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Biomedical subjects

H Wolf

Publications and source records attributed to H Wolf.

At least 559 records · Page 31Linked to original sources
PubMed1984

New developments in nucleic acid hybridization.

Nucleic acid hybridization is widely used for scientific applications in specialized laboratories. This paper describes hybridization probes that can be prepared with less specialized equipment. A new indirect 'sandwich' hybridization test is described which allows the use of only one universally usable labelled probe for hybridization tests with specificities for various sequences. The use of different labels and hybridization techniques is also discussed and critically compared. For in situ hybridization, the usability of fixed and embedded materials is tested and evaluated.

DNA, Viral↗
PubMed1984

Strategies for the economic preparation of Epstein-Barr virus proteins of diagnostic and protective value by genetic engineering: a new approach based on segments of virus-encoded gene products.

Immunoprecipitation of Epstein-Barr viral proteins with various sera from normal adults, patients with fresh infectious mononucleosis or nasopharyngeal carcinoma was used to identify antigens which are of importance in the determination of immune status and characteristic of a particular disease. Some genes coding for of these antigens have been localized on the Epstein-Barr virus (EBV) genome by hybrid-selected translation. With the use of sequence data, these genes could then be subcloned from EBV DNA and expressed in eukaryotic and prokaryotic cells. Data on the expression are presented and the application of the methods described for the production of diagnostic reagents and vaccines is discussed.

Antibodies, Viral↗
PubMed1984

[Hypophosphatemic rickets in premature infants weighing less than 1500 grams on oral and parenteral feeding].

The effect of mode of feeding on the development of rickets in very-low-birth-weight (VLBW) infants in spite of regular vitamin D supplementation was examined. Parenterally fed infants develop rickets more often than orally fed ones in spite of sufficient vitamin D supplementation. On total parenteral feeding hypophosphatemia was observed because phosphate supplementation was significantly lower than on oral feeding or in the intrauterine growing fetus of comparable gestational age. Adequate parenteral phosphate supplementation can prevent rickets.

Humans↗
PubMed1984

[Time of death in diseases with lethal outcomes in a pediatric surgery department and a pediatric hospital].

Thirteen hundred twenty five deaths in children were investigated at the Dept. of Pediatric Surgery of the University Children's Hospital Munich and the University-Children's Hospital Giessen in order to evaluate a possible correlation between time of death and time during the day. Subdividing according to age groups and pediatric-surgical and pediatric cases, there was no accumulation of deaths between 2 and 6 o'clock a. m. as could have been expected according to Aschoff. On the other hand, between 12 und 3 o'clock p. m. there was an increase of deaths which was partly statistically significant and in accordance with Aschoff's findings. One can deduce that during the early afternoon hours technical and nursing potentialities for compensation were not fully used, whereas this seemed to be the case during early morning hours. Therefore it should be attempted to optimize personal and technical expenditures particularly during the early afternoon hours.

Child↗
PubMed1983

The 'M2' electromyographic response to random perturbations of arm movements is missing in long-trained monkeys.

Adult monkeys who have been under training over a long period of time show a loss of the M2 component in their biceps electromyographic response to brief, random perturbations of an alternating arm movement, the M1 component being apparently enhanced. These changes of the stretch-induced responses indicate a long-term plasticity of the sensorimotor system of monkeys. This result also provides hints for the origin and possible functional significance of the short- and long-latency components of the electromyographic response in subjects with less experience.

Animals↗
PubMed1983

Urothelial dysplasia concomitant with bladder tumours as a determinant factor for future new occurrences.

Of 53 patients with primary bladder tumours of categories T1 or T2 about 50% had concomitant urothelial dysplasia, either carcinoma-insitu or less dedifferentiated dysplasia graded as grade II. In a follow-up study of these patients treated with transurethral resection alone, it was found that new occurrences had developed in 87% of patients with concomitant urothelial dysplasia, compared with 26% of those without dysplasia. Most new occurrences developed within 6 months of initial tumour resection. A new invasive tumour developed in all patients with concomitant carcinoma-in-situ, emphasising the serious prognostic significance of that entity. Thus, urothelial dysplasia concomitant with a bladder tumour is an important determinant factor for future new occurrences.

Biopsy↗
PubMed1983

Prognostic factors in local surgical treatment of invasive bladder cancer, with special reference to the presence of urothelial dysplasia.

Thirty-three patients with bladder cancer of categories pT1 or pT2 were treated by transurethral resection alone. At the initial diagnosis random preselected site mucosal biopsies were obtained to demonstrate the presence or absence of concomitant urothelial dysplasia. A statistically significant (P less than 0.01) relationship was found between the presence or absence of concomitant urothelial dysplasia and the development of new occurrence or the absence of recurrence at cystoscopic follow-up. Four of six patients with concomitant carcinoma in situ developed invasive bladder cancer within 6 months demonstrating the serious prognostic significance of this entity. Thus, the presence or absence of concomitant urothelial dysplasia at the initial diagnosis of invasive bladder cancer seems to be an important prognostic factor for future new occurrences.

Adult↗
PubMed1983

Human spontaneous lymphocyte-mediated cytotoxicity (SLMC) against malignant and normal tissue-derived target cell lines tested in autologous and allogeneic combinations by the microcytotoxicity assay.

Effector cell types and effector mechanisms of human spontaneous lymphocyte-mediated cytotoxicity (SLMC) were studied in a 44-h microcytotoxicity titration assay. Peripheral blood lymphocytes from cancer patients and controls were used as effector cells either unfractionated or after fractionation by rosetting techniques or affinity chromatography. The possible immunoglobulin dependency of the reactions was studied by incorporation of specific Fab fragments of rabbit anti-human IgG antibodies in the incubation mixtures. Twelve different target cell lines of either high or low sensitivity to SLMC and with or without easily detectable HLA antigens were used. Most of the target cells were cell lines derived from transitional cell carcinoma of the urinary bladder (TCC). Both allogeneic and autologous lymphocyte target cell combinations were tested. Although high- and low-sensitivity target cells differed significantly in susceptibility to lysis, the predominating SLMC was displayed by Fc-receptor-positive lymphocytes in both allogeneic and autologous combinations. Addition of the Fab anti-immunoglobulin reagent to the incubation mixtures resulted in strong inhibition of cytotoxicity regardless of the type of target cells used and in allogeneic as well as in autologous lymphocyte target cell mixtures. However, in some combinations no inhibition was seen and inhibition was usually not complete, suggesting that both immunoglobulin-dependent (i.e., ADCC-like) and immunoglobulin-independent mechanisms were involved in the cytotoxicity reactions. The results of the microcytotoxicity assay were compared with those obtained with aliquots of the same lymphocytes and target cells in an 18-h 51Cr-release assay. While similar results were obtained with high-sensitivity target cells, with low-sensitivity targets and in some autologous combinations the two assay systems registered lymphocyte/target cell interactions which differed with regard to specificity, effector cell type, and immunoglobulin dependency.

Cell Line↗
PubMed1983

Characterization of Herpesvirus saimiri and Herpesvirus ateles structural proteins.

The structural proteins of Herpesvirus saimiri strains 11 and 11 att and of Herpesvirus ateles strains 73 and 810 were characterized by electrophoresis in SDS-polyacrylamide gels. For H. saimiri 21 virus structural proteins could be identified with molecular weights ranging from 28,000 to 210,000 Da. For H. ateles 810 and H. ateles 73, 20 polypeptides were characterized. Using lactoperoxidase for iodination of surface proteins and immunoprecipitation, 5 polypeptides could be identified as envelope and 4 as capsid surface proteins.

Capsid↗
PubMed1983

Quantitative measurements of contact interactions between solid surfaces--a novel method for characterizing surface properties of biomaterials.

A method developed in colloid chemistry for quantitative measurements of adhesion forces in dispersive systems was adapted for the characterization of surface properties of biomaterials in electrolyte solutions and in the presence of macromolecular adsorption layers. The adhesion force between a reference surface (glass) and different polymers (polyurethanes and cellulose derivatives) was found to be dependent on the immersion time of polymers in electrolyte and on the formation of adsorption layers of serum albumin and fibrinogen. It was concluded that the adhesion forces measured can be considered as a further complex interfacial parameter reflecting such microscopic surface properties of biomaterials, which are responsible for biocompatibility.

Adhesiveness↗
PubMed1983

Electrokinetic properties of polymer and glass surfaces in aqueous solutions: experimental evidence for swollen surface layers.

Streaming potential and streaming current measuring techniques have been applied to polymer and glass surfaces to study solid/liquid interface electrical properties. The streaming current technique provides a reliable electrokinetic potential value, preexcluding surface conduction. A combination of both techniques results in experimental evidences for swollen, gel-like layers at (even apolar) polymer surfaces. Protons and hydroxide ions are the potential-determining ions indicated by the dependence of streaming potential on pH. Human serum albumin adsorption at a glass surface is discussed in terms of spatial distribution of the fixed macromolecular electric charges.

Adsorption↗
PubMed1983

An immunoprecipitation blocking assay for the analysis of EBV induced antigens.

A technique for the analysis of EBV antigens in extracts of unlabelled EBV infected cells has been developed. Using this technique we have demonstrated that the EBV early antigen complex consists of several proteins and is not completely expressed in chemically induced Raji cells. Studies with a range of sera from patients with infectious mononucleosis and nasopharyngeal carcinoma have shown that despite similar titers by the indirect fluorescent antibody test different populations of proteins were precipitated by different sera.

Antigens, Viral↗
PubMed1983

Comparative studies of normal, 'spontaneously' transformed and malignant human urothelium cells in vitro.

In numerous in vitro studies of cell-mediated cytotoxicity directed against transitional cell carcinomas (TCC) urothelial cells of normal origin have served as control material. In the present work, which includes 13 human bladder cell lines of non-malignant or malignant origin, a comparison was made of morphology, chromosomal mode, growth fraction and tumorigenicity in nude mice. Signs of apparently spontaneous transformation were seen in two cell lines of non-malignant origin. The possibilities for cross-contamination as an explanation of these signs of 'spontaneous' transformation are discussed. During these studies radiation-dependent cytotoxicity of disposable microtissue culture plates was revealed as another important source of error.

Aged↗
PubMed1983

Carnitine deficiency in premature infants receiving total parenteral nutrition: effect of L-carnitine supplementation.

To investigate whether L-carnitine supplementation may correct nutritional carnitine deficiency and associated metabolic disturbances in premature infants receiving total parenteral nutrition, an intravenous fat tolerance test (1 gm/kg Intralipid over four hours) was performed in 29 premature infants 6 to 10 days of age (15 receiving carnitine supplement 10 mg/kg . day L-carnitine IV, and 14 receiving no supplement). Total carnitine plasma values were normal or slightly elevated in supplemented but decreased in nonsupplemented infants. In both groups, fat infusion resulted in an increase in plasma concentrations of triglycerides, free fatty acids, D-beta-hydroxybutyrate, and short-chain and long-chain acylcarnitine, but total carnitine values did not change. After fat infusion, the free fatty acids/D-beta-hydroxybutyrate ratios were lower and the increase of acylcarnitine greater in supplemented infants of 29 to 33 weeks' gestation than in nonsupplemented infants of the same gestational age. This study provides evidence that premature infants of less than 34 weeks' gestation requiring total parenteral nutrition develop nutritional carnitine deficiency with impaired fatty acid oxidation and ketogenesis. Carnitine supplementation improves this metabolic disturbance.

Carnitine↗