Premenopausal women deposit more collagen than men during healing of an experimental wound

Chronic intermittent hypoxia modulates corneal fibrotic markers and inflammatory cytokine expression in a sex-dependent manner

Chronic intermittent hypoxia (CIH) is a commonly observed condition in patients suffering from obstructive sleep apnea (OSA). Previous studies link CIH to fibrosis, inflammation, and hormonal dysregulation across various tissues. Yet, the effect of CIH in the cornea is unknown. Moreover, women and men diagnosed with OSA present with diverse symptoms, suggesting sex-specific pathophysiology at play. Thus, we used a rat model to assess the impact of CIH and sex on protein expression of corneal fibrotic markers (α-SMA, COL III, cFN, TSP-1), proinflammatory cytokines (IL-1 α, IL-17, IL-18, and IFN-γ), and hormone receptors (ERα, ERβ, GPER, GnRH-R, and LH-R). Male and female Sprague Dawley rats were exposed to normoxic or CIH conditions during their sleep cycle for 14 days. Extracted corneal proteins were subjected to Western blot and multiplex magnetic bead analysis. Our results reveal sex differences in fibrotic and inflammatory markers in the cornea, whereby female corneas exhibit higher levels of fibrotic markers, while male corneas exhibit increased inflammatory cytokines. CIH exposure resulted in elevated levels of α-SMA and pro-inflammatory cytokines in female corneas, while there was no impact on fibrotic or inflammatory markers in male corneas. Additionally, CIH exposure reduced hormone receptors in male and female corneas in a sex-dependent manner. Correlation analyses identified associations of corneal hormone receptors with corneal fibrotic and pro-inflammatory markers that were dependent on sex, with female corneas demonstrating stronger correlations compared to male corneas. Altogether, our data suggests hormone-mediated signaling may contribute to CIH-mediated corneal fibrosis and inflammatory phenotypes, especially in females.

GPER deficiency impedes murine myocutaneous revascularization and wound healing

Estrogens regulate numerous physiological and pathological processes, including wide-ranging effects in wound healing. The effects of estrogens are mediated through multiple estrogen receptors (ERs), including the classical nuclear ERs (ERα and ER β ), that typically regulate gene expression, and the 7-transmembrane G protein-coupled estrogen receptor (GPER), that predominantly mediates rapid "non-genomic" signaling. Estrogen modulates the expression of various genes involved in epidermal function and regeneration, inflammation, matrix production, and protease inhibition, all critical to wound healing. Our previous work demonstrated improved myocutaneous wound healing in female mice compared to male mice. In the current study, we employed male and female GPER knockout mice to investigate the role of this estrogen receptor in wound revascularization and tissue viability. Using a murine myocutaneous flap model of graded ischemia, we measured real-time flap perfusion via laser speckle perfusion imaging. We conducted histologic and immunohistochemical analyses to assess skin and muscle viability, microvascular density and vessel morphology. Our results demonstrate that GPER is crucial in wound healing, mediating effects that are both dependent and independent of sex. Lack of GPER expression is associated with increased skin necrosis, reduced flap perfusion and altered vessel morphology. These findings contribute to understanding GPER signaling in wound healing and suggest possible therapeutic opportunities by targeting GPER.

Hernia Formation: Risk Factors and Biology

The incidence of ventral hernias in the United States is in increasing. Herein, the author details the etiology of congenital and acquired ventral hernias as well as the risk factors associated with the development of each of these types of ventral hernias.

Evaluation of healing outcomes combining a novel polymer formulation with autologous skin cell suspension to treat deep partial and full thickness wounds in a porcine model: a pilot study

Autologous skin cell suspensions (ASCS) can treat burns of varying depths with the advantage of reduced donor site wound burden. The current standard primary dressing for ASCS is a nonabsorbant, non-adherent, perforated film (control) which has limited conformability over heterogeneous wound beds and allows for run-off of the ASCS. To address these concerns, a novel spray-on polymer formulation was tested as a potential primary dressing in porcine deep partial thickness (DPT) and full thickness (FT) wounds. It was hypothesized that the polymer would perform as well as control dressing when evaluating wound healing and scarring. DPT or FT wounds were treated with either a spray-on poly(lactic-co-glycolic acid) (PLGA) and poly(lactide-co-caprolactone) (PLCL) formulation or control ASCS dressings. Throughout the experimental time course (to day 50), we found no significant differences between polymer and control wounds in % re-epithelialization, graft-loss, epidermal or dermal thickness, or % dermal cellularity in either model. Pigmentation, erythema, elasticity, and trans-epidermal water loss (TEWL), were not significantly altered between the treatment groups, but differences between healing wounds/scars and un-injured skin were observed. No cytotoxic effect was observed in ASCS incubated with the PLGA and PLCL polymers. These data suggest that the novel spray-on polymer is a viable option as a primary dressing, with improved ease of application and conformation to irregular wounds. Polymer formulation and application technique should be a subject of future research.

The effect of expressive writing on wound healing: Immunohistochemistry analysis of skin tissue two weeks after punch biopsy wounding

OBJECTIVE

To investigate the effects of expressive writing and its timing (pre or post wounding) on re-epithelialisation and leucocyte subsets within healing tissue. We previously showed expressive writing pre-wounding improved re-epithelialisation. Here we investigate cellular processes in the wound.

METHODS

In a 2(writing content) x 2(writing timing) randomized trial, 122 participants were randomized to perform either expressive or control writing, before or after a 4 mm punch biopsy wound. On day 14 post-wounding, participants had a 5 mm punch biopsy of the initial wound. Seven of 16 primary registered outcomes were analysed, including re-epithelialisation from two photographs of the 4 mm biopsy (previously reported). This paper reports immunohistochemistry analysis of five primary outcomes - Langerhans cells, immune cell activation (HLA and CD3+), and macrophages (CD68 and MPO) - in the 5 mm biopsies in a random sample of 96 participants.

RESULTS

Participants who performed either writing task pre-wounding had greater Langerhans cell infiltration, than those who wrote post-wounding (F_(1,85) = 7.86, p = .006, η_p² = 0.08). Those who performed expressive writing also had greater Langerhans cell infiltration than those who performed control writing (F_(1,85) = 4.00, p = .049, η_p² = 0.04). There were no significant group or interaction effects on immune cell activation or macrophages. Healed wounds on day 10 had lower levels of macrophages (z = -1.96, p = .050), and CD3+ cells (z = -1.99, p = .046) than non-healed wounds.

CONCLUSION

Langerhans cells in the healing skin are affected by the timing and topic of writing. More research is needed to further explore timing and corroborate these results.

CLINICAL TRIALS REGISTRATION

Registered at https://www.anzctr.org.au/ (Trial ID: ACTRN12614000971639).

The Impact of Corticosteroid Administration at Different Time Points on Mucosal Wound Healing in Rats: An Experimental Pilot In Vivo Study

Simple Summary

The objective of this pilot study was to evaluate the impact of corticosteroid (CS) administration at different time points on palatal wound healing in rats. Thirty-six young male rats were divided into three groups. The test groups were treated by CS in the early (1–4 days) and late (5–9 days) stages after palatal wounding, while the control group was left for spontaneous healing. Our findings do not support the positive impact of CS administration on palatal wound healing. While microscopically, we found no difference between the CS and control groups, CS exposure was associated with a macroscopically larger final wound area, reflecting a possible harmful effect of CS.

Abstract

Background: Conflicting results were found regarding the effect of corticosteroid (CS) administration upon wound healing. The objective of this pilot study was to evaluate the impact of CS administration at different time points on palatal wound healing in rats. Methods: A 4.2 mm diameter punch created a secondary healing excisional palatal defect in thirty-six (36) Wistar-derived, two-month-old male rats weighing 250–270 g. We evaluated the effect of CS by comparing wound healing between three equal groups: 12 rats who were not exposed to CS and two additional groups in which 1 mg/kg dexamethasone (1 mg/kg) was administered daily, early (1–4 days) and late (5–9 days) after injury. The dynamics of the healing process were evaluated weekly in 4 sacrificed rats from each group for three weeks. The wound area was assessed both macroscopically and microscopically; the inflammation score was assessed microscopically. Results: The initial wound area in all the rats was 13.85 mm². At the end of the study, it decreased to 4.11 ± 0.88 mm², 7.32 ± 2.11 mm², and 8.87 ± 3.01 mm² in control, early, and late CS administration groups, respectively (p = 0.075). Inflammation scores showed a tendency to decrease in the third week in all groups, with no statistical differences. Conclusions: Our findings do not support the positive impact of CS administration on palatal wound healing. While microscopically, we found no difference between the CS and control groups, CS exposure was associated with a macroscopically larger final wound area, reflecting a possible harmful effect of CS.

Männer- und Frauenhaut – Genderaspekte

Männer- und Frauenhaut sind unterschiedlich. Männerhaut ist dicker, hat mehr Talgdrüsen und Oberflächenlipide, eine höhere, nicht so divergente Keimzahl wie Frauen, niedrigere transepidermale Wasserverlust (TEWL)-Werte und einen niedrigeren pH-Wert. Die Wundheilung und das Niveau von Antioxidantien ist bei Frauenhaut besser. Männerhaut hat mehr Kollagen, altert an anderer Lokalisation, bei Männern finden sich mehr Falten an der Stirn, bei Frauen mehr Falten perioral. Studien sollten die Auswertung der Daten nach Geschlechtern mit beachten.

Sex Hormones, Growth Hormone, and the Cornea

The growth and maintenance of nearly every tissue in the body is influenced by systemic hormones during embryonic development through puberty and into adulthood. Of the ~130 different hormones expressed in the human body, steroid hormones and peptide hormones are highly abundant in circulation and are known to regulate anabolic processes and wound healing in a tissue-dependent manner. Of interest, differential levels of sex hormones have been associated with ocular pathologies, including dry eye disease and keratoconus. In this review, we discuss key studies that have revealed a role for androgens and estrogens in the cornea with focus on ocular surface homeostasis, wound healing, and stromal thickness. We also review studies of human growth hormone and insulin growth factor-1 in influencing ocular growth and epithelial regeneration. While it is unclear if endogenous hormones contribute to differential corneal wound healing in common animal models, the abundance of evidence suggests that systemic hormone levels, as a function of age, should be considered as an experimental variable in studies of corneal health and disease.

Is sex a biological variable in corneal wound healing?

Wound healing differs significantly between men and women in a tissue-dependent manner. Dermal wounds heal faster in women whereas mucosal wounds heal faster in men. However, the effect of sex as a variable in corneal wound healing is largely unknown. The primary objective of this study was to test whether sex is a biological variable in corneal wound healing activated by the trauma or injury using an established in vivo rabbit model with male and female New Zealand White rabbits. Corneal wounds in rabbits were produced by a single topical alkali (0.5N Sodium hydroxide) application. Serial slit-lamp, stereo biomicroscopy, and applanation tonometry evaluated corneal opacity, anterior segment ocular health, and intraocular pressure (IOP), respectively, at various times during the study. Fourteen days after alkali-wound, corneal tissues were collected after humane euthanasia to examine cellular and molecular wound healing parameters. Quantitative PCR (qPCR) and immunofluorescence were used to quantify changes in the extracellular modeling protein levels of alpha-smooth muscle actin (α-SMA), Fibronectin (FN), Collagen-I (Col-I), and Transforming growth factor beta 1 (TGFβ1) involved in corneal healing. Hematoxylin and Eosin (H&E) staining was used to study histopathological changes in morphology and TUNEL assay to evaluate levels of apoptotic cell death. Male and female rabbits showed no significant differences in corneal opacity (Fantes score) or intraocular pressure (IOP) values (9.5 ± 0.5 mm Hg) in live animals. Likewise, no statistically significant sex-based differences in the mRNA levels of α-SMA (male = 5.95 ± 0.21 fold vs. female = 5.32 ± 0.043), FN (male = 3.02 ± 0.24 fold vs. female = 3.23 ± 0.27), Col-I (male = 3.12 ± 0.37 fold vs. female = 3.31 ± 0.24), TGFβ1 (male = 1.65 ± 0.06 fold vs. female = 1.59 ± 0.053); and protein levels of α-SMA (male = 74.16 ± 4.6 vs. female = 71.58 ± 7.1), FN (male = 60.11 ± 4.6 vs. female = 57.41 ± 8.3), Col-I (male = 84.11 ± 2.8 vs. female = 84.55 ± 3.6), TGFβ1 (male = 11.61 ± 2.8 vs. female = 9.5 ± 3.04) were observed. Furthermore, H&E and TUNEL analyses found no statistically significant differences in cellular structures and apoptosis, respectively, in male vs. female corneas. Consistent with earlier reports, wounded corneas showed significantly increased levels of these parameters compared to the unwounded corneas. Our data suggest that sex is not a major biological variable during active early stages of corneal wound healing in rabbits in vivo.

Temporal progression of gene regulation of peripheral white blood cells explains gender dimorphism of critically ill patients after trauma

BACKGROUND

The immune response of the critically ill after severe trauma is sex-specific and may explain the different progression of the disease. This may be explained by a different gene regulatory program of their peripheral immune cells. We investigated the progression of the transcription profiles of peripheral immune cells of the patients to elucidate their distinct physiological response and clinical course.

METHODS

We compared transcription profiles of whole blood of male and female patients from a larger longitudinal study of critically ill patients after trauma. We developed a statistical analysis pipeline that synchronized the time lapse of the profiles based on the temporal severity score of each patient.

RESULTS

This enabled to categorize the temporal progression of the disease into two pre-acute, an acute and two post-acute phases. Comparing gene regulation of male and female patients at each phase, we identified distinctively regulated molecular processes mainly in the immune response, but also in the regulation of metabolism allowing to cluster these discriminative gene sets into sets of highly related cellular processes. Compared to male patients and healthy controls, female patients showed upregulation of gene sets of innate immunity in the early phase, upregulation of wound healing processes during the acute phase and upregulation of adaptive immunity in the late phase indicating early recovery. In turn, during the pre-acute and acute phase, male patients showed less suppression of gene sets coding for enzymes of energy metabolism and anabolism, most prominently the tricarboxylic acid cycle and β-oxidation, and cellular maintenance, such as cell cycle, DNA replication and damage response, and RNA metabolism.

CONCLUSIONS

A stronger innate immune response at the very early phase of the disease may support early clearance of the pathogen and its associated molecular patterns. Upregulation of wound healing processes may explain reduced multiple organ failure during the acute phase. Down regulated energy metabolism during the acute phase may make female patients less susceptible to oxidative stress, the upregulated adaptive immune system reflects an earlier recovery and rebuilding of the adaptive immune system that may protect them from secondary infections. Follow up studies need to be performed confirming these observations experimentally.

The effect of gender on early colonic anastomotic wound healing

PURPOSE

Clinically, male patients subjected to colorectal surgery are more prone to develop anastomotic leakage than female patients by unknown mechanisms. Our aim was to investigate the impact of gender on anastomotic wound healing using an experimental model.

METHODS

One-layer colonic anastomosis was constructed in 8-week-old 28 male and 32 female Sprague-Dawley rats. Animals of one group (n = 30) were sacrificed immediately after surgery day 0 and the other group (n = 30) on postoperative day 3. Anastomotic breaking strength, total collagen (hydroxyproline), soluble collagen (Sircol), matrix metalloproteinase (MMP)-9, and transforming growth factor (TGF)-β1 were measured.

RESULTS

The anastomotic breaking strength decreased from day 0 to day 3 with no significant gender differences either in the extent of decline (P = 0.122) or absolute day 3 strengths (P = 0.425). Analogously, total collagen concentration in the anastomotic wounds decreased postoperatively and were lower (P = 0.043) in the male compared with the female rats on day 3. MMP-9 levels increased in the anastomoses postoperatively, but they did not differ (P = 0.391) between male and female animals. Soluble collagen levels were lower in the day-3 anastomoses of male versus female rats (P = 0.015) and correlated positively with total TGF-β1 levels (r_S = 0.540, P = 0.006). Although TGF-β1 tended to be lower in male compared with the female rats, the differences did not reach statistical significance.

CONCLUSION

Our findings point towards a less favorable collagen metabolism in colonic anastomoses of male compared with female rats during early wound healing.

Androgen actions in mouse wound healing: Minimal in vivo effects of local antiandrogen delivery

The aims of this work were to define the role of androgens in female wound healing and to develop and characterize a novel wound dressing with antiandrogens. Androgens retard wound healing in males, but their role in female wound healing has not been established. To understand androgen receptor (AR)-mediated androgen actions in male and female wound healing, we utilized the global AR knockout (ARKO) mouse model, with a mutated AR deleting the second zinc finger to disrupt DNA binding and transcriptional activation. AR inactivation enhanced wound healing rate in males by increasing re-epithelialization and collagen deposition even when wound contraction was eliminated. Cell proliferation and migration in ARKO male fibroblasts was significantly increased compared with wild-type (WT) fibroblasts. However, ARKO females showed a similar healing rate compared to WT females. To exploit local antiandrogen effects in wound healing, while minimizing off-target systemic effects, we developed a novel electrospun polycaprolactone (PCL) scaffold wound dressing material for sustained local antiandrogen delivery. Using the antiandrogen hydroxyl flutamide (HF) at 1, 5, and 10 mg/mL in PCL scaffolds, controlled HF delivery over 21 days significantly enhanced in vitro cell proliferation of human dermal fibroblasts and human keratinocytes. HF-PCL scaffolds also promoted in vivo wound healing in mice compared with open wounds but not to PCL scaffolds.

Proxy measures of vitamin D status - season and latitude - correlate with adverse outcomes after bariatric surgery in the Nationwide Inpatient Sample, 2001-2010: a retrospective cohort study

Objective

To investigate the association between adverse surgical outcomes following bariatric surgery and proxy measures of vitamin D (VitD) status (season and latitude) in the Nationwide Inpatient Sample (NIS).

Background

Obesity is an independent risk factor for VitD deficiency (25(OH)D < 20 ng ml⁻¹). VitD deficiency compounds the chronic inflammation of obesity, increasing the risk of adverse outcomes following bariatric surgery. Epidemiology has long used season and latitude as proxies for group VitD, as VitD status is largely determined by sun exposure, which is greatest during summer and at the Equator.

Methods

We assessed proxy measures of group VitD status. We compared surgeries in VitD Summer (July to September), Winter (January to March), and Fall/Spring (October to December and April to June) and in the North (≥37°N) vs. the South (<37°N).

Results

We identified 932,091 bariatric surgeries; 81.2% were women and 74.4% were white. Sex was unequally distributed by season (p = 0.005). Median age was 43.0 years (all groups). Most surgeries occurred in the North (64.8%). Adverse outcome rates ranged from 0.01% (wound infections) to 39.4% [prolonged length of stay {LOS}]. Season was inversely associated with wound infection (p = 0.018) and dehiscence (p = 0.001). Extended LOS was inversely correlated with season (p < 0.001). These relationships held after adjustment. Prolonged LOS (p < 0.001) and any complication (p = 0.108) were more common in the North.

Conclusions

We have demonstrated a graded relationship between seasonality and adverse outcomes following bariatric surgery. The association was strongest for dehiscence and prolonged LOS. These relationships held when using latitude. A prospective study measuring pre‐operative 25(OH)D concentration would strengthen the case for causality in adverse surgical outcomes.

A Clinical Parameters-Based Model Predicts Anastomotic Leakage After a Laparoscopic Total Mesorectal Excision: A Large Study With Data From China

Anastomotic leakage after colorectal surgery is a major and life-threatening complication that occurs more frequently than expected. Intraoperative judgment in predicting potential leakage has shown extremely low sensitivity and specificity. The lack of a model for predicting anastomotic leakage might explain this insufficient judgment. We aimed to propose a clinical parameters-based model to predict anastomotic leakage after laparoscopic total mesorectal excision (TME).This study was a retrospective analysis of a prospectively designed colorectal cancer dataset. In total, 1968 patients with a laparoscopic TME were enrolled from November 1, 2010, to March 20, 2014. The independent risk factors for anastomotic leakage were identified, from which the parameters-based model for leakage was developed.Anastomotic leakage was noted in 63 patients (3.2%). Male sex, a low level of anastomosis, intraoperative blood loss, diabetes, the duration time of the surgery, and low temperature were significantly associated by the bivariate analysis and the Cochran-Mantel-Haenszel test with an increased risk. From these factors, the logistic regression model identified the following 4 independent predictors: male sex (risk ratio [RR] = 1.85, 95% confidence interval [CI]: 1.13-4.87), diabetes (RR = 2.08, 95% CI: 1.19-5.8), a lower anastomosis level (RR = 3.41, 95% CI: 1.17-6.71), and a high volume of blood loss (RR = 1.03, 95% CI: 1.01-1.05). The locally weighted scatterplot smoothing regression showed an anastomosis within 5 cm from the anus and intraoperative blood loss of >100 mL as the cutoff values for a significantly increased risk of leakage. Based on these independent factors, a parameters-based model was established by the regression coefficients. The high and low-risk groups were classified according to scores of 3-5 and 0-2, with leakage rates of 8.57% and 1.66%, respectively (P < 0.001).This parameters-based model could predict the risk of anastomotic leakage following laparoscopic rectal cancer. After further validation, this model might facilitate the intraoperative recognition of high-risk patients to perform defunctional stomas.

SERI Surgical Scaffold as an Adjunct for Circumferential Abdominoplasty and Lower Body Lift

Summary:

Patients who have undergone massive weight loss typically have poor-quality skin and fascia and thus are prone to experiencing recurrent skin laxity, bulges, and poor scarring after body contouring efforts, even in the hands of experienced surgeons. Moreover, this challenging patient population often has nutritional deficiencies and concomitant medical problems, which may lead to delayed or suboptimal wound healing. A silk-derived biological scaffold (SBS) and its facilitation of autogenous tissue generation may be viewed as a qualitative reinforcement of the superficial fascial system. Therefore, it may help support and stabilize a superficial fascial system that has been weakened by obesity and other factors. When employed in body lifting for patients with massive weight loss who desire long-lasting aesthetic results, it may represent a paradigm shift that has the potential to solve at least some issues that plague this patient population. In the present case of circumferential abdominoplasty and lower body lift, this silk-based bioresorbable scaffold was implanted in one side of the patient’s body but not the other. Throughout the 7-month follow-up period, the patient and her husband (who were blinded as to which side received the SBS) and the author consistently observed more favorable results for the SBS side, which included greater postoperative comfort, better shape, higher buttock position, less recurrent laxity, and less descent of the scar.

Wound healing process in post-bariatric patients: an experimental evaluation

Bariatric surgery is the most effective treatment for morbid obesity. Despite this, side effects are recorded. One of them is redundant skin hanging from the patients' body causing both aesthetical and functional deformities. They can only be corrected with body contouring surgery, whose wound complication rate is very high in previously obese population. Despite several hypotheses, an adequate explanation is still awaited. The aim of our study was to evaluate the wound healing process in post-bariatric patients. Seven patients, six women and one man, were enrolled. They all were nonsmokers and nondiabetic. They all underwent biliopancreatic diversion (BPD). After 36 months, abdominoplasty was performed. Biochemical parameters before and after bariatric surgery were evaluated. The content of total protein and hydroxyproline was assessed in multiple scar biopsies before and after BPD. Abdominoplasty horizontal scar skin samples were subjected to histological evaluation with Weigert-Van Gieson stain for elastic fibers and connectivum. All biochemical parameters analyzed were reduced post-BPD compared to the preoperative period. Tissue proteins were significantly reduced after BPD both in their totality and as hydroxyproline and hydroxyproline/total tissue protein. Histological evaluation revealed abnormal dermal elastic and collagen fibers. The cause of aberrant healing in massive weight loss body contouring is likely multifactorial. A relationship between nutritional state, wound collagen accumulation, and elastic fiber content seems to be only partially involved. The high mechanical stress of tissues before BPD probably influences the wound healing process after BPD.

Connective tissue alteration in abdominal wall hernia

BACKGROUND

The aetiology and pathogenesis of abdominal wall hernia formation is complex. Optimal treatment of hernias depends on a full understanding of the pathophysiological mechanisms involved in their formation. The aim of this study was to review the literature on specific collagen alterations in abdominal wall hernia formation.

METHODS

A computer-assisted search of the medical databases PubMed and Embase was performed, together with a cross-reference search of eligible papers.

RESULTS

Fifty-two papers were included. Collagen alteration depended on the type of hernia; there were more pronounced changes in patients with a direct inguinal hernia than in those with an indirect inguinal hernia, recurrent inguinal hernia or incisional hernia. A consistent finding was a significant increase in immature type III collagen relative to the stronger type I collagen in patients with a hernia. This resulted in thinner collagen fibres with a correspondingly diminished biomechanical strength. It has been suggested that these alterations are due to variation in the synthesis, maturation or degradation of collagen by matrix metalloproteinases, in combination or alone.

CONCLUSION

Hernia formation and recurrence is associated with altered collagen metabolism manifested by a decreased type I:III collagen ratio.

Biomechanical properties of skin in massive weight loss patients

BACKGROUND

The aim of this study is to assess skin strength in MWL patients relative to control cosmetic abdominoplasty patients biophysically, biochemically, and histologically. Growing success of weight loss programs has brought about an increase in the MWL population. Skin quality is thought to be impaired by MWL, but there are no compelling studies that have fully addressed the structural mechanisms involved.

METHODS

Skin from the medial and lateral abdomen was harvested fresh from patients undergoing cosmetic abdominoplasty (n = 6) or abdominal panniculectomy for MWL (n = 35), and burst strength was tested in the horizontal and vertical directions. Collagen content was measured, and histological studies were performed to assess epidermal and dermal thickness, vascularity as well as the morphology and density of the collagen fibers.

RESULTS

In all groups, skin stretched horizontally was stronger than skin stretched vertically (p < 0.001). The skin of MWL patients was stronger medially compared to the skin of cosmetic patients. (p = 0.047) Newly formed collagen was diminished in MWL than that in the control group, but the results were not statistically significant. Epidermal thickness was significantly higher medially in MWL (p = 0.049). Elastin fibers were decreased in the MWL group, while dermal vascularity was higher in the MWL group.

CONCLUSIONS

The skin of MWL patients demonstrated stronger mechanical parameters than that of cosmetic patients in the medial part of the abdomen; however, the decrease in elastic fibers associated with a decrease in newly formed collagen seemingly provides a contradiction. Skin changes with MWL merits further study to understand it more completely.

Wound complications in thyroxine-supplemented patients following foot and ankle surgery

BACKGROUND

Our hypothesis was that thyroxine supplementation in patients undergoing foot and ankle surgery would be associated with increased postoperative wound complications and wound dehiscence compared to patients without thyroxine supplementation.

MATERIALS AND METHODS

A retrospective review of 48 patients supplemented with thyroxine that underwent foot and ankle surgery was conducted and analyzed for wound complications. All patients were non-diabetic. A total of 94 historical controls were used to compare the incidence of wound complications to the thyroxine sample. Patient demographics, medical comorbidities, principal diagnosis and procedure performed were recorded. The presence or absence of wound dehiscence, infection or other wound complications was recorded for all patients based on the followup clinical notes in the electronic record.

RESULTS

In the thyroxine group, the most common diagnosis was degenerative arthritis (31%, n=15), which also occurred in 28.7% of control patients (n=27). Wound dehiscence was reported in 36.2% (n=17) of thyroxine-supplemented patients compared to 10.8% of control patients (n=10). After adjusting for age, gender, hypertension diagnosis, and vascular disease diagnosis, the odds for wound dehiscence remained significantly greater for the thyroxine group compared to control patients (adjusted OR=3.7; 95% CI: (1.3, 11.4); p=0.01).

CONCLUSION

Overall, our results suggest increased wound dehiscence complications in the postoperative period for thyroxine-supplemented patients compared to control patients. This finding remained even after adjusting for the associated cardiovascular comorbidities seen in thyroxine-supplemented patients.

Anastomotic leakage after anterior resection for rectal cancer: risk factors

OBJECTIVE

The study aimed to identify risk factors for clinical anastomotic leakage (AL) after anterior resection for rectal cancer in a consecutive national cohort.

METHOD

All patients with an initial first diagnosis of colorectal adenocarcinoma were prospectively registered in a national database. The register included 1495 patients who had had a curative anterior resection between May 2001 and December 2004. The association of a number of patient- and procedure-related factors with clinical AL after anterior resection was analysed in a cohort design.

RESULTS

Anastomotic leakages occurred in 163 (11%) patients. In a multivariate analysis, the risk of AL was significantly increased in patients with tumours located below 10 cm from the anal verge if no faecal diversion was undertaken (OR 5.37 5 cm (tumour level from anal verge), 95% CI 2.10-13.7, OR 3.57 7 cm, CI 1.81-7.07 and OR 1.96 10 cm, CI 1.22-3.10), in male patients (OR 2.36, CI 1.18-4.71), in smokers (OR 1.88, CI 1.02-3.46), and perioperative bleeding (OR 1.05 for intervals of 100 ml blood loss, CI 1.02-1.07).

CONCLUSION

Anastomotic leakage after anterior resection for low rectal tumours is related to the level, male gender, smoking and perioperative bleeding. Faecal diversion is advisable after total mesorectal excision of low rectal tumours in order to prevent AL.

Sex hormones and mucosal wound healing

Wound healing studies, which have chiefly examined dermal tissues, have reported a female advantage in healing rates. In contrast, our laboratory recently demonstrated women heal mucosal wounds more slowly than men. We hypothesized sex hormones influence wound healing rates, possibly through their modulating effects on inflammation. This study involved 329 younger subjects aged 18-43 (165 women, 164 men) and 93 older subjects aged 50-88 (60 women, 33 men). A 3.5mm diameter wound was created on the hard oral palate and videographed daily to assess wound closure. Blood collected at the time of wounding was used to assess circulating testosterone, progesterone and estradiol levels, and in vitro cytokine production in response to LPS. No strong associations were observed between healing times and estradiol or progesterone levels. However, in younger subjects, lower testosterone levels related to faster wound closure. Conversely, in older women higher testosterone levels related to (1) lower inflammatory responses; and (2) faster healing times. No such relationships were seen in older men, or in women taking oral contraceptives or hormone replacement therapy [HRT]. Older women (50-54 years) not yet experiencing menopause healed similarly to younger women and dissimilarly from age-matched post-menopausal women. This suggests that the deleterious effects of aging on wound healing occur secondary to the effects of menopause. Supporting this, there was evidence in post-menopausal women that HRT augmented wound closure. Overall, this study suggests that human mucosal healing rates are modulated by testosterone levels. Based upon when between-group differences were observed, testosterone may impact upon the proliferative phase of healing which involves immune processes such as re-epithelialization and angiogenesis.

Sex dimorphism in wound healing: the roles of sex steroids and macrophage migration inhibitory factor

That endogenous sex steroid hormones profoundly influence the response to cutaneous injury is well established. How they and other factors combine to direct repair in male and female animals is much less well understood. Using a murine incisional wound-healing model, we investigated the roles of circulating sex steroids, macrophage migration inhibitory factor (MIF) (the mediator of delayed healing in ovariectomized animals), and hormone- and MIF-independent factors in controlling repair. We report that d 3 wounds, of comparable size in intact male and female mice, are significantly larger in ovariectomized female animals than in castrated males, suggesting that native sex hormones mask inherent underlying differences in the ways in which males and females respond to wounding. Wound MIF levels were comparable in intact male and female mice but greater in ovariectomized females than castrated males. Furthermore, wound levels of Jun activation domain-binding protein 1 (JAB1), a key factor by which MIF activates intracellular responses, were increased through ovariectomy and greater in ovariectomized females than castrated males. This difference in wound JAB1 levels may underscore the marked sex difference we observed in the responses of MIF knockout mice to the local application of MIF: healing was impaired in ovariectomized females but not castrated males. Separately, systemic treatment with androgens and estrogens yielded contrasting effects on repair in male and female animals. Collectively, the presented data indicate sex divergence in wound healing to be multifaceted, being strongly influenced by MIF and seemingly limited by the combined actions of gonadal steroids.

Association of amino-terminal propeptide of type III procollagen and acute myocardial rejection in male patients receiving heart transplantation

BACKGROUND

The amino-terminal propeptides of type I and III procollagens (PINP and PIIINP) are markers reflecting the status of collagen turnover. We hypothesized that measurement of these serum procollagen propeptides could be used to non-invasively assess acute rejection in heart transplant recipients.

METHODS

In heart transplant recipients, endomyocardial biopsy specimens taken at 6 and 12 months after surgery were used for study. PINP and PIIINP were measured postoperatively at 3, 6, and 12 months.

RESULTS

A total of 20 male heart transplant patients and seven male control subjects were enrolled. Five patients showed rejection 6 months after transplantation (group 1), while 15 patients showed no rejection (group 2). In group 2 patients, serum PINP and PIIINP levels decreased significantly 6 months after transplantation. In contrast, elevation of serum PINP and PIIINP levels persisted in group 1 patients 6 months after transplantation. At 6 months after transplantation, group 1 patients had significantly higher PIIINP levels than group 2 patients (p=0.025) and controls (p=0.003). After immunosuppressive therapy, all group 1 patients were free of rejection 12 months after transplantation and serial serum PIIINP levels decreased significantly in these patients.

CONCLUSIONS

Serum PIIINP levels represent a non-invasive method to reflect the occurrence and resolution of acute rejection.

An outcomes analysis of patients undergoing body contouring surgery after massive weight loss

BACKGROUND

Although published reports about technical management of massive weight loss patients are beginning to appear, risk factors for complications following body contouring operations are not known.

METHODS

A retrospective analysis of massive weight loss patients who had body contouring operations between March of 1998 and October of 2004 was performed. Demographic and surgical factors were analyzed. Outcome measures included seroma, wound dehiscence, thromboembolic complications, blood transfusion after surgery, and extended lengths of stay (>2 days).

RESULTS

A total of 139 patients were analyzed; 82.7 percent of them were female; mean age was 41 years. On multiple logistic regression, male gender was associated with significant risks for wound dehiscence (odds ratio, 6.4; p = 0.01). There were also trends toward increased risk for wound dehiscence with hypothyroidism (odds ratio, 4.3; p = 0.06) and Ehlers-Danlos syndrome (odds ratio, 18.7; p = 0.05). In terms of risk of blood transfusion, asthma and having three or more procedures were the two variables that emerged with significant association (odds ratio, 16.8 and 13.7, respectively; both p < 0.01). Increased length of stay to greater than 2 days was also significantly associated with having three or more procedures (odds ratio, 4.72; p < 0.01).

CONCLUSIONS

Male gender, hypothyroidism, and Ehlers-Danlos syndrome may be risk factors for wound dehiscence following body contour operations for massive weight loss. Asthma may be a marker of poor general health status, and asthmatic patients are at increased risk for requiring blood transfusions. Having three or more procedures is associated with an increased risk of blood transfusion and increased length of stay.

Hernia fibroblasts lack beta-estradiol-induced alterations of collagen gene expression

BACKGROUND

Estrogens are reported to increase type I and type III collagen deposition and to regulate Metalloproteinase 2 (MMP-2) expression. These proteins are reported to be dysregulated in incisional hernia formation resulting in a significantly decreased type I to III ratio. We aimed to evaluate the beta-estradiol mediated regulation of type I and type III collagen genes as well as MMP-2 gene expression in fibroblasts derived from patients with or without history of recurrent incisional hernia disease. We compared primary fibroblast cultures from male/female subjects without/without incisional hernia disease.

RESULTS

Incisional hernia fibroblasts (IHFs) revealed a decreased type I/III collagen mRNA ratio. Whereas fibroblasts from healthy female donors responded to beta-estradiol, type I and type III gene transcription is not affected in fibroblasts from males or affected females. Furthermore beta-estradiol had no influence on the impaired type I to III collagen ratio in fibroblasts from recurrent hernia patients.

CONCLUSION

Our results suggest that beta-estradiol does not restore the imbaired balance of type I/III collagen in incisional hernia fibroblasts. Furthermore, the individual was identified as an independent factor for the beta-estradiol induced alterations of collagen gene expression. The observation of gender specific beta-estradiol-dependent changes of collagen gene expression in vitro is of significance for future studies of cellular response.

Effect of lifestyle, gender and age on collagen formation and degradation

Historically, inappropriate lifestyle with an inadequate dietary intake of vitamin C has been associated with poor wound healing as a clinical manifestation of scurvy. In modern times, clinical evidence produced over the past few decades indicates that a modern lifestyle factor, such as smoking, together with biologic characteristics, like old age and male gender, are risk factors for abdominal wall hernia and recurrence. The pathologic pathways for these clinical observations are unclear. Yet, evidence from animal and human studies suggests that these exogenous and endogenous factors may have a negative impact on collagen metabolism, enhancing degradation and impairing formation.

Risk factors for tissue and wound complications in gastrointestinal surgery

BACKGROUND

Surgical site infections and disruption of sutured tissue are frequent complications following surgery. We aimed to assess risk factors predictive of tissue and wound complications in open gastrointestinal surgery.

METHODS

Data from 4855 unselected patients undergoing open gastrointestinal surgery from 1995 through 1998 were recorded in a clinical database and validated. The database embraced variables related to patient history, preoperative clinical condition, operative findings and severity, and the surgeon's training. Variables predictive of surgical site infection and dehiscence of sutured tissue within 30 days after surgery were assessed by multiple logistic regression analysis.

RESULTS

Following elective operation, the incidence of tissue and wound complications was 6% compared with 16% in emergency surgery (P < 0.001). These complications resulted in prolonged hospitalization in 50% of the patients and a 3-fold higher risk of reoperation but not increased mortality. Factors associated with complications following elective operations were smoking, comorbidity, and perioperative blood loss. Following emergency operations, male gender, peritonitis, and multiple operations were predictors of complications. Irrespective of elective or emergency surgery, the type of operation was a predictor of complications.

CONCLUSION

Factors known to affect the process of tissue and wound healing are independently associated with tissue and wound complications following gastrointestinal surgery.

Decreased collagen type I/III ratio in patients with recurring hernia after implantation of alloplastic prostheses

BACKGROUND

Abnormal collagen metabolism is suspected to play an important role in the pathogenesis of recurring inguinal and incisional hernias. Whereas alloplastic prostheses are nowadays routinely used, the quantity and quality of collagen formation after repair in humans has not been analysed in a large cohort.

METHOD

Seventy-eight prostheses (Prolene, Atrium, Marlex, Vypro, Mersilene, Gore-Tex) implanted for inguinal and incisional hernia repair were explanted because of recurrence, chronic pain or infection. The mean implantation period was 17.9+/-11.2 (range 0.5-48) months. Collagen formation was investigated quantitatively (collagen-protein ratio) and qualitatively (collagen type I/III ratio). Results were related to clinical data that included gender, age, implantation period, indication for implantation/explantation, type and location of prosthesis.

RESULTS

Mean collagen-protein ratio was 45.3+/-8.5 microg/mg, with significant differences between male (43.8+/-9.1 microg/mg) and female tissue samples (48.1+/-6.8 microg/mg, P=0.033). The mean collagen type I/III ratio of all samples investigated was 2.1+/-1.4. Samples explanted for recurring hernias exhibited a significantly decreased ratio (1.3+/-0.7, P<0.05) compared to samples explanted because of pain (3.4+/-1.2) or infection (2.9+/-1.6). Multivariate analysis excluded independent effects of age, gender, indication for implantation of prostheses, location and implantation period on collagen type I/III ratio.

CONCLUSION

The present study confirms the importance of a biological approach, next to technical aspects, to the understanding of the pathogenesis of recurrent hernia formation and underscores the presence of a disturbed scarring process. The composition of scar tissue with a lowered collagen type I/III ratio and, therefore, reduced tensile strength may be a major contribution to hernia recurrence.

Effect of a specialized amino acid mixture on human collagen deposition

OBJECTIVE

To examine the effect of arginine, beta-hydroxy-beta-methylbutyrate (HMB), and glutamine supplementation on wound collagen accumulation in a double-blind, randomized study.

SUMMARY BACKGROUND DATA

Control of wound collagen synthesis has been an elusive goal for clinicians and scientists alike. In many clinical instances, it is desired to increase collagen deposition as a means of enhancing wound strength and integrity. Arginine, a semiessential amino acid, has been shown to increase wound collagen accumulation in rodents and humans. HMB, a metabolite of leucine, regulates muscle proteolysis in animals and humans and increases collagen deposition in rodents.

METHODS

Thirty-five healthy, nonsmoking human volunteers 70 years or older were enrolled and underwent subcutaneous implantation of two small, sterile polytetrafluoroethylene (PTFE) tubes into the deltoid region under strict aseptic techniques. The tubes were 1 mm in diameter and 6 cm in length with pore size of 90 to 120 microm to allow optimal ingrowth of fibroblasts and the deposition of matrix. Eighteen volunteers (mean age 75.4 years; 2 men, 16 women) were randomized to receive daily supplementation of 14 g arginine, 3 g HMB, and 14 g glutamine (total nitrogen 3.59 g) in two divided doses. The control group (n = 17; mean age 75.3 years; 6 men, 11 women) received an isonitrogenous, isocaloric supplementation of nonessential amino acids. Catheters were removed at 7 and 14 days postimplantation and analyzed for hydroxyproline (OHP, nmol/cm catheter, an index of collagen accumulation) and alpha-amino nitrogen (alpha-AN, mmol/cm, an index of total protein deposition).

RESULTS

Supplements were well tolerated, without any reported side effects. Supplementation with the specialized amino acid mixture led to a significant rise in plasma arginine and ornithine levels. The specialized amino acid supplement led to a significant increase in collagen deposition (as reflected by OHP content) in the PTFE tubes without an effect on total protein accumulation.

CONCLUSIONS

Collagen synthesis is significantly enhanced in healthy elderly volunteers by the oral administration of a mixture of arginine, HMB, and glutamine. This provides a safe nutritional means for increasing wound repair in patients.