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Biomedical subjects

F Lifshitz

Publications and source records attributed to F Lifshitz.

At least 73 records · Page 4Linked to original sources
PubMed1988

Radiologic anthropometry of the hand in patients with familial short stature.

Fifth metacarpal bone shortening (brachymetacarpia V) was recently described to be highly prevalent in children with familial short stature (FSS). To characterize the hand bones of FSS patients with and without brachymetacarpia V, the left hand bone age radiographs of 26 FSS children were reviewed. In 16/19 patients with clinical brachymetacarpia V radiographs revealed fifth metacarpal bone shortening with a gap of 2 mm or more between the distal end of the fifth metacarpal bone and a tangential line connecting the distal ends of the third and fourth metacarpal bones. Only one of 7 patients without clinical brachymetacarpia V had a gap of 2 mm. Radiologic anthropometry revealed that FSS patients with clinically shortened fifth metacarpal bone frequently had shortened first metacarpal bones, second and third proximal phalanges, and fifth distal phalanx as well. FSS patients without clinical fifth metacarpal bone shortening had shortened third and fourth metacarpal bones, fifth proximal phalanx, and fifth distal phalanx. Fifth metacarpal bone shortening was only detected clinically if the fourth metacarpal bone was not short as well. Reduction in height correlated more with reduction in metacarpal bone length than with that of the other hand bones. These peculiar tubular bone alterations commonly seen in FSS suggest a disturbance in endochondral ossification, the process primarily involved in tubular bone elongation.

Adolescent↗
PubMed1988

A survey to determine the prevalence of abnormal growth patterns in adolescents from a suburban school district.

A longitudinal survey of 1017 (514 male, 503 female) school health records was undertaken to assess the prevalence of normal and abnormal growth patterns in adolescents attending a suburban upper middle class junior-senior high school. The vast majority (97.4% of the students) were growing and gaining weight at a steady rate, maintaining a similar percentile for height and weight throughout adolescence. However, 75% of these students had mild deficits or excesses of body weight for height, which also remained constant throughout adolescence. Approximately 10% of the students had a body weight deficit or excess for height greater than 20%. These students were growing along normal percentile patterns. This was true whether the student had short, normal, or tall stature. Only a minority (2.6%) had an abnormal growth pattern. There were 18 students who had deteriorating linear growth and had decelerated across one or two major percentile lines for height. Only eight students demonstrated accelerated growth characterized by progressive weight gain greater than 10 kg/year and crossing a major percentile line for weight.

Adolescent↗
PubMed1988

Oral hydration solutions in experimental osmotic diarrhea: enhancement by alanine and other amino acids and oligopeptides.

Improvement of sodium absorption during the administration of oral hydration solutions (OHS) could increase the efficacy of formulations used in the treatment of infantile diarrhea. To test this hypothesis, selected protein breakdown products were evaluated as absorption enhancers in OHS of different osmolalities and Na-to-glucose ratios in an animal model of osmotic diarrhea induced by cathartics. A very significant increase in water and Na absorption occurred in rats with diarrhea when they were perfused with a 90-mmol/L-Na, 111-mmol/L-glucose OHS containing 30 mmol/L of L-alanine (Ala). The same effect on Na retention was observed with a protein hydrolysate (PrH) in rats with diarrhea. Glycine was not effective. Other experimental OHS were ineffective in rats with diarrhea. The data indicate that in this animal model of chronic diarrhea Na transport enhancers, such as Ala and a PrH, are most efficacious in the presence of higher Na concentration.

Absorption↗
PubMed1988

Neonatal thyroid disease: differential expression in three successive offspring.

Neonatal thyroid disease, manifested as either hyperthyroidism or hypothyroidism, has been described in the offspring of women with autoimmune thyroid disorders. We report clinical and laboratory observations in a mother with autoimmune thyroiditis who gave birth to three children with different forms of thyroid dysfunction. The first child was clinically normal, the second child had transient neonatal hyperthyroidism, and the third child had neonatal hypothyroidism. After the birth of the second child, the mother was found to be biochemically hypothyroid. Long-acting thyroid stimulator and antithyroid microsomal antibodies were detected in her serum. She was treated with L-T4 (0.15 mg/day). After the birth of her third child, the mother was found to have thyroid-stimulating immunoglobulins and TSH-blocking inhibitory immunoglobulins in her serum. The latter also were detected in the third newborn. Six weeks later, TSH-blocking inhibitory immunoglobulins were not detected in the child, but they persisted in the mother. This report further expands the spectrum of neonatal thyroid disease and suggests that differing disease syndromes in the newborn can occur depending on whether stimulating or blocking antibodies predominate in the mother.

Adult↗
PubMed1987

Pituitary function assessment in short stature by a combined hormonal-stimulation test.

We utilized a combined, hormonal-stimulation test (CHST) using sequentially-administered insulin, thyrotropin-releasing hormone, gonadotropin-releasing hormone, and levodopa to assess 51 children with short stature and/or pathologic growth. Growth hormone, thyrotropin, gonadotropins, cortisol, and prolactin levels were sampled over two hours. All patients with appropriate predicted adult heights, delayed bone ages, and normal growth velocities of 4.0 cm/y or greater demonstrated normal pituitary responses. Two of 12 patients with predicted heights 2.5 SDs lower than target height and normal growth velocity demonstrated isolated growth hormone deficiency. Nine of 11 patients had a pathologic growth hormone deficiency or panhypopituitarism. Evaluation of pituitary function by combined sequential hormonal stimulation is fruitful in children with pathologic growth patterns but not in children with normal growth velocities and normal predicted adult height.

Adolescent↗
PubMed1987

Quantitative alterations in the structural development of jejunal absorptive epithelial cells and their subcellular organelles in protein-energy-malnourished rats: a stereologic analysis.

The effect of protein-energy malnutrition (PEM) on the structural development of rat jejunal absorptive epithelial cells was evaluated. Stereologic characteristics of jejunal histologic subcompartments, epithelial cell surfaces and volumes, and volumes of key subcellular organelles (nuclei, mitochondria, Golgi apparatus, lysosomes) in crypt and villus mid and tip cells were determined by morphometric analysis of light and electron micrographs in well-nourished rats and rats with PEM. In rats with PEM there were developmental alterations in cells migrating on villi that were not seen in crypt cells. The amplification of the apical microvillus surface between mid and tip levels in well-nourished rats (679-1085 micron2/cell) failed to occur in rats with PEM (807-729 micron2/cell). This resulted in an estimated 60% reduction of total jejunal absorptive surface, from 10,070 cm2 in well-nourished rats to 3975 cm2 in rats with PEM. In contrast, the development of the basolateral surface, which requires much less membrane accrual, was unaffected by PEM. Villus mid and tip cells of rats with PEM also had increased cell volume and mitochondrial volumes. Microvillus surface area per cell appears dependent on the number of microvilli per cell, which equals the cell flat surface times the microvillus numerical density (number of microvilli per square micrometer) in well-nourished rats. However, this relationship was not demonstrable in rats with PEM.

Animals↗
PubMed1987

Pituitary-hypothalamic response in adolescents with growth failure due to fear of obesity.

Nine patients (4F, 5M) aged 12-17 years with "fear of obesity" were studied with a sequential stimulation test utilizing insulin, LRH, TRH, and L-dopa. The comparative groups were nine female with classic anorexia nervosa, five males with undifferentiated nutritional dwarfing, and nine children (1F, 8M) with constitutional growth delay. The serum TSH, glucose, cortisol, somatotropin, prolactin, LH, and FSH were sampled periodically over 2 hours. Basal T3, T4, transferrin, and Somatomedin-C levels were also obtained. The "fear of obesity" patients did not have any pituitary function changes that were unique. These patients, as well as the comparison groups, revealed a delayed TSH response in proportion to the weight deficit which, when expressed as an integrated response, correlated well to the weight deficit for height (P less than 0.001) and to the ability to recover from hypoglycemia (p less than 0.001). The Somatomedin-C level was low and correlated to the T3 level (p less than 0.05) and not correlated to the elevated Somatotropin levels. The pituitary response to combined stimulation in patients with fear of obesity was determined to be a component of the spectrum starting at normal and proceeding to the extreme undernutrition of anorexia nervosa. Pituitary responsiveness, therefore, changes not as a function of the etiology of the malnutrition, but simply as a function of its severity.

Adolescent↗
PubMed1987

Glycemic response in children with insulin-dependent diabetes mellitus after high- or low-glycemic-index breakfast.

To examine the effects of various carbohydrate foods on postprandial glycemia in diabetic children, we fed a mixed, isocaloric diet containing either high- or low-glycemic-index (GI) breakfast foods to 22 children with poorly controlled insulin-dependent diabetes mellitus (IDDM) and measured blood sugar response with and without adjustment of insulin doses. We found that IDDM children fed a high-GI meal showed a significantly higher serum glucose level than those fed a low-GI meal. However, such differences were not seen when the preprandial dose of regular insulin was adjusted to the amount of carbohydrate in feedings. Thus, as long as proper adjustment of insulin is made, the type of carbohydrate in a single mixed meal does not appear to have a significant effect on the postprandial glycemic response in children with long-standing poorly controlled IDDM.

Adolescent↗
PubMed1987

Parental health beliefs as a cause of nonorganic failure to thrive.

Parental misconceptions and health beliefs concerning what constitutes a normal diet for infants is reported as a cause for failure to thrive. There were seven patients (four boys, three girls), 7 to 22 months of age, who were evaluated for poor weight gain and linear growth. They were only consuming 60% to 94% of the recommended caloric intake for age and sex. The children's caloric intake had been restricted by their parents. They were concerned that the children would become obese, develop atherosclerosis, become junk food dependent, and/or develop eating habits that the parents believed were unhealthy. The parents instituted diets consistent with health beliefs currently in vogue and recommended by the medical community for adults who are at risk for cardiovascular disease. These diets caused the infants to experience inadequate weight gain and have a decreased linear growth rate. With nutritional counseling, all food restrictions were removed, the caloric intake was increased to 94% to 147% of the recommended intake for age. The weight gain rate increased significantly (P less than .05) from 0.1 +/- 0.1 kg/mo to 0.4 +/- 0.3 kg/mo, and the linear growth rate increased significantly (P less than .05) from 0.4 +/- 0.4 cm/mo to 1.0 +/- 0.6 cm/mo within 3 months of therapy. Exaggerated concerns about excessive food intake in childhood and/or concern about the sequelae of eating an improper diet has resulted in this entity of failure to thrive due to parental health beliefs.

Attitude to Health↗
PubMed1986

Premarin priming does not alter growth hormone release following exercise.

We evaluated the usefulness of premarin priming on exercise induced growth hormone release and the value of combining several growth hormone screening agents in a large population of prepubertal children. Two hundred five short healthy prepubertal children growing below the 5th percentile in height were studied. One hundred forty-four were screened with exercise following glucose ingestion, while 61 were primed with estrogen prior to glucose and exercise testing. Premarin priming did not significantly increase the number of our patients who responded to exercise nor to glucose; 86% and 88.5% of non-primed and primed patients, respectively, responded with a growth hormone increase greater than or equal to 8 ng/ml following exercise and glucose. Glucose loading alone was not associated with a high enough growth hormone rise to rule out growth hormone deficiency in most of our children. Age (less than or equal to 5 yr) was associated with lower post-exercise growth hormone levels and a higher failure rate to testing in both primed and non primed children. Premarin priming does not seem to alter the growth hormone releasing capacity to exercise of prepubertal children. The combined use of exercise, glucose loading and premarin priming in a single screening test does not improve on the results obtained by growth hormone exercise screening alone.

Adolescent↗
PubMed1986

Magnesium status in children with insulin-dependent diabetes mellitus.

We assessed the magnesium status in 67 children with insulin-dependent diabetes mellitus (IDDM) in various degrees of diabetic control and its changes during the evolution of the disease. This was done by measuring fasting serum magnesium and 24-hr urinary magnesium clearances when patients were first studied, as well as subsequently on follow-up. In 23 of these patients the retention of intramuscular magnesium was also assessed in relation to the degree of diabetic control and the duration of the illness. The mean +/- SD serum magnesium levels were significantly lower in diabetic children as compared to nondiabetic controls (1.91 +/- 0.22 vs 2.12 +/- 0.26 mg/dl, p less than 0.001). Serum magnesium in diabetic children correlated with glycosylated hemoglobins (r = -0.358, p less than 0.001), but not with 24-hr glycosuria (r = -0.296). On follow-up of patients, serum magnesium significantly increased when IDDM control improved and decreased when the control worsened. Diabetic patients had increased urinary magnesium clearances compared to nondiabetic subjects (5.26 +/- 3.58 vs 3.60 +/- 1.36 cc/min, p less than 0.05). All but five of the 23 patients given the magnesium load retained more than 40% of the dose, with a mean +/- SD retention of 58.7 +/- 5.1%. There was no correlation between the amount of retained magnesium and the duration of the illness, degree of diabetic control, amount of glycosuria, magnesuria, magnesemia, glycosylated hemoglobins, or serum lipids. The data confirm that lower than control serum magnesium levels occur frequently among children with poorly controlled IDDM. Moreover, there might be magnesium deficiency in IDDM, as indicated by the high retention of magnesium when given intramuscularly. The deficiency of this ion may or may not be accompanied by decreased serum magnesium levels and may result from increased urinary magnesium losses in children with IDDM.

Adolescent↗
PubMed1986

Breast feeding and insulin-dependent diabetes mellitus in children.

We have evaluated the hypothesis of a protective effect of human milk on the development of insulin dependent diabetes mellitus (IDDM). We studied the feeding histories of 95 diabetic children and compared them with controls consisting of their non-diabetic siblings and a pair matched group of nondiabetic peers of the same age, sex, geographical location, and social background. The incidence of breast feeding in diabetic children was 18%. This was similar to the control group. The duration of breast feedings was also similar among all three groups. There was no difference in the age of introduction of solid food between diabetic and nondiabetic children. Twice as many diabetic children, however, received soy containing formula in infancy as compared to control children. The mean age of onset of IDDM was not related to the type of feeding during infancy. The incidence of positive thyroid antibodies was two and one half times higher in formula-fed diabetic children than in breast-fed ones. In our studies we were unable to document any relationship between the history of breast feeding and subsequent development of IDDM in children.

Adolescent↗
PubMed1986

Alterations in jejunal transport and (Na+-K+)-ATPase in an experimental model of hypoxia in rats.

Hypoxia was induced by exposing rats to an atmosphere of 93% N2, 7% O2 for 4-48 hr. The animals became hypoxic as indicated by a decreased blood PaO2 (mean +/- SEM: 48 +/- 10 mm Hg). Hypoxia was accompanied by metabolic acidosis (pH 7.22 +/- 0.02) and decreased serum bicarbonate levels (9.0 +/- 4.0 meq/liter). Hypoxic rats also showed evidence of tissue hypoxia; liver tryptophan oxygenase levels were increased to 21 +/- 2 nmole/min/mg protein. In the hypoxic animals there was decreased jejunal mucosal (Na+-K+)-ATPase activity and an inhibition of active intestinal transport of sodium, glucose, 3-O-methylglucose, galactose, tyrosine, phenylalanine, and glycine as determined by in vivo perfusion studies. Jejunal fructose transport, which has a large passive component, was unaffected by hypoxia. The electrolyte, carbohydrate, and amino acid transport alterations produced by hypoxia were seen in the absence of an effect on jejunal cell number, DNA synthesis, or cell turnover. There was also no evidence of histological or ultrastructural damage. Furthermore, studies with a luminal macromolecular tracer, horseradish peroxidase, indicated that the jejunal lumen-to-blood barrier to macromolecules was also unaltered in these hypoxic animals. In vitro local oxygenation of the jejunum, by bubbling of 95% O2:5% CO2, markedly improved sodium and glucose (but not 3-O-methylglucose) absorption in hypoxic rats and control rats. The (Na+-K+)-ATPase activity of the jejunal mucosa of hypoxic rats was significantly enhanced by the local bubbling of 95% O2:5% CO2. Overall, our data indicate that during relatively mild conditions of hypoxia there is an inhibition of jejunal (Na+-K+)-ATPase activity and related transport processes that is prevented by in situ oxygenation.

Amino Acids↗
PubMed1985

Low-dose oral clonidine. A simple and reliable growth hormone screening test for children.

We evaluated the efficacy and side effects of a low dose of oral clonidine hydrochloride on growth hormone release in 24 healthy short children; ten received 100 micrograms (group A) and 14 received 50 micrograms (group B). The mean +/- SD growth hormone peak at 60 minutes was 14.5 +/- 6.3 mg/mL in group A v 11.6 +/- 6.1 mg/mL in group B. Failure rate (growth hormone less than 10 mg/mL) was 10% in group A and 36% in group B. The drop in cortisol levels was similar in both groups. Blood pressure did not change significantly, and only mild somnolence was noted in all. A single dose of oral clonidine hydrochloride approximating 100 micrograms/sq m, followed by one blood sample after 60 minutes seems to be an effective and safe screening test for growth hormone deficiency in short children.

Adolescent↗