PubMed Health⌕ Search

Biomedical subjects

M Ugur

Publications and source records attributed to M Ugur.

At least 19 recordsLinked to original sources
PubMed2004

The effect of individualized diet challenges consisting of allergenic foods on TNF-alpha and IL-1beta levels in patients with rheumatoid arthritis.

OBJECTIVE: To investigate the effect of individualized diet challenges consisting of allergenic foods, defined by the skin prick test (SPT), on tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) levels in patients with rheumatoid arthritis (RA). METHODS: Twenty patients with a positive SPT response for food extracts and 20 with a negative SPT response were enrolled. None of the patients had active disease. All patients were fasted for the most common allergenic foods for 12 days and then allocated to two groups according to SPT results. Food challenges were performed with allergenic foods in the prick-positive group (PPG) and with corn and rice in the prick-negative group (PNG) for a period of 12 days. Then, allergenic foods were excluded from the PPG patients' diet and corn and rice were removed from the PNG patients' diet. Clinical examinations were performed after fasting (baseline), at the end of the challenge phase and at the end of the re-elimination phase. Stiffness, pain, tender and swollen joint counts, health assessment questionnaire (HAQ), Ritchie's articular index, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and serum TNF-alpha and IL-1beta levels were measured. RESULTS: TNF-alpha (P < 0.01), IL-1beta (P < 0.05), ESR (P < 0.05) and CRP (P = 0.001) levels and all of the clinical variables, except HAQ, were increased with food challenges in the PPG. These increases were also recorded after the re-elimination phase. In the PNG, no significant change was seen in any of the variables, except pain (P < 0.05). During the study, important differences were observed for most of the variables between the two groups. Thirteen (72%) patients in the PPG and three (18%) in the PNG experienced disease exacerbation with challenges. This aggravation continued after elimination. CONCLUSIONS: Our results suggest that individualized dietary revisions may regulate TNF-alpha and IL-1beta levels in selected patients with RA.

Adult↗
PubMed2004

Correlation between soluble intercellular adhesion molecule 1 level and extracellular superoxide dismutase activity in rheumatoid arthritis: a possible association with disease activity.

OBJECTIVE: We investigated serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) and the activity of extracellular superoxide dismutase (EC-SOD) in rheumatoid arthritis (RA). We also considered whether there was a correlation between sICAM-1 and EC-SOD and disease activity. METHODS: Levels of sICAM-1 were measured in serum from 42 patients with active RA and 30 control subjects by enzyme-linked immunosorbent assay (ELISA). EC-SOD activity was determined in sera isolated from patients with active RA and from controls. RESULTS: The serum levels of sICAM-1 were significantly higher in patients with RA than in control subjects (p<0.001). In contrast, the activity of EC-SOD was significantly lower in RA patients than in healthy controls (p<0.001). A significant negative correlation was found between the levels of sICAM-1 and EC-SOD activity (r=-0.39, p<0.01). There was a statistically positive correlation between sICAM-1 levels with Ritchie articular index (RAI) score and C-reactive protein (CRP) (r=0.32, p<0.05; r=0.44, p<0.01, respectively). CONCLUSIONS: These results show that the increased levels of sICAM-1 present in active RA patients might be due to the decreased activity of EC-SOD, and increased levels of sICAM-1 may also reflect disease status or activity.

Adult↗
PubMed2003

Vegetable oils used as vitamin E vehicle affect the electrical activity of the rat heart.

The aim of this study is to define the possible effects of vegetable oils used as vitamin E vehicle on the electrical activity of the rat heart. To test the possible effects of vitamin E vehicles we studied the effect of i.p. injected corn oil, hazelnut oil or peanut oil on the action potential parameters recorded in both papillary and left atrial muscle strips. Four experimental groups were used. The control group was injected (i.p.) with distilled water, while the three remaining groups received injections of corn oil, hazelnut oil, or peanut oil for five weeks (in a dose of 0.4 ml/kg/day--minimum amount of oil in which vitamin E could be dissolved). We used borosilicated (15-20 megaohms) capillary electrodes and intracellular action potentials (AP) were recorded in isolated papillary and left atrium muscle strips. While administration of three different types of vegetable oil had no significant effect on AP parameters of papillary muscle, they significantly prolonged the repolarization phase of AP in atrial strips. These results show that vegetable oils used as vitamin E vehicles may alter the electrical activity of the heart in a tissue-dependent manner. The present data indicate that the possible effect of vegetable oil vehicles should be kept in mind while evaluating the possible effects of in vivo vitamin E administration.

Action Potentials↗
PubMed2001

Coupling of a P2Z-like purinoceptor to a fatty acid-activated K(+) channel in toad gastric smooth muscle cells.

1. Extracellular application of ATP generates two whole-cell currents in toad gastric smooth muscle cells: an immediate inward non-selective cation current (due to the activation of a P2X or P2Z-like receptor) and a slowly developing outward K(+) current. The inward non-selective cation current depends on the continuous presence of ATP while the outward K(+) current can last for minutes after ATP application ceases. 2. In cell-attached patches, application of ATP to the extra-patch membrane can activate K(+) channels in the patch indicating that a diffusible cellular messenger may be involved. The characteristics of these K(+) channels are similar to those of a previously described fatty acid-activated K(+) channel that is also a stretch-activated channel. 3. This whole-cell K(+) current can be induced by ATP in the absence of extracellular Ca(2+) (with EGTA present to chelate trace amounts). However, the current generated in the presence of extracellular Ca(2+) is considerably larger. 4. The pharmacological profiles for the activation of the non-selective cation current and the K(+) current are similar, suggesting that the same P2Z-like receptor could be mediating both responses. This type of plasma membrane receptor/channel-channel coupling by a process that does not appear to involve Ca(2+) flow through the receptor/channel or a subsequent membrane potential change may be representative of a new class of signalling mechanisms.

Adenosine Triphosphate↗
PubMed2001

Intravenous albumin versus hydroxyethyl starch for the prevention of ovarian hyperstimulation in an in-vitro fertilization programme: a prospective randomized placebo controlled study.

A prospective randomized placebo controlled clinical trial was carried out on 250 patients (cycles) considered at risk of developing OHSS in an IVF programme. Criteria for inclusion were: estradiol value of more than 3000 pg/ml or the presence of more than 20 follicles on the day of hCG administration. Patients were randomized by using a random table to receive either 20% human albumin 50 ml (n: 82); 6% hydroxyethyl starch (200/0.5) 500 ml (n: 85) or a placebo of 500 ml 0.9% NaCl solution (n: 83) over 30 min during oocyte collection. Groups were similar with respect to patients' age, estradiol levels on hCG day, body mass index, number of oocytes retrieved, number of embryos transferred and pregnancies (P>0.05). There was no severe OHSS in patients who received albumin and HES while four patients who received placebo developed severe OHSS. On the other hand moderate OHSS was encountered in four patients in the albumin group; five patients receiving HES; and 12 patients receiving placebo. There was a statistically significant difference in the incidence of moderate, severe and overall OHSS among groups (P values of <0.05, <0.05, and <0.01, respectively). Both HES and albumin significantly reduced the incidence of moderate, severe and overall incidence of OHSS. It is concluded that hydroxyethyl starch is a cheaper and safer alternative to Human Albumin in OHSS prevention.

Adult↗
PubMed2001

Adenosine triphosphate alters the selenite-induced contracture and negative inotropic effect on cardiac muscle contractions.

Selenium is known to play an important role in the physiology of many different cell types and extracellular application of selenite causes cellular dysfunction in many different types of tissues. In a previous study, we have shown that in rat ventricles, sodium selenite (> or = 1 mM) caused an increase in the resting tension and a decrease in contractile force, in a time-dependent manner. In the present study, we have shown that sodium selenite caused a contracture state both in Langendorff perfused hearts and isolated papillary muscles. We also showed that the application of extracellular ATP (0.1 mM) markedly reduced this detrimental effect of sodium selenite on ventricular contraction in Langendorff perfused hearts and delayed it in isolated papillary muscle preparations. In contrast, isoproterenol (0.1 microM) did not seem to influence this action of sodium selenite in papillary muscle preparations. Possible reasons for this protective effect of ATP to selenite-induced contracture are also discussed.

Adenosine Triphosphate↗
PubMed2000

Dietary selenium and vitamin E intakes alter beta-adrenergic response of L-type Ca-current and beta-adrenoceptor-adenylate cyclase coupling in rat heart.

Previously we have shown that both insufficient (combined with vitamin E deficiency) and excess intake of selenium (Se) impairs isoproterenol (ISO)-induced contractions of rat papillary muscle. In the present study, we used patch-clamp and biochemical techniques to investigate mechanisms of this effect in rats fed a Se- and vitamin E-deficient, a Se-excess or a normal diet. Whole-cell configuration of patch-clamp technique was used to investigate L-type Ca(2+) currents (I(Ca,L)) and their regulation by beta-adrenergic receptor stimulation in enzymatically isolated single rat ventricular myocytes. Alteration of Se and vitamin E intake did not affect peak I(Ca,L), but the threshold potential of activation was significantly different among groups. Maximal I(Ca,L) responses to ISO were depressed in both experimental groups, but the EC(50) values were not affected. In the Se-deficient group, basal, ISO- or forskolin-induced adenylate cyclase (AC) activity, measured in cardiac membrane preparations, was reduced when compared to the control, whereas 5' guanylyimidodphosphate (GppNHp) stimulated activity was unaffected. Decreased beta-adrenoceptor density and reduced GppNHp-induced affinity shift in ISO binding were also observed in the deficient group. No such differences were present in the excess group. These results suggest that combined Se and vitamin E deficiency interferes with beta-adrenoceptor-AC coupling, whereas excess intake of Se does not affect it. Thus, in the deficient group, the impairment of I(Ca) responses to ISO may be a result of a defect in beta-adrenoceptor-AC pathway. Impairment of I(Ca) response in the excess group, however, appears to have a different underlying mechanism.

Adenylyl Cyclases↗
PubMed1999

Pregnancies achieved after frozen-thawed pronuclear oocytes obtained by intracytoplasmic sperm injection with spermatozoa extracted from frozen-thawed testicular tissues from non-obstructive azoospermic men.

The use of frozen-thawed testicular tissue as a source of spermatozoa for intracytoplasmic sperm injection (ICSI) in non-obstructive azoospermia yields favourable fertilization and pregnancy rates while avoiding both repetitive biopsies and unexpected cycle cancellations. Spermatozoa were obtained from frozen-thawed testicular biopsy specimens from 67 non-obstructive azoospermic men. Following fertilization, supernumerary two pronuclear (2PN) oocytes were frozen. After thawing, 17 cycles of embryo transfer were carried out with a mean number of 2.7 embryos and a mean cumulative embryo score (CES) of 18.3 per transfer. The clinical pregnancy and implantation rates per transfer in these cycles (23.5 and 8.3% respectively) were comparable to those of fresh embryo transfers (35.7 and 12.7% respectively) with a mean number of 2.7 embryos and a mean CES of 28.7 per transfer. Abortion rates, although higher with cryopreserved 2PN oocytes were not significantly different. With this approach, cryopreservation of supernumerary 2PN oocytes can be used to improve the cumulative pregnancy rates in a severely defective spermatogenetic population. To our knowledge, these are the first pregnancies reported which have been obtained by the transfer of cryopreserved pronuclear oocytes obtained from ICSI using cryopreserved testicular spermatozoa.

Adult↗
PubMed1998

(S)-Albuterol increases intracellular free calcium by muscarinic receptor activation and a phospholipase C-dependent mechanism in airway smooth muscle.

Racemic albuterol has been one of the most widely used beta2-adrenoceptor agonists for the relief of the symptoms of asthma, yet the use of beta2 agonists has been known to induce bronchial hyperresponsiveness. To probe a possible role of the S-enantiomer for hyperresponsiveness, we determined the effects of (S)-albuterol on intracellular Ca2+ concentration ([Ca2+]i) in dissociated bovine tracheal smooth muscle cells. Both (S)-and (R,S)-albuterol increased [Ca2+]i at concentrations of >10 pM and 1 nM, respectively, with a maximal response by 150 and 100 nM, respectively. (S)-Albuterol (1 and 10 muM) induced Ca2+ oscillations, reaching 1-2 muM [Ca2+]i. This response is in a stark contrast to that of (R)-albuterol, which decreased [Ca2+]i. The increase in [Ca2+]i was blocked by 100 nM atropine or 500 nM 4-diphenylacetoxy-N-methylpiperidine but was insensitive to the beta2 antagonist ICI 118,551 (10 muM). (S)-Albuterol (10 muM) increased inositol-1,4,5-trisphosphate levels by 213 +/- 34.4% (p < 0.05, four experiments) in cells exposed for 30 sec. The sustained phase of the Ca2+ increase was absent in Ca2+-free solution, suggesting that Ca2+ influx was responsible for the sustained Ca2+ response. The results also suggest that (S)-albuterol may cross-react with muscarinic receptors. As a Ca2+ agonist in airway smooth muscle, (S)-albuterol may have profound clinical implications because 50% of prescribed racemic albuterol is composed of (S)-albuterol.

Adrenergic beta-Agonists↗
PubMed1997

P2X7 purinoceptor expression in Xenopus oocytes is not sufficient to produce a pore-forming P2Z-like phenotype.

The purinergic rP2X7 receptor expressed in a number of heterologous systems not only functions as a cation channel but also gives rise to a P2Z-like response, i.e. a reversible membrane permeabilization that allows the passage of molecules with molecular masses of > or = 300 Da. We investigated the properties of rP2X7 receptors expressed in Xenopus oocytes. In two-electrode voltage-clamp experiments, ATP or BzATP caused inward currents that were abolished or greatly diminished when NMDG+ or choline replaced Na+ as the principal external cation. In fluorescent dye experiments, BzATP application did not result in entry of the fluorophore YO-PRO-1(2+). Thus, rP2X7 expression in Xenopus oocytes does not by itself give rise to the pore-forming P2Z phenotype, suggesting that ancillary factors are involved.

Adenosine Triphosphate↗
PubMed1997

An ATP-gated cation channel with some P2Z-like characteristics in gastric smooth muscle cells of toad.

1. Whole-cell and single-channel currents elicited by extracellular ATP were studied in freshly dissociated smooth muscle cells from the stomach of the toad Bufo marinus using standard patch clamp and microfluorimetric techniques. 2. This ATP-gated cation channel shares a number of pharmacological and functional properties with native rat myometrium receptors, certain native P2Z purinoceptors and the recently cloned P2X7 purinoceptor. But, unlike the last two, the ATP-gated channel does not mediate the formation of large non-specific pores. Thus, it may represent a novel member of the P2X or P2Z class. 3. Extracellular application of ATP (> or = 150 microM) elicited an inward whole-cell current at negative holding potentials that was inwardly rectifying and showed no sign of desensitization. Na+, Cs+ and, to a lesser degree, the organic cation choline served as charge carriers, but Cl- did not. Ratiometric fura-2 measurements indicated that the current is carried in part by Ca2+. The EC50 for ATP was 700 microM in solutions with a low divalent cation concentration. 4. ATP (> or = 100 microM) at the extracellular surface of cell-attached or excised patches elicited inwardly rectifying single-channel currents with a 22 pS conductance. Cl- did not serve as a charge carrier but both Na+ and Cs+ did, as did choline to a lesser extent. The mean open time of the channel was quite long, with a range in hundreds of milliseconds at a holding potential of -70 mV. 5. Mg2+ and Ca2+ decreased the magnitude of the ATP-induced whole-cell currents. Mg2+ decreased both the amplitude and the activity of ATP-activated single-channel currents. 6. ADP, UTP, P1, P5-di-adenosine pentaphosphate (AP5A), adenosine and alpha, beta-methylene ATP (alpha, beta-Me-ATP) did not induce significant whole-cell current. ATP-gamma-S and 2-methylthio ATP (2-Me-S-ATP) were significantly less effective than ATP in inducing whole-cell currents, whereas benzoylbenzoyl ATP (BzATP) was more effective. BzATP, alpha, beta-Me-ATP, ATP-gamma-S and 2-Me-S-ATP induced single-channel currents, but a higher concentration of alpha, beta-Me-ATP was required. 7. BzATP did not induce the formation of large non-specific pores, as assayed using mag-fura-2 as a high molecular mass probe.

Adenosine Triphosphate↗
PubMed1996

Transvaginal sonographic diagnosis of ovarian endometrioma.

OBJECTIVE: To assess the efficacy of transvaginal sonography (TVS) in differentiating endometriomas from other adnexal masses. METHODS: One thousand thirty-five adnexal masses undergoing laparoscopy or laparotomy were evaluated prospectively using TVS. Masses diagnosed as endometrioma according to their sonographic appearance were divided into two groups: those with a round shape, regular margins, thick walls and homogeneous, low-level echoes (group A); or those with irregular margins, internal septations and an anechoic appearance (group B). RESULTS: The sensitivity of TVS in diagnosing endometriomas was 86.50% and the specificity 99.11%. The positive predictive value (PPV) and the negative predictive value of the test were calculated to be 91.45% and 98.14%, respectively. By using the criteria determining group A, the PPV of the test increased to 97%, whereas group B had a lower PPV (70.85%). CONCLUSION: We propose that the accuracy of TVS in diagnosing endometriomas may be beneficial in various clinical conditions.

Adnexal Diseases↗
PubMed1996

Reproductive outcome after metroplasty.

OBJECTIVE: To evaluate the impact of abdominal metroplasty for symmetric uterine anomalies on reproductive performance. METHOD: A retrospective analysis of 24 patients who conceived following metroplasty for symmetric congenital anomalies during a 5-year period. RESULTS: In patients with poor obstetric histories before surgery, the overall fetal survival rate increased from 2.5%, before treatment to 73.3% after treatment and 90.5% of women gave birth to a surviving infant. The remaining three patients suffering from infertility delivered a full-term infant after metroplasty. Antenatal complications occurred in 56.7% of the pregnancies. CONCLUSION: Abdominal metroplasty clearly improves fetal survival particularly in women suffering from a history of poor obstetric outcome associated with symmetric malformations.

Abortion, Spontaneous↗
PubMed1996

Vulvar syringoma exacerbated during pregnancy.

Although syringoma of the eyelids and the cheeks are well known and defined, vulvar syringoma is a rare clinical variant of this benign eccrine tumor. A case of syringoma of the vulva exacerbated during pregnancies with regression in the periods in between is presented. Histopathological examination showed typical features of syringomas. Only 20 patients with vulvar syringoma have been previously reported in the literature.

Female↗
PubMed1996

Transvaginal sonographic findings of chronic ectopic pregnancy.

Chronic ectopic pregnancy is not precisely defined in gynecologic and sonographic texts. The diagnosis of this enigmatic clinical condition is frequently not made until laparotomy. In the present retrospective study, we evaluated the transvaginal sonographic findings of cases who were diagnosed as chronic ectopic pregnancy intraoperatively and/or postoperatively. The incidence of chronic ectopic pregnancy was found to be 20.3% (62/305) of all ectopic pregnancies. Of these 62 cases, 55 had transvaginal sonographic examination. On transvaginal sonographic examination, all 55 cases of chronic ectopic pregnancy had a complex adnexal mass with an empty uterus and only 18 (32.7%) had simple fluid in the pelvis/cul-de-sac. In the majority of cases (82.7%, n = 48), there was a non-homogeneous echo pattern within the adnexal mass. Of 55 cases, 30 had color Doppler flow examination, of whom none had color Doppler flow imaging on the wall of the mass or within the mass. There was a negative quantitative beta human chorionic gonadotropin (beta-hCG) assay (i.e. 0 mIU/ml) in only 4 cases. Based on this study, we concluded that chronic ectopic pregnancy is not a rare clinical entity and should be considered in differential diagnosis among patients presenting with an adnexal mass and an overt clinical picture. Transvaginal sonography is sensitive in diagnosing chronic ectopic pregnancy, but not specific. The combined use of transvaginal ultrasonography and beta-hCG assay increases diagnostic accuracy. However, it should be kept in mind that a negative beta-hCG value does not rule out chronic ectopic pregnancy.

Adnexa Uteri↗
PubMed1996

Combined use of a long-acting gonadotropin-releasing hormone agonist and low-dose danazol in advanced stage endometriosis.

In this preliminary study, the safety and efficacy of a combined GnRHa and low-dose danazol regimen was evaluated in patients with advanced stage endometriosis. Five patients with stage IV endometriosis were administered triptorelin 3.75 mg intramuscularly with monthly intervals in combination with oral danazol 100 mg/day for 6 months. Laparoscopy was performed before and after therapy to assess the change in endometriotic lesions. During controls, patients were evaluated for the change in hormonal and biochemical parameters and the side effects of the treatment. In 4 patients with ovarian endometriomas, cysts were drained during initial laparoscopy. None of the endometriomas persisted after therapy. Total scores, according to the revised American Fertility Society classification of endometriosis were, 54.8 +/- 10.9 before treatment and decreased to 31.6 +/- 10.3 (P < 0.05), whereas, endometriotic implants scores changed from an initial value of 22.8 +/- 12.1 to 1.2 +/- 1.1 (P < 0.05). No adverse effect was observed on lipid and liver metabolism. Estrogen deprivation symptoms and oily skin were the most prominent complaints and one patient had a weight gain of 6 kg. Based on these results we conclude that a combination of GnRHa and low dose danazol is an effective alternative treatment modality in the treatment of severe endometriosis without any serious side effect.

Adult↗