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Biomedical subjects

M Dostál

Publications and source records attributed to M Dostál.

At least 37 records · Page 2Linked to original sources
PubMed1994

Instrumentation of ramus circumflexus compromises the innervation of coronary artery and myocardium.

A fine non-compressing methacrylate ring was implanted on the ramus circumflexus (RC) in 13 dogs. After the animals survived 7-14 days, the distribution and the rate of the Wallerian degeneration was studied in coronary arteries and myocardium by means of the formaldehyde induced fluorescence (FIF) technique and the transmission electron microscopy. The density of vasomotor innervation in the main arterial trunks was expressed as the number of transsected terminals per 1 mm2 of the transversally sectioned media; the density of adrenergic terminals in the myocardium was determined by the point-counting method. A compact scar encompassing the ring was found. The scar compressed some perivascular nerves. As a consequence, by about 40% of terminals degenerated in the RC. The innervation of the branching of this artery was compromised as well. Moreover, the density of nerve terminals in myocardium decreased around the whole circumference of the ventricles and in the septum, equally by 29%. The value was lower than that found after the instrumentation of ramus interventricularis anterior (50%). The results indicate (i) a compromise of the innervation of coronary artery and myocardium after the instrumentation of RC; (ii) the different decrease in density of nerve terminals in the myocardium suggests that majority of adrenergic nerve supply for ventricle myocardium is running along ramus interventricularis anterior.

Animals↗
PubMed1994

Early postnatal diazepam treatment of rats and neuroimmunocompetence in adulthood and senescence.

Functional teratogenic risk of perinatal diazepam (D) treatment was studied in animal model experiments using early postnatal D administration in rats (single dose of 10 mg/kg sc in 7-day-old pups) and long-term follow-up till the age of 18 months with monitoring of behavior, reproductive functions, brain biochemical variables, and immune system reactivity. Behavioral tests carried out at the age of 6, 12, and 18 months indicated higher emotionality and deviations of novelty reaction in D rats in comparison with controls, and these differences decreased with aging. However, no deficits were found in memory testing. D rats revealed some transitional alterations of monoamine neurotransmission in the hypothalamus (5-HT) and striatum (DA) and minor defects in reproductive functions (irregular estrous cycles in females). Significant depression of immune response in D rats persisting for the whole life may be considered as a serious risk of neonatal D treatment.

Aging↗
PubMed1994

Treatment of pregnant mice with antibiotics modulates the humoral response of the offspring: role of prenatal and postnatal factors.

This study was designed to determine the role of prenatal and postnatal factors underlying altered humoral response of the offspring of mice treated with antibiotics during pregnancy. Pregnant random-bred NMRI mice were administered i.p. from the 11th to 15th day of pregnancy with a mixture of ampicillin and cloxacillin (2:1) in a daily dose of 21 mg/kg body weight. The litters of experimental and control mothers were cross-fostered at birth and the offspring were immunized on the 23rd or 24th postnatal day with SRBC. The primary humoral response was assayed using spectrophotometric determination of SRBC lysis mediated by anti-SRBC IgM antibodies produced by spleen cells. The offspring born of saline-treated mothers and transferred to mothers treated with antibiotics, as well as the offspring born to mothers treated with antibiotics and transferred to mothers treated with saline, produced significantly higher amounts of spleen anti-SRBC IgM than the control offspring. The results suggest that the immune response of the offspring was modulated by both the prenatally and postnatally acting factors, the latter being mediated by effects of antibiotics on the maternal organism.

Ampicillin↗
PubMed1994

Indirect maternal effects of oxacillin administered to pregnant mice on the postnatal immune response of the offspring.

Effects of oxacillin administered to pregnant or nursing randombred NMRI mice on the humoral immune response of their offspring were studied. The primary humoral response of male offspring to immunization by sheep red blood cells (SRBC) on the 24th postnatal day was assayed. Spectrophotometric determination of SRBC lysis by anti-SRBC IgM antibodies produced by spleen cells was used. Treatment of pregnant mice with oxacillin (70 mg/kg body weight) from the 12th to 16th day of pregnancy resulted in an enhancement of the spleen IgM antibody response in their offspring. The same treatment of nursing mothers, either on postnatal days 1-4 or 13-16, depressed the humoral response of the offspring. When the litters of control mothers and mothers treated with oxacillin from the 11th to 15th day of pregnancy were cross-fostered at birth, the offspring born of saline-treated mothers and nursed by oxacillin-treated mothers as well as the offspring born to oxacillin-treated mothers and nursed by control mothers produced significantly higher amounts of spleen anti-SRBC IgM than the control offspring. The results suggest that the alteration of the immune response in offspring of mice treated by oxacillin during pregnancy was induced not only in the prenatal period, but also postnatally by factors originating from effects of oxacillin on the maternal organism.

Animals↗
PubMed1993

Perinatal hypoxia suppresses immune response of adult rats.

We tested the effect of perinatal (one week prenatal and one week postnatal) normobaric hypoxia on the immune response of rats in their 9th week of life. We found that perinatally hypoxic rats produced less serum antibodies after sequential immunization with ovalbumin and sheep red blood cells. Also phagocytosis of HEMA microparticles by neutrophil leukocytes from perinatally hypoxic rats was depressed as well as the oxidative burst of their peritoneal macrophages and neutrophils. These results demonstrate that perinatal hypoxia has an important effect on the immune system of the rat.

Animals↗
PubMed1993

Perinatal hypoxia suppresses immune response of adult rats.

We tested the effect of perinatal (one week prenatal and one week postnatal) normobaric hypoxia on the immune response of rats in their 9th week of life. We found that perinatally hypoxic rats produced less serum antibodies after sequential immunization with ovalbumin and sheep red blood cells. Also phagocytosis of HEMA microparticles by neutrophil leukocytes from perinatally hypoxic rats was depressed as well as the oxidative burst of their peritoneal macrophages and neutrophils. These results demonstrate that perinatal hypoxia has an important effect on the immune system of the rat.

Animals↗
PubMed1992

Activity of glucose-6-phosphate-dehydrogenase enzyme studies in calves with long--survivals with total artificial heart.

The research aimed at studying metabolic changes of erythrocytes in the calves surviving for a long period with total artificial heart of BRNO VII type. The authors studied partly the count of erythrocytes, the plasma levels of free hemoglobin and activity of glucose-6-phosphate-dehydrogenase enzyme. The changes found were compared with the levels measured in a group of 10 healthy calves. Constant decrease of erythrocyte count, slightly increased concentration of free hemoglobin in plasma and repeatedly decreased activity of the enzyme studied were found in the group of 4 experimental calves, from the 5th to 17th weeks of surviving. These changes can be explained by a long-term action of mechanical stress on the erythrocytes that pass through the pump of the total artificial heart. The cells damaged mechanically have the decreased energetic metabolism and, consequently, shortened viability. As young healthy animals with normal erythropoiesis which is stimulated by the application of drugs during the experiment are used, compensated anaemia develops, but it is not a limiting factor for the surviving of the calves with total artificial heart.

Anemia, Hemolytic↗
PubMed1992

Abnormal delayed-type hypersensitivity in mice born to females treated with vitamin A during pregnancy.

The effects of vitamin A (retinolum palmiticum) administered to pregnant mice on the cell-mediated immunity of the offspring were studied in random-bred ICR mice. Delayed-type hypersensitivity (DTH) to sheep red blood cells was assayed after immunization of the control and experimental young in the 4th postnatal week. The administration of vitamin A, in doses of 5,000 IU, on days 15-17 of pregnancy depressed DTH of the female offspring. On the other hand, the administration of single doses of 5,000 and 10,000 IU on the 16th day of pregnancy increased DTH in the offspring. The effects were correlated to the sex and body weight of the offspring, the highest DTH being observed in the female offspring with a low body weight.

Animals↗
PubMed1992

Biochemical and immunological studies in calves living over three months with a total artificial heart.

Changes in serum proteins, enzymes and isoenzymes of lactate dehydrogenase (LDH) were compared in long-term surviving calves with a total artificial heart without influencing their central venous pressure (CVP) and calves in which CVP was lowered by antihypertensive drugs administered from day 60 to the end of the experiment. Antihypertensive drugs helped keep CVP within physiological levels for longer and aided liver function as well as evidenced by the different values for the parameters studied in the two groups.

Animals↗
PubMed1992

[Calve-Legg-Perthes disease].

The authors present in a review contemporary views on the pathogenesis, classification and diagnosis of Perthes disease. At the same time they indicate possible therapeutic interventions and discuss their justification. They emphasize the demand of close collaboration of the paediatrician and orthopaedic surgeon.

Child↗
PubMed1992

The applicability of experimental experience with the total artificial heart to its clinical use.

Long-term experiments with the total artificial heart (TAH) are a source of valuable knowledge for later clinical application. Our observations result from 66 long-term experiments on calves and one goat ranging from 30 to 314 days, which have shown the main possible complications in the early period (one month) and later in the experiment. Problems until the second month of pumping concern the clinical pendant of the TAH as a bridge for transplantation, i.e. surgical problems, blood coagulation disorders, infection etc. Later problems are high venous pressure or arterial hypertension, infection with septic thromboembolization, mineralization of the driving diaphragm, etc., and are more closely comparable to the conditions of permanent clinical use of the TAH. Faultless surgery, device function and the regimen of pumping are essential factors in every long-term experiment, just as in clinical application. Infection is a threat throughout any experiment, as in clinical cases. The TNS-BRNO-VII/clin/80 TAH has been implanted in six patients.

Adult↗
PubMed1991

Developmental toxicity of cadmium in mice. I. Embryotoxic effects.

Embryotoxic effects of CdCl2 administered in a single dose of 2.0, 4.0 or 6.0 mg/kg body weight to randombred ICR mice (Velaz) on the 8th, 9th, 10th, 11th, 12th, 13th or 14th day of pregnancy were studied. The embryolethal effect, being highest after treatment with 6.0 mg/kg CdCl2 on the 12th and 13th day of pregnancy (50.0 and 61.3%) was not significantly correlated to the day of treatment. Among survivors, foetuses with haemorrhagic bullae, limb malformations, exencephaly, cleft palate, open eyelids and tail deformities occurred. Mainly the right-sided limbs were malformed. The administration of 2.0 and 4.0 mg/kg CdCl2 on the 10th day of pregnancy induced fore limb polydactylies, whereas with the dose of 6.0 mg also oligodactylies were induced. The foetal body weight was reduced only by a dose of 6.0 mg CdCl2 administered on the 12th day of pregnancy. Reduction of the thymus weight was a constant effect of treatment with the higher doses of cadmium from the 9th to the 14th day of pregnancy.

Abnormalities, Drug-Induced↗
PubMed1991

Effects of antibiotics on the developing immune system.

A combination of penicillin and cloxacillin (Ampiclox, Beecham Research Laboratories) is indicated for prophylaxis and treatment of bacterial infections in premature babies or neonates. We studied the functional development of the immune system in the offspring of female ICR mice administered Ampiclox on days 13-16 of pregnancy in clinically relevant doses. Immune functions were assayed after immunization with sheep red blood cells in the 5th and 10th postnatal week. Changes of hemagglutinin antibodies, delayed-type hypersensitivity and proliferative responses of spleen lymphocytes and thymocytes were observed. Ampiclox influenced humoral immunity also when administered directly to rat young on postnatal days 9-11 or 14-16. Although the clinical relevance of our experimental data remains to be established an increased sensitivity of the developing immune system to immunomodulatory effects should be considered also in the context of antimicrobial therapy. (Fig. 6, Ref. 27.)

Ampicillin↗
PubMed1991

Developmental toxicity of cadmium in mice. II. Immunotoxic effects.

Pregnant randombred ICR mice were administered 2.5 or 5.0 mg/kg body weight of CdCl2 on day 16 of pregnancy and immune responses of their offspring were tested postnatally. At the age of 4 weeks, proliferative responses of spleen cells to concanavalin A, phytohemagglutinin and lipopolysaccharide and the background proliferation were enhanced in both experimental groups. The activation index was increased only after activation with concanavalin A and lipopolysaccharide in the group treated by the dose 5 mg/kg. The delayed type hypersensitivity to sheep red blood cells after immunization at 4 weeks was decreased. The serum IgM antibody response to sheep red blood cells was increased in the offspring of females treated with the lower dose of cadmium both at week 4 and 8. Activity of peritoneal macrophages (NBT, H2O2) was enhanced at 4 weeks and lowered subsequently. It is concluded that in mice the maternal exposure to a single dose of cadmium results in postnatally manifested deviations of immune functions of their offsprings.

Animals↗
PubMed1990

Mineralization of polyurethane membranes in the total artificial heart (TAH): a retrospective study from long-term animal experiments.

The degree of mineralization of TAH membranes in animals is directly related to the survival time of animals with a TAH. Large differences in mineralization of the membranes among individual animals have been observed. These differences can be explained by the simultaneous presence of infection on biomaterials (polyurethane) as well as by different levels of natural inhibitors of mineralization. No positive influence of applying sodium warfarin for the inhibition of the mineralization was observed.

Animals↗
PubMed1990

Evaluation study of calves with total artificial heart (TAH) surviving for 218-293 days of pumping.

Evaluation of five longest surviving calves among a total of 54 longterm survivors, at the Brno Research Centre was performed. These calves were treated by administration of antihypertensives and partially by electrical stimulation of the right atrium to reduce central venous pressure (CVP). Treatment for CVP was effective, as compared with two groups of 5 calves each not treated in this way, and it is assumed to be an important factor for prolongation of survival. Mineralization of driving diaphragms was present in all these calves. No preventive measures of this pathologic change were performed in this group. Another complication is hemolysis, which is partly caused by immune mechanisms initiated by administration of alpha-methyl dopa and partly by mechanical destruction due to a heavily mineralized driving diaphragm. The prevention of mineralization is another important problem for future research. Other problems, concerning the survival of TAH recipients are discussed.

Animals↗