Effect of topical phenytoin on burn wound healing in rats

To evaluate the effect of phenytoin on burn wounds and to compare the effect of the combination of topical phenytoin preparation in dexamethasone treated burn wounds in rats, partial thickness thermal burn wounds were inflicted upon five groups of six rats each. Group I was assigned as control, Group II received the standard silver sulphadiazine, Group III was given topical phenytoin and Group IV received injection dexamethasone, Group V received the combination of the phenytoin and the dexamethasone. The parameters observed were epithelialization period, percentage of wound contraction and histopathological analysis as indicative of the process of healing. Phenytoin group showed significant improvement in burn wound contraction in comparison to standard silver sulphadiazine group, the combination group of topical phenytoin and dexamethasone also showed significant contraction compared to dexamethasone group. The period of epithelialization also decreased significantly in groups II, III and V. In conclusion, phenytoin promotes burn wound healing as evidenced by decrease in period of epithelialization and faster wound contraction.     

Enhanced wound contraction and epithelization period in steroid treated rats: role of pyramid environment

Contribution and role of a pyramid/square box on the wound healing suppressant effect of dexamethasone was studied in rats of either sex using excision wound model to record the wound contraction rate and epithelization period. The results showed enhanced wound contraction rate and decreased epithelization period in the pyramid-exposed rats as compared to controls. Thus, it appears that pyramid environment facilitates the process of wound healing. Also, the wound healing suppressant effects of dexamethasone were significantly reduced.     

Colonic healing after portal ischemia and reperfusion: an experimental study with oxidative stress biomarkers

This experimental study aimed to evaluate colon healing after portal ischemia followed by reperfusion. Seventy male Wistar rats randomly distributed in four groups were used: Group 1, colonic anastomosis (n = 20); Group 2, portal ischemia-reperfusion (n = 20); Group 3, colonic anastomosis and portal ischemia-reperfusion (n = 20); and Group 4, control (n = 10). In the postoperative period, these rats were re-allocated into subgroups and lipid peroxidation and protein oxidation plasma levels were evaluated on days 1 and 5 by thiobarbituric acid reactive substances (TBARS) and slot-blotting assays, respectively. A segment of the right colon was also removed for collagen analysis. Both malondialdehyde (MDA) and protein carbonyl levels (oxidative markers of lipids and proteins) presented a significant increase after reperfusion in Group 3 on days 1 (P < 0.002) and 5 (P < 0.0001). In this same group, an extensive inflammatory process showing decreased fibroplasia was observed, with deficiency in collagen deposition on both sides of the anastomosis edges. Taken together, these results indicate that portal congestion followed by reperfusion induces an oxidative stress, which impaired the mechanism of colon anastomotic healing.     

Effect of Ocimum sanctum Linn. on normal and dexamethasone suppressed wound healing

Ethanolic extract of leaves of O. sanctum was investigated for normal wound healing and dexamethasone depressed healing using incision, excision and dead space wound models in albino rats. The extract of O. sanctum significantly increased the wound breaking strength in incision wound model. The extract treated wounds were found to epithelialize faster and the rate of wound contraction was significantly increased as compared to control wounds. Significant increase in wet and dry granulation tissue weight, granulation tissue breaking strength and hydroxyproline content in dead space wound model was observed. The extract significantly decreased the antihealing activities of dexamethasone in all the wound models. The results indicated that the leaf extract promotes wound healing significantly and able to overcome the wound healing suppressing action of dexamethasone. Histological examination of granulation tissue to determine the pattern of lay-down for collagen confirmed the results.     

Pyramid environment reduces the wound healing suppressant properties of dexamethasone in albino rats

With a view to investigate the contribution and role of environment within a wooden pyramid model on the wound healing suppressant effect of dexamethasone in rats, wound breaking strength, dry weight, hydroxyproline content and histology of granulation tissue of the dead space wound were studied in rats. The results indicate that the environment within the wooden pyramid not only promotes significant wound healing but also reduces the wound healing suppressant effect of dexamethasone. Histological studies also confirmed the results.     

Effect of a honey and arginine-glutamine-hydroxymethylbutyrate mixture on the healing of colon anastomosis in rats immunosuppressed with tacrolimus

ABSTRACT

We compared the effect of honey and a mixture of arginine-glutamine-hydroxymethylbutyrate (AGHMB) on healing of a descending colon anastomosis in rats that were immunosuppressed with tacrolimus (Tac). Sprague-Dawley rats were divided into four groups: untreated control, Tac, Tac + honey and Tac + AGHMB. Colon resection and anastomosis were performed on day 14 and re-laparotomy was performed on the day 21 of the study. Anastomotic bursting pressure, macroscopic adhesion score, weekly body weight changes, histopathological features and immunohistochemical staining of TGF-β1 were determined for all groups. We found no significant difference in anastomotic bursting pressure among the experimental groups. We found significant weekly increases in body weight for the Tac + honey group. We found no significant difference in the weekly body weight measurements for the Tac + AGHMB group. We found significant increases in TGF-β1 expression in the Tac + honey group compared to the control and Tac groups. No significant differences in inflammatory cell infiltration, fibroblast proliferation or collagen deposition were found between the Tac + honey and Tac + AGHMB groups; however, a significant difference in neovascularization between these groups was found. Neovascularization in the Tac + honey group was significantly greater than for the Tac + AGHMB group. We found that both honey and the AGHMB mixture were beneficial for anastomotic wound healing in rats that were immunosuppressed using Tac.     

Does the light of soft lasers or of combination soft and middle-power lasers improve wound healing in rats? Continuing studies

In recent years, soft and middle-power lasers have been employed in the treatment of wounds and various dermatoses, but as yet no experimental confirmation of their effects has come available. However, we have been able to show in a recent study that light from combined soft and middle-power lasers applied on postoperative days 1, 2, 3, 5 and 8 has a positive effect on wound healing in rats. The present study was intended to clarify the influence of the type of laser light and treatment duration under controlled conditions. In 24 rats, a 3-cm incision was made in the abdominal wall and sutured with 5 single knots. Eight of the animals served as controls, while the remaining animals were treated with laser light, 8 with a soft laser for 10 min/day on postoperative days 2, 3, 5, 8 and 15, the other 8 for 20 min. on day 1 only with combined soft and middle-power lasers. The wounds were photographed on post-operative days 1, 2, 3, 5, 8 and 15. 10 independent observers rated the photographs on a scale of 1 to 4 on the basis of edge approximation and absence of inflammation. Soft laser light alone did not improve wound healing as judged by these criteria. Nor did a single dose of combined soft and middle-power laser light have any statistically significant effect.     

Colonic healing after portal ischemia and reperfusion: an experimental study with oxidative stress biomarkers

Abstract

This experimental study aimed to evaluate colon healing after portal ischemia followed by reperfusion. Seventy male Wistar rats randomly distributed in four groups were used: Group 1, colonic anastomosis (n = 20); Group 2, portal ischemia-reperfusion (n = 20); Group 3, colonic anastomosis and portal ischemia-reperfusion (n = 20); and Group 4, control (n = 10). In the postoperative period, these rats were re-allocated into subgroups and lipid peroxidation and protein oxidation plasma levels were evaluated on days 1 and 5 by thiobarbituric acid reactive substances (TBARS) and slot-blotting assays, respectively. A segment of the right colon was also removed for collagen analysis. Both malondialdehyde (MDA) and protein carbonyl levels (oxidative markers of lipids and proteins) presented a significant increase after reperfusion in Group 3 on days 1 (P < 0.002) and 5 (P < 0.0001). In this same group, an extensive inflammatory process showing decreased fibroplasia was observed, with deficiency in collagen deposition on both sides of the anastomosis edges. Taken together, these results indicate that portal congestion followed by reperfusion induces an oxidative stress, which impaired the mechanism of colon anastomotic healing.     

Wound healing potential of ethanolic extract of Kalanchoe pinnata Lam. leaf--a preliminary study

The extract of K. pinnata was evaluated for its wound healing activity by using excision wound model in rats. On day 11, animals treated with the ethanolic leaf extract exhibited 86.33% reduction in the wound area, compared to petroleum jelly treated control (69.36%) and the mupirocin treated standard (85.49%). The hydroxyproline content of extract treated animals was higher, as compared to control and the standard groups. Histological analysis was also consistent with the proposal that K. pinnata leaf extract exhibits significant wound healing potential. The increased rate of wound contraction and hydroxyproline content in the extract treated animals supports the claims made by traditional healers of the benefits obtained from the medicinal use of K. pinnata.     

Curcumin differentially regulates TGF-beta1, its receptors and nitric oxide synthase during impaired wound healing

Wound healing is a highly ordered process, requiring complex and coordinated interactions involving peptide growth factors of which transforming growth factor-beta (TGF-beta) is one of the most important. Nitric oxide is also an important factor in healing and its production is regulated by inducible nitric oxide synthase (iNOS). We have earlier shown that curcumin (diferuloylmethane), a natural product obtained from the plant Curcuma longa, enhances cutaneous wound healing in normal and diabetic rats. In this study, we have investigated the effect of curcumin treatment by topical application in dexamethasone-impaired cutaneous healing in a full thickness punch wound model in rats. We assessed healing in terms of histology, morphometry, and collagenization on the fourth and seventh days post-wounding and analyzed the regulation of TGF-beta1, its receptors type I (tIrc) and type II (tIIrc) and iNOS. Curcumin significantly accelerated healing of wounds with or without dexamethasone treatment as revealed by a reduction in the wound width and gap length compared to controls. Curcumin treatment resulted in the enhanced expression of TGF-beta1 and TGF-beta tIIrc in both normal and impaired healing wounds as revealed by immunohistochemistry. Macrophages in the wound bed showed an enhanced expression of TGF-beta1 mRNA in curcumin treated wounds as evidenced by in situ hybridization. However, enhanced expression of TGF-beta tIrc by curcumin treatment observed only in dexamethasone-impaired wounds at the 7th day post-wounding. iNOS levels were increased following curcumin treatment in unimpaired wounds, but not so in the dexamethasone-impaired wounds. The study indicates an enhancement in dexamethasone impaired wound repair by topical curcumin and its differential regulatory effect on TGF-beta1, it's receptors and iNOS in this cutaneous wound-healing model.     

The effects of topical treatment with curcumin on burn wound healing in rats

The present study was designed to determine the role of topical treatment with curcumin (Cur) on burn wound healing in rats. The Wistar-albino rats were randomly allotted into one of three experimental groups: 4th, 8th and 12th day (post burn) and all groups include subgroups which Burn and Burn + Cur. Each group contains 12 animals. Burn wounds were made on the back of rat and Cur was administered topically. At the end of the study, all animals were sacrificed and the wound tissues removed for analyse to biochemical and histopathological changes. There was a significant increase in the hydroxyproline levels in the skin of the Cur groups. Cur treated wounds were found to heal much faster as indicated by improved rates of inflammatory cells, collagen deposition, angiogenesis, granulation tissue formation and epithelialization which were also confirmed by histopathological and biochemical examinations. Our data also indicate that there is a rise in the expression of proliferating cell nuclear antigen in skin tissues of Cur-treated rats in the Burn group. The results clearly substantiate the beneficial effects of the topical application of Cur in the acceleration of wound healing.     

创伤合并海水浸泡后愈合过程的病理学观察

目的观察创伤合并海水浸泡后对伤口愈合时间的影响及愈合过程中的病理学改变。方法以大鼠为实验动物,建立背部双侧圆形创伤模型,创后随机分为对照组和实验组,每组50只,实验组创后置海水中浸泡30min。观察2组创面的愈合生长状况。观察伤口局部愈合过程中的病理学改变,应用免疫组化方法观察愈合过程中伤口修复细胞增殖指数及微血管密度变化。结果对照组平均愈合时间为（12.0±1.0）d,而实验组的平均愈合时间为（14.3±0.8）d;两组在肉芽组织形成时间上以及修复细胞增殖能力上存在差异。结论创伤合并海水浸泡可导致伤口愈合时间延迟,加重创伤局部的炎症反应、延缓肉芽组织形成时间。     

The Effect of Mesenchymal Stem Cells and Chitosan Gel on Full Thickness Skin Wound Healing in Albino Rats: Histological,Immunohistochemical and Fluorescent Study

Background

Wound healing involves the integration of complex biological processes. Several studies examined numerous approaches to enhance wound healing and to minimize its related morbidity. Both chitosan and mesenchymal stem cells (MSCs) were used in treating skin wounds. The aim of the current work was to compare MSCs versus chitosan in wound healing, evaluate the most efficient route of administration of MSCs, either intradermal or systemic injection, and elicit the mechanisms inducing epidermal and dermal cell regeneration using histological, immunohistochemical and fluorescent techniques.

Material and Methods

Forty adult male Sprague Dawley albino rats were divided into four equal groups (ten rats in each group): control group (Group I); full thickness surgical skin wound model, Group II: Wound and chitosan gel. Group III: Wound treated with systemic injection of MSCs and Group IV: Wound treated with intradermal injection of MSCs. The healing ulcer was examined on day 3, 5, 10 and 15 for gross morphological evaluation and on day 10 and 15 for histological, immunohistochemical and fluorescent studies.

Results

Chitosan was proved to promote wound healing more than the control group but none of their wound reached complete closure. Better and faster healing of wounds in MSCs treated groups were manifested more than the control or chitosan treated groups. It was found that the intradermal route of administration of stem cells enhanced the rate of healing of skin wounds better than the systemic administration to the extent that, by the end of the fifteenth day of the experiment, the wounds were completely healed in all rats of this group. Histologically, the wound areas of group IV were hardly demarcated from the adjacent normal skin and showed complete regeneration of the epidermis, dermis, hypodermis and underlying muscle fibers. Collagen fibers were arranged in many directions, with significant increase in their area percent, surrounding fully regenerated hair follicles and sebaceous glands in the dermis of the healed areas more than in other groups.

Conclusion

MSCs enhanced the healing process of wound closure more than chitosan gel treatment. Furthermore, MSCs injected intradermally, were more efficient in accelerating wound healing than any other mode of treatment.     

Promotion of wound healing by yeast glucan evaluated on single animals

The effectiveness of yeast glucan in the acceleration of wound healing was evaluated in mice, rats and guinea pigs. In all experiments comparison between glucan treatment in one hind leg and saline treatment as control on the other leg was made on identical wounds. The degree of healing in the two legs was evaluated macroscopically and classified as follows: 1. healing more advanced in glucan treated wound marked by (+). 2. No significant difference between the two legs marked by (0). 3. Healing more advanced in the control wound, marked by (-). During the days when the differences were most obvious, 60% to 80% of the animals showed more advanced healing in the glucan treated wound, 20% to 40% showed no significant difference; and 0 to 15% showed more advanced healing in the control, saline treated wound. The average time for complete wound healing was reduced by about 18% as a result of glucan treatment. The histological analysis shows that the acceleration of wound healing was mediated by early arrival of macrophages to the wound area in the glucan treated wounds.     

EGF and TGF-alpha in wound healing and repair

Wound healing is a localized process which involves inflammation, wound cell migration and mitosis, neovascularization, and regeneration of the extracellular matrix. Recent data suggest the actions of wound cells may be regulated by local production of peptide growth factors which influence wound cells through autocrine and paracrine mechanisms. Two peptide growth factors which may play important roles in normal wound healing in tissues such as skin, cornea, and gastrointestinal tract are the structurally related peptides epidermal growth factor (EGF) and transforming growth factor alpha (TGF-alpha). EGF/TGF-alpha receptors are expressed by many types of cells including skin keratinocytes, fibroblasts, vascular endothelial cells, and epithelial cells of the GI tract. In addition, EGF or TGF-alpha are synthesized by several cells involved in wound healing including platelets, keratinocytes, and activated macrophages. Healing of a variety of wounds in animals and patients was enhanced by treatment with EGF or TGF-alpha. Epidermal regeneration of partial thickness burns on pigs or dermatome wounds on patients was accelerated with topical application of EGF or TGF-alpha, and EGF treatment accelerated healing of gastroduodenal ulcers. EGF also increased tensile strength of skin incisions in rats and corneal incisions in rabbits, cats, and primates. Additional research is needed to better define the roles of EGF, TGF-alpha and their receptor in normal wound healing, to determine if alterations have occurred in the EGF/TGF-alpha system in chronic wounds, and optimize vehicles for effective delivery of peptide growth factors to wounds.     

The effect of finger millet feeding on the early responses during the process of wound healing in diabetic rats

In the present study, the role of finger millet feeding on skin antioxidant status, nerve growth factor (NGF) production and wound healing parameters in healing impaired early diabetic rats is reported. Hyperglycemic rats received food containing 50 g/100 g finger millet (FM). Non-diabetic controls and diabetic controls received balanced nutritive diet. Full-thickness excision skin wounds were made after 2 weeks prior feeding of finger millet diet. The rate of wound contraction, and the levels of collagen, hexosamine and uronic acid in the granulation tissue were determined. The skin antioxidant status and lipid peroxide concentration were also monitored during the study. In hyperglycemic rats fed with finger millet diet, the healing process was hastened with an increased rate of wound contraction. Skin levels of glutathione (GSH), ascorbic acid and alpha-tocopherol in alloxan-induced diabetic rat were lower as compared to non-diabetics. Altered activities of superoxide dismutase (SOD) and catalase (CAT) were also recorded in diabetics. Interestingly, thiobarbituric acid reactive substances (TBARS) were elevated in the wound tissues of all the groups, when compared to normal (unwounded) skin tissues. However, in diabetic rats the TBARS levels of both normal and wounded skin tissues were significantly elevated (P < 0.001) when compared with control (non-diabetic) and diabetics fed with FM. Impaired production of NGF, determined by ELISA, in diabetic rats was improved upon FM feeding and further confirmed by immunocytochemical observations reflects the increased expression of NGF in hyperglycemic rats supplemented with FM-enriched diet. Histological and electron microscopical evaluations revealed the epithelialization, increased synthesis of collagen, activation of fibroblasts and mast cells in FM-fed animals. Thus, increased levels of oxidative stress markers accompanied by decreased levels of antioxidants play a vital role in delaying wound healing in diabetic rats. However, FM feeding to the diabetic animals, for 4 weeks, controlled the glucose levels and improved the antioxidant status, which hastened the dermal wound healing process.     

Time-dependent expression and distribution of Egr-1 during skeletal muscle wound healing in rats

Recent studies have shown that early growth response factor-1 (Egr-1) plays an important role in regulation of inflammation and tissue repair, but little is known about its expression after trauma to skeletal muscles. A preliminary study on time-dependent expression and distribution of Egr-1 was performed by immunohistochemistry, immunofluorescence and Western blotting during skeletal muscle wound healing in rats. An animal model of skeletal muscle contusion was established in 45 Sprague-Dawley male rats. Samples were taken at 6 h, 12 h, 1 day, 3 days, 5 days, 7 days, 10 days, 14 days and 21 days post-injury, respectively (5 rats in each posttraumatic interval). 5 rats were employed as control. In the uninjured controls, Egr-1 positive staining was observed in the sarcoplasm and nuclei of normal myofibers. In wounded specimens, a small number of polymorphonuclear cells (PMNs), a number of mononuclear cells (MNCs), fibroblastic cells (FBCs) and regenerated multinucleated myotubes showed positive reaction for Egr-1 in contused zones. By morphometric analysis, an increase in Egr-1 expression was verified at inflammatory phase after contusion, which reached a peak in the regenerated phase overlapping with the fibrotic phase during skeletal muscle wound healing. The expression tendency was further confirmed by Western blotting assay. By immunofluorescent staining for co-localization, the Egr-1-positive MNCs and FBCs in wounds were identified as macrophages and myofibroblasts. The results demonstrate that the expression of Egr-1 is up-regulated and temporally distributed in certain cell types after trauma to skeletal muscles, which may be closely involved in inflammatory response, fibrotic repair and muscle regeneration during skeletal muscle wound healing.     

股前外侧穿支皮瓣与胸腹带蒂皮瓣对手外伤组织缺损修复的应用效果及对创面愈合程度的影响

摘要 目的：探讨股前外侧穿支皮瓣与胸腹带蒂皮瓣对手外伤组织缺损修复的应用效果及对创面愈合程度的影响。方法：选取我院2018年12月到2020年12月共收治的119例手外伤组织缺损患者作为研究对象,随机分为2组,分别为对照组（n=59,应用胸腹带蒂皮瓣修复术）和观察组（n=60,应用股前外侧穿支皮瓣修复术）。对比两组患者治疗优良率,对比两组患者治疗前后手部创面面积、创面愈合程度以及组织愈合时间,对比两组患者治疗后的Jamar握力、TAM和DASH评分情况,对比两组患者的皮瓣成活率、皮瓣危象率和血管吻合时间。结果：通过对比两组患者治疗优良率发现,观察组患者优的人数为21例、良为35例,优良率为93.33%,对照组患者优的人数为16例,良为30例,优良率为77.97%,观察组高于对照组（P＜0.05）;治疗后,与对照组相比,观察组患者的手部创面面积、组织愈合时间和DASH评分显著减少,创面愈合程度以及TAM与Jamar握力显著增加（P＜0.05）;通过对比两组患者的皮瓣成活率、术后皮瓣危象率以及血管吻合时间发现,两组患者的术后皮瓣危象率、血管吻合时间对比无明显差异（P＞0.05）,两组患者的术后皮瓣成活率对比差异显著,观察组明显高于对照组（P＜0.05）。结论：对手外伤组织缺损患者应用股前外侧穿支皮瓣与胸腹带蒂皮瓣修复术均具有明显的修复效果,但是应用股前外侧穿支皮瓣能够提升治疗效果,提升患者创面愈合程度减少愈合时间,提升患者手部运动情况,提升术后皮瓣成活率,值得临床应用推广。     

Pulsed electromagnetic fields accelerate wound healing in the skin of diabetic rats

Delayed wound healing is a common complication in diabetes mellitus. From this point of view, the main purpose of the present study is to investigate the effect of extremely low frequency pulsed electromagnetic fields (ELF PEMFs) on skin wound healing in diabetic rats. In this study, diabetes was induced in male Wistar rats via a single subcutaneous injection of 65 mg/kg streptozocin (freshly dissolved in sterile saline, 0.9%). One month after the induction of diabetes, a full‐thickness dermal incision (35 mm length) was made on the right side of the paravertebral region. The wound was exposed to ELF PEMF (20 Hz, 4 ms, 8 mT) for 1 h per day. Wound healing was evaluated by measuring surface area, percentage of healing, duration of healing, and wound tensile strength. Obtained results showed that the duration of wound healing in diabetic rats in comparison with the control group was significantly increased. In contrast, the rate of healing in diabetic rats receiving PEMF was significantly greater than in the diabetic control group. The wound tensile strength also was significantly greater than the control animals. In addition, the duration of wound healing in the control group receiving PEMF was less than the sham group. Based on the above‐mentioned results we concluded that this study provides some evidence to support the use of ELF PEMFs to accelerate diabetic wound healing. Further research is needed to determine the PEMF mechanisms in acceleration of wound healing in diabetic rats. Bioelectromagnetics 31:318–323, 2010. © 2010 Wiley‐Liss, Inc.