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Biomedical subjects

A Ivan

Publications and source records attributed to A Ivan.

At least 19 recordsLinked to original sources
PubMed1998

Mathematical analysis of reactive hyperaemia in the isolated rat heart with & without electrical pacing.

Studies were undertaken for a mathematical analysis of reactive hyperaemia in the isolated rat heart with and without electrical pacing and the introduction of a new parameter i.e., rate of reactive hyperaemia, to evaluate reactive hyperaemia. Rate of reactive hyperaemia is represented as a change of coronary perfusion pressure in function with duration of reactive hyperaemia (delta P/DRH). The experiments were performed on the isolated rat heart using constant flow Langendorff's technique. Reactive hyperaemia was induced by interruption of coronary inflow for 30, 60, 120 sec. The electrical pacing produced two-phasic changes in the coronary perfusion pressure (CPP). Restoration of CPP (a long lasting gradual increase of coronary perfusion pressure after the period of ischaemia) correlated well with time following the logistic function. Correlation coefficient was 0.9485 (P < 0.05) with electrical pacing and 0.9892 (P < 0.05) for CPP restoration without electrical pacing. Duration of reactive hyperaemia was significantly (P < 0.05) shorter with electrical pacing than without it. However, the rate of reactive hyperaemia was not significantly different with or without electrical pacing. Fitting of the experimental results as well as the rate of reactive hyperaemia suggest the same mechanism of CPP restoration during the reactive hyperaemia with or without pacing. However, the extent of the phenomenon is significantly affected by pacing.

Animals↗
PubMed1983

Our experience in viral hepatitis (VH) immunoglobulin prophylaxis.

Two experiments on 72 888 children, out of which 36 270 received standard immunoglobulins (IG) and another 36 618 represented the control group, were carried out. IG was administered preventatively, during autumn before the occurrence of the annual peak, and in focus after contact with VH patients. Prophylactic IG administration led to a 4-14 fold decrease in the incidence of icteric VH as compared with controls, and to the disappearance of the peak characteristic of autumn-winter. The efficacy lasted for 5-6 months. The incidence of subclinical VH forms--as evaluated by clinical examinations and SGPT was about 3 times lower in IG pre-exposure recipients. In the group of children where IG was administered only to the contacts in epidemiological foci, the incidence of icteric VH remained as high in the controls and the incidence of subclinical VH forms was twice as high in the controls.

Child↗
PubMed1977

Excess mortality--influenza epidemiological surveillance indicator.

Observations on "excess mortality" from influenza, carried out in the Moldavia area between 1957 and 1973, are presented in the paper. They made it possible to assess in time and space as well as in severity the knowledge on influenza epidemics. "Excess mortality" proved to be a valuable indicator of increase in influenza mortality, especially, on the occurrence of big epidemics the existence of which was closely related to the appearance of new types and variants of influenza viruses. Though "excess mortality" showed the highest values when death from acute pneumopathies recorded in the preepidemic and postepidemic periods was included in the calculation, it also pointed to the strong effect of influenza on all causes of death, especially chronic diseases of the respiratory and cardio-vascular systems.

Disease Outbreaks↗
PubMed1975

Sources of hepatitis B virus infection in hospital environment.

Investigations on the incidence of hepatitis B antigen (HB Ag)-carriers among 1466 patients of 11 various hospitals and departments showed that sources of hepatitis infection were more numerous in hospitals for children than in those for adults. The high-risk departments were those of dialysis (5 out of 12 patients), clinical medicine (6.6%), and obstetrics and gynecology, for adults, and those of neuropsychiatry (17.9%) and clinical medicine (11.2%)for children . The highest incidence of HB Ag-carriers among the medico-sanitary personnel of 5 hospitals (436 sera) was recorded in a hospital of obstetrics and gynecology.

Carrier State↗