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91.
Poliovirus RNA polymerase requires a host factor to initiate RNA synthesis in vitro. The host factor was previously purified to near homogeneity from HeLa cells but was not assigned an enzymatic activity. This report describes the purification of a terminal uridylyltransferase that can act as host factor. By all criteria examined it is identical to the factor purified previously. It has the same molecular weight (68,000), chromatographic properties, and cellular localization. We present evidence that terminal uridylyltransferase can add uridine residues to the 3' poly(A) end of virion RNA and that these anneal back to the poly(A) and form a hairpin primer for polymerase.  相似文献   
92.
OBJECTIVE: To ascertain whether tendon samples harvested from patients with calcific insertional Achilles tendinopathy showed features of failed healing response, and whether abnormal quantities of type II collagen had been produced in that area by these tenocytes. DESIGN: Comparative laboratory study. DESIGN: University teaching hospitals. PATIENTS: Tendon samples were harvested from eight otherwise healthy male individuals (average age 47.5+/-8.4 years, range 38 to 60) who were operated for calcific insertional Achilles tendinopathy and from nine male patients who died of cardiovascular events (mean age 63.1+/-10.9 years) while in hospital. INTERVENTIONS: Open surgery for calcific insertional Achilles tendinopathy. MAIN OUTCOME MEASURE: Semi-quantitative histochemical, immunohistochemical, and immunocytochemical methods to ascertain whether tendinopathic tendons were morphologically different from control tendons, and whether abnormal types of collagen were produced. RESULTS: Tenocytes from tendons from patients with calcific insertional Achilles tendinopathy exhibit chondral metaplasia, and produce abnormally high quantities of collagen type II and III. CONCLUSIONS: The altered production of collagen may be one reason for the histopathological alterations described in the present study. Areas of calcific insertional Achilles tendinopathy have been subjected to abnormal loads. These tendons may be less resistant to tensile forces. Further studies should investigate why some tendons undergo these changes.  相似文献   
93.
Twenty-six patients with relapsed or drug-resistant cancer were treated with a combination of oral etoposide (300 mg day-1 for 3 days) and high-dose oral tamoxifen as a potential modulator of drug resistance (480 or 720 mg day-1 for 6 days beginning 3 days before etoposide). One patient with relapsed high-grade lymphoma and one with adenocarcinoma of unknown primary site has a partial response. Toxicity consisting of nausea, vomiting and subjective dizziness, unsteadiness of gait and malaise occurred during tamoxifen treatment. Serum levels of tamoxifen averaged 3-3.5 microM on day 4 of all courses of treatment at both 480 and 720 mg day-1. N-desmethyltamoxifen levels were lower than tamoxifen during the first course (2 microM) but increased to equal tamoxifen levels during the second course. Didesmethyltamoxifen levels remained below 1 microM. In vitro, both tamoxifen and the standard modulator of multidrug resistance, verapamil, produced minor enhancement of etoposide cytotoxicity in the MCF-7 wt cell line but produced no enhancement with any other cell line. High, intermittent doses of tamoxifen can be given with acceptable toxicity and produce serum levels that have been shown to modulate drug resistance in vitro. In vitro, however, such levels have no significant effect on etoposide cytotoxicity towards a range of wild-type and MDR cell lines.  相似文献   
94.
A 32-year-old woman was referred complaining of abdominal pain and bleeding at 18 weeks' gestation. The striking finding on ultrasound examination was of symmetrically enlarged echogenic fetal lungs. In addition, mediastinal compression, increased echogenicity of the kidneys and bowel, an enlarged liver of decreased echogenicity, and hydrops fetalis, as evidenced by ascites and skin edema, were all present. The differential diagnosis included upper respiratory tract obstruction and cystic kidney disease. The presence of fetal hydrops together with the other findings suggested a poor outcome, and on these grounds therapeutic abortion was recommended and performed. Subsequent postmortem findings explained all the ultrasound abnormalities on the basis of extensive fetal candida infection. The presence of a retained intrauterine contraceptive device was considered to be the likely cause and the implications of this, together with the ultrasound abnormalities and differential diagnoses, are discussed.  相似文献   
95.
A recent study demonstrated that the incidence of new arrhythmias occurring during central venous catheter insertion or exchange was 41% atrial and 25% ventricular arrhythmias (12% couplets or greater). Over-insertion of the guidewire, causing direct stimulation to the right side of the heart, has been postulated to be the causative factor. A new technique that allows the operator to control the length of guidewire inserted was developed. With this technique on a population of hospitalized patients, similar to those in the previous study, the incidence of atrial arrhythmias decreased to 32% and the incidence of ventricular arrhythmias to 6% (single premature ventricular contractions only). Although this new technique has limitations, there was a dramatic improvement in the incidence of cardiac arrhythmias. These results indicate a need for modifications in the available equipment to avoid the infrequent but life-threatening complication of malignant arrhythmia.  相似文献   
96.
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98.
The sensitivity and regional specificity of intraoperative electroencephalographic (EEG) monitoring in cerebral ischemia was evaluated in a new experimental model of temporary focal cerebral ischemia in rabbits. EEG potentials were recorded directly from the cortical surface using a bipolar disc electrode grid and were analyzed by computer. Groups of 5 animals each underwent temporary occlusion of the left middle cerebral arterial trunk for 5, 10, 20, 30, 45, or 60 minutes. EEG data were recorded from the cortex proximal (temporal site) and distal (parasagittal site) to the middle cerebral arterial trunk during occlusion and 2 hours of reperfusion. EEG suppression was detected immediately after occlusion at the temporal site by analysis of power spectra in 29 of 30 rabbits (mean power, 32% of base line), by compressed spectral array (CSA) edge analysis in 23, and by analysis of the conventional EEG wave form in 24. Within 5 minutes after the start of occlusion, all 30 rabbits showed EEG power suppression and 26 showed decrease in the CSA edge frequency or in the routine EEG wave form. By the end of the occlusion period, EEG power at the temporal site had decreased to 20.5% of base line. At the parasagittal site, a lesser degree of EEG suppression was detected; 20 rabbits had an initial loss of EEG power (mean, 85.7% of base line), 13 had decrease in the CSA edge, and 7 had suppression of the EEG wave form. By the end of the occlusion period, spectral power at the parasagittal site had decreased in 25 of 30 rabbits to a mean of 86.9% of base line.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
99.
This review of journal articles and book chapters discusses the health beliefs characteristic of Polynesia and reveals several themes. These are: commonality in health conceptualisations across the cultures of the region which differ from the conceptualisations of biomedicine; the role of the relational self, traditional living and communalism in understanding health; the place of spirituality and religion in health and illness causation; and pluralism and pragmatism in health-seeking behaviour. Suggestions are made as to how awareness of key ideas might contribute to effective planning of health promotion and intervention activities.  相似文献   
100.
BACKGROUND: Protein-energy malnutrition occurs commonly in patients receiving hemodialysis (HD). Although serum albumin (sAlb) is recommended to monitor nutrition status in patients receiving HD, many processes unrelated to nutrition status can affect albumin concentrations. METHODS: We previously showed normalized protein catabolic rate (nPCR) to be superior to sAlb to reflect improvement in nutrition status in pediatric patients receiving maintenance HD after treatment with intradialytic parenteral nutrition for severe protein-energy malnutrition. We now compare nPCR and sAlb as nutrition status markers for pediatric patients on HD irrespective of current nutrition status. RESULTS: Forty-four patients comprising 840 months of HD provision were assessed. nPCR was higher for younger patients. Mean nPCR values were significantly lower for adolescent patients with persistent weight loss of at least 2% for at least 3 consecutive months versus patients without persistent weight loss (1.03 +/- 0.29 g/kg/d vs. 1.15 +/- 0.27 g/kg/d, P < .002), and the odds for developing persistent weight loss were four times greater for adolescent patients with nPCR less than 1 g/kg/d. No association between nPCR and weight loss was observed for younger patients. Mean sAlb levels were greater than 4 g/dL for all patient age groups and did not demonstrate a clinically significant difference between patients with or without weight loss. CONCLUSION: We suggest that nPCR may be useful for monthly nutrition status in adolescent patients receiving maintenance HD and that adolescents with nPCR less than 1 g/kg/d may be at increased risk for subsequent weight loss.  相似文献   
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