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Biomedical subjects

A Kiss

Publications and source records attributed to A Kiss.

At least 73 records · Page 4Linked to original sources
PubMed1999

[Laparoscopic intervention in pediatric urology].

The authors summarise the short history of the laparoscopy, and main steps of its use in international and Hungarian practice of urological surgery. They evaluate the possibility of laparoscopy in paediatric urological practice. Finally, they present their experience with this minimally invasive technique from 1995. Between October 1995 and September 1998, 83 laparoscopic procedures were performed. In 59 patients the vena testicularis were ligated by laparoscopy and in 22 patients 24 non palpable testes were diagnosed and operated. In 9 of the cases laparoscopic orchidopexy was performed. The authors demonstrate their operative technique. All laparoscopic interventions were tolerated well by children and they were treated without any complication. Postoperative pain medication were given for 5 children. The operative time for varix ligation ranged from 15 and 20 minutes, and for laparoscopic orchidopexy from 30 and 40 minutes. The recurrence rate of varicocele was found to be 1.5%, and postoperative hydrocele developed in one patient (1.5%).

Adolescent↗
PubMed1999

[Hairy cell leukemia: authors' own experience (1977-1998)].

Hairy cell leukaemia (HCL) is a rare, clinically and haematologically well characterised entity. The prognosis of patients with hairy cell leukaemia has significantly improved due to the new therapeutic approaches. Development of diagnostic and therapeutic methods, together with the analysis of their own hairy cell leukaemia patients, is reviewed by the authors. Between 1977 and 1998 twenty five patients (16 male, 9 female) were treated. The malignant cells were usually analysed by morphological and cytochemical methods and recently flow cytometric analysis could be performed in eight patients. Splenectomy with lethal outcome in six patients was performed in 21 cases. Approximately one third of patients received interferon, while 2-chlorodeoxyadenosine was given only to three patients. Favourable experiences obtained by splenectomy and efficacy of interferon treatment are emphasised, but according to the literature and their own results administration of purine analogues can be highly recommended in the future.

Adult↗
PubMed1999

Pituitary adenylate cyclase activating polypeptide (PACAP) is present in human and cat gastric glands.

In the present work we have studied the occurrence of pituitary adenylate cyclase activating polypeptide (PACAP) in human and cat stomach mucosa using immunohistochemistry. As seen under a light microscope, there were many large rounded and ovoid cells that were PACAP immunopositive, mainly in the neck of the gastric glands of both species. The immunopositive material was predominant in the perinuclear area. The PACAP immunolabeling was specific because the preincubation of the antiserum with PACAP abolished the immunostaining. In human samples under electron microscope, the PACAP immunoreactive cells have shown the characteristics of parietal cells. In faintly stained cells, the localization of DAB reaction product was associated with the surface of the intracellular canaliculi. Cell labeling could not be observed besides parietal cells.

Animals↗
PubMed1999

Central corticotropin-releasing hormone receptors modulate hypothalamic-pituitary-adrenocortical and sympathoadrenal activity during stress.

The role of brain corticotropin-releasing hormone receptors in modulating hypothalamic-pituitary-adrenal and sympathoadrenal responses to acute immobilization stress was studied in conscious rats under central corticotropin-releasing hormone receptor blockade by intracerebroventricular injection of a peptide corticotropin-releasing hormone receptor antagonist. Blood for catecholamines, adrenocorticotropic hormone and corticosterone levels was collected through vascular catheters, and brains were removed at 3 h for in situ hybridization for tyrosine hydroxylase messenger RNA in the locus coeruleus, and corticotropin-releasing hormone and corticotropin-releasing hormone receptor messenger RNA in the hypothalamic paraventricular nucleus. Central corticotropin-releasing hormone receptor blockade reduced the early increases in plasma epinephrine and dopamine, but not norepinephrine, during stress. Immobilization stress increased tyrosine hydroxylase messenger RNA levels in the locus coeruleus by 36% in controls, but not in corticotropin-releasing hormone antagonist-injected rats. In control rats, corticotropin-releasing hormone messenger RNA and type 1 corticotropin-releasing hormone receptor messenger RNA in the paraventricular nucleus increased after stress (P<0.01), and these responses were attenuated by central corticotropin-releasing hormone receptor blockade. In contrast, central corticotropin-releasing hormone antagonist potentiated plasma adrenocorticotropic hormone responses, but slightly attenuated plasma corticosterone responses to stress. The inhibition of plasma catecholamine and locus coeruleus tyrosine hydroxylase messenger RNA responses to stress by central corticotropin-releasing hormone receptor blockade supports the notion that central corticotropin-releasing hormone regulates sympathoadrenal responses during stress. The attenuation of stress-induced corticotropin-releasing hormone and corticotropin-releasing hormone receptor messenger RNA responses by central corticotropin-releasing hormone receptor blockade suggests direct or indirect positive feedback effects of corticotropin-releasing hormone receptor ligands on corticotropin-releasing hormone expression, whereas additional mechanisms potentiate adrenocorticotropic hormone responses at the pituitary level. In addition, changes in neural activity by central corticotropin-releasing hormone are likely to modulate adrenocortical responsiveness during stress.

Adrenal Cortex↗
PubMed1999

The effect of intravesical mitomycin C on the recurrence of superficial (Ta-T1) bladder cancer. A Hungarian Multicenter Study.

We evaluated the prophylactic efficacy of instillations of intravesical mitomycin C in 57 patients with primary superficial bladder cancer in a multicenter clinical trial. After complete transurethral resection of Ta-T1 G1-G2 transitional cell bladder carcinomas, patients were treated with mitomycin 40 mg/50 ml saline of 15 instillations for 12 months. Most of the complications were mild and transient but two patients dropped out of the trial because of moderate side effects. Fifty-one patients were evaluable. We observed tumour recurrences in six patients (11.8%) during a median follow-up of 44.5 months. The recurrences were treated by transurethral resection. There was no muscle invasive progression in the recurrences. Our investigations confirm the effectiveness of mitomycin C in the treatment of patients with superficial bladder cancer.

Administration, Intravesical↗
PubMed1999

DNA nicks inflicted by restriction endonucleases are repaired by a RecA- and RecB-dependent pathway in Escherichia coli.

Two mutants of the EcoRI endonuclease (R200K and E144C) predominantly nick only one strand of the DNA substrate. Temperature sensitivity of the mutant enzymes allowed us to study the consequences of inflicting DNA nicks at EcoRI sites in vivo. Expression of the EcoRI endonuclease mutants in the absence of the EcoRI methyltransferase induces the SOS DNA repair response and greatly reduces viability of recA56, recB21 and lexA3 mutant strains of Escherichia coli. In parallel studies, overexpression of the EcoRV endonuclease in cells also expressing the EcoRV methyltransferase was used to introduce nicks at non-cognate EcoRV sites in the bacterial genome. EcoRV overproduction was lethal in recA56 and recB21 mutant strains and moderately toxic in a lexA3 mutant strain. The toxic effect of EcoRV overproduction could be partially alleviated by introduction into the cells of multiple copies of the E. coli DNA ligase gene. These observations suggest that an increased number of DNA nicks can overwhelm the repair capacity of DNA ligase, resulting in the conversion of a proportion of DNA nicks into DNA lesions that require recombination for repair.

DNA Damage↗
PubMed1999

Elevated hepatic glucocorticoid receptor expression during liver regeneration in rats.

In rats within the first week of partial hepatectomy reconstruction of the normal histological structure of the liver already starts. To approach the possible role of endogenous glucocorticoids in the process of regeneration we measured the changes in the expression of steroid glucocorticoid receptor gene after various regeneration intervals. After partial hepatectomy, between 0.5 168 hours from the surgery, the gene expression (mRNA) of glucocorticoid receptor was determined by reverse transcription followed by PCR and normalized to that of glycerolphoshate dehydrogenase. Two peaks of glucocorticoid receptor mRNA were detected first, between 3 and 6 hours (first peak) and a second between 24 and 36 hours. Immunoreactive glucocorticoid receptor was detected by immunohistochemistry using monoclonal anti-glucocorticoid receptor. Three days after the surgery immunohistochemical studies showed substantially more immunoreactive GcR protein in the regenerated liver than in the controls. These semiquantitative data provide evidence suggesting elevation of glucocorticoid receptor expression during regeneration of liver at mRNA and protein levels.

Animals↗
PubMed1999

Massive true thymic hyperplasia.

A case of massive true thymic hyperplasia in a child of eleven months is described. This rare disorder must be included in the differential diagnosis of a mediastinal mass in children. Diagnosis and management are discussed and the relevant literature is reviewed.

Diagnosis, Differential↗
PubMed1999

Corticotropin-releasing hormone synthesizing neurons in the hypothalamic paraventricular nucleus of rats neonatally treated with monosodium glutamate can respond to different stress paradigms.

Neonatal administration of monosodium glutamate (MSG) produces pathological lesions in many brain regions. There are indications that MSG treatment could also influence the neurons of the hypothalamic paraventricular nucleus (PVN). The goal of this study was to find out whether MSG treatment could alter the activity of the corticotropin-releasing hormone synthesizing neurons, i.e. the principal regulators of the corticotropin hormone secretion, located in the medial posterior subdivision of the PVN. The activity of CRH neurons was assessed by changes in CRH mRNA levels in response to both stimulatory and inhibitory conditions induced by immobilization and water deprivation, respectively. In addition, effect of the circulating glucocorticoid deficit induced by bilateral adrenalectomy was investigated. The obtained data show that in MSG-treated animals the rise in CRH mRNA in response to immobilization stress and adrenalectomy as well as the decrease after water deprivation were similar to the changes seen in controls. In addition POMC mRNA changes in MSG-treated animals indicate an uninterrupted capability of CRH neurons to transform different signals to corticotropin cells. It can be concluded that CRH neurons of the PVN are not functionally altered, in spite of the widespread neurotoxic effect of MSG treatment.

Adrenalectomy↗
PubMed1999

HGF-mediated apoptosis via p53/bax-independent pathway activating JNK1.

Current studies have indicated both positive and negative roles for the hepatocyte growth factor (HGF)/c-met receptor signaling system in tumor development. Recently, we have shown that HGF has the capacity to induce both growth inhibition and programmed cell death in aflatoxin-transformed (AFLB8) rat liver epithelial cells. Using the same cell line, we have now investigated a potential mechanism for HGF-induced apoptosis. Immunoblot analysis of bcl-2 gene family member (bax, bcl-2, bclX-s/l) expression showed no correlation with HGF treatment, suggesting that HGF-mediated apoptosis is bax independent. Following HGF treatment retinoblastoma protein (pRB) was present in the hypophosphorylated state. HGF treatment increased cyclin A, cyclin G1 and nuclear transcriptional factor (NFkappaB) protein expression. However, electrophoretic mobility shift analysis showed that NFkappaB activity decreased with HGF treatment. Under these apoptotic conditions, c-Jun N-terminal kinase (JNK1) and extracellular signal-regulated kinase (ERK2) were activated with lower level activation of ERK2, while no involvement of phosphatidylinositol-3 kinase was observed. Epidermal growth factor (EGF) was not protective, and actually induced cells to undergo apoptosis to a level similar to that of HGF alone or EGF/HGF in combination. These results suggest the possibility of cross-talk between HGF/c-met and EGF/EGFR signaling pathways, and the involvement of JNK1 induction in HGF-mediated apoptotic cell death.

Aflatoxins↗
PubMed1999

Comparison of the toxicity of fluconazole and other azole antifungal drugs to murine and human granulocyte-macrophage progenitor cells in vitro.

We studied the inhibitory effects on colony formation by granulocyte-macrophage colony forming units (cfu-gm) of eight azole antifungal agents in vitro. All agents, except fluconazole, inhibited colony formation dose-dependently with 50% inhibitory concentrations (IC50) in the range of 0.78-49 micromol/L in cultures of murine and human bone marrow. For human cells, the IC50 values were 0.553 mg/L for itraconazole, 1.24 mg/L for saperconazole, 2.58 mg/L for clotrimazole, 5.33 mg/L for miconazole, 6.17 mg/L for econazole, 6.27 mg/L for ketoconazole and 8.38 mg/L for oxiconazole. The IC50 of itraconazole for human cfu-gm in vitro was similar to the plasma level of this drug recommended for systemic antifungal therapy (>0.5 mg/L) thus indicating the potential clinical relevance of our data. The IC50 of ketoconazole for human cfu-gm in vitro may be exceeded by plasma levels produced in vivo by high (> or =400 mg) doses, whereas fluconazole failed to reduce colony formation by 50% even at 100 mg/L, a concentration not reached in vivo even after extremely high doses (2000 mg/day). To most of the drugs studied, murine progenitor cells seemed to be less sensitive than the human ones. There was, however, a close correlation between the murine and human log IC50 values of the drugs (r2 = 0.964, P< 0.001), suggesting that cultures of murine bone marrow may be suitable to predict the in-vitro toxicity of azole antifungals to human cfu-gm.

Animals↗
PubMed1999

Xanthine stone in the urinary bladder of a male child.

Urinary tract calculi composed primarily of xanthine are rate both in adults and children. We describe the clinical presentation and management of a 3.5-year-old boy with hereditary xanthinuria (an autosomal recessive disorder of purine metabolism) and primary bladder calculus formed from xanthine. To our knowledge this case demonstrates a previously undescribed form of xanthinuria in childhood. Xanthine stones, although rare, should be considered in the diagnosis of urolithiasis.

Child, Preschool↗
PubMed1999

Early effects of castration on the vascular system of the rat ventral prostate gland.

Recent studies have found that blood flow to the rat ventral prostate gland is drastically reduced at an early time after castration. These observations caused us to reevaluate the effects of castration on the various cell populations of the ventral prostate, especially those in the prostatic vascular system. Sections of ventral prostate glands obtained at different times after castration were analyzed using the TUNEL (terminal deoxynucleotide transferase-mediated dUTP nick END labeling) staining method to quantify apoptosis in different cell types. The results of this analysis showed a significant increase in TUNEL staining of prostate endothelial and (nonendothelial) stromal cells as early as 12 h postcastration that continued to 24 h after castration. In contrast, TUNEL labeling of prostate epithelial cells was not significantly increased compared with control values until 72 h after castration. The use of dual immunohistochemical staining procedures (anti-CD31 for endothelial cells or antismooth muscle actin for smooth muscle cells combined with TUNEL labeling) allowed us to confirm that the TUNEL-positive vascular cells at these early times after castration were endothelial in nature, whereas smooth muscle cells surrounding the prostate glands or portions of the afferent vascular endothelium were rarely TUNEL labeled. Electron microscopic evaluation of ventral prostate tissues at 48 h after castration provided further morphological evidence for the occurrence of apoptosis in prostate endothelial cells. Finally, the Lendrum-Fraser histochemical procedure used to identify fibrin leakage in tissues with vascular damage was applied to sections of the ventral prostate gland. This stain revealed diffuse fibrin accumulation in periglandular areas outside the capillaries and blood vessels in prostates from 24-h castrated rats, but not in prostates of sham-operated rats. Our results confirm an early effect of castration on the vascular system of the rat ventral prostate identified by increased apoptosis of endothelial cells and vascular leakiness. As these changes temporally precede the loss of epithelial cells, we propose that they may be causal rather than incidental to regression of the rat ventral prostate after castration.

Actins↗
PubMed1999

Neutron yields from 155 MeV/nucleon carbon and helium stopping in aluminum.

Neutron fluences have been measured from 155 MeV/nucleon 4He and 12C ions stopping in an Al target at laboratory angles between 10 and 160 deg. The resultant spectra were integrated over angle and energy above 10 MeV to produce total neutron yields. Comparison of the two systems shows that approximately two times as many neutrons are produced from 155 MeV/nucleon 4He stopping in Al and 155 MeV/nucleon 12C stopping in Al. Using an energy-dependent geometric cross-section formula to calculate the expected number of primary nuclear interactions shows that the 12C + Al system has, within uncertainties, the same number of neutrons per interaction (0.99 +/- 0.03) as does the 4He + Al system (1.02 +/- 0.04), despite the fact that 12C has three times as many neutrons as does 4He. Energy and angular distributions for both systems are also reported. No major differences can be seen between the two systems in those distributions, except for the overall magnitude. Where possible, the 4He + Al spectra are compared with previously measured spectra from 160 and 177.5 MeV/nucleon 4He interactions in a variety of stopping targets. The reported spectra are consistent with previously measured spectra. The data were acquired to provide data applicable to problems dealing with the determination of the radiation risk to humans engaged in long-term missions in space; however, the data are also of interest for issues related to the determination of the radiation environment in high-altitude flight, with shielding at high-energy heavy-ion accelerators and with doses delivered outside tumor sites treated with high-energy hadronic beams.

Altitude↗
PubMed1999

[Synthesis and reactivity of debenzorutaecarpine derivatives].

A series of 7,12-dihydropyrimido[1',2';1,2]pyrido[3,4-b]indol-4(6H)-ones was prepared by Fischer indolization of 9-arylhydrazono-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one s. Quantumchemical calculations (ab initio and AM1) indicate that position 3 of 7,12-dihydro-pyrimido[1',2';1,2]pyrido[3,4-b]indol-4(6H)-one can be involved in electrophilic substitutions, while position 2 is sensitive towards nucleophilic attack. Bromination of 6-methyl-7,12-dihydropyrimido[1',2';1,2]pyrido[3,4-b]indol-4(6H)-o ne (16) with bromine afforded 3-bromo derivative (25), which was reacted with cyclic amines to give 2-amino-7,12-dihydro-pyrimido[1',2';1,2]pyrido[3,4-b]indol-4(6H)-ones (26-30) in an addition-elimination reaction. Vielsmeier-Haack formylation of compound (16) give 12-formyl (31) and 3,12-diformyl (32) derivatives (an N-formyl-1-aza derivative of nauclefidine alkaloid (34) at 60 degrees C and 100 degrees C, respectively. 3,12-dformyl compound (32) was oxidized to 3-carboxyl derivative (33). The quaternary salt (35), obtained from compound (16) with dimethyl sulphate, suffered a ring opening on the action of aqueous sodium hydroxide. The new compounds have been characterized by elemental analyses uv, 1H nmr and in some cases by 13C ruler, CD spectra and X-ray investigations.

Alkaloids↗
PubMed1999

Investigation on the formation of the hormone reception mechanism.

The formation of the hormone receptor mechanism is part of the embryonic development. The perinatal age seems to be critical for the maturation of this system, i.e. the development of the proper hormone selectivity, the number of the receptors, their sensitivity to the adequate hormone. Our team tried to get a closer view on this developmental period examining different parameters in different model systems. We were able to show that during the maturation of the hormonal system similar responses could be elicited by the later specific hormones or by the non-specific ones but structurally similar compounds. Also it became evident that one single hormonal treatment, applied during in the perinatal age, could influence the responsiveness to hormones of the adult animals.

Embryo, Mammalian↗