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Biomedical subjects

M Antal

Publications and source records attributed to M Antal.

At least 19 recordsLinked to original sources
PubMed1998

[Nutritional value of polyunsaturated fatty acids].

Recently, the scientific interest trends toward the role of polyunsaturated fatty acids (PUFAs) in human nutrition because of their multifunctional properties. This study shortly summarizes our knowledge on the metabolism and physiological importance of PUFAs belonging to the n-6 and n-3 families. The main PUFAs of nutritional interest are linoleic (C18:2n-6), alpha-linolenic (C18:3n-3) acids and their derivates, namely arachidonic (C20:4n-6), eicosapentaenoic (C20:5n-3) and docosahexaenoic (C22:6n-3) acids, respectively. These fatty acids are incorporated into membrane phospholipids of cells where they support cell membrane integrity and function. Furthermore, arachidonic and eicosapentaenoic acids are precursors for eicosanoids. Eicosanoids, such as thromboxanes, prostacyclins and leucotrienes are important in the regulation of several physiological processes. PUFAs, especially docosahexaenoic acid are essential nutrients in early human development, namely for neural tissues, such as the brain and the retina. According to our study the n-3 PUFAs supply of pregnant women and neonates were inadequate. In conformity with our calculation the same is true for the whole Hungarian population. On the basis of these findings we call attention to the necessity of changing the structure of fat consumption and we commit to a recommendation for it.

Dietary Fats↗
PubMed1998

Iron status in a healthy population of Hungarian secondary school boys and girls.

Iron status was assessed in a sample of 103 male and 282 female students aged from 15 to 18 years attending secondary schools in Budapest. Using a ferritin model, in boys the prevalence of iron depletion, iron-deficient erythropoiesis and iron-deficient anemia was 3.9, 2.9 and 1.0%, respectively. In girls these values were 9.6, 8.2 and 2.8%, respectively. Males had better eating habits than females. Data for nutrients intake connected with iron status are discussed. The authors recommend the improvement of iron status by dietary means and oppose the indiscriminate iron supplementation.

Adolescent↗
PubMed1998

Lipid status in adolescents born with low birth weight.

The study compared anthropometric parameters and lipid status of adolescent boys and girls (14-16 y) born with LBW or ABW. Values for body weight and height of LBW adolescents were lower than those for ABW's. BMI differed significantly between LBW and ABW boys. In LBW boys, serum LDL-C level was somewhat lower, and the ApoA1 concentration was higher than in ABW's. Other lipid parameters did not differ among the corresponding groups. These data suggest that hypercholesterolemia, which is seen in LBW adults, must develop in older ages, and the irregular lifestyle including improper nutritional habits may promote its occurrence in this vulnerable group.

Adolescent↗
PubMed1997

Localization of last-order premotor interneurons in the lumbar spinal cord of rats.

There is strong evidence that neural circuits underlying certain rhythmic motor behaviors are located in the spinal cord. Such local central pattern generators are thought to coordinate the activity of motoneurons through specific sets of last-order premotor interneurons that establish monosynaptic contacts with motoneurons. After injections of biotinylated dextran amine into the lateral and medial motor columns as well as the ventrolateral white matter at the level of the upper and lower segments of the lumbar spinal cord, we intended to identify and localize retrogradely labelled spinal interneurons that can likely be regarded as last-order premotor interneurons in rats. Regardless of the location of the injection site, labelled interneurons were revealed in laminae V-VIII along a three- or four-segment-long section of the spinal gray matter. Although most of the stained cells were confined to laminae V-VIII in all cases, the distribution of neurons within the confines of this area varied according to the site of injection. After injections into the lateral motor column at the level of the L4-L5 segments, the labelled neurons were located almost exclusively in laminae V-VII ipsilateral to the injection site, and the perikarya were distributed throughout the entire mediolateral extent of this area. Interneurons projecting to the lateral motor column at the level of the L1-L2 segments were also located in laminae V-VII, but most of them were concentrated in the middle one-third or in the lateral half of this area. Following injections into the medial motor column at the level of the L1-L2 segments, the majority of labelled neurons were confined to the medial aspect of laminae V-VII and lamina VIII, and the proportion of neurons that were found contralateral to the injection site was strikingly higher than in the other experimental groups. The results suggest that the organization of last-order premotor interneurons projecting to motoneurons, which are located at different areas of the lateral and medial motor columns and innervate different muscle groups, may present distinct features in the rat spinal cord.

Animals↗
PubMed1997

[Cardiovascular disease-related serum lipid parameters in a Hungarian subpopulation].

The blood samples of 229 volunteers (100 men, aged 35-59 y and 129 women, aged 35-54 y) were randomly selected and analysed for serum lipids (triglyceride, total, HDL- and LDL-cholesterol), apolipoproteins (apolipoprotein A1, A2 and B) and Lp(a). The mean serum level of triglyceride was in the high risk category in males (2.50 +/- 2.27 mmol/L) and in normal range in females (1.31 +/- 0.82 mmol/L). Concentrations of total cholesterol (male: 5.93 +/- 1.16, female: 5.66 +/- 0.99 mmol/L) and LDL-cholesterol (male: 3.72 +/- 0.94, female: 3.55 +/- 0.81 mmol/L) were in the borderline risk category, and up to the 75th percentiles both total cholesterol (male: > 6.71, female: > 6.25 mmol/L) and LDL-cholesterol (male: > 4.38, female: > 4.10 mmol/L) were in the high risk categories. The mean values of HDL-cholesterol and apolipoprotein A1, A2 and B were in the desirable range in both sexes, but apolipoprotein B in males and females (male: > 1.3, female: > 1.29 g/dl) were in the high risk category up to the 75th and 90th percentiles, respectively. The mean levels of serum Lp(a) were 19.5 +/- 25.0 and 21.0 +/- 25.2 mg/dl for men and women, respectively, and up to the 75th percentiles were in the high risk category (> 30 mg/dl) both in males and females.

Adult↗
PubMed1997

Chlamydomonas U2, U4 and U6 snRNAs. An evolutionary conserved putative third interaction between U4 and U6 snRNAs which has a counterpart in the U4atac-U6atac snRNA duplex.

The spliceosomal UsnRNAs U2, U4 and U6 from the green alga Chlamydomonas reinhardtii (Cre) were sequenced using a combination of RNA and cDNA sequencing methods and were compared to other sequenced UsnRNAs. The lengths of Cre U6 and Cre U2 RNAs are similar to those of their higher plant equivalents. Cre U4 RNA is shorter (139 nt) than its counterpart from higher plants (150-154 nt), and contains stem IV and loop D which are absent, with the exception of the Tetrahymena U4 RNA, from the U4 RNAs of other unicellular organisms studied to date. Base-pairing interactions between U6 and U4 RNAs and between U6 and U2 RNAs, identical to those described for mammalian and yeast systems, are structurally feasible in the Cre system. In addition, based on comparative analyses of the predicted U4/U6 RNA duplex from various species, an evolutionary conserved third putative U6-U4 interaction was found. Interestingly, it can also be formed with the recently discovered U6atac and U4atac RNAs. This is a strong support in favor of the possible biological significance of this third putative interaction. Based on comparative analysis, an extension of the earlier described U6-U2 interaction patterns is also proposed.

Alternative Splicing↗
PubMed1997

Maternal and neonatal essential fatty acid status in phospholipids: an international comparative study.

OBJECTIVE: To investigate whether the steady decline in the maternal essential fatty acids (EFA) status during pregnancy observed in Dutch pregnant women is a local or general phenomenon. DESIGN: The EFA status was measured during uncomplicated, singleton pregnancy of healthy women from the Netherlands, Hungary, Finland, England and Ecuador. In addition, the EFA status of their neonates were measured at birth. Fatty acid profiles were analyzed in phospholipids isolated from maternal plasma and from umbilical plasma and cord vessel walls. RESULTS: Considerable differences between these centers were observed in the maternal EFA levels and EFA status indexes. However, the change in the absolute as well as relative amounts of the EFAs followed a similar course in the five populations during pregnancy. The neonatal EFA profiles reflected the differences found in maternal plasma during pregnancy and shortly after delivery. Comparable correlations were found, particularly, between the neonatal and the maternal n-3 fatty acids in the participating groups. CONCLUSIONS: It seems that the reduction in maternal EFA status during pregnancy is a general phenomenon, and is largely independent of differences in dietary habits and ethnic origin. Since the lowest values for certain maternal EFAs in a given country were significantly higher than the highest value of these EFAs throughout pregnancy in other countries, the functional implications of the pregnancy-associated reduction in the maternal EFA status for the fetal and neonatal development is not obvious and needs to be further elucidated.

Adult↗
PubMed1997

Nutritional survey of pregnant women in Hungary.

A nutritional survey of a Hungarian group of pregnant women was carried out. One hundred and twenty nine women aged 25.9 years, entered the study, but only 70 completed all the protocol. Average body weight gain was 12.4 kg and the mean birth weight of the newborns was 3,386 g. Mean energy and nutrient intakes of pregnant women showed similar patterns as in Hungarian non-pregnant women of the same age. The mean energy intake was high (11 MJ), being 10% higher than for non-pregnant women. The mean protein and lipid intakes were also high, 91.9 g and 108.4 g, respectively, exceeding by 7% and 6% the intakes of the non-pregnant women. Dietary intakes of saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) were close to 12% of energy, and the intake of polyunsaturated fatty acids (PUFAs) was 7.6% of total energy. Palmitic acid (16:0), oleic acid (18:1 n-9) and linoleic acid (18:2 n-6) made the greatest contribution to the total peak area of SFAs, MUFAs, and PUFAs, respectively. The ratio of P/S (polyunsaturated/saturated fatty acids) was appropriate: 0.65; however, the ratio of linoleic acid (18:2 n-6), to linolenic acid (18:3 n-3) was high: 16. The cholesterol intake was somewhat lower in pregnant than in non-pregnant women. Complex carbohydrate intake was low (245 g) but it was still by 75% higher than in non-pregnant women. The excess sodium intake (6.3 g) was very similar to that of non-pregnant women. Mean values for retinol, tocopherol, ascorbic acid, cobalamin and copper intakes were higher than the Hungarian Recommended Dietary Allowances (RDA). Thiamine, riboflavin, pyridoxine, niacin, calcium, iron and zinc intakes were insufficient. Data showed an imbalance in the energy and nutrient intakes of Hungarian pregnant women, and this could be harmful for both the mother and pregnancy outcome.

Adult↗
PubMed1996

Direct evidence of an extensive GABAergic innervation of the spinal dorsal horn by fibres descending from the rostral ventromedial medulla.

A long line of studies emphasizes the contribution of serotonergic fibres descending from the rostral ventromedial medulla in the control of spinal nociceptive information processing. A growing body of evidence, however, suggests that the relative contribution of serotonin to the mediation of spinal neuronal activity from the rostral ventromedial medulla may require re-evaluation. It has recently been substantiated that, in addition to the serotonergic fibres, the spinal dorsal horn receives an abundant non-serotonergic projection from the rostral ventromedial medulla. Furthermore, stimulation in the rostral ventromedial medulla could result in a powerful inhibition of nociceptive spinothalamic tract cells without any detectable serotonin release in the dorsal horn. After labelling raphe-spinal axons and axon terminals in the rat by iontophoretic injections of the anterograde axonal tracer Phaseolus vulgaris leucoagglutinin into the central region of the rostral ventromedial medulla (nucleus raphe magnus) and revealing GABA and glycine immunoreactivities of the labelled raphe-spinal terminals and their postsynaptic targets by postembedding immunocytochemical methods, here we demonstrate an extensive GABAergic projection from the rostral ventromedial medulla to the spinal dorsal horn. We show that the majority of the labelled raphe-spinal terminals in laminae I-IIo and IV-V contain GABA and some of the GABA-immunoreactive terminals are also immunoreactive for glycine. We also disclose that GABA-immunoreactive raphe-spinal terminals establish synaptic contacts primarily with GABA- and glycine-negative, presumably excitatory, spinal neurons, including Calbindin-D28k- as well as parvalbumin-immunoreactive cells in both laminae I-IIo and IV-V. The results suggest that volleys in fibres descending from the rostral ventromedial medulla may evoke GABA release from raphe-spinal terminals, and the released GABA, in some cases probably acting together with glycine, might play a crucial, as yet mostly unidentified, role in the inhibition of nociceptive information processing in the dorsal horn of the spinal cord.

Animals↗
PubMed1996

Nutrition survey of the Hungarian population in a randomized trial between 1992-1994.

OBJECTIVE: Collection of data relating to nutrition, nutrient supply and nutritional status, and to certain risk factors of diet-related diseases in a group of Hungarian population. DESIGN: Collection of data on diets three times 24h dietary recall, anthropometric measurements to obtain information about the nutritional status, laboratory tests measurements of biochemical markers. SUBJECT: Examination of 2559 volunteer adult persons, selected in a quasi random way in Budapest and seven other counties. RESULTS: The diets of the persons examined contained more than necessary protein 14.6 en%, considerably more fat 38.0 en%, mainly fat of animal origin with low PUFA and including high cholesterol, little total carbohydrate 45.1 en%, in that much added sugar 15.4 en%. Vitamin supply was generally satisfactory, borderline deficiency may be observed in the case of tocopherol equivalent and in some age-groups, first of all in women, in the case of thiamine, riboflavin and pyridoxine. Out of the macro- and microelements, sodium intake is three to four times the acceptable level, potassium and calcium intakes in both genders, iron and zinc intakes in women show deficiency. The mean value for relative body mass, the distribution of BMI values prove a high incidence of overweight 34.3% and obesity 21.1%. Means for biochemical markers appear to indicate that nutrient supply was in the normal range of laboratory tests. The averages of total cholesterol and LDL-cholesterol 5.6 and 3.6 mmol/L, respectively unequivocally suggested the risk of cardiovascular diseases. CONCLUSIONS: The nutrition of the Hungarian population presents several risk factors of diet-related diseases: P/S ratio of 0.27-0.29, Na/K ratio of 2.6 g/g, intake of some micronutrients (vitamins, macro- and microelements) was low in certain groups of investigated persons.

Adolescent↗
PubMed1996

Three different cell types can synthesize factor XIII subunit A in the human liver.

The origin of human Factor XIII subunit A (FXIII A) has been a subject of intense speculation and investigation during the last decade. The major question under dispute is whether hepatocytes can produce this clotting factor. Experimental evidence obtained by FXIII A phenotype analysis in bone marrow transplant patients clearly identified hemopoietic cells (monocytes/macrophages and/or megakaryocytes/ platelets) as a source of FXIII A, and also showed that additional extra-hemopoietic site(s) of synthesis also exist. The liver has been suggested as a possible extra-hemopoietic source of plasma FXIII A, but the cells responsible for synthesizing FXIII A were not identified yet. Our present study was designed to determine the cellular distribution of both FXIII A and its encoding mRNA in human liver samples by using light- and electron-microscopic immuno-morphological and in situ hybridization techniques. In paraformaldehyde/glutaraldehyde (PA/GA) fixed, araldite-embedded semithin sections that were immunostained by an ABC/DAB based postembedding immunocytochemical method, FXIII A could be detected in Kupffer cells, connective tissue histiocytes and hepatocytes. Immunoreactive hepatocytes were observed almost exclusively around the venae centrales. By using postembedding immunogold labeling, FXIII A could be electron-microscopically visualized in these hepatocytes in the immediate vicinity of the lamellae of the endoplasmic reticulum. By in situ hybridization using a mixture of five 32-40mer biotinylated oligonucleotides (ONs) to mRNA regions encoded by exons VI, XI and XV and a labeling system containing streptavidin conjugated with alkaline phosphatase/BCIP/NBT, the message for FXIII A could be detected in the same cell types. These results show that in human liver three different types of cells can synthesize FXIII A, but the extent of their contribution to the plasma FXIII A level will require further studies.

Humans↗
PubMed1995

Developmental expression of glycine immunoreactivity and its colocalization with GABA in the embryonic chick lumbosacral spinal cord.

The development of immunoreactivity for the putative inhibitory amino acid neurotransmitter glycine was investigated in the embryonic and posthatched chick lumbosacral spinal cord by using postembedding immunocytochemical methods. Glycine immunoreactive perikarya were first observed at embryonic day 8 (E8) both in the dorsal and ventral gray matters. The number of immunostained neurons sharply increased by E10 and was gradually augmented further at later developmental stages. The general pattern of glycine immunoreactivity characteristic of mature animals had been achieved by E12 and was only slightly altered afterward. Most of the immunostained neurons were located in the presumptive deep dorsal horn (laminae IV-VI) and lamina VII, although glycine-immunoreactive neurons were scattered throughout the entire extent of the spinal gray matter. By using some of our previously obtained and published data concerning the development of gamma-aminobutyric acid (GABA)-ergic neurons in the embryonic chick lumbosacral spinal cord, we have compared the numbers, sizes, and distribution of glycine- and GABA-immunoreactive spinal neurons at various developmental stages and found the following marked differences in the developmental characteristics of these two populations of putative inhibitory interneurons. (i) GABA immunoreactivity was expressed very early (E4), whereas immunoreactivity for glycine appeared relatively late (E8) in embryonic development. (ii) In the ventral horn, GABA immunoreactivity declined, whereas immunoreactivity for glycine gradually increased from E8 onward in such a manner that the sum of glycinergic and GABAergic perikarya remained constant during the second half of embryonic development. (iii) Glycinergic and GABAergic neurons showed different distribution patterns in the spinal gray matter throughout the entire course of embryogenesis as well as in the posthatched animal. When investigating the colocalization of glycine and GABA immunoreactivities, perikarya immunostained for both amino acids were revealed at all developmental stages from E8 onward, and the proportions of glycine- and GABA-immunoreactive neurons that were also immunostained for the other amino acid were remarkably constant during development. The characteristic features of the development of the investigated putative inhibitory spinal interneurons are discussed and correlated with previous neuroanatomical and physiological studies.

Animals↗
PubMed1995

The colocalization of parvalbumin and calbindin-D28k with GABA in the subnucleus caudalis of the rat spinal trigeminal nucleus.

The colocalization of two calcium-binding proteins, parvalbumin (PV) and calbindin-D28k (CaB), which have been reported to be markers of specific subpopulations of neurons in the central nervous system, with the inhibitory amino acid neurotransmitter gamma-amino-butyric acid (GABA) was investigated in neurons of laminae I-IV of the subnucleus caudalis of the rat spinal trigeminal nucleus by using post-embedding immunocytochemical methods. Cells immunoreactive for PV, CaB, and GABA were found in all four laminae of the subnucleus caudalis. A substantial proportion of PV-immunoreactive perikarya were also stained for GABA in laminae II and III (44.8% and 39.8%, respectively). However, the majority of PV-containing neurons in laminae I and IV (100% and 86%, respectively), as well as CaB-immunoreactive cells in all four laminae (98.4%), were GABA-negative. These results show that, in contrast to higher brain centers, PV-, CaB-, and GABA-immunoreactive perikarya represent significantly different populations of neurons in the subnucleus caudalis of the rat. In the light of the present findings, the differences in the neurochemical properties of the subnucleus caudalis of the spinal trigeminal nucleus and the spinal dorsal horn are also discussed.

Animals↗
PubMed1995

Serum lipid pattern of adolescents in Hungary.

The authors have measured and compared the lipid parameters in groups of adolescents aged from 15 to 18 years with and without a history of myocardial infarction of parents. No essential differences were seen among the lipid variables of the two groups. Nonetheless in a considerable part of both girls and boys in either group serum total cholesterol and LDL-cholesterol was higher than the "acceptable" values. The authors propose the initiation of an immediate intervention program in the population serving preventive purposes.

Adolescent↗
PubMed1994

Developmental changes in the distribution of gamma-aminobutyric acid-immunoreactive neurons in the embryonic chick lumbosacral spinal cord.

The development of gamma-aminobutyric acid (GABA)-immunoreactive neurons was investigated in the embryonic and posthatch chick lumbosacral spinal cord by using pre- and postembedding immunostaining with an anti-GABA antiserum. The first GABA-immunoreactive cells were detected in the ventral one-half of the spinal cord dorsal to the lateral motor column at E4. GABAergic neurons in this location sharply increased in number and, with the exception of the lateral motor column, appeared throughout the entire extent of the ventral one-half of the spinal gray matter by E6. Thereafter, GABA-immunoreactive neurons extended from ventral to dorsal regions. Stained perikarya first appeared at E8 and then progressively accumulated in the dorsal horn, while immunoreactive neurons gradually declined in the ventral horn. The general pattern of GABA immunoreactivity characteristic of mature animals had been achieved by E12 and was only slightly altered afterwards. In the dorsal horn, most of the stained neurons were observed in laminae I-III, both at the upper (LS 1-3) and at the lower (LS 5-7) segments of the lumbosacral spinal cord. In the ventral horn, the upper and lower lumbosacral segments showed marked differences in the distribution of stained perikarya. GABAergic neurons were scattered in a relatively large region dorsomedial to the lateral motor column at the level of the upper lumbosacral segments, whereas they were confined to the dorsalmost region of lamina VII at the lower segments. The early expression of GABA immunoreactivity may indicate a trophic and synaptogenetic role for GABA in early phases of spinal cord development.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1994

Combination of cobalt labelling with immunocytochemical reactions for electron microscopic investigations on frog spinal cord.

Cobalt staining of primary afferents in frog spinal cord was combined with peroxidase-antiperoxidase pre-embedding or immunogold post-embedding immunocytochemical labelling. Our results have shown that cobalt labelling can easily be distinguished from both of the immunoreaction end products. The protocol of cobalt labelling did not affect the immunoreactivity of structures. The morphology and synaptology of cobalt labelled and immunostained profiles in our sections were very similar to those reported in previous studies using different double labelling techniques. These results indicate that this new combined method could be used as an alternative double labelling technique in electron microscopic studies on nervous tissues.

Animals↗
PubMed1994

Development of specific populations of interneurons in the ventral horn of the embryonic chick lumbosacral spinal cord.

The development, morphological and neurochemical properties of specific populations of interneurons were investigated in the ventral horn of the embryonic and mature chick lumbosacral spinal cord by using pre- and post-embedding immunocytochemical as well as anterograde axonal tracing techniques. We have identified and traced the morphological maturation of the following cell groups: (1) Neurons immunoreactive for calbindin-D 28k (CaB), a calcium-binding protein that has been reported to be a marker of certain subsets of excitatory spinal neurons. We have distinguished and traced the maturation of three CaB-immunoreactive cell groups in the ventral horn; (2) Neurons immunoreactive for GABA and glycine, the two putative inhibitory amino acid neurotransmitters in the spinal cord; (3) Neurons within the nucleus marginalis, a cell group located in the ventrolateral aspect of the white matter in close proximity to the lateral motor column. The characteristic features of the development of these neurons are discussed and correlated with previous neuroanatomical and physiological studies concerning motor functions in the developing chick spinal cord.

Animals↗