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31.
Pulmonary surfactant is a complex mixture of lipids and proteins that functions to keep alveoli from collapsing at the end of expiration. Dipalmitoylphosphatidylcholine has been identified as the most important component for lowering surface tension at the air-liquid interface. Hydrophobic surfactant apoproteins, SP-B and SP-C, play essential roles in the biophysical functions of the surfactant phospholipids. Hydrophilic surfactant apoproteins (SP-A and SP-D) that are members of C-type lectin superfamily, interact with phospholipids and glycolipids and modulate host defense functions in the lung. SP-A also plays an important role in regulating phospholipid homeostasis in the alveolar spaces. Recent advances in genetics and molecular biology have clarified the structure-function relationship of surfactant apoproteins. 相似文献
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The activity of rifabutin (LM 427) against Mycobacterium leprae was evaluated in armadillos inoculated earlier with human-derived M. leprae. Rifabutin was administered daily at a dose of 6 mg/kg body weight/day. The effect of rifabutin on M. leprae harvested from armadillos was determined by measuring the intracellular levels of ATP (an indicator of metabolic activity) of M. leprae and also their ability to multiply in the mouse footpads and in vitro in DH medium. Within 2 weeks of initiating the treatment, ATP levels declined to 21% of the original (pre-treatment level) and these M. leprae failed to multiply in the footpads of mice as well as in the in vitro culture system. This suggests that rifabutin was able to kill all M. leprae within 2 weeks. After 8 weeks the treatment was terminated and results showed that M. leprae from the treated armadillos remained non-viable in the mouse footpad system as well as in the in vitro system, indicating bactericidal action of rifabutin. The results suggest that rifabutin can be a substitute for rifampin in the leprosy multi-drug therapy regimen. 相似文献
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SJ Mihic Q Ye MJ Wick VV Koltchine MD Krasowski SE Finn MP Mascia CF Valenzuela KK Hanson EP Greenblatt RA Harris NL Harrison 《Canadian Metallurgical Quarterly》1997,389(6649):385-389
Volatile anaesthetics have historically been considered to act in a nonspecific manner on the central nervous system. More recent studies, however, have revealed that the receptors for inhibitory neurotransmitters such as gamma-aminobutyric acid (GABA) and glycine are sensitive to clinically relevant concentrations of inhaled anaesthetics. The function of GABA(A) and glycine receptors is enhanced by a number of anaesthetics and alcohols, whereas activity of the related GABA rho1 receptor is reduced. We have used this difference in pharmacology to investigate the molecular basis for modulation of these receptors by anaesthetics and alcohols. By using chimaeric receptor constructs, we have identified a region of 45 amino-acid residues that is both necessary and sufficient for the enhancement of receptor function. Within this region, two specific amino-acid residues in transmembrane domains 2 and 3 are critical for allosteric modulation of both GABA(A) and glycine receptors by alcohols and two volatile anaesthetics. These observations support the idea that anaesthetics exert a specific effect on these ion-channel proteins, and allow for the future testing of specific hypotheses of the action of anaesthetics. 相似文献
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OBJECTIVES: Disturbances in gastrointestinal function may result from disordered eating and may lead to increases in gastrointestinal (GI) symptoms. We compared GI symptoms in obese and non-obese binge eaters and non-binge eaters. METHODS: One hundred nineteen obese and 77 normal-weight females completed a questionnaire on bowel symptoms and binge eating behaviors for the previous 3 months. Based on binge behaviors and body mass index (> 30 kg/m2), individuals were grouped as obese binge eaters (n = 73), obese non-binge eaters (n = 43), non-obese binge eaters (n = 14), and normal-weight controls (n = 61). RESULTS: Obese binge eaters reported more upper GI symptoms than normal controls or obese non-binge eaters (p < 0.001). Compared with normal controls, nausea, vomiting, and bloating was 2-4 times more prevalent in both binge eating groups. Indigestion was more prevalent in both obese groups. Obese binge eaters reported more lower GI symptoms than normal-weight controls (p < 0.05). Binge eating in both weight groups was associated with more frequent abdominal pain and dyschezia. Obesity was associated with more frequent constipation, diarrhea, straining, and flatus, whether or not subjects reported binge eating. Chi-square showed a significant association between obesity, binge eating, and symptoms of irritable bowel syndrome, using the Manning criteria. CONCLUSIONS: Specific GI symptoms were associated with binge eating and obesity. Overall, symptoms were more prevalent and more severe in obese binge eaters. The high prevalence of GI symptoms in obese patients who indulge in binge eating should be considered in their evaluation and treatment. 相似文献
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This report describes a case of Becker muscular dystrophy presenting with recurrent symptomatic wide complex tachycardia. Electrophysiologic testing demonstrated the mechanism to be bundle branch reentry ventricular tachycardia. It is important to consider this potential mechanism in patients with ventricular arrhythmias who have this particular clinical entity, since radiofrequency catheter ablation can represent a curative treatment. 相似文献