987 resultados para cdte(100)
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New high-precision U/Pb geochronology from volcanic ashes shows that the Triassic-Jurassic boundary and end-Triassic biological crisis from two independent marine stratigraphic sections correlate with the onset of terrestrial flood volcanism in the Central Atlantic Magmatic Province to <150 ka. This narrows the correlation between volcanism and mass extinction by an order of magnitude for any such catastrophe in Earth history. We also show that a concomitant drop and rise in sea level and negative delta C-13 spike in the very latest Triassic occurred locally in <290 ka. Such rapid sea-level fluctuations on a global scale require that global cooling and glaciation were closely associated with the end-Triassic extinction and potentially driven by Central Atlantic Magmatic Province volcanism.
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An information briefing produced by the Department of Health - South East, based at the Government Office for the South East. The briefing acts as a signpost to public health and social care resources, evidence, policy, news and events.
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OBJECTIVE: Assess the performance of self-expanding venous cannulas for routine use in open-heart surgery. METHODS: Prospective study in 100 unselected consecutive patients undergoing open-heart surgery with either remote or central smart venous cannulation. RESULTS: The study focuses on the 76 consecutive adult patients (mean age 59.2+/-17.3 years; 60 males, 16 females) undergoing surgical procedures with total cardiopulmonary bypass for either valve procedures (42/76 patients=55.3%), ascending aorta and arch repair (20/76 patients=26.3%), coronary artery revascularization (13/76 patients=17.1%) or other procedures (11/76 patients=14.5%) with 14/76 patients (18.4%) undergoing redo surgery and 6/76 patients (7.9%) undergoing small access surgery. The mean pump flow achieved by gravity drainage alone accounted for 5.0+/-0.6l/min (=114% of target) in the entire study population (n=76) as compared to the calculated, theoretical pump flow of 4.4+/-0.5l/min (p<0.0001). For the femoral cannulation sub-group (n=35) pump flow achieved by gravity drainage alone accounted for 4.9+/-0.6l/min (=114% of target) as compared to the calculated theoretical pump flow of 4.3+/-0.4l/min (p<0.0001). The corresponding numbers for trans-subclavian cannulation (n=7) are 5.2+/-0.5l/min (111%) for the pump flow achieved by gravity drainage as compared to the theoretical target flow of 4.7+/-0.4l/min. For the central cannulation sub-group (n=34) mean flow achieved by gravity drainage with a self-expanding venous cannula accounted for 5.1+/-0.7l/min (=116% of target) as compared to the calculated theoretical flow of 4.4+/-0.6l/min (p<0.0001). CONCLUSION: Full or more than target flow was achieved in 97% of the patients studied undergoing CPB with self-expanding venous cannulas and gravity drainage. Remote venous cannulation with self-expanding cannulas provides similar flows as central cannulation. Augmentation of venous return is no longer necessary.
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Chagas disease originated millions of years ago as an enzootic infection of wild animals and began to be transmitted to humans as an anthropozoonosis when man invaded wild ecotopes. While evidence of human infection has been found in mummies up to 9,000 years old, endemic Chagas disease became established as a zoonosis only in the last 200-300 years, as triatomines adapted to domestic environments. It is estimated that 15-16 million people are infected with Trypanosoma cruzi in Latin America, and 75-90 million are exposed to infection. Control of Chagas disease must be undertaken by interrupting its transmission by vectors and blood transfusions, improving housing and areas surrounding dwellings, providing sanitation education for exposed populations and treating acute and recently infected chronic cases. These measures should be complemented by surveillance and primary, secondary and tertiary care.
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Semiconductor nanoparticles, such as quantum dots (QDs), were used to carry out experiments in vivo and ex vivo with Trypanosoma cruzi. However, questions have been raised regarding the nanotoxicity of QDs in living cells, microorganisms, tissues and whole animals. The objective of this paper was to conduct a QD nanotoxicity study on living T. cruzi protozoa using analytical methods. This was accomplished using in vitro experiments to test the interference of the QDs on parasite development, morphology and viability. Our results show that after 72 h, a 200 μM cadmium telluride (CdTe) QD solution induced important morphological alterations in T. cruzi, such as DNA damage, plasma membrane blebbing and mitochondrial swelling. Flow cytometry assays showed no damage to the plasma membrane when incubated with 200 μM CdTe QDs for up to 72 h (propidium iodide cells), giving no evidence of classical necrosis. Parasites incubated with 2 μM CdTe QDs still proliferated after seven days. In summary, a low concentration of CdTe QDs (2 μM) is optimal for bioimaging, whereas a high concentration (200 μM CdTe) could be toxic to cells. Taken together, our data indicate that 2 μM QD can be used for the successful long-term study of the parasite-vector interaction in real time.
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BACKGROUND. Ritonavir-boosted saquinavir (SQVr) is nowadays regarded as an alternative antiretroviral drug probably due to several drawbacks, such as its high pill burden, twice daily dosing and the requirement of 200 mg ritonavir when given at the current standard 1000/100 mg bid dosing. Several once-daily SQVr dosing schemes have been studied with the 200 mg SQV old formulations, trying to overcome some of these disadvantages. SQV 500 mg strength tablets became available at the end of 2005, thus facilitating a once-daily regimen with fewer pills, although there is very limited experience with this formulation yet. METHODS. Prospective, multicentre study in which efficacy, safety and pharmacokinetics of a regimen of once-daily SQVr 1500/100 mg plus 2 NRTIs were evaluated under routine clinical care conditions in either antiretroviral-naïve patients or in those with no previous history of antiretroviral treatments and/or genotypic resistance tests suggesting SQV resistance. Plasma SQV trough levels were measured by HPLV-UV. RESULTS. Five hundred and fourteen caucasian patients were included (47.2% coinfected with hepatitis C and/or B virus; 7.8% with cirrhosis). Efficacy at 52 weeks (plasma RNA-HIV <50 copies/ml) was 67.7% (CI95: 63.6 - 71.7%) by intention-to-treat, and 92.2% (CI95: 89.8 - 94.6%) by on-treatment analysis. The reasons for failure were: dropout or loss to follow-up (18.4%), virological failure (7.8%), adverse events (3.1%), and other reasons (4.6%). The high rate of dropout may be explained by an enrollment and follow-up under routine clinical care condition, and a population with a significant number of drug users. The median SQV Cmin (n = 49) was 295 ng/ml (range, 53-2172). The only variable associated with virological failure in the multivariate analysis was adherence (OR: 3.36; CI95, 1.51-7.46, p = 0.003). CONCLUSIONS. Our results suggests that SQVr (1500/100 mg) once-daily plus 2 NRTIs is an effective regimen, without severe clinical adverse events or hepatotoxicity, scarce lipid changes, and no interactions with methadone. All these factors and its once-daily administration suggest this regimen as an appropriate option in patients with no SQV resistance-associated mutations.
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MDL 100,240, a dual inhibitor of angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP), was administered intravenously to two panels of four healthy males in a four-period, dose-increasing (0, 1.56, 6.25, and 25 mg, and 0, 3.13, 12.5, and 50 mg, respectively) double-blind, placebo-controlled study. Plasma ACE activity and blood-pressure response to exogenous angiotensin I and angiotensin II i.v. challenges and safety and tolerance were assessed over a 24-h period. MDL 100,240 induced a rapid, dose-related, and sustained inhibition of ACE (>70% over 24 h at doses > or =12.5 mg). The time integral of ACE inhibition was related to the dose but with near-maximal values already attained at doses > or =12.5 mg. Systolic and diastolic blood-pressure responses to exogenous angiotensin I challenges were inhibited in a dose-dependent fashion, whereas the effects of angiotensin II remained unaffected. Mean supine blood pressure decreased transiently (3 h) at doses > or =3.125 mg and < or =24 h with the 25- and 50-mg doses, but not significantly. MDL 100,240 was well tolerated. In healthy subjects, MDL 100,240 exerts a dose-dependent and long-lasting ACE-blocking activity, also expressed by the inhibition of the pressor responses to exogenous angiotensin I challenges. The baroreceptor reflex, assessed by the response to exogenous angiotensin II challenge, remains unaltered.
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Little information is available as to whether doses of iodide similar to those recommended in clinical practice for the prevention of iodine deficiency in pregnant women affect thyroid function. The aim of the present study was to analyse whether doses of iodide can affect thyroid function in adults, and evaluate its effect on plasma markers of oxidative stress, inflammation and acute-phase proteins. A total of thirty healthy volunteers (ten men and twenty women) with normal thyroid function were randomly assigned to three groups (n 10). Each group received a daily dose of 100, 200 or 300 μg of iodide in the form of KI for 6 months. Free tetraiodothyronine (FT4) levels at day 60 of the study were higher in the groups treated with 200 and 300 μg (P = 0·01), and correlated with the increase in urinary iodine (r 0·50, P = 0·007). This correlation lost its significance after adjustment for the baseline FT4. The baseline urinary iodine and FT4 correlated positively with the baseline glutathione peroxidase. On day 60, urinary iodine correlated with C-reactive protein (r 0·461, P = 0·018), and free triiodothyronine correlated with IL-6 (r - 0·429, P = 0·025). On day 60, the changes produced in urinary iodine correlated significantly with the changes produced in α1-antitrypsin (r 0·475, P = 0·014) and ceruloplasmin (r 0·599, P = 0·001). The changes in thyroid-stimulating hormone correlated significantly with the changes in α1-antitrypsin (r - 0·521, P = 0·005) and ceruloplasmin (r - 0·459, P = 0·016). In conclusion, the administration of an iodide supplement between 100 and 300 μg/d did not modify thyroid function in a population with adequate iodine intake. The results also showed a slight anti-inflammatory and antioxidative action of iodide.
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Boletín semanal para profesionales sanitarios de la Secretaría General de Salud Pública y Participación Social de la Consejería de Salud
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Référence bibliographique : Rol, 55187
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Référence bibliographique : Rol, 55062
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Référence bibliographique : Rol, 54192
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Référence bibliographique : Rol, 55052