David W. Johnson

Bio: David W. Johnson is an academic researcher from University of Queensland. The author has contributed to research in topics: Peritoneal dialysis & Kidney disease. The author has an hindex of 160, co-authored 2714 publications receiving 140778 citations. Previous affiliations of David W. Johnson include Minnesota Department of Transportation & Open University.

Recent Peritonitis Associates with Mortality among Patients Treated with Peritoneal Dialysis

Abstract: Peritonitis is a major complication of peritoneal dialysis, but the relationship between peritonitis and mortality among these patients is not well understood. In this case-crossover study, we included the 1316 patients who received peritoneal dialysis in Australia and New Zealand from May 2004 through December 2009 and either died on peritoneal dialysis or within 30 days of transfer to hemodialysis. Each patient served as his or her own control. The mean age was 70 years, and the mean time receiving peritoneal dialysis was 3 years. In total, there were 1446 reported episodes of peritonitis with 27% of patients having ≥2 episodes. Compared with the rest of the year, there were significantly increased odds of peritonitis during the 120 days before death, although the magnitude of this association was much greater during the 30 days before death. Compared with a 30-day window 6 months before death, the odds for peritonitis was six-fold higher during the 30 days immediately before death (odds ratio, 6.2; 95% confidence interval, 4.4–8.7). In conclusion, peritonitis significantly associates with mortality in peritoneal dialysis patients. The increased odds extend up to 120 days after an episode of peritonitis but the magnitude is greater during the initial 30 days.

Obesity Is Associated with Worse Peritoneal Dialysis Outcomes in the Australia and New Zealand Patient Populations

Abstract: Although obesity is associated with increased risks of morbidity and death in the general population, a number of studies of patients undergoing hemodialysis have demonstrated that increasing body mass index (BMI) is correlated with decreased mortality risk. Whether this association holds true among patients treated with peritoneal dialysis (PD) has been less well studied. The aim of this investigation was to examine the association between BMI and outcomes among new PD patients in a large cohort, with long-term follow-up monitoring. Using data from the Australia and New Zealand Dialysis and Transplant Registry, an analysis of all new adult patients (n = 9679) who underwent an episode of PD treatment in Australia or New Zealand between April 1, 1991, and March 31, 2002, was performed. Patients were classified as obese (BMI of greater than or equal to30 kg/m(2)), overweight (BMI of 25.0 to 29.9 kg/m(2)), normal weight (BMI of 20 to 24.9 kg/m(2)), or underweight (BMI of <20 kg/m(2)). In multivariate analyses, obesity was independently associated with death during PD treatment (hazard ratio, 1.36; 95% confidence interval, 1.14 to 1.54; P < 0.05) and technique failure (hazard ratio, 1.17; 95% confidence interval, 1.07 to 1.26; P < 0.01), except among patients of New Zealand Maori/Pacific Islander origin, for whom there was no significant relationship between BMI and death during PD treatment. A supplementary fractional polynomial analysis modeled BMI as a continuous predictor and indicated a J-shaped relationship between BMI and patient mortality rates and a steady increase in death-censored technique failure rates up to a BMI of 40 kg/m(2); the mortality risk was lowest for BMI values of approximately 20 kg/m(2). In conclusion, obesity at the commencement of renal replacement therapy is a significant risk factor for death and technique failure. Such patients should be closely monitored during PD and should be considered for early transfer to an alternative renal replacement therapy if difficulties are experienced.

Initial sequencing and analysis of the human genome.

Abstract: The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

The social identity theory of intergroup behavior

Abstract: This chapter presents an outline of a theory of intergroup conflict and some preliminary data relating to the theory. Much of the work on the social psychology of intergroup relations has focused on patterns of individual prejudices and discrimination and on the motivational sequences of interpersonal interaction. The intensity of explicit intergroup conflicts of interests is closely related in human cultures to the degree of opprobrium attached to the notion of "renegade" or "traitor." The basic and highly reliable finding is that the trivial, ad hoc intergroup categorization leads to in-group favoritism and discrimination against the out-group. Many orthodox definitions of "social groups" are unduly restrictive when applied to the context of intergroup relations. The equation of social competition and intergroup conflict rests on the assumptions concerning an "ideal type" of social stratification in which the salient dimensions of intergroup differentiation are those involving scarce resources.