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Biomedical subjects

K Wu

Publications and source records attributed to K Wu.

313 records · Page 18Linked to original sources
PubMedDate not supplied

Expression and function of CD43 and CDw60 on T cells from patients with atopic dermatitis.

Signalling via the CD43 and CDw60 epitopes has been reported as providing two novel pathways of T-lymphocyte activation. In Wiskott-Aldrich syndrome, which has atopic eczema-like skin symptoms, there is a defective expression of CD43, while CDw60 is strongly expressed on T cells from rheumatoid arthritis synovial fluid and from psoriatic skin lesions, and on blood mononuclear cells from patients with cutaneous T-cell lymphoma. We therefore studied the expression and function of these phenotypes on peripheral blood mononuclear cells and on CD4+ and CD8+ T-cell subsets from patients with atopic dermatitis. We observed a significant increase in the percentage of CD43+ cells among the blood mononuclear cells in patients with atopic dermatitis and an enhanced proliferation of CD4+ T cells following stimulation with anti-CD43 antibody. There were no changes in the CDw60 expression or function after stimulation with anti-CDw60 antibody. Thus, CD43 expression was not decreased but rather increased in blood mononuclear cells from patients with atopic dermatitis, whereas CDw60 expression did not differ from healthy controls.

Adult↗
PubMedDate not supplied

Human nails as a biomarker of arsenic exposure from well water in Inner Mongolia: comparing atomic fluorescence spectrometry and neutron activation analysis.

Arsenic (As) is found naturally in the geological strata within the Ba Men Region of Inner Mongolia, China. A study was conducted to compare the total As measurements from two analytical techniques: instrumental neutron activation analysis (INAA) and atomic fluorescence spectrometry (AFS), and to verify nails as an exposure biomarker in this population. In 1999, nail and water samples were collected in a pilot study. Fingernails and toenails were pooled from 32 participants and analysed for total As by both INAA and AFS. Mean nail As values were 14.8+/-2.4 and 19.4+/-2.8 microg g-1 (+/-SEM) for INAA and AFS, respectively. Results from these two methods were significantly correlated (r=0.93, p<0.0001). In 2000, a second study was conducted and INAA was used to measure total As in toenails from 314 Ba Men residents. Well water samples were collected from 121 households and analysed by AFS. A significant correlation was observed between toenail and well water As (r=0.84, p<0.0001). Based on the results, INAA was significantly correlated with AFS and proved to be a reliable measure of nail As levels. In this population, toenail samples are a useful internal As exposure biomarker from drinking water sources.

Adult↗
PubMedDate not supplied

Distribution, severity and risk factors for aortic atherosclerosis in cerebral ischemia.

Significant thoracic aortic plaques (>4 mm) are an independent risk factor for ischemic stroke. Within 1 week of stroke/transient ischemic attack (TIA) onset, 105 consecutive patients underwent transesophageal echocardiography assessment of aortic plaque thickness using the criteria of Amarenco et al. (N Engl J Med 1994;331:1474-1479). A proximo-distal gradient was found in the distribution of aortic atheroma >4 mm (p = 0.04). Symptomatic coronary artery disease was associated with plaque in the proximal aorta (p = 0.03); extracranial carotid stenosis >70% was associated with plaque in the arch and descending aorta (p < 0.01). The severity of aortic plaque was associated with age on multivariable analysis (p = 0.0003 to p < 0.01). Only smoking showed predictive regional specificity (p = 0.03);no other risk factors were associated with aortic atheroma in any segment. In stroke/TIA patients, carotid stenosis >70% predicts aortic arch atheroma plaques >4 mm which may predispose to reinfarction after endarterectomy. Atheroma of the ascending aorta is associated with ischemic heart disease, and cardiac screening should be considered in asymptomatic patients.

Adult↗
PubMedDate not supplied

DNA damage in buccal epithelial cells from individuals chronically exposed to arsenic via drinking water in Inner Mongolia, China.

The purpose of this pilot study was to assess DNA damage in buccal cells from individuals chronically exposed to arsenic via drinking water in Ba Men, Inner Mongolia. Buccal cells were collected from 19 Ba Men residents exposed to arsenic at 527.5 +/- 23.7 micrograms/L (mean +/- SEM) and 13 controls exposed to arsenic at 4.4 +/- 1.0 micrograms/L. DNA fragmentation by the DNA ladder and TUNEL assay were used to detect DNA damage in buccal cells. In the DNA ladder assay, 89% (17/19) of the arsenic-exposed group showed < 100 bp DNA fragments, in contrast to 15% (2/13) of the controls (p < 0.0001). For the TUNEL assay, the mean frequencies of positive cells were higher in the exposed group (15.1%) than in the controls (2.0%) (p < 0.0001). This study showed that high arsenic exposure via drinking water resulted in DNA damage and DNA fragmentation in buccal cells thus may be an appropriate biomarker for assessing chronic effects of arsenic in humans. A study investigating DNA fragmentation from the individuals with low levels of arsenic exposure in this population is in progress.

Adolescent↗
PubMedDate not supplied

Health care utilization and disability of migraine: the Ontario Health Survey.

OBJECTIVE: To measure the prevalence of migraine, associated functional disabilities, use of medications and visits to physicians. DESIGN: 135,062 migraineurs in Ontario were estimated from the Ontario Health Survey (OHS). The population demographics, use of medications and visits to physicians were compared with these measures in individuals without migraine. RESULTS: The prevalence of migraine was estimated at 1.4% in Ontario. The migraineurs were heavy users of both prescription and non prescription drugs (98.0%). They were heavier users of pain relievers than the comparison group (91.2% versus 58.2%, p < 0.0000). According to the two-week disability reports, 11% of them were bedridden for an average of 1.6 days and 9.3% were restricted from normal activities for an average of 2.4 days because of migraine. CONCLUSIONS: Severe migraine headaches may result in a $31 million loss in productivity and $2 million in hospitalization costs. The findings of this study highlight both the medical and financial impact of migraine on the individual and the health care systems.

Absenteeism↗
PubMedDate not supplied

Novel mechanism to enhance tPA-induced fibrinolysis: effect of limited proteolysis of PAI-1 by neutrophil elastase.

The effect of the proteolytic cleavage of plasminogen activator inhibitor type 1 (PAI-1) by human neutrophil elastase (HNE) on fibrinolysis was investigated. HNE cleaved active recombinant prokaryotic PAI-1 (rpPAI-1) resulting in the formation of low molecular weight forms of rpPAI-1 as previously reported. The latent form of rpPAI-1 was resistant to HNE. NH2-terminal sequence analysis indicated that the cleavage site was Val355-Ser356 (P4-P3). The fact that the strained loop of the latent form of PAI-1 is buried inside the molecule most likely accounts for its resistance to HNE. After the cleavage by HNE, active rpPAI-1 lost its specific activity toward plasminogen activators. The cleavage was both enzyme concentration and time dependent, and the almost complete inactivation of rpPAI-1 (2.9 microM) activity was obtained by a HNE (83 nM) treatment for 30 min at 37 degrees C. Vitroectin partially protected active rpPAI-1 from the HNE digestion. The effect of PAI-1 cleavage by HNE on tissue type PA (tPA) induced clot lysis was studied in a purified system. Clot lysis time without rpPAI-1 was 20.0 +/- 5.0 min, and was prolonged to 86.7 +/- 2.9 min by 68 nM of rpPAI-1. It was shortened when HNE (from 0.6 nM to 80 nM) was added and returned to the value obtained without rpPAI-1 when 80 nM of HNE was present (20.0 +/- 5.8 min). In the absence of PAI-1, however, HNE did not enhance clot lysis at all. The cleavage and inactivation of PAI-1 by HNE was shown to be a novel pathway to enhance fibrinolysis.

Amino Acid Sequence↗