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Biomedical subjects

K M Rasmussen

Publications and source records attributed to K M Rasmussen.

60 records · Page 4Linked to original sources

Effect of folic acid supplementation on pregnancy in the squirrel monkey (Saimiri sciureus).

Supplementation of squirrel monkeys with folic acid improved hematologic and folate status, maternal weight gain during pregnancy, and infant birth weight. Thus the folate content in the stock diet (1.4 microgram/g) did not meet the requirement for pregnancy. Low plasma vitamin B12 values suggest that vitamin B12 in the stock diet (22 ng/g) also was not adequate. Changes with folic acid supplementation are similar to those for human subjects, indicating that the squirrel monkey is an appropriate model for folic acid deficiency in pregnancy in man.

Animals↗

Vital statistics from a laboratory breeding colony of squirrel monkeys (Saimiri sciureus).

An analysis of 512 pregnancies that occurred over a 9-year period in a laboratory colony of squirrel monkeys (Saimiri sciureus) revealed yeat-to-year variation in pregnancy outcome and birth weight. Although births occurred through the year, 72% were between May and August. Male infants outnumbered females 1.31:1 and were heavier at birth. Birth weight was an important determinant of infant survival. Maternal age did not affect birth weight in this sample. Dams present in the colony for long periods tended to deliver smaller infants with a decreased potential for survival. Reproductive causes contributed to 48% of the maternal deaths. Homorrhage at or near the time of delivery was the principle cause of maternal reproductive mortality. Most neonatal deaths were attributable to accident, prematurity or trauma.

Abortion, Veterinary↗

Folacin deficiency and requirement in the squirrel monkey (Saimiri sciuresus).

Acute folacin deficiency was studied in eight young squirrel monkeys (Saimiri sciureus). Half of the animals were fed a semipurified deficient diet (no added folic acid) and half were fed a control diet (0.84 mg of added folic acid per kilogram of dry diet). Monkeys fed the deficient diet lost weight and suffered from diarrhea and dehydration leading to the death of one of the animals after 6 weeks. Folacin deficiency also was studied in six older animals fed diets containing varying levels of added folic acid. Monkeys fed diets containing 0.14 or 0.27 mg of added folic acid per kilogram of dry diet slowly developed alopecia, a scaly dermatitis, and a mild macrocytic anemia. When these animals were fed the deficient diet, they lost weight rapidly, the alopecia and dermatitis worsened, excretion of formiminoglutamic acid in the urine increased, and a severe megaloblastic anemia with profound intramedullary hemolysis developed. Deficient monkeys had low plasma and red blood cell folacin values but maintained normal plasma vitamin B12 values. Repletion of the animals fed the deficient diet with injections of folic acid reversed both the hematological and physical deterioration. The folacin requirement for maintenance of body weight in these animals was 28 micrograms of total folacin per kilogram of body weight per day. More than 75 micrograms of total folacin per kilogram of body weight/day may be needed to assure growth and normal hematological parameters and bone marrow cytology.

Animals↗

Megaloblastic erythropoiesis and tissue depletion of folic acid in the cat.

Dietary requirement for folic acid was shown in the cat. Folic acid deficiency was produced by feeding young cats a deficient diet (0.125 mg of total folate/kg of dry weight by analysis) for 22 weeks. The folic acid-deficient cats grew normally, but had reduced plasma, red blood cell, and liver folate concentrations in comparison with those concentrations in cats fed a control diet (1.36 mg of total folate/kg).. Urinary excretion of formiminoglutamic acid was increased in all deficient diet cats 24 hours after L-histidine injection. Erythroblasts in bone marrow smears from folic acid-deficient cats were megaloblastic; they showed abnormal nuclear chromatin patterns and had nuclear-cytoplasmic asynchronism.

Animals↗