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Biomedical subjects

M Wagner

Publications and source records attributed to M Wagner.

At least 937 records · Page 52Linked to original sources
PubMed1987

[Tuberculin conversion rate in long-term employees of a university hospital during the period from 1975 to 1985].

During the period of 1975 until 1985 the tuberculin conversion rate has been determined for 142 persons who have been employed more than 4 years in an university hospital. The current records of the occupational medical investigation-department in which 5,700 case sheets have been stored at the beginning have been available for the selection of these subjects. After a latent period of 2.5 years 9.2% of the employees converted. The highest conversion rate of 16.7% was settled amongst those staff occupied in a lower level, e.g. craftsmen, charwomen, laundress, kitchenhelp, servants and so on. The second in high responder-quote was found in the nursing personal with 9.9% followed by the laboratory staff with 8.7%. Within the office workers no tuberculin positive reagent has been observed. Whilst the interpretation of the tuberculin conversion rate there must be taken into consideration beside the occupational dependent sensibilization against tuberculosis bacteria the non occupational contamination sources, too (like smear- and droplet infection due to usual social contacts or household-contacts resp.).

Hospitals, Teaching↗
PubMed1987

[Occupational medicine studies of 7 ethylene oxide-exposed endoscopy nursing professionals].

For 7 working days running the ethyleneoxide (EtO) concentration has been determined in a medium sized sterilization plant of a medical endoscopy department. Sampling was taken from passive collectors of 3 M. The concentrations were 4 times (= 57% of the whole measured values) under the detection limit of 0.25 ppm = 0.46 mg/m3 in accordance with an eight hour shift; the EtO-level of 1.5, 2.1 and 9.2 ppm stayed for the remaining cases. Consequently the present valid TRK-value of 3 ppm was exceeded only one time. The exposition duration was between 0.6 and 13 years (median 5.5 years) for these 7 participants with a mean age of 33.4 (median 5.5 years). On the occasion of routine laboratory checks which included the analysis of important hematological, hepatological, nephrological and immunological values, no EtO-exposure has been found which was in causal connection with pathological findings. The search for specific RAST-IgE-antibodies against EtO in serum passed negatively. The enzyme activities of the gamma-GT correlated approximately with the anamnestic mentioned alcohol quantity, consumed daily.

Adult↗
PubMed1987

[Functional anatomy of the knee joint].

Detailed and comprehensive knowledge of the knee joint's anatomy is an essential prerequisite for understanding of the joint's function and its pathophysiology, for precise diagnosis, and for satisfactory treatment of lesions of the joint capsule and ligaments. Thus, anatomy represents "the key to the knee".

Biomechanical Phenomena↗
PubMed1987

[Differential treatment of post-traumatic carpal tunnel syndrome].

The pathogenesis and treatment of posttraumatic compression of the median nerve in the carpal canal are analysed in 36 patients. Nine patients had mal-union of a Colles' fracture. In these patients the symptoms of median nerve compression were completely relieved by correction osteotomy of the radial metaphysis, which also improved radiocarpal joint function. At follow-up examination after four years the results were satisfactory and the median nerve appeared normal in clinical and electro-physiological tests. In the other twenty-seven patients there had been a Colles' fracture in seventeen, healed with a deviation of less than 10 degrees; a carpal bone fracture in three cases; in seven patients no osseous lesion was found. In these patients the flexor retinaculum was split and resected. An anterior callus was removed in three cases. At reexamination after four years four patients still noticed diminished sensibility in the median nerve distribution, and in four cases there was wrist joint pain in relation to exercise.

Adult↗
PubMed1986

Purification of a polypeptide complex (p52) belonging to the D-subspecificites of Epstein-Barr virus-induced early antigens.

A two-dimensional immunoblot analysis of chemically induced EBV DNA carrying Burkitt's lymphoma cell lines shows besides a large number of minor components at least two major groups of polypeptides: the most prominent group of polypeptides is observed in the range of 48 to 58 kDa (pI 4.5 to 8.5) and another group at 38/36 kDa (pI 4.4). A polypeptide complex (p52) belonging to the Epstein-Barr virus (EBV)-induced early antigen complex (EA) has been isolated from IdU-induced Raji and B95-8 cells as well as from n-butyrate-induced P3HR-1 cells. The p52 polypeptides have been purified by chromatography on Blue-, DEAE-, CM-, and Phenyl-Sepharose. The purification of these components of the EA complex was monitored by ELISA and by two-dimensional immunoblots using a well-characterized high anti-EBV positive human serum. The isolated polypeptides have an apparent mol wt of about 52,000 Da as determined under nondenaturing conditions by gel filtration chromatography on Sephacryl S-300. One- and two-dimensional immunoblots show a major group of polypeptides of 52 kDa (pI 8.5 to 5.5) with EA activity and some minor components with smaller size up to 40 kDa. The latter seem to be generated by limited proteolysis of p52 polypeptides. The EA activity of the isolated polypeptides could be confirmed by their reaction with IgG anti-EA positive as well as IgA anti-EA positive sera by ELISA. The purified polypeptide complex did not react with anti-EA-D negative, anti-EA-R positive sera obtained from patients with African Burkitt's lymphoma, suggesting that these polypeptides belong to the EA-D complex. The monoclonal antibody R3 reacted with the isolated 52 kDa components of EA suggesting a common epitope present on these polypeptides, the same result was obtained with three rabbit sera produced against the isolated polypeptide complex.

Antibodies, Viral↗
PubMed1986

Anatomical bases of patellar tendon grafts used in anterior cruciate ligament reconstruction.

In 24 fresh specimens the blood-supply of the infrapatellar fat-pad was investigated by injection. In some of the specimens, Clancy's pedicled patellar tendon graft for anterior cruciate ligament reconstruction had been performed before injection. The fat-pad is supplied by vessels forming a plexus supplying the tendon. In the tendon grafts injected after Clancy's procedure, no vessels were found penetrating the patellar tendon at its patellar and tibial attachments. Filled vessels were found by histologic methods and the Spalteholz technique.

Dissection↗
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

Evidence for reactive oxygen species inducing mutations in mammalian cells.

We have studied the mutagenicity (by selecting for mutants resistant to 6-thioguanine) and cytotoxicity (by determining cellular cloning efficiency) of physical and chemical agents in Chinese hamster ovary (CHO) cells, clone CHO-K1-BH4 (K1-BH4), and its radiation-hypersensitive transformant, AS52. AS52 cells contain a single functional copy of a bacterial gene, the xanthine/guanine phosphoribosyltransferase (gpt) gene instead of its mammalian equivalent, the hypoxanthine/guanine phosphoribosyltransferase (hprt) gene. We found that x-ray and neutron irradiations are equally toxic to both cell types; however, these physical agents are approximately equal to 10 times more mutagenic to AS52 cells than to K1-BH4 cells. Our earlier studies using Southern blot analysis showed that x-irradiation produces mostly or exclusively deletion mutations in both cell types. If reactive oxygen species mediate the mutagenic effects of radiations and chemicals, then radiomimetic compounds such as streptonigrin and bleomycin, which exert their biological effects via reactive oxygen species, and oxidizing compounds such as potassium superoxide and hydrogen peroxide should elicit a similar differential mutagenic response in both cell types. On the other hand, agents such as ethyl methanesulfonate, ICR 191, and UV light, which do not produce reactive oxygen species, should not elicit differential mutagenicity. Our results fulfill such predictions. The apparent hypermutability of AS52 cells probably results from a higher recovery of multilocus deletion mutants in AS52 cells than in K1-BH4 cells, rather than a higher yield of induced mutants.

Animals↗
PubMed1986

A search for new group-B streptococcal serotypes.

New serotypes were sought among 165 clinical isolates of group-B streptococci that were untypable by antisera for the conventional types Ia, Ib, II and III. The strains were tested for sialic acid, an integral component of the group-B streptococcal type-polysaccharides; trypsin-treated bacteria were tested by slide-agglutination with the sialic-acid-specific lectin from the snail Cepaea hortensis. Sialic acid was detected in 96 of the strains; in 95 of these, new type antigens were identified serologically (type IV, 52; provisional type V, 34; candidate type NT6, seven; provisional type V and candidate type NT6, one; candidate type 7271, one); the remaining strain was found to possess a small amount of Ia antigen. Sialic acid was not detected in 69 strains, and none of these possessed a polysaccharide type-antigen. Chemical measurement of the sialic-acid content of cultures by Aminoff's method gave results in conformity with the lectin-agglutination test and the presence of polysaccharide type-antigens.

Agglutination Tests↗
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↗
PubMed1986

[Computerized tomography in the acute diagnosis of spinal injuries].

Additional to conventional x-ray examinations, high-resolution CT has a greater impact on the diagnostic evaluation of severe spine injuries. It allows exact judgment of the condition of vertebral arch, articular processes, joints and spinal axis and therefore a better delineation of the stability or instability of spinal fractures. Intraspinal fracture of spinal stenosis and intra or paraspinal soft tissues lesions are much more easily detected. For this reasons CT-evaluation of severe spinal traumata permits earlier, much more precise and in many cases successful therapy.

Adolescent↗
PubMed1985

Functional plasticity in two afferent systems of the granule cells in the rat dentate area: frequency-related changes, long-term potentiation and heterosynaptic depression.

Monosynaptic evoked field potentials (MEFP) were recorded in the dentate gyrus of male Wistar rats upon stimulation of either the perforant path or the commissural system. While the perforant path potential exhibited in acute experiments a clear reversal point of the field excitatory postsynaptic potential (EPSP) and population spike when protruding the registration electrode from the hippocampal fissura to the hilus of the dentate gyrus, the simultaneously registered commissural potential elicited by stimulation of the contralateral hilus showed no reversal of the negative monophasic wave but merely an amplitude maximum 40 microns above the reversal point of the perforant path potential. Frequency-related changes of the MEFPs during short tetanic stimulation with 15 Hz both in acute and chronic experiments, revealed differences in the properties of the input systems in that the commissural potential exhibited a clear frequency potentiation whereas the perforant path potential showed frequency depression. Pronounced long-term potentiation of the perforant path potential induced by 4 trains of tetanizing stimuli and lasting up to 72 h was accompanied by a long-term heterosynaptic depression of the commissural potential for up to 7 days after tetanization. Both the different frequency-related changes of the inputs and the extremely long duration of the heterosynaptic depression are discussed with respect to their proposed functions in the mechanisms of functional plasticity.

Animals↗
PubMed1985

Changes in plasminogen activator activity and plasmin inhibition in the pig during experimental hypovolaemia.

A markedly decreased plasminogen activator activity (PAA) was seen in lung, heart and kidney after experimental hypovolemia in the pig. In 2 of 12 cases, an increased PAA was found in liver and spleen. In skeletal muscle, skin, sciatic nerve and in 10 of 12 cases in liver and spleen PAA was unchanged. A slightly increased plasmin inhibition was noted only in the lung. These changes in tissue PAA were reflected by an increase in the PAA of euglobulin fractions concomitant with a decrease in antiplasmin activity in the blood samples obtained during the bleeding experiments.

Animals↗