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Biomedical subjects

H Cohen

Publications and source records attributed to H Cohen.

At least 541 records · Page 30Linked to original sources
PubMed1977

Respiratory depression at birth--value of Apgar score and ventilatory measurements in its detection.

The purpose of this investigation was to determine the value of ventilatory measurements and Apgar score in the diagnosis of respiratory depression in the newborn infant. The following were the results of the determinations made in 24 neonates whose mothers had received meperidine in a total dose up to 3 mg/kg within three hours prior to delivery; Respiratory rate, 51+/-3.7/minute; tidal volume, 21.4 +/- 1.5 ml; minute ventilation, 339 +/- 24 ml/kg X minute; end tidal CO2, 40.8 +/- 1.3 mm Hg; ventilatory response to CO2, 21.8 +/- 2.7 ML/KG X minute X mm Hg PACO2. The mean Apgar score was 7.1 and 9.0 at 1 and 5 minutes, respectively. None of the determinations were indicative of respiratory depression with the exception of the slope of the CO2 response curve; it was considered to be below the normal range. No correlations existed between the CO2 response curve and any other values. It is concluded that meperidine administered to mothers in labor in the described dose will not significantly alter Apgar score, VE, VT, RR, AND PAco2 in the newborn infant. The extent of respiratory center depression could be determined only by the decreased ventilatory response to CO2.

Apgar Score↗
PubMed1977

Use of nalotone to to reverse narcotic respiratory depression in the newborn infant.

Twenty neonates whose mothers had received meperidine (1.0 to 1.5 mg/kg) intravenously within three hours of delivery were studied to determine the effectiveness of naloxone in reversing neonatal respiratory depression. The following measurements were carried out within 20 to 30 minutes after delivery: minute ventilation, end tidal CO2, and ventilatory response to CO2. These determinations were repeated after administration of either placebo or naloxone, 0.01 mg/kg intramuscularly. Minute ventilation and PAco were within a normal range before medication in both groups, but the slope of the CO2 response curve was decreased, indicating mild-to-moderate respiratory depression. After administration of placebo the test results did not change significantly. After administration of naloxone, VE increased significantly (P less than 0.05) and the slope of the CO2 response curve doubled (P less than 0.001). Naloxone effectively reverses narcotic depression of the respiratory center in the newborn infant.

Carbon Dioxide↗
PubMed1977

Behavioral effects of interinstitutional relocation of mentally retarded residents.

Deinstitutionalization requires relocation of mentally residents. An exploratory investigation was conducted of the impact of interinstitutional relocation. The subjects were residents transferred from a large institution to a smaller facility and a matched comparison group from the latter facility. The 92 male and female subjects ranged from 10 to 42 years of age. The Adaptive Behavior Scale was administered prior to relocation, immediately following relocation, and 6 to 8 weeks following relocation. Higher functioning residents showed a pattern of lowered functioning and withdrawal following relocation. Relative to the comparison group, they were more withdrawn and suffered setbacks in language development. In contrast, lower functioning residents generally increased activity levels of both adaptive and acting-out behavior. The necessity for risk/benefit analysis preceding decisions to relocate residents was discussed.

Adaptation, Psychological↗
PubMed1976

[Half-life of dehydroepiandrosterone sulfate (DHAS) during pregnancy].

During pregnancy the half-life of DHAS was measured after non tritiated DHAS infusion. At 30 weeks, the mean value obtained for DHAS half-life was 3.64 h +/- 0.74 and it was 3.67h +/- 0.38 at 38 weeks. The half-life of DHAS is shorter in pregnant than in non-pregnant women. Among 14 pathological pregnancies that we studied, 13 cases exhibited a DHAS half-life significantly longer than the average value obtained in normal pregnancies. In retarded fetal growth, the half-life of DHAS was more closely related to fetal than to placental weight.

Anencephaly↗
PubMed1976

Effects of sleep of restricted sleep. A cat case study.

One male cat was adapted to different schedules of restricted sleep. The cat was allowed to go to sleep during a certain number of hours per day. During the rest of the 24 h period, wakefulness was enforced by means of a treadmill. The following schedules of restricted sleep were run: 12 h sleep--12 h treadmill (12S--12T), 8S--16T, 4S--20T. The cat was also adapted to a 36 h day: 12S--24T. The sleep was investigated after at least 2 weeks on each schedule and compared to ad lib. sleep (24S--0T). As available sleep time bacame shorter, the composition of the sleep changed. LSWS (in % of available sleep time) decreased, while DSWS % and REM sleep % increased. The length of the DSWS and REM sleep episodes increased with decreasing sleep time, as did sleep cycle length.

Animals↗
PubMed1976

MaD, an automated precise analytical ultracentrifuge scanner system.

The various hardware components of this scanning system, a mechanical split-beam scanner with its photomultiplier measuring slit, minimum analog electronics and an important digital part (computer, interface), are intimately interwoven by an elaborate software. A high degree of automation and sophistication is thus reached. On the one hand, all the photoelectrons coming from each light pulse are integrated. The result, after conversion to digital form enters the computer; a high precision is thus reached: 10(-5) absorbance unit (A.U.) under very favorable conditions, and 10(-4) A.U. for conventional sedimentation studies. On the other hand, during its motion along the image, the precise slit position is permanently known by the system: the sector image is thus segmented into precisely defined zones, inside which the average absorbancies are determined, punched, plotted and printed. New and very useful utilizations and improvements of analytical ultracentrifugation are now possible: the fixed radius mode, permits precise s determination by following the radial dilution; s can be precisely measured by time difference curves even when the solution absorbancy is comparable to the base line variations (0.01 A.U.); round trip analyses permit very long analyses without the absorbancies distributions distorsions due to very long one-way scans during sedimentations runs; reductions of the effect of the stray light by a factor of ten. This system has been in routine use for four years.

Autoanalysis↗
PubMed1976

The hemodynamic effects of intrauterine hypoxia: an experimental model in newborn lambs.

An experimental animal model of intrauterine hypoxia and respiratory distress in newborn lambs was produced by inducing maternal hypotension. Serial hemodynamic data indicated that the oxygenation defect in the lambs was due to right-to-left shunting of blood through fetal channels rather than within the lungs. Shunting was mainly across the foramen ovale, but, in severely distressed animals, significant right-to-left shunt also occurred through the ductus arteriosus. Left-to-right shunts across the ductus arteriosus were found in lambs with milder respiratory distress. The implications of perinatal hypoxia as it affects the pulmonary vascular bed in human neonates with the respiratory distress syndrome (hyaline membrane disease) and persistence of the fetal circulation are discussed. It is speculated that the early pulmonary vascular esponses in the two diseases may be identical.

Animals↗
PubMed1976

Iron mobilization in the pregnant rat.

Iron exchange in the pregnant rat was quantitated by repeated determinations of plasma iron turnover (PIT), transferrin iron distribution and measurements of storage iron and food iron utilization employing selective radio-iron probes. Despite a sixfold increase in PIT, intestinal absorption of iron accounted for 40% of the PIT throughout pregnancy, with variations not exceeding +/- 5%. Increased fetal requirements were efficiently compensated for by the mobilization of iron from maternal tissue stores and by increased absorption, and there was no subsequent reduction in iron supply to maternal tissues. Enhancement of iron absorption occurred in the absence of a reduction in serum iron levels or the size of iron stores. In view of the close correlation between PIT and rates of absorption it is postulated that iron absorption in the pregnant rat is regulated by PIT which in turn is determined by the rate of plasma iron clearance by the placenta and the maternal erythroid marrow.

Animals↗
PubMed1976

Dominant ichthyosis vulgaris with an ultrastructurally normal granular layer.

It has been suggested that ultrastructural studies of keratohyalin granules in the granular layer of the skin can clearly distinguish the dominant type from the X-linked recessive type of ichthyosis vulgaris. The distinctive features are found in the granular layer and the keratohyalin granules. In the dominant form the granular layer is absent or reduced in size and the keratohyalin granules are minute and crumbly in appearance. In the recessive form the granular layer and keratohyalin granules are normal. A family which probably has dominant ichthyosis vulgaris is described. The stratum granulosum and keratohyalin granules as determined by both light and electron microscopy are normal. In view of the inconstant morphologic appearance of the stratum granulosum in ichthyosis vulgaris, it is suggested that distinction between the dominant and X-linked forms should not be based on the structural characteristics of the granular layer alone, but rather on a combined evaluation of the pedigree, clinical features and the appearance of the stratum granulosum.

Adolescent↗
PubMed1976

Cardiac and pulmonary failure secondary to adenotonsillar hypertrophy.

For over 15 years, upper respiratory tract obstruction due to adenotonsillar hypertrophy has been known to cause hypoxia, hypercapnia, increased pulmonary vascular resistance and thereby cor pulmonale and congestive heart failure. This is now an uncommon but not rare entity and three recent cases prompted this report. The typical patient is dyspneic with retractions, cyanosis, occasional periods of apnea and somnolence. Edema and hepatomegaly and at times splenomegaly are common. X-rays show cardiomegaly, which on electrocardiogram is found to involved mainly the right ventricle. The strict definition of cor pulmonale is right ventricular hypertrophy secondary to lung disease or abnormal pulmonary function, a definition that may logically be stretched to include abnormal respiratory function secondary to upper airway pathology. The mechanisms by which this occurs are generally agreed upon. Hypoxia has been demonstrated to cause pulmonary vasoconstriction. Acidosis and hypercapnia are thought by some to have the same effect. Pressure across the pulmonary vascular bed is also increased, as predicted by Poiseuille's law, by the high rate of blood flow required to maintain tissue oxygenation with poorly oxygenated blood. Conditions producing hypoxia of hypercapnia or both lead to hypertrophy and eventually to dilatation of the right ventricle. Three cases of children who underwent cardiac catheterization while suffering from cor pulmonale due to adenotonsillar hypertrophy are reported. Right ventricular pressure averaged 44/5, PAO2 72, pH 7.32, and PACO2 52. All were clinically improved following adenotonsillectomy. Cardiac catheterization was repeated in one case, with right ventricular pressure dropping from 44/5 to 21/2, pulmonary vascular resistance from eight units to three, and PACO2 from 62 to 44.

Adenoidectomy↗