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Biomedical subjects

G W Cherry

Publications and source records attributed to G W Cherry.

At least 55 records · Page 3Linked to original sources
PubMed1984

Enhancement of skin-flap survival using nitroglycerin ointment.

Rat and pig skin flaps were used to investigate the effects of topical nitroglycerin ointment on flap survival. Significant increase in flap survival was detected and correlated well with plasma nitroglycerin levels measured during the treatment regimen. The drug was applied 1 hour preoperatively in both models. Recent experimental clinical investigations on the use of pharmacologics for treating failing flaps were reviewed, including the possible mechanism of action of nitroglycerin. Characteristics of an ideal pharmacologic agent for use in the treatment of failing flaps were delineated. Further investigation is warranted to determine the effects of nitroglycerin ointment on various other flaps, including musculocutaneous and free flaps, as well as timing of these applications. All these variables could best be studied in the pig with confirmation of other researchers prior to advocating clinical usage. Until then, the ideal pharmacologic agent for prevention of skin-flap necrosis remains unknown.

Administration, Topical↗
PubMed1984

The rat cradle.

Explore the source record for details and available documents.

Animals↗
PubMed1983

Ultrastructure of mast cells in growing and involuting stages of hemangiomas.

Mast cells from 11 patients with growing strawberry (capillary) hemangiomas and cellular hemangiomas and from ten patients with involuting stages of strawberry hemangiomas were investigated electron microscopically. Two types of mast cells were evident: numerous elongated, fibroblastic cells and a few round, classic cells. The mast cells in growing hemangiomas contained many small, simple-type granules in various stages of development. It is possible that, owing to the immaturity of these granules, mast cells have different, probably weaker, functional activities. Mast cells in involuting stages of hemangiomas were filled primarily with compound-type granules, showing typical parallel, concentric lamellae or crystalloid structures, which were similar to the mature mast cells in normal skin.

Female↗
PubMed1983

Increased survival and vascularity of random-pattern skin flaps elevated in controlled, expanded skin.

Controlled clinical tissue expansion, a new technique of providing donor tissue, results in an increase in surface area of expanded skin. The aim of the present study was to determine the effect of controlled tissue expansion on the surviving lengths of random-pattern skin flaps elevated in expanded tissue. In five pigs the surviving lengths of flaps raised in skin expanded for 5 weeks using a 250-cc rectangular Radovan-type tissue expander were compared with the survival lengths of flaps elevated in tissue in which a similar prosthesis was not expanded, bipedicle flaps delayed for 5 weeks, and control acutely raised random-pattern flaps. The expanded flaps had a mean increase in surviving length of 117 percent over control flaps, which was statistically significant. The delay flaps had an increase in survival of 73 percent over control flaps, which was also statistically significant. There was no significant difference in survival between expanded flaps and delayed flaps. Morphologic studies using radiographic techniques on one pig demonstrated increased vascularity with tissue expansion. The results of this work demonstrate that in addition to providing increased surface area with controlled expansion, flaps raised in expanded skin have a significantly augmented surviving length. The mechanism for this increased vascularity with expansion is not known at this time, but it may be due to physical forces associated with expansion acting as a stimulus for angiogenesis.

Animals↗
PubMed1983

The importance of elastic fibres in skin lymphatics.

Elastic fibres lie in intimate contact with dermal lymphatics. Demonstration of elastic by an orcein stain enables lymphatics to be identified and differentiated from blood capillaries. The finding of elastic suggests it plays an important role in the normal functioning of lymphatics.

Animals↗
PubMed1983

Crystalloid inclusions in endothelial cells of cellular and capillary hemangiomas. A possible sign of cellular immaturity.

The fine structure of crystalloid inclusions were found in the endothelial cells of capillary (strawberry) hemangiomas and cellular hemangiomas in nine infants. The inclusions measured from 0.5 to 2.0 microns in diameter and showed parallel lamellar bands with a regular periodicity of about 180 to 300 A. The presence of crystalloid inclusions and the absence of typical rod-shaped tubulated Weibel-Palade bodies suggest the immaturity and embryonic character of the endothelium present in the blood vessels of these kinds of hemangiomas.

Crystallization↗
PubMed1982

Cellular haemangioma. Light and electron microscopic studies of two cases.

Light and electron microscopic studies were conducted on the immature vascular tumors of two infants, containing various stages of differentiation of the blood vessels and both benign haemangioendotheliomas and haemangiopericytomas. We were able to confirm the existence of two kinds of hyperplastic, immature cells i.e. endothelial cells and pericytes in the same tumor. Presence of crystalloid inclusions in the endothelial cells and absence of the Weibel-Palade bodies, as well as a deficiency in factor VIII-related antigen and no tissue fibrinolytic activity, suggested that the endothelial cells in these lesions were immature. Electron microscopic studies appear more decisive in the diagnosis of heterogenous cellular vascular tumors than light microscopy and if available should be used to aid in the final diagnosis. The authors propose that the term cellular haemangioma would be more appropriate in describing this vascular entity.

Antigens↗
PubMed1982

Electron microscopic evaluation of guinea pig skin and soft tissues "expanded" with a self-inflating silicone implant.

An electron microscopic study of guinea pig skin and soft tissue after expansion by self-inflating silicone implant for periods of 7 weeks to 8 months revealed definite ultrastructural changes. In the epidermis, the cells of the malpighian layer contained larger groups of tonofilaments forming tonofibrils. Intercellular spaces in all layers of expanded epidermis were much more reduced than in normal epidermis. The basal lamina and the laminar surfaces of the basal cells demonstrated more undulation than those of the controls. The expanded dermis contained large bundles of compacted collagen fibers, as well as thin collagen fibers, active fibroblasts, and a few myofibroblasts. The subcutaneous tissue contained a paucity of adipose tissue and thickened collagen fibers in the interlobular spaces. The skeletal muscle showed larger amounts of sarcoplasm in relation to myofibrils. An increased number and size of mitochondria were found with sarcomeres abnormally arranged. The capsule around the implant was composed of active, elongated, and flattened fibroblasts and bundles of collagen fibers with variable fiber width. Intracellular collagen fibers were found in the cytoplasm of the fibroblasts. Myofibroblasts in the capsule were observed more often in early expanded tissue. Small blood vessels in the capsule showed multiplication of the basal lamina or were surrounded by a very wide, homogenous material. Inflammatory cells were not found in the capsule. Such findings are important in developing and evaluating future skin-expansion research in humans and animals.

Adipose Tissue↗
PubMed1982

Histomorphologic evaluation of guinea pig skin and soft tissue after controlled tissue expansion.

To evaluate the histologic changes attendant on tissue expansion in the guinea pig, self-inflating implants were placed in the dorsal subcutaneous space and the tissue response was sequentially studied at periods ranging from 1 to 18 weeks. Fixation artifacts have been minimized. The cellular response is relatively benign. The epidermis does not undergo thinning during expansion, although dermis and panniculus carnosus become significantly thinner. Atrophy of panniculus muscle is demonstrable. This study supports the hypothesis that tissue expansion results in a net gain of donor tissue.

Animals↗
PubMed1979

The effects of gravity on delayed and transplanted delayed tubed flaps.

Altering the position (elevated or dependent) had no immediate effect on the blood supply of delayed or transplanted delayed tubed flaps. However, after 72 hours the mean survival length in the dependent tubes was less than that in the elevated tubes. (This difference was only significant in the delayed untransplanted flaps, and not so in the delayed transplanted flaps). All of the dependent tubes had a significant increase in water content (compared to the elevated tubes). This increase was greater in the transplanted delayed tubed flaps. The tissue pCO2 levels were significantly increased after 24 hours in the dependent transplanted tubes, reflecting poor circulation and ischemia in them. The rate of clearance of subcutaneously injected technetium-99m was significantly increased in the dependent transplanted tubes after 72 hours, while in the elevated tubes the clearance rate was similar to that in normal skin. The morphological appearance of the vessels in these flaps complemented the results of the functional study.

Animals↗
PubMed1979

The differing effects of isoxsuprine on muscle flap and skin flap survival in the pig.

The pretreatment of pigs with isoxsuprine for two weeks resulted in a significant increase in the surviving length of sartorius muscle flaps when compared with untreated flaps on the same animal. However, there was no improvement in the surviving length of neurovascular island skin flaps when these animals were treated with isoxsuprine. The difference in these results is thought to be due to the action of isoxsuprine on the blood supply of skeletal muscle.

Animals↗
PubMed1975

Decreased myocardial fibrinolytic activity following temporary ischaemia and reperfusion.

The effect of temporary myocardial ischaemia (x 52 mins) and reperfusion (x 23 hrs 8 mins) on myocardial tissue fibrinolysis and 125I fibrinogen incorporation into fibrin was investigated in nine baboons. Fibrinolytic activity was reduced by 54% in the endocardium of the ischaemic reperfused myocardium and the 125I fibrinogen activity was elevated by 480%. The reduction in myocardial fibrinolytic activity following ischaemia and reperfusion may be due to endothelial damage.

Animals↗