Colonic overexpression of the T-type calcium channel Cav 3.2 in a mouse model of visceral hypersensitivity and in irritable bowel syndrome patients.

BACKGROUND: Among the different mechanisms involved in irritable bowel syndrome (IBS) physiopathology, visceral hypersensitivity seems to play a key role. It involves sensitization of the colonic primary afferent fibers, especially through an overexpression of ion channels. The aims of this translational study were to investigate the colonic expression of Cav 3.2 calcium channels and their involvement in an animal model of colonic hypersensitivity, and to assess their expression in the colonic mucosa of symptomatic IBS patients. METHODS: This bench-to-bed study combined a preclinical experimental study on mice and a case-control clinical study. Preclinical studies were performed on wild-type and Cav 3.2-KO mice. Colonic sensitivity and Cav 3.2 expression were studied after a low-dose treatment of dextran sodium sulfate (DSS 0.5%). Regarding the clinical study, colonic biopsies were performed in 14 IBS patients and 16 controls during a colonoscopy to analyze the mucosal Cav 3.2 expression. KEY RESULTS: Wild-type, but not Cav 3.2-KO, mice developed visceral hypersensitivity without colonic inflammation, after 0.5% DSS treatment. A significant increase of Cav 3.2 mRNA (p = 0.04) was found in the colon of low-dose DSS-treated wild-type (WT) mice compared to their controls. In human colonic biopsies, the Cav 3.2 mRNA level was significantly higher in the IBS group compared to the control group (p = 0.01). The immunofluorescence staining revealed their protein expression in colonic mucosa, particularly in nerve fibers. CONCLUSIONS & INFERENCES: This translational study supports the involvement of the calcium channels Cav 3.2 in abdominal pain, as observed in IBS patients. It opens new therapeutic perspectives based on molecules specifically blocking these channels.

Fat-containing lesions of the liver: a pictorial essay.

The presence of fat within a hepatic lesion is unusual and can help to direct the radiologist's diagnosis. The aim of this iconographic review is to specify the various hepatic lesions that may contain fat and their appearance particularly on MRI. A histological correlation is also suggested for the most commonly found tumors. The identification of fat within a hepatic tumor, along with other radiological signs and reflection on the clinical and epidemiological context, can lead to a diagnosis being reached or suggested, with confirmation if necessary, by a pathological examination.

A feature selection based framework for histology image classification using global and local heterogeneity quantification.

Biopsy remains the gold standard for the diagnosis of chronic liver diseases. However, the concordance between readers is subject to variability causing an increasing need of objective tissue description methods. A complete framework has been implemented to analyze histological images from any kind of tissue. Based on the feature selection approach, it computes the most relevant subset of descriptors in terms of classification from a wide initial list of local and global descriptors. In comparison with equivalent methods, this implementation is able to find lists of descriptors which are significantly shorter for an equivalent accuracy and furthermore it enables the classification of slides using combinations of global and local measurements. The results have pointed that it could reach an accuracy of 82.8% in a human liver fibrosis grading approach by selecting 6 descriptors from an initial set of 258 global and local descriptors.

Hepatic haemangioma: common and uncommon imaging features.

The haemangioma, the most common non-cystic hepatic lesion, most often discovered by chance, may in certain situations raise diagnostic problems in imaging. In this article, the authors first demonstrate that the radiological appearance of the hepatic haemangioma, in its typical form, is closely related to three known histological sub-types. They then show that certain atypical features should be known in order to establish a diagnosis. They also observe the potential interactions between the haemangioma, an active vascular lesion, and the adjacent hepatic parenchyma. Finally, they discuss the specific paediatric features of hepatic haemangiomas and illustrate the case of a hepatic angiosarcoma.

[Liver capsule retraction adjacent to a circumscribed liver lesion: review of 26 cases with histological confirmation]. / Rétraction capsulaire hépatique en regard d'une lésion circonscrite: à propos de 26 patients avec preuve histologique.

PURPOSE: To review the histological features of 26 circumscribed liver lesions associated with liver capsule retraction and discuss the differential diagnosis while evaluating for the presence of fibrous stromal reaction. Materials and methods. Retrospective study performed between January 2005 and June 2008 including 26 patients: 18 males and 6 females, without history of cancer, aged between 42 and 82 years (mean age: 64.5 years), presenting with liver capsule retraction adjacent to a circumscribed liver lesion detected on CT or MRI. A single lesion was present in 17 patients, and multiple lesions were present in 9 patients. All liver lesions were biopsied with semi-quantitative evaluation of fibrous stromal reaction. RESULTS: Twenty-one patients had benign or malignant liver tumors and 5 patients had confluent hepatic fibrosis. Twenty of 21 liver tumors were malignant (95.2%): 3 intra-hepatic cholangiocarcinoma, 17 cases of metastatic disease including colorectal carcinoma (n=8), bronchogenic carcinoma (n=1), pancreatic carcinoma (n=4), esophageal carcinoma (n=1), breast carcinoma (n=1), gallbladder carcinoma (1) and endocrine neoplasm of the pancreas (n=1), and 1 case of liver sclerosing angioma (n=1). There was no case of hepatoma. Excluding the 5 cases of confluent hepatic fibrosis, fibrous stromal reaction was present in 15 of 21 cases. CONCLUSION: The presence of capsular retraction next to a circumscribed liver lesion, while non-specific, is suspicious. In keeping with previous reports, metastases were frequently the cause and intrahepatic cholangiocarcinoma was the most frequent primary tumor. In patients with chronic hepatocellular disease, confluent fibrosis was a frequent etiology. The fibrous component of the underlying malignant lesion along with its subcapsular location appear to be determining factors in the development of capsular retraction.

[Regression in primary cutaneous melanoma is not predictive for sentinel lymph node micrometastasis]. / Absence de valeur prédictive des signes de régression histologique sur l'envahissement du ganglion sentinelle.

BACKGROUND: The predictive value of regression in melanoma is debated. AIM OF THE STUDY: A retrospective single-centre study to evaluate the correlation between regression in primary skin tumor and the presence of micrometastases in sentinel lymph nodes. PATIENTS AND METHODS: Histological signs of regression in 84 melanomas (>1 mm) with corresponding sentinel lymph nodes were studied by two independent pathologists. RESULTS: Regression was seen in 40 skin melanoma tumors while micrometastasis was seen in 24. Of the tumors with micrometastasis, only 10 were regressive (RR: 0.47, p=0.49). Breslow value>2 mm and male sex were predictive for node micrometastasis (RR: 4.6, p=0.03 and RR: 7.6, p=0.006, respectively). On multivariate analysis, these two factors were independent. COMMENTS: These data suggest that regression in primary cutaneous melanoma is not predictive for lymph node metastasis.

[Do bipolar scissors increase postoperative adhesions? An experimental double-blind randomized trial]. / Les ciseaux bipolaires augmentent-ils les adhérences postopératoires? Etude expérimentale randomisée en double aveugle.

AIM: The use of bipolar scissors (PowerStar) which has been suggested to reduce bleeding during surgical dissection, involves the theoretical risk for increasing intraperitoneal adhesions because of burn damages to the peritoneum secondary to bipolar electrocautery. MATERIAL AND METHOD: Thirty-six white new-Zealand rabbits have been included in a double-blind randomised trial to undergo a laparotomy using either a sharp scissors with on-demand monopolar coagulation or a bipolar scissors. Operatives procedures were standardised: midline laparotomy (5 cm), mobilisation of the right colon, incision of the colonic serosa without suture, incision of the colonic serosa with running sutures, incision of the mesentery. All these steps were performed by the same device according to the randomisation. Ten days later, the rabbits were killed. Adhesions were measured and scored according to the Zühlke classification by a surgeon who was not aware of the type of scissors used. Finally a pathological examination of adhesion was randomly performed. RESULTS: The two groups were similar for weight and sex-ratio. Two rabbits died before the tenth postoperative day (1 unknown aetiology and 1 evisceration). 34 rabbits were available for the study (18 in the "PowerStar" group and 16 in the control group). The results showed no significant difference between the groups for all measured endpoints (length and score of intraperitoneal and parietal adhesions). Nevertheless, pathological examination showed the burn damages to be less pronounced after using PowerStar. CONCLUSION: Bipolar scissors do not increase postoperative adhesions in the rabbit and probably induce less burn damages than monopolar cautery. The additional advantage i.e. the decrease adhesions formation, because of a less intraperitoneal bleeding, has not been observed in this randomised trial.