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Biomedical subjects

M Mazor

Publications and source records attributed to M Mazor.

At least 199 records · Page 11Linked to original sources
PubMed1992

The relationship between acute inflammatory lesions of the preterm placenta and amniotic fluid microbiology.

OBJECTIVE: Our objective was to determine the relationship between microbial invasion of the amniotic cavity and the presence and severity of acute inflammatory lesions in the placenta. STUDY DESIGN: Placental histologic and amniotic fluid microbiologic studies were performed in 92 consecutive patients who were admitted with preterm labor and intact membranes and delivered within 48 hours after amniocentesis. RESULTS: The prevalence of a positive amniotic fluid culture was 38% (35 of 92). There was a strong association between the presence and severity of inflammation in the amnion, chorion-decidua, umbilical cord, and chorionic plate and the results of the amniotic fluid culture (p less than 0.0001 for each tissue section). Three patterns of inflammation of the chorion-decidua were identified: marginating, nonmarginating, and a mixed pattern. The marginating and the mixed patterns of inflammation were strongly associated with the presence of a positive amniotic fluid culture. Acute inflammation of the chorionic plate was the most sensitive indicator of a microbial invasion of the amniotic cavity (sensitivity 96.6%), and funisitis and umbilical vasculitis had the highest specificity (85.7%). CONCLUSION: The presence of acute inflammatory lesions of the chorioamniotic membranes can serve as a marker of microbial invasion of the amniotic cavity.

Amnion↗
PubMed1992

Tumor necrosis factor in preterm and term labor.

OBJECTIVE: Our objective was to determine if labor (term and preterm) and microbial invasion of the amniotic cavity were associated with changes in amniotic fluid concentrations of tumor necrosis factor. STUDY DESIGN: Amniotic fluid was retrieved by transabdominal amniocentesis from 269 women in the following groups: midtrimester (n = 38), preterm labor with intact membranes (n = 52), preterm premature rupture of membranes (n = 74), term in active labor (n = 84), and term not in labor (n = 21). Fluid was cultured for aerobic and anaerobic bacteria and for Mycoplasma species. Tumor necrosis factor was measured with a commercially available enzyme-linked immunosorbent assay validated for amniotic fluid (sensitivity 60 pg/ml). RESULTS: Amniotic fluid from pregnant women in the second and third trimesters who were not in labor did not contain tumor necrosis factor. Among women in preterm labor, 92.3% (12/13) of patients with a positive amniotic fluid culture had detectable tumor necrosis factor in the amniotic fluid (median 820 pg/ml, range less than 60 to 2340 pg/ml). In contrast, only 10.2% (4/39) of women with a negative amniotic fluid culture had detectable tumor necrosis factor. Histopathologic chorioamnionitis was found in all patients who had a positive amniotic fluid culture, and tumor necrosis factor was detectable in the amniotic fluid of all but one of these patients. Among women in active labor at term, 25% (21/84) had detectable tumor necrosis factor in the amniotic fluid. Tumor necrosis factor was detected more frequently in the amniotic fluid of patients with a positive amniotic fluid culture than in patients with a negative culture (46.6% [7/15] vs 20.2% [14/69], p = 0.047). Amniotic fluid concentrations of tumor necrosis factor were significantly higher in patients with preterm premature rupture of membranes, labor, and a positive amniotic fluid culture than in the other subgroups of patients with preterm premature rupture of membranes. CONCLUSION: Parturition in the setting of microbial invasion of the amniotic cavity is associated with activation of the cytokine network as demonstrated by the detection of tumor necrosis factor in human amniotic fluid.

Adult↗
PubMed1992

Eradication of Ureaplasma urealyticum from the amniotic fluid with transplacental antibiotic treatment.

Ureaplasma urealyticum was isolated from the amniotic fluid of a patient with preterm premature rupture of membranes at 24 weeks. A second amniocentesis performed 48 hours later indicated an increase in the number of neutrophils in the amniotic fluid. Treatment with erythromycin, ampicillin, gentamicin, and clindamycin was instituted for a period of 6 days. Amniotic fluid analysis from a third amniocentesis performed 24 hours after discontinuation of antibiotic treatment revealed only a few white blood cells and was negative for microorganisms. The pregnancy continued for 22 days after admission, at which time spontaneous labor began. The neonate survived with no sequelae and had negative blood cultures. Antibiotic treatment was associated with eradication of Ureaplasma urealyticum from the amniotic cavity, pregnancy prolongation, and neonatal survival.

Adult↗
PubMed1992

Infection and labor. VII. Microbial invasion of the amniotic cavity in spontaneous rupture of membranes at term.

OBJECTIVE: The purpose of this study was to determine the frequency, microbiologic characteristics, and clinical significance of microbial invasion of the amniotic cavity in women with premature rupture of membranes at term. STUDY DESIGN: Amniocentesis was performed in 32 women with term premature rupture of membranes and amniotic fluid cultured for aerobic and anaerobic bacteria and Mycoplasmas. RESULTS: The prevalence of positive amniotic fluid cultures was 34.3% (11/32). The most common isolates were Ureaplasma urealyticum, Peptostreptococcus sp., Lactobacillus sp., Bacteroides fragilis, and Fusobacterium sp. Clinical chorioamnionitis occurred only in one patient with a positive amniotic fluid culture. Her neonate had ophthalmitis. Three patients (9.4%) had endometritis. Among women who were delivered vaginally, those with a positive amniotic fluid culture had a significantly higher rate of endometritis than those with a negative culture (33% [3/9] vs 0% [0/20], respectively, p = 0.023). CONCLUSIONS: These data indicate that microbial invasion of the amniotic cavity occurs in approximately one third of patients with preterm premature rupture of membranes. Microbial invasion of the amniotic cavity is a risk factor for endometritis in women with term premature rupture of membranes.

Amnion↗
PubMed1992

The natural interleukin-1 receptor antagonist in term and preterm parturition.

OBJECTIVE: Interleukin-1 has been implicated in the mechanisms responsible for preterm labor in the setting of infection. The interleukin-1 receptor antagonist is a new member of the interleukin-1 gene family that inhibits the biologic effects of interleukin-1 by blocking its receptors. Reduction of interleukin-1-induced prostaglandin production by intrauterine tissues may have potential value in the treatment of preterm labor associated with infection. The purpose of these studies was (1) to determine interleukin-1 receptor antagonist levels in the amniotic fluid of women with term and preterm labor (with and without infection) and (2) to study the effects of interleukin-1 receptor antagonist on interleukin-1-induced prostaglandin biosynthesis by human amnion and chorion. STUDY DESIGN: Amniotic fluid was obtained from women in the midtrimester of pregnancy (n = 20), at term pregnancy (with and without labor, n = 69), and in preterm labor (n = 47). Fluid was cultured for aerobic and anaerobic bacteria and Mycoplasmas. Interleukin-1 alpha, interleukin-1 beta, and interleukin-1 receptor antagonist concentrations were measured by immunoassays previously validated for human amniotic fluid. The effect of interleukin-1 receptor antagonist on interleukin-1-induced prostaglandin production by amnion and chorion was studied with primary cultures. Cells were incubated with interleukin-1 receptor antagonist and interleukin-1 alpha or interleukin-1 beta for 16 hours. Prostaglandin E2 released into the media was assayed by immunoassay. RESULTS: (1) Interleukin-1 receptor antagonist was present in all amniotic fluid samples; (2) amniotic fluid contains the highest interleukin-1 receptor antagonist concentrations detected in any biologic fluid to date; (3) amniotic fluid interleukin-1 receptor antagonist concentrations were not increased in women with preterm labor and intraamniotic infection in spite of dramatically elevated concentrations of interleukin-1 alpha and interleukin-1 beta in the same fluid (median 22 ng/ml and range 0.16 to 70 for preterm labor with negative amniotic fluid culture vs median 30 ng/ml and range 6 to 70 for preterm labor with positive amniotic fluid culture; p > 0.05); (4) interleukin-1 receptor antagonist reduced interleukin-1 beta-induced prostaglandin E2 production by amnion and chorion in a dose-dependent manner; (5) interleukin-1 receptor antagonist by itself did not stimulate prostaglandin E2 release by amnion and chorion when used in concentrations ranging from 0.1 to 1000 ng/ml. CONCLUSIONS: (1) Interleukin-1 receptor antagonist is a physiologic component of amniotic fluid; (2) the release of interleukin-1 alpha and interleukin-1 beta into the amniotic fluid in women with preterm labor is not associated with an increase in interleukin-1 receptor antagonist levels in amniotic fluid; (3) interleukin-1 receptor antagonist reduces interleukin-1-induced prostaglandin production by amnion and chorion; (4) exogenous anticytokine agents may be of value in the treatment of preterm labor.

Adult↗
PubMed1992

Infection and labor. VIII. Microbial invasion of the amniotic cavity in patients with suspected cervical incompetence: prevalence and clinical significance.

OBJECTIVE: The purpose of this study was to determine the prevalence and clinical significance of microbial invasion of the amniotic cavity in patients presenting with cervical dilatation in the midtrimester of pregnancy. STUDY DESIGN: Amniocentesis for microbial studies was performed in women admitted with cervical dilatation > or = 2 cm, intact membranes, and without active labor between 14 and 24 weeks of gestation. Amniotic fluid was cultured for aerobic and anaerobic bacteria, as well as for mycoplasmas. Gram stain was performed on all samples. RESULTS: The prevalence of microbial invasion of the amniotic cavity was 51.5% (17/33). The most common microbial isolates were Ureaplasma urealyticum, Gardnerella vaginalis, Candida albicans, and Fusobacterium sp. All patients with microbial invasion of the amniotic cavity had complications. Patients who underwent cervical cerclage in the presence of a positive amniotic fluid culture had rupture of membranes, clinical chorioamnionitis, or pregnancy loss. On the other hand, the prognosis of patients with a negative amniotic fluid culture was better than that of patients with a positive culture. Of 16 patients with a negative amniotic culture, nine were delivered at > 34 weeks. CONCLUSIONS: (1) Microbial invasion of the amniotic cavity occurs frequently in women presenting with cervical dilatation in the midtrimester; (2) the microbiologic state of the amniotic cavity is an important prognostic factor for pregnancy outcome; (3) amniocentesis to determine the microbiologic characteristics of the amniotic cavity should be considered before a cerclage is placed in women presenting with cervical dilatation in the midtrimester.

Abortion, Spontaneous↗
PubMed1991

[Complications of third stage labor and the puerperium in preterm and term deliveries].

Preterm delivery is the leading cause of perinatal morbidity and mortality worldwide. The purpose of the present study was to determine whether preterm delivery is associated with complications of the third stage of labor and of the puerperium. Retained placentas occurred more frequently in 99 women with preterm vaginal delivery than in 97 with term vaginal delivery (13.1% vs 1%, p = 0.003). There was a higher rate of endometritis in women delivering before term than in those delivering at term (10.1% vs 0%, p = 0.004). This study indicated that preterm labor and delivery is associated with higher rates of perinatal morbidity and mortality and with an increased risk of maternal complications.

Female↗
PubMed1991

Human decidua: a source of cachectin-tumor necrosis factor.

Cachectin-tumor necrosis factor (TNF-alpha) has been implicated as a possible signal for the initiation of human parturition in the setting of infection. These studies were conducted to determine whether human decidua can produce TNF-alpha in response to bacterial lipopolysaccharide (LPS). Decidual explants from women undergoing elective cesarean sections were incubated with and without Escherichia coli LPS (25 ng/ml) for 20 h. TNF-alpha concentration in the conditioned media was measured with an enzyme-linked immunoassay and bioassay (L929 bioassay). While conditioned media from unstimulated decidual explants contained either undetectable or low levels of TNF-alpha, conditioned media from LPS stimulated decidua contained TNF-alpha (mean = 2.6 pmol/mg protein per 20 hours, SEM +/- 1.03). There was a strong correlation between the immunoreactive and bioactive TNF-alpha (Spearman rank correlation r = 0.76, P less than 0.001). We conclude that human decidua in vitro can produce TNF-alpha in response to LPS.

Decidua↗
PubMed1991

[Fetal heart rate monitoring in ambulatory and resting mothers].

The nonstress test (NST) to assess fetal wellbeing is done over the course of 30 minutes with the patient lying in the semi-Fowler position. The test relates changes in fetal heart rate to fetal movement, and uterine contractions are also recorded. The purpose of this study was to determine whether the NST is affected by maternal ambulation, so that the patient must be lying down when it is performed. We did the NST during ambulation as well as with the patient reclining. There were no differences in fetal heart rate and/or uterine activity between the 2 tests. 50% of the women preferred the ambulatory method while 25% preferred reclining and 25% expressed no preference. We conclude, that the ambulatory NST is an acceptable alternative to the conventional test with the patient reclining.

Female↗
PubMed1991

Neutrophil attractant/activating peptide-1/interleukin-8 in term and preterm parturition.

The neutrophil is the leukocyte most frequently recruited into the amniotic fluid in cases of microbial invasion of the amniotic cavity. Neutrophil attractant/activating peptide-1/interleukin-8 is a newly identified cytokine that is capable of inducing selective neutrophil chemotaxis and activation. The purpose of this study was to examine the relationship between amniotic fluid concentrations of neutrophil attractant/activating peptide-1/interleukin-8, microbial invasion of the amniotic cavity, and parturition (term and preterm). Amniotic fluid neutrophil attractant/activating peptide-1/interleukin-8 was measured with an immunoassay validated for human amniotic fluid (sensitivity 0.3 ng/ml). Fluid was obtained from women in the following groups: midtrimester (n = 38), term not in labor (n = 38), term in active labor (n = 67), and preterm labor with intact membranes (n = 62). Fluid was cultured for aerobic and anaerobic bacterial and Mycoplasma. Sterile amniotic fluid from most women in the midtrimester of pregnancy and women at term not in labor did not contain immunoreactive neutrophil attractant/activating peptide-1/interleukin-8. Microbial invasion of the amniotic cavity was associated with increased concentrations of neutrophil attractant/activating peptide-1/interleukin-8. The amniotic fluid of women with preterm labor and sterile amniotic fluid who had preterm delivery contained higher neutrophil attractant/activating peptide-1/interleukin-8 levels than did the amniotic fluid of women who responded to tocolysis and had delivery at term. Term parturition is associated with increased concentrations of neutrophil attractant/activating peptide-1/interleukin-8 in the amniotic fluid. We conclude that neutrophil attractant/activating peptide-1/interleukin-8 is part of the host response to microbial invasion of the amniotic cavity and that increased amniotic fluid availability of this cytokine occurs in term and preterm parturition.

Adult↗
PubMed1991

Amniotic fluid white blood cell count: a rapid and simple test to diagnose microbial invasion of the amniotic cavity and predict preterm delivery.

The purpose of this study was to determine the value of amniotic fluid white blood cell count in the diagnosis of microbial invasion of the amniotic cavity. Amniotic fluid was retrieved by amniocentesis from 195 patients with preterm labor and intact membranes. Fluid was cultured for aerobic and anaerobic bacteria, as well as for mycoplasmas. The prevalence of a positive amniotic fluid culture was 12.8% (25/195). Patients with a positive amniotic fluid culture had a significantly higher median amniotic fluid white blood cell count than did patients with a negative amniotic fluid culture (median, 6 cells/mm3; range, 0 to 11,000 cells/mm3 vs median, 320 cells/mm3; range, 1 to 4480 cells/mm3; p less than 0.0001). An amniotic fluid white blood cell count greater than or equal to 50 cells/mm3 had a sensitivity of 80% (20/25), a specificity of 87.64% (149/170), a positive predictive value of 48.78% (20/41), and a negative predictive value of 96.75% (149/154) in the detection of a positive amniotic fluid culture for microorganisms. Although the sensitivity of an amniotic fluid white blood cell count (greater than or equal to 50 cells/mm3) in the detection of microbial invasion of the amniotic cavity was greater than that of the Gram stain of amniotic fluid (80% [20/25] vs 48% [12/25]; p less than 0.05), the specificity was lower (87.64% [149/170] vs 98.8% [168/170]; p less than 0.05). However, 88% (15/17) of all patients with an amniotic fluid white blood cell count greater than or equal to 50 cells/mm3 and a negative amniotic fluid culture had a spontaneous preterm delivery. We conclude that the amniotic fluid white blood cell count is a sensitive, simple, and inexpensive test for the detection of microbial invasion of the amniotic cavity. An elevated amniotic fluid white blood cell count is a risk factor for preterm delivery.

Adult↗
PubMed1991

Systemic administration of interleukin-1 induces preterm parturition in mice.

Interleukin-1 has been postulated as a signal for the initiation of preterm labor and delivery. Interleukin-1 is produced by human decidua, stimulates prostaglandin production by intrauterine tissues, and is present in the amniotic fluid of women with preterm labor and intraamniotic infection. The purpose of these studies was to determine whether interleukin-1 could induce parturition in an animal species. Timed-pregnant C3H/HeJ inbred mice (n = 24) (genetically endotoxin resistant) were randomized to receive either recombinant human interleukin-1 or sterile phosphate-buffered saline solution between days 15 and 17 of gestation (normal length of pregnancy, 20 to 21 days). Three consecutive subcutaneous injections of interleukin-1 or phosphate-buffered saline solution were administered within 6 hours. Examinations of the animals were performed by blinded observers. Parturition occurred within 24 hours in all of the interleukin-1-treated mice and in none of the control group. Vaginal bleeding was first noted 4 hours after the first interleukin-1 injection, and delivery began within 12 hours after the last interleukin-1 injection. Premature delivery occurred in all interleukin-1-injected mice. Laparotomy revealed that there were no remaining fetuses in utero. All mice in the control group delivered spontaneously between days 20 and 22. We conclude that systemic administration of interleukin-1 induces preterm labor and delivery in mice.

Animals↗