Intestinal epithelium regeneration in rats receiving methotrexate and a trial of regulating this regeneration with pentagastrin and glucagon.

The study was carried out in three groups of rats: group I of 36 rats received methotrexate, group II of 36 rats were given methotrexate, pentagastrin and glucagon, group III of 12 rats served as control. For histological examination the ileum was taken from the animals killed on days 1, 2, 3, 4, 7 and 9 after the last injection of methotrexate. Besides histological examinations the mitotic index and the number of cells in crypt longitudinal-section were determined. Relatively low doses of methotrexate caused characteristic changes in the intestinal mucosa: disappearance of mitotic figures, shortening of crypts particularly on the first day after the last dose of methotrexate. On the following days regeneration processes were noted causing an excessive epithelial proliferation observed up to the 9th day after the last dose of methotrexate. This indicates that the mobilized mechanisms of epithelial proliferation stimulation exert their effect fairly long. In the group receiving methotrexate administration of pentagastrin and glucagon contributed to the increased number of mitoses in crypt epithelium and the number of cells on crypt longitudinal-section. These observations are an evidence of a beneficial effect of the hormones administered to the rats in the regeneration of the ileal epithelium damaged by the cytostatic agent.

Granulomatous lung disease in children by aspiration of medications.

Post mortem examinations of 8 infants, 11 d to 5 months old and one 12 year old girl, demonstrated foreign bodies in the lungs which could be identified as orally administered drugs: cholestyramine (Questran) and phenobarbital (Luminal, Gardenal) or phenydantin-components. The microscopic changes caused by such deposits and the histologic methods of identifying medicines are presented. The authors point to the role of aspiration in deposit formation and to the pseudomiliary granulomatous nature of subsequent changes. It is proposed to define the alterations as a separate form of aspiratory lesion in children.

Experimental desquamation of intestinal epithelium for in vivo studies of regeneration.

Complete removal of villous as well as upper-crypt epithelium was achieved in vivo by vibration of an intestinal segment using tetraphenylboron sodium (TPB) as a disassociation agent.

Histological studies on the regeneration of small-intestine epithelium of rats irradiated with sublethal doses of X rays.

The dynamics of regeneration of small-intestine epithelium was studied in rats irradiated with X-rays in sublethal doses of 550, 600 or 750 R. Sixty-two irradiated and 22 control animals were used in the experiment. They were killed 1,2,4,6,8,14 and 25 days after the irradiation. Specimens of duodenum and jejunum were examined histologically, the sections being stained with H.E. and p.a.S. Already 1 and 2 days after irradiation the intestinal villi became shorter and deformed. The blood vessels were damaged, the enterocytes showed features of degeneration and vocuolization, the epithelium was detached by the exudate which accumulated in the stroma. Irradiation markedly disturbed the regeneration of intestinal epithelium in the period from the 1st to the 6th day. Cytological calculations indicate that on the 1st and 2nd days after irradiation the number of epithelial cells of the villi, and particularly of young cryptal ones, markedly dropped. On the 4th and 6th days increased proliferation of young cryptal cells considerably surpassed the physiological rate. The accompanying disturbances in differentiation consisted in a decreased acidophilic to basophilic cells ratio and in retardation of maturation of goblet cells. The absolute number of goblet cells was increased, as well as their proportion to the number of enterocytes.