Charles F. Bellows

Aim: Mesenchymal stem cells (MSCs) are pluripotent cells with significant therapeutic potential. The objective of this study was to examine the inflammatory profile of MSCs cultured under different... Graphical abstract

Background: Chronic wounds are a serious medical condition affecting over 6 million people in the United States. Biofilms, which alter the host immune response and establish a microenvironment that prevents wound healing, are intimately associated with the development of chronic wounds. Current treatment options do not specifically target the underlying molecular mechanisms of biofilm pathology. Paracrine factors secreted by mesenchymal stem cells (MSCs) have been demonstrated to play an important role in wound healing. The objective of this study was to examine the effects of the paracrine factors secreted from MSCs on reducing infection and accelerating wound closure in biofilm-infected wounds.Methods: MSCs were cultured by seeding on an extracellular matrix (ECM). The supernatant from MSCs containing paracrine factors were applied to mature Pseudomonas aeruginosa biofilms in vitro and the number of viable bacteria were quantitated. BALB/cJ mice were wounded and infected with P. aeruginosa biofilms and the paracrine factors from reprogrammed MSCs were applied topically. The wound surface area and colony forming units counts of the treatment group were compared to control (culture media) and biofilm (untreated) groups. Results: The paracrine factors from MSCs grown on ECM were found to reduce P. aeruginosa biofilm growth significantly (P<0.01). Wounds in the treatment group had lower bacterial counts and an increased rate of wound closure compared to non-treated mice wounds. Conclusion: The results indicate that paracrine factors from reprogrammed MSCs accelerated wound healing and reduced the bacterial burden in biofilm-infected wounds. Future studies are needed to further characterize this phenomenon.

Role of oral and intravenous pre-operative antibiotics in elective colon surgery

Biologic prosthetics are increasingly used for the repair of abdominal wall hernia defects but can become infected as a result of peri- or early post-operative bacterial contamination. Data evaluating biofilm formation on biologic prosthetics is lacking. The aim of this study was to investigate the influence of different biologic prosthetics on the growth behavior of two different bacterial species and their ability to form biofilms. Methicillin resistant Staphylococcus aureus (MRSA) or Pseudomrnonas aeruginosa were incubated on disks of two biologic prosthetics-human acellular dermis (ADM), and porcine small intestinal submucosa (SIS). The bacteria were allowed to attach to the prosthetics and propagate into mature biofilms for 24 hours at 370C. Images of biofilms were obtained using confocal microscopy and scanning electron microscopy (SEM). The number of viable cells and the biofilm biomass were quantified by colony forming units (CFUs) and crystal violet staining respectively. Analysis of variance was performed to compare the mean values for the different prosthetics. Each biologic matrix had a distinct surface characteristic. SEM visualized mature biofilms characterized by highly organized multi-cellular structures on surface of both biologic prosthetics. Quantification of bacterial growth over time showed that ADM had the lowest CFUs and biofilm biomass at 24 hours post-inoculation compared to SIS for both bacterial strains. MRSA and P. aeruginosa can form mature biofilms on biologic prosthetics but the relative abundance of the biofilm varies on different prosthetic constructs. Biologic material composition and manufacturing methods may influence bacterial adherence.

Medicaid patients tend to have poor access to care and suffer from more obesity and obesity-related co-morbidities compared to their privately insured counterparts. The impact of Medicaid status on outcomes after laparoscopic sleeve gastrectomy (LSG) is unknown. The aim of this study was to identify factors that influence outcomes following LSG in the adult Medicaid population of Louisiana with particular focus on adherence to bariatric aftercare attendance and access to care. A retrospective review of 63 Medicaid patients undergoing LSG was performed. Demographic data, access to care, weight, co-morbidities morbidity, and mortality were analyzed. Changes in weight and obesity-related co-morbidities were analyzed for patients with ≥12 months of follow-up. Regression analyses were used for estimating the relationships among variables. The majority of patients were female and non-Caucasian. The mean age was 38.6 years. Morbidity was 16% and mortality was 0%. The average distance traveled to clinic was 71.9 miles. Within the first year only 10% of the patients attended all post-operative clinic visits. A multiple logistic model showed that the only predictor of clinic attendance was increased age. At a mean follow-up of 17.7 months, the mean percent excess body weight loss was 47.2%. Greater pre-surgical weight was the only variable associated with suboptimal weight loss. Improvement or resolution of all major co-morbidities was seen in 65% of patients. Medicaid patients had a poor attendance at bariatric surgery follow up appointments. Since long-term follow-up is critical, we needed to develop strategies that will optimize follow-up in this patient population.

Colon cancer stem cells (CSCs) are implicated in colorectal cancer carcinogenesis, metastasis, and therapeutic resistance. The identification of these cells could help to develop novel therapeutic strategies. Doublecortin-like kinase 1 (DCLK1) has been viewed as a marker for gastrointestinal stem cells that fuel the self-renewal process, however others view them as a marker of Tuft cells or as an enteroendocrine subtype. The purpose of this study was to use a colon cancer cell line to identify and characterize the stem-like characteristics of the DCLK1+ cell population. To enrich stem-like cells, HCT116 cells (derived from colon adenocarcinomas) were cultured using serum-free media to form spheres under both normal oxygen and hypoxia condition. DCLK1 transcript expression in the adherent parental cells and spheroids was quantified using quantitative real time reverse transcription- polymerase chain reaction [(q)RT-PCR]. DCLK1 protein expression was determined using flow cytometry. Self-renewal capability from adherent parental cells and spheroids was determined using extreme limiting dilution analysis (ELDA). Under both normal oxygen and hypoxia condition, the adherent parental cells were composed of cells that express low levels of DCLK1. However, spheroids exhibited an increased frequency of cells expressing DCLK1 on both mRNA and protein levels. Cells derived from spheroids also possess stronger self-renewal capability. The higher fraction of DCLK1+ cells exhibited by spheroids and hypoxia reflects the stem-like characteristics of these cells. DCLK1 may represent an ideal marker to study and develop effective strategies to overcome chemo-resistance and relapse of colon cancer.

Biologic grafts are rarely used for inguinal herniorrhaphy. The aim of this study was to compare the clinical outcomes between patients undergoing a Lichtenstein’s hernioplasty with a porcine mesh versus a standard synthetic. A prospective, randomized, double-blinded multicenter, evaluation of inguinal hernia repair was conducted between 2008 and 2010. Lichtenstein hernioplasty was performed using Strattice™ or lightweight polypropylene (Ultrapro) mesh. Quality of life, pain, overall complication rate, and recurrence were measured. One hundred and seventy-two patients were randomized to Strattice™ (n = 84) or Ultrapro (n = 88). At 3 months postoperatively, there were no differences on the occurrence or type of wound events [RR: 0.98 (95 % CI 0.52–1.86, p = 0.69), Strattice™ (15 events) vs. Ultrapro (16 events)]. The mean level of impairment caused by the hernia, assessed by Activities Assessment Scale (AAS), significantly decreased postoperatively in both groups at 3 months (31 % Strattice™ and 37 % Ultrapro). Patients in the Strattice group reported significantly less postoperative pain during postoperative days 1 through 3 compared to Ultrapro patients. However, the amount of postoperative pain at 3 months, as assessed by the mean worst pain score on a visual analog scale and the Brief Pain Index, was similar between groups (95 % CI 1.0–29.3). No hernia recurrences were observed in either group. Strattice™ is safe and effective in repairing inguinal hernia, with comparable intra-operative and early postoperative morbidity to synthetic mesh. Long-term follow-up is necessary in order to know whether the clinical outcomes of Strattice are equivalent to standard synthetic mesh in patients undergoing Lichtenstein’s hernioplasty.

Microtubule-associated doublecortin and CaM kinase-like-1 (DCLK1) is a novel candidate marker for intestinal stem cells. The aim of our study was to assess DCLK1 immunoreactivity in colorectal carcinogenesis and its correlation with prognosis. DCLK1 immunostaining was performed in colorectal tissue from 71 patients, including 18 adenomatous polyps, 40 primary adenocarcinomas, and 14 metastatic lesions. Each case was evaluated by a combined scoring method based on the intensity of staining (score 0–3) and the percentage of tissue staining positive (score 0–3). Immunoexpression for DCLK1 was considered as positive when the combined score was 2–6 and negative with a score of 0–1. Overall, 14/18 (78%) of polyps, 30/40 (75%) of primary adenocarcinomas, and 7/14 (50%) of distant metastases were positive for DCLK1. In adenomatous polyps and primary cancer there was no association between DCLK1 staining score and tumor pathology. However, after curative colorectal cancer resection, patients whose tumor had a high (≥5) combined staining score had increased cancer-specific mortality compared to patients with low (0–4) staining score (hazard ratio 5.89; 95% confidence interval: 1.22–28.47; P = 0.027). We found that DCLK1 is frequently expressed in colorectal neoplasia and may be associated with poor prognosis. Further studies are necessary to validate the use of DCLK1 as a prognostic marker.