Search PubMed⌕ Search

Biomedical subjects

V Mayer

Publications and source records attributed to V Mayer.

At least 91 records · Page 5Linked to original sources
PubMed1977

[Left ventricular contraction reserve in coronary heart disease. Evaluation, quantification and prognostic value (author's transl)].

Regional and overall left ventricular contraction reserve was studied in 14 patients with coronary heart disease, in 5 healthy subjects and in 4 patients before and after aorto-coronary bypass surgery. Quantification of overall contraction was based on ventricular volumes and ejection fraction. Regional contraction reserve was calculated with the hemiaxis method and a ventricular score. Contraction reserve under nitroglycerin and in postextrasystolic beats was compared. For routine quantification of contraction reserve the ventricular score is recommended. For research purposes the hemiaxis method is to be preferred. Postextrasystolic beats are better suited for analysis of contraction reserve than are angiograms following administration of nitroglycerin. This is due to the minor expense of the procedure, furthermore, postextrasystolic beats allow better differentiation between contracting and non-contracting areas. Left ventricular contraction reserve is larger in patients with coronary heart disease, angina pectoris and ischemic reactions in the exercise ECG than in control patients. These findings are based on overall and on regional volume parameters. A quantitatively greater improvement in contraction could be provoked in the anterior wall than in the posterior wall. Regional contraction improved significantly in most cases either in the anterior wall or in the posterior wall; rarely it improved simultaneously in both left ventricular regions. In a few cases contraction deteriorated in one area with a simultaneous improvement in the opposite area. Overall and regional ventricular function, as assessed preoperatively by contraction reserve determinations could not be completely regained in normal beats after successful bypass surgery. Differences in the regional contraction reserve seemed to be mainly due to varying degrees of ischemia and scarring.

Angina Pectoris↗
PubMed1976

The opposite temperature-sensitivity character (ts) in two attenuated flaviviruses, used for human immunization: 17D yellow fever and E5"14" (Langat) viruses. A reappraisal of thoughts.

For the reproduction of the man-attenuated E5"14" clone of the Langat virus (tick-borne encephalitis complex) in pig kidney epithelial cells, the temperature of 39 degrees C was shown as restrictive, whereas it was permissive for the 17D strain of yellow fever virus and three virulent strains of tick-borne encephalitis (western subtype) virus. The temperature of 36 degrees C permitted the reproduction of all viruses studied. The implication of genetic marker studies in the assessment of human neuropathogenicity of flaviviruses is discussed.

Arboviruses↗
PubMed1976

In vitro studies on cell-mediated immune response to tick-borne encephalitis virus: findings in convalescents and human subclinical infections.

Peripheral blood leukocytes from tick-borne encephalitis (TBE) convelescents (manifest and inapparent forms) working with TBE virus-containing material and from individuals without specific serum virus neutralizing antibodies (VNA) were studied in capillary tube leukocyte migration experiments. Partially purified TBE virus preparations were used as antigen. Under standardized conditions a strong inhibitory reaction was observed in convalescents with significantly higher values in persons recovered from an abortive form of infection only. These results differed markedly from values recorded in persons without specific VNA. Significance of correlation between humoral VNA titres and the intensity of the cell-mediated component of the immune response (CM IR), as indicated by leukocyte migration inhibition (LMI) values, was less than P equals 0.25.

Adolescent↗
PubMed1976

Phenothiazine-induced alterations of immune response in experimental tick-borne encephalitis: morphological model analysis of events.

The depressive effect of trifluoperazine (TFP), a phenothiazine derivative, on the morphology of the development of immune response (IR) (humoral and cell-mediated component) was studied in mice given tick-borne encephalitis (TBE) virus, sheep red blood cells (SRBC) or the BCG vaccine. This effect was manifested by a decrease in the mitotic activity of lymphocytes and in the number of blastic transformations after antigenic stimulation. In virus-infected and TFP-given mice, lowered levels of specific virus neutralizing antibody (VNA), together with a pronounced reduction of the inflammatory response in the brain were found. No signs of cytotoxicity following administration of the drug were observed. The mechanism of the immunodepressive action of TFP are discussed.

Animals↗
PubMed1976

Experimental live tick-borne encephalitis vaccine (Labgat E5 "14" virus clone): volunteers 1 and 2 years after single-dose immunization.

Groups of volunteers given intramuscularly 5 or 6.5 dex or perorally 6.5 dex newborn mouse icLD50 of the plaquesegregated "14" clone of the Langat E5 virus strain (tick-borne encephalitis comples) were followed for periods of 12 and 24-27 months. Circulating specific virus neutralizing antibodies persisted in them in the absence of apparent reaction as evidenced by clinical, electroencephalographic and cerebrospinal fluid findings.

Administration, Oral↗
PubMed1975

Further virological and clinical investigations on the attenuated E5"14" virus from the tick-borne excephalitis complex.

A total of 22 persons, given a single intramuscular dose of 3.1 times 10(6) newborn mouse ic LD50/ml of the E5"14" virus (stored for 26 months at 4 degrees C in lyophilized state), were subjected to rigorous clinical, clinical-laboratory and virological investigations. Clinical observations and laboratory tests (blood and cerebrospinal fluid cytology and biochemistry) revealed no ill-effects or deviations attributable to the immunization procedure. After administration of the immunizing dose, no viraemia was detected and specific seroconversions from negativity to positivity were found after 9 weeks in 73-82% of the subjects, using different tick-borne encephalitis (western subtype) viruses in the virus neutralization experiments. The results obtained seem to give increased confidence in the further use of this attenuated virus clone with strictly defined characteristics.

Adult↗
PubMed1975

A live vaccine against tick-borne encephalitis: integrated studies. I. Basic properties and behaviour of the E5 "14" Clone (Langat virus).

The course of plaque segregation from the Langat E5 strain of the E5 "14" clone is described. The virus, displaying an ic+ sc s plus or minus t e u s character, reproduced at 35 and 37, but not at 39 degree C. In subcutaneously (sc) inoculated monkeys, viraemia lasted for 2--4 days without detectable central nervous system (CNS) involvement. In sc inoculated 8--10 g mice, the infection was manifested only by a transient trace viraemia, but caused a marked resistance against challenge with virulent tick-borne encephalitis (TE) viruses, protection indices being 5.7--6.7. Pathogenetic investigations in challenged, live virus-immunized mice showed no signs of a marked productive infection except of a booster effect.

Animals↗
PubMed1975

A live vaccine against tick-borne encephalitis; integrated studies, H. Histopathology of mice peripherally immunized with E5 "14" virus and challenged with virulent virus.

Histopathological changes in the central nervous and lymphoid systems were semiquantitatively analyzed in subadult mice (M) peripherally immunized with the live, highly attenuated E5 "14" virus from the tick-born encephalitis (TE) complex and in immunized M subjected to virulent challenge. The E5 "14" clone possesses an exceedingly restricted neuroinvasivity. A study of the sc marker, refined and extended by microscopic examinations seems to present a more relevant approach for comparative investigations on TE virus virulence. Morphological findings in immunized M given immunosuppressive doses of cyclophosphamide (CPA) suggest that the high efficiency of live vaccines may be related to the prolonged antigenic stimulation.

Animals↗
PubMed1975

A live vaccine against tick-born encephalitis: integrated studies. III. Response of man to a single dose of the E5 "14" clone (Langat virus).

The clinical and immunological events in volunteers following administration of 5 and 6 dex newborn mouse intracerebral LD5O (NmicLD5O) of the E5 "14" virus clone, segregated from the Langat TP21 E5 strain (tick-borne encephalitis-TE-complex) and propagated in 7 days old SPF chick embryos, are reported. The experimental vaccine, containing the cloned virus, carrying a set of genetic markers of an ic(+) sc s(+/-) t e u (s) N character, caused in volunteers no clinically recognizable effects, but elicited an immune response in them, as determined in PS-cell culture neutralization tests with various TE (western and eastern subtype) strains. In all vaccines, given the virus intramuscularly, seroconversions from negativity to positivity were observed, with antibody titres ranging from 4-128. The parenteral virus administration was superior to the oral route.

Administration, Oral↗
PubMed1973

Nonlinkage of neurovirulence exclusively to viral hemagglutinin or neuraminidase in genetic recombinants of A-NWS (HON1) influenza virus.

Genetic recombination of the neurovirulent A/NWS/cc-p (H0N1) and the non-neurovirulent A/Jap.305/57 (H2N2) influenza viruses in which hemagglutinin and neuraminidase were segregated (H0N2, H2N1) were studied for neurovirulence in mice immunosuppressed with cyclophosphamide (CPA) which permitted full expression of virulence. Both H0N2 and H2N1 recombinants replicated in the brain (in contrast to the H2N2 parent) and both produced lethal effects in CPA-treated animals. Therefore we conclude that A/NWS (H0N1) neurovirulence is not exclusively linked with either the hemagglutinin or the neuraminidase of the virus. The H0N2 and H2N1 recombinants have revealed the existence of two separate attributes of neurovirulence: (i) the capacity of virus to initiate intracerebral infection and (ii) the capacity of infection, once initiated, to produce lethal disease. These studies provide further evidence for the polygenic nature of A/NWS neurovirulence.

Animals↗