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Biomedical subjects

D Baum

Publications and source records attributed to D Baum.

At least 37 records · Page 2Linked to original sources

Chicken growth hormone: cDNA-synthesis and base sequence.

1. Growth hormone (GH)-cDNA was synthesized from poly A(+)-mRNA extracts of chicken pituitary glands. 2. Chicken-cDNA library was cloned into E. coli. 3. Base sequence analysis of chicken GH-cDNA revealed only 70% similarity compared with duck GH-cDNA, and 97% similarity with a previously published chicken GH-cDNA sequence. 4. Dissimilarities in base sequences are primarily observed in the 3'-non-coding region of GH-cDNAs (chicken and duck). 5. Comparisons of amino acid sequences of chicken and duck GH exhibit only three substitutions, while the amino acid sequences of GHs of chicken are identical.

Amino Acid Sequence↗

Adrenal cortical adenoma in the spinal canal of an 8-year-old girl.

An ectopic adrenal cortical adenoma containing high levels of androstenedione but without clinically detectable virilizing effects was found in the spinal intradural space of an 8-year-old girl. The tumor, which was located at the L2 level, manifested itself clinically by a short history of bilateral leg pain. It was well encapsulated; therefore, total surgical removal was accomplished. The light microscopic appearance of the tumor was typical of adenomatous adrenal cortical tissue. Ultrastructurally, it also showed characteristic features of steroid-producing tumors, including very abundant smooth endoplasmic reticulum and giant mitochondria with tubulovesicular and circular cristae. Frozen tissue analyzed by radioimmunoassay was found to contain almost 20 times the normal tissue level of androstenedione. There was no elevation of cortisol or aldosterone levels in the tumor. Postoperative magnetic resonance imaging (MRI) scan of the retroperitoneum showed no abnormalities in the patient's adrenal glands. Serum androstenedione levels were normal. We postulate that the adenoma developed from congenital ectopic rests of intraspinal adrenal tissue. Although ectopic occurrence of adrenal cortical tissue has been recorded in other areas, neither such rests nor tumors developing from them have been previously reported within the spinal canal.

Adenoma↗

Pediatric heart transplantation.

Heart transplantation has been performed successfully in the pediatric age group for just over 10 years, yet early results are encouraging, and this procedure has moved from the realm of experimental therapy to that of accepted medical practice for certain specific conditions. In infants and children with cardiomyopathies or with congenital heart disease for which no reasonable standard surgical alternative exists, heart transplantation offers the best hope for long-term survival. Most important, in those patients surviving heart transplantation, rehabilitation has been almost universally complete. Although the long-term prospects for pediatric heart transplant patients are still unknown, we have now accumulated sufficient experience in adults suggesting the potential for decades-long survival. Future improvements in diagnosis and treatment of rejection and prevention of the complications of immunosuppressive therapy will continue to improve the prospects for lifelong survival in these patients.

Adolescent↗

Adipose tissue thymidine kinase activity in man.

Thymidine kinase activity was studied during human adipose tissue development. Adipose tissue was obtained from the groin in 81 persons, aged 7 wk through 60 yr. None had a metabolic or growth disorder. Adipose tissue thymidine kinase activity was highest in infants and lowest in adults. Peak thymidine kinase activity was seen in the early postnatal period and a lesser elevation was found in the preadolescent years, coinciding with hypothesized periods of proliferation of preadipocytes in man. In contrast, during adulthood, a time of stable lipid-laden cell number, thymidine kinase activity was lower. Although these adipose tissue samples include both stromal and fat cells, the data support the hypothesis that adipose tissue growth in early infancy is primarily the result of cellular proliferation, and that little cellular proliferation occurs after infancy, except possibly for a brief period prior to adolescence.

Adipose Tissue↗

Medication compliance in children with asthma.

The aim of the study was to determine whether self-management skills, when taught to asthmatic children and their parents, would improve medication compliance. The latter was assessed by a variety of procedures including serum theophylline levels, pill counts by parents, and self-monitoring measures. Results indicated a group receiving self-management training showed no greater gains in medication compliance, self-concept, or health locus of control than did a self-monitoring-only group. However, children in the former group became more responsible for initiating appropriate treatment for their attacks than did youngsters in the latter group.

Adolescent↗

Pentobarbital effects on plasma catecholamines: temperature, heart rate, and blood pressure.

The effects of intravenous pentobarbital were studied in dogs. Plasma pentobarbital concentrations were inversely related to epinephrine and norepinephrine concentrations. Plasma catecholamines appeared fully suppressed at pentobarbital levels greater than 25-30 micrograms/ml. Furthermore, pentobarbital levels were negatively related to rectal temperature, heart rate, and mean blood pressure. The methods of pentobarbital administration influenced plasma pentobarbital as well as epinephrine and norepinephrine levels, temperature, heart rate, and blood pressure. These observations suggest the possibility that pentobarbital inhibits the sympathetic nervous system, which in turn may affect temperature, heart rate, and blood pressure. Because pentobarbital anesthesia affects plasma catecholamine concentrations, the regimen used in animal models requires consideration when interpreting data potentially influenced by the sympathetic nervous system.

Animals↗

Pentobarbital anesthesia suppresses basal and 2-deoxy-D-glucose-stimulated plasma catecholamines.

Since pentobarbital anesthesia is known to attenuate certain autonomic reflexes, we tested whether pentobarbital would suppress both basal and stimulated levels of plasma catecholamines and whether a large stimulus might counterbalance this suspected suppression. In untrained dogs, sampled by venipuncture, pentobarbital (30 mg/kg iv) decreased the plasma concentration of epinephrine (E) from 146 +/- 9 to 38 +/- 8 (SE) pg/ml (n = 46) and norepinephrine (NE) from 276 +/- 13 to 91 +/- 10 pg/ml (both P less than 0.0005), suggesting that barbiturate anesthesia suppresses sympathetic outflow in these mildly stressed animals. Pentobarbital also had a marked suppressive effect on the lower baseline catecholamines (E, 84 +/- 14 pg/ml; NE, 118 +/- 10 pg/ml; n = 6) of trained, chronically catheterized dogs, suggesting that it was capable of suppressing resting sympathetic outflow as well. To determine whether pentobarbital anesthesia also suppressed reflex activation of the sympathetic nervous system, the plasma catecholamine response to the neuroglucopenic agent, 2-deoxy-D-glucose (2-DG), was measured in conscious and in pentobarbital-anesthetized dogs. In conscious dogs, the administration of 2-DG (100 mg/kg iv) doubled the base-line plasma concentration of E and NE 30 min after the 2-DG injection. In contrast, the administration of 2-DG (100 mg/kg iv) to pentobarbital-anesthetized dogs produced no significant increase of either plasma catecholamine, suggesting marked suppression of this sympathetic reflex.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗

Growth and tissue abnormalities in young people with cyanotic congenital heart disease receiving systemic-pulmonary artery shunts.

The effects of systemic-pulmonary artery shunts on growth, body composition, and adipose tissue were studied in 29 children, aged 2 to 16 years, with cyanotic congenital heart disease. Of these, 16 received surgical shunts and 13 were unoperated. Postoperatively, all patients who received shunts were better oxygenated (systemic oxygen saturation 69 +/- 11% preoperatively and 84 +/- 4% postoperatively; mean +/- standard error of the mean) and were symptomatically improved. However, the groups were not significantly different in height, weight, lean body mass, total body fat, lean/fat ratio, cellular lipid content, or total number of lipid-containing fat cells. Age at operation did not seem to influence the effects of surgery. These observations suggest that growth and certain measurements of tissue development were unaffected by surgical systemic-pulmonary artery shunts despite increased oxygenation and symptomatic improvement after operation.

Adipose Tissue↗

Antibody dependent cytotoxicity of human colostrum phagocytes.

Monocytes and polymorphonuclear neutrophils of human colostrum were identified using cytochemical staining procedures. The ability of colostral phagocytes to function in antibody dependent cellular cytotoxicity was found to be satisfactory at high effector/target cells ratio (20:1) Colostral monocytes showed a diminished cytotoxicity when compared to monocytes of adult or neonatal peripheral blood at low effector/target cells ratio (1:1). This could be due to the extensive fat ingestion by these cells or other inhibitory factors found in colostrum.

Antibody-Dependent Cell Cytotoxicity↗

Results of intraventricular baffle procedure for ventricular septal defect and double outlet right ventricle or d-transposition of the great arteries.

Thirty patients with ventricular septal defect and d-transposition of the great arteries or double outlet right ventricle underwent placement of an intraventricular baffle to achieve physiologic correction. Eighteen of these patients also required an external conduit to establish continuity between the right ventricle and the pulmonary artery. There was an overall 22 percent early mortality rate, although the rate was 63 percent in patients who weighed less than 10 kg. There was an additional 20 percent late mortality rate, primarily related to conduction disturbances and pulmonary vascular obstructive disease, problems that have not occurred in patients operated on since 1974. Of the survivors, all are asymptomatic and as a group have achieved a significant weight gain. Many have residual hemodynamic abnormalities that required cardiac catheterization for precise assessment. Four patients have been reoperated on, with no additional mortality.

Adolescent↗

Norepinephrine-stimulated lipolysis in acute and chronic hypoxemia.

The effects of acute and chronic hypoxemia on norepinephrine-stimulated lipolysis were studied in dogs. Right-to-left shunts were created in experimental dogs to render them chronically hypoxemic (PaO2 37-55 torr). Control animals received sham operations (PaO2 greater than 70 torr). During air ventilation, there was no significant difference in norepinephrine-induced glycerol and free fatty acid (FFA) rises in the control and experimental groups. In control dogs, glycerol and FFA responses to norepinephrine were unaffected by acutely lowering oxygen tensions (PaO2 46-48 torr) to levels found in air-breathing experimental dogs. However, greater acute reductions in oxygen tensions (PaO2 less than 30 torr) in both control and experimental animals resulted in pronounced glycerol and FFA falls from the elevated levels produced by norepinephrine infusions during air ventilation. PaO2 levels less than 30 torr similarly decreased the glycerol and FFA elevations in control animals given phenoxybenzamine and norepinephrine. As with severe hypoxemia, propranolol suppressed glycerol and FFA increases stimulated by norepinephrine. Theophylline did not influence the hypoxemic-induced glycerol and FFA falls. These observations suggest that severity was important in the hypoxemic inhibition of norepinephrine-stimulated lipolysis; the effects of low oxygen breathing were not ameliorated by chronic hypoxemia. A beta-adrenergic receptor abnormality appears to contribute to this inhibition.

Acute Disease↗

Stress hyperglycemia and the adrenergic regulation of pancreatic hormones in hypoxia.

Stress hyperglycemia occurs in normal and chronically hypoxemic dogs when PaO2's are acutely lowered below 30 torr. Several factors are thought to contribute to the rise in blood glucose. The initial fall in PaO2 activates the sympathetic nervous system, stimulating alpha and beta adrenergic receptors. Because of reduced beta receptor function, alpha receptor effects predominate, promoting glucagon and inhibiting insulin release. The changes in pancreatic hormones in conjunction with the direct effects of hypoxemia and alpha receptor stimulation increase hepatic glycogenolysis. Meanwhile, glucose clearance is decreased because of elevated circulating levels of catecholamines and low insulin concentrations. This combination of events plays a major role in the development of hyperglycemia. Since high blood glucose levels seems to protect the brain and other vital organs at low oxygen tensions, the development of hyperglycemia may represent an important protective mechanism in severely hypoxemic animals, including humans.

Animals↗

Early heart failure as a cause of growth and tissue disorders in children with congenital heart disease.

Height, weight, total body fat, lean body mass, size of fat cells and total number of lipid-containing fat cells were compared in two groups of children, ages 2-6 years, with congenital heart disease. Twelve children who developed heart failure in infancy made up one group and 14 asymptomatic patients made up the other. No patient was cyanotic or had undergone surgical repair. Patients with heart failure were shorter and lighter than asymptomatic patients. Whereas both fat and lean tissues were less in the heart failure group, reduction in body fat was more important in producing underweight. Although there was no difference in the size of fat cells, the number of lipid-laden fat cells was diminished in the children who had early heart failure. Thus hypocellularity of fat cells appeared to be the major determinant of diminished body fat with heart failure. Because shortness and decreased lean tissue were associated with these adipose tissue abnormalities, it is likely that widespread changes are caused by early heart failure. As previously reported with hypoxemia, the early development of heart failure seems to produce tissue changes that handicap growth.

Adipose Tissue↗