PM10 metal distribution in an industrialized city.
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Biomedical subjects
Publications and source records attributed to Y-F Chang.
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Experimental borrelia infection was induced in 62 specific--pathogen-free beagle dogs by exposure to Ixodes scapularis ticks harbouring the spirochaete Borrelia burgdorferi. Clinical signs of Lyme disease occurred in 39/62 dogs, the remaining 23 being subclinically infected. Clinical signs consisted of one to six episodes of transitory lameness with joint swelling and pain, most commonly affecting the elbow or shoulder joints. The polymerase chain reaction and culture demonstrated that the dogs remained infected for up to 581 days. At necropsy, gross findings consisted of lymphadenopathy in the area of tick attachment. Microscopical changes consisted of effusive fibrinosuppurative inflammation or nonsuppurative inflammation, or both, affecting synovial membranes, joint capsules and associated tendon sheaths. Plasma cells dominated areas of chronic inflammation, with CD3(+) T cells being present in lesser numbers. Microscopical signs of arthritis were polyarticular and more widespread than indicated by clinical signs, and most of the subclinically affected animals also had synovitis. In areas of tick attachment to the skin, hyperkeratosis and a mixture of suppurative and nonsuppurative dermatitis were encountered. Lymphadenopathy in superficial lymph nodes resulted from follicular and parafollicular hyperplasia. In 14/62 dogs, lymphoplasmacytic periarteritis and perineuritis were noted, resembling lesions found in human Lyme disease and syphilis, in which an underlying microangiopathy has been proposed.
Expression of CD44s (standard form) in malignant lymphoma is a poor indicator of survival. To investigate whether activation of CD44s can protect from cell death, this study compared the extent of apoptosis induced by chemotherapeutic agents and ionizing radiation (IR) on T-lymphoma cell lines in the presence or absence of adherent hyaluronan and monoclonal antibodies (MoAbs). Growth in the presence of adherent ligands enhanced apoptosis induced by dexamethasone (Dex), but protected cells from epirubicin-induced apoptosis. In IR-induced apoptosis, mouse lymphoma cells had resistance against apoptosis when treated with hyaluronan (HA), although acute cell death reached the same plateau regardless of treatment with adherent MoAbs in human lymphoma cell line. However, the post-irradiated repopulation of lymphoma cells was strikingly accelerated in those treated with CD44 adherent ligands. This repopulation process correlated with the remarkable upregulation of proliferating cell nuclear antigen (PCNA), which is a protein involved in DNA repair. Unscheduled DNA synthesis (UDS), a measure of DNA repair, was consistently enhanced in CD44s-stimulated cells after exposure to radiation. The results suggest that the poor prognostic indication of CD44 expression is more a consequence of enhanced DNA repair following genotoxic damage than of direct resistance to apoptosis.
OBJECTIVE: To report our experience with repeat microvascular decompression (MVD) for hemifacial spasm (HFS) in patients who have failed their first operation. METHODS: The authors describe 41 redo MVDs for HFS in 36 patients performed over a 3 year period. Seven patients underwent early re-operation after an aborted seventh nerve decompression. Eight patients underwent early re-operation for clinical failure. Eighteen patients underwent late re-operation for spasm recurrence long after their original MVD. Eight MVDs were performed on patients who had already undergone at least two prior operations. RESULTS: Twenty four patients experienced complete spasm resolution (70.6%), eight patients had near total resolution (23.5%), and two patients failed re-operation (5.9%). Two patients were lost to follow up (5.6%). A favourable outcome was reported by 82.4% of patients at a mean follow up interval of 18 months. A total of 91.7% of patients 50 years of age or younger were cured at follow up versus 59.1% of patients older than 50 (p = 0.04). Patients undergoing early re-operation were significantly more likely to be cured or improved than patients undergoing late re-operation (p = 0.03). CONCLUSIONS: Repeat MVD for HFS is effective in experienced hands. Younger patients respond better to repeat MVD. Late repeat MVD for HFS is a reasonable treatment option, although results are less favourable than for early re-operation.
Recently, five novel fluorescent proteins have been isolated from non-bioluminescent species of reef-coral organisms and have been made available through ClonTech. They are AmCyan, AsRed, DsRed, ZsGreen and ZsYellow. These proteins are valuable as reporters for transformation because they do not require a substrate or external co-factor to emit fluorescence and can be tested in vivo without destruction of the tissue under study. We have evaluated them in a large range of plants, both monocots and dicots, and our results indicate that they are valuable reporting tools for transformation in a wide variety of crops. We report here their successful expression in wheat, maize, barley, rice, banana, onion, soybean, cotton, tobacco, potato and tomato. Transient expression could be observed as early as 24 h after DNA delivery in some cases, allowing for very clear visualization of individually transformed cells. Stable transgenic events were generated, using mannose, kanamycin or hygromycin selection. Transgenic plants were phenotypically normal, showing a wide range of fluorescence levels, and were fertile. Expression of AmCyan, ZsGreen and AsRed was visible in maize T1 seeds, allowing visual segregation to more than 99% accuracy. The excitation and emission wavelengths of some of these proteins are significantly different; the difference is enough for the simultaneous visualization of cells transformed with more than one of the fluorescent proteins. These proteins will become useful tools for transformation optimization and other studies. The wide variety of plants successfully tested demonstrates that these proteins will potentially find broad use in plant biology.
AIM/HYPOTHESIS: To examine whether nuclear magnetic resonance lipoprotein spectroscopy improves the prediction of coronary artery disease in patients with Type 1 diabetes, independently of conventional lipid and other risk factors. METHODS: A prospective nested case-control design of subjects with childhood onset Type 1 diabetes from the Pittsburgh Epidemiology of Diabetes Complications Study was used. 59 controls were age-, sex- and duration-matched to 59 incident cases of coronary artery disease (fatal or non-fatal myocardial infarction, angina, coronary stenosis >50%) occurring during 10 years of follow-up. Lipid mass and particle concentrations of VLDL, LDL, and HDL subclasses, grouped into three size categories (large, medium, and small), were assessed prior to event with nuclear magnetic resonance spectroscopy. RESULTS: Univariate analyses showed that both lipid mass and particle concentrations of all three VLDL subclasses, small LDL, medium LDL, and medium HDL were increased in CAD cases compared to controls, while large HDL was decreased. Mean LDL and HDL particle sizes were lower in cases. In multivariate models using conventional lipid and non-lipid risk factors, triglycerides and overt nephropathy were the strongest predictors of CAD. Nuclear magnetic resonance measures further improved the prediction, i.e. large HDL particle concentration (OR=0.43, p=0.030), medium HDL mass (OR=3.79, p=0.026) and total VLDL particle concentration (OR=2.33, p=0.033). CONCLUSION/INTERPRETATION: While these results underscore the importance of triglycerides and overt nephropathy in CAD risk in Type 1 diabetic patients, they also suggest that nuclear magnetic resonance lipoprotein spectroscopy could further refine its prediction and show novel findings concerning HDL subclasses.
STUDY OBJECTIVE: Little is known about the number of women who identify as lesbian. Estimates from the US range from 1% to nearly 10%. Accurate estimates are critical in order to meet lesbian's healthcare needs and to address health problems that may be more prevalent among them. This study used capture-recapture methods to estimate the lesbian population of Allegheny County, Pennsylvania. DESIGN: Mailing lists from four sources were used to identify lesbians. The capture-recapture method and log-linear modelling were used to estimate the number of lesbians in the defined geographical area, and the percentage of the female population they comprised there was determined through census data. SETTING: Allegheny County, Pennsylvania, USA. RESULTS: A total of 2185 unique names were identified. The capture-recapture method estimated that the total lesbian population of Allegheny County was 7031 (95% CI 5850 to 8576). Therefore, based on the 1990 census figures, the county's adult lesbian population was estimated to be 1.87% (95% CI 1.56% to 2.28%) of the adult female population. CONCLUSIONS: An estimate of the lesbian population is fundamental for addressing lesbian's health needs and for developing appropriate research programmes. Capture-recapture methods have the potential to provide accurate and reliable estimates of this population in any location.
This investigation used a two-source capture-recapture method (CRM) for determining ascertainment and undercounts of non-national priority listed hazardous waste sites in the states of Arizona, Maine and Pennsylvania. These findings suggest that ascertainment of hazardous waste sites vary greatly, with some more accurate (i.e., Maine) than others (i.e., Pennsylvania). These data suggest that nontraditional manufacturing states (e.g., Maine) have a higher ascertainment rate than traditional manufacturing states (e.g., Pennsylvania). These results indicate that resources for locating hazardous waste sites should be more heavily allotted to industrialized areas. We suggest that the CRM is a convenient, low cost and effective method for determining (1) the accuracy of previous estimates, and (2) the number of sites in a locale with 95% confidence intervals along with an estimate of the undercount. Findings suggest that estimates of hazardous waste sites should use the CRM to determine and improve accuracy.