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Biomedical subjects

M Nitzan

Publications and source records attributed to M Nitzan.

At least 163 records · Page 9Linked to original sources
PubMed1979

Homocysteic acid: an examination of its possible growth hormone-like activity.

Hypophysectomized rats were injected intraperitoneally for 4 days with various doses of homocysteic acid or growth hormone. The effects of these compounds on epiphyseal cartilage thickness and circulating somatomedin activity levels were evaluated in an attempt to repeat the results of Clopath, Smith, and McCully, who reported that this compound had growth hormone-like activity. DNA polymerase activity in livers of animals treated with growth hormone or with 10 mg/day of homocysteic acid was also measured. Using larger number of animals and including higher doses of homocysteic acid than those previously employed, we did not observe an increase of epiphyseal cartilage thickness in homocysteic acid treated hypophysectomized rats. Growth hormone significantly increased cartilage thickness. DNA polymerase levels in homocysteic acid treated hypophysectomized rats were not substantially increased although a larger, dose-dependent increase was observed with pGH and hGH. Neither homocysteic acid nor GH increased circulating somatomedin activity under the conditions used in this investigation. These observations demonstrate that homocysteic acid was not a substance with growth hormone-like activity in our hands and cast doubt on its possible future usefullness as a substitute for GH in clinical situations.

Animals↗
PubMed1979

Placental transfer of analogs of glucose and amino acids in experimental intrauterine growth retardation.

We have employed the model in which one uterine artery is ligated to study maternofetal transport and tissue uptake of glucose and amino acids in the intrauterine growth-retarded rat. On the 18th day of gestation, the artery supplying one uterine horn was ligated. Two days later the rats received [3H]2-deoxyglucose and [14C]alpha-aminoisobutyric acid iv. One hour later the growth-retarded and control fetuses were delivered by Cesarean section and appropriate blood samples were obtained. The growth-retarded fetuses had an average weight reduction of 27%, significantly increased placental to fetal weight ratio and brain to body ratio, and a significantly reduced liver to body body ratio. Total radioactivity derived from tritiated deoxyglucose in whole fetal tissues, placenta, liver, and brain were significantly decreased in the intrauterine growth-retarded (IUGR) fetuses; this was also true per gram of tissue except for liver. Liver to plasma, brain to plasma, and whole fetal tissue to plasma 3H ratios were significantly increased in the IUGR group. The radioactivity derived from [14C]alpha-aminoisobutyric acid was significantly reduced in whole fetal tissues, placenta, liver, and brain in the IUGR fetuses whether expressed per whole organ or per gram of tissue. Significant differences in liver to plasma, brain to plasma, and whole tissue to plasma 14C ratios were not observed.

Aminoisobutyric Acids↗
PubMed1979

Infantile methemoglobinemia caused by food additives.

A small outbreak of toxic methemoglobinemia occurred among infants in a pediatric ward. Investigation revealed that the most likely source of toxicity was an approved fat preservative which had been added to a soybean infant formula by the manufacturer. This fat preservative contained three phenolic compounds having highly effective antioxygenic properties (butylated hydroxyanisole, butylated hydroxytoluene and propyl gallate). The outbreak ceased when the offending agents were eliminated from the food preparation. It is emphasized that the approval of chemicals for use in the food industry through toxicity studies does not necessarily guarantee against the hazards of toxicity, especially during infancy.

Disease Outbreaks↗
PubMed1978

Unusual bone involvement in congenital syphilis mimicking the battered child syndrome.

Congenital syphilis is re-emerging in modern society. The pediatric radiologist may contribute to its early diagnosis. A case of unusual bone involvement with fracture of the olecranon and facial bone lesions is described; the condition had to be differentiated from the "battered child syndrome". The problem of congenital syphilis as an infectious disease versus bone dystrophy is also discussed.

Battered Child Syndrome↗
PubMed1976

Effects of pregnancy on the development of acute uremic syndrome in the rat.

We evaluated the contributory role which gestational metabolic adaptions may play in the development of acute uremic syndrome in rats by studying the effects of nephrectomy in pregnant and nonpregnant animals. Whereas no significant differences in creatinine and uric acid concentrations were found between control and pregnant rats, urea concentrations were significantly lower in the pregnant animals before, as well as well as 6, 12 and 24 h after, bilateral nephrectomy. It is suggested that creatinine production, which is related to muscle mass, is not altered during late gestation, whereas urea synthesis, which is affected by catabolic and anabolic factors, is significantly reduced.

Acute Disease↗
PubMed1976

Cricopharyngeal achalasia associated with congenital suprabulbar paresis.

A case of congenital suprabulbar paresis is reported. The associated severe dysphagia which presented soon after birth was shown by radiographic and cineradiographic studies to be due to cricopharyngeal achalasia. During four years of follow-up a clear tendency to spontaneous improvement was seen. It is therefore suggested that the condition may have a favorable outcome without resorting to surgical intervention.

Bulbar Palsy, Progressive↗