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Biomedical subjects

A Lukaszyk

Publications and source records attributed to A Lukaszyk.

At least 19 recordsLinked to original sources

Quantitative mRNA analysis of IL-1 gene system in human testis.

PROBLEM: There is a growing body of evidence that interleukins exhibit modulatory activity on development of reproductive cells. In this context, there appears to be a role for IL-1, which is also produced in human testis. We have analysed transcripts of IL-1 gene system (IL-1alpha, IL-1beta, IL-1RI, IL-1RII and IL-1RA) to evaluate the possible link between the level of gene(s) transcription and their function. METHOD OF STUDY: To determine the activity of gene transcription, a quantitative PCR with isotopic and/or nonisotopic detection was applied. RESULTS AND CONCLUSIONS: We have detected differential expression of IL-1alpha and IL-1beta genes in separate functional compartments of a male gonad. A strong expression of IL-1alpha gene in an intratubular cell fraction was shown, while the IL-1beta expression seemed to be dominant in extratubular compartment of the male gonad. Abundant amounts of IL-1RA mRNA in gametogenic cells fraction slightly higher than in interstitium have also been found. IL-1RA is the most important regulatory molecule in IL-1 system, which down-regulates activity of both interleukins. Looking more closely at gene(s) differential expression it appears that IL-1alpha can be preferentially down-regulated by IL-1RA gene in intratubular fraction while the IL-1beta, through the "false" IL-1RII receptor in the interstitium. Genes coding for both receptors (IL-1RI and IL-1RII) showed, however, relatively low levels of transcription in both studied compartments. IL-1 genes system creates a complex intragonadal environment and the function of these genes is reflected by their respective distribution in the two main functional compartments of the testis.

Base Sequence↗

The influence of interleukin-1 and interleukin-6 on expression of proteins involved in steroidogenesis in Leydig cells and on their apoptosis or necrosis in vitro.

This paper presents a study on the expression of proteins involved in steroidogenesis in rat Leydig cells: StAR protein and aromatase, in relation to the age of animals and to the influence of interleukin-1 and interleukin-6. In addition, their effect on apoptosis and damage of Leydig cells was investigated. Leydig cells were isolated from rats at certain age intervals and exposed to different concentrations of the above-mentioned cytokines. Next, total RNA was isolated from Leydig cells and RT-PCR with primers specific for rat StAR protein and aromatase was performed. The products were analysed by agarose gel electrophoresis. Leydig cells were also stained with propidium iodide and Hoechst 33342 to estimate the percentage of apoptotic or necrotic cells. The results seem to confirm the role of interleukins in the control of expression of enzymes and regulatory factors involved in steroidogenesis in rat Leydig cells, and in the regulation of their apoptosis and necrosis. The effect of the studied interleukins on Leydig cells is exerted during development and after adolescence.

Animals↗

An example of application of molecular techniques to the study on the local regulatory system controlling the function of the rat male gonad.

Molecular biology techniques help to study details of testicular cell interactions, which play an important role in the control of spermatogenesis and secretory function of the male gonad. This paper presents an example of application of such techniques, with evaluation of their usability, in the study on expression of some cytokines involved in cellular interactions in the rat testis. Testicular cells were isolated by digestion with collagenase followed by percoll gradient centrifugation or by the adherence technique (macrophages). Then RNA was isolated from cells using Chomczynski-Sacchi method and analysed by electrophoresis and spectrophotometry. RNA was reversely transcribed using oligo-dT15 primer and AMV (Avian Myeloblastosis Virus) transcriptase. cDNA was amplified by PCR with primers for rat IL-1alpha, IL-1beta, IL-6 and Tbr (Thermus brockianus) polymerase. RT-PCR products were analysed by electrophoresis. Chomczynski-Sacchi method proved to be effective for isolation of good quality RNA even from small number of cells. RT-PCR revealed the presence of mRNA for studied cytokines in isolated cell. The results indicate that the applied techniques are useful in studies on the function of male gonad and indicate the need for use of semi-quantitative methods for evaluation of cytokine expression.

Animals↗

Immunocytochemical observations on the organ distribution of exogenous monomeric and dimerized lysozyme.

Using commercial anti-lysozyme antibodies and anti-dimerized lysozyme rabbit serum produced by us we demonstrated by immunohistochemistry, in some organs of rats, the expression of exogenous egg white lysozyme preparations beside the native lysozyme. After oral administration, the egg white lysozyme was detected in intestinal epithelium, proximal and distal tubules of some nephrons, pulmonary alveolar walls and hepatocytes in the 3rd zone of liver acini, whereas native lysozyme was strongly expressed in intestinal and pulmonary macrophages in both the experimental and control animals. However, expression of the dimerized lysozyme released from the intraperitoneally implanted mini-osmotic pumps and detected using specific antisera was evident only on erythrocytes in intestinal blood vessels. It is concluded that the lysozyme preparations administered per os or parenterally are resorbed to blood circulation and distributed among various organs in an active form and maintaining their antigenic specificity. It may speak for their direct anti-inflammatory and immunomodulatory effects in respiratory, urinary, digestive and other systems.

Animals↗

Ketanserin, an antagonist of 5-HT2A receptor of serotonin, inhibits testosterone secretion by rat Leydig cells in vitro.

The effect of ketanserin, an antagonist of 5-HT2A receptor of serotonin, added to the culture medium, on basal and LH-stimulated testosterone secretion was studied in primary cultures of adolescent rat Leydig cells. Ketanserin decreased the basal secretion of testosterone but showed an insignificant influence on the LH-stimulated process. It can be concluded that ketanserin may affect the testosterone-secreting cells by an indirect action at the vascular level as well as directly at the level of Leydig cells, at least in adolescent rats, leading to down-regulation of the basal testosterone secretion.

Animals↗

The role of epidermal growth factor in platelet-endothelium interactions.

The objective of this study was to determine whether endogenous EFG released after submaximal physical exercise, affects platelet-endothelium interactions. Sixteen healthy male volunteers, aged 23-26 years, were submitted to a submaximal bicycle ergometry test. Blood for determination of EGF concentrations, platelet function studies (concentrations of beta-TG, PF4 and TXB2) and endothelium activity (LTC4 and endothelin-1,2 concentrations) was taken via an intravenous catheter before starting exercise and 15, 30 and 60 min after. A similar scheme was followed to investigate changes in the same parameters induced by a slow intravenous infusion of 0.3 mg/kg b.w. phentolamine (an alpha-adrenergic blocker) before exercise. Plasma concentrations of EGF and the markers of platelet function-beta-TG and PF4 as well as LTC4 concentrations increased only 15 min following exercise. The concentrations of TXB2, and endothelium-1,2 were almost unchanged 15 min after the submaximal bicycle ergometry test. Phentolamine markedly decreased the EGF concentrations in plasma (15 min following exercise) while at 30 and 60 min after exercise it had no effect on this parameter. No significant changes in concentrations of beta-TG, PF6, LTC4 and endothelin-1,2 after phentolamine infusion were found. These results show that increase of plasma EGF following exercise was accompanied with increase of beta-TG, PF4 and LTC4 concentrations. Inhibition of alpha-adrenergic receptors with phentolamine abolished the exercise-induced increase in plasma EGF concentration. The findings suggest that endogenous EGF may affect the platelet function and changes the reactivity of the vascular endothelium.

Adult↗

Molecular evaluation of enteroviruses in the pathogenesis of idiopathic dilated cardiomyopathy.

BACKGROUND: There is great disparity in the literature as to the presence and relevance of enterovirus in heart tissue from patients with dilated cardiomyopathy (DCM). Published estimates of enteroviral positive tissue in DCM range from 0 to 50%. Very little sequence information is so far available on those samples which are positive. HYPOTHESIS: Re-examination of fresh biopsy material from patients previously tested, plus 13 new cases of DCM, and sequencing the products would yield information on the validity of the technique and on the type of virus being detected. METHODS: RNA from biopsy or explant tissue was tested for the presence of enterovirus using reverse transcriptase polymerase chain reaction (PCR). The nucleotide sequences of all positive PCR products were determined by direct sequencing. RESULTS: Positive PCR signals were found in 10% of samples from patients with DCM and in 16% of control tissues. Two DCM and 12 control samples gave the same nucleotide sequence, which was different from the CB3 used as a positive control. The other 4 DCM samples all produced multiple bands on sequencing. CONCLUSION: The results do not support a major role for enterovirus in DCM. There is need for some caution, however, as a review of the literature shows that studies using single biopsies, such as this one, produce consistently lower estimates for enterovirus than do those wherein multiple biopsies are examined.

Adolescent↗

Endogenous nitric oxide in the control of esophageal motility in humans.

Recent animal studies have suggested that nitric oxide (NO) plays an important role in the regulation of esophageal motility, being partly responsible for latency period and latency gradient between the onset of a swallow and contractions of esophageal circular smooth muscles. The aim of this study was to evaluate whether endogenous NO is responsible for physiological timing of forthcoming contractions in the human esophageal body after swallowing. Eight male volunteers (age 21-25 years, weight 67-82 kg) were involved in this placebo controlled study on the effects of increasing doses of the NO synthase blocker, NG-monomethyl-L-arginine (L-NMMA 1.0-4.0 mumol/min i.v.), and/or L-arginine (L-arg) (30 mumol/kg-min i.v.) on the peristalsis of esophageal body in response to wet swallows (5 ml of water) and lower esophageal sphincter (LES) resting pressure. The esophageal motor activity was determined manometrically using 3-channel electronic catheter. Additionally, during all examinations arterial blood pressure (BP) was measured every 5 min. L-NMMA resulted in a significant and dose-dependent reduction in the latency period between swallows and the onset of contractions which was most pronounced in the distal esophagus (control: 7.07 +/- 0.74 s vs. L-NMMA 4.0 mumol/min: 5.87 +/- 0.57 s), and this effect was partially reversed after addition of L-arg to the L-NMMA infusion (6.91 +/- 0.62 s). L-NMMA infusion significantly reduced the duration of contractions and increased the velocity of onset propagation but did not change the amplitude of contractions and again, these effects were reversed during simultaneous infusion of L-arg. The resting tone of LES increased significantly during infusion of L-NMMA and these effects were reversed by addition of L-arg. The mean BP significantly increased during infusion of L-NMMA (control 97.0 +/- 5.7 vs. L-NMMA 4.0 mumol/min: 116.4 +/- 3.1 mm Hg) and this was also reversed by L-arg. We conclude that in humans endogenous NO is involved, at least in part, in the physiological regulation of motility patterns of the distal esophageal body and LES.

Adult↗

Analysis of mRNA expression for interleukin-1 genes on human testicular cells.

We have investigated mRNA expression for IL-1 alpha and IL-1 beta gene on fractionated human testicular cells. Using RT-PCR and Northern blot hybridization technique we detected the presence of IL-1 alpha transcripts, predominantly in the intratubular compartment of the testis, comprising gametogenic and Sertoli cells. We were also able to detect mRNA for IL-1 alpha on the testicular interstitium, but at significantly lower levels. The intertubular compartment of the testis, mainly consisting of macrophages and Leydig cells, appeared however, to be a site for IL-1 beta gene expression. Our experimental data confirm previous results obtained in animal models indicating that the testis is capable of producing interleukin-1 under physiological conditions. Testicular IL-1 may function as a tissue-specific factor modulating both spermato- and steroidogenic activity of human testis.

Base Sequence↗

A prospective case-control study of antibodies to coxsackie B virus in idiopathic dilated cardiomyopathy.

OBJECTIVES: This study was conducted to determine the frequency and significance of Coxsackie B virus-specific immunoglobulin-M (IgM) in patients with idiopathic dilated cardiomyopathy and compare them with the frequency in both unmatched and matched control subjects. BACKGROUND: The principal evidence supporting a pathoetiologic role for Coxsackie B viruses in human dilated cardiomyopathy is derived from retrospective serologic studies. These studies have evaluated patients with end-stage disease and have failed to recognize the importance of assessing both matched and unmatched control subjects. METHODS: In this prospective case-control study, we assessed sera for Coxsackie B virus-specific IgM (serotypes B1 to B5) from 114 patients with dilated cardiomyopathy at diagnosis or referral to our center, 94 healthy unmatched control subjects, 41 healthy matched control subjects from the same general practitioner and 32 members of the patients' own households. RESULTS: A higher frequency of positive Coxsackie B virus IgM was observed in patients with dilated cardiomyopathy than in unmatched control subjects (33% vs. 5%; p = 3 x 10(-7)). In patients with dilated cardiomyopathy, the response was monotypic (84%), commonly against serotypes B2 and B5, and was not associated with any clinical or histologic feature. The frequency of positive virus-specific IgM was similar in patients with dilated cardiomyopathy and their 41 matched community control subjects (46% vs. 27%; p = 0.11) and 32 household contacts (37% vs. 28%; p = 0.59). Control subjects who tested positive for virus-specific IgM tended more commonly to be seropositive than did control seronegative subjects (community control subjects 37% vs. 18%, p = 0.32; household contacts 42% vs. 20%; p = 0.36) and had an identical serotypic response in 4 (33%) of 12 cases. CONCLUSIONS: The frequency of Coxsackie B virus IgM was higher in patients with dilated cardiomyopathy than in unmatched control subjects but was similar in patients and control subjects who shared the same environment, indicating local spread of infection. The reason for the association between Coxsackie B virus IgM and dilated cardiomyopathy and its relevance to pathogenesis remain to be established.

Adult↗

Analysis of mRNA for class I HLA on human gametogenic cells.

We have studied mRNA expression for Class I HLA (human leukocyte antigen) on male germ cells by amplification of gene fragments in PCR technique and by Northern hybridization. RNA was extracted from fractionated gametogenic cells (isolated from testis) and reversely transcribed. Then, cDNA was amplified for specific HLA sequence (HLA, -A, -B, -C). The specificity of this product was confirmed in "nested" PCR of 400 bp gene fragment coding for alpha 2 domain, alpha 3 domain, and the transmembrane portion of Class I HLA. The results indicate minimal expression of classical Class I HLA on gametogenic cells. Northern hybridization with 669 bp cDNA fragment (spanning for alpha 3 domain, transmembrane, cytoplasmic, and 3' untranslated region) resulted in a low intensity signal from gametogenic cell fractions and confirmed our findings obtained by PCR. The minimal expression of classical HLA antigens may create a neutral cover for the male reproductive system, thereby preventing an immunological response during germ cell differentiation.

Blotting, Northern↗

Blood platelet function in canine acute pancreatitis with reference to treatment with Nafamostat mesilate (FUT-175).

The aim of this study was to investigate the effect of Nafamostat mesilate (FUT-175) on some blood platelet properties during the first hours of acute experimental pancreatitis (AEP) in dogs. A significant decrease in platelet count, hyperaggregability of platelets by ADP and PAF as well as an increased level of TXB2, were found in the early stage of AEP. No changes in platelet aggregation induced with AA were demonstrated. FUT-175 prevented a decrease in platelet number and inhibited platelet aggregation induced with ADP, PAF and AA when it was given immediately after induction of AEP. No evident changes in TXB2 levels in dogs treated with FUT-175 were found. Our results indicate that the positive effect of FUT-175 in AEP in part depends on its antiaggregatory action.

Acute Disease↗