Release of insulin from PLGA-alginate dressing stimulates regenerative healing of burn wounds in rats.

Burn wound healing involves a complex set of overlapping processes in an environment conducive to ischaemia, inflammation and infection costing $7.5 billion/year in the U.S.A. alone, in addition to the morbidity and mortality that occur when the burns are extensive. We previously showed that insulin, when topically applied to skin excision wounds, accelerates re-epithelialization and stimulates angiogenesis. More recently, we developed an alginate sponge dressing (ASD) containing insulin encapsulated in PLGA [poly(D,L-lactic-co-glycolic acid)] microparticles that provides a sustained release of bioactive insulin for >20 days in a moist and protective environment. We hypothesized that insulin-containing ASD accelerates burn healing and stimulates a more regenerative, less scarring healing. Using heat-induced burn injury in rats, we show that burns treated with dressings containing 0.04 mg insulin/cm(2) every 3 days for 9 days have faster closure, a higher rate of disintegration of dead tissue and decreased oxidative stress. In addition, in insulin-treated wounds, the pattern of neutrophil inflammatory response suggests faster clearing of the burned dead tissue. We also observe faster resolution of the pro-inflammatory macrophages. We also found that insulin stimulates collagen deposition and maturation with the fibres organized more like a basket weave (normal skin) than aligned and cross-linked (scar tissue). In summary, application of ASD-containing insulin-loaded PLGA particles on burns every 3 days stimulates faster and more regenerative healing. These results suggest insulin as a potential therapeutic agent in burn healing and, because of its long history of safe use in humans, insulin could become one of the treatments of choice when repair and regeneration are critical for proper tissue function.

Luteolin, ellagic acid and punicic acid are natural products that inhibit prostate cancer metastasis.

Prostate cancer (PCa) is the second cause of cancer deaths in men in the USA. When the cancer recurs, early stages can be controlled with hormone ablation therapy to delay the rate of cancer progression but, over time, the cancer overcomes its hormone dependence, becomes highly aggressive and metastasizes. Clinical trials have shown that pomegranate juice (PJ) inhibits PCa progression. We have previously shown that the PJ components luteolin (L), ellagic acid (E) and punicic acid (P) together inhibit growth of hormone-dependent and -independent PCa cells and inhibit their migration and chemotaxis towards CXCL12, a chemokine that is important in PCa metastasis. On the basis of these findings, we hypothesized that L+E+P inhibit PCa metastasis in vivo. To test this possibility, we used a severe combined immunodeficiency mouse model in which luciferase-expressing human PCa cells were injected subcutaneously near the prostate. Tumor progression was monitored with bioluminescence imaging weekly. We found that L+E+P inhibits PC-3M-luc primary tumor growth, inhibits the CXCL12/CXCR4 axis for metastasis and none of the tumors metastasized. In addition, L+E+P significantly inhibits growth and metastasis of highly invasive Pten (-/-) ;K-ras (G12D) prostate tumors. Furthermore, L+E+P inhibits angiogenesis in vivo, prevents human endothelial cell (EC) tube formation in culture and disrupts preformed EC tubes, indicating inhibition of EC adhesion to each other. L+E+P also inhibits the angiogenic factors interleukin-8 and vascular endothelial growth factor as well as their induced signaling pathways in ECs. In conclusion, these results show that L+E+P inhibits PCa progression and metastasis.

Ovarian torsion after hysterectomy and oophoropexy.

Ovarian torsion (OT) is a medical emergency which can have significant clinical consequences. It is surgically treated by either detorsion with or without oophoropexy, or oophorectomy. In this report, a case of left OT is described after prior hysterectomy and bilateral prophylactic oophoropexy three years prior. The patient presented with progressive left flank and abdominal pain. The diagnosis of torsion was made using a combination of CT and MR imaging with confirmation at surgery and pathology. At laparoscopic surgery, the left ovary was found at the level of iliac crest posterior to the descending colon. The ovary was torsed with hemorrhagic infarction. It was successfully removed. The patient was discharged postoperative day one and is now free of symptoms and complaints. OT is rarely reported after hysterectomy and oophoropexy. This case demonstrates that OT should be kept in the differential even in patients post hysterectomy and/or oophoropexy.

Severe Pelvic Fracture in the Elderly: High Morbidity, Mortality, and Resource Utilization.

Severe pelvic fractures (PF) in the elderly are common and analysis of outcomes and resource utilization are lacking. Using the National Trauma Databank (2007-2016), 13 267 patients aged ≥65 years with severe PF (Abbreviated Injury Scale [AIS] pelvis ≥3; AIS 3 = 10 388; AIS 4 = 2124; AIS 5 = 805) were studied. Demographic data, management, resource utilization, complications, and mortality were analyzed for each group. Data are represented as % or median interquartile range (IQR). Multivariate logistic regression analyzed risk factors for mortality, Intensive Care Unit (ICU) admission, and ventilator use. Median age was 77, and most of them were females (59%). Falls occurred in 52%, motor vechicle crash in 21.5%, and pedestrian struck in 11.6%. Median injury severity score was 16 (IQR: 9,27). Shock on admission (9.4%) increased with injury severity. Glasgow Coma Scale < 8 occurred in 8%. Blood transfusion increased with injury severity (17%, 29%, and 51%). Angiography occurred in 9%, external fixation in 4%, internal fixation in 16%, and pelvic packing in 1%, the majority in the AIS 5 group. Overall, 46% required ICU admission and 30% underwent mechanical ventilation; median Hospital Length of Stay was 6 (IQR 4,11), ICU length of stay was 5 (IQR 2,10), and median ventilator days were 4 (IQR 1-11). Mortality rate was 13.3% (AIS 3 = 10%, AIS 4 = 19%, and AIS 5 = 44%).Severe PF in the elderly is associated with high resource utilization, complications, and mortality.

Management and Outcomes of Acute Appendicitis in the Presence of Cirrhosis: A Nationwide Analysis.

Best management for acute appendicitis (AA) in adults with liver cirrhosis is controversial and needs more investigation. We aimed to examine the impact of different treatment modalities on outcomes in this complex patient population. The Nationwide Inpatient Sample database from 2012 to 2014 was queried to identify AA patients with no cirrhosis, compensated cirrhosis (CC), and decompensated cirrhosis (DC). Each cohort was further stratified according to the treatment type: nonoperative management, open appendectomy, and laparoscopic appendectomy (LA). Chi-square, ANOVA, and binary regression analyses were used to determine differences between groups and risk factors for mortality and complications, with P < 0.05 considered statistically significant. A total of 108,289 AA patients were analyzed; of those, 304 with CC and 134 with DC were identified. Compared with CC and no cirrhosis, DC patients had significantly higher mortality, higher cost, and longer hospital length of stay. LA is accompanied by higher survival, lower cost, shorter duration of hospitalization, and lower incidence of complications across all groups. We conclude that LA is the best management strategy for AA in cirrhotic patients. Even in decompensated cirrhotics, which are associated with worse clinical outcomes, LA is still a favorable option over open appendectomy and nonoperative management.

Improved burn wound healing by the antimicrobial peptide LLKKK18 released from conjugates with dextrin embedded in a carbopol gel.

Antimicrobial peptides (AMPs) are good candidates to treat burn wounds, a major cause of morbidity, impaired life quality and resources consumption in developed countries. We took advantage of a commercially available hydrogel, Carbopol®, a vehicle for topical administration that maintains a moist environment within the wound site. We hypothesized that the incorporation of LLKKK18 conjugated to dextrin would improve the healing process in rat burns. Whereas the hydrogel improves healing, LLKKK18 released from the dextrin conjugates further accelerated wound closure, and simultaneously improving the quality of healing. Indeed, the release of LLKKK18 reduced oxidative stress and inflammation (low neutrophil and macrophage infiltration and pro-inflammatory cytokines levels). Importantly, it induced a faster resolution of the inflammatory stage through early M2 macrophage recruitment. In addition, LLKKK18 stimulated angiogenesis (increased VEGF and microvessel development in vivo). Moreover, collagen staining evaluated by Masson's Trichrome was visually much more intense after treatment with LLKKK18, suggesting higher collagen deposition. Overall, we generated an effective, safe and inexpensive formulation that maintains a moist environment in the wound, easy to apply and remove, and with potential to prevent infection due to the presence of an antimicrobial peptide. These findings propel us to further study this LLKKK18-containing formulation, setting the foundations towards a potential therapeutic approach for burn wound treatment. STATEMENT OF SIGNIFICANCE: This work presents a newly developed formulation that holds great potential as a therapeutic approach for burn treatment. It is based on the sustained delivery of an antimicrobial peptide - LLKKK18 - from conjugates with dextrin, after degradation of dextrin backbone upon exposure to wound α-amylases. Conjugates were further embedded in Carbopol®, a commercially available hydrogel, suitable for topical administration and that provides a moist environment to the wound. Overall, we obtained an efficient, safe and non-expensive formulation that improves burn wound healing, maintains a moist environment within the wound, is easy to apply-and-remove, and has potential to prevent infection due to the presence of an antimicrobial peptide. Importantly, this is the first time the wound healing ability of LLKKK18 is demonstrated and that its main mechanisms of action are identified.

Generating and reversing chronic wounds in diabetic mice by manipulating wound redox parameters.

By 2025, more than 500 M people worldwide will suffer from diabetes; 125 M will develop foot ulcer(s) and 20 M will undergo an amputation, creating a major health problem. Understanding how these wounds become chronic will provide insights to reverse chronicity. We hypothesized that oxidative stress (OS) in wounds is a critical component for generation of chronicity. We used the db/db mouse model of impaired healing and inhibited, at time of injury, two major antioxidant enzymes, catalase and glutathione peroxidase, creating high OS in the wounds. This was necessary and sufficient to trigger wounds to become chronic. The wounds initially contained a polymicrobial community that with time selected for specific biofilm-forming bacteria. To reverse chronicity we treated the wounds with the antioxidants α-tocopherol and N-acetylcysteine and found that OS was highly reduced, biofilms had increased sensitivity to antibiotics, and granulation tissue was formed with proper collagen deposition and remodeling. We show for the first time generation of chronic wounds in which biofilm develops spontaneously, illustrating importance of early and continued redox imbalance coupled with the presence of biofilm in development of wound chronicity. This model will help decipher additional mechanisms and potentially better diagnosis of chronicity and treatment of human chronic wounds.

A novel model of chronic wounds: importance of redox imbalance and biofilm-forming bacteria for establishment of chronicity.

Chronic wounds have a large impact on health, affecting ∼6.5 M people and costing ∼$25B/year in the US alone. We previously discovered that a genetically modified mouse model displays impaired healing similar to problematic wounds in humans and that sometimes the wounds become chronic. Here we show how and why these impaired wounds become chronic, describe a way whereby we can drive impaired wounds to chronicity at will and propose that the same processes are involved in chronic wound development in humans. We hypothesize that exacerbated levels of oxidative stress are critical for initiation of chronicity. We show that, very early after injury, wounds with impaired healing contain elevated levels of reactive oxygen and nitrogen species and, much like in humans, these levels increase with age. Moreover, the activity of anti-oxidant enzymes is not elevated, leading to buildup of oxidative stress in the wound environment. To induce chronicity, we exacerbated the redox imbalance by further inhibiting the antioxidant enzymes and by infecting the wounds with biofilm-forming bacteria isolated from the chronic wounds that developed naturally in these mice. These wounds do not re-epithelialize, the granulation tissue lacks vascularization and interstitial collagen fibers, they contain an antibiotic-resistant mixed bioflora with biofilm-forming capacity, and they stay open for several weeks. These findings are highly significant because they show for the first time that chronic wounds can be generated in an animal model effectively and consistently. The availability of such a model will significantly propel the field forward because it can be used to develop strategies to regain redox balance that may result in inhibition of biofilm formation and result in restoration of healthy wound tissue. Furthermore, the model can lead to the understanding of other fundamental mechanisms of chronic wound development that can potentially lead to novel therapies.

Cigarette smoke toxins deposited on surfaces: implications for human health.

Cigarette smoking remains a significant health threat for smokers and nonsmokers alike. Secondhand smoke (SHS) is intrinsically more toxic than directly inhaled smoke. Recently, a new threat has been discovered - Thirdhand smoke (THS) - the accumulation of SHS on surfaces that ages with time, becoming progressively more toxic. THS is a potential health threat to children, spouses of smokers and workers in environments where smoking is or has been allowed. The goal of this study is to investigate the effects of THS on liver, lung, skin healing, and behavior, using an animal model exposed to THS under conditions that mimic exposure of humans. THS-exposed mice show alterations in multiple organ systems and excrete levels of NNAL (a tobacco-specific carcinogen biomarker) similar to those found in children exposed to SHS (and consequently to THS). In liver, THS leads to increased lipid levels and non-alcoholic fatty liver disease, a precursor to cirrhosis and cancer and a potential contributor to cardiovascular disease. In lung, THS stimulates excess collagen production and high levels of inflammatory cytokines, suggesting propensity for fibrosis with implications for inflammation-induced diseases such as chronic obstructive pulmonary disease and asthma. In wounded skin, healing in THS-exposed mice has many characteristics of the poor healing of surgical incisions observed in human smokers. Lastly, behavioral tests show that THS-exposed mice become hyperactive. The latter data, combined with emerging associated behavioral problems in children exposed to SHS/THS, suggest that, with prolonged exposure, they may be at significant risk for developing more severe neurological disorders. These results provide a basis for studies on the toxic effects of THS in humans and inform potential regulatory policies to prevent involuntary exposure to THS.