缺血预处理对大鼠骨骼肌缺血再灌注损伤时Bax基因蛋白表达影响的实验研究

探讨缺血预处理对大鼠骨骼肌缺血再灌注损伤的可能影响,特别是对Bax基因表达的影响.用免疫组化方法检测并观察大鼠后肢止血带缺血4 h后再灌注4、24、48 h后和先经预缺血处理后再灌注4、24 h后Bax基因蛋白在肌细胞中的表达情况.结果表明缺血4 h(A组)肌细胞出现Bax蛋白表达,24h后(B组)表达量显增加,48h后(C组)无表达.缺血预处理后再灌注4 h后(D组)肌细胞内无Bax蛋白表达,再灌注24 h后(E组)Bax蛋白表达量非常显著地低于B组.Bax基因参与了骨骼缺血再灌注损伤的病理过程,其蛋白表达量与组织损伤程度密切相关,经缺血预处理可以下调Bax基因蛋白的表达水平、或是抑制其合成,使肌细胞存活而发挥其保护作用.     

Helicobacter pylori in tumor tissues of patients with advanced gastric adenocarcinoma: high prevalence but failure to detect integration

Helicobacter pylori has been known to be associated with gastric adenocarcinoma by case control studies. However, significant portion of patients with gastric carcinoma are negative for H. pylori by serological test. To further detect the presence of H. pylori infection in serum and tissue of patients with gastric adenocarcinoma, paired tissues and serum samples from 32 patients with gastric adenocarcinoma were tested. Antibodies to H. pylori were tested by an enzyme linked immunosorbent assay (ELISA) and a Western blot analysis. H. pylori in tumor and non-tumor parts of gastric tissues were examined by histology and polymerase chain reaction (PCR). For serum antibody, eighteen (56%) of these patients were positive by ELISA while 24 (75%) were positive by Western blot. For tissue H. pylori genome, 14 were positive by histology while 28 (87%) were positive by PCR. Southern blot analysis of both tumor and non-tumor tissues revealed no evidence of integration of H. pylori DNA in the human genomes. These results suggest that H. pylori infection can be detected in most patients with gastric adenocarcinoma, and PCR and Western blot can further identify seronegative patients.     

Membrane ionic currents and properties of freshly dissociated rat brainstem neurons

It is well known that neuronal firing properties are determined by synaptic inputs and inherent membrane functions such as specific ionic currents. To characterize the ionic currents of brainstem cardio-respiratory neurons, cells from the hypoglossal (XII) nucleus and the dorsal motor nucleus of the vagus (DMX) were freshly dissociated and membrane ionic currents were studied under whole-cell voltage and current clamp. Both of these neurons showed a TTX-sensitive Na⁺ current with a much larger current density in XII than DMX neurons. This Na⁺ current had two (fast and slow) distinct inactivation decay components. The ratio of the magnitudes of the fast to slow component was roughly two-fold greater in DMX than in XII cells. Both DMX and XII neurons also showed a high voltage-activated Ca²⁺ current, but this current density was significantly greater (three-fold) in DMX than XII neurons. A relatively small amount of low-voltage activated Ca²⁺ current was also observed in DMX neurons, but not in the majority of XII cells. A transient and a sustained outward current components were observed in DMX cells, but only sustained currents were present in XII neurons. These outward currents had a reversal potential of about − 70 mV with 3 mM external K⁺ and −30 mV with 25 mM K⁺, and substitution of K⁺ with cesium and tetraethylammonium suppressed more than 90% the outward currents, indicating that most outward currents were carried by K⁺. The transient outward current consisted of two components with onesensitive to 4-aminopyridine and the other to intracellular Ca²⁺. In XII neurons, BRL 38227 (lemakalim), an ATP-sensitive K⁺ (K_ATP) channel activator, increased the sustained K⁺ currents by 10% of control, and glibenclamide, a K_ATP channel blocker, decreased the sustained K⁺ currents by 20%. Evidence for the presence of an inward rectifier K⁺ current was also obtained from both XII and DMX neurons. These results on XII and DMX neurons indicate that (1) the methods used to dissociate neurons provide a useful means to overcome voltage clamp technical difficulties; (2) ion channel characteristics such as density and biophysical properties of DMX neurons are very different from those of XII neurons; and (3) several newly discovered membrane ionic currents are present in these cells.     

HLA and hypocretin studies in Korean patients with narcolepsy

STUDY OBJECTIVES: Very few studies have evaluated narcolepsy in Asian countries, outside of Japan. Our goal was to study narcolepsy at the genetic, clinical and pathophysiological level in Korea. DESIGN: Prospective study of consecutive patients and age matched controls. Clinical data ascertained from the Stanford Sleep Inventory, Polysomnography and MSLT data, as well as clinical notes. High resolution DRB1 and DQB1 typing in all subjects and studies of CSF hypocretin-1 was also evaluated in a subset of patients. PARTICIPANTS AND SETTING: 20 patients diagnosed at St. Vincent and Korea University Hospitals (Seoul, Korea). 21 Korean control subjects. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: For narcoleptic subjects, mean age was 28.2 years old and 45% were female. Mean BMI was 23.9+/-3.4 kg/m2, a significantly higher value than that expected in an age- and sex-matched sample (p<0.01). All patients had sleepiness and cataplexy while the prevalence of other symptoms ranged from 60-75%. All but 2 subjects were HLA-DR15 (DR2), DQB1*0602 positive (90%). This high DQB1*0602 percentage compared with 24% DQB1*0602 positivity in 21 control Koreans. Protective effects were observed for the DQB1*0601 and DRB1*0406 alleles, Hypocretin (orexin) CSF studies were also performed in 6 cataplectic subjects, all of which had undetectable CSF hypocretin levels. Two of these subjects had started narcolepsy less than 1 year before analysis yet had undetectable hypocretin levels. CONCLUSION: These results illustrate the similarity of narcolepsy-cataplexy in Korea in comparisons with other more studied populations. We also identified a new potential HLA protective subtype, HLA-DRB1*0406.     

Towards an in vitro model for acute hemorrhagic conjunctivitis: cytokine-mediated vascular endothelial cell activation triggered by enterovirus type 70 infection.

BACKGROUND: Little is known of the pathogenetic mechanisms of enterovirus type 70 (EV70), a causative agent of acute hemorrhagic conjunctivitis. However, virus- or cytokine-induced perturbation of vascular endothelial cells are potential triggering events. OBJECTIVE: To determine whether EV70 infection of human umbilical vascular endothelial cells (HUVECs) and human corneal epithelial cells (HCEs) causes the release of vasoactive cytokines, capable of triggering vascular endothelial cell activation. STUDY DESIGN: Susceptibility of cultured HUVECs and HCEs to EV70 was tested by observing the appearance of cytopathic effect or immunoprecipitation of viral protein in infected cells. The culture fluids from the virus-infected cells were tested for their ability to stimulate the expression of intercellular adhesion molecule-1 (ICAM-1) on uninfected HUVECs. Anti-cytokine antibodies were used to identify ICAM-1-activating cytokine(s). RESULTS: Both HUVECs and HCEs were susceptible to EV70 infection. Culture fluids from EV70-infected HUVECs and HCEs stimulated ICAM-l expression on uninfected HUVECs, which was completely blocked by anti-interleukin-1alpha (IL-1alpha) antibody but not by interleukin-1beta (IL-1beta) or anti-tumor necrosis factor alpha (TNFalpha) antibodies. CONCLUSION: This study provides the first evidence of EV70 infection of both HCEs and HUVECs, and furthermore, identifies IL-1alpha as the predominant endothelial cell-activating factor produced by EV70-infected cells. Since endothelial cell activation is often an initiating step towards vascular permeability and/or inflammation, the perturbation of endothelial cell function through EV70 induced IL-1alpha is thus a potential contributory factor in the pathogenesis of EV70-associated hemorrhagic conjunctivitis.     

Epidemiologic relationship between fluoroquinolone-resistant Salmonella enterica Serovar Choleraesuis strains isolated from humans and pigs in Taiwan (1997 to 2002)

The emergence of ciprofloxacin-resistant Salmonella enterica serovar Choleraesuis in recent years has become an important public health issue in Taiwan. The resistant strains that cause human infections are considered to be from pigs. In this study, we characterized 157 swine and 42 human Salmonella serovar Choleraesuis isolates by pulsed-field gel electrophoresis (PFGE) and drug susceptibility testing to investigate the epidemiologic relationship among the isolates. By PFGE analyses, two major clusters (clusters GA and GB) were identified. Isolates in cluster GA were of both human and swine origins, while those in cluster GB were from pigs only. Among the various genotypes identified, genotype gt-1a was the most prevalent, which was found in 71% (30 of 42) and 48% (76 of 157) of human and swine isolates, respectively. The susceptibility tests for the 106 gt-1a isolates identified 44 susceptibility profiles and showed that 73% of human isolates and 34% of swine isolates were resistant to three fluoroquinolones (ciprofloxacin, enrofloxacin, and norfloxacin). Our findings indicate that a clonal group of Salmonella serovar Choleraesuis may have been circulating in human and swine populations in Taiwan for years and that the fluoroquinolone-resistant Salmonella serovar Choleraesuis strains most likely evolved from a gt-1a clone that emerged in 2000 and that then caused widespread infections in humans and pigs. Nevertheless, it is still debatable whether those Salmonella infections in humans are caused by isolates derived from pigs, on the basis of the higher fluoroquinolone and other antimicrobial resistance percentages in human isolates than in pig isolates.     

Interleukin-3, -5, and granulocyte macrophage colony-stimulating factor induce adhesion and chemotaxis of human eosinophils via p38 mitogen-activated protein kinase and nuclear factor kappaB

Hematopoietic cytokines such as interleukin (IL)-3, IL-5, and granulocyte macrophage colony-stimulating factor (GM-CSF) play a fundamental role in eosinophil functions in allergic asthma. The intracellular signal transduction mechanisms of these cytokines regulating the activation of eosinophils have been potential therapeutic targets. We investigated the roles of p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-kappaB) in IL-3, IL-5, and GM-CSF-induced adhesion, morphological changes, and subsequence transmigration of human eosinophils. IL-3, IL-5, and GM-CSF could augment the phosphorylation of p38 MAPK and nucleus translocation of NF-kappaB in eosinophils. cDNA expression arrays demonstrated that the gene expression levels of several adhesion molecules including intercellular adhesion molecule-1 (ICAM-1), alpha6, beta2 integrin (CD18), and CD44 were upregulated by these cytokines. Results from functional assays showed that adhesion of eosinophils onto airway epithelial cells was enhanced after IL-3 and IL-5 but not GM-CSF stimulation. These cytokines could markedly induce shape change and augment the transmigration of eosinophils. Moreover, administration of either p38 MAPK inhibitor, SB 203580, or proteasome inhibitor, N-cbz-Leu-Leu-leucinal (MG-132), could inhibit the cytokine-induced adhesion, shape change, and transmigration of eosinophils. Together, our findings suggest that IL-3, IL-5, and GM-CSF regulated the adhesion and chemotaxis of human eosinophils through shared signaling pathways involving both p38 MAPK and NF-kappaB. Our results therefore shed light on the further development of more effective agents for allergic and inflammatory diseases.     

Cognitive and behavioural correlates of non‐adherence to HIV anti‐retroviral therapy: Theoretical and practical insight for clinical psychology and health psychology

This cross‐sectional study identified variables associated with protease inhibitor (PI) non‐adherence in 179 patients taking anti‐retroviral therapy. Univariate analyses identified 11 variables associated with PI non‐adherence. Multiple logistic regression modelling identified three predictors of PI non‐adherence: low adherence self‐efficacy and seriousness of non‐adherence and HIV (p < .001), perceived absence of HIV associated illness (p < .01), and use of more than one type of recreational drug (p = .001). The model correctly classified 83.9% of the sample, offers psychologists insight into psychological barriers to treatment adherence to guide interventions for improving adherence, and supports a modified version of the reformulated health belief model.     

DQB1-0602 (DQw1) is not present in most nonDR2 Caucasian narcoleptics.

Human narcolepsy is a genetically determined disorder of sleep strongly associated with the human leucocyte antigens (HLA) DR2 and DQw1. In black narcoleptic patients, susceptibility for narcolepsy is more closely related to a specific gene subtype of DQw1, DQB1-0602, than to DR2. About 30% of black narcoleptic patients are nonDR2, but all carry the HLA DQB1-0602 gene. In the present study, we have tested caucasian nonDR2 cataplectic patients (6 sporadic cases and 7 familial cases from 3 multiplex families) for the presence of the HLA DQB1-0602 and DQA1-0102 (DQw1) using a specific polymerase chain reaction (PCR)-oligotyping technique. None of the patients was DQB1-0602 or DQA1-0102 positive, thus proving that, in caucasians, DQB1-0602 and DQA1-0102 (DQw1) are not prerequisites for the diagnosis of narcolepsy. Further studies with more patients are warranted to exclude the possibility that a few caucasian patients carry rare haplotypes with DQB1-0602 independently of DR2.     

Changing seroepidemiology of hepatitis B, C, and D virus infections in high-risk populations

Needle-sharing and sexual contact are important transmission routes of hepatitis B, C, and D virus (HBV, HCV, HDV) infection. This study aimed to investigate the current status of these viral infections among high-risk populations including prostitutes and intravenous (i.v.) drug users, compared with the prevalence rate reported previously to examine the changing seroepidemiology. Of the 916 female prostitutes, 79 (9%) were positive for antibody to HCV (anti-HCV), 111 (12%) were positive for HBV surface antigen (HBsAg), and 5 (5%) had antibody to HDV (anti-HDV). The prevalence rate was significantly lower compared to that in 1989-1991 (12%, P = 0.037) for HCV infection, and to that in 1988 (59%) and 1996 (40%) (P < 0.0001) for HDV infection. Of the 494 i.v. drug users, 87 (18%) patients were HBsAg carriers and 12 (14%) were anti-HDV-positive. The prevalence rate of HDV infection was significantly lower than that reported in 1985 (79%, P < 0.0001). Among the 443 tested i.v. drug users, 182 (41%) were anti-HCV-positive, significantly lower than that in 1985 (53%, P = 0.026). Of the 263 male prostitutes, 11 (4%) were anti-HCV-positive, 45 (17%) were HBsAg-positive, and 7 (16%) were anti-HDV-positive. Of the 129 illegal immigrant prostitutes, 7 (5%) were anti-HCV-positive, 15 (12%) were HBsAg-positive and none were positive for anti-HDV. In conclusion, the findings indicate a declining prevalence of HCV and HDV infections among drug users and prostitutes over the past 16 years. Male prostitutes and immigrant prostitutes are new "high-risk" populations and may become a reservoir for disease transmission.