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.

SYNbiotics Easing Renal failure by improving Gut microbiologY (SYNERGY): a protocol of placebo-controlled randomised cross-over trial

Abstract: Emerging evidence suggests modulating the microbiota in the large bowel of patients with chronic kidney disease (CKD) through pre- and/probiotic supplementation may inhibit the development of key nephrovascular toxins. To date, quality intervention trials investigating this novel treatment in CKD are lacking. The aim of SYNERGY is to assess the effectiveness of synbiotics (co-administration of pre- and probiotics) as a potential treatment targeting the synthesis of uremic toxins, specifically, indoxyl sulphate (IS) and p-cresyl sulphate (PCS). Thirty-seven patients with moderate to severe CKD (Stage IV and V, pre-dialysis) will be recruited to a double-blind, placebo-controlled, randomised cross-over trial. Patients will be provided with synbiotic therapy or placebo for 6 weeks, with a 4 week washout before cross-over. The primary outcome is serum IS, total and free (unbound) concentrations, measured using ultra-performance liquid chromatography. Secondary outcomes include serum PCS, total and free (unbound) concentrations; cardiovascular risk, measured by serum lipopolysaccharides, serum trimethylamine-N-oxide (TMAO) and inflammation and oxidative stress markers; kidney damage, measured by 24 hour proteinuria and albuminuria, estimated glomerular filtration rate and renal tubule damage (urinary kidney injury molecule-1); patients’ self assessed quality of life; and gastrointestinal symptoms. In addition, the effects on the community structure of the stool microbiota will be explored in a subset of patients to validate the mechanistic rationale underpinning the synbiotic therapy. IS and PCS are two novel uremic toxins implicated in both cardiovascular disease (CVD) and progression of CKD. Preliminary studies indicate that synbiotic therapy maybe a promising strategy when considering a targeted, tolerable and cost-efficient therapy for lowering serum IS and PCS concentrations. This trial will provide high quality ‘proof-of-concept’ data to elucidate both the efficacy of synbiotic therapy for lowering the toxins and whether reductions in serum IS and PCS translate into clinical benefits. Considering the potential of pre- and probiotics to not only shift toxin levels, but to also impede CVD and CKD progression, SYNERGY will provide vital insight into the effectiveness of this innocuous nutritional therapy. Universal Trial Number: U1111-1142-4363. Australian New Zealand Clinical Trials Registry Number: ACTRN12613000493741 , date registered: 2nd May 2013.

Confined alpha distribution measurements in a deuterium-tritium tokamak plasma.

Abstract: Fusion-produced alpha particles with energy {le}0.7 MeV have been spectroscopically observed in the core of a deuterium-tritium plasma in the TFTR tokamak at alpha densities of 3{times}10{sup 16}m{sup {minus}3}. During a sawtooth-free discharge, the measured energy spectra at {ital r}/{ital a}=0.3 are in good agreement with those predicted on the basis of collisional transport. Time-resolved measurements during the alpha thermalization after alpha source turn-off show decay of the distribution function to lower energies consistent with the classical slowing-down time of 0.5 s.

Caller satisfaction with after-hours telephone advice: nurse advice service versus on-call pediatricians.

Abstract: To the Editor .— In their recent article, Lee et al1 report that callers seeking after-hours triage and advice were less satisfied with medical advice provided by a nurse service compared with an on-call pediatrician. In this study, a large national for-profit service bureau that offers many different types of telephone services, including information, referral management, and hospital marketing calls, provided the triage services. The authors devote considerable time in the article addressing the study’s limitations, including the question of whether the study findings can be generalized to other practice settings. They speculate that satisfaction may have been greater if a children’s hospital call center had been utilized. The results reported by Lee et al (55% satisfaction rate with nurse triage) stand in contrast to other studies that have reported patient satisfaction rates of 94% to 98%2–4 for hospital-based pediatric nurse triage services. Two factors might account for differences in satisfaction between parents using children’s hospital programs and a national service bureau—the level of pediatric nursing expertise and the protocols used. In many offices and hospital call centers, managers place a premium on a high level of pediatric expertise in recruiting telephone nurses, and train …

Focus on peritoneal dialysis training: working to decrease peritonitis rates

Abstract: Patient training has widely been considered to be one of the most critical factors for achieving optimal peritoneal dialysis clinical outcomes, including avoidance of peritonitis. However, research in this important area has been remarkably scant to date. This article will critically review the clinical evidence underpinning PD patient training and will specifically focus on four key areas: who should provide training and how, when and where should it be performed to obtain the best results. Evidence gaps and future research directions will also be discussed.

Effectiveness of Conflict Managers in an Inner-City Elementary School.

Abstract: The effectiveness of an inner-city peer mediation program was examined. Forty-seven 3rd- and 4th-grade students in a prekindergarten to 4th-grade elementary school were trained as conflict managers to mediate schoolmates' conflicts. The training consisted of 1 1/2 days of training in communication, assertiveness, and mediation skills. The students mediated 323 conflicts during the academic year. Eighty-seven percent of the conflicts brought to mediation concerned relationship problems involving physical attacks (43%) and verbal attacks (42%). The strategies students most commonly used were physical force (40%) and verbal force (51%). Mediation most commonly resulted in an agreement to avoid each other in the future (84%). There were no significant differences among male-male, female-female, and male-female conflicts, although male-female conflicts were relatively nonexistent in these young children.

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.