Gianfranco Cocorullo

CD44v6 is a marker of constitutive and reprogrammed cancer stem cells driving colon cancer metastasis.

Cancer stem cells drive tumor formation and metastasis, but how they acquire metastatic traits is not well understood. Here, we show that all colorectal cancer stem cells (CR-CSCs) express CD44v6, which is required for their migration and generation of metastatic tumors. CD44v6 expression is low in primary tumors but demarcated clonogenic CR-CSC populations. Cytokines hepatocyte growth factor (HGF), osteopontin (OPN), and stromal-derived factor 1α (SDF-1), secreted from tumor associated cells, increase CD44v6 expression in CR-CSCs by activating the Wnt/β-catenin pathway, which promotes migration and metastasis. CD44v6(-) progenitor cells do not give rise to metastatic lesions but, when treated with cytokines, acquire CD44v6 expression and metastatic capacity. Importantly, phosphatidylinositol 3-kinase (PI3K) inhibition selectively killed CD44v6 CR-CSCs and reduced metastatic growth. In patient cohorts, low levels of CD44v6 predict increased probability of survival. Thus, the metastatic process in colorectal cancer is initiated by CSCs through the expression of CD44v6, which is both a functional biomarker and therapeutic target.

KPC - 3 Klebsiella pneumoniae ST258 clone infection in postoperative abdominal surgery patients in an intensive care setting: analysis of a case series of 30 patients.

BackgroundAbdominal surgery carries significant morbidity and mortality, which is in turn associated with an enormous use of healthcare resources. We describe the clinical course of 30 Intensive Care Unit (ICU) patients who underwent abdominal surgery and showed severe infections caused by Klebsiella pneumoniae sequence type (ST) 258 producing K. pneumoniae carbapenemase (KPC-Kp). The aim was to evaluate risk factors for mortality and the impact of a combination therapy of colistin plus recommended regimen or higher dosage of tigecycline.MethodsA prospective assessment of severe monomicrobial KPC-Kp infections occurring after open abdominal surgery carried out from August 2011 to August 2012 in the same hospital by different surgical teams is presented. Clinical and surgical characteristics, microbiological and surveillance data, factors associated with mortality and treatment regimens were analyzed. A combination regimen of colistin with tigecycline was used. A high dose of tigecycline was administered according to intra-abdominal abscess severity and MICs for tigecycline.ResultsThe mean age of the patients was 56.6 ± 15 and their APACHE score on admission averaged 22.72. Twenty out of 30 patients came from the surgical emergency unit. Fifteen patients showed intra-abdominal abscess, eight anastomotic leakage, four surgical site infection (SSI) and three peritonitis. The overall crude ICU mortality rate was 40% (12 out of 30 patients). Twelve of the 30 patients were started on a combination treatment of high-dose tigecycline and intravenous colistin. A significantly lower mortality rate was observed among those patients compared to patients treated with approved dose of tigecycline plus colistin. No adverse events were reported with high doses of tigecycline.ConclusionsCritically-ill surgical patients are prone to severe post-surgical infectious complications caused by KPC-Kp. Timely microbiological diagnosis and optimizing antibiotic dosing regimens are essential to prevent worse outcomes. Further studies and well-controlled clinical trials are needed to define the optimal treatment of infections by KPC-Kp and, more generally, carbapenem-resistant bacteria.

Subcutaneous emphysema, pneumomediastinum and pneumoperitoneum after diagnostic colonoscopy for ulcerative colitis: a rare but possible complication in patients with multiple risk factors

Dear Editor: Colonoscopy is regarded as a safe procedure, but complications may occur. The most dreaded are perforation and massive bleeding of the colon. The incidence of perforation is low but, despite increased experience with the procedure, it remains unchanged over time and in a large population study ranges from 0.6 to 1 per 1.000 procedures, depending on the centre and the data source. Few studies have assessed risk factors for colonoscopy-related bleeding and perforation. Gatto et al. have reported that there was a significant trend in the incidence of perforation with increasing age, people aged 75 years or older having a fourfold risk as compared to those aged 65–69 years; same results were obtained by Levin et al. in a series of more than 16.000 colonoscopies. The risk for adverse events has been also associated with comorbidity: diabetes, stroke, cardiovascular disease, chronic obstructive pulmonary disease. Moreover, risk factors for the development of perforations are pre-existing diseases of the colon (polyposis, inflammatory bowel disease, diverticula, strictures, etc.) and conditions related to the procedure itself, bowel cleansing or sedation. An estimated 50% to 100% of patients with a colonic perforation after colonoscopy require a laparotomy for closure of the perforation, with associated major postoperative morbidity and mortality reaching 39% and 25%, respectively. An 80-year-old man with a 6-months history of diarrhoea (six motions/day) with mucus and, occasionally, blood was admitted to our department. Ulcerative colitis (UC) and diverticula had been recently diagnosed, but he did not respond to therapy. Past medical history revealed a cerebrovascular accident and coronary heart disease which requested aortocoronary bypass; for this reason he was on ticlopidine. We carried out colonoscopy according to the standard procedures. About 1 h after endoscopy the patient developed progressive facial and neck swelling, without any pain, dyspnea or stridor. On examination, vital parameters were normal. A clear crepitus was palpated in the head and neck, compatible with subcutaneous emphysema, and the chest was normal. The abdomen was tympanic but not tender, with normal peristalsis. Laboratory tests were normal. X-rays and a total body computed tomography were carried out and showed massive air leakage, with free air intraand retroperitoneal, mediastinal air with limited pneumomediastinum and subcutaneous emphysema extending to the zygoma. The patient was managed conservatively with intravenous fluids and antibiotics (ceftriaxone). Twenty-four hours after onset of symptoms, he developed abdominal pain, fever (38°C) and mild leukocytosis (13.760/mmc); and he was transferred to surgical department. He was submitted to explorative laparoscopy which evidentiated a perforation of the caecum with exudative material in the peritoneum and air trapped into the retroperitoneum forming multiple bubbles. Right hemicolectomy with antiperistaltic ileocolonic anastomosis was carried out. The postoperative course M. Cappello (*) :C. Randazzo : S. Peralta Sezione e U.O.C. di Gastroenterologia, Dipartimento Biomedico di Medicina Interna e Specialistica, Universita di Palermo, Piazza Delle Cliniche 2, 90127 Palermo, Italy e-mail: cmarica@tin.it

Monoclonal antibodies and antibody fragments: state of the art and future perspectives in the treatment of non-haematological tumors.

Introduction: The use of monoclonal antibodies is one of the strategies for targeting the specific key points of the main pathways of cancer growth and survival, but only a few antibodies have offered a clear clinical benefit in the treatment of non-haematological malignancies. Areas covered: This review summarizes the general properties of monoclonal antibodies, including structure, nomenclature and production techniques. The antibodies approved for use in clinical practice for the treatment of non-haematological tumors and those antibodies still being developed in this setting are briefly described. The types of antibody fragments are also reported. Expert opinion: Monoclonal antibodies were initially developed in order to avoid the cytotoxic effects of chemotherapy on healthy tissues. However antibodies have not yet replaced chemotherapy agents, since the combination of both kinds of drugs have usually appeared to achieve higher benefit compared with chemotherapy alone. The research for the development of new monoclonal antibodies aims to identify further targets and to provide innovative antibody constructs.

Use of Cepheid Xpert Carba-R® for Rapid Detection of Carbapenemase-Producing Bacteria in Abdominal Septic Patients Admitted to Intensive Care Unit

Early institution of effective antibiotic therapy and source control are pivotal to improve survival of abdominal septic patients. Xpert® Carba-R is a real time polymerase chain reaction assay for rapid detection and differentiation of five genes (blaKPC, blaVIM, blaOXA-48, blaIMP-1, blaNDM) responsible for carbapenem resistance. We performed an observational study investigating the clinical usefulness and applicability of Xpert® Carba-R to detect carbapenem resistance in abdominal septic patients admitted to intensive care unit. We compared the results of Xpert® Carba-R with standard microbiological culture. We collected a set of two rectal/stomia swabs and two swabs from abdominal drainage fluid for each patient. We included 20 patients for a total of 45 comparisons between the two methods. In our clinical setting, the overall performance of Xpert® Carba-R for detection of carbapenem resistance in the presence of genes detectable and non-detectable by the method was: sensitivity 50% (95% CI 24.6–75.3); specificity 93.1% (95% CI 77.2–99.1); positive predictive value (PPV) 80% (95% CI 44.4–97.5); negative predictive value (NPV) 77.1% (95% CI 56.9–89.6). The inter-rater agreement was 0.47 (SE 0.14; 95% CI 0.20–0.74). When considering the only 5 mechanisms of resistance detected by both methods, the overall diagnostic performance was: sensitivity 100% (95% CI 69.1–100), specificity 94.2 (95% CI 80.8–99.3), PPV 83.3 (95% CI 59.6–97.9) and NPV 100% (95% CI 89.4–100). The inter-rater agreement was 0.88 (SE 0.08; 95% CI 0.71–1). Xpert® Carba-R may be considered an additional diagnostic tool for early diagnosis of carbapenem resistance in abdominal septic patients. Clinicians should be aware of their epidemiology before its introduction in the diagnostic protocol of their intensive care units.

Surgical pathology and the diagnosis of invasive visceral yeast infection: two case reports and literature review

Invasive mycoses are life-threatening opportunistic infections that have recently emerged as a cause of morbidity and mortality following general and gastrointestinal surgery.Candida species are the main fungal strains of gut flora. Gastrointestinal tract surgery might lead to mucosal disruption and cause Candida spp. to disseminate in the bloodstream.Here we report and discuss the peculiar clinical and morphological presentation of two cases of gastrointestinal Candida albicans lesions in patients who underwent abdominal surgery.Although in the majority of cases reported in the literature, diagnosis was made on the basis of microbiological criteria, we suggest that morphological features of fungi in histological sections of appropriate surgical specimens could help to detect the degree of yeast colonization and identify patients at risk of developing severe abdominal Candida infection.Better prevention and early antifungal treatments are highlighted, and relevant scientific literature is reviewed.

Biologic response of inguinal hernia prosthetics: a comparative study of conventional static meshes versus 3D dynamic implants.

Despite improvements in prosthetics and surgical techniques, the rate of complications following inguinal hernia repair remains high. Among these, discomfort and chronic pain have become a source of increasing concern among surgeons. Poor quality of tissue ingrowth, such as thin scar plates or shrinking scars-typical results with conventional static implants and plugs-may contribute to these adverse events. Recently, a new type of 3D dynamically responsive implant was introduced to the market. This device, designed to be placed fixation-free, seems to induce ingrowth of viable and structured tissue instead of regressive fibrotic scarring. To elucidate the differences in biologic response between the conventional static meshes and this 3D dynamically responsive implant, a histological comparison was planned. The aim of this study was to determine the quality of tissue incorporation in both types of implants excised after short, medium, and long periods post-implantation. The results showed large differences in the biologic responses between the two implant types. Histologically, the 3D dynamic implant showed development of tissue elements more similar to natural abdominal wall structures, such as the ingrowth of loose and well-hydrated connective tissue, well-formed vascular structures, elastic fibers, and mature nerves, with negligible or absent inflammatory response. All these characteristics were completely absent in the conventional static implants, where a persistent inflammatory reaction was associated with thin, hardened, and shrunken fibrotic scar formation. Consequently, as herniation is a degenerative process, the 3D dynamic implants, which induce regeneration of the typical groin components, seem to address its pathogenesis.

Histological findings in direct inguinal hernia : Investigating the histological changes of the herniated groin looking forward to ascertain the pathogenesis of hernia disease.

BackgroundThe study is focused on recognizing the histological changes of the structures close to and around the hernia opening in patients having direct inguinal hernia.MethodsIn 15 patients with primary bilateral direct inguinal hernia who underwent a Stoppa open posterior inguinal hernia repair, tissue specimens from the abdominal wall surrounding a direct hernia border were excised for histological examination. These findings in patients with direct inguinal hernia were compared with tissue specimens excised from the fossa inguinalis media of cadavers without hernia.ResultsSignificant degenerative modifications such as fibrohyaline degeneration and fatty substitution of the muscle fibers were seen in the biopsy samples. Inflammatory infiltration with lympho-histiocitary elements, artery sub-occlusion and vascular congestion were also constantly identified. Noteworthy injuries of the nervous structures such as edema, degenerative fibrosis and atrophy were also detected. No comparable tissue damage was witnessed in the control samples.ConclusionPresence of inflammatory infiltration, vascular damage and regressive nerve lesions, as well as fibrohyaline degeneration and fatty dystrophy of the muscle fibers are the features seen within the examined structures surrounding the direct hernia opening. These findings could represent a reason for a structural and functional weakening of the inguinal region. Consequently, the described results lead the authors to depict these changes as a plausible cause of direct inguinal hernia protrusion.

Current advances in γδ T cell-based tumor immunotherapy

γδ T cells are a minor population (~5%) of CD3 T cells in the peripheral blood, but abound in other anatomic sites such as the intestine or the skin. There are two major subsets of γδ T cells: those that express Vδ1 gene, paired with different Vγ elements, abound in the intestine and the skin, and recognize the major histocompatibility complex (MHC) class I-related molecules such as MHC class I-related molecule A, MHC class I-related molecule B, and UL16-binding protein expressed on many stressed and tumor cells. Conversely, γδ T cells expressing the Vδ2 gene paired with the Vγ9 chain are the predominant (50–90%) γδ T cell population in the peripheral blood and recognize phosphoantigens (PAgs) derived from the mevalonate pathway of mammalian cells, which is highly active upon infection or tumor transformation. Aminobisphosphonates (n-BPs), which inhibit farnesyl pyrophosphate synthase, a downstream enzyme of the mevalonate pathway, cause accumulation of upstream PAgs and therefore promote γδ T cell activation. γδ T cells have distinctive features that justify their utilization in antitumor immunotherapy: they do not require MHC restriction and are less dependent that αβ T cells on co-stimulatory signals, produce cytokines with known antitumor effects as interferon-γ and tumor necrosis factor-α and display cytotoxic and antitumor activities in vitro and in mouse models in vivo. Thus, there is interest in the potential application of γδ T cells in tumor immunotherapy, and several small-sized clinical trials have been conducted of γδ T cell-based immunotherapy in different types of cancer after the application of PAgs or n-BPs plus interleukin-2 in vivo or after adoptive transfer of ex vivo-expanded γδ T cells, particularly the Vγ9Vδ2 subset. Results from clinical trials testing the efficacy of any of these two strategies have shown that γδ T cell-based therapy is safe, but long-term clinical results to date are inconsistent. In this review, we will discuss the major achievements and pitfalls of the γδ T cell-based immunotherapy of cancer.

Intra-abdominal Candida spp infection in acute abdomen in a quality assurance (QA)-certified academic setting

Aims To evaluate the contribution of light microscopy to detecting Candida spp infection in patients with complicated intra-abdominal infections (IAIs) admitted for acute abdomen to a quality assurance (QA)-certified surgical emergency ward. Methods We conducted a retrospective study (2008–2012) of 809 abdominal intraoperative or biopsy tissue specimens obtained from patients admitted with acute abdomen and microbiological samples positive for Candida spp. Demographic data, mortality, comorbidities, specimen type, microscopy results, special histological staining performed, antimicrobial therapy were collected and analysed. Any comments at the multidisciplinary team meeting was recorded in minutes of and approved. Results Sixty-six patients with complicated IAIs due to Candida spp were identified (39 male, 27 female, mean±SD age 75±20 years). Candida albicans was isolated in 35 cases and Candida non-albicans spp in 31 cases. Candida spp were isolated from blood in 50% of all selected microbiological specimens. Patients were stratified according to Candida spp (albicans vs non-albicans), underlying cancer disease and no previous antimicrobial administration, and a positive correlation with C. albicans isolation was found (p=0.009 and p=0.048, respectively). Out of 41 cases with microscopic evaluation, we identified yeast forms, pseudohyphae or both, indicative of Candida spp, in 23. Identification of Candida spp in histological specimens was higher in C. albicans cases than in C. non-albicans cases (73% vs 37.5%). Microscopy allowed prompt treatment of all patients. Conclusions Light microscopy still has great diagnostic significance, being a solid QA step. It provides rapid information and clues in patients who may harbour impaired defence mechanisms, concurrent chronic conditions and/or cancer.