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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
962.
da Silva LG Mottin CC Souza DO Portela LV Braga CW Vargas CB Padoin AV Martinez D Dias RD 《Obesity surgery》2008,18(8):993-999
BACKGROUND: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is considered a comorbidity associated with morbid obesity, mainly because of the large neck circumference. Depending on its severity, OSAHS can interfere in many homeostasis systems, for example, the central nervous system (CNS). Neuron-specific enolase (NSE) and S100B protein derived from astrocytes are considered sensitive biochemical markers of cerebral injury. We evaluated serum S100B and NSE levels in this study with the aim of detecting possible cerebral injury as a consequence of OSAHS. METHODS: This was a transverse study with data from 25 morbidly obese patients with OSAHS. Blood samples were collected before and after polysomnography (PSG) to determine S100B and NSE protein levels. We also analyzed data evaluating depression and excessive daytime sleepiness. RESULTS: S100B levels were higher after [0.029 (0.010-0.199) mg/l] compared to before [0.010 (0.010-0.025) mg/l] on PSG (P = 0.002). S100B levels were expressed as means and IQ25-IQ75. NSE levels did not show significant differences before and after PSG. CONCLUSION: Our study shows a significant increase in S100B level after PSG compared to before. This suggests that there is a CNS astrocyte reaction because of possible cerebral hypoxemia in morbidly obese patients with OSAHS. 相似文献
963.
Chassin C Vimont S Cluzeaud F Bens M Goujon JM Fernandez B Hertig A Rondeau E Arlet G Hornef MW Vandewalle A 《Journal of the American Society of Nephrology : JASN》2008,19(12):2364-2374
Uropathogenic Escherichia coli (UPEC) are the most frequent causes of urinary tract infections and pyelonephritis. Renal medullary collecting duct (MCD) cells are the intrarenal site to which UPEC strains prefer to adhere and initiate an inflammatory response, but the ability of UPEC strains to translocate across impermeant MCD cells has not been demonstrated definitively. Here, several UPEC strains adhered to the apical surface and translocated across confluent murine inner MCD cells grown on filters. UPEC strains expressing cytolytic and vacuolating cytotoxins disrupted the integrity of cell layers, whereas noncytolytic UPEC strains passed through the cell layers without altering tight junctions. Apical-to-basal transcellular translocation was dramatically reduced after extinction of Toll-like receptor 4 (TLR4) and the lipid raft marker caveolin-1 by small interfering RNA. Furthermore, disruption of lipid raft integrity by filipin III and methyl-beta-cyclodextrin significantly reduced both the transcellular translocation of UPEC across murine inner MCD cell layers and the stimulation of proinflammatory mediators. Bacterial translocation was also significantly reduced in primary cultures of TLR4-deficient mouse MCD cells compared with MCD cells from wild-type mice. Benzyl alcohol, an anesthetic that enhances membrane fluidity, favored the recruitment of caveolin-1 in lipid rafts and increased the translocation of UPEC across cultured TLR4-deficient MCD cells. These findings demonstrate that the transcellular translocation of UPEC strains across impermeant layers of MCD cells may occur through lipid rafts via a TLR4-facilitated process. 相似文献
964.
Delahousse M Chaignon M Mesnard L Boutouyrie P Safar ME Lebret T Pastural-Thaunat M Tricot L Kolko-Labadens A Karras A Haymann JP 《Journal of the American Society of Nephrology : JASN》2008,19(4):798-805
Increased aortic stiffness is a major factor responsible for the high cardiovascular mortality in patients with end-stage renal disease, but the impact of kidney transplantation on recipient aortic stiffness remains poorly defined. The use of expanded-criteria kidney donors is associated with decreased recipient survival compared with the use of standard-criteria donors, although the underlying mechanisms are incompletely understood. It was hypothesized that donor characteristics may affect recipient aortic stiffness, which may contribute to cardiovascular mortality in these patients. Aortic stiffness was evaluated by measurement of carotid-femoral pulse wave velocity in 74 cadaveric kidney recipients at 3 and 12 mo after transplantation. At 3 mo, aortic stiffness was associated exclusively with recipient-related factors: Age, gender, and mean BP. At 12 mo, age of the donor kidney emerged as an additional determinant. The change in aortic stiffness between 3 and 12 mo strongly correlated with donor age; stiffness improved in recipients of young kidneys (first tertile of donor age) and worsened in recipients of older kidneys (upper tertile of donor age). At 12 mo, the carotid-femoral pulse wave velocity was >1 m/s higher in recipients of the oldest kidneys than in the recipients of younger kidneys. The association between donor age and aortic stiffness was independent of recipient age, gender, mean BP, pretransplantation dialysis duration, conventional cardiovascular risk factors, medication, posttransplantation events, and GFR. These results demonstrate that the impact of kidney transplantation on recipient aortic stiffness is dependent on donor age and suggest that ongoing damage to large arteries might contribute to the mechanism underlying the association of old-donor kidneys and increased cardiovascular mortality. 相似文献
965.
Guimaraes-Filho F Tan D Braga J Rodrigues A Waib P Matsubara B 《The American journal of cardiology》2007,100(8):1303-1306
Doppler echocardiography has been used for the diagnosis of anthracycline-induced cardiotoxicity. However, few data are available that include asymptomatic children previously treated with a low cumulative dose of this drug and therefore have a low risk of cardiac dysfunction. The aim of this study was to evaluate after-exercise cardiac function in asymptomatic children previously treated with a low cumulative dose of anthracycline and no clinical or laboratory evidence of cardiotoxicity. Doppler echocardiography was performed before and immediately after physical exercise in 29 children aged 5 to 17 years (anthracycline [ADRIA] group). All had finished cancer treatment with anthracycline derivatives for > or =1 year (cumulative dose 100 mg/m(2)). Results were compared with those from age- and gender-matched healthy children (control group; n = 26) using the Mann-Whitney rank test. Exercise-induced cardiac function changes within groups were analyzed using Wilcoxon's signed-rank test. Exercise induced significant increases in left ventricular systolic function indexes in both groups. However, the ADRIA group had significantly lower changes in left ventricular ejection fraction (ADRIA group 0.71 +/- 0.02 vs 0.80 +/- 0.04 and control group 0.71 +/- 0.02 vs 0.89 +/- 0.05, p = 0.0017) and end-systolic stress-volume index (ADRIA group 4.59 +/- 0.69 vs 6.4 +/- 2.0 g.cm(-2)/ml.m(-2) and control group 5.49 +/- 0.98 vs 11.54 +/- 2.86 g.cm(-2)/ml.m(-2); p <0.0001), indicating decreased functional systolic reserve. In conclusion, asymptomatic children previously treated with low cumulative doses of anthracycline had decreased functional systolic reserve evidenced by exercise, suggesting a nonclinically manifested cardiotoxicity. 相似文献
966.
Bernabé J Julia-Guilloteau V Denys P Chartier-Kastler E Alexandre L Peeters M Giuliano F 《BJU international》2008,102(9):1162-1167
OBJECTIVES
To characterize the effect of acute unilateral and bilateral lesion of the pelvic and pudendal nerves, and nerves innervating the iliococcygeous and pubococcygeous muscles during sneezing in anaesthetized female cats, on intravesical pressure (IVP), urethral pressure (UPs) and external urethral sphincter (EUS) activity.MATERIALS AND METHODS
In seven anaesthetized female cats UPs along the urethra (UPs1–4) and IVPs were recorded in the emptied bladder during sneezing before and after unilateral and then bilateral peripheral neural lesions. UPs were measured using microtip transducer catheters with UP4 positioned in the distal urethra where the EUS is located. Urine leakage was also noted, after urethral catheter removal and bladder filling.RESULTS
During sneezing, in intact cats, the magnitude of UP4 was larger than those of IVP and UPs1–3. The area under the curve of both anal sphincter and EUS electromyography was increased. There was no urine leakage. After unilateral neural lesions, the mean magnitude of response was similar all along the urethra and in the bladder. The distal UP response was significantly lower than that recorded in intact cats. In addition, there was urine leakage in six of the seven cats. Bilateral neural lesions caused permanent urine leakage and significant decreases in all the UP responses.CONCLUSION
In female cats, during sneezing, neurally driven reflex contractions of EUS leading to an increase in distal UP contribute to active urethral closure mechanisms and ensure urinary continence. 相似文献967.
Pelzer AE Colleselli D Bektic J Steiner E Ramoner R Mitterberger M Schwentner C Schaefer G Ongarello S Bartsch G Horninger W 《BJU international》2008,101(7):822-825
OBJECTIVE
To assess the pathological features of Gleason score 6 prostate cancers after radical prostatectomy in the low (<4 ng/mL) and intermediate range of prostate‐specific antigen level (4–10 ng/mL), as such prostate cancers are considered to be well differentiated tumours with a low risk for recurrence after therapy.PATIENTS AND METHODS
In all, 1354 patients with T1c prostate cancer and PSA levels of <10.0 ng/mL had a radical retropubic prostatectomy. Patients with Gleason score 6 tumours were divided into two groups, those with PSA levels of <4 and 4.0–10.0 ng/mL. Extracapsular extension, positive surgical margins, biochemical recurrence (BCR) and mean time to BCR were evaluated.RESULTS
Of the 1354 patients, there were 437 (32.3%) with Gleason score 6 prostate cancers. Patients in the low PSA group had less extraprostatic disease than those with a higher level (5.9% vs 14.5%) and both groups had an almost equal proportion of positive surgical margins (9.4% vs 11.0%). In the low PSA group there was statistically significantly shorter BCR than in the high PSA group, with a mean time to BCR of 1.7 vs 3.1 years.CONCLUSIONS
These results show a statistically significantly higher rate of extraprostatic disease and earlier BCR in men with a high than a low PSA level even in Gleason score 6 prostate cancer. As the rate of BCR and extracapsular extension are significantly related to prostate cancer mortality, these findings further support the concept of screening using low PSA levels. 相似文献968.
969.
Alexandre Gouzy Claire Healy Katherine A. Black Kyu Y. Rhee Sabine Ehrt 《Proceedings of the National Academy of Sciences of the United States of America》2021,118(32)
Acidic pH arrests the growth of Mycobacterium tuberculosis in vitro (pH < 5.8) and is thought to significantly contribute to the ability of macrophages to control M. tuberculosis replication. However, this pathogen has been shown to survive and even slowly replicate within macrophage phagolysosomes (pH 4.5 to 5) [M. S. Gomes et al., Infect. Immun. 67, 3199–3206 (1999)] [S. Levitte et al., Cell Host Microbe 20, 250–258 (2016)]. Here, we demonstrate that M. tuberculosis can grow at acidic pH, as low as pH 4.5, in the presence of host-relevant lipids. We show that lack of phosphoenolpyruvate carboxykinase and isocitrate lyase, two enzymes necessary for lipid assimilation, is cidal to M. tuberculosis in the presence of oleic acid at acidic pH. Metabolomic analysis revealed that M. tuberculosis responds to acidic pH by altering its metabolism to preferentially assimilate lipids such as oleic acid over carbohydrates such as glycerol. We show that the activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is impaired in acid-exposed M. tuberculosis likely contributing to a reduction in glycolytic flux. The generation of endogenous reactive oxygen species at acidic pH is consistent with the inhibition of GAPDH, an enzyme well-known to be sensitive to oxidation. This work shows that M. tuberculosis alters its carbon diet in response to pH and provides a greater understanding of the physiology of this pathogen during acid stress.Tuberculosis (TB) is a chronic disease mostly affecting the lungs and, despite the availability of a vaccine and antibiotic therapy, remains the leading cause of death due to a single bacterium. An estimated 2 billion people are thought to be infected with Mycobacterium tuberculosis, the causative agent of TB, with 10 million new infections each year and 1 million deaths (1). M. tuberculosis success as a pathogen can be attributed to its ability to adapt and persist within the host. This intracellular pathogen replicates within macrophages and must be able to withstand host-imposed stresses as well as gain access to nutrients to survive and proliferate. M. tuberculosis has been observed inside lipid-rich lesions during infection in humans and in animal models of TB (2, 3). Its genome contains an extensive number of redundant genes dedicated to β-oxidation necessary for lipid breakdown, indicating the importance of lipid catabolism (4). In addition to β-oxidation, lipid utilization depends on two key enzymes, isocitrate lyase (ICL) required for the glyoxylate shunt and phosphoenolpyruvate carboxykinase (PEPCK) catalyzing the first committed step of gluconeogenesis. Mutants lacking either ICL or PEPCK cannot grow with lipids as a sole carbon source and are severely attenuated in the TB mouse model (5–7). While M. tuberculosis can simultaneously use several different carbon sources to grow in vitro (8), lipids seem to be the primary source of carbon during infection (5, 7, 9–11). Whether this is because glycolytic carbon sources are scarce or inaccessible or because M. tuberculosis requires lipids to grow during infection is unknown.Despite its ability to block phagosome–lysosome fusion, a notable fraction of phagocytosed M. tuberculosis is rapidly trafficked toward acidified compartments, and this proportion increases upon macrophage activation by T cell produced interferon-γ (IFN-γ) (12–14). Moreover, lung tissues from TB patients were found to have a median pH of pH 5.5 (15) supporting that M. tuberculosis faces acid stress during its infectious cycle in humans. M. tuberculosis can survive at a pH as low as pH 4.5 by maintaining its intracellular pH close to neutral at least in part through sustained peptidoglycan hydrolysis (16, 17). While the identification of mechanisms that enable M. tuberculosis to survive at acidic pH has taken much attention, how the pathogen adapts to an acidified environment to grow and promote disease remains ill defined. At acidity lower than pH 5.8, M. tuberculosis enters a nonreplicating state in vitro (18). This growth arrest at mildly acidic pH is surprising considering that the bacterium likely replicates in more acidic environments during infection.The media used to culture mycobacteria contain glycerol and glucose as main carbon sources. Previous work demonstrated that growth of M. tuberculosis at acidic pH is improved by changing the carbon source (18, 19). Pyruvate promoted growth of M. tuberculosis at pH 5.7 (19) indicating that growth at acidic pH is regulated by available carbon sources. Because lipids appear to be the primary carbon source M. tuberculosis utilizes to grow in vivo (5, 7, 9–11), we hypothesized that providing host-relevant carbon sources to M. tuberculosis, such as lipids, would serve as a more physiologically relevant model to examine how M. tuberculosis responds to acidic pH. Here, we demonstrate that providing oleic acid (OA) (and other host-relevant lipids) as a carbon source to M. tuberculosis, resulted in sustained growth in acidic cultures at pH 5.5 and below. We applied metabolomics, genetic, and biochemical approaches to investigate this pH-driven use of lipids to support growth. Our work helps explain the dependence of M. tuberculosis on lipids as a primary carbon source during infection and demonstrates that M. tuberculosis is well adapted to the acidic environments it encounters during infection; in fact, it is not only able to maintain its neutral intrabacterial pH, as previously reported, but can replicate in acidic conditions similar to those within phagolysosomes. 相似文献
970.
GlialCAM, an immunoglobulin-like cell adhesion molecule is expressed in glial cells of the central nervous system 总被引:1,自引:0,他引:1
Favre-Kontula L Rolland A Bernasconi L Karmirantzou M Power C Antonsson B Boschert U 《Glia》2008,56(6):633-645
Using structure based genome mining targeting vascular endothelial and platelet derived growth factor immunoglobulin (Ig) like folds, we have identified a sequence corresponding to a single transmembrane protein with two Ig domains, which we cloned from a human brain cDNA library. The cDNA is identical to hepatocyte cell adhesion molecule (hepaCAM), which was originally described as a tumor suppressor gene in liver. Here, we show that the protein is predominantly expressed in the mouse and human nervous system. In liver, the expression is very low in humans, and is not detected in mice. To identify the central nervous system (CNS) regions and cell types expressing the protein, we performed a LacZ reporter gene assay on heterozygous mice in which one copy of the gene encoding the novel protein had been replaced with beta-galactosidase. beta-galactosidase expression was prominent in white matter tracts of the CNS. Furthermore, expression was detected in ependymal cells of the brain ventricular zones and the central canal of the spinal cord. Double labeling experiments showed expression mainly in CNPase positive oligodendrocytes (OL). Since the protein is predominantly expressed in the CNS glial cells, we named the molecule glial cell adhesion molecule (GlialCAM). A potential role for GlialCAM in myelination was supported by its up-regulation during postnatal mouse brain development, where it was concomitantly expressed with myelin basic protein (MBP). In addition, in vitro, GlialCAM was observed in various developmental stages of OL and in astrocytes in processes and at cell contact sites. In A2B5 positive OL, GlialCAM colocalizes with GAP43 in OL growth cone like structures. Overall, the data presented here indicate a potential function for GlialCAM in glial cell biology. 相似文献