Where Biology and Traditional Polymers Meet: The Potential of Associating Sequence-Defined Polymers for Materials Science

Polymers with precisely defined monomeric sequences present an exquisite tool for controlling material properties by harnessing both the robustness of synthetic polymers and the ability to tailor the inter- and intramolecular interactions so crucial to many biological materials. While polymer scientists traditionally synthesized and studied the physics of long molecules best described by their statistical nature, many biological polymers derive their highly tailored functions from precisely controlled sequences. Therefore, significant effort has been applied toward developing new methods of synthesizing, characterizing, and understanding the physics of non-natural sequence-defined polymers. This perspective considers the synergistic advantages that can be achieved via tailoring both precise sequence control and attributes of traditional polymers in a single system. Here, we focus on the potential of sequence-defined polymers in highly associating systems, with a focus on the unique properties, such as enhanced proton conductivity, that can be attained by incorporating sequence. In particular, we examine these materials as key model systems for studying previously unresolvable questions in polymer physics including the role of chain shape near interfaces and how to tailor compatibilization between dissimilar polymer blocks. Finally, we discuss the critical challenges-in particular, truly scalable synthetic approaches, characterization and modeling tools, and robust control and understanding of assembly pathways-that must be overcome for sequence-defined polymers to attain their potential and achieve ubiquity.

3D Printable and Reconfigurable Liquid Crystal Elastomers with Light-Induced Shape Memory via Dynamic Bond Exchange

3D printable and reconfigurable liquid crystal elastomers (LCEs) that reversibly shape-morph when cycled above and below their nematic-to-isotropic transition temperature (T_NI ) are created, whose actuated shape can be locked-in via high-temperature UV exposure. By synthesizing LCE-based inks with light-triggerable dynamic bonds, printing can be harnessed to locally program their director alignment and UV light can be used to enable controlled network reconfiguration without requiring an imposed mechanical field. Using this integrated approach, 3D LCEs are constructed in both monolithic and heterogenous layouts that exhibit complex shape changes, and whose transformed shapes could be locked-in on demand.

Absence of Electrostatic Rigidity in Conjugated Polyelectrolytes with Pendant Charges

The delocalization of electrons in conjugated polymers impacts their chain shape, affecting their local ordering, self-assembly, and ultimately charge transport. Conjugated polyelectrolytes introduce electrostatic interactions as a molecular design parameter to potentially tune chain rigidity by combining the π-conjugated polymer backbone with pendant ionic groups. In conventional polyelectrolytes, the self-repulsion of the bound charges induce extended rod-like chain configurations. Here, we leverage small-angle neutron scattering to measure the chain shapes of model conjugated polymers in dilute solution with controlled fractions of randomly distributed pendant charges. We find these model polythiophenes are semiflexible, with a persistence length of approximately 3 nm, regardless of charge fraction, suggesting the effective absence of electrostatic rigidity in conjugated polyelectrolytes. While the overall persistence length is negligibly impacted by pendant charges, optical spectroscopy indicates that the pendant charges increase the backbone torsion between thiophene rings without significantly impacting the π-conjugation length (the length of electron delocalization along a nearly planar backbone) in dilute solution. These results indicate the effective decoupling of the pendant ionic charges from the overall chain conformation with implications for solution processing of organic semiconductors.

Untethered soft robotic matter with passive control of shape morphing and propulsion

There is growing interest in creating untethered soft robotic matter that can repeatedly shape-morph and self-propel in response to external stimuli. Toward this goal, we printed soft robotic matter composed of liquid crystal elastomer (LCE) bilayers with orthogonal director alignment and different nematic-to-isotropic transition temperatures (T _NI) to form active hinges that interconnect polymeric tiles. When heated above their respective actuation temperatures, the printed LCE hinges exhibit a large, reversible bending response. Their actuation response is programmed by varying their chemistry and printed architecture. Through an integrated design and additive manufacturing approach, we created passively controlled, untethered soft robotic matter that adopts task-specific configurations on demand, including a self-twisting origami polyhedron that exhibits three stable configurations and a "rollbot" that assembles into a pentagonal prism and self-rolls in programmed responses to thermal stimuli.

Branched Side Chains Govern Counterion Position and Doping Mechanism in Conjugated Polythiophenes

Predicting the interactions between a semiconducting polymer and dopant is not straightforward due to the intrinsic structural and energetic disorder in polymeric systems. Although the driving force for efficient charge transfer depends on a favorable offset between the electron donor and acceptor, we demonstrate that the efficacy of doping also relies on structural constraints of incorporating a dopant molecule into the semiconducting polymer film. Here, we report the evolution in spectroscopic and electrical properties of a model conjugated polymer upon exposure to two dopant types: one that directly oxidizes the polymeric backbone and one that protonates the polymer backbone. Through vapor phase infiltration, the common charge transfer dopant, F₄-TCNQ, forms a charge transfer complex (CTC) with the polymer poly(3-(2'-ethyl)hexylthiophene) (P3EHT), a conjugated polymer with the same backbone as the well-characterized polymer P3HT, resulting in a maximum electrical conductivity of 3 × 10^-5 S cm^-1. We postulate that the branched side chains of P3EHT force F₄-TCNQ to reside between the π-faces of the crystallites, resulting in partial charge transfer between the donor and the acceptor. Conversely, protonation of the polymeric backbone using the strong acid, HTFSI, increases the electrical conductivity of P3EHT to a maximum of 4 × 10^-3 S cm^-1, 2 orders of magnitude higher than when a charge transfer dopant is used. The ability for the backbone of P3EHT to be protonated by an acid dopant, but not oxidized directly by F₄-TCNQ, suggests that steric hindrance plays a significant role in the degree of charge transfer between dopant and polymer, even when the driving force for charge transfer is sufficient.

Enhanced Water Vapor Blocking in Transparent Hybrid Polymer-Nanocrystal Films

Highly transparent and effective encapsulating materials have become increasingly important for photovoltaic (PV) modules to prevent water vapor molecules from permeating PV cells. The composite consists of block copolymer (PS-b-P2VP), comprised of hydrophobic and hydrophilic parts, and hygroscopic nanocrystals (Magnesium Oxide, MgO) incorporated to enhance water vapor blocking by both presenting obstacles for mass transport and also scavenging water molecules. The water vapor transmission rate (WVTR) values were reduced ∼3000 times, compared to homopolymer (PS), for both polymer and composite samples. Achieving both high transparency and low WVTR, it is expected that the composite materials can function as an excellent water vapor blocking layer for PV modules.

Preventing perinatal transmission of human immunodeficiency virus in the United States. Committee on Perinatal Transmission of HIV

Prenatal human immunodeficiency virus (HIV) testing and treatment instituted in the 1990s is responsible for a substantial reduction in the number of children diagnosed with AIDS, yet the number of children born with HIV infection remains unacceptably high. To prevent perinatal transmission of HIV, the United States must adopt a goal to test all pregnant women for HIV and to provide optimal treatment for women who test positive and their children. To meet this goal, the United States should adopt a national policy of universal HIV testing with patient notification as a routine component of prenatal care. Adopting this policy will require the establishment of, and resources for, a comprehensive infrastructure. This infrastructure must include education of prenatal care providers, the development and implementation of practice guidelines and the implementation of clinical policies, the development and adoption of performance measures and Medicaid managed care contract language for prenatal HIV testing, efforts to improve coordination of care and access to high-quality HIV treatment, interventions to overcome pregnant women's concerns about HIV testing and treatment, and efforts to increase use of prenatal care, as described above.

Temperature Regulation of Supercooling and Gut Nucleation in Relation to Diapause of Pyrrhocoris apterus (L.) (Heteroptera)

The heteropteran Pyrrhocoris apterus (L.) does not survive freezing of its body fluids; there is a good correlation between values of survival at subzero temperatures and the supercooling point (SCP), i.e., the temperature at which body fluids start to freeze. The decrease of the SCP and thus the increase in cold hardiness is regulated by photoperiod and temperature. The relative importance of these factors depends on the physiological state of the insect. The SCP is about -7°C at the onset of prediapause and a decrease of about 4-5°C is associated with the development of the diapause syndrome in adults; these processes both are induced by a short-day photoperiod with temperature playing a secondary role. The induction of the diapause syndrome is a prerequisite for the subsequent decrease of the SCP by about 5-6°C during cold acclimation. An intermediate temperature of 15°C, or fluctuating outdoor temperatures and short-day photoperiods, are more suitable for the decrease of SCP than 5°C in continuous darkness. The sensitivity to photoperiod gradually disappears during the development of diapause; after the termination of diapause around the winter solstice the SCP irreversibly increases at a high temperature of 26°C even if exposed to a short-day photoperiod. The SCPs of hemolymph, gut, fat body, and gonads were compared to whole-body SCP. The gut was identified as the primary site of ice nucleation because its SCP value was very similar to the value for the whole body in both short-day and long-day insects. The SCPs of other organs, including the hemolymph, were always lower than the whole body SCP. Food was not a source of ice nucleating agents because the SCP of freshly ecdysed adults remained high after 2 weeks of starvation. In contrast, feeding was a prerequisite for the decrease of the SCP during prediapause. In postdiapause insects, the SCP increased at high temperatures in spite of the absence of food.

Formal resident training in urogynecology and pelvic floor disorders. A six-year survey

An observational study reviewed the efficacy of resident training in urogynecology and pelvic floor disorders. After instituting a formal urogynecology rotation consisting of two one-month rotations in the second and third years at a major inner city county hospital, 24 residents were prospectively followed to assess their cognitive and clinical skills, including endoscopic, urodynamic and surgical competence. They were evaluated by objective testing and close observation. The results showed 41.875% (+/- 16.669 SD) entry level objective correct answers as compared to 82.083% (+/- 10.206) upon completion of the rotation. Residents were observed and graded over the six-year period by one (occasionally two) faculty members for successful task completion. The residents' mastery of surgical, endoscopic and urodynamic skills was deemed acceptable through a subjective evaluation by urogynecology faculty members based on satisfactory completion of 80% of the assigned task. Formal urogynecologic training by a knowledgeable subspecialist is a useful adjunct to the obstetrics-and-gynecology residency program.

Sociologic aspects of pregnancy

Increasingly, social factors are recognized as having a major impact on pregnancy, childbearing, and prenatal care. This review examines some of the more recent societal developments that have influenced health care for pregnant women. Although human gestation is a biologic phenomena, it exists with the social context of personal needs, family, and community of the pregnant women. This social fabric determines the perception, management, and outcome of that gestation. Significant influences to examine include pregnant women in the work force; malpractice concerns of health care providers; issues related to the cost of health care in pregnancy; the legal rights of the pregnant woman versus the legal rights of the fetus; pregnancy and occupational health; and the role of stress in pregnancy outcome.

Peripheral pulse pressure patterns in pregnancy hypertension

Maternal heart rate and pulse pressure patterns were examined in 30 hypertensive pregnant women using noninvasive methodology described previously. "Narrow" and "wide" pulse patterns were identified. Narrow cutaneous pulse pressure patterns, which are thought to be caused by vasoconstriction, were associated with lower birth weight infants (1870 +/- 983 versus 3225 +/- 838 g; P less than .001) and earlier deliveries (34.2 +/- 5.2 versus 37.9 +/- 2.8 weeks; P less than .05). The data suggest that these adjunctive maternal cardiovascular-system evaluation techniques may be useful in identifying patients at risk of adverse perinatal outcome by detecting vasospasm of the peripheral microcirculation.

The challenge of care for the poor and underserved in the United States. An American College of Obstetricians and Gynecologists perspective on access to care for underserved women

Access to pregnancy-related care for women and their infants and to reproductive health services for adolescents are significant concerns to the American College of Obstetricians and Gynecologists (ACOG). Adolescent and young adult women are among those most likely to be uninsured and lack access to health care services. Adolescent pregnancy, low-birth weight, and infant mortality remain major national burdens. The ACOG has taken the position that quality health care should be accessible to all women. The ACOG recommendations regarding health services for adolescents and the ACOG Committee on Health Care for Underserved Women's statement of principles regarding universal access for pregnancy-related care, which includes the basic scope of benefits, the characteristics of the providers, and the organization of services are described.

A strategy to reduce infant mortality

Using maternal mortality reviews as an historic model, fetal and infant mortality reviews are proposed to reduce infant mortality in the United States. The national program has three elements: 1) guidelines and direction from a national multidisciplinary steering panel and staff, 2) a technical advisory capacity to translate guidelines and to work with local and regional review committees, and 3) local review committees. A special emphasis, lacking in the limited efforts of previous infant mortality reviews, would be given to fetal mortality. The plan proposes a broad classification of potential contributing causes of mortality, from those related strictly to medical care, to the health system, and to individual patient factors. This will allow different and more effective targeted responses to factors identified locally. Critical impetus will be gained with The American College of Obstetricians and Gynecologists leading the effort from the private medical sector in partnership with national, state, and local public health agencies and other national medical societies.

A beltless tocodynamometer--a preliminary report

The clinical usefulness of a newly developed beltless external tocodynamometer system was evaluated in a group of 56 patients in active, early, premature, or false labor. The uterine activity records so obtained were compared with those made in the same patients using the tocodynamometer with belt (49 patients) and the intrauterine pressure catheter (seven patients). The records were classified as "usable" if the baseline was above zero and the peak of the recorded contraction was at least 15 mmHg above the baseline. Both systems were studied under similar clinical conditions. Overall, of the 7434 minutes of recordings in 49 patients using the beltless system, 7008 minutes (94%) were usable. In contrast, only 2515 out of 5667 minutes (45%) of recordings made with the belted system were usable (P less than .001). Seven additional patients were monitored simultaneously with the beltless tocodynamometer and the intrauterine pressure catheter systems. Of the 1367 minutes' total monitoring time, the recovery rates of usable data for the beltless and intrauterine pressure catheter systems were 85 and 87%, respectively (P = not significant). These preliminary results indicate that the beltless system is a convenient, simple-to-use external tocodynamometric system that assesses uterine activity more efficiently than the belted system.

Limitations of autocorrelation in fetal heart rate monitoring

Fetal heart rate monitors that use autocorrelation of the ultrasonic fetal signal usually produce a cleaner fetal heart rate record than that obtainable with conventional ultrasonic fetal monitors. However, since the autocorrelation function will emphasize any periodic signal originating from the fetus or the mother, in clinical situations the resultant fetal heart rate tracing may contain spurious data. To illustrate the limitations of the autocorrelation technique in fetal monitoring, we compared the autocorrelated ultrasound fetal heart rate records from 23 patients in active labor with the simultaneously recorded direct scalp fetal electrocardiogram tracings. The results indicate that every hour of recording contained, on the average, five instances in which data were missing (range, 0 to 13), four in which data were added (range, 0 to 23), and seven instances in which data were absent for greater than 1 minute (range, 0 to 26). The potential problem of misinterpretation of autocorrelated fetal heart rate data is discussed.

The age extremes for reproduction: current implications for policy change

The changing demographic features of births in the United States include an increasing number of older women and a decreasing number of adolescents giving birth. Births in adolescents have lower risks than those in women more than 34 years of age and probably of those more than 30 years of age. There is an increase in complicated pregnancies in the United States, related, no doubt in part, to the above. Older women require more costly, high-technology prenatal care, such as genetic counseling, genetic antenatal diagnosis, amniocentesis, ultrasonography, and electronic fetal heart rate testing. The financing of health care needs to recognize these changes. Detailed studies of the economics of perinatal care, more specific to patient population mix and complication-treatment patterns are needed to establish priorities with the payment system to assure appropriate care.

Trends in obstetric-gynecologic academic manpower--1983

Since 1980 medical school faculty growth has essentially ceased, in comparison to earlier substantial increases. Women are represented in full-time faculty positions in a larger proportion than among practicing obstetrician-gynecologists. Subspecialist numbers on faculties have increased, with a small decline in generalist obstetrician-gynecologists. Despite the current plateau, medical school departments project a 36% increase in faculty members during the next five years, and an even larger increase in faculty involved in research.

Minocycline prophylaxis in elective hysterectomy

Minocycline prophylaxis was compared with a placebo in 126 consecutive patients undergoing hysterectomy. The double-blind nature of this study was guarded until the study was completed. Of 95 patients who had abdominal hysterectomies, 32.7% on minocycline and 39.1% on placebo developed infectious complications. Of 31 vaginal hysterectomy patients, 20% on minocycline and 37.5% on the placebo developed septic complications (p less than 0.05). Although minocycline inhibited B. fragilis and E. coli effectively, those organisms colonized increasingly during the postoperative period with similar frequency in both the minocycline- and placebo-treated groups. Minocycline did not produce antibiotic-resistant strains. In our study the parenteral and oral forms of minocycline were found to be safe, and vestibular symptoms were no more common than in the placebo group. These data suggest that antibiotic prophylaxis with minocycline is safe and well tolerated. In addition, minocycline is effective in lowering the infection rate in vaginal, but not abdominal, hysterectomies.

Cyclic changes in cervical microflora and their effect on infections following hysterectomy

In a prospective study the cyclic changes in the cervical microflora and the endometrial histology were correlated with the incidence of postoperative infections in 99 women undergoing elective abdominal hysterectomy. Escherichia coli and Bacteroides fragilis were isolated more frequently during the proliferative phase than during the secretory phase and, correspondingly, postoperative infections were more frequent when operated during the proliferative phase than during the secretory phase. Moderate to severe infections occurred in 31.6% of the patients operated during the proliferative phase in contrast to 18% during the secretory phase. This suggests increased host susceptibility to infection during the proliferative phase.

Tuberculosis presenting as a pelvis mass

Tuberculosis is one of the world's most important communicable diseases. Although it may involve the genital tract and frequently results in infertility, the presentation of the disease as a pelvic mass is uncommon. While the incidence of tuberculosis has declined in the United States, genital tuberculosis should be considered in patients presenting with adnexal mass and a history of infertility. One such case is presented here, and diagnosis and treatment are described.

An analysis of adolescent health care and the role of the obstetrician-gynecologist

There has been documented an increase in sexual activity in adolescents in the United States and a resultant increase in related health care for pregnancy, abortion, contraception, and sexually transmitted disease. This study characterizes some elements of these services and the attitudes of physicians in regard to adolescent sexuality. The Female Datafile from the University of Southern California--Mendenhall Manpower Study and the survey of the American College of Obstetricians and Gynecologists on adolescent pregnancy suggest that obstetrician-gynecologists provide a large portion of health care to both adult (14.6%) and adolescent women (7.7%); that reproductive health care is primarily provided by obstetrician-gynecologists to female adolescents (76%); that adolescent care is generally less comprehensive in private practice than is recommended; that obstetrician-gynecologists could be the primary care physicians for both adult and adolescent women, since they are increasingly the medical contact point, especially after age 14; and, in view of the negative attitudes of physicians to adolescent sexual practices, that some training or reorientation will probably be necessary to prevent judgmental approaches from interfering with the physician-adolescent patient relationship.

Sampling the fetoplacental circulation. IV. Preliminary experience in the pregnant baboon (Papio cynocephalus)

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.

Sampling the fetoplacental circulation. III. Combined laparoscopy-fetoscopy in the pregnant macaque for hemoglobin identification

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.

Cesarean delivery in a gorilla

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.

Antimicrobial effect of amniotic fluid

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.

Microflora of the cervix during normal labor and the puerperium

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.

Vascular reactivity to angiotensin II infusion during gestation

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.

Amniotic fluid contamination during internal fetal monitoring

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.

Sampling the fetoplacental circulation. II. Combined laparoscopy-fetoscopy in the pregnant ovine

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.

The management of severe preeclampsia and eclampsia with intravenous diazoxide

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.

Antimicrobial effect of amniotic fluid against anaerobic bacteria

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.

Sequential evaluation of the supine hypertension or 'roll-over' test in a high risk population

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.

Sampling the fetoplacental circulation. I. The pregnant ovine

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.

Juvenile delinquent drug abuse in females: a clinical study

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.