Biomedical subjects
Publications and source records attributed to E C Davidson.
Preliminary experience with fetoscopy and fetoplacental blood sampling in 23 midtrimester pregnant baboons demonstrated the procedure to be successful in 19 cases (83%); seven serious complications (30%) developed, most of which might well have been avoided with operative experience and other complimentary procedures.
To demonstrate increased technical experience with fetoscopy and fetal blood sampling, two groups of macaques were compared to control animals. Group 2 had a perinatal mortality rate that was not significantly different from that of the control group. A 2.7 mm. Hopkins rod lens endoscope encased in an eccentric cannula, 3.8 mm. outside diameter, was used. When compared to the earlier test group (Group 1), the later test group (Group 2) showed greater adequacy of the fetal blood sample for laboratory analysis (P less than 0.01). Anthropometric and hematologic data collected at term births compared favorably in test and control groups, with the exception of the white blood cell count, which was significantly lower with fetoscopy (P less than 0.01). This is the first report of experimental fetoscopy with the use of a control group to provide precise data to aid in clarification of the ethical issues yet unresolved in this technology.
A mature lowland gorilla (Gorilla gorilla) in the Los Angeles Zoo had destroyed 3 successive infants. To avoid a recurrence, active intervention was instituted during its 4th pregnancy. The period of gestation was estimated by physical examination, radiography, and amniocentesis. Intrauterine growth was followed by serial ultrasonographic cephalometry. When fetal maturity was achieved, as determined by amniotic fluid phospholipid profile, the fetus was delivered by cesarean section.
We serially tested 26 healthy, young, nulliparous patients, while they were maintained in the left lateral recumbent position, during a four-week interval (29 to 32 weeks), with progressive increments of angiotensin-II (A-II) 2.0 to 15.0 ng. per kilogram per minute). Blood pressure was recorded with an ultrasound device. All patients were followed through delivery. Three patients (12 per cent) developed pregnancy-induced hypertension (PIH); only one of these demonstrated enhanced vasoreactivity prior to PIH. Conversely, 13 patients who did not develop PIH demonstrated enhanced vasoreactivity at least once during the testing interval. Comparison of results obtained from one week to the next was evaluated in 57 test pairs; discordant data, i.e. reaction to less than 8 ng. per kilogram per minute one week and nonreaction the next, was observed in 17 pairs (30 per cent). We conclude that assessment of the risk of PIH, with the use of the diastolic pressor response to infused A-II, is unreliable.
The normal flora of the cervix was studied in 50 healthy women in labor and on the third day postpartum. Aerobic bacteria were the exclusvie isolates in 25% of these women, and 75% had anaerobic bacteria in addition to aerobes. Anaerobes were always found in association with aerobes. The most frequent isolate of Bacteroides was Bacteroides melaninogenicus, found in 20% of the women during labor and 14% during the puerperium. Bacteroides fragilis was distinctly absent during labor but was found in 6.8% of the women during the puerperium. Clostridia were found in 1% but histotoxic clostridia were not found. None had gram-negative diplococci (Neisseria or Veillonella). Gram-negative diplococci and spore-bearing bacilli visible by gram strain and B. fragilis demonstrated by culture, if present in the cervical specimens obtaineduring labor, should be considered abnormal.
The antimicrobial effect of amniotic fluid (AF) obtained during the first (AF1) and second (AF2) trimesters was compared with the third (AF3) against anaerobic bacteria, such as Bacteroides fragilis ss. fragilis (6 strains), Eubacterium lentum (3 strains), and Peptostreptococcus anaerobius (4 strains). Escherichia coli (5 strains) served as a positive control. AF1 supported the growth of all 4 anaerobes (except B fragilis for 4 hours) for the entire 24-hour period tested. AF2 supported the growth of E coli and B fragilis for 24 hours but temporarily inhibited P anaerobius and E lentum. In contrast, AF3 inhibited all bacteria tested for 8 hours or more. It is concluded that AF1 is the least inhibitory, AF3 the most, and AF2 intermediate for the organisms tested. Lack of antimicrobial effect of AF on anaerobic bacteria may be one explanation for the higher incidence of anaerobic infections during absortion than during the prenatal period.
The risk of infections associated with intrauterine fetal monitoring was evaluated in 30 consecutive labors. Amniotic fluid samples collected through the intrauterine catheter were found to be contaminated with bacteria in 15 of 30 consecutively monitored patients during labor. Aerobes were the exclusive isolates in eight, anaerobes in five and both in two patients. Eleven patients developed puerperal fever. One patient developed gonococcal amnionitis, and her newborn infant later developed gonococcal septicemia. The equipment--catheters and fetal scalp electrodes--was sterile. The overall risk of infection associated with internal monitoring in our study was 50% for amniotic fluid contamination and 37% for puerperal febrile morbidity.
Induction of pneumoperitoneum, laparoscopy, and intrauterine endoscopy (fetoscopy) were successfully accompished in 23 pregnant sheep at 45 to 60 days' gestational age. The fetoscope, a conventional 2.7 mm. Hopkins straightforward wide-angle telescope (Stortz 27018A) encased in a prototype 3.1 mm. eccentric cannula, incorporates a 25 gauge needle channel. Multiple pregnancy was encountered in 11 animals. Forty-two separate fetoscopic trials were accomplished; a fetoplacental blood sample was obtained in 52 per cent of the trials. A mean interval of 19 +/- 9 days (+/- S.D., range 6 to 37 days) was allowed between fetoscopy trials. Fetal deaths occurred in nine animals (39 per cent). We believe that laparoscopy permits preselection of the proposed fetoscopy puncture site and will permit the operator to thereby avoid the placenta and/or uterine vessels.
Amniotic fluid samples were obtained at term and tested for their antimicrobial effect on anaerobes, Peptostreptococcus (Ps.) anaerobius, Peptococcus (Pc.) prevotii, Bacteroides (B.) fragilis, and B. coagulans with facultative Escherichia (E.) coli serving as control. Amniotic fluid had only temporary bacteriostatic effect on Pc. prevotii and B. fragilis for 8 to 16 hours. This effect lasted for only 8 hours on Ps. anaerobius. On the contrary, the bacteriostatic effect of amniotic fluid was well sustained on E. coli and B. coagulans, lasting for the entire test periods of 20 and 32 hours, respectively. At the end of the time intervals mentioned, Ps. anaerobius, Pc. prevotii, and B. fragilis exhibited logarithmic growth, confirming the earlier reports that it is not nutritionally deficient. Amniotic fluid exhibited temporary bacteriostatic effect on Ps. anaerobius, P. prevotii, and B. fragilis, but this effect was well sustained against B. coagulans.
The supine hypertensive or 'roll-over' test (ROT) was performed serially in 24 primigravid patients between 27 and 35 weeks of gestational age. Pregnancy-induced hypertension (PIH) developed in 3 women (12.5%). Test producibility one week to the next in the same patient was poor. A false-positive ROT was noted for 83% of our patients a false-negative test for 12.5%. We conclude that serial testing reveals marked variations in response that reflect inherent biologic fluctuations that limit the predictive value of the ROT for screening outpatients.
Twelve patients with either severe preeclampsia (9) or eclampsia (3) were treated with intravenous diazoxide, 300-mg bolus, for the reduction of diastolic blood pressure (less than or equal 110 torr) after the usual and customary measures had been initiated to include parenteral MgSO4 and diazepam. Diazoxide precipitously decreased both systolic and diastolic blood pressure proportionately (35-50%); the nadir was invariably reached in 5-15 minutes. Diastolic pressure never fell below 50 torr, and mean arterial pressure always exceeded 70 torr. Oliguria was not apparent. The vasodepressor response was fairly persistent for 4 hours in all but 3 patients; 2 of these received a second 300-mg dose. Significant changes in fetal heart activity (bradycardia, dysrhythmia) were observed in only 1 patient. Labor was immediately ablated in all patients, but could be restimulated with oxytocin. All pregnancies were terminated within 7 hours (mean, 3.7 hours), seven of them by cesarean section. Eleven newborns did well. We conclude that the immediate reduction in maternal arterial blood pressure is without apparent hazard to the mother as well as the fetus.
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Intrauterine endoscopy (fetoscopy) was successfully accomplished in 26 specially prepared pregnant sheep at 85 to 110 days' gestational age, with the use of a conventional 2.7 mm. Hopkins straightforward wide-angle telescope (Stortz 27018A) encased in a prototype 3.1 mm. eccentric cannula which incorporates a 25 gauge needle channel. Fetal blood was aspirated in 12 lambs. Twenty-five animals were followed throughout the remainder of pregnancy: nine (36 per cent) aborted within three days-three weeks after endoscopy. The pregnant ovine appeared to be a useful experimental animal model for the development of an intrauterine endoscopy technique.
Thirty drug taking and thirty non-drug taking delinquent adolescent girls were assessed using a psychiatric interview technique. Differences were observed between the groups on an aggressive-passive-withdrawn dimension. Drug takers were found to be passive and withdrawn whilst control group subjects were found to be more aggressive. These factors were identified within the modal personality of the delinquent girl. The results supported M.M.P.I. studies of the drug taking personality and were seen as an indication of aetiology and its implications for assessment and treatment.
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Explore the source record for details and available documents.