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Biomedical subjects

G Zajicek

Publications and source records attributed to G Zajicek.

At least 163 records · Page 9Linked to original sources

Iron mobilization in the pregnant rat.

Iron exchange in the pregnant rat was quantitated by repeated determinations of plasma iron turnover (PIT), transferrin iron distribution and measurements of storage iron and food iron utilization employing selective radio-iron probes. Despite a sixfold increase in PIT, intestinal absorption of iron accounted for 40% of the PIT throughout pregnancy, with variations not exceeding +/- 5%. Increased fetal requirements were efficiently compensated for by the mobilization of iron from maternal tissue stores and by increased absorption, and there was no subsequent reduction in iron supply to maternal tissues. Enhancement of iron absorption occurred in the absence of a reduction in serum iron levels or the size of iron stores. In view of the close correlation between PIT and rates of absorption it is postulated that iron absorption in the pregnant rat is regulated by PIT which in turn is determined by the rate of plasma iron clearance by the placenta and the maternal erythroid marrow.

Animals↗

The rodent incisor tooth proliferon.

The rodent incisor tooth is the site of five cell populations proliferating in harmony: amelocytes, odontocytes, pulp cells, endothelial cells and the periodontal ligament. Their proliferating regions are located in the apex tip, where the various cells originate. Cells displaced from the tooth origin at the apex toward the periphery, mature to perform their specified function. The proliferative events in the tooth are summarized in a conceptual model of the incisor proliferon. The proliferon is an oriented structure with an origin and periphery. It consists of four basic elements: parenchyma, connective tissue, blood vessels and nerve fibres, all interacting continuously. All four are indispensable in the definition of the proliferon.

Ameloblasts↗

Inner enamel epithelium cell production rates.

Crowning of all four rat incisors slows down their eruption rate, leading to a diminution of cell production by the inner enamel epithelium (IEE). The production rate by 100 progenitor cells is dominated as production rate %. The normal IEE in rats weighing 200 g produces daily 67 cells %. In the crowned incisor this rate drops to 15 cells % while during accelerated eruption rate and IEE cell production rate remains unchanged and an eruption of 6-4 mum reflects a production of 1 cell % by the IEE. A method which relates labelled cell displacement along the IEE with its cell production rate is described and its applicability to other cell renewal systems discussed.

Animals↗