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Biomedical subjects

S F Swaim

Publications and source records attributed to S F Swaim.

At least 19 recordsLinked to original sources
PubMed2001

Effects of a bioactive glass on healing of closed skin wounds in dogs.

OBJECTIVE: To determine effects of intraincisional bioactive glass on healing of sutured skin wounds in dogs. ANIMALS: 9 purpose-bred mature female Beagles. PROCEDURE: 3 small matched bilateral (treated vs control) full-thickness truncal skin incisions were made and sutured. Treated wounds received intraincisional particulate bioactive glass prior to closure. Laser Doppler perfusion imaging was used to assess percentage change in tissue perfusion 3 and 5 days after incision on 1 set of 2 matched wounds, and skin and subcutaneous tissue-cutaneous trunci breaking strength were assessed at 5 days. The other 2 sets of wounds were used for histologic evaluation at 5 and 21 days, respectively. RESULTS: Subjective signs of gross inflammatory reaction were not detected in treated or control wounds. At 5 days, median subcutaneous tissue-cutaneous trunci breaking strength was significantly higher in treated wounds than in control wounds-(188.75 vs 75.00 g). At 5 days, median scores were significantly higher for neutrophils (1 vs 0), macrophages (2 vs 1), and necrosis (1 vs 0) for treated wounds than for control wounds. At 21 days, median macrophage scores were significantly higher for treated wounds than for control wounds (2 vs 1). CONCLUSIONS AND CLINICAL RELEVANCE: Bioactive glass in soft tissues does not cause a gross inflammatory reaction but causes an increase in histologic signs of inflammation, which decreases with time. Bioactive glass has potential for increasing tissue strength. Increased subcutaneous breaking strength could be beneficial in treating wounds in which early healing strength is needed.

Animals↗
PubMed2000

Effects of a hydrolyzed collagen dressing on the healing of open wounds in dogs.

OBJECTIVE: To determine the effects of a hydrolyzed bovine collagen dressing (HBCD) on healing of open wounds in healthy dogs. ANIMALS: 9 female Beagles. PROCEDURES: 2 full-thickness skin wounds were made bilaterally on the trunk of each dog. Wounds on 1 side were treated with powdered HBCD covered with a semiocclusive nonadherent bandage. Wounds on the other side (control wounds) were covered with a semiocclusive nonadherent bandage only. Wound healing was subjectively assessed, and percentage increase in tissue perfusion was assessed by use of laser Doppler perfusion imaging (LDPI). Planimetry was performed to determine the percentages of contraction, epithelialization, and total wound healing. Biopsy specimens were examined microscopically to evaluate histologic changes. RESULTS: The HBCD did not induce a strong inflammatory reaction, as reflected by results of LDPI and histologic examination. Moreover, HBCD appeared hydrophilic and provided an environment to keep wounds clean and enhance early epithelialization. After treatment for 7 days, treated wounds had a significantly greater percentage of epithelialization than control wounds (12.13 vs. 7.03%). CONCLUSION AND CLINICAL RELEVANCE: The hydrophilic property of HBCD may cleanse contaminated wounds with the body's homeostatic fluids and enhance early wound epithelialization.

Animals↗
PubMed1999

Evaluation of fibrin sealants in cutaneous wound closure.

Human fibrin sealant (HFS) and bovine fibrin sealant (BFS) were delivered as preformulated fibrinogen-thrombin mixtures that are light activated. These formulations were evaluated in the healing of incised cutaneous wounds in beagle dogs. Four groups were differentiated by sealant type and study duration with group: BFS for 10 days, HFS for 10 days, BFS for 30 days, and HFS for 30 days. Healing was evaluated by noting incidences of open wounds, laser Doppler perfusion imaging (LDPI), planimetry, breaking strength, and histopathology. In the absence of tension, both sealants tended to hold wound edges together; however, HFS tended to be better than its controls and BFS. Both sealants augmented suture closure, necessitating fewer sutures for wound closure. At 5 and 30 days BFS wounds had more perfusion than HFS wounds, indicating more inflammation. At 10 and 30 days BFS wounds had larger scar areas than their controls, while scar areas of HFS wounds were smaller than either BFS wounds or controls. Breaking strengths indicated that HFS wounds were stronger than their controls and BFS wounds. Histologically, mild to moderate chronic-active inflammation was observed in wounds receiving either sealant, and this persisted longer in BFS wounds. Overall, HFS had positive qualities, thus showing potential for functional and cosmetic wound closure.

Animals↗
PubMed1998

Evaluation of the effects of omega-3 fatty acid-containing diets on the inflammatory stage of wound healing in dogs.

OBJECTIVES: To ascertain the effects of dietary omega-3 (n-3) fatty acids on biochemical and histopathologic components of the inflammatory stage of wound healing. ANIMALS: 30 purpose-bred Beagles. PROCEDURE: Dogs were allotted to 5 groups of 6. Each group was fed a unique dietary fatty acid ratio of omega-6 to n-3--diet A, 5.3:1; diet B, 10.4:1; diet C, 24.1:1; diet D, 51.6:1; and diet E, 95.8:1. Dogs were fed once daily for 12 weeks, then biopsy specimens were taken from 4-day-old wounds of each dog and analyzed by gas chromatography-mass spectrometry for: prostaglandin E2 (PGE2) metabolites, and ratios of omega-6 to n-3 fatty acids, arachidonic acid (AA) to eicosapentaenoic acid (EPA), adrenic acid to docosahexaenoic acid, and PGE2 to prostaglandin E3 (PGE3) metabolites. RESULTS: Qualitative analysis was carried out on AA, EPA, adrenic acid, docosahexaenoic acid, and the major metabolite from the PGE2 and PGE3 pathway. These molecules were further quantified with respect to diet to determine significant differences. By analysis of the AA-to-EPA ratio, diet A was different from diets D and E and diets B and C were different from diet E (P < 0.05). By analysis of the PGE2-to-PGE3 metabolite ratio, diet A was different from diet E (P < 0.05). Though biochemical analysis indicated dietary dependence, histopathologic data indicated no significant difference with respect to diet groups. CONCLUSION: The biochemical component of the inflammatory stage of wound healing can be manipulated by diet. CLINICAL RELEVANCE: Omega-3 fatty acid-enriched diets can be used to control inflammation associated with dermatologic conditions.

Animals↗
PubMed1998

Evaluation of treatment with a pulsed electromagnetic field on wound healing, clinicopathologic variables, and central nervous system activity of dogs.

OBJECTIVE: To evaluate effects of treatment with a pulsed electromagnetic field (PEMF) on healing of open and sutured wounds, clinicopathologic variables, and CNS activity of dogs. ANIMALS: 12 adult female Beagles. PROCEDURE: Open and sutured wounds were created in the skin of the trunk of the dogs. Dogs were divided into 2 groups. One group received PEMF treatment and 1 group served as untreated (control) dogs. The PEMF-treated dogs received treatment twice a day starting the day before surgery and lasting through day 21 after surgery. Wounds were evaluated by use of tensiometry, planimetry, laser Doppler perfusion imaging, and histologic examination. Clinicopathologic variables and electroencephalographic tracings were also evaluated. RESULTS: Use of PEMF treatment resulted in significantly enhanced epithelialization of open wounds 10 and 15 days after surgery. Five days after surgery, wounds of control dogs had a negative value for wound contraction, whereas PEMF-treated wounds had a positive value. The PEMF treatment did not cause significant changes in short-term planimetric, perfusion, tensiometric, histologic, clinicopathologic, or electroencephalographic results. CONCLUSIONS: The PEMF treatment enhanced wound epithelialization in open cutaneous wounds and provided indications of early contraction without significant short-term changes in other variables.

Animals↗
PubMed1996

Effect of locally injected medications on healing of pad wounds in dogs.

OBJECTIVE: To ascertain the effects of locally injected immunostimulant and tripeptide-copper complex (TCC) on improving healing of pad wounds. DESIGN: Wounds in pads of large dogs were injected with either medication or physiologic saline solution (controls). Healing was evaluated. ANIMALS: 12 mature English Pointers. PROCEDURE: Full-thickness 6 x 8-mm wounds in metatarsal and third and fourth digital pads were injected with immunostimulant or TCC at 0, 3, and 6 days after wounding. Wounds on control dogs were injected with physiologic saline solution. Using planimetric measurements at 0, 3, 6, 14, and 21 days, rates of healing were evaluated. Biopsy of the digital pad wounds at 3, 6, and 14 days was used to evaluate collagen content by hydroxyproline analysis. Biopsy specimens were also evaluated for type-I and type-III collagen, using Sirius red differential staining. RESULTS: Effect on healing rate and hydroxyproline content was best during the first week for immunostimulant. Immunostimulant- and TCC-injected wounds had more type-I collagen than did controls at 6 days; TCC-injected wounds had the most type-I collagen. At 14 days, the amount of type-I collagen in TCC-injected wounds was significantly greater than that in other wounds. CONCLUSIONS: Tested medications had positive effects on healing of pad wounds. CLINICAL RELEVANCE: Intralesional injection of medications helps ensure their presence for enhancement of wound healing. The benefit could be lost with topical use in a bandage if the bandage is lost or becomes wet.

Adjuvants, Immunologic↗
PubMed1995

Effects of three occlusive dressing materials on healing of full-thickness skin wounds in dogs.

The effects of 3 occlusive dressing materials and a standard, nonadherent dressing material on healing of full-thickness skin defects were evaluated in dogs. Two wounds measuring 2 x 2 cm were created bilaterally (4 wounds/dog) on the dorsolateral aspect of the trunk of 12 Beagles. Wound treatments were evenly distributed between 4 sites, using a Latin square design. Treatments evaluated were: equine amnion (group A), biosynthetic hydrogel dressing (group B), transparent polyethylene sheeting (group T), and a semi-occlusive rayon/polyethylene, nonadherent dressing (group C). Rates of contraction and epithelialization of group-A wounds were significantly greater than those of wounds of groups C, B, and T. On days 14, 21, and 28, mean percentage of wound contraction and mean percentage of total wound healed in group A exceeded those wounds in groups C, B, and T. On day 28, wounds in group A were significantly smaller than wounds in groups B and T, but were not significantly smaller than wounds in group C. All wounds in group A achieved 100% healing during the 28-day study period. Mean time for complete healing of group-A wounds was 21 days. The percentages of wounds completely healed by day 28 for groups B, C, and T were 25, 67, and 25%, respectively. Results indicate that use of equine amnion as an occlusive biological dressing on full-thickness wounds in dogs increases rate of healing.

Amnion↗
PubMed1993

Free segmental paw pad grafts in dogs.

After removal of 1 metatarsal pad and formation of a granulation tissue bed, free segmental 6- x 8-mm grafts from digital pads were sutured into recessed same-size recipient sites in the granulation tissue. In 5 dogs, the grafted area had been denervated by excision of a segment of the tibial nerve at the level of the tarsus. The grafted area was not denervated in the remaining 5 dogs. In both groups of dogs, the grafts placed around the periphery of the wound healed, blocked ingrowth of delicate epithelium from the surrounding skin, and provided a tough keratinized epithelium that covered the wound's center. As healing progressed, the grafts coalesced as the wounds contracted. Weight bearing resulted in graft expansion to provide functional weight-bearing tissue. Dogs of the denervated group had clinical and histologic evidence of collateral sensory reinnervation of the denervated area. However, with the exception of 1 dog, results of sensory nerve action potential tests indicated that reinnervation may not have been by way of regeneration across the excisional gap in the nerve. Evaluation of reinnervation of the tibial autonomous zone in 2 additional dogs revealed clinical evidence that collateral reinnervation began between 19 and 28 days after nerve excision and progressed proximad to distad. Results of sensory nerve action potential tests indicated that reinnervation may not have been via regeneration across the excision site. Results of fluorescent tracer studies did not have positive findings regarding the route of collateral reinnervation. Segmental paw pad grafts can be used effectively to provide weight-bearing tissue on a dog's limb. With local nerve damage on the distal portion of the limb, collateral innervation can grow into the area to reinnervate tissues, including pad grafts.

Animals↗
PubMed1993

The greyhound dog as a model for studying pressure ulcers.

Because of their angular conformation, short hair, and thin skin, greyhounds are particularly subject to development of pressure ulcers. Greyhounds, therefore, can serve as a model to study pressure ulcers, either naturally occurring pressure ulcers or induced dermal pressure lesions. A method for inducing dermal pressure lesions was developed using a short-limb walking cast on one pelvic limb of the dog. Physical characteristics, dermal thromboxane B2 concentrations, and histopathologic changes were used to determine the severity of the lesions. Different lesion severities can be induced over the calcaneal tuberosity depending upon the amount of padding in the cast and the length of time the cast is in place. The technique for inducing a mild dermal pressure lesion is described.

Animals↗
PubMed1992

Healing of segmental grafts of digital pad skin in dogs.

Pad grafts would be indicated in instances of severe paw trauma when there has been loss of the major weight-bearing pads (ie, metatarsal and metacarpal pads) as well as loss of the digital pads. A practical technique for replacing pad tissue on the remaining paw tissue could avert limb amputation for lack of weight-bearing tissue in the area. Small segmental digital pad grafts were placed in granulation tissue beds in dogs. Although the grafts were from thick pad skin, they healed well. However, intervening wound areas did not become covered with the heavier keratinized epithelium of the pads. The thinner, more rapidly growing, less keratinized epithelium from the wound edges covered most of the wound.

Animals↗
PubMed1992

Evaluation of the dermal effects of cast padding in coaptation casts on dogs.

Three configurations of cast padding and no cast padding were evaluated for their effects on skin in dogs. Padding was placed over bony prominences, between bony prominences, and over both areas for full-length padding under short-limb walking casts applied to 1 pelvic limb of Greyhounds. Evaluations were performed by pressure measurement over the calcaneal tuberosity, measurement of skin thromboxane B2 (TxB2) concentrations in skin over bony prominences, and measurement of plasma TxB2 concentrations. Pressure studies were performed to evaluate cutaneous pressures related to no cast padding and various configurations of cast padding. Concentrations of TxB2 in the skin were determined to evaluate the skin inflammatory effects of no padding and the padding configurations, and TxB2 concentrations in the plasma were analyzed to ascertain whether they could be used to predict impending dermal pressure lesions. Flexion of casted limbs revealed the greatest pressure over the calcaneal tuberosity with full-length cast padding. This was followed in decreasing order by no cast padding, padding over the prominences, and padding between the prominences. Compared with all other bony prominences and padding configurations, TxB2 skin concentrations were significantly higher over the calcaneal tuberosity when no padding was used and over the lateral base of metatarsal V when padding was placed between the prominences. Over the calcaneal tuberosity, this was attributed to the sharpness of the prominence and its potential for movement. This high TxB2 concentration corresponded to the high pressure found in the pressure studies. Over the lateral base of metatarsal V, the increase in TxB2 concentration was related to the mass of the prominence and the tendency for localized padding to settle around the area.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Evaluation of surgical scrub and antiseptic solutions for surgical preparation of canine paws.

The purpose of the prospective study reported here was to evaluate surgical preparation of canine paws. Three combinations of surgical scrub solutions and antiseptic solutions were used: (1) 7.5% povidone-iodine scrub/10% povidone-iodine solution; (2) 2% chlorhexidine acetate scrub/2% chlorhexidine diacetate solution; and (3) tincture of green soap/70% isopropyl alcohol. The control was warm (38 to 42 C) tap water. Four microbial colony counts were used to evaluate surgical preparation of 4 paws of 8 dogs. Specimens were obtained from the paws for a baseline microbial flora count. After surgical scrub was performed, additional specimens were obtained for bacteriologic culturing. Antiseptic was applied followed by collection of another specimen for bacteriologic culturing. A final specimen was obtained following a 24-hour period under a sterile occlusive bandage. The 3 scrub solutions and the tap water control resulted in lower colony counts following scrubbing of the paws; however, only the 3 antiseptic solutions resulted in further colony count reduction after their application. Evaluation of residual colony counts isolated from specimens taken after a 24-hour period under a sterile occlusive bandage revealed chlorhexidine and povidone-iodine scrub/antiseptic combinations to be similar in antibacterial activity, with significantly (P less than or equal to 0.05) lower colony counts than those from specimens of paws treated with either the tincture of green soap/isopropyl alcohol combination or the tap water control. The lack of a significant difference between the bacterial counts immediately after surgical preparation with povidone-iodine and chlorhexidine and their respective 24-hour residual counts, indicated no particular advantage to surgical preparation and occlusive bandaging 24 hours prior to surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Effects of amnion and live yeast cell derivative on second-intention healing in horses.

Equine amnion and live yeast cell derivative were evaluated as a biological dressing and as a topical wound medicament respectively, in the treatment of granulating wounds of the distal portion of the limbs of horses. Wounds measuring 2.5 x 2.5 cm were created on the dorsomedial aspect of the metacarpal and metatarsal region of all 4 limbs of 9 horses. Each wound was assigned randomly to 1 of 3 treatment groups: group C, treated with a nonadherent bandage as a control; group A, treated with amnion beneath a nonadherent bandage; and group L, treated with live yeast cell derivative beneath a nonadherent bandage. Rates of contraction and epithelialization were not significantly different among groups. Percentage of epithelialization for group A was significantly greater throughout the study than for the other groups. Number of days to complete healing was significantly less in group A and significantly greater in group L than in group C. Incidence and severity of exuberant granulation tissue were significantly less in group A than in the other 2 groups. Group L had more frequent and severe cases of exuberant granulation tissue than the other 2 groups.

Amnion↗
PubMed1990

Bandages and topical agents.

Bandages are included in the regimen of therapy of superficial wounds. Bandages have varying functions depending upon the type of wound to which they are applied. When bandaging recently inflicted open wounds, the primary bandage layer may be dry-to-dry, wet-to-dry, or wet-to-wet, depending upon the type of tissue and exudate present on the wound. These bandages aid in debriding and cleansing a wound. The secondary layer of such bandages serves primarily to absorb material from the wound, and the tertiary bandage layer serves to hold the other bandage layers in place. Once an open wound is well into the repair stage of healing, an occlusive bandage may be considered to help enhance epithelialization of the wound. Bandages for wounds associated with compound fractures must include some form of fixation for the fracture. Other types of bandages are designed to (1) cover closed wounds, (2) provide pressure over a wound, and (3) relieve pressure over wounds or impending wounds. Bandages for closed wounds provide protection and allow for absorption of exudate that may be present. Pressure bandages are used to control minor hemorrhage, edema, and excess granulation tissue. With impending decubital ulcers, actual decubital ulcers, or repaired decubital ulcers, it is necessary to have a bandage designed to relieve pressure over the lesion. Many substances have been described for topical application to wounds. This section presents information on some substances available to or commonly used by veterinarians. It includes information on the wound lavage solutions chlorhexidine diacetate, povidone-iodine, hydrogen peroxide, and sodium hypochlorite solutions. Topical antibacterial agents are used to help prevent wound infection. The triple antibiotics, silver sulfadiazine, nitrofurazones, and gentamicin sulfate are some commonly used antibacterial agents. Hydrophilic agents are used to diffuse fluids through the wound tissues to bathe the tissues from the inside. Dry starch copolymer flakes and dextran polymer beads are two substances that help bathe the wound with the body's own fluids. Other topical medications are used to selectively act upon various wound tissues and exudates to aid in cleansing the wound; these include organic acid preparations and enzymatic debriding agents. In addition, a live yeast-cell derivative has been described for enhancing tissue oxygen consumption, epithelialization, and collagen synthesis in wounds.

Administration, Topical↗
PubMed1990

Skin grafts.

Skin grafting is a method to reconstruct the skin covering on areas of the body where there are defects and insufficient surrounding skin for advancement or for creation of flaps. Grafts are classified according to their host-donor relationship and by their thickness. Autogenous grafts, taken from one area of the body and applied to another area, are the type of graft used most often clinically. Pieces of skin are taken from one area of the body, prepared and applied over a defect that has also been properly prepared to accept the graft. The defect to which a graft is applied must be a healthy bed of granulation tissue or tissue that is vascular enough to produce a bed of granulation tissue. In its new location, the graft will develop a new blood supply and attachment to underlying tissues. This is accomplished as the graft undergoes the processes of fibrinous adherence, plasmatic imbibition, inoculation, and new vessel ingrowth. The types of grafts described in this chapter are split-thickness, full-thickness, seed, strip, and stamp grafts. Each of these graft types must be prepared using certain techniques, and each one has its inherent advantages and disadvantages. Split-thickness grafts may require considerable skill and/or expensive equipment to perform. Although they "take" better than full-thickness grafts, they are usually less cosmetically attractive. Full-thickness grafts require no special skill or expensive equipment, and their cosmetic appearance is better than that of split-thickness grafts, but they do not take as well as split-thickness grafts. Seed and strip grafts are easily accomplished and require no special instruments; however, their cosmetic appearance is not good. Stamp grafts have some of the properties associated with split-thickness grafts as well as those of seed and strip grafts, since they combine features of both.

Animals↗
PubMed1989

Elevation of thromboxane in pressure wounds.

Arachidonic acid metabolites have been implicated as mediators of progressive dermal ischemia. Decubitus ulcer formation results from chronic mechanical pressure on the skin which results in a diminished blood supply to the skin and underlying tissues. To evaluate the role of thromboxanes in pressure wounds, we measured TxB2, a stable metabolite of TxA2, in spontaneously occurring pressure wounds on Greyhound dogs. In pressure wounds in which the skin was showing early signs of pressure necrosis but was still intact, elevated TxB2 concentrations were found in healthy appearing tissues immediately adjacent to the pressure wounds, in the inner edge of the wounds, and in the center of the wounds. Significantly greater TxB2 concentrations (P less than 0.05) were found in the center of the intact wounds versus the TxB2 concentrations in the inner edge of the wounds or in healthy appearing tissues adjacent to the wounds. In pressure wounds in which the center of the wound had ulcerated or had an eschar, elevated TxB2 concentrations were found in tissues in the inner edge of the wounds and in healthy appearing tissues immediately adjacent to the pressure wounds. These results demonstrate the occurrence of elevated thromboxane concentrations in and around spontaneously occurring pressure wounds.

Animals↗