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Biomedical subjects

M Antal

Publications and source records attributed to M Antal.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1993

Development of calbindin-D28k immunoreactive neurons in the embryonic chick lumbosacral spinal cord.

The development of immunoreactivity for the calcium-binding protein calbindin-D28k (CaB) was investigated in the embryonic and hatched chick lumbosacral spinal cord. CaB-immunoreactive neurons were revealed in the dorsal and ventral horns as well as in the intermediate grey matter from early stages of neuronal development. CaB immunoreactivity was first detected in large neurons in the presumptive dorsal horn at embryonic day 5, while small neurons in the lateral dorsal horn were the last to appear, at embryonic day 10. We have identified and traced the morphological maturation of six CaB-immunoreactive cell groups, three in the dorsal horn and three in the ventral horn. In the dorsal horn these groups were (1) large neurons in the lateral dorsal horn (laminae I and IV), (2) small neurons in the lateral dorsal horn (lamina II), and (3) small neurons in the medial dorsal horn (lamina III). All three groups were present throughout the entire length of the lumbosacral spinal cord and showed persistent CaB immunoreactivity. In the ventral horn, CaB-immunoreactive neurons were classified into the following three categories: (1) Neurons dorsal to the lateral motor column (lamina VII). These neurons were present exclusively in the upper lumbosacral segments (LS1-3), and they showed steady CaB immunoreactivity during their maturation. (2) Neurons at the dorsomedial aspect of the lateral motor column (at the border of laminae VII and IX). This population of neurons was characteristic of the lower segments of the lumbosacral cord (LS5-7) and presented transient CaB expression. (3) Neurons within the lateral motor column (lamina IX). These neurons were dispersed throughout the length of the lumbosacral spinal cord. They were three to four times more numerous in the upper than in the lower lumbosacral segments, and their numbers declined throughout LS1-7 as the animal matured. The characteristic features of the development of neurons immunoreactive for CaB are discussed and correlated with previous neuroanatomical and physiological studies concerning sensory and motor functions of the developing chick spinal cord.

Animals↗
PubMed1993

Effect of sex hormones on copper, zinc, iron nutritional status and hepatic lipid peroxidation in rats.

Sex dependence of copper, zinc, iron nutritional status and hepatic lipid peroxidation was studied in gonadectomized, hormone substituted and sham-operated male and female rats. The experiment was performed on H-Wistar rats (106 +/- 10 g) fed conventional laboratory food ad libitum for 12 weeks. The estrogen dependence of copper status is fully confirmed by the results of this study. In hormonally active females the malondialdehyde production was depressed which is supposed to be connected with high copper and low triglyceride levels in the liver. The anaemia observed in estrogen substituted rats may be a result of lower lipid peroxidation rate. The levels of retinol and alkaline phosphatase activity in sera are probably influenced by estrogen action. It is suggested that testosterone leads to acceleration of lipid peroxidation.

Animals↗
PubMed1992

The termination pattern and postsynaptic targets of rubrospinal fibers in the rat spinal cord: a light and electron microscopic study.

The spinal course, termination pattern, and postsynaptic targets of the rubrospinal tract, which is known to contribute to the initiation and execution of movements, were studied in the rat at the light and electron microscopic levels by using the anterograde tracer Phaseolus vulgaris-leucoagglutinin (PHA-L) in combination with calbindin-D28k (CaBP), gamma-aminobutyric acid (GABA), and glycine immunocytochemistry. After injections of PHA-L unilaterally into the red nucleus, labelled fibers and terminals were detected at cervical, thoracic, and lumbar segments of the spinal cord. Most of the descending fibers were located in the dorsolateral funiculus contralateral to the injection site, but axons descending ipsilaterally were also revealed. Rubrospinal axon terminals were predominantly found in laminae V-VI and in the dorsal part of lamina VII at all levels and on both sides of the spinal cord, but stained collaterals were also seen in the ventrolateral aspect of Clark's column and in the ventral regions of lamina VII on both sides. The proportion of axonal varicosities revealed on the ipsilateral side varied at different segments and represented 10-28% of the total number of labelled boutons. Most of the labelled boutons were engaged in synaptic contacts with dendrites. Of the 137 rubrospinal boutons investigated, only 2 were found to establish axosomatic synaptic junctions in the lumbar spinal cord contralateral to the PHA-L injection. With the postembedding immunogold method, 80.8% of dendrites establishing synaptic contacts with rubrospinal terminals did not show immunoreactivity for either GABA or glycine, whereas 19.2% of them were immunoreactive for both amino acids. Rubrospinal axons made multiple contacts with CaBP-immunoreactive neurons in laminae V-VI. Synaptic contacts between rubrospinal terminals and CaBP-immunoreactive dendrites were identified at the electron microscopic level, and all CaBP-containing postsynaptic dendrites investigated were negative for both GABA and glycine. The results suggest that rubrospinal terminals establish synaptic contacts with both excitatory and inhibitory interneurons in the rat spinal cord, and a population of excitatory interneurons receiving monosynaptic rubrospinal input is located in laminae V-VI.

Animals↗
PubMed1992

Development of spinal motor networks in the chick embryo.

We have examined the cellular and synaptic mechanisms underlying the genesis of alternating motor activity in the developing spinal cord of the chick embryo. Experiments were performed on the isolated lumbosacral cord maintained in vitro. Intracellular and whole cell patch clamp recordings obtained from sartorius (primarily a hip flexor) and femorotibialis (a knee extensor) motoneurons showed that both classes of cell are depolarized simultaneously during each cycle of motor activity. Sartorius motoneurons generally fire two bursts/cycle, whereas femorotibialis motoneurons discharge throughout their depolarization, with peak activity between the sartorius bursts. Voltage clamp recordings revealed that inhibitory and excitatory synaptic currents are responsible for the depolarization of sartorius motoneurons, whereas femorotibialis motoneurons are activated principally by excitatory currents. Early in development, the dominant synaptic currents in rhythmically active sartorius motoneurons appear to be inhibitory so that firing is restricted to a single, brief burst at the beginning of each cycle. In E7-E13 embryos, lumbosacral motor activity could be evoked following stimulation in the brainstem, even when the brachial and cervical cord was bathed in a reduced calcium solution to block chemical synaptic transmission. These findings suggest that functional descending connections from the brainstem to the lumbar cord are present by E7, although activation of ascending axons or electrical synapses cannot be eliminated. Ablation, optical, and immunocytochemical experiments were performed to characterize the interneuronal network responsible for the synaptic activation of motoneurons. Ablation experiments were used to show that the essential interneuronal elements required for the rhythmic alternation are in the ventral part of the cord. This observation was supported by real-time Fura-2 imaging of the neuronal calcium transients accompanying motor activity, which revealed that a high proportion of rhythmically active cells are located in the ventrolateral part of the cord and that activity could begin in this region. The fluorescence transients in the majority of neurons, including motoneurons, occurred in phase with ventral root or muscle nerve activity, implying synchronized neuronal action in the rhythm generating network. Immunocytochemical experiments were performed in E14-E16 embryos to localize putative inhibitory interneurons that might be involved in the genesis or patterning of motor activity. The results revealed a pattern similar to that seen in other vertebrates with the dorsal horn containing neurons with gamma-aminobutyric acid (GABA)-like immunoreactivity and the ventral and intermediate regions containing neurons with glycine-like immunoreactivity.

Animals↗
PubMed1992

Synapses on motoneuron dendrites in the brachial section of the frog spinal cord: a computer-aided electron microscopic study of cobalt-filled cells.

Cobalt-labelled motoneuron dendrites of the frog spinal cord at the level of the second spinal nerve were photographed in the electron microscope from long series of ultrathin sections. Three-dimensional computer reconstructions of 120 dendrite segments were analysed. The samples were taken from two locations: proximal to cell body and distal, as defined in a transverse plane of the spinal cord. The dendrites showed highly irregular outlines with many 1-2 microns-long 'thorns' (on average 8.5 thorns per 100 microns 2 of dendritic area). Taken together, the reconstructed dendrite segments from the proximal sites had a total length of about 250 microns; those from the distal locations, 180 microns. On all segments together there were 699 synapses. Nine percent of the synapses were on thorns, and many more close to their base on the dendritic shaft. The synapses were classified in four groups. One third of the synapses were asymmetric with spherical vesicles; one half were symmetric with spherical vesicles; and one tenth were symmetric with flattened vesicles. A fourth, small class of asymmetric synapses had dense-core vesicles. The area of the active zones was large for the asymmetric synapses (median value 0.20 microns 2), and small for the symmetric ones (median value 0.10 microns 2), and the difference was significant. On average, the areas of the active zones of the synapses on thin dendrites were larger than those of synapses on large calibre dendrites. About every 4 microns 2 of dendritic area received one contact. There was a significant difference between the areas of the active zones of the synapses at the two locations. Moreover, the number per unit dendritic length was correlated with dendrite calibre. On average, the active zones covered more than 4% of the dendritic area; this value for thin dendrites was about twice as large as that of large calibre dendrites. We suggest that the larger active zones and the larger synaptic coverage of the thin dendrites compensate for the longer electrotonic distance of these synapses from the soma.

Animals↗
PubMed1992

Hepatic lipid peroxidation and trace elements--nutritional status in streptozotocin-induced diabetic rats.

The aim of this experiment was to study the interrelationships between nutritional status of chosen trace elements (Cu, Zn, Fe) and hepatic lipid peroxidation in streptozotocin-induced diabetic rats. Both copper accumulation and disruption of iron storage were observed in livers of diabetic rats. MDA 0' (baseline) and MDA 30' (produced) levels measured in the liver were negatively correlated with blood glucose levels. MDA 30' levels correlated positively with iron concentration in the liver. It is supposed that the hormonal lability during experimental diabetes caused changes in metabolism of trace elements, and subsequently influenced the rate of lipid peroxidation.

Animals↗