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51.
    
We analyzed the first 5 years of surveillance data from the Established Population for the Epidemiologic Studies of the Elderly (EPESE) in the Piedmont of North Carolina (n = 4162) to estimate the effect of a global self-rating of health on survival. Covariates used in Cox proportional hazard models included sociodemographic factors, chronic medical conditions, activities of daily living, use of health services, health risk behaviors, cognitive function, affective mood, and negative life events. Adjusted risk of mortality associated with poor (compared to excellent) self-ratings of health was significantly elevated among urban men only. Confounders of the association between survival and overall health assessment varied widely by subgroup. Pooled estimates from heterogeneous populations may mask significant subgroup differences both in the pattern of variables that mediate crude risk and also in the magnitude of residual risk of global self-ratings of health.  相似文献   
52.
    
Solitary fibrous tumors are rare neoplasms, most commonly involving the pleura, recently described in various other locations. We report a solitary fibrous tumor of the right adrenal gland in a 42-year-old woman, discovered incidentally during abdominopelvic ultrasonographic examination. Pathologic and immunohistologic features of the tumor were identical to those of other solitary fibrous tumors. Three-quarters of this unencapsulated infiltrating tumoral mass presented foci of hemorrhage and were made of small, round, epithelioid-like cells that expressed the CD34 antigen more weakly than do the typical spindle cells usually observed in solitary fibrous tumors. Despite hemorrhage and poor limitation, the tumor behaved in a innocuous manner; the mass remaining unchanged for more than 5 years before the patient agreed to surgical intervention, which was recommended because of a sudden enlargement of the mass.  相似文献   
53.
    
To more fully define the nature of the antibody response to melanocytes which is associated with vitiligo, a Western immunoblot assay was used to test the sera of 28 patients with vitiligo (21 with active non-segmental, and 7 with stable segmental diseases) and 26 normal individuals for antibodies to antigens in detergent extracts of melanocyte membrane fractions. Antibodies to melanocytes were found in 26 (93%) of the patients with vitiligo, and in 16 (62%) of the control individuals. Patients with vitiligo and control individuals both had antibodies to an 80 approximately 83 kD antigen. The patient with vitiligo, in addition, had antibody responses to antigens with MWs of 45, 65, and 110 kD. Antibodies to these antigens were present in 46, 25, and 31% of vitiligo patients, but in only 19%. 0%, amd 0%, respectively, of the normal individuals. The heterogeneity of the antibody responses to melanocytes in vitiligo was further confirmed by the presence of antibodies to at least 3 distinct antigens in one-third of vitiligo patients but in none of the normal individuals. There was no difference in antibody response between patients with generalized and segmental vitiligo, suggesting that the pathogenesis of diseases was similar in both cases.  相似文献   
54.
    
Intrahippocampal injection(ihci) of guanidinosuccinic acid (GSA) to rats, induced typical generarized clonic seizures and epileptiform discharges in electrohippocampogram (EHG) and electrocorticogram (ECoG), degenerative changes of neuronal cells in the injected side hippocampus. The pyramidal cells in CA1 area were found to be more vulnerable to GSA than the granular cells. Phenobarbital and phenytoin are typical antiepiletics, but in no case did they successfully protect against GSA induced convulsions, epileptiform discharges in the EHG and ECoG and neurolysis. Ketamine, a selective noncompetitive NMDA receptor antagonist, was shown to protect against not only seizures, but also neuronal cell damage induced by GSA. All these results indicate that GSA very like the endogenous excitatory amino acid, glutamic acid, it also has such effects mentioned above. Therefore, the NMDA receptor may mediate both effects of GSA.  相似文献   
55.
    
A sulfate-reducing bacterium using trinitrotoluene (TNT) as the sole nitrogen source was isolated with pyruvate and sulfate as the energy sources. The organism was able to reduce TNT to triaminotoluene (TAT) in growing cultures and cell suspensions and to further transform TAT to still unknown products. Pyruvate, H2, or carbon monoxide served as the electron donors for the reduction of TNT. The limiting step in TNT conversion to TAT was the reduction of 2,4-diamino-6-nitrotoluene (2,4-DANT) to triaminotoluene. The reduction proceeded via 2,4-diamino-6-hydroxylaminotoluene (DAHAT) as an intermediate. The intermediary formation of DAHAT was only observed in the presence of carbon monoxide or hydroxylamine, respectively. The reduction of DAHAT to triaminotoluene was inhibited by both CO and NH2OH. The inhibitors as well as DANT and DAHAT significantly inhibited sulfide formation from sulfite. The data were taken as evidence for the involvement of dissimilatory sulfite reductase in the reduction of DANT and/or DAHAT to triaminotoluene. Hydrogenase purified from Clostridium pasteurianum and carbon monoxide dehydrogenase partially purified from Clostridium thermoaceticum also catalyzed the reduction of DANT in the presence of methyl viologen or ferredoxin, however, as the main reduction product DAHAT rather than triaminotoluene was formed. The findings could explain the function of CO as an electron donor for the DANT reduction (to DAHAT) and the concomitant inhibitory effect of CO on triaminotoluene formation (from DAHAT) by the inhibition of sulfite reductase.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
56.
    
To determine whether a 3-week hepatitis B (HB) vaccination could achieve protective immunity, 89 healthy non-immunized young adults received three doses of 20 micrograms each of HBs antigen (GenHevac B, Pasteur) and were randomly assigned to schedule A (n = 44): two doses at day 0, one dose at day 21; or schedule B (n = 45): one dose at days 0, 10 and 21. Seroprotection rates (anti-HBs > or = 10 mIU ml-1) for groups A and B respectively were: 23 and 40% at day 21; and 77 and 91% at day 82 (not significant). Anti-HBs geometric mean titres were higher in group B than in group A (p < 0.05) at days 21 (6.4 versus 3.8) and 82 (77.6 versus 33.5). One year after primary vaccination, the seroprotection rate remained as high as 90% in the vaccinees of group B; after boosting all vaccinees had protective levels of anti-HBs antibodies. Thus 3-week HB vaccination with GenHevac B allowed early and durable protective immunity.  相似文献   
57.
    
The hypothesis that 'rare' variable number tandem repeat (VNTR) alleles of the Harvey ras (Ha-ras) locus are an inherited predisposing factor in myeloid malignancies has been evaluated. We describe an application of the polymerase chain reaction (PCR) which amplifies the VNTR region at the Ha-ras locus and offers a number of advantages over conventional Southern analysis. Ha-ras VNTR genotypes were assigned to 57 normal subjects, 46 patients with acute myeloid leukaemia (AML), 26 with myelodysplastic syndrome (MDS) and 49 with chronic granulocytic leukaemia (CGL). By comparison with previous reports we found significantly higher frequencies of rare alleles (20.2%) in our normal subjects of whom more than 35% had at least one 'rare' allele. The frequencies of rare alleles in the patient groups was not significantly different from the normal group (chi 2 = 0.54, p = 0.91). In studies of constitutional and leukaemic DNA from patients with AML, we found that allelic loss at the Ha-ras locus was not a common phenomenon. The improved resolution achievable with PCR compared with Southern analysis was demonstrated by the inability of Southern analysis to resolve six out of 34 PCR heterozygotes. We therefore suggest that previous studies showing linkage between rare Ha-ras alleles and susceptibility to malignancy should be reevaluated using our sensitive PCR technique.  相似文献   
58.
    
We studied the features and frequency of sensory neuropathy among 79 HIV-1-infected individuals participating in a multicenter clinical trial of zalcitabine (2'3'-dideoxycytidine, or ddC) antiretroviral therapy. The trial compared zalcitabine monotherapy (2.25 mg/day) versus combination therapy (2.25 mg/day ddC) with zidovudine (ZDV, formerly AZT) versus monotherapy with ZDV alone. Neuropathy developed in 34% of ddC recipients but in only 4% of comparable patients treated with ZDV alone--a 7.9-fold increase in the attack rate of neuropathy. Using risk factor analysis, we found that diabetes mellitus was significantly associated with the development of toxic neuropathy (p = 0.02), and weight loss may contribute to its appearance. Like HIV-associated sensory neuropathy, ddC-related toxic neuropathy is a predominantly sensory, length-dependent, symmetric, painful neuropathy. Dose reduction lessened the severity of symptoms, although objective signs of neuropathy persisted. Patients with subclinical neuropathies or significant neuropathy risks such as diabetes may be poor candidates for ddC therapy.  相似文献   
59.
    
The primary purpose of this investigation was to compare tissue fixation security by simple sutures versus mattress sutures in transosseous rotator cuff repair. These two repair techniques were each performed in 17 human cadaver shoulders, with two bone tunnels being used for the repair by two simple sutures and two other bone tunnels being used for the repair by one mattress suture. The repairs were loaded to failure in a servohydraulic materials test system. Rotator cuff repair by simple sutures was found to be significantly stronger than repair by mattress sutures (P = .0007). The average ultimate load to failure for the simple suture construct (189.62 N) was 39.72% greater than that for the mattress suture construct (135.71 N). Most of the failures occurred by suture breakage at the knot. Load-sharing by multiple suture tails and multiple knots in the simple suture configuration likely contributed to its superior strength characteristics compared with the mattress suture configuration.  相似文献   
60.
    
In the vertebrate retina, a number of proteins involved in signal transduction are known to be N-terminal acylated with the unusual 14 carbon fatty acids 14:1n-9 and 14:2n-6. We have explored possible pathways for producing these fatty acids in the frog retina by incubation in vitro with candidate precursor fatty acids bearing radiolabels, including [3H]14:0, [3H]18:1n-9, [3H]18:2n-6, and [3H]18:3n-3. Rod outer segments were prepared from the radiolabeled retinas for analysis of protein-linked fatty acids, and total lipids were extracted from the remaining retinal pellet. Following saponification of extracted lipids, fatty acid phenacyl esters were prepared and analyzed by high pressure liquid chromatography (HPLC) with detection by continuous scintillation counting. Transducin, whose alpha-subunit (Gt alpha) is known to bear N-terminal acyl chains, was extracted from the rod outer segments and subjected to SDS-polyacrylamide gel electrophoresis and fluorography to detect radiolabeled proteins. Gt alpha was also subjected to methanolysis, and the resulting fatty acyl methyl esters were analyzed by HPLC. The identities of HPLC peaks coinciding with unsaturated species of both phenacyl esters and methyl esters were confirmed by reanalyzing them after catalytic hydrogenation. The results showed that 14:1n-9 can be derived in the retina from 18:1n-9 and 14:2n-6 from 18:2n-6, most likely by two rounds of beta-oxidation, but that neither is produced in detectable amounts from 14:0. Retroconversion of unsaturated 18 carbon fatty acids to the corresponding 14 carbon species showed specificity, in that 18:3n-3 was not converted to 14 carbon fatty acids in detectable amounts. Myristic acid (14:0), 14:1n-9, and 14:2n-6 were all incorporated into Gt alpha. A much less efficient incorporation of 18:1n-9 into Gt alpha was also observed, but no radiolabeling of Gt alpha was observed in retinas incubated with 18:3n-3. Thus, retroconversion by limited beta-oxidation of longer chain unsaturated fatty acids appears to be the most likely metabolic source of the unusual fatty acids found on the N termini of signal transducing proteins in the retina.  相似文献   
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