Healthy Granulation Research Articles

The Use of Platelet-Rich Fibrin for Immediate Closure of Acute Oroantral Communications: An Alternative Approach

Currently, the buccal advancement flap, palatal rotational flap, and buccal fat pad techniques are frequently used to close an oroantral communication (OAC). In this study, platelet-rich fibrin (PRF) clots were used for immediate closure of acute OACs after extraction of posterior maxillary molars. Acute oroantral perforations larger than 3mm in diameter in 21 patients were treated uneventfully using PRF clots. None of the patients had systemic diseases or symptoms of sinus disease. After tooth extraction, the diagnosis of acute OAC was examined by the Valsalva maneuver (compressing the nostrils with the fingers and then blowing out air). After detection of an air leak, a modified ball burnisher instrument 3mm in diameter was used to determine whether the perforation was larger than 3mm. The postextraction socket of the tooth was cleaned with sterile physiologic saline solution and the cavity was filled with PRF. PRF clots were sutured to the gingiva to prevent them from migrating to the sinus and for stabilization. On the seventh day of follow-up, healthy granulation tissue was observed; during the third week of follow-up, epithelialized oral mucosa was detected at the extraction site in all cases. The use of PRF enables the closure of OACs without primary flap closure or any other surgical interventions. Thus, the use of PRF for immediate closure of acute OACs will make the treatment of OACs less traumatic and easier and will eliminate the need for special surgical expertise.

A comparative study of collagenase ointment versus povidone-iodine dressing in non-healing ulcers

Background: The aim of the study was to evaluate effect of collagenase ointment and povidone-iodine on non-healing ulcer in the form of duration of ulcer covered with red granulation tissue and total hospital stay.Methods: The Study was conducted on 80 patients admitted in Surgery Department, SSG Hospital and Medical College Baroda, Gujarat, India during November 2006 to October 2008. All ulcers due to trauma, chronic ulcer or infected ulcer following debridement and incision and drainage were included in this study. In group A were wounds dressed in collagenase ointment and in group B were wounds dressed in povidone-iodine ointment till second surgery or complete healing. All data from both groups were collected and analyzed by chi-square test.Results: In this study, there was no difference in age distribution (p=0.62, p>0.05) with similar male to female ratio in both groups and also no significant difference in distribution of wounds size in both groups (p=0.92, p>0.05). Average size of wound in group A was 43 sq. cm and group B was 44 sq. cm. The significant difference was seen on floor of ulcer by healthy granulation which came on an average of within 11days in group A and within 18 days in group B (p=0.005, p<0.05). There was also a significant difference in average hospital stay, which was 25 days in group A and 35 days in group B (p=0.01, p<0.05).Conclusions:Collagenase ointment is clinically more efficient as a topical dressing and lowers the morbidity by reducing the hospital stay and the duration of dressing by promoting healing in non-healing wounds than povidine-iodine ointment.

Versatility of platelet rich fibrin in the management of alveolar osteitis—A clinical and prospective study.

ObjectiveTo assess the efficacy of Platelet Rich Fibrin (PRF) on the pain and healing of the extraction socket associated with Alveolar Osteitis (Dry Socket, AO) after removal of maxillary and mandibular molars. Study design100 adult patients with age group ranging from 18 to 40 years along with established dry socket after maxillary and mandibular molar extractions who have not received any treatment for the same were included in the study. PRF was placed in the maxillary and mandibular molar extraction sockets after adequate irrigation of the socket. All the patients evaluated for the various study variables which include pain, degree of inflammation, and healthy granulation tissue formation at 1st, 3rd, 7th, and 14th post operative day. Data were analyzed using Shapirowilk’s test, chi square test and/or student-t test, Friedman’s test, Wilcoxson’s signed rank test, and Bonferroni test, with the significance level set at P<0.05. ResultsThere was significant reduction in pain associated with AO at the 3rd and 7th postoperative day along with better wound healing by the end of 2nd week. ConclusionUse of PRF in this study illustrates the promising results in terms of reduced pain and better healing in the patients with Alveolar Osteitits.

Topical phenytoin dressing versus conventional dressing in diabetic ulcers

Background: Diabetic foot ulcer is estimated to affect 15% of all diabetic individuals during their lifetime. Management requires a multisystem approach. Various techniques have been tried to treat chronic ulcers, but none was proved to be ideal.Methods: This is a prospective randomised comparative study, where 56 patients with diabetic foot ulcers admitted in dept of surgery SSG hospital, Baroda, india were divided into two comparable groups. Of which 28 underwent topical phenytoin dressings, remaining 28 underwent Betadine dressing (5% w/v povidone – iodine solution). The variables were compared after 14 days based on rate of granulation tissue formation as percentage of ulcer surface area, wound culture-sensitivity and duration of hospital stay. Chi square test was used to compare the data at each of the assessment point in both groups. Results: In Phenytoin group, the mean rate of healthy granulation tissue formation was 60.71%, and mean hospital stay was 23.96 days with negative culture sensitivity was 54%. The Betadine group showed, the mean rate of granulation tissue formation was 11%, and mean hospital stay was 35 days with negative culture sensitivity was 18%.Conclusions: Topical phenytoin dressing considered as superior and cost effective in management of diabetic ulcers.

Efficiency of Enzymatic Debridement in the Healing Process of Chronic Wounds in Small Animal Practice

Abstract Skin wounds are a common presentation in small animal practice. These wounds may be acute or chronic with a complicated healing process. An important aspect of the healing of wounds is debridement which may be carried out by surgical, autolytic, mechanical or enzymatic methods. The debridement method is chosen according to the individual skin defect and influenced by factors such as wound size and location, the age of the wound, and the presence of infection or exudate. Enzymatic debridement is a method that is not commonly used in veterinary practice, and involves the use of enzyme preparations to remove necrotic tissue from a wound. The aim of this study was to investigate the effects of the enzymatic ointment collagenase as a method of debridement, and its effect on the macroscopic appearance of chronic skin wounds in cats and dogs. We observed that the application of Iruxol Mono directly to the wound changes the progress of the healing process, with no obvious adverse effects. The time of healing of chronic wounds was decreased and healthy granulation tissue was developed within a couple of days after application of the ointment. Enzymatic debridement appears to be a promising method of debridement for use in chronic wounds, and should be considered in cases where more conventional methods of debridement are ineffective or unsuitable.

A new low-cost negative-pressure wound therapy versus a commercially available therapy device widely used to treat complex traumatic injuries: a prospective, randomized, non-inferiority trial

OBJECTIVES:Negative-pressure wound therapy has been widely adopted to reduce the complexity of treating a broad range of acute and chronic wounds. However, its cost is high. The objective of this study was to evaluate the following two different methods of negative-pressure wound therapy in terms of healing time: a low-cost method of negative-pressure wound therapy (a pressure stabilizer device connected to a hospital wall-vacuum system with a gauze-sealed dressing, USP) and the standard of care (vacuum-assisted closure, VAC).METHODS:This is a randomized, controlled, non-inferiority, unblinded trial. Patients admitted with complex injuries to a trauma center in a public referral hospital who were indicated for orthopedic surgery were randomized to a USP or VAC group. The primary outcome was the time required to achieve a “ready for surgery condition”, which was defined as a wound bed with healthy granulation tissue and without necrosis or purulent secretion. Wound bed area contraction, granulation tissue growth and the direct costs of the dressings were secondary outcomes.RESULTS:Variation in area and granulation tissue growth were essentially the same between the systems, and healing time was equal between the groups (p=0.379). In both systems, serial debridement increased wound area (p=0.934), and granulation tissue was also increased (p=0.408). The mean treatment cost was US$ 15.15 in the USP group and US$ 872.59 in the VAC group.CONCLUSIONS:For treating complex traumatic injuries, USP was non-inferior to and less expensive than VAC.

Impact of nonscraping of granulation tissue on outcomes after skin grafting

Context: Chronic granulating burn wounds are covered with split-thickness skin grafts (SSG) after scraping of granulation tissue. But scraping is associated with increased blood and protein loss, and time required for hemostasis. We, therefore, conducted a study to determine if scraping can be avoided. Aims: Comparison of outcome of SSG and blood loss in burn wounds treated with and without scraping of granulation tissue. Settings and Design: Prospective clinical study. Materials and Methods: Over a year, 30 adult patients, with healthy granulating postburn wounds of size at least 100 cm2 and 4 to 10-week duration, were included. Wounds were divided into two halves, with one-half grafted after scraping (Group A) and other without scraping (Group B). Intraoperative blood loss was calculated. Dressings were done at postoperative days 3, 5, 7, and 10. Graft take, complete wound-healing time, and regrafting requirement were assessed. Statistical Analysis: Unpaired t test for quantitative variables. Results: Mean graft take (87.21 ± 9.48 Group A; 86.58 ± 11.18 Group B) was similar in both groups. Average intraoperative blood loss was significantly lesser (Group A 54.58 ± 6.5 mL/100 cm2; Group B 10.2 ± 1.5 mL/100 cm2), and duration of complete wound healing was increased without scraping (14.66 ± 2.79 days Group A; 15.73 ± 3.13 days Group B). There was no requirement of regrafting in both groups. Conclusion: Scraping of wound bed is avoidable in selected patients, although at expense of marginally faster healing. Leaving the healthy granulation tissue intact does not affect overall graft take and is associated with decreased blood loss.

Biodegradable polymer nanofiber membrane for the repair of cutaneous wounds in dogs - two case reports

The study of wound healing and its treatment is extremely important in veterinary medicine due to the high frequency of wounds and the difficulty in treating wounds by second intention. Thus, the objective of this study was to evaluate the use of a nanofiber membrane made of biodegradable polymers as a method of wound treatment in dogs. This study comprised two dogs with bite wounds. Debridement and cleaning was performed followed by the application of the membrane. In one dog, the wound was in the left proximal calcaneal region with clinical signs of infection, necrotic tissue, and muscle and the gastrocnemius tendon were exposed. The wound displayed rapid formation of granulation tissue which became excessive, so it was necessary to debride several times. However, with the suspension of the use of the membrane, formation of this tissue was not observed, and the wound evolved to epithelialization and fast contraction. In the second dog, there was a deep wound on the medial aspect of the proximal right hind limb, with clinical signs of infection, with muscle exposure. Once the membrane was placed, granulation tissue formed, and the membrane was used until the level of this tissue reached the skin. The wound underwent rapid epithelialization and contraction, without developing exuberant granulation tissue. Efficient wound repair was observed and the dogs exhibited greater comfort during application and use of the membrane. More studies should be conducted in dogs focusing on the application of this membrane until the appearance of healthy granulation tissue, as continued use seems to stimulate the formation of exuberant granulation tissue.

Vipareeta Malla Taila in the management of diabetic ulcer: A case report

Wound management is a common problem, encountered by medical practitioners all over the globe. The development and progression of a diabetic ulcer is made complex by a wide-range of diabetic complications. Without early and optimal intervention, the wound can rapidly deteriorate, leading to amputation of the affected limb. Vipareeta Malla Taila is an oil used in the management of chronic infected wounds mentioned in Ayurveda. A 46 year old Indian man presented with a boil over his left foot with a history of diabetes. After routine examination he underwent incision and drainage followed by daily dressing with gauze impregnated with Vipareeta Malla Taila for 28 days during which his wound healed completely. Sushruta (500BC) was the first to elaborately explain the management of wounds, wherein he explained the use of medicated oils in the management of chronic infected ulcers. Vipareeta Malla Taila helped in wound healing inspite of raised blood glucose levels throughout the treatment duration. Healing of a diabetic ulcer is a long process requiring constant vigil. With the application of Vipareeta Malla Taila, the wound responded by clearance of slough, promotion of healthy granulation and eventual epithelialization in a very short durationÂ

Regulation of Neuronal Survival by Nucleophosmin 1 (NPM1) Is Dependent on Its Expression Level, Subcellular Localization, and Oligomerization Status

NPM1 (nucleophosmin 1) is a nucleolar phosphoprotein that regulates many cellular processes, including ribosome biogenesis, proliferation, and genomic integrity. Although its role in proliferating cell types and tissues has been extensively investigated, little is known about its function in neurons and in the brain where it is highly expressed. We report that NPM1 protein expression is increased selectively in the striatum in both the R6/2 transgenic and 3-nitropropionic acid-injected mouse models of Huntington's disease. Examination of the effect of ectopic expression on cultured neurons revealed that increasing NPM1 is toxic to otherwise healthy cerebellar granule and cortical neurons. Toxicity is dependent on its cytoplasmic localization and oligomerization status. Forced retention of NPM1 in the nucleus, as well as inhibiting its ability to oligomerize, not only neutralizes NPM1 toxicity but also renders it protective against apoptosis. Although not blocked by pharmacological inhibition of the pro-apoptotic molecules, JNK, glycogen synthase kinase 3 beta, or caspases, toxicity is blocked by compounds targeting cyclin-dependent kinases (CDKs), as well as by dominant-negative forms of CDK1 and CDK2 and the pan-CDK inhibitor, p21(Cip1/Waf1) Although induced in in vivo Huntington's disease models, NPM1 protein levels are unchanged in cultured cerebellar granule and cortical neurons induced to die by low potassium or homocysteic acid treatment, respectively. Moreover, and counterintuitively, knockdown of its expression or inhibition of endogenous NPM1 oligomerization in these cultured neurons is toxic. Taken together, our study suggests that although neurons need NPM1 for survival, an increase in its expression beyond physiological levels and its translocation to the cytoplasm leads to death through abortive cell cycle induction.

External Beam Radiation Therapy of Squamous Cell Carcinoma in the Beak of an African Grey Parrot (Psittacus timneh)

Squamous cell carcinoma has been reported in a variety of bird species, most commonly psittacine and gallinaceous birds. The long-term prognosis in nongallinaceous birds is generally poor if complete surgical excision is not possible. Squamous cell carcinoma of the rhinotheca was diagnosed in a 34-year-old timneh African grey parrot (Psittacus timneh) with a 2-year history of beak abnormalities. No evidence of metastasis or local invasion were found on results of radiographs or computed tomography scan. The bird was treated with surgical debulking and palliative megavoltage radiation therapy. After 4 radiation treatments, the affected tissue was necrotic and was debrided to reveal healthy granulation tissue. The bird died approximately 7 months after diagnosis and 4 months after cessation of radiation treatment. At the time of death, a small scab lesion remained at the left oral commissure, but no visible tumor regrowth was evident. A postmortem examination was not performed, however, and tumor recurrence could not be ruled out in this bird.

The Efficacy and Safety of Tetrachlorodecaoxide in Comparison with Super-oxidised Solution in Wound Healing.

BackgroundSome of the relatively newer, more efficacious, and potent topical wound dressing solutions include tetrachlorodecaoxide and super-oxidised solution. This study compares the efficacy and safety of these two drugs.MethodsThis is a block-randomised, double blind, parallel-arm, post-marketing study. One hundred fifty patients with ulcers (75 blocks uniform for sex, ulcer aetiology, diabetes mellitus, and wound area score) were randomised into the two treatment arms. Patients were observed for eight weeks with weekly assessments. One hundred and twenty patients completed the study. Wound healing was objectively assessed by measurement of wound area, scoring of wound exudation and tissue type, and using the pressure ulcer scale of healing Tool (validated for multiple wound aetiologies). Subjective improvement in pain was noted using a visual analogue scale. Both groups were compared using Mann–Whitney U test on all indicators.ResultsDifference in change in wound tissue type in the two groups was significant (α=0.05) by intention-to-treat (ITT) and per-protocol (PP) analysis at the end of week two (ITT and PP, P<0.001) and week four (ITT, P=0.010; PP, P=0.009). P-values for other comparisons were not significant (P>0.05). No study-related adverse events were observed.ConclusionsBoth drugs are efficacious. Tetrachlorodecaoxide yields healthy granulation tissue earlier. Both drugs appear to be safe for application.

Evalution of the effectiveness of VAC-therapy in the preparatory stage of plastic wound closure in patients with diabetic foot

Purpose – to evaluate the efficiency of topical negative pressure wound therapy (NPWT) in comparison to standard therapy in post operative wounds in patients with diabetic foot syndrome.Materials and methods. The effects of negative pressure therapy on the clinical (size, tissue oxygenation), histological (light microscopy), morphometric and immunohistochemical (eNO synthase) aspects of repair of the soft tissue of the lower extremities in patients with diabetes mellitus in comparison with standard treatment. 60 patients with diabetic foot syndrome were included in the study from the moment of debridement till the plastic closure of the wound. During the perioperative period, 28 patients received NPWT (-50 to -120 mmHg) and 32 patients received standard therapy.Results and discussion. A reduction of the wound area by (24,6+12,2)% was achieved with negative pressure therapy compared with baseline data. In the control group, the corresponding values were (12,5+-11,4)%. The results of transcutaneous oximetry showed a greater increase in the level of local micro hemodynamics in the study group as compared to the control group (p &lt;0,05). An important criterion of wound preparation, for plastic closure of the wound is filling it with granulation tissue by more than 75%. 94% of the patients in the study group had (82,1% +-16)% of their wound filled with granulation tissue. The histological data of the study group showed a significant reduction of oedema by 80% (p &lt;0,05), improved extracellular matrix organization (p &lt;0,05), 90% (p &lt;0,05) dissolution of inflammatory infiltrate and the formation of healthy granulation tissue (p&lt;0,05). Immunohistochemical analysis demonstrated a significant increase in the number of fibroblasts in the dermis (p &lt;0,05), increased expression of eNO synthase.Conclusions. The findings suggest that negative pressure therapy (-50 to -120 mmHg) is more efficient compared with standard treatment and achieves more rapid reduction of the area and depth of the wound, increased local microcirculation and decreased inflammation. These findings were confirmed histologically and immunohistochemically. The high efficiency of this method significantly reduced the time required for preparing the wound for autodermoplasty.

Amniotic membrane can be a valid source for wound healing.

Amniotic membrane (AM) can promote proper epithelialization with suppression of excessive fibrosis by creating a supportive milieu for regeneration of chronic ulcer bed.ObjectiveThe objective of this study is to investigate whether AM scaffold can modulate the healing of a wound by promoting tissue reconstruction rather than promoting scar tissue formation.Subjects and methodsAM was obtained and prepared and then applied to patients with chronic leg ulcers who were randomly divided into two different groups. Group I (control group) included eleven patients in whom ulcers were treated with conventional wound dressings that were changed daily for 8 weeks. Group II (study group) included 14 patients in whom the AM was placed in contact with the ulcer and held in place with a secondary dressing, which was changed daily. Follow-up was done to detect healing rate and detection of ulcer size, assessment of pain, and to take ulcer images (days 0, 7, 14, 21, 30, 45, and 60).ResultsIn group I, all ulcers showed no reduction in their size, and ulcer floor remained the same. Healthy granulations were present in two ulcers (18.2%) and absent in nine ulcers (81.8%). There was no improvement of pain level in the eleven ulcers. In group II, complete healing of 14 ulcers occurred in 14–60 days with a mean of 33.3±14.7; healing rate range was 0.064–2.22 and the mean 0.896±0.646 cm2/day. Healthy granulations were present in 13 ulcers (92.9%) and absent in one ulcer (7.1%). Three ulcers (21.4%) were of mild severity (grade 1 ulcers) while eleven ulcers (78.6%) were of moderate severity (grade 2 ulcers). The healing rate was faster in ulcers of mild severity (1.7±0.438 cm2/day) in comparison to ulcers of moderate severity (0.673±0.498 cm2/day). Eleven cases (78.6%) showed improvement in their pain level on a scale from 0 to 10.ConclusionAM graft can be of value in wound healing. Further studies are needed to confirm these findings.

The advances of unhealthy granulation tissue care

Healthy granulation tissue played an important role in the wound healing process. However, some factors which interfered the process would result in unhealthy granulation tissue. Unhealthy granulation tissue may affect wound repairing. This article would focus on the concept, mechanisms, interventions of unhealthy granulation tissue. Key words: Nursing care; Wound bed; Unhealthy granulation tissues

Temporary Relocation of the Testes in Anteromedial Thigh Pouches Facilitates Delayed Primary Scrotal Wound Closure in Fournier Gangrene With Extensive Loss of Scrotal Skin-Experience With 12 Cases.

To share our experience on the use of temporary testicular thigh pouches to facilitate scrotal wound closure in Fournier gangrene with extensive loss of scrotal skin. Patients seen over a 10-year period who had extensive (>50%) loss of scrotal skin precluding delayed primary closure of the residual scrotal skin over the testes were documented. Patients had serial debridement as required with scrotal wound dressing until healthy granulation tissue was achieved. The testes were placed temporarily in anteromedial thigh pouches to allow for scrotal wound closure. In the postoperative period, the testes were gradually massaged back into the residual scrotal pouch, thus acting as natural tissue expanders. Mean patient age was 38.1 ± 10.0 years. Mean duration of admission was 24.4 ± 4.7 days. Identified predisposing factors were ischiorectal fossa abscess in 2 patients and urethral stricture in 1 patient. The rest were idiopathic. Mean Fournier gangrene severity index was 6.0 ± 1.3. Mean number of debridements was 2.3 ± 0.5. There was no mortality. The residual scrotal pouches expanded sufficiently over time (3-8 months) to accommodate the testes. Normal testicular volume was maintained in all patients. Mean testicular volume was 19.0 ± 3.2 cm. Follow-up was for 14.8 ± 9.7 months. Temporarily relocating the testes in anteromedial thigh pouches facilitates scrotal wound closure in Fournier gangrene with extensive loss of scrotal skin and obviates the need for specialized reconstructive surgery.

Papaya pulp for enzymatic wound debridement in burns

Context: Early surgical debridement in burns has its disadvantages like extensive blood loss and long anaesthesia time and risks. Enzymatic wound debridement as an alternative to surgical debridement has been assessed for its effectiveness, safety and patient compliance. Aims: To assess the effectiveness and safety of papaya pulp as an enzymatic wound debriding agent in burns. Setting and Design: The study was conducted including 50 patients with second degree and third degree burns, age ranging from 15 to 60 years from January 2004 to December 2004 at the Burns Centre, Department of Plastic, Reconstructive and Burns Surgery, Jubilee Mission Medical College and Research Institute, Thrissur, Kerala, India. Materials and Methods: A prospective study including 50 patients with second degree and third degree burns, age ranging from 15 to 60 years was carried out from January 2004 to December 2004 at the Burns Centre, Department of Plastic, Reconstructive and Burns Surgery, Jubilee Mission Medical College and Research Institute, Thrissur, Kerala, India. There were 38 female and 12 male patients in the study group. Areas of burns ranging from 10% to 60% TBSA were included in the study. Daily dressings were done using autoclaved unripe papaya pulp smeared on potato peel dressing. The progress was assessed daily and application stopped when adequate debridement has been achieved or a maximum of 1 week. Statistical Analysis Used: None. Results: All 50 patients included initially completed the study. There were 38 females and 12 males. Papaya pulp was found to be a very effective debriding agent in all cases. Deep dermal wounds cleared up in 5 to 6 days and eschar in full thickness burns became loose by this period so that it needed minimal surgical debridement. The granulation tissue found following debridement with papaya pulp was pink and healthy. In patients who had to be taken up for grafting, a mild scraping was sufficient before placement of a graft. This has helped on reducing blood transfusions and has considerably reduced anaesthesia time. Conclusions: The use of papaya pulp results in 1. Early and complete non-invasive debridement, 2. Healthy granulation tissue, 3. Decreased blood loss and hence decreased number of blood transfusions in cases which have to be grafted, as excision is avoided. 4. Less operating time and hence less anaesthesia time.

Efficacy of a Single Dose of Basic Fibroblast Growth Factor: Clinical Observation for 1 Year

Basic fibroblast growth factor promotes wound healing by accelerating healthy granulation and epithelialization. However, the duration of the effects of a single intracordal injection of basic fibroblast growth factor has not been established, and administration intervals and timing have yet to be standardized. Here, we administered a single injection to patients with insufficient glottic closure and conducted follow-up examinations with high-speed digital imaging to determine the duration of the treatment response. Case series. For treatment, 20 µg/mL recombinant human basic fibroblast growth factor was injected into two vocal cords. The following examinations were performed before the procedure and at 3-month intervals for 12 months starting at 1 month postinjection: Grade, Roughness, Breathiness, Asthenia, and Strain (GRBAS) scale assessment, maximum phonation time, acoustic analysis, high-speed digital imaging, glottal wave analysis, and kymographic analysis. Postinjection, the GRBAS scale score decreased, and the maximum phonation time was prolonged. In addition, the mean minimum glottal area and mean minimum glottal distance decreased. These changes were significant at 12 months postinjection compared with preinjection. However, there were no significant changes in the vibrations of the vocal cord margins. The intracordal injection of basic fibroblast growth factor improved insufficient glottic closure without reducing the vibrations of the vocal cord margins. This effect remained evident at 12 months postinjection. A single injection can be expected to yield a sufficient and persistent long-term effect.

Simultaneous Reconstruction of Forefoot and Hindfoot Defects with a Thoracodorsal-Axis Chimeric Flap.

Simultaneous Reconstruction of Forefoot and Hindfoot Defects with a Thoracodorsal-Axis Chimeric Flap.

Ephrin-Bs Drive Junctional Downregulation and Actin Stress Fiber Disassembly to Enable Wound Re-epithelialization.

SummaryFor a skin wound to successfully heal, the cut epidermal-edge cells have to migrate forward at the interface between scab and healthy granulation tissue. Much is known about how lead-edge cells migrate, but very little is known about the mechanisms that enable active participation by cells further back. Here we show that ephrin-B1 and its receptor EphB2 are both upregulated in vivo, just for the duration of repair, in the first 70 or so rows of epidermal cells, and this signal leads to downregulation of the molecular components of adherens and tight (but not desmosomal) junctions, leading to loosening between neighbors and enabling shuffle room among epidermal cells. Additionally, this signaling leads to the shutdown of actomyosin stress fibers in these same epidermal cells, which may act to release tension within the wound monolayer. If this signaling axis is perturbed, then disrupted healing is a consequence in mouse and man.