[Post-traumatic repair of the tibia in rats]. / Posttravmaticheskiaia reparatsiia bolshebertsovo kosti u krys.

Posttraumatic bone repair was studied histologically in 88 adult male Wistar rats. Thick, semithin and thin sections were stained with standard methods and investigated (microanatomy, histology, EM). The experimental animals were divided into five main groups: 1) control; 2) trained (swimming); 3) immobilized; 4) formalized (0.2 mg/kg i.m. every day); 5) alcoholised (3% alcohol instead of drinking water). The first group was divided into animals wit periost, contacted with endost and bone marrow and animals without periost contacts (with isolated periosteum). Bone perforation causes local hemorrhage and tissue destruction. Thr first reparative changes on the first-seventh days (proliferating fibroblasts and capillary sprouts grow into the blood clot and injured area, degranulation of neutrophils and tissue basophils, appearance of activated macrophages and osteoclasts) occur in soft tissue. Intensive collagen synthesis in fibroblasts began. On the fourteenth day collagen synthesis in osteoblasts was increased (packed collagen fibrils in vacuolated cytoplasm). Posttraumatic osteohistogenesis on d 4-21 was generally completed on d 28-42 bone formation (morphogenesis) and permanent remodeling were continued. Periosteal osteogenesis and bone repair require an existence of the periosteum contact with endosteum and bone marrow (growth and differentiation of endosteal bone callus was inhibited and those of periosteal callus was arrested in groups with isolated periosteum). Similar results were achieved in i.p. heterotopic autografts of repaired tissue in diffusion chamber (with isolated periosteal osteogenetic cells appearing only by 21st day after bone injury). In trained rats bone repair was stimulated, while in immobilised and in injured animals it was inhibited and resulted in chronic inflammation of bone marrow and abscesses.

[Reconstruction of the cervical esophagus using a revascularized ileal graft (experimental study)]. / Rekonstruktsiia sheinogo otdela pishchevoda revaskuliarizovannym ileotransplantatom (éksperimental'noe issledovanie).

The clinic and histomorphology of the revascularized ileum autograft used for the reconstruction and/or replacing the cervical oesophagus in 76 adult mongrel dogs were examined from the 1st to 372nd postoperative days. In 46% of the cases complete recovery of autografts has been established. In 54% of the cases various complications were noticed-very long ischemia, necrosis and spontaneous detachment of the autografts injury of the superficial (endothelial) layer of blood vessels. Thrombosis of blood vessels, tissue haemorrhage, bleeding of the contact areas, wound infections, stenosis of the tubular autografts, unknown cases of abnormalities and mortality could also take place. There are a so-called split or detached contact within the oesophagus and the ileum graft as well as a lowering and enlargement of the villi, atypical crypts, partial replacement of the epithelium columnar cells with goblet cells, inflammatory lymphocytic infiltration of propria and epithelium, high phagocytic activity of the macrophages. The transplant changes can be more rapid if the defect of the cervical oesophagus is filled with a small intestine patch. At the junction of the morphological picture a strong hypo- and atrophy can be observed as well as the destruction and irritation, complete replacement of the columnar cells with mucous cells. In the so-called resorptive contact typical epitheliocytes have been replaced by a polymorphic cell mass. Acute inflammatory infiltration penetrated regionally all over the transplant. The simple columnar epithelium of the ileus transplant has been replaced by the non-keratinized stratified squamous epithelium.