Biomedical subjects
Publications and source records attributed to A Antal.
We have performed the first laparoscopic appendectomy in Hungary. Laparoscopic appendectomy is a new, minimally invasive method in abdominal surgery. We consider it a worthwhile alternative to classical appendectomy.
The left somatosensory cortex of PVG/C rats was subjected to a transcranial cold lesion, spontaneous and evoked cortical activity was studied 2-3 weeks after the lesion. The spontaneous activity underwent a depression at the focus of the lesion. Close to the epicentre of the lesion, the amplitude of the potentials evoked by electrical stimulation of the contralateral whisker pad was considerably smaller than in the controls and an almost complete reduction of the initial positive phase was found. Perifocally, 3-4 mm from the epicentre, evoked potentials with enhanced amplitudes were recorded in all experiments. It seems that considerable damage took place at the epicentre of the lesion, while perifocally an excitatory (and/or inhibitory?) mechanism was activated.
The smooth muscle responses to electric stimulation of intact, slightly or severely inflamed, isolated human appendix strips were studied. No changes were noted in the motility of the not inflamed and slightly inflamed appendices, (simple appendicitis), the preparations responded to nervous stimulation with contractions of the same size. The smooth muscle contractions were blocked by atropine, and enhanced by physostigmine, which proves the cholinergic nature of the innervation. The severe inflammation (acute phlegmonous appendicitis) reduced also the contraction and relaxation of the appendix strips. With the advancement of the inflammatory process, the decreased motility of the appendix can play an in vivo role in the rapid progress of the process.
Effects of sodium bromide were studied on central neuroplasticity induced by early binocular enucleation. It has previously been found that enucleation on the day of birth, but not later than the first postnatal week, resulted in changes in the occipital cortex, such as the invasion of somatosensory evoked activity into the visual cortex areas. The present results showed that sodium bromide treatment extended at least up to 15 days after birth, the critical period during which somatosensory projections could be modified by visual deafferentation. Together with observations of Frost [J. comp. Neurol. (1981) 203, 227-256; Devl Brain Res. (1982) 3, 627-636], the present results suggest a mutual dependency of visual and somatosensory projection development. The present study is the first demonstration that the critical period of development, during which a specific type of neural plasticity can be induced, may be prolonged by pharmacological means, i.e. by chronic treatment with sodium bromide.
The technique of ultra-low volume by ultra-light aircraft for pesticide spray application has been discussed for some time in North America, mainly due to the air worthiness of such an aircraft which was not designed to carry appreciable amounts of payload. The risk factor of such application in insect control has not been determined, while applicator exposure to insecticide in ULV application by manual sprayer was assessed. An attempt was made to produce, by a series of field exposure measurements, a set of applicator exposure data for ULV-ULA and to compare the results with the data produced in synthetic pyrethroid application by using a hand-held ULV applicator. The applicator exposure of hand-held operation resulted in as high as 1000 times the exposure of aerial applicators indicating the effect of work practices and man-machine relationships. A delineation of toxic dose for these two types of applications shows that the aerial application could provide some benefits in reducing applicator exposure potential.
The calcium and phosphorus weight concentrations as well as the calcium/phosphorus weight ratio were determined by electron probe microanalysis both peritubularly and intertubularly in the dentine of 25 adults of varying age and sex, originating from our autopsy material. The studies were performed with a TESLA BS-300 scanning electron microscope coupled with an EDAX-149-10 X-ray detector and a BMG-38100 X-ray analyser with an accelerating potential of 15 kV, a sample current of 100 pA and a measurement time of 20 s. Peritubularly the Ca/P weight ratio of the hypermineralized part of the dentine decreases with age and is in close correlation with it (r = -0.9052) and this tendency is significant even at the level of 95% (P less than 0.05). The equation of the regression line is: Y = 37.17 x +139.37 where x is the age and y is the Ca/P weight ratio. The weight concentration of phosphorus is in an even closer correlation with age (r = 0.9712) and this correlation is also significant (P less than 0.01). The equation of the regression line is the following: y = 625.0 x -42.06 The close correlation of both the Ca/P weight ratio of the teeth and of the phosphorus weight concentration with the age allows individual age determination to be performed in the course of forensic medical and palaeoanthropological studies.
Liver resection experiments in dogs made by the AKE telescope compressor are reviewed. It is established that the instrument can be applied to the liver parenchyma of varying size and compressibility. The time of resection is short and the intervention entails only minimal loss of blood. Using this solution, it is not necessary to produce the transitory warm ischaemia of the liver.
Six acrylic tooth stumps were prepared for an evaluation of the marginal quality of crowns produced by spark erosion. Four different methods were used for preparation of the crown margins. Each stump had two different margin preparations. The crowns were fabricated with the aid of spark erosion. Serrated sections were then made for an analysis of marginal defects. The results have shown that the mean size of marginal openings is highly dependent on the preparation method used.
Distribution maps of cortical potentials evoked by mechanical stimulation of different number of contralateral vibrissae were studied. It was found that stimulation of all the contralateral vibrissae led to more extensive activation than the barrel field in the somatosensory cortex. The activation was most widespread when all the vibrissae were synchronously deflected. With reduction of the number of synchronously stimulated whiskers the activated cortical area did not decrease in parallel. Deflection of only a few whiskers activated significantly smaller cortical areas.
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Clinical, microbiological, haematological, and immunological investigations were carried out in mares and their foals of 2 studs. A considerable number of foals fell ill with pneumonia, the mortality rate was high. Mycoplasmas were mostly isolated from nasal swabs and from the lungs. The isolation rate of bacteria was lower. Serum IgG concentration was reduced in the diseased or dead foals compared to that of healthy animals, the data stress in importance of IgG in the development of respiratory diseases also in foals.
The relaxant effect of capsaicin was investigated on isolated segments of guinea pig ileum precontracted by histamine. Two types of relaxation could be distinguished. Low concentrations of capsaicin (0.033-3.3 microM) caused partial relaxation (type I) which was prevented by in vitro desensitization to capsaicin or by extrinsic denervation and reduced by tachyphylaxis to calcitonin gene-related peptide. At higher concentrations (10-100 microM) capsaicin caused relaxation (type II) to the baseline; this effect was insensitive to capsaicin desensitization or extrinsic denervation. Neither type of relaxation was inhibited by tetrodotoxin or by alpha- and beta-adrenoceptor antagonists. We suggest that type I relaxation results from a specific effect of capsaicin on extrinsic sensory neurones of the gut while type II represents a non-specific smooth muscle depressant effect. Intrinsic enteric neurones are not involved in these effects.
By means of histological methods the authors examined the blood and fluid circulatory disturbances associated with cranial and cerebral injuries. The presence of vital reactions was studied by means of the combined histological study of the dura mater, pacchionian granulations and the central nervous system. Samples for histological study were taken from 115 cadavers who had suffered cranial injuries, from 15 individuals who died from destructive cerebral apoplexy caused by a disease and from 30 individuals who died of natural causes. The authors applied a special fixation and sampling technique and, using various histological reactions, the following vital reactions were observed: the appearance of blood-cell elements in the granulation, a moderate fibrin degradation product and hemoglobin phagocytosis, and occasionally lipid phagocytosis. The authors worked out a method that was shown to be highly effective in the more precise determination of the induction time of cerebral apoplexy caused by a disease and that of traumatic injury of the brain.
Prostaglandins (PGs) are essential for many physiological and pathological processes. As they are not stored in tissue, their presence and actions therefore result from de novo synthesis and release. Although platelets themselves appear to have the ability to synthesize TxA2, PGD2, arachidonic acid may also be metabolized in the lipoxygenase pathway in platelets, producing 12-hydroperoxy/12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HPETE/12-HETE). CFLP mice were infected intranasally with A/H3N2/Hong Kong (1/68) influenza virus. Platelets were isolated from the control (saline treated) and infected mice 3-13 days after virus application. Platelets were isolated from the diluted arterial blood of the mice. Metabolites of arachidonate cascade were determined using 1-14C-arachidonic acid (2035 MBq/mM spec. act.) as substrate. All incubations were carried out in TC Medium 199 (pH 7.4) at 37 degrees C for 10 min. Radiolabelled products were separated and quantitatively determined. The synthesis of TxA2 in the platelets of animals was found to be significantly increased 7 days after the virus infection. The 12-hydroxy-heptadecatrienoic acid level was higher on the 10th and 13th days of infection, as were the products of the lipoxygenase pathway.
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Explore the source record for details and available documents.