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951.
Background
Proteins linking intermediate filaments to other cytoskeletal components have important functions in maintaining tissue integrity and cell shape. 相似文献952.
BACKGROUND: Primary central mucoepidermoid carcinoma of jaws is a rare lesion comprising 2-3% of all mucoepidermoid carcinomas reported in literature. CASE PRESENTATION: The case presented here illustrates the hypothesis that its specific pathogenesis is unknown. CONCLUSIONS: Mucoepidermoid carcinoma of the jaw is a rare tumour of unknown aetiology. Although about a 100 cases has been reported in literature, the speculation on its aetiopathogenesis has mainly centred on the pluripotential capabilities of the epithelial lining of odontogenic cysts. 相似文献
953.
Differences between sexes in physiological performance have received little attention in animals. We tested for sex differences in maximum sprint speed and maximal exertion over a range of temperatures in a population of Platysaurus intermedius wilhelmi lizards. We also examined sex-based differences in selected temperature range, mean field body temperatures (T(b)), and thermal activity limits. Finally, we conducted field studies to quantify male and female responses to a potential predator, which may be affected by their respective performance capabilities. Males were faster than females at all temperatures, and body size had no significant effect on sprint speeds. Males and females also selected similar T(b)'s when placed in a thermal gradient, but in the field, male lizards' T(b)'s were different from those of the females. However, predicted sprint speeds for males and females at their field T(b)'s are similar. No significant differences were found between males and females with regard to maximal exertion. When approached in the field, adult male lizards took refuge significantly earlier than did adult females and also fled over shorter distances, suggesting that females rely on crypsis as an escape strategy. 相似文献
954.
The effect of modified atmospheres on the survival of the eggs of four storage mite species 总被引:2,自引:0,他引:2
The results of a laboratory investigation into the effects of modified atmospheres (MA) on the eggs of mite pests of grain and cheese are presented. Four species of astigmatid mite were tested; Acarus farris (Oudemans). A. siro L., Lepidoglyphus destructor (Schrank) and Tyrophagus longior (Gervais). All are found in many habitats including grain and cheese stores. Three low oxygen (O2) MA mixtures were used, based on carbon dioxide (CO2), nitrogen (N2) or simulated burner gas (0.5 or 2% O2, 10% CO2, balance N2) plus 60% CO2 in air (8% O2). The mites were exposed at 15 degrees C and 80% r.h., a combination of conditions that occurs at the surface of stored grain during the autumn which promotes mite population growth. The exposure periods required to prevent egg hatch for each species in every mixture are given. Tyrophagus longior was the most tolerant species, followed by A. siro and A. farris, with L. destructor the most susceptible. Burner gas was the most effective mixture overall with 0.5% O2 but with an increase in the O2 level to 2% for all the mixtures, CO2 became the more effective control agent. With 60% CO2 in air some loss of efficacy was observed against the three most tolerant species and even more so for L. destructor. Sublethal exposures to MAs for at least 4 days in L. destructor, 6 days in A. farris and A. siro and 8 days for T. longior caused a delay in egg hatch. 相似文献
955.
Halberg F Cornélissen G Stoynev A Ikonomov O Katinas G Sampson M Wang Z Wan C Singh RB Otsuka K Sothern RB Sothern SB Sothern MI Syutkina EV Masalov A Perfetto F Tarquini R Maggioni C Kumagai Y Siegelova J Fiser B Homolka P Dusek J Uezono K Watanabe Y Wu J Prikryl P Blank M Blank O Sonkowsky R Schwartzkopff O Hellbrügge T Spector NH Baciu I Hriscu M Bakken E 《Neuro endocrinology letters》2003,24(6):479-498
956.
957.
Overeem S Kok SW Lammers GJ Vein AA Frölich M Meinders AE Roelfsema F Pijl H 《American journal of physiology. Endocrinology and metabolism》2003,284(3):E641-E647
Narcolepsy is a sleep disorder caused by impaired hypocretin (orexin) neurotransmission. Growth hormone (GH) secretion may be altered in narcolepsy for various reasons. Slow-wave sleep episodes, which are closely associated with GH-secretory events, are more randomly dispersed over 24 h in narcoleptics. Furthermore, hypocretins may inhibit pituitary GH release. We assessed the function of the somatotropic axis in narcolepsy by deconvolving 24-h (10-min sampling interval) plasma GH concentration profiles in seven hypocretin-deficient narcoleptic patients and in seven healthy controls matched for age, sex, and body weight. Both basal and pulsatile GH secretion rate and secretagogue-induced GH release were similar in patients and controls. However, narcoleptics secreted approximately 50% of their total production during the daytime, whereas controls secreted only 25% during the day. Also, the GH output pattern of narcoleptics was significantly less regular. We propose that hypocretin deficiency disrupts the circadian distribution of hypothalamic GH-releasing hormone release in narcoleptic patients to simultaneously cause daytime GH release and promote their propensity to fall asleep during the day. 相似文献
958.
Pamir N Lynn FC Buchan AM Ehses J Hinke SA Pospisilik JA Miyawaki K Yamada Y Seino Y McIntosh CH Pederson RA 《American journal of physiology. Endocrinology and metabolism》2003,284(5):E931-E939
The incretins glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are gut hormones that act via the enteroinsular axis to potentiate insulin secretion from the pancreas in a glucose-dependent manner. Both GLP-1 receptor and GIP receptor knockout mice (GLP-1R(-/-) and GIPR(-/-), respectively) have been generated to investigate the physiological importance of this axis. Although reduced GIP action is a component of type 2 diabetes, GIPR-deficient mice exhibit only moderately impaired glucose tolerance. The present study was directed at investigating possible compensatory mechanisms that take place within the enteroinsular axis in the absence of GIP action. Although serum total GLP-1 levels in GIPR knockout mice were unaltered, insulin responses to GLP-1 from pancreas perfusions and static islet incubations were significantly greater (40-60%) in GIPR(-/-) than in wild-type (GIPR(+/+)) mice. Furthermore, GLP-1-induced cAMP production was also elevated twofold in the islets of the knockout animals. Pancreatic insulin content and gene expression were reduced in GIPR(-/-) mice compared with GIPR(+/+) mice. Paradoxically, immunocytochemical studies showed a significant increase in beta-cell area in the GIPR-null mice but with less intense staining for insulin. In conclusion, GIPR(-/-) mice exhibit altered islet structure and topography and increased islet sensitivity to GLP-1 despite a decrease in pancreatic insulin content and gene expression. 相似文献
959.
Phadke SM Islam K Deslouches B Kapoor SA Beer Stolz D Watkins SC Montelaro RC Pilewski JM Mietzner TA 《Peptides》2003,24(8):1099-1107
Lentivirus lytic peptides (LLPs) are derived from HIV-1 and have antibacterial properties. LLP derivatives (eLLPs) were engineered for greater potency against Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA). Minimum bactericidal concentration (MBC) was determined in low and physiologic salt concentrations. MBC was decreased against SA and equivalent against PA in physiologic salt when compared to the parent compound LLP1. In a novel cystic fibrosis (CF) airway cell model, one derivative, WLSA5, reduced the number of adherent PA and only moderately affected CF cell viability. Overall, eLLPs are selectively toxic to bacteria and may be useful against CF airway infections. 相似文献
960.
Efficient use of a 'dead-end' GA 5' splice site in the human fibroblast growth factor receptor genes 下载免费PDF全文
We have investigated use of a conserved non-canonical GA 5' splice site present in vertebrate fibroblast growth factor receptor (FGFR) genes. Despite previous studies suggesting that GA at the beginning of an intron is incompatible with splicing, we observe efficient utilization of this splice site for human FGFR1 gene constructs. We show that use of the GA splice site is dependent on both a conventional splice site six nucleotides upstream and sequence elements within the downstream intron. Furthermore, our results are consistent with competition between the tandem 5' splice sites being mediated by U6 snRNP, rather than U1 snRNP. Thus the GA 5' splice site represents an extension of the adjacent conventional 5' splice site, the first natural example of such a composite 5' splice site. 相似文献