Catecholaminergic pathways in the brain are activated during stress and are presumably involved in the control of physiological and behavioral changes triggered by stress. When repeatedly stressed, adaptive changes have been observed in catecholaminergic activity in the brain. In the present experiment, it was assessed whether or not chronic exposure to immobilization (IMO) altered the influence of catecholamines on behavior in the holeboard and forced swim test by administering alpha-methyl-p-tyrosine (an inhibitor of catecholamine synthesis). Adult Sprague-Dawley rats were used. Chronic stress amortiguated the inhibitory effect of acute IMO on some but not all behaviors in the two tests. Whereas previous chronic IMO exacerbated the effects of the drug on struggling and immobility in the forced swim test, no change in response to the drug as a consequence of chronic IMO was observed in the holeboard test. The present data suggest that chronic IMO-induced changes in the catecholaminergic control of some behaviors might be related to depression-like states in rats. The actual physiological meaning of these changes and the specific receptors involved remain to be elucidated. 相似文献
Background. A major concern in evaluating dynamic cardiomyoplasty has been whether the synchronous stimulation of latissimus dorsi muscle is essential for benefit or not. We studied 10 patients to determine the efficacy of the systolic augmentation generated by the synchronous electrical stimulation of the latissimus dorsi muscle.
Methods. Left ventricular ejection fraction, end-systolic and end-diastolic volume indexes, and stroke volume index obtained during resting, peak exercise, and recovery periods (“on” values) were compared with those obtained 1 week after cessation of electrical stimulus (“off” values). Double product and estimated total body oxygen consumption at peak exercise were also calculated and compared.
Results. Higher ejection fractions (0.36 ± 0.07 versus 0.33 ± 0.06 at rest, 0.40 ± 0.07 versus 0.33 ± 0.07 peak exercise, and 0.37 ± 0.06 versus 0.31 ± 0.06 at recovery) and lower end-systolic volume indexes with relatively constant end-diastolic volume indexes were observed with the cardiomyostimulator on. Further, exercise response was better with the cardiomyostimulator on. Double product indirectly reflected better myocardial oxygen supply/demand ratio when on at peak exercise (17 ± 2.2 mm Hg × beats/min × 10−3 for on versus 19 ± 2.6 mm Hg × beats/min × 10−3 for off). Estimated total body oxygen consumption was improved at peak exercise when the cardiomyostimulator was functional (12 ± 2.7 mL · kg−1 · min−1 versus 11 ± 2.6 mL · kg−1 · min−1).
Conclusions. Current data suggest a true systolic assist during synchronous contractions of the latissimus dorsi muscle. It is thought, therefore, that synchronous electrical stimulation is essential for maximum benefit and all the beneficial effect of cardiomyoplasty certainly cannot be attributed to simple wrapping itself. 相似文献
A comparative statistical analysis of "synaptic ribbons" evolution over a 24 hour period during two different photoluminous seasons (September, and winter) is carried out. Seventy male rats were used. Statistical analysis involved the Kolmogorov-Smirnov test, variance analysis, the Student t-test and Pearson's correlation test. The results show that "synaptic ribbons" evolve during the circadian phase and through two different seasons, with a clear and marked influence of point-time (p < 0.0001) and season (p < 0.0001). 相似文献
The purpose of this study was to investigate the epidemiologic characteristics of the death by poisoning in Korea. We recoded the Death Certificates Database by injury based on the short version of the International Classification of External Causes of Injuries (ICECI). We evaluated the mortality rate by total injury and poisoning, and analyzed the mortality rate by age, gender, year and month, toxic agent, and intent. Adjusted odds ratios were calculated to evaluate the effects of socioeconomic factors on suicidal poisoning death. The total number of death cases by injury was 346,656. The proportion of death cases by injury decreased from 13.53% of all death cases in 1991 to 11.89% in 2001. However, the mortality rate by poisoning increased rapidly from 1998, and then remained stable. The number of suicidal poisoning deaths has gradually increased, and its mortality rate was 6.41 (per 100,000) in 2001. Major toxic agents were pesticides and herbicides (50.90%) in 2001. Adjusted odds ratios of suicidal poisoning versus other poisonings showed significant differences in education attainment, region, and marital status. In conclusion, the mortality rate by poisoning has increased, and the proportion of suicidal poisoning also has increased compared to that of accidental poisoning. 相似文献
A direct extraction of the antigens of group A beta-hemolytic streptococci from 557 throat swabs was performed by a new microtechnique of the nitrous acid extraction method with the Culturette Brand Ten-Minute Strep ID technique from Marion Scientific, Division of Marion Laboratories, Inc., Kansas City, Mo. This group A latex reagent kit contains the reagents for the micronitrous acid extraction of throat swabs and does not require a centrifugation step in its protocol. There was a 99.3% (553 of 557) total agreement between the direct nitrous acid extraction-latex agglutination method and the standard culture method. The direct extraction method yielded an identification of 95.1% (78 of 82) of the group A streptococci identified by the standard method. Throat swabs used for standard culture may also be extracted with nitrous acid for the detection of group A antigen. A 5-min nitrous acid extraction destroys the viability of bacteria associated with normal throat flora as well as group A streptococci and Mycobacterium tuberculosis. This highly rapid method is simple to perform and requires no costly instrumentation. Accordingly, it would be most applicable in a hospital laboratory as well as in a physician's office. 相似文献
We report a case of ruptured mycotic aneurysm involving innominate artery requiring an urgent surgical treatment. A 62-yr-old woman presented with fever and dyspnea. Previously, she was diagnosed with colon cancer and received right hemicolectomy and one cycle of adjuvant chemotherapy. On echocardiogram, pericardial effusion was noted and emergency pericardiocentesis was performed. CT scan revealed aortic aneurysm involving ascending aorta and innominate artery, and thrombi surrounding those structures. Patch repair of the defect in the ascending aorta and ringed Goretex graft to bypass the innominate and ascending aorta were performed. We believe that this is the first case of ruptured mycotic aneurysm involving innominate artery. 相似文献
Francisella tularensis is a highly infectious gram-negative bacterium with potential for use as a bioweapon. Analysis of the F. tularensis live vaccine strain (LVS) ultrastructure by electron microscopy revealed the presence of long, thin fibers, similar in appearance to type 4 pili. The highly virulent F. tularensis Schu S4 strain was found to contain type 4 pilus genes, and we confirmed that these genes are present and expressed in the LVS. 相似文献
OBJECTIVE: To determine the extent to which daily stress and mood are associated with pain, health-care use, and school activity in adolescents with sickle cell disease (SCD). METHOD: Adolescents with SCD (n = 37; aged 13 to 17 years) completed daily diaries assessing pain, stress, mood, activity, and health-care use for up to 6 months. Multilevel modeling was used to analyze the data. RESULTS: Daily increases in stress and negative mood were associated with increases in same-day pain, health-care use, and reductions in school and social activity. Increases in positive mood were associated with decreases in pain, less health-care use, and more activity participation. Notably, pain was predictive of higher stress and lower positive mood on subsequent days. CONCLUSION: Pain in adolescents with SCD is stressful and may lead to alterations in mood states. Understanding the way in which these variables relate to health-care use and activity may lead to improved pain management approaches. 相似文献
Walls of the two cellular forms (blastoconidia and mycelia) of Candida albicans ATCC 26555 were obtained from cells metabolically labeled (6-h pulse) with 14C-protein hydrolysate and [3H]threonine. Walls were purified by thorough washings with buffered and sodium dodecyl sulfate solutions and digested with Zymolyase 20T. The enzymatic treatment released four major high-molecular-weight mannoproteins (HMWM), with apparent molecular masses of 650, 500, 340, and 200 kilodaltons (HMWM-650, HMWM-500, HMWM-340, and HMWM-200, respectively), from yeast cells, whereas two high-molecular-mass mannoproteins (HMWM-260 and HMWM-180) were solubilized from mycelial cells. Some additional minor low-molecular-weight species were also detected in the enzymatic digests of walls from both types of cell. Single and dual pulse-chase experiments indicated that the HMWM-260 and HMWM-180 species reflect de novo synthesis of new proteins specific for the mycelia and do not represent a topological rearrangement of blastoconidium wall components. Monoclonal antibodies were raised against the HMWM-260 species (quantitatively the predominant component in the mycelial walls), and polyclonal rabbit antibodies were obtained against yeast or mycelial cell walls. Anti-mycelial cell wall polyclonal antibodies were adsorbed to whole killed blastoconidia to remove antibodies against common blastoconidium and mycelial wall antigens. Titration by enzyme-linked immunosorbent assay revealed that the monoclonal antibodies could recognize an epitope of the protein moiety of the HMWM-260 mannoprotein. Immunoblotting and immunofluorescence techniques using these monoclonal and polyclonal antibodies confirmed that the HMWM-260 and HMWM-180 species are specific components of the envelope of the mycelial cell walls. 相似文献