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941.
A prospective blinded study was performed on 191 high-risk patients with pregnancies ranging from 25 to 42 weeks gestation to investigate the value of a single Doppler analysis of the umbilical artery blood flow waveform (systolic-to-diastolic ratio, S/D) for predicting poor perinatal outcome. This was defined as the presence of heavy meconium, delivery of a growth-retarded infant, an umbilical cord arterial pH less than 7.2, or a 5-minute Apgar score less than 7. The interval between Doppler examination and delivery ranged from 12 hours to 15 weeks. No clinical data were available to the examiner performing the Doppler study. Moreover, the Doppler measurements were unknown to the attending physicians. The sensitivity, specificity, and positive and negative predictive values of the Doppler study in predicting outcome were 30.4%, 92.9%, 36.8%, and 92.6%, respectively, with an adverse outcome prevalence of 12%. These results indicate that a single random S/D ratio from the umbilical artery is not an adequate screening test for the risk of perinatal complications.  相似文献   
942.
Conditions that affect the dentition and the materials utilized to treat these conditions are often unfamiliar to the physician. Dental caries and missing teeth are processes routinely treated in dental practice. Recent improvements in dental materials and techniques permit the dentist to restore the dentition to allow for corrected form, function, esthetics, and patient comfort. This paper describes some of the common conditions that affect the dentition, and the modalities routinely used to treat them.  相似文献   
943.
944.
Neisseria meningitidis group B (MenB) strains isolated from 1976 to 1987 in Finland in 339 patients with invasive infection were sero/subtyped by whole cell enzyme immunoassay using monoclonal antibodies to class 1 and 2/3 outer membrane proteins. 66.7% of the strains could be serotyped (class 2/3) and 70.2% subtyped (class 1). No single phenotype was clearly predominant. The most common serotypes were 4 (18.6%) and 14 (17.4%) and the most common subtypes P1.16 (20.1%) and P1.2 (12.1%). The Norwegian phenotype B:15:P1.16 was seen only rarely (a total of 18 strains). Strains from Northern Finland did not differ from those from Southern Finland: no single phenotype caused the slight increase seen in the incidence of MenB infections in the end of 1970s in the North.  相似文献   
945.
946.
Currently available approaches for the design of occupational case-control studies are reviewed. An accompanying paper reviews methods of analysis. We commence by drawing a distinction between cohort-based and registry-based studies. Methods for selecting cases and controls are then reviewed, including cumulative incidence and incidence density sampling, matching, sources of controls, and issues in control selection. Finally, the advantages and disadvantages of the case-control approach are summarized.  相似文献   
947.
Biopharmaceutic comparison is achieved between commercialized capsules of vinburnine and drops dosage form intended for geriatric pharmacotherapy. Drug bioavailability of vinburnine seems saved, if not significantly increased by the new formulation, in spite of the very important, and well known interindividual variations of vincamine drug products. Only the absorption rate seems statistically increased by drops.  相似文献   
948.
Tartrate-resistant acid phosphatase activity (TRAPase) is widely used as a cytochemical marker to distinguish osteoclasts from macrophages and other related cell types. The degree of tartrate resistance, however, may depend on which reaction methods, tissues, or species are used. To investigate this further, we have measured the amount of cytochemical reaction product by microdensitometry. We compared osteoclast acid phosphatase (APase) activity in fresh frozen sections of neonatal rat calvaria using two different reaction methods; one is commonly employed for qualitative histochemistry and includes alpha naphthyl phosphate as substrate, simultaneous coupling to the chromagen Fast Garnet, and a 30-minute reaction time (method A). The other may be used to measure enzyme reaction rates in cells in situ and employs conditions suitable for initial velocity kinetics, namely naphthol-ASBI phosphate as substrate, post coupling to Fast Garnet, and a 2-minute reaction time. Although enzyme reaction rates differed greatly between the two methods, significant inhibition of APase activity by tartrate was observed in calvarial osteoclasts (69% and 59% with methods A and B, respectively), osteoblasts, and spleen macrophages. Using method B, mouse calvarial osteoclasts had similar APase activity to that seen in the rat. Tartrate produced little inhibition in these mouse cells, in contrast to the observations made with rat tissue, but murine spleen macrophages were significantly tartrate sensitive (40% inhibition with tartrate). On this basis, conclusions regarding the cell specificity of TRAPase should be treated cautiously.  相似文献   
949.
950.
Steady flattening of the tumor, increasing reflectivity and decreasing vascularity are echographic signs of successful irradiation treatment. The specific example of an irradiated choroidal melanoma shows that the absence of echographic changes by no means excludes tumor destruction. Because of a dense vitreous body hemorrhage, the melanoma could only be evaluated echographically. Since the echogram lacked evidence of regression, the tumor was locally resected 5 months later. Histology, however, revealed an amorphous mass of dead tissue pervaded by intact vessels. Apparently a successfully irradiated melanoma may generate an echo typical of vital melanoma tissue. The authors therefore draw the conclusion that only a steady tumor growth, as substantiated by an echogram, may be considered an unambiguous sign of tumor vitality.  相似文献   
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