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Biomedical subjects

M Tobias

Publications and source records attributed to M Tobias.

53 records · Page 3Linked to original sources
PubMed1981

Effect of aminophylline on the synthesis of dipalmitoyl phosphatidyl choline in fetal rabbit lung.

Aminophylline (A) administration to pregnant rabbits resulted in accelerated formation of phospholipids, the known important components of pulmonary surfactant [1]. The present study was undertaken to determine the effect of A on one of the pathways involved in the incorporation of palmitic acid into phosphatidyl choline (PC)--the "deacylation-reacylation pathway." A was injected intraperitoneally into rabbit fetuses at 27 days of gestation and its effect on palmitoyl CoA synthetase (PCS) and lysopalmitoyl choline acyl transferase (LPC-AT) were studied. Only LPC-AT was enhanced significantly (P less than 0.05) as a result of direct administration of A. This study supports the suggestions by previous investigators that antenatal administration of aminophylline may prove to be an effective means of enhancing lung maturation by stimulating the formation of pulmonary surfactant production before premature delivery. However, the dose that was used in this experimental study was far more than the usual clinical dose that had been suggested previously.

1-Acylglycerophosphocholine O-Acyltransferase↗
PubMed1981

Terbutaline-induced changes in ovine, fetal and maternal hemodynamics, and fetal electroencephalogram.

Terbutaline has been used in obstetrics to treat premature labor. Its effect was studied in six ewes and their fetuses at gestational ages of 140 +/- 0.5 days (term approximately 147 days). Terbutaline (1,500 microgram) was infused over 34.5 minutes to the six anesthetized ewes. Post-baseline changes of maternal and fetal blood pressure (MBP, FBP), heart rate (MHR, FHR) and acid-base values, uterine blood flow (QUA), fetal cerebral blood flow (QFC), and fetal cerebral function (EEG) and metabolism were studied at 10, 20, 30 and 60 minutes. Terbutaline caused maternal tachycardia, hypotension, metabolic acidosis, hyperglycemia, and mild lactic acidemia without affecting PO2, O2 saturation (O2%), O2 content, or uterine blood flow. In the fetus, metabolic acidosis, lactic acidemia, hyperglycemia, and increased glucose consumption resulted, whereas PO2, PCO2, O2 consumption, fetal cerebral blood flow, heart rate, blood pressure, and EEG remained unchanged. It is suggested that terbutaline, although causing transient maternal tachycardia and hypotension, does not decrease uterine blood flow or alter fetal PO2 or EEG. It is further suggested that it reduces maternal and fetal pH due to lactic acidemia.

Animals↗
PubMed1981

Cardiovascular and hematologic effects of diphenylhydantoin in maternal and fetal sheep.

Anticonvulsant therapy often includes diphenylhydantoin (Dilantin) and is usually advocated during the pregnancy of an epileptic woman. The cardiovascular and hematologic effects of diphenylhydantoin (5 mg/kg body weight/5 min) were studied in 12 experiments on 5 ewes and their fetuses in which catheters were chronically implanted and an electromagnetic flow probe was continually around the uterine artery. Slight but significant transient decreases in fetal blood pressure (P less than .001), oxygen percent saturation (O2%, P less than .02) and O2 content (P less than .01) were observed. These parameters recovered to baseline values within 75 minutes after infusion was begun, and no other fetal changes were noted. Maternal metabolic alkalosis was evidenced by significant increases in pH (P less than .001) bicarbonate (P less than .05), and base excess (P less than .02). A slight decrease in the percent hemoglobin was observed at 15, 60, and 90 minutes (P less than .02, P less than .05, and P less than .01, respectively). No changes were observed in maternal heart rate or uterine blood flow, though an increase in blood pressure was observed at 30 minutes (P less than .05). From these observations, it is concluded that the administration of diphenylhydantoin intravenously causes transient fetal hypotension, reduction of O2%, maternal metabolic alkalosis, and transient hypertension without any changes in fetal pH, PCO2, or uterine blood flow. Therefore, it can be considered a relatively safe drug to be used during pregnancy.

Acid-Base Equilibrium↗
PubMed1981

Effects of isoxsuprine on maternal and fetal acid-base balance and circulation.

Prematurity is a large contributing factor to neonatal morbidity. An obstetric alternative to premature labor is administration of isoxsuprine, an effective inhibitor of uterine contractions. Six crossbred unanesthetized pregnant ewes were used to determine the effects on fetal and maternal cardiovascular and acid-base status of 10 maternal intravenous infusions of 30 mg isoxsuprine over 30 minutes (1 mg/min). Isoxsuprine caused slight maternal hypotension and a transient acidosis, both of which returned to baseline values within 60 minutes. Maternal tachycardia persisted throughout the experiment. A slight decrease in the oxygen percent saturation of the hemoglobin and the calculated O2 content was observed after the infusion. There was no significant change in uterine blood flow. Maternal lactate concentration transiently increased at 60 minutes only. In the fetus, isoxsuprine caused transient hypotension and tachycardia. Fetal arterial PCO2, calculated bicarbonate concentration, and O2 content all decreased slightly at 45 minutes only. Fetal hyperglycemia was observed after the infusion throughout the experiment. All other fetal values returned to baseline levels within 60 minutes. It is suggested that 30 mg isoxsuprine can cause tolerable maternal and fetal metabolic and physiologic effects when administered intravenously to the unanesthetized pregnant ewe.

Acid-Base Equilibrium↗
PubMed1980

Studies of circulation and acid-base balance in pregnant sheep: I. The effect of aminophylline infusion.

The maternal and fetal effects of aminophylline on hemodynamics and acid-base and blood gas balances were evaluated by 11 infusions to four chronically catheterized sheep at 114-142 days' gestation. Maternal and fetal arterial blood samples were drawn for baseline determination at 15-minute intervals. Mean maternal and fetal pH levels and heart rates increased significantly. Respiratory alkalosis was indicated by a concomitant fall in mean maternal carbon dioxide pressure. We conclude that aminophylline infusion (5.6 mg/kg of body weight/15 min) to pregnant sheep may cause maternal and fetal tachycardia and alkalosis, with a possible increase in uterine blood flow, but no changes in fetal blood gas status or blood pressure.

Acid-Base Equilibrium↗
PubMed1980

Studies of circulation and acid-base balance in pregnant sheep: II. The effect of magnesium sulfate infusion.

Ten infusions of magnesium sulfate, in clinical doses for toxemia therapy, were administered to seven chronically catheterized ewes at 109-126 days' gestation. Maternal and fetal Mg++ concentrations in arterial serum indicated hindered placental passage. A significant decrease in maternal arterial oxygen pressure and hemoglobin was seen at 15 minutes. A significant increase in maternal arterial carbon dioxide pressure and transient maternal hypotension and tachycardia were seen at five minutes. Fetal effects of maternal infusion were minimal and transient. All maternal and fetal parameters returned to control levels by 90 minutes.

Acid-Base Equilibrium↗
PubMed1980

The effects of scopolamine and ancillary analgesics upon the fetal heart rate recording.

Sixty-two fetal heart rate/uterine contraction recordings were examined prior to and following the administration of analgesia. Two groups, identified according to the receipt or absence of scopolamine, were evaluated concerning modification of baseline variability, beat-to-beat variability and fetal heart rate deceleration patterns. Scopolamine was found to be capable of eliciting fetal tachycardia, decreased beat-to-beat and baseline variability and decreased fetal heart rate decelerations. The mean one-minute Apgar scores for the two groups did not differ from each other nor from that of a control group that had not received any analgesia during labor.

Female↗
PubMed1979

Effects of ethanol on the circulation and acid-base balance of pregnant sheep.

Nine infusions of 15 cc/kg/120 min of 9.5% ethanol were administered to 4 chronically catheterized ewes, at 109-135 days' gestation. Stabilization periods ranged from 6 to 28 days postoperatively. Maternal and fetal concentrations of ethanol were almost identical (r = 0.9925), with peak levels of 122 +/- 20 mg/100 ml (mean +/- 1 SE) and 121 +/- 19 mg/100 ml, respectively, at the end of infusion. Maternal pH decreased from 7.50 +/- 0.02 to 7.44 +/- 0.02 (P less than 0.005) at 120 minutes. Maternal glycemia increased from 76 +/- 14 mg/100 ml to 162 +/- 23 mg/100 ml (P less than 0.005) at 120 minutes. Maternal heart rate, blood pressure, PO2, O2 content, PCO2, and bicarbonate remained unchanged. Fetal PO2 increased during and following infusion from 18.9 +/- 0.9 mmHg to 22.0 +/- 1.0 mmHg (P less than 0.005) at 180 minutes. Fetal blood pressure increased from 51.3 +/- 3.1 mmHg to 53.7 +/- 3.3 mmHg (P less than 0.01) at 30 minutes. Fetal pH, PCO2, glucose, and lactate levels remained unchanged. The authors conclude that ethanol crosses the sheep placenta readily, causes maternal acidosis and hyperglycemia, and increases fetal PO2, blood pressure, and heart rate without any effects on fetal acid-base status.

Acid-Base Equilibrium↗
PubMedDate not supplied

Correlation of ominous fetal heart rate pattern and scalp blood pH with one-minute Apgar score.

Fetal minitoring data were analyzed in 176 labors that developed ominous fetal heart rate deceleration patterns (FHRDP) during the two hours prior to delivery in an effort to identify how neonatal condition could be most accurately predicted. It was found that ominous FHRDP corresponded to a one-minute Apgar score of 6 or less in only 15.3% of cases. When patterns with fetal scalp blood pHs (FSBpH) of less than or equal to 7.20 (n = 18) were considered, 44.4% had an Apgar score of 6 or less. Mean Apgar scores for those neonates who had a pH of less than or equal to 7.20 were significantly less than the mean Apgar score of the control group (p less than 0.001 for all deceleration types). The result reveals that FSBpH has a better predictive value than FHRDP alone for neonatal depression. It is suggested that, as soon as ominous FHRDP occurs during labor, FSBpH be performed to assess not only fetal status but also to predict neonatal outcome.

Apgar Score↗
PubMedDate not supplied

The significance of sinusoidal fetal heart rate pattern during labor and its relation to fetal status and neonatal outcome.

Twenty-seven cases of sinusoidal fetal heart rate were studied. This group had a mean scalp pH of 7.288, significantly lower (p less than 0.005) than that of the control group. The mean one-minute Apgar score was 7.148, significantly lower (p less than 0.001) than the control group's mean score. Almost half (48,15%) of the fetuses had a one-minute Apgar score of 7 or less. Every fetus was viable. Amplitude of the pattern was found to correlate with neonatal depression, the larger the amplitude, the more profound the depression. Over 96% of the fetuses had cord-related deceleration patterns, and nearly 63% had obvious cord complications. It is postulated that sinusoidal patterns are an umbilical cord-related phenomenon, resulting from an alternating hypovolemia and hypervolemia. Clinicians are urged to scrutinize carefully any cases of this pattern, and perform an immediate fetal scalp blood pH determination. If the pH determination obtained is less than 7.25, the authors suggest intervention and operative delivery.

Apgar Score↗
PubMedDate not supplied

A study of three preoperative sedative combinations.

The use of drugs as premedication for child patients to be treated in the office may provide the dentist with an adequate means of controlling the patient otherwise incapable of cooperation. Drug dosages for children cannot be determined alone on the basis of weight and age, especially when dental treatment is to be provided. Alphaprodine and promethazine; chloral hydrate and hydroxyzine pamoate; pentobarbital, meperidine, and scopolamine are three groups of balanced medication that fulfill the needs in pedodontic office procedures. The Pedi-Wrap is an important factor in treatment and control of movements unknowingly exhibited by the patient from one to six years of age. Its use should be required for the very young child patient, to prevent falls and bodily injury and to allow the doctor to execute his treatment effectively.

Adolescent↗