobin. CONCLUSIONS: The prevalence of anemia posttransplantation was high while comparatively few patients were being treated with erythropoiesis stimulating agents. The strongest predictors of hemoglobin in this cohort of patients were age, female sex and allograft function. Medical therapy with MMF and sirolimus was associated with a high prevalence of anemia but this was likely to be the result of poorer graft function in these subjects who mostly had chronic allograft nephropathy. A large interventional prospective study with valid control groups is now needed to assess the long-term contributions of clinical and biochemical factors of renal function and to elucidate the effects of therapy on outcome.

Adult↗

AA amyloidosis complicating hyperimmunoglobulinemia D with periodic fever syndrome: a report of two cases.

AA amyloidosis is the most serious potential complication of the inherited autoinflammatory syndromes and frequently results in end-stage renal failure. Although this complication is well recognized in familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome, and Muckle-Wells syndrome, there is only 1 previous published report of its occurrence in hyperimmunoglobulinemia D with periodic fever syndrome (HIDS). We report 2 further cases of patients with AA amyloidosis in HIDS, both of whom developed dialysis-dependent renal failure, and we describe the outcome of the first renal transplant in this setting.

Adult↗

Plasma alpha2-HS glycoprotein concentrations in patients with acute myocardial infarction quantified by a modified ELISA.

BACKGROUND: Human alpha2-HS glycoprotein (alpha2-HSG) is synthesized and secreted by the liver into circulation. Plasma concentrations of alpha2-HSG decrease significantly following infection, inflammation and malignancy. Since increased plasma concentrations of C-reactive protein are observed in patients with acute myocardial infarction (AMI), we hypothesized that plasma concentrations of alpha2-HSG would decrease during the initial phase of AMI and begin to increase in the recovery phase. METHODS: Twenty patients diagnosed with AMI were recruited for the study. A sensitive and specific ELISA was developed to assay alpha2-HSG concentrations in plasma. RESULTS: In AMI patients, plasma alpha2-HSG concentrations were decreased (281.3+/-25.8 mg/l, ranging from 132 to 489 mg/l on admission) compared to healthy individuals (312.3+/-9.9 mg/l, ranging from 210 to 450 mg/l) (P= 0.142). Interestingly, 40% of AMI patients demonstrated alpha2-HSG concentrations below 200 mg/l compared to none in the healthy control group. During the recovery period, alpha2-HSG concentrations begin to increase, with a mean+/-SEM of 290.1+/-22.1 mg/l. Regression analysis comparing plasma alpha2-HSG concentrations on admission to concentrations on discharge showed a significant positive correlation in matched-pair patient samples (P<0.01, r=0.45). CONCLUSIONS: We conclude that, in contrast to C-reactive protein, alpha2-HSG functions as a negative acute phase protein in AMI patients. Plasma alpha2-HSG concentrations start to decrease within a few hours after the onset of AMI and return to near normal concentrations during the recovery period (5-7 days after AMI).

Adult↗

A network architecture supporting consistent rich behavior in collaborative interactive applications.

Network architectures for collaborative virtual reality have traditionally been dominated by client-server and peer-to-peer approaches, with peer-to-peer strategies typically being favored where minimizing latency is a priority, and client-server where consistency is key. With increasingly sophisticated behavior models and the demand for better support for haptics, we argue that neither approach provides sufficient support for these scenarios and, thus, a hybrid architecture is required. We discuss the relative performance of different distribution strategies in the face of real network conditions and illustrate the problems they face. Finally, we present an architecture that successfully meets many of these challenges and demonstrate its use in a distributed virtual prototyping application which supports simultaneous collaboration for assembly, maintenance, and training applications utilizing haptics.

Communication↗