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Biomedical subjects

H Friesen

Publications and source records attributed to H Friesen.

70 records · Page 4Linked to original sources

Growth hormone investigation in patients with mental dysfunction.

Seventy-three children with disorders of physical growth and mental development were stimulated by insulin hypoglycemia and arginine infusion and their human growth hormone (HGH) responses were determined. Only four patients exhibited absent or impaired pituitary hormone secretion and one of them presented a unique syndrome of panhypopituitarism associated with intrauterine growth retardation, long eyelashes and eyebrows, sparse hair and degeneration of the retina. Statistical analysis indicated no significant HGH peak concentrations in groups of either tall males or stunted females who possessed various sex chromosome abnormalities, nor did these groups differ in a variety of clinical parameters including age, physical growth, birth weight and intelligence.

Adolescent↗

A radioimmunoassay for human prolactin.

A radioimmunoassay for primate prolactin has been developed, with [(131)I] monkey prolactin, and antibodies to monkey or human prolactin. The assay is specific for prolactin; human growth hormone, and human and monkey placental lactogen show no significant crossreaction. The assay is sensitive enough to measure prolactin concentrations in the sera of most humans studied. The concentration of prolactin in the serum of normal children and adults of either sex was usually below 30 ng/ml, while very high concentrations (up to 500 ng/ml) were observed in newborn infants. The serum prolactin concentration during the menstrual cycle showed no definite increase in the luteal phase. Of 24 patients with galactorrhea, 20 had prolactin concentrations above 30 ng/ml; the highest value observed was 1500 ng/ml. In contrast, 12 of 13 patients with acromegaly had concentrations within the normal range. During pregnancy, the concentration of prolactin in serum rose progressively from an average of 30 ng/ml in the first trimester to 200 ng/ml at term. Postpartum, prolactin concentrations fell to normal levels after 1-2 weeks. Suckling was a potent stimulus to prolactin release, increasing its concentration in serum some 10- to 20-fold.

Acromegaly↗

Studies of the secretion of monkey placental lactogen.

A radioimmunoassay for monkey placental lactogen (MPL) was developed to study the factors controlling the secretion of MPL. The sensitivity of the assay was 1 ng MPL per ml. Human and monkey growth hormone, and human placental lactogen (HPL) showed minimal cross-reactions with MPL. Maternal MPL concentrations as measured in 40 rhesus monkeys increased progressively throughout pregnancy to a mean of 5000 ng/ml at term while umbilical vein MPL was less than 50 ng/ml. After term delivery maternal MPL concentrations decreased rapidly with a t(1/2) of 20 min.After fetectomy but with retention of the placenta, MPL concentrations decreased by 25% reaching a plateau over a 6 hr period. Experimental abruption of the secondary placenta within 1 hr produced a 50% decrease in MPL concentration. After ligation of the fetal vessels supplying the secondary placental disc, MPL increased transiently and then decreased to levels significantly below those of the control period. These studies suggest MPL secretion is not directly controlled by the fetus but is sensitive to changes in placental blood flow. The pregnant rhesus monkey serves as a useful model for investigating factors which may regulate HPL secretion because of the close similarity between MPL and HPL secretion.

Animals↗

Perinatal asphyxia at Port Moresby General Hospital: a study of incidence, risk factors and outcome.

We investigated the incidence and outcome of perinatal asphyxia (PA) at Port Moresby General Hospital by a retrospective chart review and prospective collection of data, spanning a total of 2.5 years. 125 babies weighing more than 2000 g at birth with a gestation of 34 weeks or more and with no obvious congenital abnormalities were diagnosed to have PA. During the same time period 22,700 liveborn babies were delivered, a PA incidence of 5.5/1000 livebirths. There was a 31% mortality and considerable morbidity. Hospital records for 114 affected babies and 115 controls (the next baby born by normal delivery) were compared. Significant risk factors for PA were: previous stillbirth or neonatal death, fetal heart rate abnormalities, membranes ruptured for more than 12 hours prior to delivery, meconium staining, antepartum haemorrhage, maternal fever, prolonged first and second stages of labour, preterm or post-term delivery and operative delivery. In only 73 affected babies was the 5-minute Apgar score recorded as 6 or less. All 34 of the babies with grade 3 hypoxic ischaemic encephalopathy (HIE) either died (30) or had serious neurological impairment. The treatment of affected babies remains largely supportive and some causes of PA are currently unavoidable. It is, however, widely accepted that some cases of perinatal asphyxia may be prevented by the delivery of high-risk pregnancies in obstetric facilities with appropriate intervention and by good neonatal resuscitation. Sophisticated or expensive equipment is not a necessity.

Apgar Score↗