Accidental hypothermia in an alcoholic population

Thirty-nine cases of accidental hypothermia are reviewed. Data indicate that mortality varies with the presence of underlying disease rather than with the degree of hypothermia or the methods of rewarming. In 31 patients with hypothermia alone (average temperature 85 °F) mortality was 6.25 per cent. In eight patients with hypothermia and another primary condition (average temperature 84 °F) mortality was 75 per cent.Intractable cardiac arrhythmia has been reported as the primary cause of death in hypothermia. In these patients, death during hypothermia resulted from pulmonary complications. Ventricular arrhythmias, when they occurred, were responsive to routine measures such as electrical cardioversion and myocardial suppressant drugs. Methods of treatment are discussed.     

Hemodynamic,electrocardiographic, and metabolic effects of fructose diphosphate on acute myocardial ischemia

The hemodynamic, electrocardiographic, and metabolic responses of dogs with acute myocardial ischemia to intravenous administration of fructose-1,6-diphosphate (FDP) were assessed.Analysis of the results (compared to dextrose control) revealed evidence of major improvement of LVEDP and cardiac output, significant decrease of the ST segment, and large increases of ATP and CP in the ischemic district and to a lesser degree in the normally perfused myocardium. These results indicate that FDP intervenes in the Embden-Meyerhof pathway not only as a high energy substrate but also as a metabolic regulator influencing the activity of phosphofructokinase and that of pyruvate kinase. FDP also stimulates glycolysis in dog erythrocytes and increases their ATP and 2–3 DPG content by a factor of 2.The most significant finding in these studies is that this biochemical intervention appears to restore the depressed activity of glycolysis in ischemic myocardium.     

The etiology of enamel hypoplasia: a unifying concept

In a study of children with chronic disorders of calcium and phosphate homeostasis, enamel hypoplasia was found in hereditary vitamin D-dependency rickets and in hypoparathyroidism, conditions characterized by hypocalcemia, and was not found in X-linked hypophosphatemic rickets, a condition in which the plasma calcium concentration is normal. The occurrence of enamel hypoplasia bore no relation to the plasma phosphate concentration. Enamel hypoplasia has also been reported in other pediatric disorders in which hypocalcemia is a major sign (for example, vitamin D deficiency, prematurity, and neonatal tetany). The existence of enamel hypoplasia in a hypoparathyroid or rachitic patient, when correlated with the chronology of enamel mineralization, helps to establish the time of onset of hypocalcemia. The observations led us to the hypothesis that a low serum calcium concentration during enamel formation is a specific determinant of enamel hypoplasia. This hypothesis may be relevant to the etiology of linear enamel hypoplasia, an endemic lesion of primary teeth in children of many Third World countries that predisposes the teeth to dental caries. The hypothesis may therefore be relevant also in explaining the prevalence of caries in the primary teeth of children in many underdeveloped countries.     

Giant cell tumor of the lunate bone: A case report

A case of giant cell tumor occurring in the lunate bone is presented. The rarity of this location is discussed.     

Fetal fuels. I. Utilization of ketones by isolated tissues at various stages of maturation and maternal nutrition during late gestation.

The availability and utilization of B-hydroxybutyrate as an alternate oxidative fuel during fasting hypoglycemia has been examined in the rat conceptus at 18 and 20 days gestation. A 48-hr maternal fast between days 16 and 18 or 18 and 20 resulted in a 50% fall in fetal glucose levels and a marked rise in B-hydroxybutyrate, i.e., 30-fold at 18 and 60-fold at 20 days. Tissue concentrations of B-hydroxybutyrate or acetoacetate did not exceed extracellular levels. Placenta, fetal brain, carcass, and liver all oxidized 14C-labeled B-hydroxybutyrate to 14CO2 when incubated in vitro in the presence of B-hydroxybutyrate. Highest rates of oxidation were apparent in the placenta, followed by brain, liver, and carcass. The D isomer of B-hydroxybutyrate appeared to be oxidized preferentially by all tissues studied. Despite levels of 3-ketoacid CoA transferase and acetoacetyl CoA thiolase lower at 18 than at 20 days, rates of oxidation in individual tissues incubated under identical concentrations of substrate were similar at both times. In liver and brain, increasing rates of 14CO2 generation proportionate to graded concentrations of B-hydroxybutyrate in vitro indicated that such rates were probably determined by substrate availability. B-hydroxybutyrate oxidation in extrahepatic fetal tissues was unaffected by maternal fasting. By contrast, fetal liver derived from fasted mothers generated significantly less 14CO2 from B-hydroxybutyrate than livers from fed mothers. It has been suggested that capabilities for ketone utilization are widespread in tissues of the conceptus, and that such utilization may fulfill in part the oxidative demands for continued anabolic growth during fasting hypoglycemia in the mother.     

Assessment of cognitive function in the elderly

Neuropsychological testing of the five basic areas of mental function (attention, language, memory, visuospatial ability, and conceptualization) can be used to help differentiate the effects of normal aging, delirium, depression, and dementing disorders, and in developing appropriate treatment or management plans. The author assesses the meaning of the test results with particular reference to Alzheimer's disease.