A previous limited study demonstrated that Mycobacterium tuberculosis isolates with a mutation at amino-acid position 315 of katG (Delta315) exhibited high-level resistance to isoniazid and were more frequently resistant to streptomycin. In the present study, isoniazid-resistant M. tuberculosis isolates from 8,332 patients in The Netherlands (1993-2002) were screened for the Delta315 mutation. Isoniazid resistance was found in 592 (7%) isolates, of which 323 (55%) carried Delta315. IS6110 restriction fragment length polymorphism analysis showed that Delta315 isolates occurred in clusters, suggesting recent transmission, at the same frequency as isoniazid-susceptible isolates. In contrast, other isoniazid-resistant isolates clustered significantly less frequently. Delta315 isolates were high-level isoniazid-resistant, streptomycin-resistant and multidrug-resistant significantly more often, and may have a greater impact on public health, than other isoniazid-resistant isolates. 相似文献
AIM: Cardiac infarction is one of the main causes of death in both developing and developed countries over past decades. Currently available approaches for treating patients with this disease are not satisfactory. Traditional Chinese medicines have been increasingly paid attention to. The aim of this study was to characterize the dynamic protective effects of Guanxin No. 2 decoction (GX II) on cardiac dysfunction combined with the blood viscosity and myocardial hypertrophy parameters in myocardial infarction (MI) rats. METHODS: Male Sprague-Dawley rats (180-200 g) were randomly divided into three groups: sham-operated, coronary artery ligation (CAL), and CAL plus GX II (GX II, 10.0 g raw materials/kg/d, bid, p.o.). The experiment was carried out at 4 time points as the 3rd, 7th, 14th, and 28th day after ligation. RESULT: It was found that on the one hand, GX II could significantly improve the heart function, and remarkably decrease infarct size and inhibit ventricular remodeling. On the other hand, GX II showed some unique effects such as angiogenesis which was induced in the left ventricular tissue. This result was consistent with the finding of an augmented vascular endothelial growth factor (VEGF) expression in this area. CONCLUSIONS: The studies demonstrated that GX II exerted extensively beneficial cardioprotective effect on CAL rats, it might stimulate angiogenesis of ischemic region to compensate blood supply to the heart via upregulated VEGF expression. 相似文献
ObjectivesThe purpose of this study was to educate on the moderating effects of demographic (i.e., educational level and age) and individual characteristics (i.e., years of nursing experience and computer knowledge) on nurses’ acceptance of information systems (IS). The technology acceptance model (TAM) with its constituent variables such as perceived usefulness (PUSS) and perceived ease of use (PEOU) was the theoretical framework used for this study.MethodsA cross-sectional study was conducted in Nova Scotia, Canada. Usable data was collected from 197 registered nurses (RNs). Relevant hypotheses were formulated and the partial least squares (PLS) technique was used for data analysis.ResultsThe results of the hypothesized relationships showed that education and computer knowledge have positive moderating effects on the influences of PEOU and PUSS on nurses’ attitudes toward IS (ATTI). The factors of nurses’ years of nursing experience and age did not yield meaningful results. ATTI impacted behavioral intentions to use IS, which positively impacted nurses’ use of IS. The nurses sampled in the study have positive IS use behaviors.ConclusionsThis study demonstrates that relevant demographic factors and individual characteristics, if incorporated into frameworks used for investigating nurses’ acceptance of IS, could permit the emergence of useful insights for practitioners and researchers. Specifically, this study showed that nurses with higher educational attainments and more basic computer knowledge readily accept implemented IS at work. Hospital administrators benefit from insights such as the one presented in this study. 相似文献
For almost a century, the scientific community is aware of the J-shaped curve between alcohol consumption and all-cause mortality. Moderate drinkers seem to live longer than both abstainers and heavy drinkers. These epidemiological observations regarding moderate alcohol consumption and beneficial health effects have been incessantly scrutinised for confounding and bias. This viewpoint discusses previous and recent criticisms regarding the J-shaped curve between alcohol consumption and total mortality risk. The controversies regarding the J-shaped curve between alcohol consumption and mortality are ongoing, as well as the debate among scientists in this area of research, resulting in conflicting messages in media and in different alcohol guidelines. Although it appears quite difficult to come up with a position statement only based on the currently available scientific data, it is imperative to fairly inform the public, without creating confusion and, worst case, disbelief in science. 相似文献
We tested to find out whether pravastatin restores the infarct size (IS)-limiting effect of ischemic preconditioning (IP) and if it has any effect on the IP-induced activation of adenosine producing enzyme ecto-5′-nucleotidase which plays a key role in the IP-induced cardioprotection.
BACKGROUND
The IS-limiting effect of IP is blunted by hypercholesterolemia. Recently, HMG-CoA reductase inhibitors are shown to have direct cytoprotective effects.
METHODS
Rabbits were fed with a normal or cholesterol (1%) added diet with or without pravastatin (5 mg/kg/day) treatment. Infarct size was measured after 30 min occlusion and 3 h reperfusion of circumflex coronary artery with or without the IP procedure (5 min occlusion and 10 min reperfusion). Additionally, ecto-5′-nucleotidase activities of ischemic and nonischemic myocardium were measured immediately after IP procedure.
RESULTS
This dose of pravastatin did not normalize the increased level of serum cholesterol. The IS-limiting effect of preceding IP (IS reduced from 36.7% to 9.6%, p < 0.001) was abolished by hypercholesterolemia (from 46.1% to 31.3%, p = NS) and restored by pravastatin treatment (from 35.2% to 9.4%, p < 0.001). Pravastatin treatment did not affect IS or the effect of IP under normocholesterolemia. The activation of ecto-5′-nucleotidase presented as the activity ratio of ischemic to nonischemic myocardium (3.1-fold in normocholesterolemia) was blunted by hypercholesterolemia (1.8-fold, p < 0.05) and restored by pravastatin treatment (2.9-fold).
CONCLUSIONS
Pravastatin, at the dose serum cholesterol was not normalized, restored the IS-limiting effect of IP and IP-induced ecto-5′-nucleotidase activation, which were both blunted by hypercholesterolemia. The activation of ecto-5′-nucleotidase may be worth further investigation as a possible mechanism for the hypercholesterolemia-induced retardation and pravastatin-mediated restoration of the cardioprotective effect of IP. 相似文献