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Biomedical subjects

K Kovács

Publications and source records attributed to K Kovács.

At least 19 recordsLinked to original sources

[Haemodialysed, hemiparetic patient operated on for aortic aneurysm followed by successful renal transplantation].

The authors present the case of a 58 years old male patient. According to his preceding record in 1991 he suffered speech disturbance and left-side hemiparesis due to multiplex vascular lesions. A fresh cerebral ictus caused a right side hemiparesis mainly in the upper limb in 1993 and sensomotororic aphasia has also been developed. In 1995 the patient was begun acute haemodialysis treatment due to his gravis uremic state, then his dialysis was continued 3 times 4 hours weekly. In 1997 the then 56 years old inveterate right-sided hemiparetic patient, treated with chronic haemodialysis requested to be put on the transplantation waiting list. The first thing that had to be done in case of this high-risk patient was the resection of the abdominal aortic aneurysm (38 mm x 67 mm x 115 mm in size) noticed at the ultrasound examination which was carried out in January 1997. The continuity of the vessel was secured by graft-interposition where the arteria mesenterica was also implanted. Following the successful operation, the patient was qualified for the transplantation list and in the February of 1998 a successful kidney-transplantation was carried out. Following the temporary, post-transplantation difficulties (post-operative 5th day acute rejection well-reacting to 3 steroid-shots; the two re-operations due to partial necrosis in the uretero-ureteralis anastomosis and successfully overcoming the Pseudomonas aeruginosa uroinfection) the patient is currently doing well and has no complaint.

Aortic Aneurysm, Abdominal↗

[Ovulation induction therapy and malignant ovarian cancer].

In the authors' institute 1097 patients received treatment for ovarian cancer between the 1st of January, 1960 and the 31st of December, 1997. 92 of them had malignant granulosa cell tumor. In this study the link between ovulation induction therapy and ovarian cancer was analyzed with retrospective questionnaire. 236 questionnaires were shared out among patients with malignant ovarian tumor, who were treated between 1990 and 1997. 7 of 113 patients, who gave correct answers to the questions (6.2%) received ovulation induction therapy. Epithelial ovarian cancer developed in 2 of the cases during, and in 5 cases just 6-16 years after the clomiphene-citrate treatment. None of the 45 patients with granulosa cell tumors received induction therapy. The number of patients admitted because of malignant ovarian tumor before and after the induction therapy was also compared. There was no significant increase in the occurrence of the malignancy. Since 1986 in the in vitro fertilization program of the clinic nearly 1,500 patients were treated with effected ovulation induction drugs causing superovulation. The authors don't know of any development of malignant ovarian tumor, and 732 woman have confirmed this fact. The number of patients deceased in consequence of ovarian cancer in different age groups, and the distribution of the women population in every age group in Hungary, from the year of 1979 was also analyzed. There was no significant increase found in the number of deceased among the studied age groups, moreover a significant decrease among them could be observed. The link between ovulation induction therapy and ovarian cancer can neither be strengthen, nor deny by the result of the study, however the close relationship which seemed to be logical can be queried. To give an exact answer for the question a vast, long-term, prospective of retrospective follow-up case-control study is needed.

Adult↗

The effects of medium-strength electric impulses on human blood.

Leukocyte subsets, total leukocyte isolates or full blood samples were subjected to medium-strength square-wave electric impulses (100 V/cm field force, 5 ms duration). On the surface of the leukocytes, the expressions of several markers (CD3, CD4, CD8, CD11a, CD11b and ICAM-1) were determined in order to study the influence of pulsed ionic currents on different aspects of the cellular immune response. Large individual differences were observed among randomly chosen healthy donors, both in the initial expression rate and in the response patterns of different antigens. As a general conclusion, it can be stated that electric impulses with the above parameters activate the state of immune response alertness of human leukocytes. Changes in the activities of several enzymes in the serum in response to electric impulses were also tested in order to examine the feasibility of ex vivo electric treatment of human blood for the establishment of an antiviral and immune activated condition. Slightly elevated lactate dehydrogenase (LDH) levels point to a possibility of enhanced haemolysis, while the lack of an elevation in the membrane-bound peroxidase activity indicates the absence of haemolysis. Significant rises were detected in the serum superoxide dismutase (SOD) activities. Since most ex vivo blood manipulations are characterised by the appearance of superoxide radicals in the serum, a SOD activity enhancement is considered beneficial in these cases. A mild, but significant reduction in the blood clotting time indicates that electric treatment of human blood should be performed with special attention to thrombosis-prone conditions, and adequate precautions and countermeasures should be introduced. Although wider examinations are required before this method can be fully recommended, ex vivo blood treatment with medium-strength electric impulses seems to be a promising adjuvant course for the establishment of acute immune potentiation and an antiviral state in patients undergoing dialysis treatment.

Antigens, CD↗

[Tin compounds in pharmacy and nutrition].

The occurrence of tin in plants, animals and humans is discussed, in relation to its abundance in the lithosphere and hydrosphere and the range of the different tin(II) and tin(IV) complexes formed. A reasoned consideration of its essentiality for living species is provided. It is concluded that tin is beneficial, even if not yet proved to be an essential element. After reference to the chemistry of tin compounds, there is a detailed discussion of their toxicity in animals and humans. Feasible routes for tin intake and uptake into humans are described. The past and current use of tin pharmaceuticals is reviewed and the areas for which they are currently permitted for use in humans as dentifrices and mouth washes, as radio-pharmaceuticals and for the treatment of jaundiced newborns are described. A detailed review of tin-containing antitumour agents as representative tin pharmaceuticals is also given. Finally, a list of tin-containing drugs and drug candidates is also shown.

Animal Nutritional Physiological Phenomena↗

[Therapeutic results in patients with malignant granulosa cell tumors at the Gynecologic Clinic of the city of Pécs].

In the Department of Obstetrics and Gynecology, University Medical School of Pecs, Hungary 92 patients had been treated with malignant human granulosa cell tumor between 1960-1997. The youngest patient was 14 years old, the oldest 77. The average age was 52.5 years. The disease occurred mostly in 50-60 year old women, and most of them have never given birth before. In 64 cases (69%) metrorrhagia and low abdominal pain were the leading symptoms. 61% of cases the disease was diagnosed in the 1st stage, 14% in the 2nd, 18.5% in the 3rd, and 6.5% in the 4th stage. According to the endometrial histologic examination, data of increased estradiol production was found in 75% of the patients. Along with granulosa cell tumor breast cancer occurred in 2 cases, endometrial carcinoma was diagnosed in 4 cases, and atypical endometrial hyperplasia in 6 cases. After the operation 67 patients received radiation therapy, 5 chemotherapy and 16 combined radiation and chemotherapy. The 2 year survival rate of the 87 patients treated between 1960-1994 was 87.4% the 5 year survival rate was 64.4%. In the stage 1 had 92.4% of patients lived 2 years tumor free, 83.0% lived 5 years without recurrence of tumor. The cleaned 5 year survival rate was found in 88%. With the survey of the youngest patient's case the authors pointed out the highly malignant, rapid course, and the changing of the sera hormones during the therapy.

Adolescent↗

[Chylothorax after blunt chest trauma].

An unusually lately discovered and successfully treated case with right sided chylothorax after blunt chest trauma is presented. Pathogenesis of chylothorax, diagnostic and treatment modalities are summarised.

Chylothorax↗

Alterations in corticotropin-releasing hormone gene expression of central amygdaloid neurons following long-term paraventricular lesions and adrenalectomy.

Corticotropin-releasing hormone messenger RNA expression in the amygdala of rats after adrenalectomy and bilateral lesions of the hypothalamic paraventricular nucleus was examined by in situ hybridization histochemistry. Corticotropin-releasing hormone messenger RNA-containing cells are abundant in the intermediate subdivision of the central amygdaloid nucleus. Some corticotropin-releasing hormone-labeled cells are scattered in other subdivisions of the central nucleus and throughout the anterior amygdaloid area. Five days after bilateral adrenalectomy, the number of corticotropin-releasing hormone messenger RNA-containing cells was reduced both in the central nucleus and the anterior area of the amygdala. This reduction was prevented by corticosterone replacement and contrasts sharply with the known rise of corticotropin-releasing hormone messenger RNA in the paraventricular nucleus after adrenalectomy. Corticotropin-releasing hormone messenger RNA expression in the amygdala was up-regulated in rats with six-week bilateral lesions of the paraventricular nucleus. This elevation in corticotropin-releasing hormone messenger RNA was not influenced by adrenalectomy or corticosterone, and it did not correlate with plasma levels of adrenocorticotrophic hormone or corticosterone. The possible direct innervation of the amygdala by the paraventricular nucleus is supported by the demonstration of labeled axons from the paraventricular nucleus to the amygdala after injection of an anterograde tracer, Phaseolus vulgaris leucoagglutinin, into the paraventricular nucleus. Labeled fibers take two courses: through the lateral hypothalamus ventral amygdalofugal path and through the stria terminalis. Data presented here suggest that the paraventricular nucleus-amygdala connection is likely to be inhibitory to corticotropin-releasing hormone neurons in the central amygdala. These neurons may participate in behavioral responses to stress effected through brainstem autonomic centers rather than directly through the hypothalamo-pituitary adrenal axis.

Adrenalectomy↗

Corticotropin-releasing hormone expression in supraoptic neurons after bilateral lesioning of the paraventricular nucleus in rats.

In situ hybridization histochemistry was used to demonstrate corticotropin releasing hormone (CRH) mRNA expression in the supraoptic nucleus of rats. Labeled cells with a range of grain densities were located mainly in the dorsal area of the nucleus. Long-term (6-weeks) lesioning of the hypothalamic paraventricular nucleus, which eliminates the major CRH pool from the hypothalamo-hypophyseal system resulted in an increased CRH mRNA density within supraoptic neurons compared to within sham-operated rats. Adrenalectomy failed to effect CRH mRNA content either in sham-operated or paraventricular-lesioned animals. CRH gene expression in supraoptic neurons of long-term paraventricular lesioned rats may exhibit a compensatory mechanism in the hypothalamus by which supraoptic neurons can take over some of the functions of the lesioned paraventricular CRH cells.

Adrenocorticotropic Hormone↗

Compression of the pituitary stalk elicits chronic increases in CSF vasopressin, oxytocin as well as in social investigation and aggressiveness.

The neurochemical and behavioural effects of a novel stereotaxic surgical method developed for interrupting the nerve fibres running through the rat pituitary stalk to the posterior pituitary gland was studied. The cerebrospinal fluid (CSF) vasopressin (AVP) and oxytocin (OT) content as well as changes in aggressiveness were measured in rats one week and one month after the surgical intervention. The main results are as follows: (1) the compression of the pituitary stalk elicits a chronic increase in water consumption, as well as in CSF vasopressin and oxytocin content; (2) the surgical intervention increased the frequency of clinch fighting after one week. The increase in aggressiveness accentuated after one month and, in addition, operated animals showed reduced scores of resting while exploratory and social behaviours increased; (3) there was a strong positive correlation between water consumption, vasopressin, and aggressiveness; (4) oxytocin changes showed a positive correlation with variation in social behaviour. The surgical intervention may serve as a model for lesions of the pituitary stalk and formation of ectopic neurohypophyses in humans.

Aggression↗

Current principles in the surgical treatment of lung cancer.

The success of surgery performed for pulmonary carcinoma is based on the selection of the patients for operation. Cytological or histological verification of the tumour prior to surgery is important as concerns the choice of the type of surgery and the complex antitumour therapy. It is currently considered that patients with tumours in stages I, II and IIIa are suitable for surgery. Operations are also performed in cases involving solitary cerebral metastases, and centrally-lying tumours which reach the bifurcation carina or the lower portion of the trachea (T4) are similar rarely resectable. The basic operation for pulmonary carcinoma is lobectomy. In selected cases of squamous cell carcinomas in stage T1N0, atypical wedge resection too may be considered. Extended surgery is also performed, depending on the size of the tumour. For all types of tumours, it is essential to take a sample from the lymph nodes for accurate staging. Prospective randomized clinical trials on 288 patients undergoing resection for pulmonary cancer revealed that extended medistinal lymphadenectomy improved the 5-year survival rate in cases of adenocarcinomas and squamous cell carcinoma, involving lymph node metastases. Intraoperative cytological examinations or frozen sections are extremely important as concerns the indication of extended mediastinal lymphadenectomy and adjuvant antitumour treatment.

Clinical Trials as Topic↗

The functional neuroanatomy of corticotropin-releasing factor.

Descriptions of the central distribution of corticotropin-releasing factor (CRF) have been taken as generally supporting the proposition that this neuropeptide is involved in the mediation of complementary neuroendocrine, autonomic and behavioural responses to stress. The hypothalamic paraventricular nucleus (PVN) is recognized as the principal source of CRF in hypophysial portal plasma; CRF mRNA and peptide expression in parvocellular neurosecretory neurons are regulated negatively by adrenal steroids and positively by many stressors. Consistent with the latter, the hypophysiotropic zone of the PVN receives a rich, and biochemically differentiated, afferent supply that provides visceral, somatic and special sensory systems with access to the 'CRF neuron'. Within the PVN, CRF is also expressed, and differentially regulated, in oxytocinergic magnocellular neurosecretory neurons and in autonomic-related projection neurons. CRF expression in at least some extrahypothalamic cell groups (olfactory bulb, Barrington's nucleus) is responsive to certain stressful stimuli, but not to perturbations of the steroid environment. Refinement of our understanding of the central distribution of CRF has been provided by the recognition that most CRF antisera cross-react with an amidated dipeptide encoded by the melanin-concentrating hormone precursor, and by the likelihood that some central sites of CRF peptide expression may be muted or masked by the presence of a CRF-binding protein (CRF-BP). The CRF-BP is expressed prominently in the telencephalon, where it is co-localized with CRF in some neurons, and in anterior pituitary corticotrophs.

Afferent Pathways↗

The diurnal rhythm in vasopressin V1a receptor expression in the suprachiasmatic nucleus is not dependent on vasopressin.

The mammalian suprachiasmatic nucleus is the site of the circadian rhythm generator. The degrees of expression there of several neuropeptides, including vasopressin and vasoactive intestinal polypeptide, follow a diurnal rhythm. The vasopressin V1a receptor, whose activation results in phosphoinositol hydrolysis and mobilization of intracellular calcium, is expressed in this nucleus. This study used double simultaneous hybridization histochemistry to show that V1a receptor transcripts are present in both vasopressin and vasoactive intestinal polypeptide neurons and that their levels follow a diurnal rhythm. Furthermore, the expression of the V1a receptor is 12 h out of phase from that of vasopressin. However, the receptor's diurnal rhythm is still maintained in the vasopressin-deficient Brattleboro rat, indicating that the V1a receptor's rhythm is independent of any vasopressin feedback.

Animals↗

Suboccipital cerebrospinal fluid and plasma concentrations of somatostatin, neuropeptide Y and beta-endorphin in patients with common migraine.

The somatostatin-like (SLI), the neuropeptide Y-like (NPY-LI), and the beta-endorphin-like (BE-LI) immunoreactivities of cerebrospinal fluid (CSF) obtained by suboccipital puncture, or plasma from patients suffering from common migraine or other neuropsychiatric disorders were analysed. The SLI concentration was tendentiously decreased in the migraine patients during the attack-free period compared to that of a 'mixed neuropsychiatric group'. During the migraine attack the level of SLI was further decreased. Similar alteration was found in the CSF BE-LI, while the BE-LI in the plasma showed only a tendentious decrease in common migraine patients. The NPY-LI did not change during the attack period in the CSF or plasma. These findings may indicate the possible role of somatostatin in the pathogenesis of common migraine, and support earlier observations that beta-endorphin is involved in the development in this disorder.

Adult↗

Presynaptic inhibitory effect of TNF-alpha on the release of noradrenaline in isolated median eminence.

The effect of tumor necrosis factor-alpha (TNF-alpha) on the stimulation-evoked release of noradrenaline (NA) from isolated rat median eminence (ME) was investigated, using a low-volume perfusion system. Median eminence, loaded with [3H]noradrenaline, was superfused with Krebs solution and stimulated electrically (2 Hz, 120 shocks). The effect of TNF-alpha was studied on the S2/S1 ratio. It was found that stimulation-evoked release of NA from noradrenergic axon terminals in the isolated rat ME was inhibited by TNF-alpha and this effect was concentration-dependent. In contrast, TNF-alpha had no effect on the release of [3H]NA from the spleen. Since NA released in the ME might be involved in the modulation of corticotropin-releasing factor (CRF) production, it is suggested that TNF-alpha, through presynaptic modulation of NA release from noradrenergic nerve terminals in the ME, might regulate CRF and other neurohormone release in this hypothalamic structure.

Analysis of Variance↗

Lipopolysaccharide is able to bypass corticotrophin-releasing factor in affecting plasma ACTH and corticosterone levels: evidence from rats with lesions of the paraventricular nucleus.

Stimulation of the immune system or experimental conditions (bacterial lipopolysaccharide (LPS) treatment) provoke a broad spectrum of physiological responses. It was recently shown that one of them is the activation of the hypothalamic-pituitary-adrenal (HPA) axis. The mechanism and the site or sites through which LPS stimulates the HPA axis are not well understood. To establish whether the effect of bacterial LPS is related in vivo to the presence of hypothalamic hypophysiotrophic peptides (corticotrophin-releasing factor-41, arginine vasopressin, etc.), plasma ACTH and corticosterone levels were monitored in intact and sham-operated rats, and in rats with paraventricular nucleus lesions in order to remove the main source of these neuropeptides. Evidence was obtained that 4 h after treatment, LPS was able to activate the hypophysial-adrenal system in the absence of hypophysiotrophic neuropeptides of paraventricular origin. It is suggested that, in vivo, LPS could have a direct effect on the pituitary gland or that it acts through an extrapituitary, non-paraventricular pathway to activate the HPA axis.

Acute-Phase Reaction↗

Corticotropin-releasing hormone-containing neurons in the hypothalamo-hypophyseal system in rats six weeks after bilateral lesions of the paraventricular nucleus.

Corticotropin-releasing factor-like immunoreactive nerve fibers and varicosities are present in the pituitary stalk and median eminence 6 weeks after bilateral lesioning of the hypothalamic paraventricular nucleus. The total immunoreactivity may reach 10% of the control density. The origin of these fibers was investigated 3 days after hypothalamic transections in paraventricular-lesioned (6 weeks postoperatively) rats. Accumulations of corticotropin-releasing factor immunostaining were observed in the proximal portions of the transected axons and in neuronal perikarya. Fibers with retrograde labeling were seen lateral and dorsolateral from the sagittally oriented knife cuts which transected the retrochiasmatic area and cells were found in the supraoptic nucleus and in the perifornical nucleus (dorsal-dorsolateral to the fornix), ipsilateral to the lesion. No corticotropin-releasing factor immunostained cells were seen in other hypothalamic or preoptic nuclei which project to the median eminence or the posterior pituitary. Corticotropin-releasing factor containing cells in the supraoptic and perifornical nuclei may have an importance in stress response in rats with long-term paraventricular lesions.

Animals↗