990 resultados para Respiration rate


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Clinical and virologic manifestations of genital herpes simplex virus type 2 (HSV-2) infection vary widely. We examined frequencies of single-nucleotide polymorphisms (SNPs) in Toll-like receptors (TLRs) 2, 3, 4, and 9 in a prospective cohort of 128 HSV-2-infected persons whose viral shedding and lesion frequency was measured by daily sampling from genital secretions. Two TLR2 haplotypes (2 and 4) were associated with increased lesional (P=.008 and P=.03) and shedding (P=.02 and P=.001) rates. An SNP in haplotype 2 (-15607A/G) was also associated with shedding (P=.01) and lesional (P=.008) rates. Polymorphisms in TLR2 may be in part responsible for differences in the severity of HSV-2 infection.

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Background: Adverse drug reactions (ADRs) are a threat to patients' health and quality of life, and can generate significant expenses. They are generally underreported, with different rates in different health care systems. Methods: We conducted a 6-month survey of all primary admissions to the medical emergency department of a university hospital and assessed the rate, characteristics, avoidability, and marginal costs of ADRs. Results: A total of 7% of all admissions were mainly caused by ADRs. The most frequent were gastrointestinal bleeding (22.3%) and febrile neutropenia (14.4%). Anticancer drugs were involved in 22.7% of the cases, and anticoagulants, analgesics, and non-steroidal anti-inflammatory drugs in 8% each. Physicians had prescribed 70% of these drugs. Patients were predominantly treated in intermediate care units and ordinary wards. The mean cost per case amounted to CHF 3586+/-342, or a total of CHF 821204 over the 6-month-period (1 CHF=0.56 US$=0.87 Euro). A total of 67% were considered definitely imputable to drug effects and 32% were retrospectively regarded as avoidable. Conclusions: Interventions aimed at reducing the incidence of ADRs should be directed towards both patient education and physician training. This could save hospitals admissions and money, and could be used as an indicator of prescription quality.

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FSP27 (CIDEC in humans) is a protein associated with lipid droplets that downregulates the fatty acid oxidation (FAO) rate when it is overexpressed. However, little is known about its physiological role in liver. Here, we show that fasting regulates liver expression of Fsp27 in a time-dependent manner. Thus, during the initial stages of fasting a maximal induction of 800-fold was achieved, while during the later phase of fasting, Fsp27 expression decreased. The early response to fasting can be explained by a canonical PKA-CREB-CRTC2 signaling pathway since: i) CIDEC expression was induced by forskolin, ii) Fsp27 promoter activity was increased by CREB, and iii) Fsp27 expression was upregulated in the liver of Sirt1 knockout animals. Interestingly, pharmacological (etomoxir) or genetic (Hmgcs2 interference) inhibition of the FAO rate increases the in vivo expression of Fsp27 during fasting. Similarly, CIDEC expression was upregulated in HepG2 cells by either etomoxir or HMGCS2 interference. Our data indicate that there is a kinetic mechanism of auto-regulation between short- and long-term fasting, by which free fatty acids delivered to the liver during early fasting are accumulated/exported by FSP27/CIDEC, while over longer periods of fasting they are degraded in the mitochondria through the carnitine palmitoyl transferase (CPT) system.

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Increased production of reactive oxygen species (ROS) in mitochondria underlies major systemic diseases, and this clinical problem stimulates a great scientific interest in the mechanism of ROS generation. However, the mechanism of hypoxia-induced change in ROS production is not fully understood. To mathematically analyze this mechanism in details, taking into consideration all the possible redox states formed in the process of electron transport, even for respiratory complex III, a system of hundreds of differential equations must be constructed. Aimed to facilitate such tasks, we developed a new methodology of modeling, which resides in the automated construction of large sets of differential equations. The detailed modeling of electron transport in mitochondria allowed for the identification of two steady state modes of operation (bistability) of respiratory complex III at the same microenvironmental conditions. Various perturbations could induce the transition of respiratory chain from one steady state to another. While normally complex III is in a low ROS producing mode, temporal anoxia could switch it to a high ROS producing state, which persists after the return to normal oxygen supply. This prediction, which we qualitatively validated experimentally, explains the mechanism of anoxia-induced cell damage. Recognition of bistability of complex III operation may enable novel therapeutic strategies for oxidative stress and our method of modeling could be widely used in systems biology studies.

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PURPOSE: To evaluate the effect of a real-time adaptive trigger delay on image quality to correct for heart rate variability in 3D whole-heart coronary MR angiography (MRA). MATERIALS AND METHODS: Twelve healthy adults underwent 3D whole-heart coronary MRA with and without the use of an adaptive trigger delay. The moment of minimal coronary artery motion was visually determined on a high temporal resolution MRI. Throughout the scan performed without adaptive trigger delay, trigger delay was kept constant, whereas during the scan performed with adaptive trigger delay, trigger delay was continuously updated after each RR-interval using physiological modeling. Signal-to-noise, contrast-to-noise, vessel length, vessel sharpness, and subjective image quality were compared in a blinded manner. RESULTS: Vessel sharpness improved significantly for the middle segment of the right coronary artery (RCA) with the use of the adaptive trigger delay (52.3 +/- 7.1% versus 48.9 +/- 7.9%, P = 0.026). Subjective image quality was significantly better in the middle segments of the RCA and left anterior descending artery (LAD) when the scan was performed with adaptive trigger delay compared to constant trigger delay. CONCLUSION: Our results demonstrate that the use of an adaptive trigger delay to correct for heart rate variability improves image quality mainly in the middle segments of the RCA and LAD.

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BACKGROUND: Giant cell arteritis (GCA) is a systemic segmental vasculitis of unknown etiology, typically affecting elderly patients. Elevated erythrocyte-sedimentation rate (ESR) is usually found in such patients. PATIENTS AND METHODS: One hundred and twenty three patients underwent temporal artery biopsy in our institution between 1977 and 1995. Among them, 66 (53.7%) biopsies were positive (i.e. histologic findings were very suggestive of GCA). The clinical charts from all patients with positive biopsies were retrieved and 47 were eligible for our study (inadequate data in 19 cases). RESULTS: Seven of the 47 patients with positive biopsies (15%) had a normal ESR and 70% (33/47 cases) had neuro-ophthalmic complications including anterior ischemic optic neuropathy, central retinal artery occlusion, choroidal ischemia and extraocular muscle and/or cranial nerve palsy (III, IV, VI). No differences were found between the groups with normal or elevated ESR as 87.5% (6/7 cases) of the group with normal ESR exhibited neuro-ophthalmic complications. CONCLUSIONS: ESR was normal in 15% of our GCA patients and these patients had the same frequency of neuro-ophthalmic complications as the GCA patients with elevated ESR. Thus, our study does not support the previous concept that patients with higher ESR are more at risk for neuro-ophthalmic complications. GCA with normal ESR is not rare and such patients should be investigated with other blood studies (C-reactive protein) and with fluorescein angiography.

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Selostus: Maan muotoilun, kylvötavan ja siementiheyden vaikutus porkkanan satoon

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Several unit root tests in panel data have recently been proposed. The test developed by Harris and Tzavalis (1999 JoE) performs particularly well when the time dimension is moderate in relation to the cross-section dimension. However, in common with the traditional tests designed for the unidimensional case, it was found to perform poorly when there is a structural break in the time series under the alternative. Here we derive the asymptotic distribution of the test allowing for a shift in the mean, and assess the small sample performance. We apply this new test to show how the hypothesis of (perfect) hysteresis in Spanish unemployment is rejected in favour of the alternative of the natural unemployment rate, when the possibility of a change in the latter is considered.

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This paper tests for real interest parity (RIRP) among the nineteen major OECD countries over the period 1978:Q2-1998:Q4. The econometric methods applied consist of combining the use of several unit root or stationarity tests designed for panels valid under cross-section dependence and presence of multiple structural breaks. Our results strongly support the fulfilment of the weak version of the RIRP for the studied period once dependence and structural breaks are accounted for.

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How long induced moods last is a critical question for mood research but has been only poorly addressed. In particular, physiological parameters have been rarely included to assess the effectiveness of mood induction procedures. Adopting a dimensional model of mood, we investigated the persistence of four different moods (positive higharousal, positive low-arousal, negative high-arousal, negative lowarousal) induced by four film clips ("sport", "nature", "torture", "slum") during a 9-minute computer task. We measured subjective mood state (valence and arousal), respiration, skin conductance level (SCL), heart rate, and corrugator activity in 76 subjects. Viewing of the selected film clips induced the expected effects both subjectively and physiologically. Corrugator activity was higher at the end of the negative clips than the positive clips, and ventilation and SCL were higher for the arousing clips than for the less arousing clips. People who watched the negative clips still reported more negative valence after the computer task and also showed more facial frowning (cf. figure) and lower SCL during the task than people who watched the positive clips. No arousal effects persisted throughout the task. The results suggest that induced changes in the valence dimension of moods are maintained throughout an intervening task and are physiologically best reflected by corrugator activity and SCL, whereas induced changes in the arousal dimension dissipate quickly. The findings of this study enrich, first, our knowledge concerning the relationships between subjective feelings and their physiological substrate. Second, they inform us about the effectiveness of film clips as a mood induction instrument. Third and most important, they suggest that induced changes in valence last longer than induced changes in arousal. High-arousal moods can last for an extended period of time in daily life, but they seem to be short-lived when induced in the lab. An important methodological consequence is that investigating the effect of the arousal dimension of a person's mood induced in the lab may be only possible when the subsequent task is relatively short. Finally, the findings show which physiological measures may be useful in tracking mood states.

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This paper tests for real interest parity (RIRP) among the nineteen major OECD countries over the period 1978:Q2-1998:Q4. The econometric methods applied consist of combining the use of several unit root or stationarity tests designed for panels valid under cross-section dependence and presence of multiple structural breaks. Our results strongly support the fulfilment of the weak version of the RIRP for the studied period once dependence and structural breaks are accounted for.

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[cat] En aquest treball es presenta un model eclèctic que sistematitza la dinàmica de les crisis que s’autoconfimen, usant els principals aspectes de les tres tipologies dels models de crisis canviàries de tercera generació, amb la finalitat de descriure els fets que precipiten la renúncia al manteniment d’una paritat fixada. Les contribucions més notables són les implicacions per a la política econòmica, així com la pèrdua del paper del tipus de canvi com instrument d’ajust macroeconòmic, quan els efectes de balanç són una possibilitat real.

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Several unit root tests in panel data have recently been proposed. The test developed by Harris and Tzavalis (1999 JoE) performs particularly well when the time dimension is moderate in relation to the cross-section dimension. However, in common with the traditional tests designed for the unidimensional case, it was found to perform poorly when there is a structural break in the time series under the alternative. Here we derive the asymptotic distribution of the test allowing for a shift in the mean, and assess the small sample performance. We apply this new test to show how the hypothesis of (perfect) hysteresis in Spanish unemployment is rejected in favour of the alternative of the natural unemployment rate, when the possibility of a change in the latter is considered.