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OBJECTIVES: To seek associations between meteorological factors, concentrations of air pollutants or pollen, and an asthma epidemic which occurred in London on 24 and 25 June 1994 after a thunderstorm. DESIGN: Retrospective study of patients' accident and emergency department records, with bivariate and multivariate analysis of environmental factors and data collection for the two months surrounding the epidemic. SETTING: The accident and emergency department of St Mary's Hospital in west central London. SUBJECTS: 148 patients presenting with asthma between 1 June and 31 July 1994, of whom 40 presented in the 24 hours after the storm. RESULTS: The asthma epidemic was significantly associated with a drop in air temperature six hours previously and a high grass pollen concentration nine hours previously. Non-epidemic asthma was significantly associated with lightning strikes, increase in humidity or sulphur dioxide concentration, a drop in temperature or high rainfall the previous day, and a decrease in maximum air pressure or changes in grass pollen counts over the previous two days. CONCLUSIONS: New episodes of asthma during the epidemic on 24 and 25 June 1994 were associated with a fall in air temperature and a rise in grass pollen concentration. Non-epidemic asthma was significantly associated with a greater number of environmental changes. This may indicate that the patients with thunderstorm associated asthma were a separate population, sensitive to different environmental stimuli.  相似文献   

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Escape from fear (EFF) is a controversial paradigm according to which animals learn to actively escape a fear-eliciting conditioned stimulus (CS) if the escape response (Re) is paired with CS termination. Some theories posit that EFF learning is responsible for instrumental avoidance conditioning. However, EFF learning has typically been weaker than avoidance learning and difficult to reproduce. The authors examined EFF learning and memory with 2 atypical Res: rearing and nose-poking. The data suggest that rearing, but not nose-poking, can be learned as an instrumental EFF response. Further, EFF memory was response specific, aversively motivated, and controlled by the CS. Successful EFF learning also resulted in better long-term elimination of a passive fear reaction (freezing). Factors important for EFF experiments and theoretical considerations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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The K+ inwardly rectifier channel (KIR) is one of the two sub-units of the pancreatic islet ATP-sensitive potassium channel complex (I(KATP)), which has a key role in glucose-stimulated insulin secretion and thus is a potential candidate for a genetic defect in Type II (non-insulin-dependent) diabetes mellitus. We did a molecular screening of the KIR6.2 gene by single strand conformational polymorphism (SSCP) and direct sequencing in 72 French Caucasian Type II diabetic families. We identified three nucleotide substitutions resulting in three amino acid changes (E23K, L270V and 1337V), that have also been identified in other Caucasian Type II diabetic subjects. These variants were genotyped in French cohorts of 191 unrelated Type II diabetic probands and 119 normoglycaemic control subjects and association studies were done. The genotype frequencies of the L270V and 1337V variants were not very different between Type II diabetic subjects and control groups. In contrast, analysis of the E23K variant showed that the KK homozygocity was more frequent in Type II diabetic than in control subjects (27 vs 14%, p = 0.015). Analyses in a recessive model (KK vs EK/EE) tended to show a stronger association of the K allele with diabetes (p = 0.0097, corrected p-value for multiple testing < 0.02). The data for the E23K variant obtained here and those obtained from three other Caucasian groups studied so far were combined and investigated by meta-analysis. Overall, the E23K variant was found to be significantly associated with Type II diabetes (0.001 < or = p < or = .00106, corrected p-values for multiple testing p < or = 0.01). This study shows that KIR6.2 polymorphisms are frequently associated with Type II diabetes in French Caucasians. Furthermore, a meta-analysis combining different Caucasian groups suggests an significant role of KIR6.2 in the polygenic context of Type II diabetes.  相似文献   

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Centrally injected neuropeptide Y (NPY) is a potent stimulant of ingestive behavior capable of augmenting both food and fluid intake in fully satiated animals. To gain further insight into NPY's mechanism of action, we recorded patterns of licking behavior in rats drinking sweetened condensed milk solutions immediately after lateral ventricular injection of NPY (10 micrograms) or vehicle. In a separate study, we examined licking patterns after 23 h food deprivation (FD) that produced approximately the same total intake as NPY. Consistent with previous reports, we found NPY stimulated intake by increasing total ingestion time and total volume consumed during a 1-h test. Although NPY increased the number of bouts of licking and shortened pauses between bouts, it also decreased mean bout size, bout duration and within-bout lick rate (local rate). It had no significant effect on start latency or lick efficiency (licks/ml). Further analyses revealed that NPY attenuated satiety (reduced slope of lick-rate functions with session time) but had no significant effect on the beginning lick rate, a measure related to orosensory excitation. In contrast to NPY, FD increased both the beginning lick rate and individual bout size without changing either the mean number of bouts or the pause between bouts. In general, NPY stimulated an intermittent pattern of licking and delayed satiation whereas FD increased the initial rate of licking and the size of individual bouts without changing the basic licking pattern. The increase in initial lick rate suggests that FD, unlike NPY, enhances orosensory stimulation. These data compliment previous results showing that NPY increases the motivation to eat.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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