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Biomedical subjects

M A Morgan

Publications and source records attributed to M A Morgan.

At least 73 records · Page 4Linked to original sources
PubMed1996

Prevention of Rh isoimmunization after spontaneous, massive fetomaternal hemorrhage.

Massive fetomaternal hemorrhage has been associated with numerous risk factors and can occur spontaneously. The risk is probably greater when a woman who is Rh negative has an ABO-compatible fetus. We report the case of a gravid, A-negative unsensitized patient who came to the hospital at term complaining of decreased fetal movement over the previous 24 hours. During evaluation, the fetal heart rate was found to have decreased beat-to-beat variability and repetitive late decelerations, and the mother was delivered of a 3,005 gA-positive neonate (by cesarean section) with a hemoglobin level of 2.9 g/dL. An acid elution test showed 400 mL of fetal blood in the maternal circulation, and the patient received 23 ampules (6,900 micrograms) of Rh immune globulin postpartum. The patient's condition was observed for 156 days after delivery; she did not become sensitized to the Rh factor. A massive fetomaternal hemorrhage can occur without any antecedent risk factors, with a risk of subsequent morbidity to the neonate. Sensitization can be prevented by prompt administration of adequate amounts of Rh immune globulin.

ABO Blood-Group System↗
PubMed1995

Postprandial versus preprandial blood glucose monitoring in women with gestational diabetes mellitus requiring insulin therapy.

BACKGROUND: The fetuses of women with gestational diabetes mellitus are at risk for macrosomia and its attendant complications. The best method of achieving euglycemia in these women and reducing morbidity in their infants is not known. We compared the efficacy of postprandial and preprandial monitoring in achieving glycemic control in women with gestational diabetes. METHODS: We studied 66 women with gestational diabetes mellitus who required insulin therapy at 30 weeks of gestation or earlier. The women were randomly assigned to have their diabetes managed according to the results of preprandial monitoring or postprandial monitoring (one hour after meals) of blood glucose concentrations. Both groups were also monitored with fasting blood glucose measurements. The goal of insulin therapy was a preprandial value of 60 to 105 mg per deciliter (3.3 to 5.9 mmol per liter) or a postprandial value of less than 140 mg per deciliter (7.8 mmol per liter). Obstetrical data and information on neonatal outcomes were collected. RESULTS: The prepregnancy weight, weight gain during pregnancy, gestational age at the diagnosis of diabetes and at delivery, degree of compliance with therapy, and degree of achievement of target blood glucose concentrations were similar in the two groups. The mean (+/- SD) change in the glycosylated hemoglobin value was greater in the group in which postprandial measurements were used (-3.0 +/- 2.2 percent vs. 0.6 +/- 1.6 percent, P < 0.001) and the infants' birth weight was lower (3469 +/- 668 vs. 3848 +/- 434 g, P = 0.01). Similarly, the infants born to the women in the postprandial-monitoring group had a lower rate of neonatal hypoglycemia (3 percent vs. 21 percent, P = 0.05), were less often large for gestational age (12 percent vs. 42 percent, P = 0.01) and were less often delivered by cesarean section because of cephalopelvic disproportion (12 percent vs. 36 percent, P = 0.04) than those in the preprandial-monitoring group. CONCLUSIONS: Adjustment of insulin therapy in women with gestational diabetes according to the results of postprandial, rather than preprandial, blood glucose values improves glycemic control and decreases the risk of neonatal hypoglycemia, macrosomia, and cesarean delivery.

Adult↗
PubMed1995

Phosphoryl migration during the chemical synthesis of RNA.

By the use of high sensitivity assay systems, we have measured the occurrence of strand scission and phosphoryl migration that accompany the deblocking of chemically synthesized oligoribonucleotides. Substantial phosphoryl migration was observed for both enzymatically derived poly(uridylic acid) and synthetic uridine oligoribonucleotides 2'-O-protected with the 1-(2-fluorophenyl)-4-methoxypiperidin-4-yl (Fpmp) group, when these species were subjected to the acidic conditions suggested for Fpmp deprotection. Strand scission occurred in parallel and could be demonstrated readily by 5'-32P end labeling, but not by 3'-32P end labeling, of the acid-treated oligoribonucleotides. Increasing the pH of the deprotection solution and decreasing the temperature at which the deprotection was accomplished diminished both phosphoryl migration and strand scission. A mechanism that can rationalize these results is discussed.

Base Sequence↗
PubMed1995

The impact of amniotic fluid volume assessed intrapartum on perinatal outcome.

OBJECTIVE: Our purpose was to determine the value of routine intrapartum amniotic fluid volume assessment on perinatal outcome. STUDY DESIGN: Patients admitted for labor and delivery who were ultimately delivered between January 1988 and June 1989 with a gestational age > or = 26 weeks and who had an intrapartum amniotic fluid index composed the study group. The amniotic fluid index was determined by the four-quadrant technique on admission to labor and delivery. Oligohydramnios was defined as an amniotic fluid index < or = 5 cm (n = 170), borderline oligohydramnios as an amniotic fluid index 5.1 to 8.0 cm (n = 261), and normal amniotic fluid volume as an amniotic fluid index 8.1 to 20 cm (n = 336). Nine patients with an amniotic fluid index > 20 cm were excluded from data analysis. The oligohydramnios and borderline oligohydramnios groups were compared with the normal group with regard to antenatal, intrapartum, and postpartum variables. RESULTS: The groups had similar maternal age, parity, gestational age at delivery, and antenatal complications. Meconium-stained amniotic fluid occurred significantly less often in the oligohydramnios group compared with the normal group (relative risk 0.67, 95% confidence interval 0.49 to 0.92). However, variable decelerations occurred significantly more often in the oligohydramnios group compared with the normal group (relative risk 1.44, 95% confidence interval 1.12 to 1.87), and cesarean delivery for fetal distress also occurred significantly more often (relative risk 6.83, 95% confidence interval 1.55 to 30.4). There was no difference in Apgar scores or neonatal complications between groups. The efficacy of intrapartum-determined oligohydramnios predicting cesarean delivery for fetal distress gave a sensitivity of 78%, a specificity of 74%, a positive predictive value of 33%, and a negative predictive value of 95%. CONCLUSION: The amniotic fluid index for detecting intrapartum oligohydramnios is a valuable screening test for subsequent fetal distress requiring cesarean delivery.

Amniotic Fluid↗
PubMed1995

Naturally occurring insulin autoantibodies in neonates of normal pregnancies and their relationship to insulinemia and birth weight.

OBJECTIVE: The objectives of this study were to determine whether insulin autoantibodies are present in umbilical cord blood from normal pregnancies, determine whether cord blood insulin autoantibody levels correlate with respective maternal levels at delivery, determine whether cord blood insulin autoantibody levels are related to cord blood or maternal insulin levels, and to determine what relationship neonatal birth weight has with either cord blood insulin autoantibody and insulin levels or maternal insulin autoantibody and insulin levels. STUDY DESIGN: Paired umbilical cord and maternal serum samples were taken from 70 normal subjects at delivery. Measurements of serum insulin autoantibody (competitive charcoal radiobinding assay) and insulin (radioimmune inhibition assay) levels were performed. Multiple linear regression analysis and paired t tests were used for data analyses. RESULTS: Neonatal insulin autoantibody levels (120 nU/ml) were more than two times higher than maternal levels (49 nU/ml) (p < 0.001). No correlation was observed between neonatal and maternal insulin autoantibody levels (r = 0.14, p = 0.25). A positive correlation of both neonatal and maternal insulin with birth weight was observed (r = 0.28, p < 0.02; and r = 0.36, p < 0.01, respectively). CONCLUSIONS: These results suggest that the insulin autoantibody levels in fetal cord blood are not related to maternal levels in normal uncomplicated pregnancies. In addition, insulin levels in both maternal and neonatal circulations were positively correlated with increased birth weight in the normal pregnancies studied.

Adult↗
PubMed1995

Antepartum surveillance for a history of stillbirth: when to begin?

OBJECTIVE: A history of stillbirth is universally accepted as an indication for antepartum fetal heart rate testing. Our goal was to examine when fetal testing should begin in an otherwise healthy patient with a history of stillbirth. STUDY DESIGN: This is a nonconcurrent cohort study of patients who were seen for antepartum surveillance from January 1979 to December 1991 with a history of stillbirth as the only indication for testing. Subsequent pregnancies were evaluated for adverse outcomes and abnormal antepartum test results. RESULTS: There was one case of recurrent stillbirth among the 300 study patients. Nineteen patients (6.4%) had one or more positive antepartum surveillance tests (positive contraction stress test or biophysical profile < or = 4). Three patients (1%) had positive tests before 32 weeks, all of whom were subsequently delivered without incident at term. Three patients were delivered for positive tests at < 36 weeks, one by cesarean section for fetal distress. We could not detect a relationship between the gestational age of the previous stillborn and the incidence of abnormal tests or fetal distress in subsequent pregnancies. CONCLUSION: Antepartum surveillance should begin at > or = 32 weeks in the healthy pregnant woman with a history of stillbirth.

Algorithms↗
PubMed1995

Preterm premature rupture of membranes and abruptio placentae: is there an association between these pregnancy complications?

OBJECTIVE: Our purpose was to determine whether the incidence of abruptio placentae is increased in pregnancies with preterm premature rupture of membranes and to assess whether certain clinical risk factors in this group predispose them to have abruptio placentae. STUDY DESIGN: A retrospective cohort study over a 2.5-year period was performed. The study group consisted of 756 singleton pregnancies between 20 and 36 weeks' gestation complicated by preterm premature rupture of membranes and managed expectantly. The control group consisted of 11,240 pregnancies not complicated by preterm premature rupture of membranes and delivered during the same time period. The incidence of abruptio placentae was compared between the two groups. The study group of patients with preterm premature rupture of membranes was further subdivided into cases with (n = 38) and without abruptio placentae (n = 718) and compared. Clinical factors such as admission amniotic fluid index, history of bleeding before or after rupture of membranes, incidence of intrapartum fetal distress, and low 5-minute Apgar scores (< 6), latency-to-delivery interval, gestational age and weight at delivery, and incidence of amnionitis and endometritis were compared. RESULTS: The incidence of abruptio placentae in the study group (38/756, 5%) was significantly higher than that in the control group (97/11, 240, 0.9%) (p < 0.001, odds ratio = confidence interval). Comparison of cases with preterm premature rupture of membranes with and without abruptio placentae demonstrated both groups to have a similar gestational age at delivery, birth weight, latency-to-delivery interval, amniotic fluid index, and infectious morbidity. The group with abruptio placentae had a significantly higher incidence of bleeding before rupture of membranes (six of 38, 15% vs eight of 718, 1%; p < 0.005) and of intrapartum fetal distress (18/38, 46% vs 49/718, 7%; p < 0.0009). CONCLUSIONS: Pregnancies complicated by preterm premature rupture of membranes that are managed expectantly are at significant risk for abruptio placentae. Preterm premature rupture of membranes in such cases is more often preceded by bleeding. These abruptions may predispose the patient to intrapartum fetal distress.

Abruptio Placentae↗
PubMed1995

The "dangerous multipara": fact or fiction?

OBJECTIVE: Our purpose was to compare the intrapartum complication incidence among grand multiparous women with that of age-matched control multiparous women. STUDY DESIGN: A total of 382 grand multiparous women (para > or = 5) were compared with 382 age-matched control subjects (para 2 to 4), all delivering between July 1989 and September 1991. Intrapartum complications classically associated with grand multiparity (abruptio placentae, dysfunctional labor, fetal malpresentation, postpartum hemorrhage, and shoulder dystocia) were compared. RESULT: Both groups had comparable antepartum complications and gestational ages at delivery. The overall intrapartum complication incidence for grand multiparous women was 33% (127/382 patients), not significantly different from that of the control multiparous women, 27% (103/382). Grand multiparity was associated with an increased incidence of macrosomia (16% vs 11%) and a decreased incidence of operative delivery (14% vs 21%). Macrosomia increased the incidence of intrapartum complications from 31% to 46% (p < 0.03) in the grand multiparous patients, and a trend was observed in the multiparous patients, from 26% to 37%. However, when properly controlled, this was noted to be a confounding variable and was not related to parity. CONCLUSIONS: In a largely Hispanic population grand multiparous patients do not have an increased incidence of intrapartum complications.

Adult↗
PubMed1995

Recurrent squamous cell carcinoma of the cervix with pulmonary lymphangitic metastasis.

A case report and review of the world literature are presented to examine all the reported cases of cervical carcinoma manifesting as pulmonary lymphangitic carcinomatosis in order to better understand this rare condition. The clinical and pathologic features of this disease process are reviewed, as are potential treatment options. We present the first reported case of an immunocompromised patient with cervical carcinoma and pulmonary lymphangitic metastasis with a prospective diagnosis made by transbronchial biopsy. Given that this condition carries a uniformly fatal prognosis, unwanted therapy may result from a missed diagnosis. A prospective pathologic diagnosis by transbronchial biopsy may guide appropriate therapy in these patients.

Carcinoma, Squamous Cell↗
PubMed1995

Term early-onset neonatal seizures: obstetric characteristics, etiologic classifications, and perinatal care.

OBJECTIVE: To describe obstetric characteristics and etiologic classifications and assess perinatal care in term neonates with early-onset seizures. METHODS: We performed a retrospective review of neonatal and obstetric records of neonates delivered at term with a diagnosis of early-onset seizures between January 1981 and December 1992 at Long Beach Memorial Medical Center. Data regarding obstetric characteristics and etiologic classifications of the seizures were abstracted from the medical records. Lack of antepartum testing in high-risk patients, delayed intervention with nonreassuring antepartum or intrapartum fetal heart rate patterns, birth trauma, and failure to use prophylactic antibiotics or treat infection were the criteria used for identifying seizures that were potentially preventable. RESULTS: Forty term neonates had early-onset seizures out of 60,712 live births (0.07%). These seizures were attributed to hypoxic events in 15 neonates (37.5%), cerebral malformations in seven (17.5%), cerebral infarcts in seven (17.5%), intracranial hemorrhage in five (12.5%), infection in three, and an unknown etiology in three. Twenty-three neonates had 5-minute Apgar scores of 7 or greater (cerebral malformations excluded). Seven of these neonates (30%) had cerebral infarcts. A review of all records identified nine cases (22.5%) of the early-onset seizures as potentially preventable. CONCLUSION: The majority of the term early-onset neonatal seizures identified did not appear to be preventable. Many of the neonates with 5-minute Apgar scores of 7 or greater had cerebral infarcts.

Adult↗
PubMed1995

Differential contribution of dorsal and ventral medial prefrontal cortex to the acquisition and extinction of conditioned fear in rats.

The emotional reactivity of rats with lesions of the dorsal portion of medial prefrontal cortex (mPFC) was examined using a classical fear conditioning paradigm. Conditioned fear behavior (freezing responses) was measured during both the acquisition and extinction phases of the task. Lesions enhanced fear reactivity to both the conditioned stimulus (CS) and contextual stimuli during both phases, suggesting that dorsal mPFC lesions produce a general increase in fear reactivity in response to fear conditioning. M. A. Morgan, L. M. Romanski, and J. E. LeDoux (1993) found that lesions just ventral to the present lesions had no effect during acquisition of the same task and prolonged the fear response to the CS (but not the context) during extinction. Thus, both dorsal and ventral regions of mPFC are involved in the fear system, but each modulates different aspects of fear responsivity.

Animals↗
PubMed1995

Labor and delivery management of the multiple gestation.

Labor and delivery management of multiple gestations remains controversial. The authors review issues relating to the management of labor and the administration of anesthesia in twin gestations. A comprehensive review of published data pertaining to delivery route planning for twins using fetal presentation, gestational age, and estimated fetal weight is presented. Individualization of intrapartum care in twin gestations is imperative.

Analgesia, Obstetrical↗
PubMed1994

Iron(II) bleomycin-mediated degradation of a DNA-RNA heteroduplex.

The effect of iron(II) bleomycin on a DNA-RNA heteroduplex was investigated using a substrate formed by reverse transcription of Escherichia coli 5S ribosomal RNA. Both strands of the heteroduplex were cleaved by FeII.BLM A2 at comparable concentrations; complete digestion of both strands was observed using 5 microM FeII.BLM A2. The DNA strand of the heteroduplex was cleaved predominantly at 5'-G-pyr-3' sites; the sites of cleavage of the DNA strand were a subset of those observed for the corresponding DNA strand of a DNA duplex of identical sequence. The sites of cleavage of the RNA strand of the heteroduplex involved both purines and pyrimidines and were found to be different than the sites of cleavage of the 5S rRNA alone, demonstrating that cleavage of the former must actually have involved heteroduplex recognition by FeII.BLM A2. Both the DNA and RNA strands of the heteroduplex were cleaved by FeII.BLM A2 in the presence of physiological concentrations of Mg2+, consistent with the possibility that DNA-RNA heteroduplexes may be therapeutically relevant targets for bleomycin.

Base Sequence↗
PubMed1994

Application of backpropagation neural networks to diagnosis of breast and ovarian cancer.

Neural network programs have been developed in an attempt to improve the diagnosis of breast and ovarian cancer using a group of laboratory tests and the age of the patient. The laboratory tests employed in this study include albumin, cholesterol, HDL-cholesterol, triglyceride, apolipoproteins A1 and B, NMR linewidth (the Fossel Index) and a tumor marker (i.e., CA 15-3 or CA 125). The breast cancer study involved 104 patients (45 malignant and 59 benign subjects). The ovarian cancer study involved 98 individuals (35 malignant, 36 benign and 27 control subjects). Methods are outlined for identification of the most influential input parameters and optimization of network structure and training. Network characteristics were contrasted with the test results of the appropriate serum tumor marker assay. For the breast cancer study, the best neural network program, using six input parameters, had a sensitivity of only 55.6% and a specificity of 72.9%. The tumor marker CA 15-3 alone gave results of 61.3% and 64.4%, respectively. For the ovarian cancer study, the best neural network program, using six input parameters, had a sensitivity of 80.6% and a specificity of 85.5%. The tumor marker CA 125 alone gave results of 77.8% and 82.3%, respectively. These methods provide an objective approach to neural network optimization and parameter selection applicable to other data bases of clinical and laboratory data.

Biomarkers, Tumor↗
PubMed1994

Gestational diabetes: does the presence of risk factors influence perinatal outcome?

OBJECTIVE: Our purpose was to determine whether gestational diabetics with risk factors for gestational diabetes have worse glucose tolerance and poorer birth outcomes than those without risk factors. STUDY DESIGN: We conducted a nonconcurrent cohort study of gestational diabetics identified by universal screening and delivered from Jan. 1, 1990, to Dec. 31, 1992. Multiple gestations and patients with chronic medical conditions were excluded. The following risk factors for gestational diabetes mellitus were abstracted: obesity (> 80 kg), family history of diabetes, previous gestational diabetes mellitus, and previous macrosomic, stillborn, or anomalous fetus. Patients with one or more risk factors were compared with those without risk factors. A group of low-risk nondiabetic patients served as controls. The incidences of A2 diabetes mellitus, cesarean section, neonatal macrosomia, and shoulder dystocia were the outcome variables of interest. RESULTS: Selective screening would have failed to detect 43% of gestational diabetics. Twenty-eight percent of the missed gestational diabetics would have required insulin (class A2). When compared with controls, patients with gestational diabetes mellitus were at increased risk for macrosomia (26% vs 11%, p < 0.01), cesarean section (37% vs 15%, p < 0.01), and shoulder dystocia (9% vs 2%, p < 0.05). Patients with and without risk factors did not differ in mean maternal age, gestational age at delivery, birth weight, incidence of requiring insulin, macrosomia, or cesarean delivery. The similarities between those with and without risk factors remained after stratification by maternal age (> or = 30 years). CONCLUSION: Gestational diabetics are at increased risk for adverse birth outcomes compared with low-risk controls. Class A2 diabetes mellitus and fetal macrosomia with its attendant risks are equally prevalent among patients with and without risk factors for gestational diabetes mellitus. Because > 40% of cases will be missed with selective screening, universal screening should be favored for detection of gestational diabetes mellitus.

Adult↗
PubMed1994

Endometriosis and tamoxifen therapy.

Tamoxifen is an estrogen antagonist/agonist often associated with antiestrogenic effects such as hot flushes and vaginal dryness in premenopausal women. Estrogenic side-effects, such as thromboembolic phenomena and endometrial proliferation has been reported in postmenopausal women. Paradoxically, tamoxifen has also been shown to be capable of increasing estrogen levels in premenopausal women. Since tamoxifen is being used more frequently in this group of women, potential adverse effects are only now being recognized. Two cases of premenopausal women who developed symptomatic endometriomas while on tamoxifen for breast cancer, are reported. Stimulation of endometriosis should be considered when pain and an ovarian mass develops in a woman on tamoxifen. The unique effects of tamoxifen in premenopausal women may contribute to this even in the presence of regular ovulation.

Adult↗