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101.
Several recent reports have described cases of acute nonlymphocytic leukemia with a unique chromosome translocation, t(6;9)(p23;q34). We have studied three additional patients who have acute nonlymphocytic leukemia and t(6;9)(p23;q34). Our findings provide additional support for the suggestion that this translocation is yet another distinct cytogenetic abnormality associated with myeloproliferative disorders.  相似文献   
102.
Stress, coping, and hepatitis B antibody status   总被引:4,自引:0,他引:4  
OBJECTIVE: The present study investigated the association between exposure to stressful life events, coping style, and antibody status after hepatitis B vaccination. METHODS: Two hundred sixty medical school undergraduates, who had received the three-dose hepatitis B vaccine before recruitment to this study, completed questionnaires measuring exposure to stressful life events during the past year, customary coping strategies, and health behaviors. Antibodies against hepatitis B surface antigen were determined; levels <100 mIU/ml were deemed inadequate. RESULTS: Two participant cohorts were identified: those vaccinated within the last year and those vaccinated earlier. In the early vaccination cohort, participants with greater-than-average stress exposures had a more than two-fold increased risk of having an inadequate antibody titer. Coping by accepting the reality of stressful situations proved protective, whereas coping by substance use increased the risk of having an inadequate antibody count in this cohort. These associations remained significant after adjustment for possible mediators. Furthermore, the effects of stress and coping were largely independent of one another. Neither stress nor coping was significantly associated with antibody status in the recently vaccinated cohort. CONCLUSIONS: The present study confirms that the immune system is sensitive to variations in psychological factors. Stressful life events and coping strategy seem to have a continuing impact on hepatitis B antibody status.  相似文献   
103.
Antiserum to polyacrylamide gel-purified simian virus 40 T antigen.   总被引:12,自引:0,他引:12  
Antisera used previously to assay SV40 T antigen have been produced in tumor-bearing hamsters. This report describes the production and characterization of antiserum produced by injection of rabbits with denatured large-T antigen (Ag) purified by immunoprecipitation and electrophoresis. The resulting antiserum reacts with native large-T Ag as determined by indirect immunofluorescence, complement fixation, and indirect immunoprecipitation assays and binds to species such as “small-T Ag” and previously described proteolytic fragments of large-T Ag.  相似文献   
104.
105.
The aims of this study were to determine whether the administration of cortisol has a significant effect on mood in patients with depression and whether the effects of cortisol on changes in plasma hormone concentrations are like those of synthetic corticosteroids. Twelve patients had major depression and one each had dysthymic disorder and a depressive adjustment disorder. Five were male and nine were female. All were in-patients. Eight normal subjects, two females and six males, were used as controls. Basal beta-endorphin concentrations were 2- to 3-fold higher in depressed patients than in control subjects, but there were no significant differences between the patient and control groups in the basal (pre-infusion) plasma concentrations of ACTH, cortisol, growth hormone or prolactin. Cortisol, but not saline infusion resulted in a significant improvement in self rated mood. Surprisingly, cortisol infusion at first increased plasma beta-endorphin concentrations. At later times after cortisol infusion, plasma beta-endorphin concentrations decreased as did the plasma concentrations of ACTH and growth hormone; prolactin levels were increased. These results show (i) that cortisol infusion raises mood significantly in major depression, (ii) that plasma beta-endorphin concentration is a potential marker of major depression (iii) that rather than blunting of corticosteroid effects, responses to cortisol may even be enhanced in depressive illness. The unexpected, initial increase in beta-endorphin stimulated by cortisol, suggests that the action of cortisol is not simply one of negative feedback inhibition, but may involve mineralocorticoid, as well as glucocorticoid receptors.  相似文献   
106.
Douglas  Carroll  Michael G.  Harris  Gwen  Cross 《Psychophysiology》1991,28(4):438-446
Cardiac output, heart rate, stroke volume, pre-ejection period, total peripheral resistance, systolic and diastolic blood pressure, and oxygen consumption were monitored or derived in young men with mildly elevated casual blood pressures and unambiguously normotensive control subjects before, during, and after exposure to a mental arithmetic stress. Measurements were also taken while subjects underwent graded dynamic exercise. This permitted cardiac output-oxygen consumption regression equations to be calculated and, as a consequence, cardiac output during mental stress to be represented as additional cardiac output. Systolic and diastolic blood pressure were higher during all phases of the study in the mildly elevated blood pressure group. An overall groups effect during the mental stress phase of the experiment was observed for cardiac output and pre-ejection period, and the effect for stroke volume was close to significance. Significant Groups X Periods interactions were found for cardiac output and additional cardiac output, and the heart rate effect was nearly significant. Post-hoc comparisons here indicated that, in the main, group differences in these cardiac variables were more evident during the mental arithmetic stress than during the pre- and post-task baseline periods. Total peripheral resistance did not differ reliably between groups and the cardiac effects were specific to the mental stress phase of the study.  相似文献   
107.
Morphological studies have shown that macrophages and microglia undergo apoptosis in the central nervous system (CNS) in acute experimental autoimmune encephalomyelitis (EAE) in the Lewis rat. To assess the relative levels of macrophage and microglial apoptosis, and the molecular mechanisms involved in this process, we used three-colour flow cytometry to identify CD45lowCD11b/c+ microglial cells and CD45highCD11b/c+ macrophages in the inflammatory cells isolated from the spinal cords of Lewis rats 13 days after immunization with myelin basic protein (MBP) and complete Freund's adjuvant. Simultaneously, we analyzed the DNA content of these cell populations to assess the proportions of cells undergoing apoptosis and in different stages of the cell cycle or examined their expression of three apoptosis- regulating proteins, i.e. Fas (CD95), Fas ligand (FasL) and Bcl-2. Microglia were highly vulnerable to apoptosis and were over-represented in the apoptotic population. Macrophages were less susceptible to apoptosis than microglia and underwent mitosis more frequently than microglia. The different susceptibilities of microglia and macrophages to apoptosis did not appear to be due to variations in Fas, FasL or Bcl- 2 expression, as the proportions of microglia and macrophages expressing these proteins were similar, and were relatively high. Furthermore, in contrast to T cell apoptosis, apoptosis of microglia/macrophages did not occur more frequently in cells expressing Fas or FasL, or less frequently in cells expressing Bcl-2. These results indicate that the apoptosis of microglia and CNS macrophages in EAE is not mediated through the Fas pathway, and that Bcl-2 expression does not protect them from apoptosis. Expression of FasL by macrophages and microglia may contribute to the pathogenesis and immunoregulation of EAE through interactions with Fas+ oligodendrocytes and Fas+ T cells. The high level of microglial apoptosis in EAE indicates that microglial apoptosis may be an important homeostatic mechanism for controlling the number of microglia in the CNS following microglial activation and proliferation.   相似文献   
108.
Gastroduodenal mucus is present as a water insoluble gel adherent to the mucosal surface and as a viscous mobile solution in the lumen. The protective properties of the mucus against acid (with bicarbonate), pepsin (diffusion barrier) and mechanical damage depend on the quality (structure) and quantity (thickness) of the adherent mucus gel layer. Adherent mucus is a viscoelastic gel which is 95% (v/v) water. It is permeable to ions and smaller molecules (Mr c. 1000), but is impermeable to large proteins (Mr,c. 17,000) including pepsins. However, mucus is solubilized rapidly by pepsin, more slowly (>-1 h) by thiol agents, and is unchanged following exposure to bile, acid and ethanol (<40%). Glycoprotein macromolecules (Mr≥2×106) are the structural components of the mucus gel and have a polymeric, structure of glycoprotein subunits (Mrc. 5×105, for gastric mucus) joined by disulphide bridges between their protein cores. This glycoprotein polymerization, which is essential for gel formation and hence function, is the site of action of proteolytic enzymes and thiol agents. The glycoprotein polymeric structure is deficient in antral mucus from patients with peptic ulcer disease.In vivo, adherent mucus forms a thin but continuous cover of variable thickness (50–450 μm in man, about two-fold less in rat) over the gastroduodenal mucosa. Pepsin in gastric juice will rapidly dissolve this mucus cover and can be active up to luminal pH values of 5. Mucus erosion by pepsin or by abrasion must be balanced by its secretion. Prostaglandins and carbachol stimulate a rapid increase (within minutes) in mucus thickness of up to two-fold. Soluble luminal mucus can be increased by mucus secretagogues, mucosal damaging agents, or peptic degradation of adherent mucus. Increases in luminal mucus can occur independently of increased gel thickness.  相似文献   
109.
The effect of conditioning stimuli on the F-response was investigated in normal subjects using stimulus pairs with interstimulus intervals of 1 to 400 ms. The "recovery curve" for the F-response was found to be similar to that for the H-reflex but differences were found between male and female subjects. The significance of these findings is discussed.  相似文献   
110.
P Welch  C Grossi  A Carroll  W Dunham  S Royal  E Wilson  W Crist 《Cancer》1986,57(5):1005-1010
A 6-year-old girl with a granulocytic sarcoma (GS) of the left maxillary sinus that followed a uniquely indolent clinical course (3.5 years) and was associated with highly destructive skeletal disease is described. The tumor cells demonstrated an unusual hematogenous "homing" preference for bone and soft tissue sites. Tumor cell characterization with immunologic markers, electron microscopy, cytochemistry, and cytogenetic studies revealed that the tumor cells expressed OKM1 and MMA (Leu-M1), but not HLA-DR, B-, or T-cell markers. The cells were nonspecific esterase- and myeloperoxidase-positive, had ultrastructural features of promyelocytes, and were clonal. The laboratory characterization of the tumor cells in this clinically unusual case of GS illustrates the utility of monoclonal antibodies, applied in conjunction with cytochemistry and ultrastructural analysis, in establishing the specific diagnosis, cell lineage, and maturational stage of this tumor.  相似文献   
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