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Biomedical subjects

H Schulman

Publications and source records attributed to H Schulman.

At least 181 records · Page 10Linked to original sources
PubMed1985

Meconium aspiration and fetal acidosis.

Meconium in labor is associated with increased perinatal morbidity and mortality. To identify the infants at risk, 53 women with moderate-to-thick meconium were followed in labor after obtaining baseline fetal scalp blood pH levels. Although 28 of the newborns (53%) exhibited an arterial cord pH of less than 7.25 at delivery, there were no significant predictive variables found in the electronic fetal monitoring score, Apgar score, or mode of delivery. Nine of the infants with a pH value of less than 7.25 had meconium below the vocal cords at delivery, but none in the infants with pH levels greater than or equal to 7.25. The P50 value for cumulative acidosis is 55 minutes, indicating a more rapid deterioration than an average-for-gestational-age fetus without meconium. Therefore, the presence of thick meconium implies that fetal stress must be avoided during labor, and early intervention is warranted when there is deviation from normal labor progress or fetal heart rate pattern.

Acidosis↗
PubMed1985

Current dilatation and curettage practice: a need for revision.

A ten-year retrospective review of 1383 diagnostic dilatation and curettages (D&C) was done at a university hospital. It was found that the detection or diagnosis of uterine cancer did not significantly increase until after the age of 50. No significant pathologic findings were detected in 60% or more of the women until the age of 70. Premalignant or other than benign tissue was observed to increase from 4% in the age 29 or less group to a peak of 16% in the age 45 to 49 group. The authors conclude that the current practice of routine D&C for abnormal uterine bleeding provides a low yield of cancer diagnoses, and that the indications for this procedure should be sharply reduced or replaced by simpler methods.

Adult↗
PubMed1985

Antepartum nonstress test and the postmature pregnancy.

A review of 4320 consecutive term deliveries identified 258 women (6%) delivered at a gestational age of 42 weeks or longer. The group accounted for 30% of all cesarean sections for fetal distress, 30% of all infants with a low five-minute Apgar score, 40% of neonatal intensive care admissions, 60% of neonatal deaths, and 30% of all stillbirths. Nonstress tests were performed on 228 women with a postmature pregnancy. Results were defined as normal (score 7 to 10) in 83.4%, inconclusive (score 5 to 6) in 12.2%, and abnormal (score 1 to 4) in 4.4% of these cases. Monitored patients did significantly better than patients in the nonmonitored group, and so did those with normal nonstress test scores when compared with the abnormal scores. Whereas perinatal mortality in the monitored group was similar to that in the nonpostmature population, the perinatal morbidity was significantly higher.

Apgar Score↗
PubMed1984

Purification and characterization of a Ca2+/calmodulin-dependent protein kinase from rat brain.

A soluble Ca2+/calmodulin-dependent protein kinase has been purified from rat brain to near homogeneity by using casein as substrate. The enzyme was purified by using hydroxylapatite adsorption chromatography, phosphocellulose ion-exchange chromatography, Sepharose 6B gel filtration, affinity chromatography using calmodulin-Sepharose 4B, and ammonium sulfate precipitation. On sodium dodecyl sulfate (NaDodSO4)-polyacrylamide gels, the purified enzyme consists of three protein bands: a single polypeptide of 51 000 daltons and a doublet of 60 000 daltons. Measurements of the Stokes radius by gel filtration (81.3 +/- 3.7 A) and the sedimentation coefficient by sucrose density sedimentation (13.7 +/- 0.7 S) were used to calculate a native molecular mass of 460 000 +/- 29 000 daltons. The kinase autophosphorylated both the 51 000-dalton polypeptide and the 60 000-dalton doublet, resulting in a decreased mobility in NaDodSO4 gels. Comparison of the phosphopeptides produced by partial proteolysis of autophosphorylated enzyme reveals substantial similarities between subunits. These patterns, however, suggest that the 51 000-dalton subunit is not a proteolytic fragment of the 60 000-dalton doublet. Purified Ca2+/calmodulin-dependent casein kinase activity was dependent upon Ca2+, calmodulin, and ATP X Mg2+ or ATP X Mn2+ when measured under saturating casein concentrations. Co2+, Mn2+, and La3+ could substitute for Ca2+ in the presence of Mg2+ and saturating calmodulin concentrations. In addition to casein, the purified enzyme displayed a broad substrate specificity which suggests that it may be a "general" protein kinase with the potential for mediating numerous processes in brain and possibly other tissues.

Animals↗
PubMed1984

Pharmacological characterization of histamine H2 receptors on clonal cytolytic T lymphocytes. Evidence for histamine-induced desensitization.

Cultured cytolytic T lymphocytes of clonal origin were screened for histamine-stimulated cyclic AMP production. Histamine caused a 2- to 8-fold elevation of cyclic AMP levels in five independent clones. The EC50 for histamine of 1.7 X 10(-5) M and the rank order of potencies of H1 and H2 agonists [impromidine greater than histamine greater than dimaprit greater than 4-methylhistamine greater than 2-methylhistamine greater than 2-(2-aminoethyl)-thiazole] were characteristic of the conventional histamine H2 receptor. H1 and H2 antagonists inhibited histamine-stimulated cyclic AMP elevation with inhibition constants typical for those found on other H2 receptor systems. Prior incubation of cells with histamine resulted in a marked loss in responsiveness to subsequent histamine challenge. We demonstrate that this desensitization is dose and time dependent and results in a change in the efficacy and not the potency of histamine. Although cyclic AMP increases could also be elicited with isoproterenol, prostaglandin E1 or forskolin, desensitization of histamine had no effect on the ability of these agents to stimulate cyclic AMP production. In contrast to the rapid rate of histamine-induced desensitization, recovery of histamine responsiveness could not be detected for several hours.

1-Methyl-3-isobutylxanthine↗
PubMed1984

Umbilical velocity wave ratios in human pregnancy.

Umbilical artery velocity waves were measured in the fetuses from 130 pregnant women. One hundred eighty-five determinations were carried out from the fourteenth to the fortieth weeks of pregnancy. Detection of waveforms was carried out on an Angioscan Doppler spectrum analyzer. The umbilical artery velocity waves can be differentiated from other fetal signals by recognition of the pattern. The systolic peak of the velocity wave was divided by the end-diastolic value, thereby giving an S/D ratio. The use of a ratio overcomes the obstacle of not knowing the angle between the incident beam and the direction of motion. The umbilical velocity wave S/D ratio in normal pregnancies declines from 2.8 to 2.2 from 25 to 41 weeks. In pregnancies which result in a small-for-gestational age (SGA) fetus, the ratio is significantly higher, showing an average level of 3.8 at 29 weeks and declining to 3.0 at 40 weeks. Abnormal umbilical velocity wave values are seen in an SGA fetus, unexplained fetal death, poorly controlled diabetes mellitus, and a twin transfusion syndrome. Application of this technique has the potential of being an important aid in prenatal care.

Female↗
PubMed1984

Phosphorylation of microtubule-associated proteins by a Ca2+/calmodulin-dependent protein kinase.

In an earlier study I demonstrated that rat brain cytosol contains a Ca2+/calmodulin-dependent protein kinase activity that phosphorylates microtubule-associated protein 2 (MAP-2) but not MAP-1. Comparison of sites of phosphate incorporated in MAP-2 catalyzed by the Ca2+/calmodulin-dependent kinase activity and the cyclic AMP-dependent protein kinase activity in cytosolic extracts revealed distinct sites of phosphorylation (Schulman, H., 1984, Mol. Cell. Biol., 4:1175-1178; abstract by me and J.A. Kuret and K.H. Spitzer [1983, Fed. Proc., 42:2250]. I have now used MAP-2 as a substrate to purify the Ca2+/calmodulin-dependent protein kinase responsible for MAP-2 phosphorylation. The brain appears to contain a single predominant Ca2+/calmodulin-dependent protein kinase that phosphorylates MAP-2. The enzyme was purified to apparent homogeneity by column chromatography using DEAE-cellulose, phosphocellulose, hydroxylapatite, Sepharose 6B, and a calmodulin-Sepharose affinity column. The 580,000-dalton holoenzyme consists of 51,000- and 60,000-dalton subunits. The purified enzyme phosphorylates MAP-2 at the same "sites" that are phosphorylated in cytosolic extracts and thus has the same specificity as the activity present in cytosol. Analysis of phosphorylated MAP-2.1 and MAP-2.2, the two components of MAP-2, suggests considerable homology in their phosphorylated domains.

Animals↗
PubMed1984

Differential phosphorylation of MAP-2 stimulated by calcium-calmodulin and cyclic AMP.

Comparison of cyclic AMP- and calcium-dependent phosphorylation in rat brain cytosol reveals MAP-2 to be a common endogenous substrate. Examination of limited protease digestion patterns indicates that the two kinases phosphorylate MAP-2 at distinct sites and suggests that such phosphorylation may have differential effects on MAP-2 function.

Animals↗
PubMed1984

Role of prostaglandin-induced cervical changes in labor induction.

The role of the cervix in labor induction has been studied in a previous report. Cervical preparation by mechanical methods did not alter the course of induced labor. The same hypothesis is further elucidated in the present study using prostaglandin E2 vaginal suppositories for cervical preparation. Forty-seven pregnant women near term with Bishop scores of 4 or less were divided into three study groups: control subjects, oxytocin-treated patients, and prostaglandin group. A 12-hour preparation phase procedure was carried out to produce cervical and/or myometrial changes. All women had continuous measurement of uterine activity by an extraovular catheter. At the end of the preparation phase, the Bishop score was reevaluated, amniotomy carried out in all patients, and oxytocin infusion either started or continued. Although prostaglandin and oxytocin both significantly changed the cervix, oxytocin had the shortest induction-to-delivery interval, though the prostaglandin-treated group required lower concentrations of oxytocin. The authors conclude that with rigid control of Bishop score and timing of amniotomy and oxytocin infusion rates, prostaglandin-induced cervical changes alone did not uniquely benefit labor induction in the doses used, or within the time frame of the study.

Adult↗
PubMed1984

Fetal acidosis and the abnormal fetal heart rate tracing: the term breech fetus.

The intrapartum fetal heart rate tracings of 27 terms fetuses in breech presentation were analyzed to evaluate their immediate neonatal outcome. The tracings were quantitatively evaluated for comparison with Apgar scores and umbilical cord gases at delivery. Of the 27 cases, 12 had monitoring strips that scored 4 or less before birth. The P50 for acidosis at delivery (an umbilical artery pH of 7.25 or less) was 55 minutes for an intrapartum tracing that scored 4 or less. Fetuses with intrapartum tracings scoring 8 or more throughout labor had normal Apgar scores and cord gases. In comparing the present data with those of a previous study of vertex presentations, the authors found that given similar tracings, the breech fetus deteriorates more rapidly than the vertex fetus. Cesarean section is recommended if delivery is not imminent in a laboring breech and the intrapartum tracing deteriorates to score 4 or less.

Acidosis↗
PubMed1984

Maternal plasma and amniotic fluid levels of estradiol, estrone, progesterone, and prolactin in early pregnancy.

During the 16th to 20th weeks of gestation, maternal plasma (mean) level of estradiol is 5.2 ng/mL; estrone, 3.0 ng/mL; estriol, 2.1 ng/mL; progesterone, 4235 ng/dL; and prolactin, 74 ng/mL. Amniotic fluid levels are: estradiol, 446.8 pg/mL; estrone, 234.1 pg/mL; progesterone, 5200 ng/dL; and prolactin, 2633.5 ng/mL. Maternal prolactin concentrations correlate with plasma estradiol. Amniotic fluid prolactin levels correlate significantly with maternal plasma concentrations of estradiol and estrone. The mechanisms for the possible relationship between maternal estradiol and pituitary and decidual tissue production of prolactin are discussed.

Amniotic Fluid↗
PubMed1983

The uterine contractility index: a research and diagnostic tool in dysmenorrhea.

Women who experienced severe primary dysmenorrhea had 90 to 120 minutes of continuous uterine pressure monitoring during their peak period of discomfort. During the initial screening cycle, they were given 40 mg of piroxicam, a nonsteroidal anti-inflammatory drug which inhibits prostaglandin synthesis. The pressure tracings were analyzed by a newly proposed ratio, the contractility index. During the painful period, the contractility index averaged approximately 3. When relief was experienced, the contractility index fell to approximately 1.5. Women who experienced uncertain or slight relief had a contractility index of approximately 2. Relief was experienced by 69% of the women screened. A small double-blind, crossover study was carried out on seven of the women. This revealed different responses to the drug in consecutive cycles and suggests that increased prostaglandins are an expression of an underlying process, not consistent with a primary cause of dysmenorrhea.

Adolescent↗
PubMed1983

Acetylation and calcium-dependent phosphorylation of histone H3 in nuclei from butyrate-treated HeLa cells.

In HeLa nuclei, 1 microM Ca2+ stimulates 3-fold the phosphorylation of histone H3. Prior treatment of cells with Na butyrate increases the degree of H3 phosphorylation and reveals a correlation between the extents of H3 acetylation and phosphorylation. Acetylation of H3 increases its accessibility to the calcium-dependent kinase. Phosphorylation of H3 occurs at a serine residue located in the trypsin-sensitive region of the protein. Brief digestion of nuclei with DNase I preferentially releases the phosphorylated form of H3 from chromatin.

Acetylation↗
PubMed1982

The development of fetal acidosis in the presence of an abnormal fetal heart rate tracing. I. The average for gestational age fetus.

An abnormal fetal heart rate (FHR) tracing is a sensitive indicator of positivity that disease exists, but the intrinsic predictive value of such a tracing is disappointingly low because of the large number of false positive results. Abnormal FHR tracings, defined as those having a persistent quantitative score of 4 or less, were measured against time and outcome. A baseline fetal scalp blood sample was taken. Twenty fetuses were acidotic at the first blood sample. There were 121 study cases, all of which were greater than 37 weeks' gestational age. All fetuses were average for gestational age. Amniotic fluid was clear, internal FHR tracings were initially normal, and the first pH was normal. A relative acidosis-free interval could be demonstrated during the first 90 to 100 minutes. Following this time period rapid cumulative acidosis was seen, which varied according to the FHR pattern observed. The P50 acidosis values for various patterns were late decelerations, 115 minutes; variable decelerations, 145 minutes; and flat line tracings, 185 minutes.

Acidosis↗