Fabio Maria Vecchio

Increased intestinal permeability and tight junction alterations in nonalcoholic fatty liver disease

The role played by the gut in nonalcoholic fatty liver disease (NAFLD) is still a matter of debate, although animal and human studies suggest that gut‐derived endotoxin may be important. We investigated intestinal permeability in patients with NAFLD and evaluated the correlations between this phenomenon and the stage of the disease, the integrity of tight junctions within the small intestine, and prevalence of small intestinal bacterial overgrowth (SIBO). We examined 35 consecutive patients with biopsy‐proven NAFLD, 27 with untreated celiac disease (as a model of intestinal hyperpermeability) and 24 healthy volunteers. We assessed the presence of SIBO by glucose breath testing (GBT), intestinal permeability by means of urinary excretion of 51Cr‐ethylene diamine tetraacetate (51Cr‐EDTA) test, and the integrity of tight junctions within the gut by immunohistochemical analysis of zona occludens‐1 (ZO‐1) expression in duodenal biopsy specimens. Patients with NAFLD had significantly increased gut permeability (compared with healthy subjects; P < 0.001) and a higher prevalence of SIBO, although both were lower than in the untreated celiac patients. In patients with NAFLD, both gut permeability and the prevalence of SIBO correlated with the severity of steatosis but not with presence of NASH. Conclusions: Our results provide the first evidence that NAFLD in humans is associated with increased gut permeability and that this abnormality is related to the increased prevalence of SIBO in these patients. The increased permeability appears to be caused by disruption of intercellular tight junctions in the intestine, and it may play an important role in the pathogenesis of hepatic fat deposition. (HEPATOLOGY 2009.)

Accurate lymph-node detection in colorectal specimens resected for cancer is of prognostic significance.

PURPOSE: Lymph-node involvement is the most important prognostic factor in colorectal cancers. Many staging systems adopted node status as a parameter of tumor classification. However, the number of identified and positive glands varies across articles, depending on specimen examination. There is a consistent risk of substaging tumors and undertreating patients. Aim of this study was to investigate the prognostic significance of different pathologic methods. METHODS: Eight hundred one patients who underwent curative resection of colorectal cancer entered the study and were divided into two groups. In Group 1 the specimen was “en bloc” fixed, and nodes were identified by sight and palpation. In Group 2 the mesentery of the excised specimen was dissected away from the bowel, stretched, and pinned to cork board. The mesenteric segment surrounding the origin of principal vessels was divided from the segment surrounding the colic vessels. All specimen segments were fixed, node identification being performed by sight and palpation. Examined and positive nodes were recorded, and metastatic rate and incidence was calculated in the two groups. Patients were classified with used of different staging systems. Survival rates were calculated, related to tumor stage, and compared statistically. Pathologic procedures were included in a multivariate analysis. RESULTS: A significantly higher number of detected and positive nodes and metastatic rate (37.5vs. 30.2 percent;P<0.05) were observed in Group 2; 45.2 percent of Group 2 and 25.3 percent of Group 1 cases had more than three positive nodes (P<0.05). In Group 2 several patients shifted from earlier to more advanced stages compared with Group 1 cases. Five-year and ten-year survival rates were significantly higher (P=p.pr) in Group 2 (81.5 and 77.2 percent) than in Group 1 (76.7 and 61.5 percent), mostly in patients with TNM Stage N0. Survival analysis related to Astler and Collers and Tangs classifications confinrmed such features. Higher rates of local recurrences and distant metastases were found in Group 1, particularly if related to node status (P<0.05). Multivariate analysis demonstrated the pathologic method is an independent prognostic factor. CONCLUSIONS: This study demonstrates the prognostic impact of specimen examination. Inaccurate methods could downstage the tumor and exclude the patient from adjuvant therapies, with detrimental effects on the outcome of the case.

Locally advanced rectal cancer: MR imaging in prediction of response after preoperative chemotherapy and radiation therapy.

PURPOSE To prospectively differentiate, at magnetic resonance (MR) imaging, patients with locally advanced nonmucinous rectal cancer who will respond to long-course chemotherapy and radiation therapy (CRT) from those who will not respond, with histopathologic results as the reference standard. MATERIALS AND METHODS Institutional review board approval for this study was obtained, and all patients provided written informed consent. High-spatial-resolution T2-weighted MR images were acquired before and 6-8 weeks after CRT in 53 patients (33 men, 20 women; mean age, 63 years; age range, 42-79 years). Patients were categorized as responders to CRT (patients with T3 cancer that converted to T2 or a lower stage, patients with T4 cancer that converted to T3 or a lower stage) or as nonresponders (patients with stable or progressive disease). At the posttreatment MR imaging examination, a decrease in signal intensity was considered to represent a morphologic response with fibrosis. Before CRT and surgery, tumor volume was calculated at MR imaging by multiplying cross-sectional area by section thickness. Tumor length was measured at MR imaging and in the histopathologic specimen. Nodal downstaging was evaluated. The relationship between pathologic response, morphologic MR imaging response, and percentage volume reduction was evaluated with the Mann-Whitney-Wilcoxon two-sample test. RESULTS Morphologic response assessment with MR imaging achieved a positive predictive value (PPV) of 84.2% (32 of 38) and a negative predictive value (NPV) of 66.7% (10 of 15). Volume reduction extent (> or = 70%) was significantly different between patients in whom disease was downstaged and those in whom it was not downstaged (P = .000005) and showed additional diagnostic value, with an overall accuracy of 86.8% (46 of 53). Presurgical MR imaging and histopathologic tumor length did not show a significant difference. MR imaging accuracy for lymph node (N) stage was 86.8% (46 of 53) on the basis of morphologic criteria. CONCLUSION After CRT, morphologic and volumetric evaluation at MR imaging had a high PPV and a low NPV for response assessment. The detection of small clusters of residual tumor cells within fibrosis remains a problem. SUPPLEMENTAL MATERIAL http://radiology.rsnajnls.org/cgi/content/full/250/3/730/DC1.

Prevalence, characteristics and severity of non-alcoholic fatty liver disease in patients with chronic plaque psoriasis

BACKGROUND/AIMS The association between NAFLD and psoriasis has never been explored in prospective epidemiological studies. The aim of this 2-phase study was to study the clinical features of NAFLD in patients with psoriasis. METHODS Phase 1: Investigation of prevalence and characteristics of NAFLD in an unselected cohort of 142 adult Italian outpatients with psoriasis vulgaris. Phase 2: Comparison of the psoriasis cohort subgroup with NAFLD and an age- and body mass index-matched retrospective cohort of 125 non-psoriasis patients with biopsy proven NAFLD. RESULTS Based on histories, laboratory tests, and ultrasound studies, 84 (59.2%) received clinical diagnosis of NAFLD; 30 had factors potentially associated with liver disease other than NAFLD (e.g., viral hepatitis, significant ethanol, methotrexate use); and 28 (19.7%) had normal livers. Comparison of the normal-liver and NAFLD subgroups revealed that NAFLD in psoriasis patients (Ps-NAFLD) was significantly correlated with metabolic syndrome (p<0.05); obesity (p=0.043); hypercholesterolemia (p=0.029); hypertriglyceridemia (p<0.001); AST/ALT ratio >1 (p=0.019), and psoriatic arthritis (PsA) (p=0.036). The association with PsA remained significant after logistic regression analysis (OR=3.94 [CI, 1.07-14.46]). Compared with the retrospective non-psoriatic NAFLD cohort (controls), Ps-NAFLD patients (cases) were likely to have severe NAFLD reflected by non-invasive NAFLD Fibrosis Scores and AST/ALT >1. CONCLUSIONS NAFLD is highly prevalent among psoriasis patients, where it is closely associated with obesity (overall and abdominal), metabolic syndrome, and PsA, and more likely to cause severe liver fibrosis (compared with nonPs-NAFLD). Routine work-up for NAFLD may be warranted in patients with psoriasis, especially when potentially hepatotoxic drug therapy is being considered.

Lactobacillus acidophilus protects tight junctions from aspirin damage in HT-29 cells

Background/Aims: Non-steroidal anti-inflammatory drugs cause enterocyte damage inducing an increase of intestinal permeability. Tight junctions are the key structures in the permeability of the intestinal mucosa. ZO-1 is a tight junction associated protein considered a good marker of their integrity. It has been suggested that probiotics could play a protective role in the intestinal barrier function. We determined, in vitro, whether the heat-killed Lactobacillus acidophilus strain LB (LaLB) with its spent culture supernatant protects tight junctions of HT-29 cells from aspirin (ASA) damage. Methods: HT-29 cells were treated with ASA alone or ASA and LaLB with its spent culture supernatant together. Morphological alterations of tight junctions were evaluated by immunofluorescence using an anti-ZO-1 antibody. Moreover, a semiquantitative assay for ZO-1 was performed by Western blot. Results: Immunofluorescence analysis showed a fragmented and granulous ZO-1 staining, after ASA treatment. Using both ASA and LaLB with its spent culture supernatant together, we found a fine continuous linear web at cell-cell contacts similarly to control. Western blot revealed that ASA inhibited ZO-1 expression and LaLB with its spent culture supernatant counteracted this effect. Conclusions: This pilot study shows, for the first time, the protective effect of LaLB with its spent culture supernatant on tight junctions from ASA damage. These results suggest that probiotics could play a role in the prevention of ASA-induced alterations of intestinal permeability.

Simultaneous immunohistochemical expression of HBME-1 and galectin-3 differentiates papillary carcinomas from hyperfunctioning lesions of the thyroid

Aims : The histological diagnosis is critical for the postsurgical management and follow‐up of thyroid malignancies. The differential diagnosis between papillary carcinoma and hyperfunctioning lesions, either with papillary hyperplasia or with a follicular architecture, can create real diagnostic difficulty. The aim of this study was to evaluate the expression of several antibodies considered to be markers of malignancy in malignant and hyperfunctioning thyroid neoplasms and to include the most effective of them in a diagnostic panel.

Immunohistochemical analysis of pRb2/p130, VEGF, EZH2, p53, p16INK4A, p27KIP1, p21WAF1, Ki-67 expression patterns in gastric cancer†

Although the considerable progress against gastric cancer, it remains a complex lethal disease defined by peculiar histological and molecular features. The purpose of the present study was to investigate pRb2/p130, VEGF, EZH2, p53, p16INK4A, p27KIP1, p21WAF1, Ki‐67 expressions, and analyze their possible correlations with clinicopathological factors. The expression patterns were examined by immunohistochemistry in 47 patients, 27 evaluated of intestinal‐type, and 20 of diffuse‐type, with a mean follow up of 56 months and by Western blot in AGS, N87, KATO‐III, and YCC‐2, ‐3, ‐16 gastric cell lines. Overall, stomach cancer showed EZH2 correlated with high levels of p53, Ki‐67, and cytoplasmic pRb2/p130 (P < 0.05, and P < 0.01, respectively). Increased expression of EZH2 was found in the intestinal‐type and correlated with the risk of distant metastasis (P < 0.05 and P < 0.01, respectively), demonstrating that this protein may have a prognostic value in this type of cancer. Interestingly, a strong inverse correlation was observed between p27KIP1 expression levels and the risk of advanced disease and metastasis (P < 0.05), and a positive correlation between the expression levels of p21WAF1 and low‐grade (G1) gastric tumors (P < 0.05), confirming the traditionally accepted role for these tumor‐suppressor genes in gastric cancer. Finally, a direct correlation was found between the expression levels of nuclear pRb2/p130 and low‐grade (G1) gastric tumors that was statistically significant (P < 0.05). Altogether, these data may help shed some additional light on the pathogenetic mechanisms related to the two main gastric cancer histotypes and their invasive potentials. J. Cell. Physiol. 210: 183–191, 2007.

Direct visualization of intestinal villi by high-resolution magnifying upper endoscopy: a validation study

BACKGROUND New generation videoendoscopes potentially may visualize duodenal villi. This study compared endoscopic findings with this type of instrument to the histopathologic evaluation of duodenal villi. METHODS A total of 191 patients underwent upper endoscopy for the purpose of obtaining duodenal biopsy specimens. The findings were assessed independently by 3 experienced observers by using a commercially available, high-resolution, high-magnifying (x2) videoendoscope. The duodenal villous profile was determined by endoscopic magnification and by endoscopic magnification after filling the duodenum with water. With both endoscopic magnification and endoscopic magnification after filling the duodenum with water, villous patterns were scored as the following: definitely present, partially present, or definitely absent. Villous patterns also were histopathologically scored as the following: normal, partial villous pattern, or total villous atrophy. RESULTS Interobserver variability was excellent (kappa = 0.93). The concordance between either endoscopic magnification or endoscopic magnification after filling the duodenum with water and histology was 100% for presence/absence of villi. The sensitivity, the specificity, and the positive and negative predictive values of endoscopic magnification for detection of any villous abnormality were 95%, 99%, 95%, and 99%, respectively; the respective values of endoscopic magnification after filling the duodenum with water were 95%, 98%, 92%, and 99%. CONCLUSIONS High-resolution magnifying upper endoscopy can reliably predict the presence or the absence of duodenal villi.

Diffusion-Weighted Magnetic Resonance Imaging in Monitoring Rectal Cancer Response to Neoadjuvant Chemoradiotherapy

PURPOSE To prospectively monitor the response in patients with locally advanced nonmucinous rectal cancer after chemoradiotherapy (CRT) using diffusion-weighted magnetic resonance imaging. The histopathologic finding was the reference standard. METHODS AND MATERIALS The institutional review board approved the present study. A total of 62 patients (43 men and 19 women; mean age, 64 years; range, 28-83) provided informed consent. T(2)- and diffusion-weighted magnetic resonance imaging scans (b value, 0 and 1,000 mm(2)/s) were acquired before, during (mean 12 days), and 6-8 weeks after CRT. We compared the median apparent diffusion coefficients (ADCs) between responders and nonresponders and examined the associations with the Mandard tumor regression grade (TRG). The postoperative nodal status (ypN) was evaluated. The Mann-Whitney/Wilcoxon two-sample test was used to evaluate the relationships among the pretherapy ADCs, extramural vascular invasion, early percentage of increases in ADCs, and preoperative ADCs. RESULTS Low pretreatment ADCs (<1.0 × 10(-3)mm(2)/s) were correlated with TRG 4 scores (p = .0011) and associated to extramural vascular invasion with ypN+ (85.7% positive predictive value for ypN+). During treatment, the mean percentage of increase in tumor ADC was significantly greater in the responders than in the nonresponders (p < .0001) and a >23% ADC increase had a 96.3% negative predictive value for TRG 4. In 9 of 16 complete responders, CRT-related tumor downsizing prevented ADC evaluations. The preoperative ADCs were significantly different (p = .0012) between the patients with and without downstaging (preoperative ADC ≥1.4 × 10(-3)mm(2)/s showed a positive and negative predictive value of 78.9% and 61.8%, respectively, for response assessment). The TRG 1 and TRG 2-4 groups were not significantly different. CONCLUSION Diffusion-weighted magnetic resonance imaging seems to be a promising tool for monitoring the response to CRT.

Restaging locally advanced rectal cancer with MR imaging after chemoradiation therapy.

In recent years, preoperative therapy has become standard procedure for locally advanced rectal cancer. Tumor shrinkage due to preoperative chemotherapy-radiation therapy (CRT) is now a reality, and pathologically complete responses are not uncommon. Some researchers are now addressing organ preservation, thus increasing the demand for both functional and morphologic radiologic evaluation of response to CRT to distinguish responding from nonresponding tumors. On magnetic resonance (MR) images, post-CRT tumor morphologic features and volume changes have a high positive predictive value but a low negative predictive value for assessing response. Preliminary results indicate that diffusion-weighted MR imaging, especially at high b values, would be effective for prediction of treatment outcome and for early detection of tumor response. Some authors have reported that the use of apparent diffusion coefficient values in combination with other MR imaging criteria significantly improves discrimination between malignant and benign lymph nodes. Sequential determination of fluorodeoxyglucose uptake at positron emission tomography/computed tomography has proved useful in differentiating responding from nonresponding tumors during and at the end of CRT. However, radionuclide techniques have limitations, such as low spatial resolution and high cost. Large studies will be needed to verify the most effective morphologic and functional imaging modalities for post-CRT restaging of rectal cancer. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.303095085/-/DC1.