Histological research on the effect of viruses on wound healing

The influence of pure virus solution on wound healing was studied in animals. The rate of disturbed wound healing was proportional to the concentration of the virus solution. Severe necrosis without inflammatory reaction could be demonstrated histologically.     

Biology of chronic radiation effect on tissues and wound healing

Radiation therapy exerts both acute and chronic effects on normal tissue included within treatment fields. The physics of radiation therapy and treatment techniques to minimize deleterious effects of radiation are presented. Management of radiation-damaged skin is discussed. Radiation effect on tissue, wound healing, and tumorigenesis also are reviewed.     

The effect of different way of using FGF on wound healing

The UVU1 CHO cell line, a double mutant of the excision repair complementation group 1 UV4 cell line was characterized by a higher UV sensitivity than its parent (Busch et al (1989) Mutagenesis 4, 349-354). We show here that this mutant is not affected in a UV mutagenic pathway. In addition, the UVU1 cell line is about two-fold more sensitive to N-methyl-N'-nitro-N-nitrosoguanidine treatment than its parent without being more sensitive to cross-linking agents or ionizing radiations.     

The effect of prednisolone on the systemic response and wound healing after colonic surgery

To study the effect of preoperative treatment with a single high-dose of glucocorticoid on the systemic and immunological response, wound healing, and convalescence after colonic surgery, thirty patients were double-blind randomized to receive either methylprednisolone 30 mg/kg intravenously 90 minutes prior to induction of anaesthesia (group 1, n = 12), or to receive placebo (group 2, n = 12). Six patients were excluded from the study. Assessments of pain, pulmonary function, convalescence, various injury and wound-healing factors were done until 10 days after surgery. Conventional reduction in pulmonary function and mobilization was improved in group 1. Interleukin-6 and C-reactive protein levels increased significantly less in group 1, as delayed-type hypersensitivity was abolished in group 1. Plasma cascade system activation was significantly less pronounced in group 1. Reduction of collagen turnover was observed in group 1, but without detrimental effect on collagen accumulation. It is concluded that treatment with a single high dose of glucocorticoid before colonic surgery may improve postoperative pulmonary function and mobilization and reduce plasma cascade system activations, the inflammatory response, and immunofunction, but without detrimental effects on wound healing.     

Effect of norepinephrine on gastric wound healing

Lavage of the stomach with norepinephrine has been suggested as a temporary means of controlling upper gastrointestinal tract bleeding. The effect of norepinephrine on the healing of a standard gastric incision in the rat was studied using irrigation topically. When compared with those rats in the control study that were irrigated with a saline solution alone, no significant difference was found in the tensile strength, local inflammatory response or synthesis of new collagen, as determined by the hydroxyproline-proline ratio. There would appear to be no adverse effect on gastric wound healing as a result of preliminary irrigation of the gastric mucosa with norepinephrine given topically in a concentration of 16 milligrams per liter.     

Nutrition and wound healing

This paper reviews evidence that suggests malnutrition exists among the sick population in hospital and at home, a situation that has not improved in 20 years. It examines the consequences of malnutrition in broad terms and its effect on wound healing. The role of specific nutrients for wound healing is discussed, and finally the barriers which prevent nurses from delivering adequate patient nutrition are exposed.     

General principles of wound healing

Wound healing is a complex process involving different biologic and immunologic systems. Despite improvements in diagnostics and therapy, wound failures remain a clinical problem. The approach to a nonhealed wound is an interdisciplinary challenge that should not be underestimated. Better understanding of the complex wound-healing cascade helps our approach to wound healing and its possible failure. Manipulations of the involved immunologic features offer future therapeutic strategies.     

Nutritional aspects of wound healing

The nutritional aspects of wound healing include completing a nutritional assessment, estimating a patient's nutrient needs, and evaluating options for medical nutrition therapy. Some key nutrients involved in wound healing are discussed and their food sources described.     

Ultrastructural study of the skin after facial chemical peels and the effect of moisturization on wound healing

Ultrastructural changes occurring in the skin at early times after chemical peels as well as effects on the wound healing with moisturization after these peels have been examined. This study evaluated the changes seen in the skin 3 days and 5 days after 35% trichloroacetic acid peels, and the effect of moisturization on this healing was evaluated. Biopsies at 3 days showed an outermost layer of necrotic stratum corneum and stratum granulosum and an underlying layer of new stratum corneum. There were increased cytoplasmic vacuoles in the keratinocytes of the stratum spinosum, stratum granulosum, and stratum basale layers. There was extensive intercellular spacing between the basal keratinocytes. At 5 days the necrotic layer of stratum corneum and stratum granulosum was gone. The lower epidermis at 5 days showed less intercellular spacing, and there was less vacuolization within keratinocytes. In seven of eight patients treated with moisturization after the peel (p = 0.0325), the ultrastructural changes at 5 days were consistent with a more advanced state of healing compared with those that were treated dry. Ultrastructural morphology at this time showed less intercellular spacing and fewer cytoplasmic vacuoles, indicative of an advanced state of wound repair. These moisturized skin specimens had returned to an almost normal state of structure compared with the skin that had been treated dry.     

Nitric oxide regulates wound healing

Nitric oxide (NO) synthesis occurs during wound healing, but its role has not been defined. To study the effect of NO on wound repair, S-methyl isothiouronium (MITU, a competitive inhibitor of NO synthase) was administered at a dose of 10, 50, and 100 mg/kg body weight/day, using intraperitoneally implanted miniosmotic pumps. Groups of 10 male Balb/C mice underwent a dorsal skin incision and polyvinyl alcohol sponges were inserted subcutaneously. The animals were sacrificed 10 days postwounding and wound breaking strength and hydroxyproline content of sponges, an index of reparative collagen deposition, were determined. Some sponges were used to harvest wound fluid and infiltrating cells, which were then incubated overnight with or without 1 mM MITU. Nitrite and nitrate, stable end products of NO, were measured in wound fluid and in wound cell culture supernatants. Continuous intraperitoneal infusion of MITU significantly decreased wound fluid nitrite/nitrate concentrations in a dose dependent manner (P < 0.01). Inhibition of wound NO synthesis by 100 mg MITU/kg/day was paralleled by lowered wound collagen accumulation (P < 0.01) and wound breaking strength (P < 0.01). In vitro NO synthesis by wound cells obtained from animals treated with 100 mg MITU/kg/day was not significantly different from controls (12.6 +/- 1.2 vs 10.7 +/- 0.6 nmole NO2 + NO3/microgram DNA), reflecting the reversible inhibition of NO synthase by MITU. However, NO production was equally inhibited in wound infiltrating cells by the in vitro addition of MITU (83% vs 85%, respectively). These data suggest that nitric oxide synthesis is critical to wound collagen accumulation and acquisition of mechanical strength.     

The effect of octreotide on wound healing: an in vitro and in vivo experimental study

OBJECTIVE: To investigate the effect of octreotide on wound healing. DESIGN: Experimental studies in vitro and in rats. SETTING: Teaching hospital, Israel. MATERIAL: Cultured human diploid fetal fibroblasts, and 36 male Wistar rats. INTERVENTIONS: Octreotide was added to cultures of fibroblasts in doses of 2, 10, 30, 60 and 120 ng/ml and fibroblasts were counted after 2, 4, and 6 days. Intestinal anastomoses were made in 36 rats. Rats in the octreotide group (n = 18) were given subcutaneous injections of 0.25 microg/kg twice daily and 6 rats were killed at 3, 7, and 14 days. The control group were given injections of saline. Anastomotic bursting pressures and hydroxyproline content were measured at each of the three times. MAIN OUTCOME MEASURES: Fibroblast counts, anastomotic bursting pressures, and hydroxyproline concentrations. RESULTS: Octreotide did not inhibit fibroblast proliferation in any of the doses at any of the time periods. The anastomotic bursting pressure was slightly higher in the octreotide group at each of the time points, but not significantly so, and there was no difference in hydroxyproline content between the octreotide and control groups. Octreotide did not inhibit wound healing either in vitro or in vivo.     

Molecular studies in flexor tendon wound healing: the role of basic fibroblast growth factor gene expression

Basic fibroblast growth factor (bFGF) is a cytokine that plays a fundamental role in angiogenesis. This study examines bFGF messenger RNA (mRNA) expression in a rabbit flexor tendon wound healing model. Thirty-four New Zealand white rabbit forepaws underwent transection and repair of the middle digit flexor digitorum profundus tendon in zone II. Tendons were harvested at increasing time intervals and analyzed by in situ hybridization and immunohistochemistry. Few tenocytes and tendon sheath cells expressed bFGF mRNA in unwounded tendons. In contrast, tendons subjected to transection and repair exhibited an increased signal for bFGF mRNA in both resident tenocytes concentrated along the epitenon and infiltrating fibroblasts and inflammatory cells from the tendon sheath. These data demonstrate that (1) normal tenocytes and tendon sheath cells are capable of bFGF production, (2) bFGF mRNA is upregulated in the tendon wound environment, and (3) the upregulation of this angiogenic cytokine occurs in tenocytes as well as in tendon sheath fibroblasts and inflammatory cells.     

Fetal tissue repair and wound healing

The fibrosis and scar formation that characterize adult wound healing are also the cause of clinical problems; scar contracture, hypertrophic scar, and pulmonary and hepatic fibrosis are only a few examples. Studies of fetal wound healing can provide an insight into the initiation and regulation of a scarless repair process akin to regeneration. Studies of fetal repair have already suggested mechanisms that might favorably alter adult healing. Topical application of hyaluronic acid to wounds in adult diabetic rats leads to enhanced epithelial migration. It has been recognized that the addition of TGF-beta to fetal wounds causes an adultlike healing response with fibrosis and inflammation. A subsequent study using neutralizing antibody to TGF-beta in adult wounds showed enhanced healing with a more normal dermal architecture with fewer macrophages, fewer blood vessels, and less collagen. As our understanding of regenerative tissue repair increases, the opportunities to modulate adult fibrotic conditions should expand.