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Biomedical subjects

M Cornblath

Publications and source records attributed to M Cornblath.

At least 37 records · Page 2Linked to original sources
PubMed1981

Increased 125I-insulin receptor binding to erythrocytes of hypoglycemic infants and children.

The measurement of 125I-insulin specific binding to erythrocytes obtained from seven infants and children with various hypoglycemic syndromes showed a significant increase in six patients with recurrent, documented, symptomatic hypoglycemia (percent specific 125I-insulin binding 9 to 14 versus 6.1 +/- 1.4% mean +/- 2 S.D. for 13 controls). The increase was due to an increased number of receptors sites per cell rather than to increased affinity for insulin. The patients included three children with nesidioblastosis, all after 90% pancreatectomy, two with leucine sensitivity, and two with glycogen storage disease type I. One of the patients with leucine sensitivity, who for 2 years before the study had no hypoglycemia, had normal insulin values (less than 10 microunits/ml). Thus, a symptomatic hypoglycemia correlated better with increased 125I-insulin binding than with plasma insulin values. Furthermore, Diazoxide therapy in two patients caused a mild but consistent decrease in the number of insulin receptor sites, and the institution of continuous nocturnal nasogastric feedings in a patient with glycogen storage disease type I was followed by amelioration of the hypoglycemia and a marked increase in 125I-insulin specific binding from 5.2 to 9.5%.

Adolescent↗
PubMed1978

Effect of L-alanine infusion on gluconeogenesis and ketogenesis in the rat in vivo.

1. In 48 h-starved 6-week-old rats the 14C incorporation in vivo into blood glucose from a constant-specific-radioactivity pool of circulating [14c]actateconfirmed that lactate is the preferred gluconeogenic substrate. 2. Increasing the blood [alanine] to that occurrring in the fed state increased 14C incorporation into blood glucose 2.3-fold from [14c]alanine and 1.7-fold from [14c]lactate. 3. When the blood [alanine] was increased to that in the fed state, the 14C incorporation into liver glycogen from circulating [14c]alanine or [14c]lactate increased 13.5- and 1.7-fold respectively. 4. The incorporation of 14C into blood acetoacetate and 3-hydroxybutyrate from a constant-specific-radioactivity pool of circulating [14c]oleate was virtually abolished by increasing the blood [alanine] to that existing in the fed state. However, the [acetoacetate] remained unchanged, whereas [3-hydroxybutyrate] decreased, although less rapidly than did its radiochemical concentration. 5. It is concluded that during starvation in 6-week-old rats, the blood [alanine] appears to influence ketogenesis for circulating unesterfied fatty acids and inversely affects gluconeogenesis from either lactate or alanine. A different pattern of gluconeogenesis may exist for alanine and lactate as evidenced by comparative 14C incorporation into liver glycogen and blood glucose.

Acetoacetates↗
PubMed1978

Reciprocal regulation of glucose and glutamine utilization by cultured human diploid fibroblasts.

Human diploid fibroblasts utilize both glucose and glutamine as energy sources. The utilization of glutamine by fibroblasts is regulated by glucose, and vice versa. This conclusion is supported by the following observations: (1) essentially identical growth rates were observed in Eagle's minimum essential medium (MEM)3 in which the glucose concentration was either 5.5 mM or was maintained between 25 and 40 micrometer, (2) the total glutamine utilization by fibroblasts increase at least 30% in medium with 25 micrometer to 70 micrometer glucose compared to medium with 5.5 mM glucose, while the rate of glutamine-1 or 5-14C oxidation to CO2 increased 5-fold as the glucose concentration was decreased to zero, (3) 2 mM glutamine inhibited glucose-6-14C oxidation by 88% and stimulated glucose-1-14C by 77% in log phase cells and (4) glutamine oxidation in normal medium contributed approximately 30% of the energy requirement of human diploid fibroblasts.

Cell Division↗
PubMed1977

Hypoketonaemic effect of L-alamine. Specific decrease in blood concentrations of 3-hydroxybutyrate in the rat.

1. The injection of L-alanine (50-100 mg/kg) into 35-day-old rats that had been starveed for 48 h increased blood L-alanine concentration to values observed in fed animals and lowered the blood concentration of 3-hydroxybutyrate within 2 min. 2. This hypoketon aemic action of L-alanine was specific for 3-hydroxybutyrate, since the acetoacetate concentrations did not change significantly. 3. The decrease in 3-hydroxybutyrate elicited by L-alanine was not related to changes in the blood concentrations of insulin, glucagon, growth hormone, glucose, unesterified fatty acids, lactate or pyruvate. 4. The injection of L-alanine resulted in a decrease in total ketones that was apparently unrelated to their increased peripheral utilization. These results are interpreted as an anti-ketogenic action of L-alanine. 5. The data suggest that L-alamine lowers ketone-body formation in starved rats, possibly via an alteration in hepatic redox equilibrium.

Acetates↗
PubMed1977

Effects of starvation and development on mitochondrial acetoacetyl-coenzyme A thiolase of rat liver.

The activity of the putative ketogenic beta-oxoacyl-CoA thiolase from mitochondria of rat liver increases with starvation, during neonatal life, and after the injection of glucagon. These changes are associated with alteration in ketonaemia. The changes in activities of this species of thiolase are not associated with significant alterations in the apparent affinity (Km) for the ketogenic substrate, acetyl-CoA. These results support a role for thiolase in the regulation of ketogenesis.

Acetyl-CoA C-Acetyltransferase↗
PubMed1976

Transient hepatomegaly and hypoglycemia. A consequence of malicious insulin administration.

On two occasions, a 3 1/2-year-old black girl had severe hypoglycemia associated with transient hepatomegaly. The plasma insulin level during the second hypoglycemic episode was excessive and led to a diagnosis of malicious insulin administration. We suggest that plasma be obtained for insulin determination in children with hypoglycemia, and that transient hepatomegaly may be a helpful sign in cases of insulin overdose.

Child Abuse↗
PubMed1976

Growth of human diploid fibroblasts in the absence of glucose utilization.

Normal human diploid fibroblasts were able to undergo one to two cell divisions without glucose utilization in Eagle's minimum essential medium plus 10% dialyzed fetal calf serum if the medium was supplemented with hypoxanthine, thymidine, and uridine (supplemented medium termed HTU-MEM). Under these conditions, the added purine and pyrimidines were required for nucleic acid synthesis, as shown by the inability of Lesch-Nyhan fibroblasts to grow in HTU-MEM. Normal human diploid fibroblasts continued to produce lactate in HTU-MEM, but at a greatly reduced rate. Since cells grew in HTU-MEM without glucose utilization, the probable energy and carbon source was glutamine, which is present in relatively high concentration. Furthermore, the rate of glutamine utilization per cell division was 2-fold greater in HTU-MEM than in medium with 5.5 mM glucose. These results suggest that glutamine can be a major energy source for cells grown in vitro.

Cell Division↗
PubMed1976

Ability of exogenous alanine to lower blood beta-hydroxybutyrate during development in rats.

The intraperitoneal injection of L-alanine into 10- and 21-day-old fed Wistar rats resulted in blood alanine levels of 3-5 mM and in a rapid, significant decrease in the concentration of beta-hydroxybutyrate (betaOHB) in blood. The drop in betaOHB was unrelated to changes in the concentrations of pyruvate, lactate, or glucose. The intraperitoneal injection of glutamate at the same age had no effect on betaOHB values. In 2-day-old pups and in older weaned animals, the injection of alanine had either no effect or increased the levels of betaOHB in blood. The most rapid disappearance of exogenous alanine occurred in 35-day-old and not in 10- and 21-day-old rats. These data suggest that alanine has a depressant effect on the level of circulating betaOHB at a specific stage in the animal's maturation.

Alanine↗
PubMed1976

Neonatal pancreatic beta-cell hyperplasia: report of a case with failure of diazoxide and benefit of early subtotal pancreatectomy.

A newborn infant with pancreatic beta-cell hyperplasia had persistent hypoglycemia due to hyperinsulinism. After medical management, including the use of diazoxide and constant glucose infusions had proved ineffective, a subtotal pancreatectomy was curative. Cumulative experience seems to indicate that there should be little delay in performing a subtotal pancreatectomy when aggressive medical management cannot maintain normoglycemia in a neonate.

Diazoxide↗
PubMed1976

GM3 gangliosidosis: a novel human sphingolipodystrophy.

A male infant of nonconsanguinous Jewish parents had clinical features of pseudo-Hurler's syndrome. A maternal uncle with similar features had previously died at 21/2 months of age. Following death at 3 1/2 months of age, analysis of the patient's brain and liver revealed increased amounts of ganglioside GM3, a virtual absence of higher ganglioside homologues (GM3, GM1, GD1a, and GT1) and a deficiency of the biosynthetic enzyme, UDP-Gal NAc:GM3 N-acetylgalactosaminyl-transferase. Since the biochemical findings denote a novel state of ganglioside deficiency, clinical findings emphasizing points of distinction from other causes of pseudo-Hurler's syndrome are presented.

Brain↗
PubMed1976

Neonatal hypoglycemia revisited, 1975.

Between 1971 and 1973, the frequency of neonatal hypoglycemia was 4.4/1,000 total inborn live births or 15.5/1,000 low-birthweight infants. During that same time, of 257 transferred infants, 13 or 5.1% were hypoglycemic. The hypoglycemic manifestations differed between the inborn and outborn infants as well as from those previously described for transient symptomatic hypoglycemia. This required a new classification for low blood glucose values in the neonate, based on intrauterine nutrition, stress, symptoms, and underlying pathology. Four categories were defined: category I: early transitional hypoglycemia; category II: secondary hypoglycemia; category III: classical transient hypoglycemia; and category IV: recurrent, severe hypoglycemia. One outborn infant was in the latter group due to beta-cell hyperplasia and was only cured after a 90% pancreatectomy. Data revealed that early treatment of perinatal asphyxia was associated with a decreased frequency of hypoglycemia. While not a prospective survey, the evidence suggested that current neonatal intensive care may decrease the frequency of transient symptomatic neonatal hypoglycemia.

Apgar Score↗
PubMed1975

Deficient Ganglioside Biosynthesis: a novel human sphingolipidosis.

An unusual lipid storage disese is chracterized by the accumulation of hematoside (Gms3) in the patient's liver and brain. In contrast to the other sphingoliidoses, the accumulation of Gm3 is not the result of a defective catabolic reaction, but is the first disorder caused by deficiency in ganglioside biosynthesis to be described in man.

Brain↗
PubMed1975

The school health team and school health physician: new role and operation.

A new concept of school health redefines the school physician's role as dealing primarily with behavior and learning disorders in children. It is an on-site operation, using a multidisciplinary team of professionals. We outlined internal team operations, as well as modes of remediation. Many types of behavior and learning problems were seen by our school health team during the first year of operation. It is important to recognize the multiplicity of diagnoses on individual elementary school children, as well as the differentiation of early organics from late functional primary causes. We need to reassess the delivery of school health care. The expansion of school health to include the multidisciplinary team approach to behavior and learning problem is a primary priority. We suggest using outside medical agencies for periodic physical illness.

Adolescent↗
PubMed1975

Glycerol intolerance in a child with intermittent hypoglycemia.

A 3-yr-old boy was investigated for numerous episodes of fatigue, irritability, pallor, and sweating, which began at 11 mo of age, when he had an episode of symptomatic hypoglycemia with ketonuria. He had euphoria, mental confusion, drowsiness, nausea, and vomiting 1-5 hr after oral administration of glycerol in doses of 0.5-1.0gm/kg. Orally administered MCT (1 gm/kg) had similar effects. On one occasion, oral glycerol also provoked hypoglycemia, as had a 16 1/2 hr fast. Intravenously administered glycerol (0.09 gm/kg) induced an immediate loss of consciousness from which he recovered spontaneously after 30 min; there were no changes in blood glucose values. Intravenously administered fructose (0.25 gm/kg) was tolerated normally. Leukocytes showed normal activities for FDPase, glycerol kinase, and glycerol phosphate dehydrogenase. The restriction of dietary intake of fat has been associated with a marked improvement in physical and mental activities. These observations suggest a unique, yet undifined intolerance to glycerol, which suggest caution in the diagnostic use of glycerol in the investigation of hypoglycemia as well as in the therapy of increased intracranial or intraocular pressure.

Alanine↗
PubMed1975

Cerebral sponginess and GM3 gangliosidosis; ultrastructure and probable pathogenesis.

Extensive multifocal vacuolation of the cerebral hemispheres, brain stem, cerebellum, optic nerves and spinal cord were demonstrated in a 3 1/2 month-old infant. This co-existed with marked increases in cerebral and hepatic ganglioside GM3 (hematoside), absence of its higher homologues (GM1 and GM2) and absence of tissue N-acetylgalactosaminyl transferase. Ultrastructurally, there are major abnormalities in myelin and astroglia. The absence of identifiable "storage" material is believed to correlate with an enzymatic defect involved in ganglioside anabolism. A familial occurrence of this disorder is strongly suggested by the clinical history.

Astrocytes↗