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Biomedical subjects

P Samuels

Publications and source records attributed to P Samuels.

At least 19 recordsLinked to original sources
PubMed2006

Disseminated intravascular coagulation following selective termination in a twin pregnancy. A case report.

OBJECTIVE: Coagulation abnormalities after single fetal demise are well described, but similar cases had not been previously reported following therapeutic selective termination. CASE: A 23-year-old G(3) P(2001) with a monochorionic-diamnionic twin pregnancy underwent selective termination at 20 4/7 weeks for severe twin-twin transfusion syndrome. Her fibrinogen thereafter decreased and she developed disseminated intravascular coagulopathy with pathological bleeding during a cesarean section. The maternal coagulopathy resolved postpartum. CONCLUSION: Coagulation disorders can follow selective termination. Recommendations to serially follow coagulation parameters after these procedures, however, cannot be based upon a single case.

Adult↗
PubMed2000

The effects of repeat doses of antenatal corticosteroids on maternal adrenal function.

OBJECTIVE: The purpose of this study was to determine whether repeated doses of maternal corticosteroids suppress the maternal hypothalamic-pituitary-adrenal axis. STUDY DESIGN: The low-dose corticotropin stimulation test (1.0 microg intravenously) was administered a median of 3 days after the last betamethasone dose to 18 pregnant women who had received at least 2 weekly courses of antenatal betamethasone and to 6 control subjects matched for gestational age who had not received antenatal corticosteroids. RESULTS: The mean basal cortisol level was significantly depressed among women who had received betamethasone with respect to control subjects (1.9 +/- 1.5 vs 26.5 +/- 6.2 microg/dL; P <.001). The maternal cortisol level after corticotropin stimulation was significantly lower in all women who had received betamethasone (P <. 001). The mean time to attainment of peak cortisol level was significantly longer among women who had received betamethasone than among control subjects (37 +/- 6.8 vs 27.4 +/- 1.6 minutes; P <.001). CONCLUSIONS: Repeated courses of betamethasone lead to barely detectable maternal basal cortisol levels and secondary adrenal insufficiency.

Adrenal Cortex Hormones↗
PubMed1999

Prostaglandin E2 cervical ripening without subsequent induction of labor.

OBJECTIVE: To determine whether outpatient administration of intracervical prostaglandin (PG) E2 gel decreases the interval to delivery and duration of labor. METHODS: A randomized, double-blind, placebo-controlled trial compared the intracervical placement of 0.5 mg PGE2 gel with placebo in 61 pregnant women at 38 weeks' or greater gestation with Bishop scores less than 9. Transvaginal cervical length, fetal fibronectin, and Bishop score were assessed before gel placement. Subjects were then allowed to go into spontaneous labor unless an indication for induction developed. RESULTS: Thirty women were assigned to PGE2 and 31 to placebo. There were no significant demographic differences between the groups and there were no differences in cervical length, fetal fibronectin status, or Bishop scores. Fifteen women in the PGE2 group and five in the placebo group went into labor and delivered within the first 2 days after gel placement (P = .007). The median interval to delivery was significantly shorter in the PGE2 group, at 2.5 days, compared with placebo, at 7 days (P = .02). Nulliparas in the PGE2 group had a median interval to delivery of 2 days, compared with 7 days for nulliparas receiving placebo (P = .03). Active phases of labor were significantly shorter in the PGE2 group and for women with a negative fetal fibronectin test who received PGE2. CONCLUSION: Outpatient administration of intracervical PGE2 gel shortened intervals to delivery and shortened labor.

Adult↗
PubMed1999

Fetal scarless wound healing.

Advances in fetal monitoring and open fetal surgery for life-threatening congenital diseases have provided us with the unique opportunity to examine fetal surgical wound healing. Fetal wounds heal rapidly and without scarring. The exact mechanisms of fetal scarless healing remain unknown. This article illustrates the most current understanding of the fetal wound healing process by examining the intrinsic properties of fetal skin, fetal fibroblasts, wound matrix, fetal environment, and various cytokines. In fetal wound, transforming growth factor-beta and hyaluronic acid-rich wound matrix play pivoting roles in scarless repair. Different experimental strategies to manipulate the healing of adult wounds will be presented. These therapeutic measures are based on the scarless fetal wound repair model. We will also briefly comment on the current status of fetal surgery.

Animals↗
PubMed1997

Tumour necrosis factor-alpha induces cyclo-oxygenase-2 gene expression in first trimester trophoblasts: suppression by glucocorticoids and NSAIDs.

Tumour necrosis factor-alpha (TNF-alpha) is a pleiotropic cytokine which stimulates the synthesis and release of prostaglandins (PGs) in several in vitro and in vivo models of preterm labour. While TNF-alpha simulated PG production has been described in decidual, amnion and myometrial cells, to date no studies have focused on the role of TNF-alpha in the stimulation of arachidonic acid metabolism in placental trophoblast cells. Cyclo-oxygenase-2 (COX-2) is the rate-limiting enzyme in PG biosynthesis and is expressed de novo during cellular activation by cytokines. To test whether TNF-alpha alters expression of COX-2, trophoblasts from first trimester chorionic vili were cultured as a continuous cell line and treated with TNF-alpha alone or with TNF-alpha and dexamethasone (Dex). Total RNA and protein were extracted from the trophoblasts and subjected to Northern and immunoblot analysis, respectively. Northern blots were hybridized with a 32P-labelled probe encoding the COX-2 cDNA and immunoblots were incubated with anti-COX-2 antibodies. There was a time- and dose-dependent increase in COX-2 mRNA and protein expression in cells stimulated with TNF-alpha. The effect of TNF-alpha on COX-2 mRNA and protein expression was inhibited by dexamethasone (Dex). To examine the production of PGE2 and PGF(2 alpha), specific RIAs were performed on culture media from similarly stimulated cells. PG accumulation after TNF-alpha stimulation occurred in a time- and dose-dependent fashion with a similar inhibition of PG accumulation after Dex exposure. To be certain that TNF-alpha stimulated PGE2 production was, indeed, a result of COX-2 induction, RIAs were carried out with the COX-2-selective inhibitor NS-398. Cells stimulated with the NS-398 after TNF-alpha exposure demonstrated suppression of TNF-alpha-stimulated PGE2 formation. The results suggest that TNF-alpha elicits part of its pathophysiologic effects in preterm labour via alterations in COX-2 gene expression within the placental microenvironment.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1997

The effect of the source of transfused blood on the rate of consumption of transfused red blood cells in pregnancies affected by red blood cell alloimmunization.

OBJECTIVE: Our purpose was to compare the rate of consumption of maternally donated red blood cells with the rate of red blood cells from volunteers in fetuses affected by red blood cell alloimmunization. STUDY DESIGN: The rate of hemoglobin decline was calculated in 293 fetal transfusions in 52 pregnancies, in 43 patients affected by red blood cell alloimmunization from 1987 to 1996. Fifty-eight transfusions were excluded from analysis. Hemoglobin decline was stratified by gestational age. The rates of consumption were compared with use of unpaired t tests. RESULTS: The rates of hemoglobin decline (in grams per deciliter per day) were 18 to 24 weeks, 0.47 volunteer and 0.38 maternal (p = 0.174); 25 to 28 weeks 0.41 volunteer, 0.34 maternal (p = 0.46); 29 to 32 weeks, 0.35 volunteer, 0.33 maternal; > or = 33 weeks, 0.37 volunteer, 0.25 maternal, p = 0.048). Hemoglobin decline was less for the maternal donation group than for the volunteer donation group throughout gestation, becoming significant only in fetuses at > or = 33 weeks. CONCLUSION: In the red blood cell-alloimmunized fetus, there is less consumption of maternal than of volunteer red blood cells. This difference reaches a statistical significance only in late gestation.

Blood Donors↗
PubMed1997

The seroprevalence of the rubeola antibody in a prenatal screening program.

OBJECTIVE: To evaluate the seroprevalence of the rubeola (measles) antibody in several obstetric populations. METHODS: In this cross-sectional study, women presenting for prenatal care underwent measurement of antibodies to the rubeola virus. The study population presented for care at either an urban medical center (group I) or a suburban medical center (group II). These groups were divided further into those receiving care in a resident-supervised clinic (A) and those in a private-practice setting (B). RESULTS: A total of 768 women were tested. Seventy-five (9.8%) women had rubeola antibody titers less than or equal to 0.13 and were classified as seronegative. The lowest percentage of seronegative women (3.2%) was found at the urban resident-supervised clinic site. The highest percentage of seronegative women (20.5%) was found in the suburban resident-supervised clinic site. Women classified as seronegative were younger, with a mean age of 25.0 years. No significant difference was observed based on gravidity, parity, or care received in an urban versus suburban private-practice setting. CONCLUSION: We suggest that an appreciable number of women presenting for prenatal care may lack antibodies to the rubeola virus. In the interest of personal and public health, populations believed to be at risk may benefit from ongoing surveillance of immune status and appropriate vaccination. Additional study is necessary to define best those groups that would benefit from surveillance and vaccination.

Adult↗
PubMed1996

Perinatal outcome and long-term follow-up associated with modern management of diabetic nephropathy.

OBJECTIVE: To determine outcomes in pregnancies complicated by class F diabetes mellitus cared for at a single center, and to assess renal function in these women. METHODS: A retrospective review (1988-1994) of all pregnant women with class F diabetes was performed, as well as an evaluation of current renal function. RESULTS: Forty-six pregnancies in 45 women reached a mean (+/- standard deviation) gestational age of 35.8 +/- 2.3 weeks, with a mean birth weight of 2623 +/- 818 g. No deliveries occurred before 30 weeks and 39 (84%) were at least 34 weeks. Perinatal survival was 100%. Women with initial serum creatinine exceeding 1.5 mg/dL or more than 3 g/24 hours proteinuria had an increased risk of early delivery, lower birth weight, preeclampsia, and cesarean delivery. Twenty-four individuals (53%) developed preeclampsia and seven met criteria for severe preeclampsia. By the third trimester, 26 women(58%) had greater than a 1 g/24 hour increase in proteinuria and 16 (36%) demonstrated more than a 15% fall in creatinine clearance. Follow-up was obtained in 34 subjects with a mean duration of 2.8 years. Individuals with initial creatinine clearance greater than 90 mL/minute and less than 1 g of protein per 24 hours had less loss of renal function at follow-up, as measured by creatinine clearance. At follow-up, mean protein excretion had decreased 1.9 g/24 hours from third-trimester values, but eight women (24%) maintained protein excretion exceeding 3 g/24 hours. CONCLUSION: Modern management of class F patients can result in good perinatal outcomes. Renal function studies early in pregnancy can be used to define the risk of perinatal morbidity and long-term progression of renal disease.

Adult↗
PubMed1996

Antiplatelet antibody testing in thrombocytopenic pregnant women.

OBJECTIVE: The purpose of the study was to attempt to distinguish pregnant women with gestational thrombocytopenia from those with idiopathic immune thrombocytopenia by eight different platelet antibody assays. STUDY DESIGN: Sera from pregnant women with presumed gestational thrombocytopenia (n = 160) and idiopathic immune thrombocytopenia (n=90) were prospectively tested for indirect and platelet-associated immunoglobulins G and M and complement C3, as well as for serotonin release. After the results were analyzed, a subset of patients were subsequently analyzed for circulating antiplatelet antibody directed against platelet membrane glycoprotein GPIIb/IIIa. RESULTS: Indirect immunoglobulin G was significantly greater in the 85 women with idiopathic immune thrombocytopenia than in the 129 women with gestational thrombocytopenia (p<0.001). Platelet-associated immunoglobulin G was elevated in the majority of women, both those with gestational thrombocytopenia and those with idiopathic immune thrombocytopenia. There were also no statistically significant difference in the values for platelet-associated C3 or indirect immunoglobulin M and C3. Levels of platelet-associated immunoglobulin M showed a tendency to be higher in women with gestational thrombocytopenia (p=0.04), as did the values in the serotonin release assay (p=0.06). CONCLUSION: Our data demonstrate that patients with gestational thrombocytopenia had surprisingly high levels of platelet-associated immunoglobulin despite mild thrombocytopenia. Comparison of a relatively large number of patients with idiopathic immune thrombocytopenia and gestational thrombocytopenia indicates that women with idiopathic immune thrombocytopenia cannot be distinguished from those with gestational thrombocytopenia by means of one or more of the prototypic platelet antiglobulin tests currently in use. Our preliminary data with glycoprotein-specific assays indicate that they may be more useful.

Autoantibodies↗
PubMed1996

Prenatal detection of fetal anomalies in pregnancies complicated by insulin-dependent diabetes mellitus.

OBJECTIVES: We evaluated the clinical utility of a comprehensive program of prenatal diagnostic testing for congenital anomalies in pregnancies complicated by insulin-dependent diabetes mellitus. STUDY DESIGN: Data were retrospectively analyzed from 289 diabetic women and their newborns from August 1987 to July 1993. Our protocol included initial hemoglobin A1 and maternal serum alpha-fetoprotein determinations and comprehensive fetal ultrasonography inclusive of a standard four-chamber view of the heart and detailed multiimage fetal echocardiography. RESULTS: Anomalies were identified in 29 of 289 (10%) fetuses and neonates: 12 cardiac only, 14 noncardiac, and 3 combined. In 21 of the 29 (72%) neonates the anomalies were detected prenatally. Twelve of 15 (80%) cardiac and 10 of 17 (59%) noncardiac lesions were identified prenatally. Cardiac lesions, especially of the cardiac septum and great vessels, accounted for 50% of all fetal defects. Malformations of the neuroaxis, skeleton, and genitourinary system were also detected. There were six neonatal deaths and four therapeutic pregnancy terminations associated with congenital anomalies. Although the hemoglobin A1 level was statistically significantly increased in 22 mothers of anomalous fetuses (p = 0.017), the actual difference between affected and nonaffected pregnancies was not clinically meaningful and much overlap occurred. Although 96% of women with a normal hemoglobin A1 level were delivered of normal infants, only 14% of those with an elevated value had a malformed fetus. Similarly, although 89% of gravid women with a normal maternal serum alpha-fetoprotein level were delivered of nonaffected fetuses, only 7.3% of patients with an elevated value had a malformed fetus. For the detection of cardiac defects, the sensitivity of the four-chamber view compared with detailed multiimage fetal echocardiography was 33% and 92%, respectively. CONCLUSIONS: This study demonstrates the utility of a comprehensive program to detect fetal anomalies in pregnancies complicated by diabetes mellitus.

Congenital Abnormalities↗
PubMed1996

Normal saline i.v. fluid load decreases uterine activity in active labour.

This study was designed to observe the effects of i.v. fluid infusion on uterine activity during normal labour in women receiving an extradural block. Thirty-four women in spontaneous labour at term gestation were allocated randomly and prospectively to one of three i.v. pre-extradural fluid load groups: group A, no fluid load; group B, normal saline 500 ml; and group C, normal saline 1000 ml. Continuous internal measurement of uterine activity was observed before, during and after fluid infusion and extradural block. In groups A and B, uterine activity did not change. In group C, uterine activity decreased after infusion of saline (P < 0.01) and returned to baseline over the next 20 min. Extradural block was not associated with a change in uterine activity. Hypotension was not increased in the group that received no fluid preload.

Adolescent↗
PubMed1996

Why African Americans may not be participating in clinical trials.

African Americans have been underrepresented in clinical trials. This study was designed to determine factors that may help explain the low participation rate of African Americans in clinical trials. A historical review documented past medical experimentation and other practices on blacks that were often brutal and unethical. These experiences may have served to fortify the legacy of African-American mistrust in the medical system and culminated in the infamous Tuskegee Syphilis Study. Four major barriers to participation in clinical trials were identified: lack of awareness about trials, economic factors, communication issues, and mistrust. These barriers, as well as others, can be surmounted with proper pretrial planning, patient education, genuine commitment and concern by study staff, and hard work to overcome deficiencies.

Black or African American↗
PubMed1995

A randomized, prospective study of adjunctive ceftizoxime in preterm labor.

OBJECTIVE: Our purpose was to determine the effect of ceftizoxime in the prolongation of pregnancies receiving tocolysis for preterm labor. STUDY DESIGN: A prospective, randomized, double-blinded, placebo-controlled trial was conducted in patients with preterm labor between 24 and 35 weeks' gestation. A total of 545 patients with intact membranes and without chorioamnionitis who were receiving magnesium sulfate were screened. Exclusions were for advanced cervical dilatation, penicillin allergy, current antibiotic therapy, and failure to give informed consent. Of these, 117 consecutive, eligible, consenting patients were randomized to receive either 2 gm of ceftizoxime or a placebo every 8 hours. The primary end point was prolongation of gestation. Statistical comparisons were performed by use of unpaired two-tailed t tests and chi 2 analysis. RESULTS: Of the 58 ceftizoxime and 59 placebo patients, there was no difference in the interval to delivery (34.5 +/- 21.1 days vs 34.6 +/- 24.5 days, p = 0.99) and no difference in the rate of delivery before 37 weeks' gestation (60% in the ceftizoxime group vs 58% in the placebo group, p = 0.91). Subanalyses of 61 subjects who received nine or more doses and who were group B streptococci negative, 69 patients at < or = 32 weeks on presentation, and 22 sets of twins all showed no differences in delivery interval or rate of delivery at < 37 weeks. The sample size of this study was sufficient to detect a 9-day difference in prolongation of pregnancy (alpha = 0.05, beta = 0.2). CONCLUSIONS: Ceftizoxime had no effect on interval to delivery or duration of pregnancy in women treated for preterm labor.

Adolescent↗
PubMed1995

Cervical competence as a continuum: a study of ultrasonographic cervical length and obstetric performance.

OBJECTIVE: Our purpose was to investigate the hypothesis that cervical competence is a continuum that is related to cervical length and is reflected by pregnancy history. STUDY DESIGN: A cross-sectional study was performed of cervical length measured by transvaginal ultrasonography in women with prior preterm delivery at < or = 26 weeks, 27 to 32 weeks, and 33 to 35 weeks compared with women with cervical incompetence and normal controls delivered at term. RESULTS: Transvaginal cervical length was measured during pregnancy in 32 subjects with cervical incompetence, 98 with previous preterm birth < or = 26 weeks, 98 with previous preterm birth at 27 to 32 weeks, 127 with previous preterm birth at 33 to 35 weeks, and 106 normal controls. The relationship between obstetric history and cervical length was evaluated by analysis of variance. The gestational age at the first preterm delivery was significantly correlated with cervical length in the current pregnancy at each gestational interval between 20 and 30 weeks in a continuous manner. CONCLUSION: Cervical competence is a continuous rather than categoric variable and is indicated indirectly by measurement of the length of the cervix.

Adult↗
PubMed1995

Indomethacin.

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Anti-Inflammatory Agents, Non-Steroidal↗