Search PubMed⌕ Search

Biomedical subjects

A Balogh

Publications and source records attributed to A Balogh.

At least 55 records · Page 3Linked to original sources
PubMed2000

N-arginine dibasic convertase (nardilysin) isoforms are soluble dibasic-specific metalloendopeptidases that localize in the cytoplasm and at the cell surface.

N-arginine (R) dibasic (NRD) convertase (nardilysin; EC 3.4.24.61), a metalloendopeptidase of the M16 family, specifically cleaves peptide substrates at the N-terminus of arginines in dibasic motifs in vitro. In rat testis, the enzyme localizes within the cytoplasm of spermatids and associates with microtubules of the manchette and axoneme. NRD1 and NRD2 convertases, two NRD convertase isoforms, differ by the absence (isoform 1) or presence (isoform 2) of a 68-amino acid insertion close to the active site. In this study, we overexpressed both isoforms, either by vaccinia virus infection of BSC40 cells or transfection of COS-7 cells. The partially purified enzymes exhibit very similar biochemical and enzymic properties. Microsequencing revealed that NRD convertase is N-terminally processed. Results of immunocytofluorescence, immunoelectron microscopy and subcellular fractionation studies argue in favour of a primary cytosolic localization of both peptidases. Although the putative signal peptide did not direct NRD convertase into microsomes in an in vitro translation assay, biotinylation experiments clearly showed the presence of both isoforms at the cell surface. In conclusion, although most known processing events at pairs of basic residues are achieved by proprotein convertases within the secretory pathway, NRD convertase may fulfil a similar function in the cytoplasm and/or at the cell surface.

Animals↗
PubMed2000

[Minimally invasive adrenalectomy with posterior retroperitoneoscopy].

Authors report a total of 14 adrenalectomies performed from a posterior (lumbotomy) approach, using minimally invasive retroperitoneoscopic technique. The "UltraCision" scalpel, an ultrasound activated cutter-coagulation device has been used for operative tissue dissection. Two cases were converted. The mean operating time of the successful 12 cases were 128 minutes. No mortality and no septic complication occurred. The mean operative blood loss of the 12 procedures were less than 100 ml. The mean hospitalisation was 3-5 days, and the complete recovery needed 2-3 weeks. On the basis of our own experiences and the ones of prospective, randomized clinical studies of the literature, the retroperitoneoscopic adrenalectomy from a posterior approach is recommended for the surgical treatment of benign tumours of the suprarenal gland with a size less than 5 cm diameter. The low conversion- and complication-rate, the minimal operative blood loss, the short hospitalization and quick recovery time all are the advantages of this method. It can be performed after previous abdominal operation and in cases with morbid obesity. The technique is suitable for bilateral adrenalectomies as well. This method is not justified for the removal of malignant and/or larger than 5 cm adrenal tumours. Coagulopathies are contraindications.

Adrenalectomy↗
PubMed2000

Identification of comet Hyakutake's extremely long ion tail from magnetic field signatures

Observations of the varying orientations of comet tails led to the suggestion of the existence of the solar wind--a continuous outflow of ionized material from the Sun. It is now well established that gas from comets is ionized by several processes and joins the solar wind, forming an ion (plasma) tail that points away from the Sun. The plasma environments of three comets have been measured in situ, but only in the upstream direction or less than 8,000 km downstream of the nucleus. Here we report a fortuitous crossing by a spacecraft of the plasma tail of comet Hyakutake (C/1996 B2), at a distance of more than 3.8 astronomical units (550 million kilometres) from its nucleus. This surpasses the tail length of 2 AU determined for the Great March Comet of 1843 (C/1843 D1). Our measurements reveal that, at this distance, the tail of comet Hyakutake was a structured entity at least 7 million kilometres in diameter.

Journal Article↗
PubMed2000

[Total mesorectal excision with ultrasonic coagulation knife ("UltraCision") in surgery of rectal cancer].

The authors report a total of 62 middle and low third rectal cancer cases operated on by total mesorectal excision by the method of Heald. The oncological basis of this procedure is the horizontal regional metastatization of rectal cancer. The total mesorectal excision facilitates, the low anterior resections and preservation of sphincter with an ultra-low colorectal, or coloanal anastomosis using the double stapling technique. In the authors' experience, the "UltraCision" cutting-coagulating device permits an atraumatic, bloodless and oncologically correct dissection. Using the double stapling technique, we succeeded in 60% of our middle- and low-third rectal cancer patients to perform a sphincter preserving low anterior resection. In 9 (28%) of the low third rectal cancer patients, preservation of the sphincter was possible with oncologically correct anterior resection and an ultra-low colo-anal anastomosis. Three anastomotic insufficiencies occurred, two of them healed on lotion-suction drainage, and one on the application of transient protective ileostomy. The literature data suggest a lower local recurrency rate after radical rectal cancer surgery, if total mesorectal excision is performed.

Adult↗
PubMed2000

Exogenous neopterin causes cardiac contractile dysfunction in the isolated perfused rat heart.

Neopterin is known in humans as a sensitive marker for diseases associated with increased activity of the cellular immune system. Recent studies report neopterin also to exhibit distinct effects: neopterin induces inducible nitric oxide synthase expression in rat vascular smooth muscle cells and activates translocation of nuclear factor- kappa B. Neopterin may also induce oxidative stress causing apoptotic cell death, or superinduce tumor necrosis factor- alpha -mediated apoptosis. Observing these effects in cell cultures, we were interested in possible consequences of neopterin on cardiac function in the isolated perfused rat heart. The influence of neopterin in three different concentrations (10 micromol/l, 50 micromol/l, 100 micromol/l) on cardiac contractility parameters and coronary vascular resistance were studied in 67 male Sprague-Dawley rats using the temperature-controlled and pressure-constant Langendorff apparatus with retrograde perfusion of the aorta with a Krebs-Henseleit buffer. Treatment with 100 micromol/l neopterin resulted in a significant decrease in coronary flow and cardiac contractility. Coronary flow decreased from 15.2 to 9.5 ml/min (P=0.002), left ventricular pressure from 80 to 52 mmHg (P=0. 002), rate of pressure fall from 1605 to 923 mmHg/s (P=0.001) and rate of pressure rise from 2862 to 1709 mmHg/s (P=0.001). Concentrations lower than 100 micromol/l neopterin had no significant effect on cardiac function. Our study demonstrates a considerable influence of exogenous neopterin on cardiac performance in the Langendorff model of isolated perfused rat hearts. This has to be considered a potential pathogenic factor of cardiac disturbances in diseases in which high concentrations of neopterin are released due to immune activation. At present the exact mechanism remains unclear.

Animals↗
PubMed2000

Lipoma of the liver: a differential-diagnostic problem.

BACKGROUND AND AIMS: Lipomatous tumors of the liver are extremely rare; most of them are found incidentally at autopsy. Appropriate methods of the diagnosis of these lesions are ultrasonography (US), computed tomography (CT) and biopsy. CASE REPORT: The case of a 65-year-old man who had undergone an upper-rectum resection because of exulcerated adenocarcinoma of the rectum is described. Six months later, routine control examination revealed a solid tumor in the left lobe of the liver. The tumor was not demonstrated by either sonography or CT before the operation. Repeated US, CT scan and fine-needle biopsy could not exclude the possibility of a metastatic tumor secondary to previous malignancy. The lesion was removed by wedge resection and was proven to be a lipoma. CONCLUSION: Despite adequate preoperative examination (CT, biopsy and US), an anamnestic adenocarcinoma of the rectum can lead to inappropriate therapy. The inadequate result of our therapeutic policy can be explained by the extremely rare incidence of lipoma of the liver.

Adenocarcinoma↗
PubMed2000

Effects of two oral contraceptives on plasma levels of insulin-like growth factor I (IGF-I) and growth hormone (hGH).

UNLABELLED: In 18 healthy women, the effect of two oral contraceptives (OCs) on insulin-like growth factor (IGF-I) and its binding protein-3 (IGFBP-3) and growth hormone (hGH) plasma level were studied before and after intake of either of two OC formulations over 21 days, one containing 2 mg dienogest and 0.03 mg ethinylestradiol (group A) and the other 0.125 mg levonorgestrel and 0.03 mg ethinylestradiol (group B). There was a reduction of the mean IGF-I concentration of 30% (p = 0.008) in the women receiving dienogest-containing pills and 12% (p = 0.006) in women taking the levonogestrel-containing preparation. This difference between drug groups was statistically significant (p = 0.002). A correlation between the control values and the basal-treatment difference (r = 0.945; p = 0.000) was observed only in women of group A. Between basal and treatment cycles the mean plasma levels of hGH remained unchanged in both groups tested, but the 23.5-h integrated mean hGH plasma concentrations (AUC(0-23.5h)) were significantly elevated by 36% (p = 0.016) in comparison to basal values before treatment only in women receiving the levonorgestrel-containing pills. Also, in the women who received the dienogest-containing preparation, the changes of integrated mean plasma level were inversely associated with the control values (r = -0.723; p = 0.025). Neither in group A nor in group B was the mean plasma level of IGFB-3 changed. IN CONCLUSION: the results of the present analysis indicate that hormonal contraceptives can modulate the GH and IGF-I-axis in the reproductive age. Probably the androgenic progestogen levonorgestrel (0.125 mg/day) opposes the estrogen-induced action. In the women who took the dienogest-containing formulations (anti-androgenic progestogen-group A), the extent of individual changes (hGh and IGF-I) depends on the basal level prior to pill intake. Further studies, especially of long-term intake of OCs, are necessary to confirm these results and to assess the practical relevance for possible effects on connective tissue and bone.

Contraceptive Agents, Female↗
PubMed2000

Water enema CT examination of rectum cancer by reduced amount of water.

OBJECTIVE: To define whether volume of water, administered during water enema CT (WE-CT) for local staging of rectal cancer, may be reduced without compromising the diagnostic value of the examination. MATERIALS AND METHODS: 29 patients with rectum cancer underwent preoperative WE-CT. Contrast-enhanced CT (equilibrium phase) measurements were performed after i.v. injection of smooth muscle relaxant and rectal administration of 400-500 ml lukewarm tap water. Quality of the obtained scans was evaluated and the images were analyzed for depth of tumor invasion. Results of the CT examinations were compared to findings at surgery. RESULTS: Despite reduced dose of water enema, 19/29 examinations were of excellent quality, 6/29 good, and 4/29 poor, but still diagnostic. We achieved sensitivity (90.1), specificity (70.1) and accuracy (86.2) in differentiating tumors confined to the bowel wall from those extending beyond it. CONCLUSION: Large volume of water enema administered during CT examination of the rectum may cause complaints and increases the risk of complications. Our results prove that using lower amount of water does not impair the quality of examination and accuracy of local staging of rectum carcinomas.

Aged↗
PubMed2000

Augmentative treatment of chronic deafferentation pain syndromes after peripheral nerve lesions.

Deafferentation pain syndromes developing after peripheral nerve lesions are difficult to treat. According to the follow-up (mean: 39.5 months) of 6 patients suffering from causalgic pain we will present our method of augmentative therapy in chronic neuropathic pain caused by peripheral nerve lesions, i.e., peripheral nerve stimulation (PNS), spinal cord stimulation (SCS) and chronic intrathecal opioid infusion. None of the patients showed intraoperative or follow-up complications. Evaluated by visual analogue scales all patients reported a good to excellent pain relief (75-100%). (1) Regarding the favourable long-term results of PNS, this method should be considered in cases of mononeuropathic pain syndromes. (2) Neuropathic pain syndromes which are not assignable to a singular nerve lesion, can often be managed effectively by SCS. (3) In contrast to the widespread opinion, deafferentation pain syndromes of central or peripheral origin can be treated satisfactorily by intrathecal opiate administration.

Adult↗
PubMed2000

Long-term pharmacological treatment of generalized anxiety disorder.

Generalized anxiety disorder (GAD) is one of the most common anxiety disorders and has a poor prognosis, although it is often thought to be a minor complaint. This disorder has a chronic course of 5-15 years and longer. Long-term treatment with the commonly used benzodiazepines is controversial because of concerns over tolerance and dependence. We performed a thorough search of the literature for clinical trials of a duration of over 2 months conducted in patients with generalized anxiety disorder in order to identify any successful long-term treatment of this disorder. Only eight long-term reports of studies conducted in well-defined homogeneous groups of patients diagnosed with generalized anxiety disorder were found with the methodology of these studies presenting a number of limiting factors. The results are inconclusive and no reference drug could be identified. In addition, an adequate evaluation of the long-term treatment of GAD has not yet been performed.

Anti-Anxiety Agents↗
PubMed2000

Comparison of the vasorelaxing effect of cromakalim and the new inodilator, levosimendan, in human isolated portal vein.

In the present study the vasorelaxing capacity of cromakalim, an ATP-sensitive potassium-channel (KATP channel) activator, and that of levosimendan, a new positive inotropic and vasodilating drug with calcium sensitizing and potassium-channel-activating properties, were compared in human isolated portal vein. Based on the 50% effective concentrations (EC50), levosimendan was found to be about 16-fold more potent (EC50 = 0.281+/-0.03 microM) as a relaxing agent than cromakalim (EC50 = 4.53+/-0.12 microM) in noradrenaline-precontracted portal venous preparations. Glibenclamide, the known inhibitor of KATP channels, was able to prevent the cromakalim-induced venodilation completely. Glibenclamide (15 microM) decreased the quasi-maximal effect of levosimendan (at 1.27 microm by about 60%) and also the effects of those submicromolar concentrations of the inodilator (at 0.1 microM by 23%, at 0.3 microM by 27% and at 0.7 microM by 19%, on average) which were therapeutically effective in preliminary human studies. These findings indicate that, in the human portal vein, both cromakalim and levosimendan are powerful vasorelaxants and that a considerable part of the relaxing effect induced by levosimendan is of cromakalim type.

Adolescent↗
PubMed2000

[Effect of conditioning on the circulation of rat teeth].

Materials employed in "adhesive filling technique" often lack informative instructions concerning the depth of cavities which require lining. Etching-materials directly placed on the dentin can adversely influence the pulp leading to changes in local microcirculation which can be an early sign of the pathological changes in the pulp. Therefore, it is worth examining the effect of these materials on the diameters of pulpal vessels. In the present study we examined wether acid etching (test1: 15 s and test2: 60 s) alters the blood circulation of the pulp lower incisors, by applying it directly onto a thin layer of pulpal wall (40-50 microns) without any liner, and following the instructions provided by the manufacturer. Twenty male Sprague-Dawley rats (weighing 330 +/- 51 g) and the technique of vitalmicroscopy was used for this investigation. The left lower incisors of the rats were prepared for vitalmicroscopy. Changes in vessel diameter were recorded prior to and 5, 15, 30 and 60 minutes after investigated materials or saline (control) were administered on dentin. In control and test1 group the vessel diameter was unchanged during the experiment. However, in group test2 an intense vasoconstriction was registered. There were significant (p > 0.05, ANOVA) differences in diameter changes between the control group and those treated with acid etching for 60s. Our results suggest that extended etching time may affect the circulatory system in the dental pulp, when applied onto very thin layer of dentin.

Acid Etching, Dental↗
PubMed1999

[The effect of a one-year alendronate therapy on postmenopausal osteoporosis. (Results in Hungary of an international multicenter clinical study)].

The FOSIT (Fosamax International Trial) was a placebo-controlled, double blind trial, to determine the effects of daily oral dose of 10 mg alendronate-sodium (Fosamax) or placebo, for one year in postmenopausal osteoporotic women. It was an international, multicenter study; the 153 centers distributed over 34 countries. The number of patients was 1908. Authors report the data of the only Hungarian study site, Debrecen. Twenty women [age (mean +/- SD) 62 +/- 8 years with bone mineral density--BMD--< or = 0.98 g/cm2 at the lumbar spine by LUNAR DPX densitometer] were enrolled into the study and randomly assigned to oral alendronate 10 mg daily or placebo (10 patients in each group). Patients in both groups received 500 mg of calcium. Bone density measurements were performed by dual x-ray absorptiometry (DXA) at months 0, 3, 6, and 12 at the lumbar spine and at the femoral neck. Biochemical indices of bone turnover [bone specific alkaline phosphatase (bAP) and urinary N-telopeptide/creatinine ratio (NTx/crea] were also measured every three months. Percent change of the BMD measurements from baseline at one-year in the alendronate group was +6% and in the placebo group -0.7% on the lumbar spine (p < 0.001). Alendronate treatment increased the bone mineral density in the femoral neck, the trochanter, the Ward's triangle and the total hip by +3.2, +1.6, +3.5, +2.2% respectively, meanwhile the changes in the placebo group were -1.2%; -0.7%; -0.9%; -0.8%, respectively, the difference was not significant. Urinary NTx/crea decreased by 70.6% in the alendronate group and by 9.4% in the placebo group, while bAP decreased by 47.4% in the alendronate group and 15.2% in the placebo group (p < 0.001). In conclusion, after one year of treatment with alendronate induced increase of bone mineral density at the lumbar spine and decreased the bone turnover as compared to the placebo group.

Aged↗
PubMed1999

[Speech activation SPECT measurements in the determination of hemispheric dominance].

Cognitive activity leads to an increased regional cerebral blood flow (rCBF) and energy metabolism in both cerebral hemispheres. In order to assess the reliability of rCBF-SPECT measurements in hemispheric dominance (Broca's area) speech activation SPECT studies were performed in nine patients. Patients (men, n = 6; women, n = 3, mean age: 33.8 +/- 13.8 years) with diagnosis of epilepsy (n = 7) and AVM (n = 2) participated in the preoperative study. Two SPECT studies were performed in each case, one in rest, and one during speech activation. 740 MBq of 99mTc-HMPAO/ECD was injected and stereo TCD monitoring was performed during the three minutes of speech activation. The acquisition was performed by a dual-head ADAC Solus Epic Atlas SPECT camera (ADAC Laboratories, Milpitas, USA). RCBF SPECT measurements were analyzed visually and by a special region-of-interest (ROI) program. The hemispheric dominance profiles were established on the basis of the respective blood flow velocity values obtained by fTCD and cortical hyperperfusion measured by SPECT. The neuropsychological test battery, used in the present study, was developed in our institute. The results of rCBF-SPECT studies highly correlated with the lateralization of hemispheric dominance measured by fTCD. There was a significant increase of rCBF in the inferior posterior frontal cortex (Broca's area, p < 0.0003). The non-invasive speech activation rCBF-SPECT measurement is a highly reliable and useful method in the determination of hemispheric dominance. SPECT studies are especially useful in cases where the performance of fTCD measurements are impossible due to the lack of temporal bone window or occlusive cerebral arterial disease.

Dominance, Cerebral↗