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Biomedical subjects

W van Pelt

Publications and source records attributed to W van Pelt.

42 records · Page 3Linked to original sources
PubMed1988

Growth of lung and thorax dimensions during the pubertal growth spurt.

In the follow-up study of adolescents residual volume (RV), vital capacity (VC), closing volume (CV), thorax height and thorax width were measured at six month intervals over a six year period; 149 girls and 477 boys, whose ages ranged between 11.5 and 18.5 yr during the follow-up, were investigated. In healthy subjects and in those with respiratory symptoms the rates of change of thoracic dimensions, as calculated by a robust linear regression technique, were moderately well correlated; the growth rates of RV and VC were only slightly correlated, and both were moderately well correlated with changes in thorax dimensions. Thorax height increased relative to thorax width in boys and girls during the follow-up. In boys, thorax height continued to grow, when standing height and thorax width had attained adult values in girls. Thus the thorax attains a more elongated shape. During the adolescent growth spurt the residual volume as a percentage of total lung capacity (RV%TLC) within subjects increased on average 0.6% per yr, and closing volume as a percentage of vital capacity (CV%VC) decreased on average 0.5% per yr. Both of these changes can be accounted for by decreased thorax compliance and increased outward chest recoil at low lung volumes.

Adolescent↗
PubMed1986

Time course of arterial repair following endothelial denudation in the rat carotid artery. A morphometric study in Wistar and Sprague-Dawley rats.

Repair processes in the intima and media of the rat carotid artery were studied morphometrically for time intervals of up to 28 days after injury induced by air-drying. Air-drying injury included endothelial denudation as well as medial necrosis. Repair was most rapid between days 9 and 11 after injury as regards the increase in myointimal lesion size, the extent of repopulation of the media and re-endothelialization. After day 11, myointimal lesion size continued to increase until day 28. Medial repair, however, almost completely ceased at day 11, 25% of the inner media and 5% of the outer media remaining necrotic. At day 21, the vessels were almost completely re-endothelialized; however, even at day 28, about 10% of the middle of the vessel was still permeable to Evans Blue. The response of Sprague Dawley rats to injury differed from that of Wistar rats. Compared with Wistar rats, Sprague Dawley rats showed larger myointimal lesions, less medial necrosis and slower endothelial repair. It is suggested that the extent of medial necrosis and the speed of endothelial regeneration affect the arteriosclerotic response in rats.

Animals↗
PubMed1979

The influence of the lower beak on the interorbital septum-prenasal process complex in the chick embryo.

The effect of removal of the lower beak on the development of the interorbital septumprenasal process (ISPP) complex was studied in chick embryos. In normal development the angle between the ventral contour of the interorbital septum and the long axis of the prenasal process increases. At the same time the angle between the ventral contour of the interorbital septum and the basal plate increases. After surgical removal of the prospective lower beak at stage 29, the position of the entire ISPP complex was altered in stage-38 embryos and the prenasal process showed elongation. In stage-38 embryos in which the prospective upper beak had been removed at stage 29, Meckel's cartilage was elongated. It is concluded that straightening of the angle between the ventral contour of the interorbital septum and the long axis of the prenasal process is not influenced by the lower beak, whereas the position of the entire ISPP complex and the size of the prenasal process are under the epigenetic influence of the lower beak. The position and size of Meckel's cartilage are under the epigenetic influence of the upper beak.

Animals↗
PubMed1978

Screening and prevention of nutritional anemia during infancy. A prospective study of food fortification.

No important differences in hemoglobin and hematocrit values occurred among subgroups of a cohort of 295 healthy, mature infants who were fed various dietry regimens of iron-fortified products, including cereal, whole milk, and corn syrup. Among all infants between the ages of 4 and 27 months, the incidence of hematocrit readings and hemoglobin levels below 30% and 10 g/dl, respectively, was 0.6%, and below 33% and 11 g/dl, respectively, was 3.2%. Because of the low incidence of nutritional anemia after age 4 months, initial screening should be done at 1 to 4 months of age, and selectively thereafter. A formula of evaporated milk and corn syrum plus iron-fortified cereal during early months, then whole milk and a more diversified diet including continued use of iron-fortified cereal during later months of infancy, provides a nutritionally sound and economical diet with sufficient iron.

Anemia↗
PubMedDate not supplied

Morphometry of air-drying-induced arteriosclerosis in rat carotid artery. Effect of air-flow rate.

Arteriosclerosis in the Wistar rat carotid artery was induced by air drying of the endothelium, a procedure that caused media necrosis. We describe a number of technical modifications that facilitate the procedure and minimize damage to the vessel wall (i.e., media necrosis). A morphometric study of vessel wall changes induced by endothelial denudation at various air-flow rates showed that necrosis of the inner medial layer and lesion size and position were constant at all flow rates used (greater than or equal to 28 ml/min). The extent of necrosis of the outer medial layers, the endothelial repair, and the shape of the lesions varied with the air-flow rate used. Since at an air-flow rate of 28 ml/min medial necrosis was minimal and myointimal lesion development was as extensive as at higher flow rates, we consider this air-flow rate to be optimal for this model of experimental arteriosclerosis. We hypothesize that the shape of the myointimal lesion is determined by the timespan of endothelial denudation and by the availability of smooth muscle cells in necrotic and normal media. Furthermore, the proliferation of the smooth muscle cells and their migration into the intima is probably dominant over the repopulation of the media by these cells.

Air Movements↗