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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.


Papers
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Journal ArticleDOI
TL;DR: This work investigated 47 herbs for their in vitro toxic or antioxidant effects on normal renal mammalian fibroblasts and tubular epithelial cells to determine their potential value as therapeutic agents in renal fibrosis involving oxidative stress.
Abstract: SUMMARY: Aim: Renal fibrosis is central to progression of most chronic renal pathologies. Antioxidants that protect the tubular epithelium and anti-fibrotics that induce apoptosis of pro-fibrotic myofibroblasts without adversely affecting tubular epithelium may slow progression of renal fibrosis, while toxic substances may exacerbate renal scarring. We investigated 47 herbs for their in vitro toxic or antioxidant effects on normal renal mammalian fibroblasts (NRK49F) and tubular epithelial cells (NRK52E) to determine their potential value as therapeutic agents in renal fibrosis involving oxidative stress. Methods: Herbs were chosen because of their traditional use in kidney or urinary system disorders, or because of recent published interest in their therapeutic or toxic potential in kidney disease. Extracts of herbs were made using a sequential multi-solvent extraction process. Each extract was analysed separately. Extraction solvents were ethyl acetate, methanol and 50% aqueous methanol. Cells were treated with extracts with/without oxidative stress (1.0 mM hydrogen peroxide). Cellular changes (apoptosis, necrosis, mitosis, transdifferentiation) were identified and quantified using defined criteria. Results: All extracts of Dioscorea villosa showed significant toxicity to both cell lines. At low concentrations (5‐50 mg/mL) they induced epithelial to mesenchymal transdifferentiation, as demonstrated by increased immunohistochemistry staining for a-smooth muscle actin and transforming growth factor-b1 in treated versus control cells. Angelica sinensis, Centella asiatica, Glycyrrhiza glabra, Scutellaria lateriflora, and Olea europaea demonstrated strong antioxidant effects in epithelial cells and/or apoptotic effects on fibroblasts. Conclusion: This investigation has revealed renotoxicity of D. villosa and anti-fibrotic, oxidant potential of several herbal extracts, all of which require further study.

47 citations

Journal ArticleDOI
TL;DR: A special focus should be placed on examining clinically translatable strategies that might encourage improvements to the microbiome, thereby potentially reducing the risk of the development of chronic kidney disease.
Abstract: It is well-established that uremic toxins are positively correlated with the risk of developing chronic kidney disease and cardiovascular disease. In addition, emerging data suggest that gut bacteria exert an influence over both the production of uremic toxins and the development of chronic kidney disease. As such, modifying the gut microbiota may have the potential as a treatment for chronic kidney disease. This is supported by data that suggest that rescuing microbiota dysbiosis may: reduce uremic toxin production; prevent toxins and pathogens from crossing the intestinal barrier; and, reduce gastrointestinal tract transit time allowing nutrients to reach the microbiota in the distal portion of the gastrointestinal tract. Despite emerging literature, the gut-kidney axis has yet to be fully explored. A special focus should be placed on examining clinically translatable strategies that might encourage improvements to the microbiome, thereby potentially reducing the risk of the development of chronic kidney disease. This review aims to present an overview of literature linking changes to the gastrointestinal tract with microbiota dysbiosis and the development and progression of chronic kidney disease.

47 citations

Journal ArticleDOI
TL;DR: Patterns of individual differences were found which support the conclusion that individual differences in auditory performance are, in part, a function of patterns of independent abilities.
Abstract: Twenty-eight audiometrically normal adult listeners were given a variety of auditory tests, ranging from quiet and masked thresholds through the discrimination of simple and moderately complex temporal patterns. Test-retest reliability was good. Individual differences persisted on a variety of psychoacoustic tasks following a period of training using adaptive threshold-tracking methods, and with trial-by-trial feedback. Large individual differences in performance on temporal-sequence-discrimination tasks suggest that this form of temporal processing may be of clinical significance. In addition, high correlations were obtained within given classes of tests (as, between all tests of frequency discrimination) and between certain classes of tests (as, between tests of frequency discrimination and those of sequence discrimination). Patterns of individual differences were found which support the conclusion that individual differences in auditory performance are, in part, a function of patterns of independent abilities.

47 citations

Journal ArticleDOI
TL;DR: Significant areas of high consensus suggest "online behaviors" that physicians should never engage in, whereas moderate- and low-consensus areas provide useful contextual information about "gray areas."
Abstract: Despite recent guidelines promoting online professionalism, consequences for specific violations by physicians have not been explored In this article, the authors gauged consensus among state medical boards in the United States (response rate, 71%) about the likelihood of investigations for violations of online professionalism by using 10 hypothetical vignettes High consensus was defined as more than 75% of respondents indicating that investigation was "likely" or "very likely," moderate consensus as 50% to 75% indicating this, and low consensus as fewer than 50% indicating this Four online vignettes demonstrated high consensus: Citing misleading information about clinical outcomes (81%; 39/48), using patient images without consent (79%; 38/48), misrepresenting credentials (77%; 37/48), and inappropriately contacting patients (77%; 37/48) Three demonstrated moderate consensus for investigation: depicting alcohol intoxication (73%; 35/48), violating patient confidentiality (65%; 31/48), and using discriminatory speech (60%; 29/48) Three demonstrated low consensus: using derogatory speech toward patients (46%; 22/48), showing alcohol use without intoxication (40%; 19/48), and providing clinical narratives without violation of confidentiality (16%; 7/48) Areas of high consensus suggest "online behaviors" that physicians should never engage in, whereas moderate- and low-consensus areas provide useful contextual information about "gray areas" Increased awareness of these specific behaviors may reduce investigations and improve online professionalism for physicians

47 citations


Cited by
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Journal ArticleDOI
Eric S. Lander1, Lauren Linton1, Bruce W. Birren1, Chad Nusbaum1  +245 moreInstitutions (29)
15 Feb 2001-Nature
TL;DR: The results of an international collaboration to produce and make freely available a draft sequence of the human genome are reported and an initial analysis is presented, describing some of the insights that can be gleaned from the sequence.
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.

22,269 citations

28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组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�ly.
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。

18,940 citations

Book ChapterDOI
09 Jan 2004
TL;DR: A theory of intergroup conflict and some preliminary data relating to the theory is presented in this article. But the analysis is limited to the case where the salient dimensions of the intergroup differentiation are those involving scarce resources.
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.

14,812 citations

Journal ArticleDOI
TL;DR: In this paper, Imagined communities: Reflections on the origin and spread of nationalism are discussed. And the history of European ideas: Vol. 21, No. 5, pp. 721-722.

13,842 citations

Journal ArticleDOI
TL;DR: Reading a book as this basics of qualitative research grounded theory procedures and techniques and other references can enrich your life quality.

13,415 citations