The Human Gonadotropin Releasing Hormone Type I Receptor Is a Functional Intracellular GPCR Expressed on the Nuclear Membrane

The mammalian type I gonadotropin releasing hormone receptor (GnRH-R) is a structurally unique G protein-coupled receptor (GPCR) that lacks cytoplasmic tail sequences and displays inefficient plasma membrane expression (PME). Compared to its murine counterparts, the primate type I receptor is inefficiently folded and retained in the endoplasmic reticulum (ER) leading to a further reduction in PME. The decrease in PME and concomitant increase in intracellular localization of the mammalian GnRH-RI led us to characterize the spatial distribution of the human and mouse GnRH receptors in two human cell lines, HEK 293 and HTR-8/SVneo. In both human cell lines we found the receptors were expressed in the cytoplasm and were associated with the ER and nuclear membrane. A molecular analysis of the receptor protein sequence led us to identify a putative monopartite nuclear localization sequence (NLS) in the first intracellular loop of GnRH-RI. Surprisingly, however, neither the deletion of the NLS nor the addition of the Xenopus GnRH-R cytoplasmic tail sequences to the human receptor altered its spatial distribution. Finally, we demonstrate that GnRH treatment of nuclei isolated from HEK 293 cells expressing exogenous GnRH-RI triggers a significant increase in the acetylation and phosphorylation of histone H3, thereby revealing that the nuclear-localized receptor is functional. Based on our findings, we conclude that the mammalian GnRH-RI is an intracellular GPCR that is expressed on the nuclear membrane. This major and novel discovery causes us to reassess the signaling potential of this physiologically and clinically important receptor

Entanglement enhancement for two spins assisted by two phase kicks

Background.Pseudomonas aeruginosa is a common cause of nosocomial infections, particularly in intensive care units (ICUs). The aim of this study was to characterize P. aeruginosa clinical isolates by comparing antimicrobial susceptibility patterns with the presence of plasmids and to establish the clonal relatedness by pulsed-field gel electrophoresis (PFGE) typing. Methods. The patients included those with isolation of P. aeruginosa hospitalized for more than 48 h in the ICU from April to May 1998. Environmental and staff cultures were obtained simultaneously. Minimal inhibitory concentrations, plasmid DNA profiles, and PFGE genomic patterns of enzyme restriction chromosomal DNA were compared. Results. Sixty P. aeruginosa isolates were obtained from 197 clinical specimens, 178 environmental samples, and 47 hand cultures of personnel. Antimicrobial resistance was as follows: tobramycin 100%; ticarcillin, cefotaxime, ceftriaxone, ceftazidime, and gentamicin 80%; cefepime 60%; amikacin, ticarcillin/clavulanate, imipenem, and meropenem 40%; piperacillin and norfloxacin 20%; carbenicillin 12%, and ciprofloxacin 0%. Plasmids were detected in 11 isolates (18%). PFGE typing showed that 23 isolates belonged to a common clone (pattern A), identified from five patients, two nurses, and 10 environmental samples. Ten isolates were grouped in four clusters and 27 isolates had unrelated genomic patterns. There was no relationship among DNA genomic patterns, plasmid profiles, and susceptibility patterns. Conclusions. PFGE demonstrated the existence of a common clone in a critical care area. Reinforcement of infection control measures is needed to avoid horizontal transmission and severe infections. Copyright " 2001 IMSS.",,,,,,"10.1016/S0188-4409(01)00267-3",,,"http://hdl.handle.net/20.500.12104/41261","http://www.scopus.com/inward/record.url?eid=2-s2.0-0034981240&partnerID=40&md5=b1c9d05e0380724563de18282e321139",,,,,,"3",,"Archives of Medical Research",,"23

Epidemiologic study of Pseudomonas aeruginosa in critical patients and reservoirs

Background.Pseudomonas aeruginosa is a common cause of nosocomial infections, particularly in intensive care units (ICUs). The aim of this study was to characterize P. aeruginosa clinical isolates by comparing antimicrobial susceptibility patterns with the presence of plasmids and to establish the clonal relatedness by pulsed-field gel electrophoresis (PFGE) typing. Methods. The patients included those with isolation of P. aeruginosa hospitalized for more than 48 h in the ICU from April to May 1998. Environmental and staff cultures were obtained simultaneously. Minimal inhibitory concentrations, plasmid DNA profiles, and PFGE genomic patterns of enzyme restriction chromosomal DNA were compared. Results. Sixty P. aeruginosa isolates were obtained from 197 clinical specimens, 178 environmental samples, and 47 hand cultures of personnel. Antimicrobial resistance was as follows: tobramycin 100%; ticarcillin, cefotaxime, ceftriaxone, ceftazidime, and gentamicin 80%; cefepime 60%; amikacin, ticarcillin/clavulanate, imipenem, and meropenem 40%; piperacillin and norfloxacin 20%; carbenicillin 12%, and ciprofloxacin 0%. Plasmids were detected in 11 isolates (18%). PFGE typing showed that 23 isolates belonged to a common clone (pattern A), identified from five patients, two nurses, and 10 environmental samples. Ten isolates were grouped in four clusters and 27 isolates had unrelated genomic patterns. There was no relationship among DNA genomic patterns, plasmid profiles, and susceptibility patterns. Conclusions. PFGE demonstrated the existence of a common clone in a critical care area. Reinforcement of infection control measures is needed to avoid horizontal transmission and severe infections. Copyright © 2001 IMSS