Renato Pinto Gonçalves

Influence of autonomic denervation upon the kinetics of the ileal epithelium of the rat

SummaryThe effect of autonomic denervation upon the kinetics of the ileal epithelium of rats was studied by tracing 3H-thymidine labelled nuclei and counting mitotic figures and goblet cells. Counts of labelled nuclei and goblet cells provided information about cell migration along the intestinal epithelium. The mitotic index and turnover time of this population were calculated from the mitotic figures counts. Comparing denervated animals with sham operated controls, it was possible to conclude that autonomic denervation, either sympathectomy or parasympathectomy results in a decrease in mitotic activity. As a result of lower mitotic activity in the crypts, the turnover time increases and there is a delay in the migration of cells from the crypts towards the villi. Sympathectomy causes an early short-lived effect upon the kinetics of the crypt cell population, since after 27 h there is a tendency to normality. Parasympathectomy produces a slower but continuous decline in mitotic activity.

Fresh immature articular cartilage allografts

SummaryThe integration of immature cartilage allografts to knee joints of both normal rabbits and those submitted to arthritis through papain was studied for a period of up to 9 months.Two types of grafts were compared: chondral—constituted only by cartilage, and osteochondral—cartilage plus a thin layer of subchondral bone.The integration of the grafts was analyzed through inspection of the articular surface and histologic sections.The viability of the grafts was checked through the incorporation of 35SO4 on the chondral matrix.The following conclusions were drawn:(1)A large member of the grafted cartilages were well accepted without histological evidence of immunological rejection, and metabolically active 9 months after transplantation.(2)The chondral graft was found to be superior to the osteochondral one regarding the integration, but both showed tendency to degeneration with time.(3)The presence of arthritis previously induced by papain affected the integration of the grafts causing a higher percentage of degeneration on the grafted cartilage.ZusammenfassungÜber einen Zeitraum bis zu 9 Monaten wurde die Integration unreifer Knorpel-Allotransplantate in den Kniegelenken normaler Ratten und solcher, bei denen mittels Papain Arthritis hervorgerufen wurde, beobachtet.Es wurde ein Vergleich zwischen zwei Transplantatarten aufgestellt: 1. chondralen — bestehend aus nur einem Knorpel und 2. osteochondralen — bestehend aus einem Knorpel plus einer dünnen Schicht aus subchondralem Knochen.Die Integration der Transplantate wurde analysiert durch Inspektion der Gelenkoberfläche und der histologischen Abschnitte.Die Lebensdauer der Transplantate wurde durch Eingeben von 35SO4 in die Knorpelmatrize getestet.Folgende Schlußfolgerungen wurden gezogen:1.Ein Großteil der Knorpeltransplantate wurde gut aufgenommen, ohne histologischen Beweis für immunologische Abwehr, und war metabolisch noch nach 9 Monaten aktiv.2.Das chondrale Transplantat integrierte sich besser als das osteochondrale, beide neigten jedoch mit der Zeit zu Degenerationserscheinungen.3.Die zuvor mittels Papain hervorgerufene Arthritis beeinträchtigte die Integration der Transplantate und rief einen größeren Prozentsatz an degenerierten Knorpeltransplantaten hervor.