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Biomedical subjects

A Wolf

Publications and source records attributed to A Wolf.

At least 271 records · Page 15Linked to original sources
PubMed1988

[Detection of Chlamydia trachomatis in routine clinical practice: increased sensitivity of cell culture in comparison with the microimmunofluorescence test].

Recently, direct immunofluorescence staining has been reported as a new tool for detection of Chlamydia trachomatis. This assay is based on monoclonal antibodies directed against a protein present in all serological variations of Chlamydia known to date. In order to evaluate whether immunofluorescence staining could substitute for the time-consuming, expensive tissue culture technique, urethral and cervical swabs of 131 patients treated for sterility were examined for infection with Chlamydia by both methods. The tissue culture technique, based on cultivation of Chlamydia in mammalian cells, was regarded as 100% sensitive and specific. Employing this method, we demonstrated infection with Chlamydia in 20 patients (15.3%). Colonization of both, cervix and urethra was found in 11.5%, whereas solitary colonization of cervix and urethra was found in 2.3 and 1.5% respectively. However, the immunofluorescence assay applied ("Micro-Trak", Syva Company) showed positive results in only 6 out of 20 cases as determined by tissue culture, thus yielding a sensitivity of 30%. Out of 111 patients with negative results in the tissue culture, 108 were detected by immunofluorescence staining, amounting to a specificity of 97.3%. With special regard to the low sensitivity of the direct immunofluorescence assay, our results indicate a superior, yet unequalled role of the tissue culture technique for detection of Chlamydia trachomatis.

Bacteriological Techniques↗
PubMed1988

Lysolecithins as endothelium-dependent vascular smooth muscle relaxants that differ from endothelium-derived relaxing factor (nitric oxide)

The effects of lysolecithin (lysophosphatidylcholine) derived from egg yolk as well as of synthetic lysolecithins with different aliphatic chain lengths on tension development of rabbit aortic strips were investigated. Lysolecithins caused slowly progressing, dose-dependent relaxation that was inhibited by hemoglobin, methylene blue, and nordihydroguiaretic acid. Indomethacin caused no inhibition of relaxation. The degree of relaxation was endothelium-dependent and appeared to be related to the activation of guanylate cyclase [GTP pyrophosphate-lyase (cyclizing), EC 4.6.1.2]. Superoxide dismutase failed to influence relaxation. Lysolecithins with the longest aliphatic chain were the most potent relaxants of aortic strips. The experiments suggest a role of lysolecithins through their weak detergent action on membrane dynamics of endothelial cells, resulting in the production of cyclic GMP and the relaxation of arterial smooth muscle. Lysolecithins differ in several respects from endothelium-derived relaxing factor. Endothelium-derived relaxing factor is an unstable humoral substance released from endothelium and is identical to nitric oxide, itself a labile substance causing vascular relaxation and cyclic GMP accumulation. Lysolecithins may represent a different type of endothelium-dependent muscle relaxant.

Acetylcholine↗
PubMed1988

Infusions of propofol to supplement nitrous oxide-oxygen for the maintenance of anaesthesia. A comparison with halothane.

The peri-operative and postoperative effects of propofol given by infusion were compared with halothane as a supplement to nitrous oxide-oxygen anaesthesia for body surface surgery in patients who breathed spontaneously. Anaesthesia was induced after opioid premedication, with either propofol 2.5 mg/kg or thiopentone 4-5 mg/kg which were followed respectively by an infusion of propofol 12 mg/kg/hour for 10 minutes and at a variable rate thereafter, or by halothane at a mean inspired concentration of 1.2%. Maintenance of anaesthesia required a median rate of infusion of propofol of 149.4 micrograms/kg/minute. The cardiovascular effects during induction and maintenance of anaesthesia were similar in the two groups. The overall incidence of side effects was low but immediate recovery was significantly faster in patients who received propofol.

Adult↗
PubMed1988

Low frontal glucose utilization in chronic schizophrenia: a replication study.

Frontal/posterior ratios of cerebral glucose metabolism as determined by positron emission tomography were significantly lower in 13 chronic schizophrenic patients than in eight normal control subjects, as were absolute metabolic rates in both the frontal and posterior regions. The differences were not accounted for by cerebral atrophy.

Adult↗
PubMed1988

[Treatment of Crohn disease with intravenous immunoglobulin].

In a 14.5 year old girl with Crohn's disease a complete remission was achieved with intravenous immunoglobulins. Earlier treatment with various therapeutical regimens had been unsuccessful. During the next two relapses the same prompt positive response was reproducible, whereas in the third the dose of immunoglobulin had to be doubled.

Adolescent↗
PubMed1988

[Perinatal problems in fetal macrosomy and its relation to maternal Hb A1C].

Although the frequency of macrosomic newborns decreased within the last years due to an intensive centralized care of women with diabetes mellitus, 175 new borns had a birth weight of more than 4,000 grams in 1986 (total number of deliveries 2,339). Within this collective increasing maternal as well as fetal risks and perinatal complications increased rapidly corresponding to the rising birth weight. When clinical parameters were related to maternal levels of HBA1C, which was determined immediately after delivery, a dependency of the height of glycolised hemoglobin was related to several perinatal problems e.g. maternal obesity, gestosis, maternal-fetal disproportion, operative delivery and fetal morbidity. These data stress upon the necessity of a general screening program for the early detection of metabolic dysfunction of carbohydrate.

Birth Weight↗
PubMed1988

[Dynamic contrast medium studies with flash sequences in nuclear magnetic resonance tomography of the breast].

In this study the dynamic contrast behavior after Gd-DTPA of different breast tissues and tumors has been investigated with a series of T1-weighted FLASH-sequences during the first 5 minutes after the application of Gd-DTPA. The results of these dynamic FLASH-measurements have been compared to the results of the SE-sequences 6-10 and 11-15 minutes after Gd-DTPA in 40 patients with 54 different breast tissues. It could be shown that in a number of cases a better differentiation (e.g. DD between carcinomas and proliferative dysplasia) was possible on FLASH-scans early after contrast medium than on the late SE-scans. Only the distinction between non-proliferative and proliferative dysplasia was better on the late SE-scans. Evaluation of the enhancement dynamics may be helpful in some cases as an additional information. Further investigations are necessary to confirm these findings and to assess their value.

Breast↗
PubMed1987

Synthesis of spin-labeled photoaffinity derivatives of NAD+ and their interaction with lactate dehydrogenase.

The synthesis of NAD+ derivatives spin-labeled at either N6 or C8 of the adenine ring is described, in which the carboxamide function of the nicotinamide moiety is replaced by a diazirine ring. Irradiation of these compounds at 350 nm generates a carbene which will react with any functional group in its vicinity including hydrocarbons. Both NAD+ derivatives form tight ternary complexes with lactate dehydrogenase and were covalently incorporated into this enzyme. They may be employed for ESR studies when non-covalent interactions are too weak for motionally restricted species to be observed.

Animals↗
PubMed1987

Effects of amphetamine on local cerebral metabolism in normal and schizophrenic subjects as determined by positron emission tomography.

The effects of d-amphetamine (0.5 mg/kg PO) on regional cerebral glucose utilization were measured with Positron Emission Tomography (PET). Subjects included ten chronic schizophrenics and six controls who received amphetamine, and six chronic schizophrenics and nine controls who received placebo or no treatment. Amphetamine decreased glucose metabolism in all regions studied (frontal, temporal, and striatal) in normal and schizophrenic subjects. The metabolic effects of amphetamine were correlated with plasma level of the drug. Cortical atrophy was associated with a blunted metabolic response.

Adult↗
PubMed1987

Alcohol teratogenicity in the human: a detailed assessment of specificity, critical period, and threshold.

Though the occurrence of alcohol-related birth defects is well documented in the human and in animal models, definition of specificity, critical period, and dose-response threshold with a precision adequate for clinical risk assessment and management has been lacking. Data from a cohort of 359 neonates, from a large prospective observational study in which chronic alcohol problems and maternal drinking were assessed during pregnancy and standardized neonatal examinations were blinded for prenatal information, were analyzed with the use of multivariate techniques, with uniform control for confounding by eight factors. Craniofacial abnormalities were found to be definitively related to prenatal alcohol exposure in a dose-response manner (p less than 0.001); a significant, but less striking, relationship was observed for other anomalies (p less than 0.01). The critical period for alcohol teratogenicity was confirmed to be around the time of conception. Risk for anatomic abnormalities in the offspring was clearly defined among the 5.6% of infants whose mothers drank more than three ounces of absolute alcohol, that is, more than six drinks, per day. Because of a trend toward an increase in craniofacial abnormalities with increasing embryonic alcohol exposure at lower levels, a clear threshold could not be defined. These are not experimental data and the results should not be overinterpreted. Nevertheless, pending further studies with larger samples, the findings suggest that to completely avoid alcohol-related anatomic abnormalities, advice to discontinue drinking or at least to reduce it to a minimal level before conception is clinically appropriate.

Alcohol Drinking↗
PubMed1987

Somatostatin-like immunoreactivity in cerebroventricular fluid of patients with basal midline tumours.

The concentration of somatostatin-like immunoreactivity (SLI) was determined by specific radioimmunoassay in the cerebroventricular fluid of patients with tumours of the basal midline and compared to findings in patients with multiple sclerosis. Mean SLI levels of the two groups were not significantly different. In patients with basal tumours (astrocytoma, craniopharyngioma, etc.) SLI levels varied widely and tended to increase with increased intracranial pressure. Lateral ventricular SLI levels decreased in patients with blockade of foramen Monro and in patients with communicating hydrocephalus or post-radiation encephalopathy. There was no apparent correlation with dysfunction of the hypothalamohypophyseal axis.

Adolescent↗