Changes of the dermal-fascial autograft after transplantation on the vascular-nervous connections using a microsurgical technique

In 56 dogs 86 microsurgical operations on transplantation of free dermal-facial autografts from the internal knee surface have been performed on the hidden vascular-nervous bundle. The animals have been observed for 1 day up to 1 year. The implanted grafts (63) have been studied, using a complex of anatomical, histological and roentgenological methods. During early time (up to 7 days) after the operation in the flap signs of edema, dystrophy and inflammatory infiltration of tissues predominate. The graft gets blood at the expense of the restored main artery and has no vascular connections with the surrounding tissues. Its nervous conductors are fragmented. During 2 weeks--1 month epidermis completely regenerates along the line of the dermal suture. In the flap bed mature granulations result in vascular connections with its surrounding tissues. These connections become stable by the end of the first month, this means that the graft has implanted. Its nervous fibers are also restored. Long-term observations demonstrate that the adaptive changes of the flap and its vascular bed are near to completion. By the end of the 1st year restoration of the main innervational connections of the graft takes place. According to the data obtained, the nervous conductors grow into it along the sewed hidden nerve and along the course of paravasal nerve plexuses. Across the scar from the surrounding tissues the dermal-fascial autograft does not reinnervate.     

Replantation of fingertip amputation by using the pocket principle in adults

There are several treatment modalities for zone 1 or zone 2 fingertip amputations that cannot be replanted by using microsurgical techniques, such as delayed secondary healing, stump revision, skin graft, local flaps, distant flaps, and composite graft. Among these, composite graft of the amputated digit tip is the only possible means of achieving a full-length digit with a normal nail complex. The pocket principle can provide an extra blood supply for survival of the composite graft of the amputated finger by enlarging the area of vascular contact. The surgery was performed in two stages. The amputated digit was debrided, deepithelialized, and reattached to the proximal stump. The reattached finger was inserted into the abdominal pocket. About 3 weeks later, the finger was removed from the pocket and covered with a skin graft. We have consecutively replanted 29 fingers in 25 adult patients with fingertip amputations by using the pocket principle. All were complete amputations with crushing or avulsion injuries. Average age was 33.64 years, and men were predominant. The right hand, the dominant one, was more frequently injured, with the middle finger being the most commonly injured. Of the 29 fingers, 16 (55.2 percent) survived completely and 10 (34.5 percent) had partial necrosis less than one-quarter of the length of the amputated part. The results of the above 26 fingers were satisfactory from both functional and cosmetic aspects. Twenty of the 29 fingers, which had been followed up for more than 6 months (an average of 16 months), were included in a sensory evaluation. Fifteen of these 20 fingers (75 percent) were classified as "good" (static two-point discrimination of less than 8 mm and normal use). From the overall results and our experience, we suggest that the pocket principle is a safe and valuable method in replantation of zone 1 or zone 2 fingertip amputation, an alternative to microvascular replantation, even in adults.     

Evaluation of premeiotic activity in the developing rabbit testis using a modified squash technique

Germ cells in the developing rabbit testis were studied using a modified squash technique. Preleptotene figures present in the postnatal testis were examined and compared with corresponding stages in ovarian germ cells. The findings indicated differences in the pattern of preleptotene changes in the developing ovary and testis.     

Developmental pattern of testosterone production by the rat testis

We studied the steroidogenic activity of isolated Leydig ceils derived from rats on fetal day 19 (F₁₉) and postnatal (N) days 1, 12, 24, 34, 45 and adults. Leydig cells, isolated at all ages by the collagenase method, increased in number throughout development with a doubling time of 8 days. Testicular content and serum concentrations of testosterone showed parallel changes during development. Moderate values were found at the early stages (F₁₉ and N₁), with a nadir on day 12, followed by a progressive increment to reach maximal values in adulthood. A reduction in steroidogenic activity of the testis during neonatal life was confirmed by urlar|_vitro studies with isolated Leydig cells. Maximal activity was found in group F₉; testosterone production diminished after birth to reach a minimum in group N₃₄ and rose thereafter to adulthood. Leydig cells were responsive to hCG stimulation at all ages in the following order: N₁>N₃₄>N₁₂>F₁₉>N₂₄>N₄₅>adult. The present study demonstrates the existence of an active and hCG-responsive population of Leydig cells in the rat testis from fetal life to adulthood.     

Metabolism of testosterone by preparations from the rat testis

Seminiferous tubules isolated from immature and adult rats were incubated with [¹⁴C] testosterone. Androstanediol and androstenedione were the major metabolites; dihydrotestosterone and androsterone were produced in lesser amounts. Cell suspensions of spermatocytes prepared from tubules of immature rats formed dihydrotestosterone as the major metabolite of testosterone. Smaller amounts of androstanediol were formed and no androsterone was detectable. The results show that spermatocytes in common with androgen responsive tissues have the capacity to metabolize testosterone to 5α-reduced products.