Donald L. Ballantyne

Inosculation of vessels of skin graft and host bed: A fortuitous encounter

From the combined procedures of skin stereomicroscopy of in situ grafts in rats, graft removal and supravital intracardiac injection of a contrast medium, the data suggest that the revascularisation of skin grafts is an orderly sequence of events which include: active invasion of the graft dermis by the ingrowing host capillary sprouts; development of anastomoses between the graft and host vasculatures; entry of blood into the graft through the vascular anastomoses by 48 hours after transplantation.

THE RELATION OF HAIR CYCLES TO THE SURVIVAL TIME OF SUPRAPANNICULAR AND SUBPANNICULAR SKIN HOMOGRAFTS IN RATS

The cyclic growth of hair in young rats was demonstrated by Butcher (1934), who reported that the growth of hair follicles in the first cycle extends from birth to the 16th or 17th postnatal day and becomes inactive by the 22nd day. This inactivity, described as a quiescent or rest period, persists until the 32nd day, when active growth and lengthening of the hair follicles is resumed. We have attempted to correlate the cycles of hair growth in rats with the duration of skin homografts, acting on the hypothesis that if appreciable differences in survival time could be related to phases of the hair cycle, such variations would be of interest to workers in the field of tissue transplantation. Two types of skin grafts were used in homotransplantation. In one, the skin graft was removed from above the panniculus carnosus (suprapannicular grafts) ; in the other, the skin, together with the panniculus (subpannicular grafts), was removed. The relative survival time of each of these homografts was studied in this series of experiments.

INFLUENCE OF OXISURAN, A DIFFERENTIAL INHIBITOR OF CELL-MEDIATED HYPERSENSITIVITY, ON ALLOGRAFT SURVIVAL AND HUMORAL IMMUNITY

SUMMARY Oxisuran, 2-[(methylsulfinyl)acetyl]pyridine, has been shown to suppress allograft rejection in mice, rats, and dogs. Unlike 6-mercaptopurine or azathioprine, oxisuran does not concomitantly suppress humoral antibody production in mice or dogs. The compound is less active in the dog than in the rat, a finding consistent with the different metabolic pathways found in these two species. The toxicology of oxisuran and implications for mechanism of action are discussed.

Serum Complement Activity in Rat Recipients of Small and Massive Skin Allografts.

Summary The complement activity was determined in sera of recipients after reciprocal skin transplantation between two isogenic strains of BN and Lewis rats. Small or massive allografts did not significantly affect the pattern or the level of overall complement activity, despite the fact that these animal sera are known to bind complement in the cy to toxic reaction in vitro. A slight initial rise of the serum complement activity has been noted in most of the animals. This rise is attributed to a possible increase in production of serum protein elicited by bleeding. The results have been interpreted to rule out either an exhaustion or an inactivation of the complement system as a causative factor in the longevity of massive grafts.

SEROLOGIC REACTIONS TO SKIN HOMOGRAFTS OF VARIOUS SIZES IN THE RAT.

Althouph i t has been recently established that massive skin homografts extending over one-third of the body surface of the recipient rat survive longer than small little is known of the magnitude of the immunological response to these massive skin homotransplants. I t was suggested in a recent study4 that the prolonged survival of massive grafts might be due to antigenic “overloading” with consequent immunologic unresponsiveness. Ballantyne and Converse4 noted that second-set massive skin grafts in recipients previously sensitized by a first-set graft from the same donor exhibited prolonged survival, instead of undergoing accelerated rejection. It was further shown that massive grafts in adoptively immunized rats were not appreciably influenced by the passive transfer of sensitized regional lymph node cells, whereas small skin grafts in similarly conditioned animals underwent an accelerated homograft rejection reaction. One parameter of the immune response which is accessible to investigation and measurement is the cytotoxic activity in the sera of graft recipients. In this study, skin grafts have been exchanged between two widely unrelated isogenic rat strains (brown Norway and albino Lewis) and the antibody titers achieved by recipients of small, large, and massive grafts have been compared.

Eyelid deformities caused by the injection of silicone fluid

Summary Medical grade dimethylpolysiloxane (silicone) fluid has proved satisfactory as an injectable subcutaneous tissue prosthesis in the treatment of certain deformities such as hemifacial atrophy. The injection of this material beneath the eyelid skin can result in the formation of palpebral bags because of localisation of the tissue reaction and the thinness of the eyelid skin. Surgical excision of the localised silicone mass is indicated in some patients, although total excision is usually not possible. Patients with such eyelid lesions are presented.

Critical Closing Pressure, Local Perfusion Pressure, and the Failing Skin Flap

A simple apparatus was devised to perfuse the rat groin flap to study the relationship between perfusion pressure and flow. Results demonstrate that a relatively high intraarterial pressure must be applied to this skin flap before blood flow will commence. Results suggest that this critical closing phenomenon is the result of surface tension, blood rheology, venous pressure, tissue pressure, and vascular smooth muscle tone. Correlating the experiments of Milton and Landis reveals that, beyond a certain distance, local perfusion pressure in a skin flap gradually decreases with increasing distance from the flap base. These observations suggest that the perfusion boundary in a skin flap forms at the point where perfusion pressure has fallen to the level of the critical closing pressure. Methods of increasing survival length of a flap by decreasing critical closing pressure are discussed. The effects of edema and pressure dressings on flap and replant survival are examined in terms of the closing pressure concept.

Long-term skin preservation by combined use of tissue culture and freezing techniques.

Simple but effective methods for shipping newly excised rabbit skin to a distant central laboratory for in vitro culture on a pigskin base, followed by freezing in a cryoprotective agent (DMSO) for frozen storage and subsequent reshipment to the originating laboratory while still frozen are described. At a suitable time the frozen tissue was rapidly thawed and transplanted to the autologous recipient rabbit. Of 12 cultures, seven indicated good to excellent cell growth and maturation on the host. The successful method combined the use of in vitro tissue culture and freezing to permit a central laboratory to grow the skin and ship it to the originating center for autografting at a convenient time.

Massive rabbit skin xenografts in rats.

SUMMARY While several recent studies (2-5,7, 12, 14, 15) in rats have shown that massive allografts survive longer than small grafts, nothing is known concerning the survival of massive skin xenografts. Experiments were designed to ascertain whether an analogous mechanism exists in the massive skin xenografts transferred from rabbits to rats. Full thickness massive skin grafts, 50-65 cm2, taken from rabbit flanks and auricles were applied to prepared recipient beds of 30 rats and 30 other rats received small grafts measuring 0.25-1.0 cm2, Periodical gross and stereomicroseopic observations were made to evaluate the behavior and fate of all grafts, with particular attention to the graft vasculature. The findings indicated that massive grafts survived twice as long as the small ones, similar to the findings described for massive allografts in rats. Of particular interest was the evidence showing re-establishment of the definitive vasculature with active blood flow in xenografts of both sizes. A peculiar form of chronic rejection is noted in massive transplants and an attempt is made to explain this rejection.

Vascular changes in the suprapannicular skin wounds in rats

Abstract Vascular regeneration of suprapannicular skin defects in rats was evaluated using an injection technique, with particular reference to the early stages of vascular processes. The comparative studies suggest that the vascular regeneration in suprapannicular wounds, originating in highly vascular tissue, is more distinct than in subpannicular wounds.