Io: Evidence for Silicate Volcanism in 1986

Infrared observations of Io during the 1986 apparition of Jupiter indicate that a large eruptive event occurred on the leading side of Io on 7 August 1986, Universal Time. Measurements made at 4.8, 8.7, and 20 micrometers suggest that the source of the event was about 15 kilometers in radius with a model temperature of approximately 900 Kelvin. Together with previously reported events, these measurements indicate that high-temperature volcanic activity on the leading side of Io may be more frequent than previously thought. The inferred temperature is significantly above the boiling point of sulfur in a vacuum(715 Kelvin) and thus constitutes strong evidence for active silicate volcanism on the surface of Io.

PhDs in pediatric departments

A survey on PhDs in academic pediatric departments was sent to members of the Association of Medical School Pediatric Department Chairmen (70% responded). Significant numbers (14.5%) of pediatric faculty members hold PhDs. Another 3.6% hold PhDs/MDs. Research is their major responsibility in every subspecialty except psychology. The majority of PhDs (51%) are assistant professors (8% tenured) in contrast to 37% of MD faculty (14% tenured). The majority of PhDs at full professor (56%) are tenured compared with only 44% of MDs. Separate criteria exist for promotion for PhDs in 42% of departments. For promotion to associate professor, the mean number of refereed publications is 18 (median, 15); for full professor, the number ranges from ten to 50 (median, 40). Extramural research funding carries the highest weight in evaluating research efforts. PhDs could impact significantly on long-range planning in academic pediatric departments.

Spectrogoniometer for measuring planetary surface materials at small phase angles

The surfaces of airless bodies exhibit an anomalous increase in brightness as their faces become fully illuminated to the observer. This opposition effect is generally explained as the disappearance of mutual shadowing among the particles of the optically active portion of the regolith. Models suggest that the regolith's porosity and albedo are the primary factors which determine the effect's amplitude and angular dependence. By using collimated laser light and a pellicle beam splitter, the JPL spectrogoniometer has obtained measurements down to 0 degrees of samples of controlled porosity and albedo. The results of our first measurements show that dark porous surfaces are not the only ones to exhibit large opposition surges. Fits of our measurements to a computer program based on a shadowing model are in good agreement for porous surfaces. In the case of compacted surfaces, the model underpredicts the size of the increase below 3 degrees .

Heparin promotes the inactivation of antithrombin by neutrophil elastase

Heparin is an acceleratory cofactor for antithrombin, a circulating inhibitor of blood coagulation enzymes. The presence of heparin on blood vessel walls is believed to contribute to the nonthrombogenic properties of those surfaces. In apparent opposition to this function, heparin was found to greatly accelerate the in vitro inactivation of antithrombin by neutrophil elastase. Inactivation rates in solution were potentiated several hundredfold by specific heparin fractions with anticoagulant activity. Although the data suggest that a heparin-antithrombin complex is essential for the inactivation by elastase to occur, the enzyme itself interacts tightly with heparin. These results suggest a mechanism which, if operating in vivo, could lead to a localized neutralization of the anticoagulant function of heparin at the endothelial surface.

Developmental intervention for low birth weight infants: improved early development outcome

This prospective longitudinal study was designed to evaluate the effects of a multidisciplinary infant development program (IDP) on the mental and physical development of low birth weight infants (less than 1,800 g). Infants in the neonatal intensive care were randomly assigned to the IDP or to traditional care (control group). IDP infants received developmental interventions in the hospital and at home through the first 2 years of life. Counseling and parenting education were provided to their parents during this same period. The control group received all the postnatal care and referrals customarily given in traditional care. Both IDP and control infants were enrolled in an independent follow-up program, which used the Bayley Scales of Infant Development in a blind evaluation design. The IDP group had a significantly lower incidence of developmental delay (P less than .05) and scored significantly higher than the control group (P less than .05) on mean mental and physical indices at 12 and 24 months of adjusted age.

Intrapartum fetal heart rate patterns and neonatal intraventricular hemorrhage

A goal for the obstetrician and neonatologist is to screen for risk factors associated with intraventricular hemorrhage (IVH) in the low-birthweight infant. Perinatal events that lead to neonatal metabolic and cardiovascular derangements seem to provoke IVH, and conflicting reports have implicated labor as being contributory. A fetal heart rate (FHR) abnormality during premature labor may be a predictor of subsequent neonatal IVH. For this reason, 5 years of FHR tracings at two university medical centers were reviewed for inborn infants who were delivered after premature labor and weighed less than or equal to 2000 gm. Sixty-four infants developed IVH, but pre-existing labor with a discernible FHR pattern was recorded in only 38 (59%) cases. Interpretations were reassuring in 17 (45%) cases, suspicious in 7 (18%) cases, and ominous in 14 (37%) cases. This proportion of FHR patterns was not significantly different from a matched group of premature infants without IVH during the same period. Interpretations of intrapartum FHR patterns of low-birthweight infants are limited, especially before 30 weeks gestation, and not useful in predicting neonatal IVH.

Theophylline treatment in the neonate with apnea: effect on growth hormone, thyroid hormone and TRH induced TSH secretion

Caffeine has been shown to markedly alter growth hormone (GH), thyroid stimulating hormone (TSH), and thyroid hormones in animal studies. Similar studies in the human are lacking. To determine the effect of theophylline treatment on endocrine function in neonates with apnea, 10 infants were studied prospectively pretreatment, immediately following therapeutic blood levels of theophylline, at 2, 4, and 6 weeks thereafter and finally 2 weeks after discontinuation of theophylline. T4, free T4, T3, GH, and basal and stimulated TSH were measured at each study period. Results show no significant difference consequent to theophylline therapy on basal thyroid or GH secretion and thyrotropin-releasing hormone (TRH) induced TSH response at any study interval. We conclude there is no evidence to suspect abnormality occurring in growth, thyroid function and GH secretion in neonates receiving theophylline for breathing disorders.

The economic implications of infection in cardiac surgery

To assess the economic impact of infection, the records of 496 patients aged 18 to 82 years (mean, 61 years) undergoing open-heart operations in 1981 and 1982 were reviewed, and the costs (length of stay, hospital charges, pharmacy charges) were compared for matched pairs of patients with and without infection who had coronary artery bypass grafting (CABG) procedures. Patients received a 5-day regimen of prophylactic cephalosporin. Operative site infections occurred within 6 months of operation in 17 patients (3.4%), urinary tract infections in 9 (1.8%), and pulmonary infections in 6 (1.2%). Early and late mortality was each 2%. No deaths were infection related, and no postoperative bacterial endocarditis occurred (minimum one-year follow-up). For the matched CABG patient in whom a postoperative wound infection developed, the average length of hospital stay was 16.7 days longer and the average hospital bill was $8,118 greater, with the average cost to the hospital $6,605 greater.

Outcome of cardiopulmonary resuscitation in the neonatal intensive care unit

This retrospective review of 83 infants undergoing CPR in the neonatal ICU of a teaching hospital found that 12 (14%) patients were discharged from the hospital and seven (8%) were alive at least 1 yr after discharge. Of these seven, five appeared neurologically intact. From another perspective, 41% (12/29) of the patients who survived at least 24 h after CPR were discharged alive. Factors significantly (p less than .05) associated with poor outcome included sepsis, oliguria 24 h before and/or after arrest, prematurity, and intraventricular hemorrhage. Variables significantly (p less than .05) related to good outcome were the need for intubation during resuscitation and the diagnosis of major congenital anomalies. Intraventricular hemorrhage was the single most powerful variable in the regression analysis. Outcome statistics from this study were strikingly similar to currently available adult data.

Risk of hypoventilation in premature infants in car seats

We examined 30 newborn infants for respiratory compromise before, during, and after placement in a recommended car seat restraining device. Twelve infants were premature with a history of apnea, eight were premature without known apnea, and 10 were born at term. Both premature groups had significant decreases in oxygen saturation while in the car seat (P less than 0.01) and more frequent desaturation episodes less than 80% (P less than 0.001). Premature infants with a history of apnea had more bradycardia events (P less than 0.05). No normal term infant had any of these problems. In addition, oxygen saturation trended downward from baseline for all premature infants during the recovery interval (P = 0.07). We conclude that currently available car seats may place premature infants at risk for significant hypoxia and ventilatory compromise.

Photometry from Voyager 2: Initial Results from the Uranian Atmosphere, Satellites, and Rings

The Voyager 2 photopolarimeter successfully completed the Uranus encounter, acquiring new data on the planet's atmosphere, its principal satellites, and its ring system. Spatially resolved photometry of the atmosphere at 0.27 micrometer shows no enhancement in absorption toward the pole, unlike the case for Jupiter and Saturn. Stellar occultation measurements indicate the temperature at the 1-millibar level over the north pole is near 90 kelvins. The geometric albedos of the five large satellites of Uranus were measured at 0.27 and 0.75 micrometer and indicate the presence of low albedo, spetrally flat absorbing material. Titania seems to have a fluffy surface, as indicated by its phase curve. The nine ground-based rings were detected, and their internal structure, optical depths, and positions were determined. The sharp edges of the in ring made it possible to measure its edge thickness (less than 150 meters) and particle sizes (less than 30 meters); little or no dust was detcted. New narrow rings and partial rings (arcs) were measured, and the narrow component of the eta ring was found to be discontinuous.

Serum concentrations of prostacyclin and thromboxane in children before, during, and after cardiopulmonary bypass

Twenty-six consecutive pediatric patients undergoing reparative procedures necessitating cardiopulmonary bypass were prospectively studied to determine changes in serum levels of 6-keto-prostaglandin F1 alpha and thromboxane B2. Cardiac lesions included acyanotic lesions (five patients), obstructive lesions (10 patients), and right-to-left shunts (11 patients). There was a significant (p less than 0.05) increase in 6-keto-prostaglandin F1 alpha from preoperative levels measured at the time of arterial and venous cannula insertion. This concentration was maintained throughout cardiopulmonary bypass and remained significantly elevated (p less than 0.001) in the recovery room, but returned to preoperative levels by the morning after the operation. Preoperative levels of thromboxane B2 varied widely and were not significantly different from intraoperative levels. The postoperative levels of thromboxane B2, however, were significantly different (p less than 0.05) from the intraoperative levels. In the pediatric age group undergoing cardiopulmonary bypass, 6-keto-prostaglandin F1 alpha and thromboxane B2 change during bypass but do not significantly differ when preoperative levels are compared to postoperative values.

Telencephalic microvessels of premature beagle pups

The ultrastructural morphologic and morphometric characteristics of the telencephalic microvasculature of both germinal matrix and border-zone cerebral cortex are analyzed from premature beagle puppies delivered by caesarean section in order to determine whether differences in the matrical vessels could account for their susceptibility to intraventricular hemorrhage. The germinal matrix microvessels are immature, since they contain intraluminal microvilli and junctional complexes (primarily tight junctions) that are not continuous between the lateral endothelial cell walls. The number of junctional complexes per vessel cross-section is less than either cortical vessels from the same premature animals or tissue from either site in full-term animals. Morphometric data on the cross-sectional area of vessels from the two sites indicate that the germinal matrix vessels have a significantly larger cross-sectional area than the cortical vessels. The increase is due almost exclusively to a larger endothelial cell area per cross section. This pattern is an altogether different one from that seen in the term animals. There the germinal matrix vessels exhibit a steadily decreasing luminal area from birth through 72 hr, whereas endothelial cell cross-sectional area is static. Here the luminal cross-sectional area is smaller, but both endothelial cell and total vessel cross-sectional areas are significantly larger. Structural components of the blood-brain barrier undergo active modifications during the late prenatal period that are distinct from the modifications during the immediate postnatal period.

Coronary bypass surgery early after thrombolytic therapy for acute myocardial infarction

The safety of coronary bypass operations after coronary reperfusion with streptokinase for acute myocardial infarction is not well documented. Therefore we studied 23 consecutive patients (mean age, 59.5 years; 22 men) undergoing bypass operations a median of 5 days (range, 1 to 23 days) after thrombolysis (streptokinase). The control group consisted of 169 concurrent patients of similar mean age (58.8 years) having bypass operations for standard indications. The preoperative angiographic ejection fraction was 68 +/- 14% in the control patients and 61 +/- 14% in the streptokinase group (p less than 0.05). The number of diseased vessels (70% stenosis or greater) averaged 2.6 in control and 2.3 in streptokinase patients. A previous myocardial infarction had occurred in 42% of the controls and all of the streptokinase patients. Aortic cross-clamp times did not differ between the two groups (80 +/- 35 minutes for the controls and 68 +/- 25 minutes for the streptokinase group). Cardiopulmonary bypass times were similar: 108 +/- 45 minutes in the controls versus 109 +/- 28 minutes in the streptokinase group. Grafts per patient averaged 3.7 +/- 1.5 for the controls versus 2.8 +/- 1.1 for the streptokinase patients (p less than 0.01). Difficult operative hemostasis was noted in 4% of both groups. Inotropic support was given postoperatively to 11% of the control and 13% of the streptokinase patients (p = not significant). Measured blood loss during the first 48 hours postoperatively was similar, averaging 809 ml in controls and 776 ml in the streptokinase group. Blood product replacement was also comparable: mean, 713 ml in the control group versus 759 ml in the streptokinase group.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood loss at vaginal delivery

Although the accurate assessment of blood loss at vaginal delivery is clinically important in terms of maternal morbidity and mortality, the quantity is usually underestimated. We present a simple, practical, and convenient method of quantitating blood loss at vaginal delivery. The method of vaginal delivery (spontaneous versus forceps) does not significantly affect blood loss; an episiotomy, a laceration, or both may.

Fetal response decrement: true habituation?

Preliminary evidence suggests that fetal movement in response to vibrotactile stimulation "habituates" with repeated exposure. If demonstrated in fetuses, the habituation paradigm may be useful as a measure of fetal well-being or as a predictor of neonatal outcome. However, the ability of the fetal response decrement phenomenon to meet criteria for habituation which would distinguish it from simple receptor fatigue has not been evaluated. In this study, fetuses were exposed to two different frequencies of vibration applied to the maternal abdomen. Fetal movement was observed on an ultrasound monitor. An inverse relationship between the strength of the stimulus and rapidity of the response decrement was not observed. However, return of the response to presentation of a novel stimulus, response decrement to repetition of the second stimulus, and more rapid response decrement upon re-presentation of the original stimulus suggest that the fetal response decrement phenomenon is true habituation.

Single-antibiotic use for penetrating abdominal trauma

A prospective randomized study compared the use of moxalactam disodium vs clindamycin phosphate and tobramycin sulfate for treatment of 190 patients with penetrating abdominal trauma. Twenty-seven patients were disqualified because of early death or failure to follow the protocol. The patients in each group were comparable regarding the cause and severity of injury. No significant difference was seen in the incidence of intra-abdominal infection between the moxalactam-treated group (13%) and the clindamycin- and tobramycin-treated group (9%). The intra-abdominal infection rate in patients with colon injuries (21%) was significantly increased when compared with the patients without colon injuries (6%), but the antibiotic regimen did not significantly change the infection rate. No evidence of bleeding problems from moxalactam were noted. Changes in prothrombin and partial thromboplastin times appeared to be related to shock rather than the use of moxalactam. The most severe coagulopathies occurred prior to moxalactam therapy and were seen only in those patients who had shock requiring 10 or more units of blood. Moxalactam is as effective as combination (clindamycin and tobramycin) antimicrobial therapy in patients with penetrating abdominal trauma.

Antenatal prediction of sex

Current recommendations suggest that prospective parents be informed of the fetal sex following an amniocentesis--if the parents express a desire for that information. Genotype does not in all cases accurately predict the appropriate sex of rearing. A case is discussed involving an infant with ambiguous genitalia who prior to birth had been designated a male, based on genotype obtained following amniocentesis. Caution is urged in predicting sex antenatally.

Rhabdomyolysis and myoglobinemia in neonates

Serial myoglobin determinations were made in 20 neonates during the first week of life to determine whether birth asphyxia results in ischemic damage to muscle with the subsequent pathologic release of myoglobin. Serum myoglobin values were significantly elevated in asphyxiated infants compared with control infants. High myoglobin values correlated with a longer duration of oliguria in the neonatal intensive care unit population. The value of urine dipstick testing for myoglobinuria screening was also evaluated. Infants with elevated myoglobin values were more likely to have a strongly positive urine dipstick for occult blood in the first 48 hours of life. These data suggest that ischemic damage to muscle with pathologic release of myoglobin occurs in the neonatal period and that urine dipstick testing provides a reasonable screening examination for myoglobinuria.