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Biomedical subjects

A Vasků

Publications and source records attributed to A Vasků.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Polymorphism of angiotensin converting enzyme (ACE) and TNF-beta genes in men with disorders of spermatogenesis--pilot study].

INTRODUCTION: The presence of components of the renin angiotensin system and tumour necrosis factor in a male reproductive tract supports the hypothesis that these substances may influence reproductive functions. It was proved that angiotensin II as a product of ACE has influence on sperm capacitation and motility. TNF-beta is released from T-lymphocytes and has the regulatory effect on steroidogenesis and spermatogenesis. Aberrations of these agents can result in infertility. OBJECTIVE: The aim of this study was to determine the allele frequency of ACE and TNF-beta genes in men with pathological sperm count and men with normal fertility. We examined the insertion/deletion (I/D) ACE and B1/B2 TNF-beta gene polymorphic alleles and analyzed their frequency in patients and fertile men. DESIGN: A pilot study. SETTING: 1st Clinic of Gynaecology and Obstetrics and Institute of Pathologic Physiology, Masaryk University, Brno, CR. MATERIAL AND METHODS: The genomic DNA was isolated from peripheral blood leukocytes by a standard method according to Sambrook in a group of 46 patients (33.4 +/- 7.2 years) with pathological sperm count (9 azoospermia, 21 severe oligoasthenospermia, 16 moderate oligoasthenospermia) and in a control group of 88 healthy men (31.2 +/- 9.3 years) with normal fertility. Polymerase chain reaction (PCR) was used for genom analysis. The method according to Rigat was used for the I/D ACE polymorphism. B1/B2 TNF-beta genotype of each patient was determined after Nco I digestion of the amplified product and subsequent agrose gel electrophoresis. Fisher's exact test and chi square test were used for statistical analysis. RESULTS: In the study we found these differences of allel frequency and their combination: 1. Combinations of the genotype II (ACE) + B1B2 (TNF-beta) and genotype II (ACE) + B2B2 (TNF-beta) were less frequent in patients (8.7%) than in fertile men (28.4%), this difference was statistically significant (p = 0.021). 2. Allele B1 (TNF-beta) was more frequent among patients (40.2%) than in the control group (29.5%), this difference was near to the point of statistical significance (p = 0.05). 3. Allele D (ACE) frequency was higher in men with pathological sperm count (52.2%) than in fertile men (44.9%), this difference was not statistically significant (p = 0.15). CONCLUSION: The study has found different allele frequency of I/D ACE and B1/B2 TNF-beta genes polymorphism in men with pathological sperm count compared to men with normal fertility. These results could contribute to elucidate the genetic background of a male infertility.

Adult↗
PubMed2001

Variants of endothelin-1 gene in atopic diseases.

BACKGROUND: Several studies suggest that the vasoactive peptide endothelin-1 (ET-1) could be involved in the pathophysiology of atopic asthma and allergic rhinitis. However, a possible involvement of polymorphisms of the corresponding gene in the origin of these conditions has so far not been subjected to a more comprehensive study. OBJECTIVE: This study investigates a possible association of two common polymorphisms in the ET-1 gene (TaqI in intron4 and BsiYI in position 138) with clinically manifested atopic diseases. The genetic linkage of these polymorphisms with the underlying phenotypes of asthma or parameters of atopy including total IgE level was examined, too. METHODS: The study included 456 subjects-270 Czech patients (Caucasians, Central Europe) with clinically manifested atopic diseases and 186 unrelated referent subjects with negative familial history of asthma/atopy. ET-1 genotypes were determined by PCR and restriction analysis by TaqI and BsiYI, respectively. RESULTS: No significant differences were found for the two polymorphisms between atopic patients and healthy subjects, or between subselected asthmatic patients and controls. However, the insertion exonic variant of ET-1 gene showed a significant association with signs of atopy, especially with total serum IgE levels (total IgE levels < or = 150 IU/ml turned out to be associated with DD genotypes, total IgE > 150 IU/ml with II and ID genotypes [OR = 3.76 (95% CI: 1.52-9.34), p = 0.003, Pc = 0.0061). CONCLUSIONS: These findings suggest that ET-1 may participate in the pathogenesis of high total serum IgE level in clinically manifested atopic diseases in our population.

Adult↗
PubMed2000

Ultrafast detection of microsatellite repeat polymorphism in endothelin 1 gene by electrophoresis in short capillaries.

The methodology and instrumentation for fast denaturing electrophoresis in short capillaries was developed and exemplified by detection of short tandem repeat polymorphism in the endothelin 1 gene. The resolution of two nucleotides, which is required for the detection of a dinucleotide repeat polymorphism, was achieved in a capillary of an effective length of 2.5 cm at a temperature of 600C and an electric field strength of 600 V/cm in 42 s. Thus, the use of denaturing electrophoresis in short capillaries with laser-induced fluorescence detection resulted in a reduction of analysis time by a factor of 200 when compared to the conventional slab gel electrophoresis. The developed methodology and instrumentation is advantageous for an implementation in clinical diagnostics and genetic population screening where fast analytical instrumentation amenable to automation is of paramount importance.

DNA↗
PubMed2000

Single effects of apolipoprotein B, (a), and E polymorphisms and interaction between plasminogen activator inhibitor-1 and apolipoprotein(a) genotypes and the risk of coronary artery disease in Czech male caucasians.

To evaluate whether polymorphisms in genes whose products are involved in lipid metabolism and fibrinolysis alter the risk of coronary artery disease (CAD), allele frequencies of four genetic polymorphisms were ascertained by PCR-based methods in 175 Czech male patients with coronary artery disease and in 222 Czech men with no symptoms of CAD. The following polymorphisms were studied: apolipoprotein B (apo B) signal peptide insertion/deletion polymorphism, 5' apolipoprotein(a) [apo(a)] TTTTA repeat polymorphism, apolipoprotein E (apo E) varepsilon2, varepsilon3, varepsilon4 polymorphism, and plasminogen activator inhibitor-1 (PAI-1) 4G/5G promoter polymorphism. Apo B and apo(a) allele frequencies differed significantly between the CAD and the control groups (P<0.01 each), with higher frequencies of apo B deletion and apo(a) shorter repeat alleles in the CAD group. We did not observe any differences in allele frequencies of either PAI-1 or apo E polymorphisms but the genotype frequencies of apo E were slightly different between the two groups (P<0.05). In addition, we observed a gene-gene interaction between the PAI-1 and apo(a) polymorphisms with respect to the risk of CAD. None of the polymorphisms studied were associated with the severity of CAD or a history of myocardial infarction. Our findings support the idea that several polymorphisms in apolipoprotein genes may by themselves and/or in interaction with other polymorphisms contribute to risk factors for CAD in men.

Adult↗
PubMed2000

Polymorphisms in inflammation genes (angiotensinogen, TAP1 and TNF-beta) in psoriasis.

This study focused on the association between plaque psoriasis and polymorphisms of several inflammation genes. Included in the study were 142 Caucasian (Czech) patients with plaque psoriasis and 141 healthy subjects. The genotypes of the polymorphisms in angiotensinogen [M235T ATG, A(-6)G ATG], in transporters associated with antigen processing TAP1 (TAP1*0101, TAP*02011 and TAP1*0301) and in lymphotoxin alpha (TNFbeta) (NcoI in intron 1) were detected by polymerase chain reaction-based methods and restriction enzyme analysis. An increase in B1 (less frequent) allele of NcoI TNFbeta polymorphism was found in psoriatic patients compared to healthy individuals (odds ratio = 1.6, 95% confidence interval 1.13-2.26, P = 0.006). A positive family history of psoriasis was associated with a higher B1 allele frequency in NcoI TNFbeta (P = 0.011). Hardy-Weinberg disequilibrium was found in TAP1 polymorphism A-->G at nucleotide 1207 in psoriatic patients. A case-control difference was found in the allelic concurrence of M235T and A(-6)G ATG polymorphisms. The most frequent population genotypes MMGG, MTAG and TTAA were observed in 92% of patients vs 74% of control subjects (odds ratio 0.29, 95% confidence interval 0.14-0.60, P = 0.0003). A positive history of tonsillitis and/or tonsillectomy was associated with a higher T allele frequency of the M235T ATG polymorphism (P = 0.037) as well as with a higher G allele frequency of the A(-6)G ATG polymorphism (P = 0.022). Polymorphisms in proinflammatory angiotensinogen and TNFbeta genes were associated with plaque psoriasis, a positive family history of psoriasis and with frequent tonsillitis in childhood.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Association analysis of 24-h blood pressure records with I/D ACE gene polymorphism and ABO blood group system.

The purpose of this study was to analyze the association between 24-h blood pressure parameters, insertion/deletion polymorphism of the angiotensin I converting enzyme gene and the ABO blood group system in a sample of the general Czech population. Fourteen parameters describing the 24-h blood pressure readings were obtained by analyzing blood pressure records in 243 volunteers, 119 men and 124 women. These parameters were adjusted for sex and body mass index (BMI) by means of multiple regression test. All subjects were genotyped for the insertion/deletion polymorphism of angiotensin I converting enzyme (I/D ACE) gene and routinely examined for the blood group phenotype in the ABO system. An association was found between the interaction of I/D ACE gene polymorphism and ABO blood group system on the one hand and mean values of systolic (p=0.016) or mean arterial (p=0.027) blood pressures and the phase shift of 24-h BP rhythm (p=0.036) on the other hand. Among three I/D ACE variants the DD genotype was associated with the highest values of mean blood pressure in blood group A and AB carriers. The same genotype was associated with the lowest blood pressures in blood group B and O carriers. In subjects with the DD genotype, the earlier daily position of the maximum of 24-h BP rhythm was found in blood group B, AB and O carriers. On the contrary, blood group A was associated with the latest position of maximum of the 24-h BP rhythm in the DD genotypes.

ABO Blood-Group System↗
PubMed1998

Angiotensin I-converting enzyme and angiotensinogen gene interaction and prediction of essential hypertension.

To prove whether the interaction between insertion/deletion (I/D) angiotensin I converting enzyme (ACE) and M235T angiotensinogen (AGT) gene polymorphic alleles could contribute to causing essential hypertension, we examined subjects from the Czech Republic (365 Caucasians total; 202 normotensives and 163 hypertensives). Subjects were genotyped for insertion/deletion polymorphism of ACE (I/D ACE, intron 16) and for M235T polymorphism of angiotensinogen gene (AGT, exon 2) by means of the polymerase chain reaction (PCR) method. The case-control approach was used. Fisher's exact test followed by Holmes's test to overcome the problem of multiple comparisons were used for the statistical analysis of data. No association of single gene allelic variants with essential hypertension was found in our population. Having compared only double homozygote combinations, the association of the DDMM genotype with essential hypertension was proven (P = 0.0081). To the contrary, IITT (P = 0.0086) was found more frequently in normotensive subjects. We conclude that the interaction of the I/D ACE and M235T AGT polymorphic alleles can contribute to essential hypertension, despite the absence of single gene associations with the condition.

Adult↗
PubMed1998

Lung diffusion estimated by oxygen and carbon monoxide.

The study was objected to the comparison of the results of lung diffusion estimated by oxygen to those of routinely used single breath carbon monoxide method. The method described is based on the analysis of the speed of response of arterial partial oxygen pressure (paO2) to increasing inspiratory fraction of oxygen (Fi). The transcutaneous oximetry was used to follow paO2 by means of transcutaneous oxygen pressure (ptCO2). The study was performed on 35 patients of both sexes with interstitial lung involvement with normal or only slightly decreased FVC and FEV1. The close correlation between the results of both methods was proved (r = 0.848, p < 0.0001).

Adult↗
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↗
PubMed1989

[Therapy of venous hypertension in animals with an artificial heart and long-term survival].

1. The authors elaborated an original concept for the interpretation of vasomotor disorders in subjects with an artificial heart. 2. This concept is based on the regeneration of nervous elements in the walls of the atria (in particular the right one) after implantation of the artificial heart and on comparison of their activity with the venous pressure which revealed the interrelationship of the two phenomena. 3. Both therapeutic methods based on this concept, the method of influencing the afferentation and efferentation of vasomotor nervous regulations leading to a reduction of the central venous pressure proved valid and effective. 4. Evaluation of the effectiveness of this therapy is based on regular assessment of the central venous pressure, on the laboratory assay of enzymes (AST, ALT, GMT and LDH), on the assessment of serum albumin and finally on the morphological and histological examination of the liver incl. assessment of the hepatic index. 5. The nervous pathogenesis is closely linked with hormonal factors. The latter are conceived as the participation of associated factors in the pathogenesis of venous hypertension in recipients with an artificial heart.

Animals↗
PubMed1989

Therapy of venous hypertension in calves with total artificial heart (TAH).

Vasomotor disregulation, preponderantly expressed by a pathological increase of central venous pressure (CVP) in calves with total artificial heart (TAH), starts to be evident from about the 50th day of pumping. The main cause of this state is an imbalance in cardiac receptor areas. Ventricular vasodepressor mechanisms are eliminated with the ventricular tissue, which is replaced by the artificial blood pump. In the stumps of both atria, which remain in situ, all neural elements disappear immediately after TAH implantation, but within two months they are fully regenerated. Regenerated atrial receptors are the starting points of afferent neural stimuli, which in the vasomotor center of the brainstem, increase the activity of the vasoconstricting functional component. A general tendency to vasoconstriction, now not well counterbalanced, increases, and the progressive venous hypertension causes loss of liver function and morphology. Two therapeutic approaches were tried: afferent therapy by atrial electrical stimulation, and efferent therapy by the administration of antihypertensives. Both kinds of this therapy were sufficiently effective in reducing CVP, protecting the liver, and prolonging average survival.

Animals↗
PubMed1988

Serum aldosterone studies in 10 calves living for 2-5 months with a total artificial heart (TAH).

A group of 10 experimental calves that lived for 61-147 days with a TAH was used to study serum aldosterone levels by RIA with ALDOCTK-125 CEA Kit (Sorin Biomedica, Italy). The aldosterone levels were plotted against the serum sodium and potassium, body weight, CVP, urinary sodium and potassium and with hematocrit levels. In these experiments, three types of TAH (TNS-BRNO II, VII, and Rostock) were used. The levels of aldosterone were already high before the surgery and during the entire pumping period, which indicates the development of secondary aldosteronism. The study deals with the mechanisms that participate in the development of aldosteronism in each phase of the experiment with the TAH.

Aldosterone↗
PubMed1987

Haemocompatibility of segmented polyurethanes investigated in vivo.

Samples of segmented polyurethanes differing in composition and in surface morphology were introduced into the left ventricles of hearts of goats for 72 h. After removal of the samples, their surface and the surface of the heart endothelium were evaluated visually with respect to the formation of thrombi. Differences in the interaction of the individual polyurethanes with blood were examined by XPS photoelectron spectroscopy, SEM, and by infrared (i.r.) reflexion spectroscopy. The results suggest ways for improving the haemocompatibility of the surfaces of polyurethanes used as parts of the total artificial heart.

Animals↗