PubMed Health⌕ Search

Biomedical subjects

S C Davis

Publications and source records attributed to S C Davis.

27 records · Page 2Linked to original sources
PubMed1988

Optimal use of an occlusive dressing to enhance healing. Effect of delayed application and early removal on wound healing.

We examined the effect of delayed application and early removal of a polyurethane dressing on excisional wounds in swine. Backs of pigs were wounded with an electrokeratome, and wounds were divided into the following treatment groups: (1) air exposed; (2) dressings applied immediately after wounding and kept on until wounds were evaluated; (3) dressings applied immediately after wounding and removed at 6, 24, or 48 hours; and (4) dressings applied 2, 6, and 24 hours after wounding. Wounds were excised on days 3 through 7 and incubated in sodium bromide to allow separation of the epidermis and dermis. Specimens were considered healed if no defect was present. To promote optimal resurfacing in superficial wounds, polyurethane dressings need to be applied within two hours after wounding and should be kept in place for at least a 24-hour period.

Animals↗
PubMed1985

Right heart assist by intermittent abdominal compression after surgery for congenital heart disease.

Right heart assist after open heart surgery in children can be accomplished by inflation of a balloon beneath a tight cloth wrap on the abdomen. This device can be inexpensively constructed of ordinary equipment found in the intensive care unit. This is a review of the use of intermittent abdominal compression in 14 children (mean age 19 +/- 15 months, mean weight 8 +/- 4 kg) after operation at Henrietta Egleston Hospital. Primary diagnoses were tricuspid atresia physiology in five, atrioventricular canal in four, truncus arteriosus in one, tetralogy of Fallot in one, ventricular septal defect (VSD) in one, D-transposition of the great arteries in one, and aortic-left ventricular tunnel with VSD in one. Compression was used for an average of 16.3 +/- 11.4 hr. Displacement of blood from the abdominal viscera to the central circulation by balloon inflation led to elevation of right atrial pressure by 3.6 +/- 1.8 mm Hg (p less than .001) and consequent elevation of mean arterial pressure by 9.8 +/- 5 mm Hg (p less than .001). Urine output was improved in almost every instance. In 11 surviving children, the net fluid intake and output balance in the first 12 hr after application of intermittent abdominal compression was -154 +/- 219 ml (p less than .05). This simple method of intermittent abdominal compression was effective after a variety of operations for treatment of congenital heart disease and was especially useful after the Fontan procedure.

Cardiac Output↗
PubMed1981

Ruptured hepatic artery aneurysm with hepatic artery-to-portal vein fistula. Preservation of portal flow by autogenous vein reconstruction.

Hepatic artery aneurysms are uncommon lesions that have varied clinical presentations. Rupture into the portal vein has occasionally been reported, as has associated gastrointestinal bleeding. A case is described in which an unusually large hepatic artery aneurysm ruptured into the portal vein, destroying a major portion of its wall. Reconstruction was accomplished successfully by use of an autogenous saphenous vein patch with preservation of hepatopetal portal flow.

Aged↗
PubMedDate not supplied

Cholesterol phosphate derivatives: synthesis and incorporation into a phosphatase and calcium-sensitive triggered release liposome.

A series of cholesterol derivatives that position a phosphate monoester at increasing distance from the sterol ring system was synthesized, and their utility as a triggered release liposome tested. Stable anionic liposomes consisting of the novel cholesterol phosphate derivatives and dioleoylphosphatidylethanolamine (DOPE) can be induced to collapse upon phosphatase-catalyzed removal of the phosphate group. Control liposomes containing DOPE and cholesterol phosphate or phosphatidic acid, which are not phosphatase substrates, do not undergo phosphatase-mediated collapse. The phosphatase-sensitive liposomes also collapse in the presence of calcium. The precise concentration of calcium that induces the collapse is controlled by the structure of the cholesterol phosphate derivative. Plasmid DNA encoding luciferase, encapsulated in the cholesterol derivative/DOPE liposomes, transfected cells in vitro. The level of transfection is dependent upon the cholesterol derivative and is mediated by both a calcium-independent and a calcium-dependent pathway; however, the involvement of phosphatase in the latter mechanism is not yet resolved. The transfection efficiency is between 10(6) and 10(7) of luciferase activity in relative light units per milligram of protein, which is similar to transfection values reported using other triggered release liposomes.

Alkaline Phosphatase↗
PubMedDate not supplied

Effect of ultraviolet radiation-induced inflammation on epidermal wound healing.

To examine the influence of ultraviolet radiation, a potent inducer of interleukin-1 and other growth factors, on the rate of epidermal migration, we used a porcine model of wound healing. Wounds were treated in one of the following treatment groups: (1) two minimal erythema doses of ultraviolet radiation once daily for 2 days before wounding, (2) two minimal erythema doses of ultraviolet radiation once daily for 2 days before wounding followed with continuous treatment until all wounds were 100% epithelized, (3) or no ultraviolet radiation treatment until healing was complete. Using a macroscopic salt-split technique, we examined epidermal specimens macroscopically for epithelialization. Treatment both before and after ultraviolet radiation significantly enhanced epithelialization when compared with non-ultraviolet radiation-treated control wounds. These experiments show that ultraviolet radiation treatment can augment the rate of healing of partial-thickness wounds.

Journal Article↗
PubMedDate not supplied

The pig as a model for human wound healing.

The medical literature describes numerous in vitro and in vivo wound-healing models. The selection of an animal model depends on a number of factors including availability, cost, ease of handling, investigator familiarity, and anatomical/functional similarity to humans. Small mammals are frequently used for wound healing studies, however, these mammals differ from humans in a number of anatomical and physiological ways. Anatomically and physiologically, pig skin is more similar to human skin. The many similarities between man and pig would lead one to believe that the pig should make an excellent animal model for human wound healing. The purpose of this paper is to review the existing literature for evidence of this supposition and determine how well the various models correlate to human wound healing. Studies of wound dressings, topical antimicrobials, and growth factors are examined. Over 180 articles were utilized for this comparative review. Our conclusion is that the porcine model is an excellent tool for the evaluation of therapeutic agents destined for use in human wounds.

Animals↗
PubMedDate not supplied

Effects of an arginine-glycine-aspartic acid peptide-containing artificial matrix on epithelial migration in vitro and experimental second-degree burn wound healing in vivo.

Cells central to dermal tissue repair such as dermal fibroblasts and keratinocytes interact with arginine-glycine-aspartic acid (RGD)-containing proteins of the extracellular matrix such as fibronectin. It has been shown that synthetic peptides containing this RGD sequence can also support cell attachment and migration in vitro. We therefore set out to test whether the use of these peptides, when formulated as a synthetic RGD-peptide matrix consisting of peptide complexed with hyaluronic acid, would have an effect on the rate of epithelial migration and healing of experimental wounds. Evaluation consisted of measuring he extent of epithelial outgrowth from human dermal explants and the epithelization of experimental second-degree burn wounds in pigs. We show here that the RGD-peptide matrix supports epithelial sheet migration from explants in a dose-dependent manner. In second-degree burn wounds in pigs, wounds treated with daily applications of the RGD-peptide matrix under occlusion resurfaced at a significantly faster rate (day 7 = 57% completely epithelized) than wounds treated with hyaluronic acid under occlusion (day 7 = 13% completely epithelized, p < 0.01), occlusion alone (day 7 = 13% completely epithelized, p < 0.01), or air exposed (day 7 = 0% completely epithelized, p < 0.001). Histologic examination showed that wounds treated with the RGD-peptide matrix also had thicker epithelial covering and greater granulation tissue deposition than occluded, air-exposed, and hyaluronate-treated wounds. These data therefore show that the use of RGD-peptide matrix induces faster explant epithelial migration and results in faster healing of experimental second-degree burns.

Animals↗
PubMedDate not supplied

Early debridement of second-degree burn wounds enhances the rate of epithelization--an animal model to evaluate burn wound therapies.

The purpose of this study was to examine the rate of epithelization of second-degree burn wounds with use of two debridement times (early versus late). Burn wounds were randomly assigned to one of the following treatment groups: (1) control, no debridement, (2) early debridement at 24 hours after burning, or (3) late debridement at 96 hours after burning. Wounds from each treatment group were harvested, incubated to allow separation of the dermis and epidermis, and then examined macroscopically for complete epithelization. On day 7 after burning, the percentage of burn wounds completely epithelized was as follows: nondebrided, 41%, 24-hour early debridement, 75%, and 96-hour late debridement, 22%. Burn wounds that were excised 24 hours after burning enhanced the rate of healing as compared to 96 hour and nondebrided burn wounds.

Animals↗