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Biomedical subjects

H Köhler

Publications and source records attributed to H Köhler.

At least 523 records · Page 29Linked to original sources
PubMed1975

Cerebral toxicity of penicillins in relation to their hydrophobic character.

The neurotoxic effects of ticarcillin, methicillin, phenthicillin, oxacillin, cloxacillin and dicloxacillin were studied in the conscious rabbit. During and after intravenous administration of 1.2 and 2.4 g/kg, resp., over 50 min the blood concentrations of the drugs were determined and the neurotoxicity assessed by continuous recording of the electroencephalogram. The hydrophobia of the penicillins was characterized by determination of their partition coefficients between isobutanol and buffer solution pH 7.4. The penicillins showed quite different neurotoxic properties. A close correlation (r = 0.928) was found between the neurotoxic potency of the penicillins and their partition coefficients. With increasing hydrophobia the neurotoxic potency increased in the following sequence: Ticarcillin, methicillin, oxacillin, phenethicillin, cloxacillin, dicloxacillin. It can be concluded, therefore, that determination of the partition coefficient of a penicillin gives valuable information on the neurotoxicity to be expected. The introduction of a neurotoxicity quotient revealed that penicillins may be divided into two groups: less neurotoxic penicillins with a partition coefficient below 1.0 and highly neurotoxic penicillins with a partition coefficient above 1.0.

Animals↗
PubMed1975

[Sterno-costo-clavicular hyperostosis (author's transl)].

A case is described in which bilateral subclavian vein occlusion was caused by fusiform expansion of the clavicle with hyperostosis, ankylosis of the sterno-clavicular joint, widening and thickening of the sternum and ossification of the costal cartilage of the first ribs. Histologically this proved to be due to an hyperostotic spongiosclerosis.

Ankylosis↗
PubMed1975

Cell electrophoretic studies on the cellular immune response to Candida albicans in rabbits.

Rabbits were sensitized intracutaneously with Candida albicans total antigen by a series of booster injections. The electrophoretic migration time of lymph node lymphocytes was related to the time after injection. Two lymphocyte sub-populations could be distinguished. The proportion of each, changed during the course of the immune response. Characteristic changes also took place after in vitro incubation with Candidin. The results have been compared with agglutination titers and are discussed in relation to bursa and thymus-derived cells. The electrophoretic method may be valuable for the diagnosis of candidiasis.

Animals↗
PubMed1975

[Antibodies against hepatitis B (surface) antigen in patients with hepatitis and other groups of epidemiologic interest (author's transl)].

Sera of patients with hepatitis A and B and of patients in a hemodialysis unit as well as sera of drug addicts were examined for the presence of antibodies against hepatitis B (surface) antigen (HBsAg) employing the Ausab test - a new radioimmunoassay. In 79.3% of the hepatitis B patients the occurrence of antibodies against HBsAg (anti-HBsAg) was noted after the HBsAg had disappeared. In hepatitis A patients anti-HBsAg could be detected in 15.5% (adults) and in 4.6% (children) respectively. These antibodies persisted over an observation period up to 15 months and were not connected with the apparent illness at the time of the examination. These results are rather an indication of the frequency of antibodies against HBsAg in the normal population. In two patients with hepatitis A a delayed antibody reaction similar to that seen in hepatitis B patients was observed though HBsAg could not be detected (Ausria 125 test). It is assumed that these patients suffered from hepatitis B which on the basis of the negative HBsAg status was diagnosed as hepatitis A. According to that observation not all cases of HBsAg negative hepatitis are necessarily of type A but occasionally of type B not detectable by means of HBsAg assay at that time. Drug addicts without hepatitis at the time of investigation showed 50.8% anti-HBsAg, in 24.3% HBsAg was detected by means of the Ausria 125 test. In 19 drug addicts with positive antigen or antibody status a history of hepatitis was established. Patients of the hemodialysis unit were found to be HBsAg carriers in 9.2% and anti-HBsAg carriers in 53.5%. The data obtained from drug addicts and dialysis patients point to a high risk of infection in both groups and to a frequent contact with HBsAg (booster) in dialysis units. The combined application of sensitive tests for the detection of antigen and antibodies (radioimmunoassays) with regard to epidemiological and anamnestic studies is recomended.

Adult↗
PubMed1975

[The preparation and characterization of transfer factor (author's transl)].

A transfer factor (TF) was prepared and characterized from the leucocytes of Mantoux-positiv donors using a variety of techniques. The results allowed the following conclusions: Whilst extraction by dialysis and phenol (without precipitation) led to nearly the same positiv immunological activities, when assayed in the MEM-test, phenol extracts subjected to RNA-precipitation lost considerable activity. The residual activity was associated with the lower molecular fractions, and RNA itself has shown no activity. Residues after leucocyte dialysation have also shown considerable TF-activity when extracted by phenol. It was found that phenol extraction followed by gel filtration allowed recovery of considerable quantities of active TF, confined to several specific filtration fractions. Combination of active and inactive gel filtration fractions suggested that there existed an inhibitory factor within the extracted leucocyte preparations. This modified preparation and purification procedure may allow the preparation of TF for therapeutic purposes.

Chromatography, Gel↗
PubMed1975

Specific suppression of the antibody response in vitro by serum from paralyzed mice.

BALB/c mice immunized with either the whole vaccine or the C-polysaccharide obtained from the R36A strain of pneumococcus produce antibody to phosphorylcholine. Mice injected i.v. with a single high dose of the C-polysaccharide are specifically unresponsive to immunization to phosphorylcholine for many months and are considered paralyzed. The induction of paralysis does not eliminate cells reactive to phosphorylcholine; however, serum from paralyzed mice specifically suppresses the response of cultures of normal spleen cells to phosphorylcholine. Paralyzed mice have an early low antibody response to phosphorylcholine and to the receptor for phosphorylcholine as indicated by plaque-forming cell assays. The factor or factors present in serum which may suppress cultures, and, by presumption, be responsible for paralysis are complexes of antigen, antibody, and antibody to the receptor for phosphorylcholine.

Animals↗
PubMed1975

Anti-receptor antibody. I. Isolation and characterization of the immunoglobulin receptor for phosphorylcholine.

We have demonstrated a phosphorylcholine-binding protein in lysates from radioiodinated splenocytes of immunized mice. Immunoprecipitation with anti-receptor antibody of lysates from splenocytes obtained from animals undergoing a primary response or from mice immunized 4 to 6 months earlier with antigen demonstrated that this protein contained H and L chains. Therefore, we have isolated an antigen-specific receptor from the surface of spleen cells from both immunized and "memory" animals. This receptor Ig comprises approximately 10% of total cell surface Ig.

Animals↗
PubMed1975

Anti-receptor antibody. II. Induction of long-term unresponsiveness in neonatal mice.

We have examined the ability of anti-receptor antibody (ARA) to induce specific unresponsiveness to the hapten, phosphorylcholine (PC), in neonatal and adult mice. When ARA is given to adult mice, suppression is of short duration. Cells from such mice are responsive in vitro, indicating that suppression in vivo is probably due to blockade of receptors by persisting ARA. ARA given to neonatal mice induces long-term unresponsiveness. The mice apparently have decreased numbers of PC-responsive cells, since cells from such mice are unresponsive both in vitro and in adoptive transfer. Furthermore, cells from neonatally suppressed animals do not suppress the response of normal cells either in vitro or in adoptive transfer, indicating that unresponsiveness is most likely not due to active suppression. We therefore conclude that ARA given to neonates depletes the clone of receptor-bearing cells at the time ARA is given. Clonal depletion may result from antibody-dependent cell mediated cytotoxicity.

Animals↗
PubMed1975

Antigenic subgroups of hepatitis B (surface) antigen in Berlin (West) and their epidemiological aspects.

Sera of 334 hepatitis B patients and 118 sera of HBsAg carriers were tested for the distribution of the subgroups ad and ay by means of rheophoresis technique or solid phase radiommunoassay. The distribution of subgroups revealed a typical pattern. The ad-antigen determinant was more frequent in hepatitis B patients, blood donors and hemodialysis patients whereas the ay determinant was detected in drug users, guest workers and juveniles at a considerably higher percentage. The difference in distribution is discussed as an epidemiological phenomenon of hepatitis B virus, dependent on environmental factors characteristic for certain groups of the population. The routine testing for HGsAg subgroups is recommended as a valuable epidemiologic tool.

Adolescent↗
PubMed1975

Antigenic variation of neuraminidase of human type A influenza (H3N2) viruses isolated in Berlin (West).

After the emergence of the A/Hong Kong/1/68 (H3N2) strain of influenza virus antigenic variation of the hemagglutinin and neuraminidase antigens have been demonstrated leading to the identification of the variants A/England/42/72,a/Port Chalmers/1/73 and A/Scotland/840/74. This study describes antigenic changes of neuraminidases in influenza viruses isolated since 1968 in Berlin (West). A collection of 13 isolates of human type A influenza was studied in neuraminidase inhibition tests. The results are in line with data from other laboratories indicating a major change in the neuraminidase antigen as early as December 1969. The strains isolated at that time cross-reacted with an antiserum against the N2-Hong Kong enzyme to less than 50%. During the following years (1970 to 1972) the neuraminidase remained fairly stable. Serological cross-reactions showing 47 to 38% inhibition as compared to the homologous N2-antigen. The neuraminidase of the A/Berlin/3/72 strain revealed a close antigenic relationship to the later appearing A/Port Chalmers 1/73 variant. Two strains isolated in 1975 (January) showed an even further drift away from the then representative A/Port Chalmers/1/73 strain. The fact that the neuraminidase antigens of the Berlin viruses had changed in December 1969 may account for the severe 1969/70 influenza epidemic in Berlin affecting a large proportion of the population. Prevalent anti-neuraminidase antibodies may play a role in restricting a variant carrying a new hemagglutinin to primarily infected individuals by cross-reacting with a closely related enzyme.

Antigens, Viral↗