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Biomedical subjects

H Ludwig

Publications and source records attributed to H Ludwig.

At least 397 records · Page 22Linked to original sources
PubMed1978

Behavior alterations in tree shrews (Tupaia glis, Diard 1820) induced by Borna disease virus.

Intracerebral injection of Borna disease virus in tree shrews led to a persistent infection that sometimes resulted in clinical symptoms and/or specific alterations in the animals' behavior. Whereas infective virus in the brain and in the serum antibodies were always present after infection, only some of the animals showed signs of clinical disease and behavior changes. Animals kept in pairs showed especially obvious behavior alterations expressed as an exaggeration of all the components of normal social behavior. The division of the roles between males and females was seriously disturbed. The breeding behavior of females was especially impaired, although no stress factors were given and the animals were obviously in good physical condition. Some females that were maintained solitarily showed considerably exaggerated spontaneous locomotor activities (hyperactivity) 4 weeks after infection, followed by a phase of clinical neurologic symptoms (decline phase), spatial and temporal disorientation, and alterations in comfort behavior. Following a slow recovery the animals remained unusually docile and were much less timid than before infection. A recurrence of the clinical illness is possible, as shown by the occurrence of a second decline phase. All the behavior alterations can be interpreted as a disturbance in the balance of approach and avoidance. In paired animals this imbalance results in interference with normal sociosexual behavior. These alterations indicate that BD preferentially involves the limbic system, an interpretation supported by the results of neuropathologic investigations.

Animals↗
PubMed1978

Volume changes during enzyme reactions. The influence of pressure on the action of invertase, dextranase and dextransucrase.

The pressure dependence of the maximum velocities and the Michaelis constants for the enzymes invertase and dextranase was measured up to 1400 bar. The corresponding activation volumes deltaV not equal to c and deltaV not equal to Km proved to be independent of pressure. Together with data from other sources the meaning of deltaV not equal to c and deltaV not equal to Km is established and the volume profiles of the reactions are constructed. These profiles are similar in contour to the volume profile of the dextran formation catalyzed by the enzyme dextransucrase, but the amount of the volume changes is very much larger for dextransucrase. The evaluation of salt effects shows, that for all three enzymes solvent interactions are not important in explaining the results. The reaction mechanisms seem to be governed by conformation changes of the enzymes. The larger effects in dextransucrase are explained by the produced dextran chain remaining tightly bound to the enzyme and being transported relative to the enzymes position in each reaction cycle.

Dextranase↗
PubMed1978

Assessment of hormone loss through hemofiltration.

The concentrations of testosterone, cortisone, gastrin, insulin, gastric inhibitory polypeptide (GIP), somatomedin B, parathyroid hormone (PTH), human growth hormone (HGH) and thyroid stimulating hormone (TSH) have been determined in the plasma and the ultrafiltrate of five uremic patients undergoing intermittent hemofiltration treatment. There was a considerable loss of gastrin, insulin, GIP, somatomedin B and PTH by hemofiltration treatment. The plasma concentrations, however, did not decrease except for immunoreactive-PTH (IR-PTH) which returned from elevated to normal levels. Cortisone, HGH and TSH concentrations in the ultrafiltrate were below the measureable range. A significant elimination of 11-hydroxylated androstans by hemofiltration may have a positive effect on the disturbed steroid metabolism. Results indicate that hemofiltration does not cause a hormone deficiency syndrome. On the contrary, the loss of degradation products of hormones with disturbing biological activity may be a favorable effect of the hemofiltration treatment.

Cortisone↗
PubMed1978

Identification of a common antigen of herpes simplex virus bovine herpes mammillitis virus, and B virus.

In immunoelectrophoretic analyses one common antigen was demonstrated in antigen preparations from herpes simplex virus types 1- and 2- (HSV-1 and HSV-2), bovine herpes mammillitis (BHM) virus-, and B virus-infected cells solubilized by Triton X-100. The antigen was also demonstrated in solubilized purified HSV-1 and BHM virus. The common antigen was identified as antigen 11 of HSV-1 or HSV-2. Differences were found in the polypeptide composition of the related antigens when isolated from the four different herpesviruses, but a glycopolypeptide with a molecular weight of 125,000 was present in each of the four different antigen preparations, indicating that this polypeptide carried the common antigenic determinants.

Antigens, Viral↗
PubMed1978

[Cellular immune reactivity in patients with multiple myeloma].

The ConA-, PHA- and PWM-induced lymphocyte transformation rates were significantly decreased in 19 patients with multiple myeloma. Lymphocyte-inherent defects rather than serum factors seem to account for this decreased lymphocyte reactivity. In 58% of the patients a pathologically increased ConA-induced suppressor cell activity, which was negatively correlated with the non-paraprotein IgM-concentration, was found.

Humans↗
PubMed1978

[New viewpoints on the pathogenesis of diabetes mellitus].

Diabetes mellitus is a syndrome characterised primarily by an increase in blood glucose and an absolute or relative deficiency of insulin. Etiologically, it is a complex disorder because many different genetic, environmental, immunological, metabolic and hormonal influences interact to produce the clinical picture diabetes. By introducing HLA typing in diabetes research in the last four years, it became possible to clearly distinguish between the juvenile-onset, insulin-dependent type and the non-insulin-dependent, maturity-onset type of diabetes mellitus. On the basis of this and other evidence, at least five nosologically distinct types of diabetes can be identified.

Autoimmune Diseases↗
PubMed1978

[Identification of thyroglobulin-binding cells in the blood of Hashimoto patients (author's transl)].

We developed a new method for demonstration and enumeration of antigen-binding cells, the principle and application of this method is demonstrated using peripheral blood lymphoid cells from Hashimoto patients, non-Hashimoto, non Graves' disease goiter patients and in patients without thyroid disease. A significantly higher number of thyroglobulin-binding cells was observed in the peripheral blood of Hashimoto patients as compared to members of the two other groups. The results of the FICA-tests were compared to conventional serological data of the individual patients.

Aged↗
PubMed1978

Humoral antibacterial immunity in first degree relatives of insulin-dependent diabetics.

Humoral immunity to bacterial antigens was investigated in 68 tissue typed and glucose tolerance tested first degree blood relatives of insulin dependent diabetics (IDD). The data were compared with those obtained in 60 IDDs and in 55 healthy controls. The prevalence of bacterial antibodies to E. coli, staphylococci, pertussis and diphtheria toxins were just slightly, but not significantly reduced in the blood relations compared with controls. Incidence of antibacterial antibodies was almost identical in blood relations with impaired and in those with normal glucose tolerance. By contrast, antibody formation to E. coli and staphylococci (p less than 0,0005, p less than 0,0005) respectively was significantly impaired in IDD. No correlation between genes of the major histocompatibility complex and humoral antibacterial immunity could be observed in IDD and blood relations. In conclusion, antibacterial antibody formation was found to be severely impaired in IDD patients but to be almost normal in blood relations of insulin dependent diabetics. These findings suggest that the humoral antibacterial immunodeficiency observed in IDD is a disease associated process probably independent of major histocompatibility complex linked genes.

Adult↗