Endoscopic submucosal dissection in colorectal neoplasia performed with a waterjet system-assisted knife: higher en-bloc resection rate than conventional technique

BACKGROUND/AIMS

Colorectal endoscopic submucosal dissection (ESD) is burdened by its associated high risk of adverse events and long procedure time. Recently, a waterjet-assisted knife was introduced to simplify and speed up the procedure. The aim of this study was to evaluate the efficacy and safety of waterjet-assisted ESD (WESD) compared to that of the conventional ESD (CESD) technique.

METHODS

The charts of 254 consecutive patients who underwent colorectal ESD between January 2014 and February 2021 for colorectal neoplasms were analyzed. The primary outcome was the en-bloc resection rate. Secondary outcomes were complete and curative resection rates, the need to switch to a hybrid ESD, procedure speed, the adverse event rates, and the recurrence rates.

RESULTS

Approximately 174 neoplasias were considered, of which, 123 were removed by WESD and 51 by CESD. The en-bloc resection rate was higher in the WESD group (94.3% vs. 84.3%). Complete resection rates and curative resection rates were similar. The need to switch to a hybrid ESD was greater during CESD (39.2% vs. 13.8%). Procedure speed and adverse event rates were similar. During follow-up, one recurrence occurred after a WESD.

CONCLUSION

WESD allows a high rate of en-bloc resections and less frequently requires a rescue switch to the hybrid ESD compared to CESD.

Endoscopic submucosal dissection: Italian national survey on current practices, training and outcomes

BACKGROUND AND AIMS

Most of the evidence supporting endoscopic submucosal dissection (ESD) comes from Asia. European data are primarily reported by specialized referral centers and thus may not be representative of common European ESD practice. The aim of this study is to understand the current state of ESD practice across Italian endoscopy centers.

METHODS

All Italian endoscopists who were known to perform ESD were invited to complete a structured questionnaire including: operator features and competencies, ESD training details and clinical outcomes over a 2-year period.

RESULTS

Twenty-nine operators from 23 centers (69% response rate) completed the questionnaire: 18 (62%) were <50 years old; 7 (24%) were female; 16 (70%) were located in Northern Italy. Overall ESD volume was <40 cases in 9 (31%) operators, 40-80 in 8 (27.5%), 80-150 in 4 (13.8%) and >150 in 8 (27.5%). Colorectal ESD was predominant for operators with an experience >80 cases. En-bloc resection rates ranged from 77.2 to 97.2% depending on the anatomic location with an R0 resection rate range of 75.3-93.6%. ESD perforation rates in the colon and rectum were significantly lower when experience was >150 compared to 80-150 cases (p < 0.0001 and p = 0.006 for colon and rectum, respectively).

CONCLUSION

ESD in Italy is performed by a significant number of operators. Overall, Italian endoscopists performing ESD have achieved a good competence level. However, there is much variability in training protocols, initial supervision of procedures, practice settings, case mix and procedural volume/year that are likely responsible for some of the suboptimal resectional outcomes and increased perforation risk, mainly in the colon. Standardized training programs, practice parameters and auditing of outcomes are required.

Evolution of Ventricular Energetics in the Different Stages of Palliation of Hypoplastic Left Heart Syndrome: A Retrospective Clinical Study

Hyperplastic left heart syndrome (HLHS) patients are palliated by creating a Fontan-type circulation passing from different surgical stages. The aim of this work is to describe the evolution of ventricular energetics parameters in HLHS patients during the different stages of palliation including the hybrid, the Norwood, the bidirectional Glenn (BDG), and the Fontan procedures. We conducted a retrospective clinical study enrolling all HLHS patients surgically treated with hybrid procedure and/or Norwood and/or BDG and/or Fontan operation from 2011 to 2016 collecting echocardiographic and hemodynamic data. Measured data were used to calculate energetic variables such as ventricular elastances, external and internal work, ventriculo-arterial coupling and cardiac mechanical efficiency. From 2010 to 2016, a total of 29 HLHS patients undergoing cardiac catheterization after hybrid (n = 7) or Norwood (n = 6) or Glenn (n = 8) or Fontan (n = 8) procedure were retrospectively enrolled. Ventricular volumes were significantly higher in the Norwood circulation than in the hybrid circulation (p = 0.03) with a progressive decrement from the first stage to the Fontan completion. Ventricular elastances were lower in the Norwood circulation than in the hybrid circulation and progressively increased passing from the first stage to the Fontan completion. The arterial elastance and Rtot increased in the Fontan circulation. The ventricular work progressively increased. Finally, the ventricular efficiency improves passing from the first to the last stage of palliation. The use of ventricular energetic parameters could lead to a more complete evaluation of such complex patients to better understand their adaptation to different pathophysiological conditions.

Endoscopic submucosal dissection of gastric superficial neoplastic lesions: a single Western center experience

Background

Endoscopic submucosal dissection (ESD) allows "en bloc" resection of superficial gastric lesions.

Objective

The aim of this study is to report "en bloc" resection rate, procedure results, post resection features, analysis of complications, and relapses at mid-long term follow-up on an Italian center case series of patients with superficial gastric neoplastic lesions treated with ESD.

Methods

This is a retrospective evaluation of a prospectively collected series of patients diagnosed with gastric superficial lesions who underwent ESD between November 2007 and May 2015. The analysis included demographic, clinical, endoscopic, and histological data. In detail, the following features were analyzed: (1) "en bloc" resection rate; (2) R0, R1, and RX rate; (3) complication rate; and (4) neoplastic recurrence during follow-up. A comparison was performed between lesions treated according to standard and to extended criteria.

Results

In the analysis, therefore, 70 superficial lesions and 70 endoscopic procedures were considered.Overall, 53 (76%) procedures were performed according to the extended-ESD criteria. The remaining 17 (24%) cases were performed according to standard criteria. In 68/70 (97%) procedures "en bloc" resection was successful. Forty-four (65.6%) patients had a R0 resection, while 15 (22%) patients had a R1 and the remaining 8 (12.4%) patients were RX. Two patients (2.8%) experienced a major complication. Overall, 7 patients (10.4%) required surgery: in two cases because of local recurrence, in one case for an intraprocedural complication not amenable to endoscopic treatment, in three patients with R1 vertical margins, and in the last patient because of an aggressive pathology (i.e. signet ring cell adenocarcinoma). The mean follow-up of patients with neoplastic lesions was 36.6 ± 13.1 months.

Conclusion

ESD for early gastric cancer is a safe and effective technique when performed by experienced Endoscopists also in Western setting. When comparing the outcomes of the ESD in patients with standard and extended indication there is no significant difference in terms of complete resection, complications and local recurrence rates. Larger Western studies are needed to clearly define the role and the outcomes of ESD in regions at low incidence for gastric neoplasia.

Evaluation of Clensia®, a new low-volume PEG bowel preparation in colonoscopy: Multicentre randomized controlled trial versus 4L PEG

BACKGROUND

Success of colonoscopy is linked to the adequacy of bowel cleansing. Polyethylene glycol 4L (PEG 4L) solutions are widely used for colonic cleansing but with limitations concerning tolerability and acceptability.

AIM

To demonstrate the equivalence of a new low-volume PEG containing citrates and simeticone (Clensia) versus a standard PEG 4L.

METHODS

In this, multicentre, randomised, observer-blind trial, patients received either Clensia 2L or PEG 4L solution. Primary endpoint was the proportion of patients with colon cleansing evaluated as excellent or good.

RESULTS

422 patients received Clensia (n=213) or PEG 4L (n=209). Rate of excellent/good bowel cleansing was 73.6% and 72.3% in Clensia and PEG 4L group respectively. Clensia was demonstrated to be equivalent to PEG 4L. No SAEs were observed. Clensia showed better gastrointestinal tolerability (37.0% vs 25.4%). The acceptability was significantly better with Clensia in terms of proportion of subjects who felt no distress (Clensia 72.8% vs PEG 4L 63%, P=0.0314) and willingness-to-repeat (93.9% vs 82.2%, P=0.0002). The rate of optimal compliance was similar with both formulations (91.1% for Clensia vs 90.9% for PEG 4L, P=0.9388).

CONCLUSIONS

The low-volume Clensia is equally effective and safe in bowel cleansing compared to the standard PEG 4L, with better gastrointestinal tolerability and acceptability.

Usefulness of virtual chromoendoscopy in the evaluation of subtle small bowel ulcerative lesions by endoscopists with no experience in videocapsule

BACKGROUND AND STUDY AIMS

In videocapsule endoscopy examination (VCE), subtle variations in mucosal hue or pattern such as those seen in ulcerations can be difficult to detect, depending on the experience of the reader. Our aim was to test whether virtual chromoendoscopy (VC) techniques, designed to enhance the contrast between the lesion and the normal mucosa, could improve the characterization of ulcerative mucosal lesions.

PATIENTS AND METHODS

Fifteen trainees or young gastroenterologists with no experience in VCE were randomly assigned to evaluate 250 true ulcerative and 100 false ulcerative, difficult-to-interpret small bowel lesions, initially as white light images (WLI) and then, in a second round, with the addition of one VC setting or again as WLI, labeling them as real lesions or artifacts.

RESULTS

On the overall image evaluation, an improvement in lesion characterization was observed by adding any chromoendoscopy setting, especially Blue mode and FICE 1, with increases in accuracy of 13 % [95 %CI 0.8, 25.3] and 7.1 % [95 %CI - 17.0, 31.3], respectively. However, when only false ulcerative images were considered, with the same presets (Blue mode and FICE 1), there was a loss in accuracy of 10.7 % [95 %CI - 10.9, 32.3] and 7.3 % [95 %CI - 1.3, 16.0], respectively. The interobserver agreement was poor for both readings.

CONCLUSIONS

VC helps beginner VCE readers correctly categorize difficult-to-interpret small bowel mucosal ulcerative lesions. However, false lesions tend to be misinterpreted as true ulcerative with the same presets. Therefore care is advised in using VC especially under poor bowel preparation.

Modulation of the gut microbiota composition by rifaximin in non-constipated irritable bowel syndrome patients: a molecular approach

Rifaximin, with its low systemic absorption, may represent a treatment of choice for irritable bowel syndrome (IBS), mainly due to its ability to act on IBS pathogenesis, through the influence on gut microbiota. The aim of the present study was to assess, by biomolecular tools, the rifaximin active modulation exerted on gut microbiota of non-constipated IBS patients. Fifteen non-constipated IBS subjects were treated with 550 mg rifaximin three times a day for 14 days. Stool samples were collected before starting the treatment, at the end of it, and after a 6-week washout period. Real-time polymerase chain reaction, denaturing gradient gel electrophoresis, and next-generation sequencing were applied to all the samples to verify and quantify possible microbial fluctuations. Rifaximin treatment did not affect the overall composition of the microbiota of the treated subjects, inducing fluctuations in few bacterial groups, balanced by the replacement of homologs or complementary bacterial groups. Rifaximin appeared to influence mainly potentially detrimental bacteria, such as Clostridium, but increasing the presence of some species, such as Faecalibacterium prausnitzii. A decrease in the Firmicutes/Bacteroidetes ratio after 14 days of treatment and bacterial profiles with higher biodiversity were observed during the follow-up compared to baseline. Rifaximin treatment, although effective on IBS symptom relief and normalization of lactulose breath test, did not induce dramatic shifts in the microbiota composition of the subjects, stimulating microbial reorganization in some populations toward a more diverse composition. It was not possible to speculate on differences of fecal microbiota modification between responders vs nonresponders and to correlate the quali-/quantitative modification of upper gastrointestinal microbiota and clinical response.

Circulating hematopoietic stem cells and putative intestinal stem cells in coeliac disease

Background

The intestinal stem cells (ISC) modulation and the role of circulating hematopoietic stem cells (HSC) in coeliac disease (CD) are poorly understood. Our aim was to investigate the longitudinal modifications in peripheral blood HSC traffic and putative ISC density induced by gluten-free diet (GFD) in CD.

Methods

Thirty-one CD patients and 7 controls were enrolled. Circulating CD133⁺ and CD34⁺ HSC were measured by flow cytometry, at enrolment and after 7 days and 1, 3, 6, 12, and 24 months of GFD. Endoscopy was performed at diagnosis and repeated at 6, 12, and 24 months following GFD. We used the Marsh-Oberhuber score to evaluate the histological severity of duodenal damage; immunohistochemistry was employed to measure the intraepithelial lymphoid infiltrate (IEL, CD3⁺ lymphoid cells) and the putative ISC compartment (CD133⁺ and Lgr5⁺ epithelial cells).

Results

At enrolment, circulating HSCs were significantly increased in CD patients and they further augmented during the first week of GFD, but progressively decreased afterwards. CD patients presented with villous atrophy, abundant IEL and rare ISC residing at the crypt base. Upon GFD, IEL progressively decreased, while ISC density increased, peaking at 12 months. After 24 months of GFD, all patients were asymptomatic and their duodenal mucosa was macroscopically and histologically normal.

Conclusions

In active CD patients, the ISC niche is depleted and there is an increased traffic of circulating HSC versus non-coeliac subjects. GFD induces a precocious mobilization of circulating HSC, which is followed by the expansion of the local ISC compartment, leading to mucosal healing and clinical remission.

Rifaximin for the treatment of diarrhoea-predominant irritable bowel syndrome

INTRODUCTION

Rifaximin is a non-absorbable, semisynthetic antibiotic that acts as an inhibitor of bacterial RNA synthesis, with a broad spectrum of antibacterial activity. Due to its poor absorption, rifaximin has an increased exposure to the intestine, thus it is suitable for the treatment of many gastrointestinal (GI) diseases. In irritable bowel syndrome (IBS) pathogenesis, gut microbiota impairment may play a major role. The possibility of modulating intestinal bacteria using antibiotics, in particular, rifaximin, has been demonstrated to improve IBS symptoms in non-constipation subtypes of IBS.

AREAS COVERED

We reviewed the use of rifaximin in diarrhoea-predominant IBS, focusing on its pharmacokinetic characteristics, its absorption in GI disease, its lack of interaction with other drugs and its new extended release formulation.

EXPERT OPINION

Rifaximin, with its low systemic absorption and no clinically significant interactions with other drugs, may represent a treatment of choice for IBS, mainly due to its ability to act on IBS pathogenesis, through the modulation of gut microbiota. Further studies to analyse the effect of rifaximin treatment on the composition of faecal microbiota are warranted. In particular, they need to evaluate whether resistant bacterial strains are selected and whether they are still present in the faecal sample even a long time after therapy.

Colon capsule endoscopy: What we know and what we would like to know

Colonoscopy is usually perceived as an invasive and potentially painful procedure, being also affected by a small, but definite, risk of major complications (cardiopulmonary complications, perforation, hemorrhage) and even mortality. To improve both acceptability and safety, PillCam Colon Capsule Endoscopy (CCE) (Given Imaging Ltd, Yoqneam, Israel) has been developed. CCE represents a non-invasive technique that is able to explore the colon without sedation and air insufflation. The Second Generation of Colon Capsule Endoscopy (PillCam Colon 2) (CCE-2) was proven to be an accurate tool to detect colonic neoplastic lesions when used in average risk individuals. To date, the evidence supports the use of CCE-2 in case of colonoscopy failure, in patients unwilling to perform colonoscopy and when colonoscopy is contraindicated. Other potential applications, such as colorectal cancer screening or diagnostic surveillance of inflammatory bowel disease need to be clarified. In this paper, the current “state of the art”, potential application of CCE and future needs are evaluated.

Methane intestinal production and poor metabolic control in type I diabetes complicated by autonomic neuropathy

AIM

At the state of art it's unknown the correlation between diabetes and lower gastrointestinal disorders. Some studies show a significantly higher prevalence of small intestinal bacterial overgrowth in patients with type I diabetes in particular complicated by autonomic neuropathy. No data exists about gastrointestinal methane production in patients with diabetes and autonomic diabetic neuropathy. The aim of this paper was to evaluate the correlation of small intestinal bacterial overgrowth and gastrointestinal methane production with metabolic control and daily insulin requirements in patients with type 1 diabetes and. autonomic diabetic neuropathy.

METHODS

Thirty subjects with type 1 diabetes and autonomic diabetic neuropathy were underwent hydrogen and methane lactulose breath test (LBT) to evaluate the presence of small intestinal bacterial overgrowth (double peak of hydrogen) and methane production. The metabolic control was evaluated through the glycated hemoglobin and the daily insulin requirement (calculated as ratio between total insulin units in a day and body weight). Methane producers were treated with metronidazole (500 mg bid for 10 days) and perform a LBT 8 weeks after the end of therapy

RESULTS

Eight over thirty patients (26.6%) met the diagnostic criteria for small intestinal bacterial overgrowth. 11/30 patients (36%) were methane-producers (mean baseline value 16.37 ± 13.01 ppm; mean peak 26.62 ± 11.41 ppm); interestingly this subset of patients showed a worse glycemic control (mean HbA1c 8.16 ± 0.9% vs. 7.49 ± 0.8%, P<0.05). After metronidazole therapy 7/11 (63.3%) reduced CH4 production and they showed a mean HbA1c significantly lower than corresponding value before antibiotic therapy (7.63 ± 0.7% vs. 8.25 ± 0.8%).

CONCLUSION

Our study showed for the first time a possible role of CH4 production in metabolic control. In particular, the most interesting data is that an increased values of HbA1c seems to be related to a gut CH4 production as confirmed by its significant improvement after eradication therapy. We are not yet able to determine whether poor glycemic control is the cause or the consequence of the selection of methanogenic flora.

Nickel free-diet enhances the Helicobacter pylori eradication rate: a pilot study

BACKGROUND

The Helicobacter pylori eradication rate with standard triple therapy is very low. H. pylori is known to require the nickel-containing metalloenzymes urease and NiFe-hydrogenase to survive at the low pH environment in the stomach.

AIM

To compare the H. pylori eradication rate of a nickel free-diet associated with standard triple therapy and standard triple therapy alone as the first-line regimen.

METHODS

Fifty-two sex- and age-matched patients at the first diagnosis of H. pylori infection were randomized 1:1 into two different therapeutic schemes: (1) standard LCA (26 patients): lansoprazole 15 mg bid, clarithromycin 500 mg bid and amoxicillin 1,000 mg bid for 7 days with a common diet; (2) standard LCA plus a nickel free-diet (NFD-LCA) (26 patients). Patients followed 30 days of a nickel-free diet plus a week of lansoprazole 15 mg bid, clarithromycin 500 mg bid and amoxicillin 1,000 mg bid starting from day 15 of the diet.

RESULTS

All patients completed the study. A significantly higher eradication rate was observed in the NFD-LCA group (22/26) versus LCA group (12/26) (p < 0.01). Only a few patients (9 of 52) reported the occurrence of mild therapy-related side effects, without any significant differences between the two groups.

CONCLUSIONS

The addition of a nickel-free diet to standard triple therapy significantly increases the H. pylori eradication rate. The reduction of H. pylori urease activity due to the nickel-free diet could expose the bacterium to gastric acid and increase H. pylori's susceptibility to amoxicillin. Further studies are necessary to confirm this preliminary result.

The role of small intestinal bacterial overgrowth in Parkinson's disease

Parkinson's disease is associated with gastrointestinal motility abnormalities favoring the occurrence of local infections. The aim of this study was to investigate whether small intestinal bacterial overgrowth contributes to the pathophysiology of motor fluctuations. Thirty-three patients and 30 controls underwent glucose, lactulose, and urea breath tests to detect small intestinal bacterial overgrowth and Helicobacter pylori infection. Patients also underwent ultrasonography to evaluate gastric emptying. The clinical status and plasma concentration of levodopa were assessed after an acute drug challenge with a standard dose of levodopa, and motor complications were assessed by Unified Parkinson's Disease Rating Scale-IV and by 1-week diaries of motor conditions. Patients with small intestinal bacterial overgrowth were treated with rifaximin and were clinically and instrumentally reevaluated 1 and 6 months later. The prevalence of small intestinal bacterial overgrowth was significantly higher in patients than in controls (54.5% vs. 20.0%; P = .01), whereas the prevalence of Helicobacter pylori infection was not (33.3% vs. 26.7%). Compared with patients without any infection, the prevalence of unpredictable fluctuations was significantly higher in patients with both infections (8.3% vs. 87.5%; P = .008). Gastric half-emptying time was significantly longer in patients than in healthy controls but did not differ in patients based on their infective status. Compared with patients without isolated small intestinal bacterial overgrowth, patients with isolated small intestinal bacterial overgrowth had longer off time daily and more episodes of delayed-on and no-on. The eradication of small intestinal bacterial overgrowth resulted in improvement in motor fluctuations without affecting the pharmacokinetics of levodopa. The relapse rate of small intestinal bacterial overgrowth at 6 months was 43%. © 2013 Movement Disorder Society.

Single-step multimodal locoregional treatment for unresectable hepatocellular carcinoma: balloon-occluded percutaneous radiofrequency thermal ablation (BO-RFA) plus transcatheter arterial chemoembolization (TACE)

PURPOSE

This study was undertaken to evaluate the feasibility, safety and efficacy of a new combined single-step therapy in patients with unresectable multinodular unilobar hepatocellular carcinoma (HCC), with at least one lesion >3 cm, with balloon-occluded radiofrequency ablation (BO-RFA) plus transcatheter arterial chemoembolization (TACE) of the main lesion and TACE of the other lesions. The second purpose of our study was to compare the initial effects in terms of tumour necrosis of this new combined therapy with those obtained in a matched population treated with TACE alone in a singlestep treatment in our centre in the previous year.

METHODS AND MATERIALS

This pilot study was approved by the institutional review board, and informed consent was obtained from all patients. Ten consecutive patients with multinodular (two to six nodules) unilobar unresectable HCC and with a main target lesion >3 cm (range, 3.5-6 cm) not suitable for curative therapy were enrolled in our single-centre multidisciplinary pilot study. The schedule consisted of percutaneous RFA (single 3-cm monopolar needle insertion) of the target lesion during occlusion of the hepatic artery supplying the tumour, followed by selective TACE, plus lobar TACE for other lesions (450-mg carboplatin and lipiodol plus temporary embolisation with SPONGOSTAN). Adverse events and intra- and periprocedural complications were clinically assessed. Early local efficacy was evaluated on 1-month follow-up multiphasic computed tomography (CT) on the basis of the Modified Response Evaluation Criteria in Solid Tumors (m-RECIST). A separate evaluation of target lesions in terms of enhancement, necrotic diameter and presence and distribution of lipiodol uptake was also performed.

RESULTS

No major complications occurred. Overall technical success, defined as complete devascularisation of all nodules during the arterial phase, was achieved in seven of 10 patients, with three cases of partial response (persistence of small hypervascular nodules). When considering only target lesions, technical success was obtained in all patients, with a nonenhancing area corresponding in shape to the previously identified HCC (necrotic diameter, 3.5-5 cm) and with circumferential peripheral lipiodol uptake (safety margin) of at least 0.5 cm (0.5-1.3cm).

CONCLUSIONS

TACE and BO-RFA, plus TACE in a singlestep approach seems to be a safe and effective combined therapy for treating advanced, unresectable HCC lesions, allowing a high rate of complete local response to be achieved in large lesions also.

From small nodule to overt HCC: a multistep process of carcinogenesis as seen during surveillance

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related death in the world. Despite many diagnostic and therapeutic tools are now available to improve survival and reduce its recurrence, prognosis is closely conditioned by the time of diagnosis. Surveillance and early diagnosis are crucial for a successful therapy. We report a clinical case from the HCC archive of the Hepatocatt meetings held in Ge-melli Hospital (Catholic University of Rome). The case describes a tumor progression in a multistep process from a small liver nodule to overt HCC and its management by a multidisciplinary team.

Role of gut microbiota in food tolerance and allergies

Alterations of commensal flora may cause various gastrointestinal and extraintestinal diseases, including food intolerances and food allergies. According to the 'microflora hypothesis', alterations in the composition of gut microbiota in industrialized countries have disturbed the mechanisms of mucosal immune tolerance. Over the past few years several studies have looked for a role for probiotics in the treatment of food allergies with promising results.

Gut microbiota and obesity

Intestinal epithelium, mucosal immune system, and bacterial flora represent a morpho-functional system on dynamic balance responsible for the intestinal metabolic and trophic functions, and the regulation of mucosal and systemic host's immunity. Obesity is a pathological condition affecting a growing number of people especially in the Western countries resulting from the failure of the organism's energetic balance based on the perfect equality of income, waste, and storage. Recent evidences explain the mechanisms for the microbial regulation of the host's metabolism both in health and disease. In particular, animal studies have explained how quali-/quantitative changes in microflora composition are able to affect the absorption of the nutrients and the energy distribution. Antibiotics, prebiotics, probiotics, and symbiotics are the instruments utilized in the current clinical practice to modulate the intestinal bacterial flora in man both in health and pathologic conditions with promising preliminary results on prevention and therapy of obesity and related metabolic diseases.

Stem cell-based therapies for liver diseases: state of the art and new perspectives

Millions of patients worldwide suffer from end-stage liver pathologies, whose only curative therapy is liver transplantation (OLT). Given the donor organ shortage, alternatives to OLT have been evaluated, including cell therapies. Hepatocyte transplantation has been attempted to cure metabolic liver disorders and end-stage liver diseases. The evaluation of its efficacy is complicated by the shortage of human hepatocytes and their difficult expansion and cryopreservation. Recent advances in cell biology have led to the concept of "regenerative medicine", based on the therapeutic potential of stem cells (SCs). Different types of SCs are theoretically eligible for liver cell replacement. These include embryonic and fetal SCs, induced pluripotent cells, annex SCs, endogenous liver SCs, and extrahepatic adult SCs. Aim of this paper is to critically analyze the possible sources of SCs suitable for liver repopulation and the results of the clinical trials that have been published until now.

Small bowel nonendocrine neoplasms: current concepts and novel perspectives

Although small bowel nonendocrine neoplasms are rare, their incidence has increased dramatically over the past 30 years. Small bowel malignacies can be classified depending upon their cellular origin into four principal histotypes: carcinoid tumors, adenocarcinomas, lymphomas and mesenchymal tumors. Until a few years ago, the treatment of small bowel tumors had remained relatively unchanged, with little progress in the development of effective adjuvant therapies and in the improvement of long-term survival over time. Recently, the growing interest in the understanding of the mechanisms underlying carcinogenesis has offered novel insights for the diagnosis and therapy of small bowel tumors. This review summarizes the state-of-the-art of small bowel nonendocrine tumors and the recent advancements in the knowledge of their molecular pathogenesis and cellular origin, with particular emphasis on stem cell research field.

Stem cell-based therapy in gastroenterology and hepatology

Protagonists of a new scientific era, stem cells are promising tools on which regenerative medicine relies for the treatment of human pathologies. Stem cells can be obtained from various sources, including embryos, fetal tissues, umbilical cord blood, and also terminally differentiated organs. Once forced to expand and differentiate into functional progenies, stem cells may become suitable for cell replacement and tissue engineering. The manipulation and/or stimulation of adult stem cells seems to be particularly promising, as it could improve the endogenous regenerative potential without risks of rejection and overcome the ethical and political issues related to embryonic stem cell research. Stem cells are already leaving the bench and reaching the bedside, despite an incomplete knowledge of the genetic control program driving their fate and plasticity. In gastroenterology and hepatology, the first attempts to translate stem cell basic research into novel therapeutic strategies have been made for the treatment of several disorders, such as inflammatory bowel diseases, diabetes mellitus, celiachy and acute or chronic hepatopaties. Nonetheless, critical aspects need to be further addressed, including the long-term safety, tolerability and efficacy of cell-based treatments, as well as their carcinogenic potential. Aim of this review is to summarize the state-of-the-arts on gastrointestinal and hepatic stem cells and on stem cell-based therapies in gastroenterology and hepatology, highlighting both the benefits and the potential risks of these new tools for the treatment and prevention of human diseases.