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Biomedical subjects

J Baker

Publications and source records attributed to J Baker.

At least 325 records · Page 18Linked to original sources

Survival of animal tissue cells in primary culture in the absence of serum.

The ability of cells from tissues of several species of animals to survive in primary culture without serum was tested. Of the species tested, cells from the kidneys of Macaca mulatta (rhesus) and Cercopithecus aethiops (vervet) monkeys and chicken embryo cells not only survived under these conditions, but indeed developed into confluent monolayer cultures. The addition of either serum or its globulin or albumin fraction enhanced the development of cell monolayers and permitted those cells unable to survive in the absence of serum to do so. Certain specific protein trypsin-inhibitors not of serum origin were unable to provide conditions necessary for cell survival or growth when used in place of serum proteins.

Animals↗

The permeability of the small intestinal mucosa: a study using iron.

Various substances containing iron were injected into the lumen of the small intestine in rabbits and into the mesenteric arterial supply. Sections of the mucosa were stained for ferric ions by immersing for 30 minutes into equal parts of 2% HCl and 2% potassium ferrocyanide (Prussian Blue reaction). The ferric ion is bound to various cell structures and its passage through the mucosa could therefore be demonstrated. Iron appeared to pass from the blood into epithelial cells, especially near the tips of the villi, and also between cells as far as the junctional membrane. Studies using (59)Fe demonstrated the rapidity of transfer of iron from the blood into the intestinal lumen. After a period of ischaemia epithelial cells in other situations also appeared permeable to iron. The implications of the loss of substances from the blood into the lumen by these routes is discussed.

Animals↗

Small intestinal permeability in animals and man.

The permeability of the human small intestine has been studied by measuring the clearance from the plasma into the intestinal lumen of substances with molecular weights ranging from 60 to 80 000. A direct relationship has been demonstrated between intestinal loss and plasma concentration and an inverse one between clearance and molecular size.The permeability of the rabbit small intestine has been studied at various levels by measuring the blood-to-lumen clearance of substances of different molecular size ranging from 60 to 40 000. It has been demonstrated that there is a progressive fall in permeability from the duodenum to the terminal ileum for all the substances studied.

Animals↗

Nigel John.

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Delivery, Obstetric↗

Bordetella pertussis serotypes in the United States.

To determine the Bordetella pertussis serotypes currently causing whooping cough in the United States, recently isolated cultures from different geographic areas were studied. Specific adsorbed antisera were prepared in our laboratory and used in both tube and slide agglutination tests. Among the 177 cultures isolated during 1966 and 1967 in seven states and one Canadian province, the predominant serotype was 1.3 (or 1.3.6), represented by 85% of the cultures. Fifteen cultures were serotype 1.2.3.4.6. The 376 cultures isolated in the Grand Rapids area during the last 30 years showed a changing pattern from serotype 1.2.3 during the early years to the currently prevailing 1.3 (or 1.3.6). During the 2-year study period, seven cultures of B. parapertussis were isolated in Michigan, and seven were received from other states. One culture of B. bronchiseptica, recovered from a child in Boston, was sent to us.

Agglutination Tests↗