Jennifer K. Plichta

Chronic Alcohol Exposure Renders Epithelial Cells Vulnerable to Bacterial Infection

Despite two centuries of reports linking alcohol consumption with enhanced susceptibility to bacterial infections and in particular gut-derived bacteria, there have been no studies or model systems to assess the impact of long-term alcohol exposure on the ability of the epithelial barrier to withstand bacterial infection. It is well established that acute alcohol exposure leads to reduction in tight and adherens junctions, which in turn leads to increases in epithelial cellular permeability to bacterial products, leading to endotoxemia and a variety of deleterious effects in both rodents and human. We hypothesized that reduced fortification at junctional structures should also reduce the epithelial barrier’s capacity to maintain its integrity in the face of bacterial challenge thus rendering epithelial cells more vulnerable to infection. In this study, we established a cell-culture based model system for long-term alcohol exposure to assess the impact of chronic alcohol exposure on the ability of Caco-2 intestinal epithelial cells to withstand infection when facing pathogenic bacteria under the intact or wounded conditions. We report that daily treatment with 0.2% ethanol for two months rendered Caco-2 cells far more susceptible to wound damage and cytotoxicity caused by most but not all bacterial pathogens tested in our studies. Consistent with acute alcohol exposure, long-term ethanol exposure also adversely impacted tight junction structures, but in contrast, it did not affect the adherens junction. Finally, alcohol-treated cells partially regained their ability to withstand infection when ethanol treatment was ceased for two weeks, indicating that alcohol’s deleterious effects on cells may be reversible.

Sugar-coating wound repair: a review of FGF-10 and dermatan sulfate in wound healing and their potential application in burn wounds.

Thousands of patients suffer from burn injuries each year, yet few therapies have been developed to accelerate the wound healing process. Most fibroblast growth factors (FGFs) have been extensively evaluated but only a few have been found to participate in the wound healing process. In particular, FGF-10 is robustly increased in the wound microenvironment after injury and has demonstrated some ability to promote wound healing in vitro and in vivo. Glycosaminoglycans are linear carbohydrates that participate in wound repair by influencing cytokine/growth factor localization and interaction with cognate receptors. Dermatan sulfate (DS) is the most abundant glycosaminoglycan in human wound fluid and has been postulated to be directly involved in the healing process. Recently, the combination of FGF-10 and DS demonstrated the potential to accelerate wound healing via increased keratinocyte proliferation and migration. Based on these preliminary studies, DS may serve as a cofactor for FGF-10, and together they are likely to expedite the healing process by stimulating keratinocyte activity. As a specific subtype of wounds, the overall healing process of burn injuries does not significantly differ from other types of wounds, where optimal repair results in matrix regeneration and complete reepithelialization. At present, standard burn treatment primarily involves topical application of antimicrobial agents, while no routine therapies target acceleration of reepithelialization, the key to wound closure. Thus, this novel therapeutic combination could be used in conjunction with some of the current therapies, but it would have the unique ability to initiate wound healing by stimulating keratinocyte epithelialization.

Local burn injury impairs epithelial permeability and antimicrobial peptide barrier function in distal unburned skin.

Objectives:Our objective was to characterize the mechanisms by which local burn injury compromises epithelial barrier function in burn margin, containing the elements necessary for healing of the burn site, and in distal unburned skin, which serves as potential donor tissue. Design:Experimental mouse scald burn injury. Setting:University Research Laboratory. Subjects:C57/Bl6 Male mice, 8–12 weeks old. Interventions:To confirm that dehydration was not contributing to our observed barrier defects, in some experiments mice received 1 mL of saline fluid immediately after burn, while a subgroup received an additional 0.5 mL at 4 hours and 1 mL at 24 hours following burn. We then assessed skin pH and transepidermal water loss every 12 hours on the burn wounds for 72 hours postburn. Measurements and Main Results:Burn margin exhibited increased epidermal barrier permeability indicated by higher pH, greater transepidermal water loss, and reduced lipid synthesis enzyme expression and structural protein production up to 96 hours postburn. By contrast, antimicrobial peptide production and protease activity were elevated in burn margin. Skin extracts from burn margin did not exhibit changes in the ability to inhibit bacterial growth. However, distal unburned skin from burned mice also demonstrated an impaired response to barrier disruption, indicated by elevated transepidermal water loss and reduced lipid synthesis enzyme and structural protein expression up to 96 hours postburn. Furthermore, skin extracts from distal unburned skin exhibited greater protease activity and a reduced capacity to inhibit bacterial growth of several skin pathogens. Finally, we established that antimicrobial peptide levels were also altered in the lung and bladder, which are common sites of secondary infection in burn-injured patients. Conclusions:These findings reveal several undefined deficiencies in epithelial barrier function at the burn margin, potential donor skin sites, and organs susceptible to secondary infection. These functional and biochemical data provide novel insights into the mechanisms for graft failure and secondary infection after burn injury.

Oncologic Safety of Nipple-Sparing Mastectomy in Women with Breast Cancer

BACKGROUND Nipple-sparing mastectomy (NSM) has gained popularity for breast cancer treatment and prevention. There are limited data about long-term oncologic safety of this procedure. STUDY DESIGN We reviewed oncologic outcomes of consecutive therapeutic NSM at a single institution. Nipple-sparing mastectomy was offered to patients with no radiologic or clinical evidence of nipple involvement. RESULTS There were 2,182 NSM performed from 2007 to 2016. Long-term outcomes were assessed in the 311 NSM performed in 2007 to 2012 for Stages 0 to 3 breast cancer; 240 (77%) NSM were for invasive cancer and 71 (23%) were for ductal carcinoma in situ. At 51 months median follow-up, 17 patients developed a recurrence of their cancer. Estimated disease-free survival was 95.7% at 3 years and 92.3% at 5 years. There were 11 (3.7%) locoregional recurrences and 8 (2.7%) distant recurrences; 2 patients had simultaneous locoregional and distant recurrences. There were 2 breast cancer-related deaths in patients with isolated distant recurrences. No patient in the entire 2,182 NSM cohort has had a recurrence in the retained nipple-areola complex. CONCLUSIONS Rates of locoregional and distant recurrence are acceptably low after nipple-sparing mastectomy in patients with breast cancer. No patient in our series has had a recurrence involving the retained nipple areola complex.

Local Burn Injury Promotes Defects in the Epidermal Lipid and Antimicrobial Peptide Barriers in Human Autograft Skin and Burn Margin: Implications for Burn Wound Healing and Graft Survival.

Burn injury increases the risk of morbidity and mortality by promoting severe hemodynamic shock and risk for local or systemic infection. Graft failure due to poor wound healing or infection remains a significant problem for burn subjects. The mechanisms by which local burn injury compromises the epithelial antimicrobial barrier function in the burn margin, containing the elements necessary for healing of the burn site, and in distal unburned skin, which serves as potential donor tissue, are largely unknown. The objective of this study was to establish defects in epidermal barrier function in human donor skin and burn margin, to identify potential mechanisms that may lead to graft failure and/or impaired burn wound healing. In this study, we established that epidermal lipids and respective lipid synthesis enzymes were significantly reduced in both donor skin and burn margin. We further identified diverse changes in the gene expression and protein production of several candidate skin antimicrobial peptides (AMPs) in both donor skin and burn margin. These results also parallel changes in cutaneous AMP activity against common burn wound pathogens, aberrant production of epidermal proteases known to regulate barrier permeability and AMP activity, and greater production of proinflammatory cytokines known to be induced by AMPs. These findings suggest that impaired epidermal lipid and AMP regulation could contribute to graft failure and infectious complications in subjects with burn or other traumatic injury.

Nicotinic Acetylcholine Receptor Stimulation Impairs Epidermal Permeability Barrier Function and Recovery and Modulates Cornified Envelope Proteins

AIM To characterize how nicotinic acetylcholine receptors (nAChRs) influence epidermal barrier function and recovery following prolonged stress or direct nAChR activation or antagonism. MAIN METHODS Mice were subjected to psychological stress or treated topically with nAChR agonist or antagonist for 3 days. We assessed barrier permeability and recovery by measuring transepidermal water loss (TEWL) before and after barrier disruption. In parallel, we analyzed the production and localization of several epidermal cornified envelope proteins in mouse skin and in human EpiDerm™ organotypic constructs stimulated with a nAChR agonist (nicotine) and/or a nAChR selective antagonist (α-bungarotoxin). KEY FINDINGS We determined that psychological stress in mice impairs barrier permeability function and recovery, an effect that is reversed by application of the α7 selective nAChR antagonist, α-bungarotoxin (Bung). In the absence of stress, both topical nicotine or Bung treatment alone impaired barrier permeability. We further observed that stress, topical nicotine, or topical Bung treatment in mice influenced the abundance and/or localization of filaggrin, loricrin, and involucrin. Similar alterations in these three major cornified envelope proteins were observed in human EpiDerm™ cultures. SIGNIFICANCE Perceived psychological stress and nicotine usage can both initiate or exacerbate several dermatoses by altering the cutaneous permeability barrier. Modulation of nAChRs by topical agonists or antagonists may be used to improve epidermal barrier function in skin diseases associated with defects in epidermal barrier permeability.

The Changing Spectrum of Surgically Treated Cystic Neoplasms of the Pancreas

Introduction. While the incidence of pancreatic cystic lesions has steadily increased, we sought to evaluate the changes in their surgical management. Methods. Patients with pancreatic cystic lesions who underwent surgical resection from 2003 to 2013 were identified. Clinicopathologic factors were analyzed and compared to a similar cohort from 1992 to 2002. Results. There were 134 patients with pancreatic cystic lesions who underwent surgical resection from 2003 to 2013, compared to 73 from 1992 to 2002. The most common preoperative imaging was a CT scan, although 66% underwent EUS and 63% underwent biopsy. Pathology included 18 serous, 47 mucinous, 11 pseudopapillary, and 58 intraductal papillary mucinous neoplasms (IPMN). In comparing cohorts, there were significantly fewer serous lesions and more IPMN. Postoperative complication rates were similar, and perioperative mortality rates were comparable. Conclusion. There has been a dramatic change in surgically treated pancreatic cystic tumors over the past two decades. Our data suggests that the incorporation of new imaging and diagnostic tests has led to greater detection of cystic tumors and a decreased rate of potentially unnecessary resections. Therefore, all patients with cystic pancreatic lesions should undergo a focused CT-pancreas, and an EUS biopsy should be considered, in order to best select those that would benefit from surgical resection.

Breast cancer risk models: a comprehensive overview of existing models, validation, and clinical applications.

Numerous models have been developed to quantify the combined effect of various risk factors to predict either risk of developing breast cancer, risk of carrying a high-risk germline genetic mutation, specifically in the BRCA1 and BRCA2 genes, or the risk of both. These breast cancer risk models can be separated into those that utilize mainly hormonal and environmental factors and those that focus more on hereditary risk. Given the wide range of models from which to choose, understanding what each model predicts, the populations for which each is best suited to provide risk estimations, the current validation and comparative studies that have been performed for each model, and how to apply them practically is important for clinicians and researchers seeking to utilize risk models in their practice. This review provides a comprehensive guide for those seeking to understand and apply breast cancer risk models by summarizing the majority of existing breast cancer risk prediction models including the risk factors they incorporate, the basic methodology in their development, the information each provides, their strengths and limitations, relevant validation studies, and how to access each for clinical or investigative purposes.

Burn Injury Alters Epidermal Cholinergic Mediators and Increases Hmgb1 and Caspase 3 in Autologous Donor Skin and Burn Margin.

ABSTRACT Burn wound healing complications, such as graft failure or infection, are a major source of morbidity and mortality in burn patients. The mechanisms by which local burn injury alters epidermal barrier function in autologous donor skin and surrounding burn margin are largely undefined. We hypothesized that defects in the epidermal cholinergic system may impair epidermal barrier function and innate immune responses. The objective was to identify alterations in the epidermal cholinergic pathway, and their downstream targets, associated with inflammation and cell death. We established that protein levels, but not gene expression, of the &agr;7 nicotinic acetylcholine receptor (CHRNA7) were significantly reduced in both donor and burn margin skin. Furthermore, the gene and protein levels of an endogenous allosteric modulator of CHRNA7, secreted mammalian Ly-6/ urokinase-type plasminogen activator receptor-related protein-1, and acetylcholine were significantly elevated in donor and burn margin skin. As downstream proteins of inflammatory and cell death targets of nAChR activation, we found significant elevations in epidermal High Mobility Group Box Protein 1 and caspase 3 in donor and burn margin skin. Lastly, we employed a novel in vitro keratinocyte burn model to establish that burn injury influences the gene expression of these cholinergic mediators and their downstream targets. These results indicate that defects in cholinergic mediators and inflammatory/apoptotic molecules in donor and burn margin skin may directly contribute to graft failure or infection in burn patients.

Should all branch-duct intraductal papillary mucinous neoplasms be resected?

BACKGROUND The relationship between branch-duct intraductal papillary mucinous neoplasms (IPMNs) and malignancy remains controversial and difficult to assess. METHODS Between January 1, 1999 and January 1, 2013, we identified 84 patients with IPMN who underwent resection. RESULTS Preoperatively, 55 patients underwent endoscopic ultrasounds and 58 underwent biopsy. Only 7 lesions were specified preoperatively as branch-duct, which inconsistently correlated with the surgical specimen. Of the 82 patients where the duct was specified, there were 33 malignant lesions. There was no correlation between branch-duct origin and invasive carcinoma. Malignant tumor size did not significantly differ by the duct of origin. Of the 28 patients with invasive carcinoma, branch-duct lesions were significantly associated with the presence of positive lymph nodes, perineural invasion, and lymphovascular invasion. CONCLUSIONS Our study supports the resection criteria for branch-duct IPMN based on size and symptoms. However, it also questions the reliability of our preoperative testing to rule out malignant branch-duct IPMN lesions.