Biomedical subjects
Publications and source records attributed to S Haberman.
An umbilical cord cyst was detected in a fetus who underwent ultrasonography at 38 weeks' gestation for clinical suspicion of intrauterine growth retardation. Such an association should alert the clinician to the possibility of aneuploidy, thus guiding clinical management. This case represents the second report of a cystic umbilical lesion in a fetus with trisomy 18.
Several experiments have shown that non-aphasic, right hemisphere-damaged adults encounter difficulty solving syllogistic reasoning problems. In order to confirm and further explore the nature of this deficit with different linguistic material, patients with focal cerebral insult were asked to detect logical errors in sentences describing familiar causal situations. The findings revealed significant impairments in detecting errors after insult to anterior portions of the right hemisphere and to the left hemisphere, but qualitatively different patterns of errors in these two groups of patients. We conclude that the right hemisphere may make a unique contribution to sentence processing.
In view of the studies demonstrating the involvement of eicosanoids (prostaglandins and hydroxyperoxides, including leukotrienes) in ovulation in several mammalian species, we have examined the activity of the two enzyme systems, lipoxygenase and cyclooxygenase in human granulosa cells obtained from women undergoing in-vitro fertilization--embryo transfer. The activity of cyclooxygenase was assessed by radioimmunoassay of prostaglandin E and of 6-keto-prostaglandin F1 alpha, the conversion product of prostacyclin, accumulated in the culture medium of granulosa cells. Lipoxygenase activity was detected by the conversion of [14C]arachidonic acid into its products (hydroxyperoxides and leukotrienes) separated by reversed phase high-performance liquid chromatography. The results confirmed the activity of cyclooxygenase in human granulosa cells, production in vitro of prostaglandin E and prostacyclin and demonstrated the presence of active lipoxygenase enzymes. These results support the possible involvement of eicosanoids in ovulation of the human.
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A statistical method is presented to assess and compare cardiac valve performances. Patient survival and valve performances have been separated, and valve function and malfunction have been described in comprehensive and comparable terms. Formulas are proposed to calculate the significance of the difference between two survival probabilities as well as to calculate the instantaneous rate of events and the median remaining lifetime.
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A feasibility study has been carried out to determine whether a population-based registry of neurological disease can be established using the Hospital (Inpatient) Activity Analysis (HAA) records for England and Wales. The study provides a valuable opportunity to use and test the HAA system. The neurological disease chosen was the Guillain-Barré-Strohl syndrome (GBS), because it would be expected that most patients would be admitted to hospital, and recurrent attacks or chronicity are rare. In this study it has been demonstrated that, for GBS, a neurological registry, based on HAA records, provided an excellent source of data to measure the incidence of the disease and potentially any change of incidence over time. The proportion of coding errors was found to be under 5%.
The frequency distribution of deaths from cerebrovascular disease in England and Wales in 1975 by month of occurrence is described. The distribution is compared with that for related diseases, in particular ischaemic heart disease, hypertensive disease, pneumonia and bronchitis. The principal feature in all these diseases is high mortality in winter and spring and low mortality in late summer, but the range of variation is wider for pneumonia and bronchitis. The seasonal distribution of cerebrovascular disease death is similar in both sexes, all ages at death and for deaths at home and deaths in a hospital or institution. For both sexes the proportion of cerebrovascular disease deaths occurring at home increases significantly with age at death. Four hypotheses are examined to explain this characteristic seasonal mortality pattern, which is related inversely to ambient temperature, and similar to the seasonal pattern of the incidence and prevalence of cerebrovascular disease.
Incidence rates for cerebrovascular disease reported by community-based and hospital-based studies during the past 15 years are analysed. The range of variation between area is wide, with Japan and Finland experiencing the highest age-adjusted rates. Of 16 studies reporting incidence rates by sex, 15 showed a male excess, and nine of these were significant when the incidence rate was age-adjusted. Overall, the excess is about 30% for both community-bases and hospital-based studies. For cerebral infarction the excess is about 45%. Intracerebral haemorrhage shows little difference between the two sexes and subarachnoid haemorrhage shows a male deficit of about 50%. These findings are self-consistent.
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The use of survival analysis in cardiac surgical reports has been widely accepted in order to characterise and compare performances of different valve prostheses. However, the analyses that have been described elsewhere may be improved in several respects. The original method proposed for prosthetic valve evalation examined follow-up related to patients rather than the valves themselves and therefore neglected the possibility of factors other than the valve itself which could affect the fate of cardiac patients. Furthermore, there has not yet been any application of life table methods to compare two different sets of data, or to estimate the average time before an event occurs. The present work defines valve function and malfunction and separates patient survival from valve performance. We define statistical indices, namely the median remaining lifetime and the instantaneous decrement rate. Both indices can be useful; the former measures the average survival time and the latter focuses attention on the intensity of risk changes. Using established statistical theory we calculate the significance level of difference between two independent survival rates. We qualify the presentation of probabilities with a statement of the associated standard errors.
A striking reduction in the levels of glucose 1,6-diphosphate and an increase in cyclic GMP were found in muscle from dystrophic mice. Concomitant to these changes, the allosteric activity of phosphofructokinase was found to be markedly reduced. These findings could offer an explanation for the observed reduction in glycolysis in the dystrophic muscle.
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Based on previous studies which have revealed that glucose 1,6-bisphosphate (Glc-1,6-P2) is a potent inhibitor of muscle hexokinase and an activator (deinhibitor) of phosphofructokinase and phosphoglucomutase, the effect of epinephrine on the levels of this regulator in rat diaphragm muscle was investigated. It was found that epinephrine caused an increase in diaphragm Glc-1,6-P2 levels, accompanied by a reduction in the activity of hexokinase and an activation (deinhibition) of phosphofructokinase and phosphoglucomutase. N6-2'-O-dibutyryl cyclic AMP was able to mimic all these effects of epinephrine. The concentration of glucose-6-phosphate was not changed by epinephrine, under conditions in which the hormone produced an increase in cyclic AMP and Glc-1,6-P2 levels and the concomitant decrease in hexokinase activity. It was also shown that Glc-1,6-P, in the concentration range found after epinephrine, inhibited the diaphragm hexokinase and deinhibited phosphoglucomutase. These results may suggest a mechanism of epinephrine action by which the activities of hexokinase, phosphoglucomutase and phosphofructokinase, through the action of Glc-1,6-P2, are synchronized with the cyclic AMP-mediated activation of glycogen phosphorylase, to achieve an increase in total glycogenolysis and glycolysis and a concomitant reduction in glucose utilization by the muscle.
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