PubMed Health⌕ Search

Biomedical subjects

M Mazor

Publications and source records attributed to M Mazor.

At least 55 records · Page 3Linked to original sources
PubMed1990

Changes in amniotic fluid concentrations of prostaglandins E2 and F2 alpha in women with preterm labor.

There is a paucity of data regarding the concentration of prostaglandins (PGs) in the amniotic fluid of women with preterm labor. The purpose of this study was to determine if preterm labor is associated with changes in amniotic fluid concentration of prostaglandins E2 and F2 alpha. Amniotic fluid was retrieved by transabdominal amniocentesis from women with preterm labor and intact membranes. Patients were classified into three groups according to the response to tocolysis and the presence or absence of intra-amniotic infection. PGE2 and PGF2 alpha were measured using specific and sensitive RIA kits. Amniotic fluid concentrations of PGE2 and PGF2 alpha were significantly higher in women with preterm labor and intra-amniotic infection than in women without infection, regardless of the response to tocolysis. These data suggest that both PGs are involved in the mechanism of preterm labor and may have prognostic value.

Amniotic Fluid↗
PubMed1989

Infection and labor. III. Interleukin-1: a signal for the onset of parturition.

The regulatory signals responsible for the increased biosynthesis of prostaglandins during parturition have not been established. Because interleukin-1 is capable of stimulating prostaglandin production by intrauterine tissues and is an inflammatory mediator, we propose that interleukin-1 may act as a signal for the onset of human labor in the setting of intrauterine infection. The purpose of these studies was to determine interleukin-1 activity in amniotic fluid and to establish its relationship with the onset of term and preterm labor. Amniotic fluid from 182 patients was assayed for interleukin-1 activity. Cell-associated interleukin-1 activity was detected in fluid obtained in the third trimester but not in fluid obtained in the second trimester of pregnancy, suggesting a maturational event in interleukin-1 production. The factor responsible for interleukin-1 activity had biochemical characteristics of interleukin-1 alpha (estimated molecular weight of 14 kilodaltons, isoelectric point = 4.9), and its activity was blocked with an anti-interleukin-1 alpha antisera. Women in spontaneous labor at term were likely to have fluid phase interleukin-1 activity in amniotic fluid than women who were not in labor at term. Preterm labor in the setting of intraamniotic infections was associated with significant interleukin-1 activity in amniotic fluid. This bioactivity was predominantly attributable to interleukin-1 beta. A strong correlation between interleukin-1 and amniotic fluid concentrations of prostaglandin E2 and prostaglandin F2 alpha was found in women in preterm labor. These findings support the hypothesis that interleukin-1 may play a role in the initiation of preterm labor associated with intraamniotic infection.

Amniotic Fluid↗
PubMed1989

Infection and labor. V. Prevalence, microbiology, and clinical significance of intraamniotic infection in women with preterm labor and intact membranes.

Amniotic fluid was retrieved by amniocentesis from 264 patients with preterm labor and intact membranes admitted to Yale-New Haven Hospital from Jan. 1, 1985, to July 31, 1988. The prevalence of a positive amniotic fluid culture was 9.1% (24/264). A total of 111 patients (42%) delivered preterm neonates, and 24 (21.6%) of those had positive amniotic fluid cultures. The diagnostic indexes of the Gram stain of amniotic fluid in the prediction of a positive amniotic fluid culture were as follows: sensitivity, 79.1%; specificity, 99.6%; positive predictive value, 95%; and negative predictive value, 98%. Endotoxin was detected with the limulus amebocyte lysate assay in 4.9% (13/264) of patients with preterm labor. All patients with endotoxin in the amniotic fluid delivered preterm neonates. The three most frequently isolated organisms were Ureaplasma urealyticum (n = 6), Fusobacterium species (n = 5), and Mycoplasma hominis (n = 4). Clinical chorioamnionitis was present in only 12.5% of the patients with positive amniotic fluid cultures. Women with positive amniotic fluid cultures had lower gestational ages and more advanced cervical dilatation on admission than women with negative cultures. Preterm infants born to mothers with positive amniotic fluid cultures had a higher incidence of respiratory distress syndrome and infectious complications than preterm neonates born after negative amniotic fluid cultures. These data underscore the frequency and importance of intraamniotic infections in women with preterm labor.

Amniocentesis↗
PubMed1989

Amniotic fluid concentrations of prostaglandin F2 alpha, 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) and 11-deoxy-13,14-dihydro-15-keto-11, 16-cyclo-prostaglandin E2 (PGEM-LL) in preterm labor.

Although prostaglandins (PGs) are considered the key mediators of human parturition at term, there is a paucity of data regarding their participation in the mechanisms responsible for preterm labor. The purpose of this study was to establish if preterm labor is associated with changes in the amniotic fluid concentrations of prostaglandins. PGF2 alpha, 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) and 11-deoxy-13,14-dihydro-15-keto-11,16-cyclo-prostaglandin E2 (PGEM-ll) were measured by using specific and sensitive radioimmunoassays. Amniotic fluid was retrieved by transabdominal amniocentesis from 55 women with preterm labor and intact membranes. Patients were divided into three groups according to the response to tocolysis and the presence or absence of an intra-amniotic infection. Amniotic fluid concentrations of PGFM and PGEM-ll were significantly greater in women with preterm labor and intra-amniotic infection than in women without infection. In addition, patients unresponsive to tocolysis without intra-amniotic infection also had a significantly greater concentration of PGFM and PGEM-ll in amniotic fluid than those responsive to tocolysis. Amniotic fluid concentrations of PGF2 alpha were greater in women with intra-amniotic infection than in women without intra-amniotic infection. In the absence of intra-amniotic infection, no difference in amniotic fluid PGF2 alpha concentrations could be found between women who responded to tocolytic treatment and those who did not.

Amnion↗
PubMed1989

Amniotic fluid arachidonate lipoxygenase metabolites in preterm labor.

This study was conducted to determine if preterm labor with intact membranes is associated with changes in the amniotic fluid concentrations of arachidonate lipoxygenase metabolites. Amniotic fluid was obtained by transabdominal amniocentesis from 68 women with preterm labor. The patients were classified into three groups according to their response to tocolysis and their amniotic fluid culture results: Group 1 - women with a negative amniotic fluid culture who responded to tocolysis (n = 32); Group 2 - women with a negative culture, but who failed to respond to tocolysis (n = 22); and Group 3 - women with intraamniotic infection (n = 14). The following arachidonate lipoxygenase products were measured by radioimmunoassay: leukotriene B4 (LTB4); leukotriene C4 (LTC4); 12-hydroxyeicosatetraenoic acid (12-HETE); and 15-hydroxyeicosatetraenoic acid (15-HETE). The median concentrations of LTB4 were significantly different among the three study groups (26 pg/ml, 67 pg/ml and 885 pg/ml, respectively, p greater than 0.05). Amniotic fluid concentrations of 12-HETE and LTC4 did not vary among the three study groups. On the other hand, a significant difference in the distribution of amniotic fluid concentrations of 15-HETE was noted only between women with intraamniotic infection (Group 3) and women responding to tocolysis (Group 1). These results indicate that the arachidonate lipoxygenase pathway is activated during the course of preterm labor. Selective changes in the concentrations of the assayed metabolites were noted. Amniotic fluid LTB4 concentrations may be a marker for the patient with preterm labor who is unresponsive to tocolysis.

Amniocentesis↗
PubMed1989

Bacterial endotoxin and tumor necrosis factor stimulate prostaglandin production by human decidua.

The purpose of these studies was to determine the effect of bacterial endotoxin and tumor necrosis factor (TNF) on prostaglandin (PG) secretion by human decidua. Decidual explants were established from women undergoing elective cesarean sections before the onset of labor. Escherichia Coli endotoxin and purified human recombinant TNF (rh TNF) were incubated with decidual explants. PGF2 alpha and PGE2 biosynthesis was measured by radioimmunoassay. A significant increase in the release of all PGs into the media occurred in response to LPS and TNF. In the setting of an extraamniotic infection, bacterial and host secretory products (TNF) could trigger the onset of labor, activating the decidua to produce PGs.

Decidua↗
PubMed1989

Amniotic fluid concentration of 5-hydroxyeicosatetraenoic acid is increased in human parturition at term.

5-hydroxyeicosatetraenoic acid (5-HETE) is an arachidonate lipoxygenase product capable of stimulating uterine contractility in a dose-dependent manner in vitro. The purpose of this study was to determine if spontaneous human labor at term is associated with changes in the concentration of this metabolite in amniotic fluid. Fluid was retrieved from 36 women not in labor and from 30 women in active labor at term. 5-HETE was determined by radioimmunoassay. The median amniotic fluid concentration of 5-HETE of women in labor was significantly greater than that of women not in labor (3538 pg/ml vs. 1977 pg/ml, respectively; p = 0.05). This observation is consistent with activation of the lipoxygenase pathway of arachidonic acid metabolism during spontaneous human parturition at term.

Amniotic Fluid↗
PubMed1989

Clinical significance, prevalence, and natural history of thrombocytopenia in pregnancy-induced hypertension.

The purpose of this study was to establish the prevalence and clinical significance of thrombocytopenia in pregnancy-induced hypertension (PIH). Thrombocytopenia, defined as a platelet count less than 100,000/mm3 was found in 11.6% of all patients with PIH. Logistic regression analysis was used to assess the relative contribution of thrombocytopenia, proteinuria, and the degree of hypertension to maternal and perinatal outcome. Thrombocytopenia was the principal contributor to the occurrence of abdominal pain, liver dysfunction, the presence of schistocytes in the peripheral smear, proteinuria, fetal distress, and the requirement for blood transfusions. Thrombocytopenia was also associated with a higher incidence of preterm delivery and intrauterine growth retardation. The nadir platelet count occurred within 48 hours of delivery in 56.7% (21 of 37) of cases. The median number of days for recovery of the thrombocytopenia was 2.0 days (range, 0 to 8 days). In five patients thrombocytopenia preceded the clinical manifestations of PIH. We conclude that thrombocytopenia is an independent and important risk factor for the occurrence of maternal and perinatal complications in PIH.

Abdomen↗
PubMed1989

Is genital colonization with Mycoplasma hominis or Ureaplasma urealyticum associated with prematurity/low birth weight?

Mycoplasma species have been implicated in the pathogenesis of prematurity, intrauterine growth retardation, low birth weight (LBW), and preterm premature rupture of membranes. The purpose of this study was to review the available literature to determine whether there is an association between genital colonization with Mycoplasma hominis or Ureaplasma urealyticum and prematurity/LBW. Twelve studies were reviewed: nine cohort studies, two case-control studies, and one randomized clinical trial of treatment. The overall isolation rate of M hominis from the genital tract was 27.2%, whereas that of U urealyticum was 70.4% (cohort studies). Results from the randomized clinical trial showed that treatment did not alter the rate of prematurity in women carrying mycoplasma species in the genital tract. None of the cohort studies supported an association between genital colonization with U urealyticum and prematurity/LBW. Similarly, no association between M hominis and prematurity/LBW could be demonstrated in seven of the eight and in six of the eight cohort studies, respectively. On the other hand, two case-control studies showed an association between U urealyticum colonization and prematurity without an association with M hominis. We conclude that the weight of the evidence does not support an association between genital colonization with mycoplasma species and prematurity/LBW.

Cohort Studies↗
PubMed1989

Is there an association between colonization with group B Streptococcus and prematurity?

The purpose of this study was to determine whether there is a relationship between colonization of the genitourinary tract with group B Streptococcus (GBS) and prematurity. A search of the literature was conducted to identify articles addressing this issue. Ten studies provided enough data for a critical review; seven studies focused on genital colonization and three on asymptomatic bacteriuria. An association between cervicovaginal colonization with GBS and prematurity could not be demonstrated in six of the seven studies. However, women with asymptomatic bacteriuria caused by GBS had a higher rate of prematurity than did women without asymptomatic bacteriuria. We conclude that the weight of the available evidence does not support an association between prematurity and GBS colonization of the genital tract in the absence of asymptomatic bacteriuria.

Causality↗
PubMed1989

Meta-analysis of the relationship between asymptomatic bacteriuria and preterm delivery/low birth weight.

The relationship between asymptomatic bacteriuria and prematurity/low birth weight (LBW) is still a controversial issue, despite many studies. Meta-analysis, a research tool designed to analyze and combine the results of previous studies, may resolve this discrepancy among contradictory results of clinical trials. The purpose of this study was to examine the relationship between asymptomatic bacteriuria and preterm delivery/LBW using meta-analysis. Reports from the literature were classified according to study design into cohort or randomized-treatment control trials. Meta-analysis of cohort studies showed that untreated asymptomatic bacteriuria during pregnancy significantly increased rates of LBW and preterm delivery. Nonbacteriuric patients had only about two-thirds the risk (typical relative risk = 0.65; 95% confidence interval 0.57, 0.74) of LBW and half the risk (typical relative risk = 0.50; 95% confidence interval 0.36, 0.70) of preterm delivery of those with untreated asymptomatic bacteriuria. These reduced risks correspond to a 3.4 (confidence interval 1.8, 5.0) percentage-point difference in LBW and a 3.8 (1.1, 6.4) percentage-point difference in preterm delivery. The analysis of randomized clinical trials showed that antibiotic treatment significantly reduced the risk of LBW (typical relative risk = 0.56; 95% confidence interval 0.43, 0.73), with a substantial reduction of 6.4 (confidence interval 3.3, 9.5) percentage points in the rate of LBW. We conclude that clinical and epidemiologic evidence indicates a strong association between untreated asymptomatic bacteriuria and LBW/preterm delivery and that antibiotic treatment is effective in reducing the occurrence of LBW.

Anti-Bacterial Agents↗
PubMed1988

Plasma and urine beta-thromboglobulin in severe preeclampsia.

Beta-thromboglobulin (BTG) has been shown to be a specific platelet protein and can be used as a marker of platelet activation in preeclampsia. Concomitant studies of BTG levels in plasma and urine were performed with eight primiparous severe preeclamptic patients and eight normal primiparous women matched for age. The mean plasma BTG in the severe preeclamptic patients was 186.62 +/- 29.93 ng/ml, and in the control group 45.38 +/- 31.84 ng/ml. The P-value for the difference was highly significant (P = 0.000). In contrast, the mean urine BTG in the study group was 8.42 +/- 4.61 ng/ml, while the mean value for the control group was similar, 5.00 +/- 3.20 ng/ml. The P-value for the difference was not significant (0.05 less than P less than 0.10). These results show that urinary BTG cannot be considered an indicator of platelet activation in severe preeclampsia. A low urinary BTG concentration in the presence of high plasma BTG levels may rather express renal impairment. Failure of BTG renal clearance would contribute to further raising the level of plasma BTG.

Adult↗
PubMed1988

The value and limitations of the Gram stain examination in the diagnosis of intraamniotic infection.

Gram stain examination of amniotic fluid is a method used for the rapid diagnosis of intraamniotic infection in patients with preterm premature rupture of membranes and preterm labor. The management of these patients relies heavily on the Gram stain results. Therefore, it is critical that the diagnostic value and limitations, optimal technique, and outcome correlates be precisely established. Most studies have focused on culture results rather than on Gram stain results to describe neonatal and maternal outcome. However, management is based on the Gram stain because culture results are not immediately available. One hundred eighty-seven amniocenteses were performed in 131 patients with preterm premature rupture of the membranes (n = 90) and preterm labor (n = 41). Spun and unspun Gram stains were performed. Centrifugation of the sample did not improve the sensitivity of the technique significantly. The agreement between the two methods was substantial (kappa index 0.89, p less than 0.001). The sensitivity of the Gram stain was 44.8% and the specificity was 97.6%. The sensitivity of the Gram stain was directly proportional to the number of bacteria present in amniotic fluid. In the presence of greater than 10(5) colony forming units per milliliter, 80% of the Gram stains were positive. The absence of both bacteria and white blood cells in a smear was associated with a negative culture of amniotic fluid in 95% of the cases. Clinical chorioamnionitis was associated with a positive Gram stain of amniotic fluid (p less than 0.001). There was a trend toward a higher incidence of endometritis in patients with a positive Gram stain compared with those with a negative Gram stain (p = 0.07). There was no neonatal infectious morbidity in patients with a true negative Gram stain. Patients with a false negative Gram stain had a 25% incidence of neonatal infectious complications (proved and suspected sepsis).

Adult↗
PubMed1988

Plasma antithrombin III levels in pre-eclampsia and chronic hypertension.

Plasma levels of antithrombin III were tested during pregnancy in a control group of normal patients and in a study group that included patients with moderate and severe pre-eclampsia and chronic hypertension. The control group showed mean antithrombin III activity of 97.9 +/- 20.9%, the severe pre-eclamptic patients 22.33 +/- 18.22%, the moderate pre-eclamptic patients 56.0 +/- 7.56%, and the chronic hypertensive patients 77.5 +/- 6.69%. The difference between normal pregnancy and moderate pre-eclampsia was significant at P less than 0.002, normal pregnancy and severe pre-eclampsia P less than 0.002, moderate and severe pre-eclampsia P less than 0.002, chronic hypertension and normal pregnancy P less than 0.1, and chronic hypertension and severe pre-eclampsia P less than 0.002. All the severe pre-eclamptic patients and 2 out of 6 of the moderate pre-eclamptic women were below 55.7% (mean - 2S.D.) of normal antithrombin III activity. Patients with heavy proteinuria had depressed antithrombin III activity. However, chronic hypertensive pregnancies, although rather a small group, had almost normal values of plasma antithrombin III activity. The plasma antithrombin III value may thus help to distinguish between chronic hypertension and severe pre-eclamptic disease.

Adult↗