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Biomedical subjects

B Wagner

Publications and source records attributed to B Wagner.

At least 217 records · Page 12Linked to original sources
PubMed1987

Treatment of relapsing acute lymphoblastic leukemia in childhood. II. Experiences with 45 first bone marrow and 24 isolated central nervous system relapses observed 1981-1984.

Of 45 children with ALL who had a first hematological recurrence between 1981 and 1984, 33 relapsed while still on treatment and 12 after cessation of therapy. Of the former 1 of 16 high risk (initial WBC greater than or equal to 20 x 10(9)/l and/or enlargement of the mediastinum) and 5 of 17 low risk patients (initial WBC less than 20 x 10(9)/l and no enlargement of the mediastinum), of the latter 6 patients survived after a minimum follow-up of 20 months. During the same time period, a first isolated CNS relapse was observed in 24 children of whom 16 survived. These results suggest that at the time of evaluation 1. the prognosis of children with ALL in first hematological relapse during the years 1981-1984 was not significantly different from that of similar children treated earlier; and 2. the prognosis of children with isolated CNS relapse had improved.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Interference of phorbolesters with endothelium-dependent vascular smooth muscle relaxation.

Histamine-induced endothelium-dependent relaxation (EDR) in the pulmonary artery was inhibited in a concentration-dependent manner by the phorbolester phorbol 12,13-dibutyrate (PDBu) (IC50: 70 nM) whereas EDR occurring in response to ionophore A 23187 was not affected by PDBu. The phorbolester 4 alpha-phorbol 12,13-didecanoate (4 alpha-PDD), which does not activate protein kinase C (PKC), was without effect on receptor- or ionophore-induced EDR. The observed inhibition of signal transduction by PKC activation is suggested to reflect phosphorylation of the GTP binding protein Ni.

Animals↗
PubMed1986

Albumin bound to the surface of M protein-positive streptococci increased their phagocytosis by human polymorphonuclear leukocytes in the absence of complement and bactericidal antibodies.

Using a phagocytosis assay (Leijh 1980, Infect. Immun. 30, 421), determination of chemiluminescence, and transmission electron microscopy, the influence of the binding of albumin to M protein-positive group A streptococci on their phagocytosis by human polymorphonuclear leukocytes (PMNL) was investigated. Coating of streptococci with albumin in the absence of other serum components enhanced phagocytosis but not killing of the bacteria. Complement had no additional effect on engulfment. Fibrinogen reduced the enhancing effect of albumin. Albumin had no additional effect on the high phagocytosis rate of an M-protein-negative strain. It could be demonstrated that human PMNL bound human serum albumin-gold conjugate. The results are discussed with regard to the role of plasma proteins in the phagocytosis of streptococci under in vivo-conditions.

Antibodies, Bacterial↗
PubMed1986

Resinless section electron microscopy of HeLa cell mitotic architecture.

The use of resinless sections extends embedment-free electron microscopy to the cytoskeleton of thick specimens. Here we examine HeLa cells rounded at mitosis. Extraction of mitotic HeLa cells with Triton X-100 removes lipids and soluble proteins, leaving the cytoskeletal framework and spindle apparatus. After fixation, the samples are embedded and sectioned, and the temporary embedding resin is removed for direct visualization in the electron microscope. The micrographs show that the cytoskeletal framework, chromosomes, spindle, and centrioles form an interconnected entity. The pericentriolar region, indistinct in conventional micrographs, appears composed of distinct fibers interconnecting the spindle microtubules and centriole. The resinless sections also reveal characteristic lacunae at late anaphase/early telophase. These probably result from reformation of the interphase cytoskeleton lagging reassembly of the nucleus.

Centrioles↗
PubMed1986

Receptors for erythrogenic toxin A of Streptococcus pyogenes on human peripheral blood lymphocytes and other blood cells.

The binding of erythrogenic toxin A (ETA) of group A streptococci on human peripheral blood cells was demonstrated light- and electronmicroscopically by labelling with ETA-gold. Double labelling experiments of lymphocytes and the use of purified T-lymphocytes revealed that the ETA-receptor was confined to T cells. Besides lymphocytes, monocytes and especially granulocytes and thrombocytes showed a significant ETA-gold labelling. The lymphocyte ETA-receptor was found to be not sensitive to trypsin and neuraminidase and was not identical with the receptors for concanavalin A, Helix pomatia-lectin and sheep erythrocytes.

Adult↗
PubMed1985

The influence of penicillin on growth and morphology of Streptococcus pyogenes in vivo.

The influence of penicillin (pc) on the growth, phagocytosis and killing of Streptococcus pyogenes was studied for an M protein positive (M+) and an M protein negative (M-) strain in vivo as well as in vitro. In vivo studies were based on a tissue cage model and the analyses were performed by CFU determinations and electron microscopic investigations. The M- strain was easily phagocytized with and without pc, but killing only occurred after pc treatment and thus the number of viable bacteria rapidly decreased under the influence of pc. M+ streptococci were not reduced in numbers by pc-treatment in vivo, but morphological changes and at high pc concentrations, phagocytosis could be seen. When this strain (M+) was cultivated in the absence of pc, the phagocytic cells were totally destroyed - a reaction that was prevented by penicillin. Variations in surface morphology of the two strains seem to influence the differences in sensitivity to penicillin, phagocytosis and killing.

Animals↗
PubMed1985

Pubertal spurts in cranial base and mandible. Comparisons within individuals.

Serial data from cephalometric radiographs were analyzed for 34 boys and 33 girls who had cephalometric radiographs annually near each birthday from at least age 7 through 18 years. Spurts were defined for this study as increases between successive cranial base increments that exceeded 0.75mm/year in boys or 0.5mm/year in girls. The corresponding criterion for the mandible was 1.0mm/year in either sex. Pubescence was defined as the 4- year period spanning 2 years before and after peak height velocity. Spurts during pubescence were common, tending to occur about 1.6yr earlier in girls than boys. The mean increments at first pubertal spurt (FPS) and the mean sizes of FPS were about 25% to 33% greater in the boys than in the girls. The rate of growth during the year before FPS tended to be greater in the girls, while in the year after FPS it tended to be greater in the boys. The timing of FPS in either cranial base of mandible was not closely related to the onset of ossification in the ulnar sesamoid, the age at peak height velocity, or age at menarche. FPS generally occurred after the onset of ossification of the ulnar sesamoid, but before peak height velocity and menarche. There was no evidence of difference between craniofacial EPS in children who passed rapidly or slowly through pubescence, nor was any difference noted between the size of pubertal spurts in tall or short boys. larger total increments after peak height velocity were found in the short boys. Significant correlations were identified between the cranial base and the mandible in the timing but not in the magnitude of FPS. The children were approximately equally divided between those in whom cranial base spurts occurred first, those in whom mandibular spurts were first, and those in whom FPS occurred in both areas within the same annual interval.

Adolescent↗
PubMed1985

A sialic-acid-specific lectin from Cepaea hortensis that promotes phagocytosis of a group-B, type-Ia, streptococcal strain.

Group-B streptococci that possess a type-specific surface polysaccharide undergo phagocytosis only in the presence of antibodies to this, and complement. The snail Cepaea hortensis forms a lectin that is specific for sialic acid; treatment with this promoted the phagocytosis of a group-B streptococcus of serotype Ia (strain O90) in the absence of opsonic antibodies. The effect of the lectin was dose-dependent and required the presence of complement. The specificity of the lectin reaction for sialic acid was proved by the inhibition of phagocytosis by bovine submaxillary mucin. The participation of complement in the reaction was confirmed by demonstrating that C3 was bound to the surface of lectin-treated cells.

Animals↗
PubMed1985

Binding of horse-spleen ferritin to group A streptococci.

Receptors for horse-spleen ferritin were found on group A streptococci. Both electron microscopic and chemical investigation of Streptococcus cells treated with ferritin showed that M + variants of group A streptococci were able to bind substantially more ferritin than M - variants of the same serotypes. Ferritin receptors were located on the tops of filamentous protrusions of Streptococcus cell walls and only on the outer surface of isolated cell walls. Trypsin treatment destroyed the ferritin-binding capacity of streptococci completely, while mild pepsin treatment left the ferritin receptors undisturbed, or uncovered additional ones. The ferritin receptors were not identical with receptors for the Fc-portion of swine IgG. The finding of ferritin receptors on bacteria necessitates careful interpretation of results obtained by immunoferritin localization techniques.

Animals↗