Biomedical subjects

Sándor Nagy

Publications and source records attributed to Sándor Nagy.

5 recordsLinked to original sources

PubMed2006

Intestinal nitric oxide synthase activity changes during experimental colon obstruction.

OBJECTIVE: The experiments in this study were designed to follow the time course of nitric oxide (NO) synthesis in the large bowel during acute mechanical ileus. MATERIAL AND METHODS: Occlusion of the mid-transverse colon was maintained for 420 min in anesthetized dogs. Strain-gauge transducers were used to analyze motility changes on the hepatic and lienal flexures, respectively. Constitutive NO synthase (cNOS) and inducible NOS (iNOS) activities were determined in tissue biopsies, and plasma nitrite/nitrate (NOx) level was measured in the portal blood. Following completion of the baseline studies, the animals were treated with either 7-nitroindazole (7-NI, selective neuronal NOS inhibitor), or N-nitro-L-arginine (NNA, non-selective NOS inhibitor). RESULTS: In the sham-operated group the cNOS activities differed significantly in the oral and aboral tissue samples (oral: 102.9; versus aboral: 62.1 fmol/mg protein/min). The obstruction elicited a significant increase in portal NOx and elevated tissue inducible NO synthase (iNOS) activity. NNA treatment decreased the motility index in both intestinal segments for 60 min, but 120 min later the motility index was significantly elevated (2.5-fold increase in the oral part, and 1.8-fold enhancement in the aboral segment, respectively). Treatment with 7-NI decreased the cNOS activity in the oral and aboral parts by approximately 40% and 70%, respectively, and suppressed the motility increase in the aboral colon segment. CONCLUSIONS: The motility of the colon was either significantly increased or decreased, depending on the type and selectivity of the NOS inhibitor compounds applied. NO of neuronal origin is a transmitter that stimulates peristaltic activity; but an increased iNOS/nNOS ratio significantly moderates the obstruction-induced motility increase.

Animals↗

PubMed2005

[Clinical significance of subchorionic and retroplacental hematomas detected in the first trimester of pregnancy].

AIMS: To evaluate the long-term clinical significance of intrauterine hematomas detected in the first trimester of pregnancy in a general obstetric population. METHODS: A prospective study was designed to compare the perinatal outcome in 187 pregnant women with intrauterine hematomas to 6488 controls in which hematomas were not detected at first trimester by ultrasound examination. RESULTS: The incidence of intrauterine hematoma in the first trimester in a general obstetric population was 3.1%. A retroplacental position of the hematoma was significantly correlated with an increased risk for adverse maternal and neonatal complications. The presence or absence of symptoms of threatened abortion did not affect these outcomes. The rates of operative vaginal delivery (RR: 1.9; CI: 1.1-3.2) and cesarean section (RR: 1.4; CI: 1.1-1.8) were significantly greater in the hematoma group as compared to the control group, as well as the rates of pregnancy induced hypertension (RR: 2.1; CI: 1.5-2.9) and preeclampsia (RR: 4.0; CI: 2.4-6.7). Placental abruption (RR: 5.6; CI: 2.8-11.1), and the incidence of placental separation abnormalities was also significantly more frequent in the hematoma group (RR: 3.2; CI: 2.2-4.7). Perinatal complications, including the rate of preterm delivery (RR: 2.3; CI: 1.6-3.2), intrauterine growth restriction (RR: 2.4; CI: 1.4-4.1), fetal distress (RR: 2.6; CI: 1.9-3.5), meconium stained amniotic fluid (RR: 2.2; CI: 1.7-2.9), and NICU admission (RR: 5.6; CI: 4.1-7.6) were also significantly increased in this group. Furthermore, the frequency of intrauterine demise and perinatal mortality was increased in the hematoma group, but this difference did not reach statistical significance (p = 0.6 and p = 0.2). CONCLUSION: The authors' study suggests that the presence of an intrauterine hematoma during the first trimester may identify a population of patients at increased risk for adverse pregnancy outcome.

Adult↗

PubMed2005

[Dual effects of nitric oxide in acute colon obstruction].

UNLABELLED: Nitric oxide (NO) plays central role in the pathophysiology of large bowel diseases. In the gastrointestinal tract the predominant form of nitric oxide synthase (NOS) isoenzymes is neuronal NOS (nNOS). The aims were to investigate the role of NO and the activation of NOS isoforms during acute colonic obstruction. Haemodynamic changes, large bowel motility and plasma levels of nitrate-nitrite (NOx) were observed for 7 hrs in anaesthetized dogs. Group 1 (n=6) served as sham-operated control. In groups 2 (n=8), 3 (n=6), and 4 (n=6) colon obstruction was initiated. Groups 3 and 4 were treated with non-selective NOS inhibitor N-nitro-L-arginine (NNA, 4 mg/kg) or with the selective nNOS inhibitor 7-nitroindazol (7-NI, 5 mg/kg) 3 hr after the obstruction. At the end of the experiments, tissue biopsies were taken from the oral and aboral parts of the colon to determine the constitutive and inducible NOS (cNOS and iNOS, respectively) activities. RESULTS: The cNOS activity of the colon was significantly higher orally then aborally in each group. After obstruction the characteristic features of hyperdynamic sepsis were observed. The obstruction caused significant increase in iNOS activity, which was significantly reduced by the NOS inhibitors. The obstruction increased the motility on both parts of the colon. The administration of NNA transiently inhibited, but later significantly increased the motility of the colon segments. Inhibition of nNOS by 7-NI treatment did not influence the hemodynamic parameters but decreased the motility. CONCLUSION: Neuronal NO increases colon motility at the early stage of large bowel obstruction, however, during a concomitant sepsis the excess of inducible NO will moderate this effect.

Acute Disease↗

PubMed2003

Clinical significance of subchorionic and retroplacental hematomas detected in the first trimester of pregnancy.

OBJECTIVE: To evaluate the long-term clinical significance of intrauterine hematomas detected in the first trimester of pregnancy in a general obstetric population. METHODS: A prospective study was designed to compare perinatal outcomes in 187 pregnant women with intrauterine hematomas and 6488 controls in whom hematomas were not detected at first-trimester ultrasonographic examination. RESULTS: The incidence of intrauterine hematoma in the first trimester in a general obstetric population was 3.1%. A retroplacental position of the hematoma was significantly correlated with an increased risk for adverse maternal and neonatal complications. The presence or absence of symptoms of threatened abortion did not affect these outcomes. The rates of operative vaginal delivery (relative risk [RR] 1.9; confidence interval [CI] 1.1, 3.2) and cesarean delivery (RR 1.4; CI 1.1, 1.8), as well as the rates of pregnancy-induced hypertension (RR 2.1; CI 1.5, 2.9) and preeclampsia (RR 4.0; CI 2.4, 6.7), were significantly greater in the hematoma group. Placental abruption (RR 5.6; CI 2.8, 11.1) and placental separation abnormalities (RR 3.2; CI 2.2, 4.7) were also significantly more frequent in the hematoma group. Perinatal complications, including the rate of preterm delivery (RR 2.3; CI 1.6, 3.2), fetal growth restriction (RR 2.4; CI 1.4, 4.1), fetal distress (RR 2.6; CI 1.9, 3.5), meconium-stained amniotic fluid (RR 2.2; CI 1.7, 2.9), and neonatal intensive care unit admission (RR 5.6; CI 4.1, 7.6), were also significantly increased in this group. Furthermore, the frequency of intrauterine demise and perinatal mortality was increased in the hematoma group, but this difference did not reach statistical significance (Ps =.6 and.2). CONCLUSION: Our study suggests that the presence of an intrauterine hematoma during the first trimester may identify a population of patients at increased risk for adverse pregnancy outcome.

Abortion, Spontaneous↗

PubMed2002

[Delayed interval delivery in multiple pregnancy--case report and review of the literature].

INTRODUCTION: The incidence of multiple pregnancies is increasing with concomitant increased risk in maternal and fetal complications. Premature rupture of membranes and consecutive premature delivery, especially that of immature babies with very low birth weight is accompanied by a high rate of perinatal morbidity and mortality. OBJECTIVES: This is a case report of a mother with twin pregnancy, who aborted the first fetus at 17 weeks and successfully delivered the second one at 29 weeks of gestation with an interval of 84 days following conservative treatment. METHODS: Review of the literature reports the possibilities of the management of delayed interval delivery. RESULTS: The authors conclude that by the use of tocolysis, antepartum steroid-, and antibiotic prophylaxis the life-expectancy of the retained fetus can be improved. CONCLUSION: After the birth of the first fetus delayed delivery in multiple pregnancies can be successful in selected cases. They advocate it only in well prepared perinatal centers for physically and psychologically balanced patients, who are well informed about the risks and benefits of this trial.

Adult↗