Biomedical subjects

S J Baker

Publications and source records attributed to S J Baker.

At least 109 records · Page 6Linked to original sources

PubMed1975

Vitamin B12 absorption--a study of intraluminal events in control subjects and patients with tropical sprue.

The intraluminal fate of orally administered radioactive vitamin B12 has been studied in control subjects with normal vitamin B12 absorption and those with vitamin B12 malabsorption due to tropical sprue. In control subjects 1 to 21% of the dose was bound to sedimentable material and 37 to 75% was bound to immunoreactive intrinsic factor. In subjects with vitamin B12 malabsorption due to tropical sprue, the results were identical with the control subjects. Bacteriological studies showed a statistically significant correlation between both the number of flora in the jejunum and the number of bacteroides in both the jejunum and ileum and vitamin B12 malabsorption. In patients with tropical sprue who have normal intrinsic factor secretion, the vitamin B12 absorptive defect is not due to binding of the vitamin to bacteria or to alteration to the intrinsic factor vitamin B12 complex in the intestinal lumen. The lesion appears to be one of the mucosal cell receptors or of the cells themselves, possibly caused by bacterial toxins.

Bacteroides↗

PubMed1975

Identification of radioactive 17beta-estradiol-17-beta-D-glucuronide and 17alpha-estradiol-17-beta-D-glucuronide in the urine of the domestic fowl after intramuscular injection of [4-14C]estrone.

Two previously uncharacterized radioactive estrogen conjugates, 17beta-estradiol-17-beta-D-glucuronide (3-hydroxyestra-1,3,5(10)-trien-17beta-D-glucopyranosiduronate) and 17alpha-estradiol-17beta-D-glucuronide (3-hydroxyestra-1,3,5(10)-trien-17alpha-yl-beta-D-glucopyranosiduronate), have been identified in small but significant amounts in avian urine and in a ratio of approximately 2:1 after intramuscular injection of [4-14C]estrone.

Animals↗

PubMed1975

W.H.O. sponsored collaborative studies on nutritional anaemia in India. 1. The effects of supplemental oral iron administration to pregnant women.

A W.H.O. sponsored collaborative study of the effects of iron supplementation to pregnant women was carried out in Delhi (northern India) and Vellore (southern India). Supplementation was given under supervision from the 26th to the 36th or 38th week of pregnancy. A control group received only placebo; one group received vitamin B12 and folic acid alone; four groups received vitamin B12, folate and a daily iron supplement ranging from 30 to 240 mg of elemental iron as ferrous fumerate, and one further group received 120 mg of iron without B12 or folate. Groups receiving no iron showed a fall in mean stet concentration. Those receiving iron showed a rise in haemoglobin, the best results being in the groups receiving 120 and 240 mg of iron together with vitamin B12 and folate. Even in these groups however there was still a high prevalence of anaemia and iron deficiency at the end of the trial period. Iron alone did not produce as good results as iron plus vitamin B12 and folate. The supplementation had no detectable effect on the birth weight of the children, nor on the haemoglobin concentration of the infants at three months of age. The daily absorption of iron in the pregnant women, as judged from the increase in haemoglobin mass, was not as satisfactory as expected. Possible reasons for this are discussed. It is concluded that to provide these women with adequate iron a daily oral supplementation of 120 mg of elemental iron or more is needed. This can only be achieved by medicinal means. Before supplementation can be recommended on a public health scale, further information regarding the cost and expected benefits of such measures must be obtained.

Administration, Oral↗

PubMed1975

An electron-microscopic study of jejunal mucosal morphology in control subjects and in patients with tropical sprue in southern India.

The ultrastructure of the jejunal mucosa obtained by peroral biopsy from 7 control subjects and 12 patients with tropical sprue was studied. Compared with biopsies from control subjects in temperature zones, southern Indian control subjects showed minimal increase in lysosomes in surface epithelial cells, an occasional dark-staining degenerating epithelial cell in the upper two-thirds of villi, and an increase in cellular infiltration of surface epithelium and lamina propria. The jejunal epithelial cells of tropical sprue patients had abnormal microvilli, marked increase in lysosomes, increase in intracellular fat, and degenerative changes in rough endoplasmic reticulum and mitochondria. Two types of degenerating epithelial cells, designated pale and dark based on their staining quality, were seen in the villi. Pale staining degenerating cells were also seen in the crypts. The basement membrane region showed an amorphous deposit with many collagen fibers and fat droplets. The epithelial layer and lamina propria showed increased cellular infiltration. In one biopsy from a patient with sprue, particles of possible viral origin were seen.

Adolescent↗

PubMed1975