Examination of germination receptors of B. subtilis and B. megaterium

Many bacterial species including those in the Bacilli group form spores as a mechanism to survive harsh conditions such as extreme temperature, radiation, chemicals, and nutrient starvation. By forming spores, they can remain metabolically dormant for an extended period and revert to their vegetative form when environment becomes favorable. This resumption of metabolism and growth is marked by a process called germination that is triggered by exogenous nutrients such as amino acids, sugars, and nucleotides. The (Ger) germination receptors that are postulated to respond to these germinants, in the case of B. subtilis and B. megaterium, are a complex of at least three different proteins (the A-, B-, and C- subunits) transcribed from the same operon. While similar in gene arrangement and protein complex formation, these two Bacilli sp. respond to different germinants. This experiment investigates the GerA receptor of B. subtilis and the GerU receptor from B. megaterium. GerA of B. subtilis is activated with L-alanine, while GerU of B. megaterium is activated with L-proline. In order to determine the location of the binding site, different fragments of the GerAB gene and the GerUB genes encoding for protein A and B from each operon were amplified and fused together in frame to make a chimeric gene product. recombination. Spores from B. subtilis mutant strains expressing chimeric protein complexes will be tested for germination in the presence of L-proline and/or L-alanine. These studies will provide insights into how bacteria sense their environment and possible strategies to control and prevent growth

Natural history, clinicopathologic classification and prognosis of gastric ECL cell tumors.

A series of 50 gastric endocrine tumors classified according to Rindi et al. [1] comprised 12 small cell neuroendocrine carcinomas (NEC) and 38 ECL cell carcinoids, of which 22 associated with type A chronic atrophic gastritis (A-CAG), eight with hypertrophic gastropathy due to combined Multiple Endocrine Neoplasia and Zollinger/Ellison syndrome (MEN/ZES), and eight sporadic. Variables found to predict tumor malignancy were: size > 2 cm, > 2 mitoses and > 130 Ki67 positive cells/10 high power fields (HPF), grade 2 or 3 histology, angioinvasion, p53 protein nuclear accumulation, and the presence of a single tumor. None of these factors increased significantly the predicting ability of tumor classification itself, although grade 2 + 3 shows 100 percent negative predictive value and Ki67 and angioinvasion 100 percent positive predictive value. When the mostly non-malignant A-CAG and MEN-ZES tumors were analysed against the mostly malignant sporadic and NEC tumors, a positive predictive value of 90 percent and a negative predictive value of 93 percent was obtained. Investigation of a larger tumor series is under way with the aim to develop an optimal model for prognostic evaluation of gastric endocrine tumors

Omitting duodenal biopsy in children with suspected celiac disease and extra-intestinal symptoms

The aim of our study is to evaluate if in children with highly positive serology and HLA-DQ2/DQ8 (triple test, TT) and only extra-intestinal symptoms, it is possible to omit performing an intestinal biopsy for celiac disease (CD) diagnosis, as suggested by the new European Society for Pediatric Gastroenterology, Hepatology and Nutrition ESPGHAN guidelines

The significance of duodenal mucosal atrophy in patients with common variable immunodeficiency: a clinical and histopathological study

Gastrointestinal manifestations and villous atrophy can be seen in patients with common variable immunodeficiency (CVID). In some patients, infectious agents may be responsible, whereas in Others, celiac diseases (CD) may be the cause. In this study, we investigate the causes and th ehistopathologic festures seen in patients with CVID. Eleven patients with CVID and villous atrophy underwent duodenal biopsies, human leukocyte antien (HLA) typing, and testing for all celiac antibodies. Fifteen patients with CVID and normal villi and 6 patients with CD but without CVID served as controls. Histologic response to a gluten-free diet (GFD) allowed a diagnosis of CD in 3 of 11 patients. In the remaining 8, the lack of a histologic response to a GFD or HLA typing excluded CD. Celiac antibodies gave conflicting results and were of no help. Polymorphonuclear infiltrates and lesions like graft-versus-host disease are seen more ofter in flat mucos aunresponsive to a GFD. However, the specificity of these findings remains to be determined and response to a GFD remains the only diagnostic criteria for CD in these patients. Villous atrophy was gluten-sensitive in 3 of 11 patients with CVID. It was not related to gluten-responsive CD in most patients

Prevalence and natural history of potential coeliac disease in adult patients.

OBJECTIVE: Potential celiac disease (PCD) is a form of CD characterized by positive endomysial/tissue transglutaminase antibodies and a preserved duodenal mucosa despite a gluten-containing diet (GCD); it can evolve into flat, active CD. This evolution is, however, not certain. Our aim was to retrospectively study the prevalence and the natural history of adult patients with PCD. METHODS: The clinical notes of all 47 patients with PCD attending our clinic between September 1999 and October 2011 were retrospectively reevaluated. To study their clinical features, patients with active CD, randomly selected and matched for sex and date of birth, served as controls. Symptoms, associated diseases, familiarity, and laboratory data at diagnosis were compared. RESULTS: Prevalence of PCD among all celiac patients directly diagnosed in our center was 42/187, (1/4.4, 18.3%, 95% confidence interval (CI) 13.3-23.4%). Age at diagnosis, laboratory data, prevalence of symptoms, associated diseases, and familiarity for CD did not differ between patients with PCD and those with active CD. Some patients with PCD maintained a normal duodenal mucosa for many years and their symptoms spontaneously improved despite maintaining a GCD. CONCLUSIONS: PCD is not a rare form of CD. Having found no difference at all in age at diagnosis and clinical features between PCD and active CD could suggest that PCD is not a prodrome of CD but is a separate entity that can only subsequently evolve into active CD

Increase in chromogranin A- and serotonin-positive cells in pouch mucosa of patients with ulcerative colitis undergoing proctocolectomy

Background: Inflammatory bowel disease (IBD) is associated with neuroendocrine cell hyperplasia. Aims: We investigated neuroendocrine cells in J-pouches of patients with ulcerative colitis undergoing restorative proctocolectomy and ileal pouch-anal anastomosis. Methods: Sections from pouch biopsies of 17 patients and ileal biopsies of 17 active IBD patients and 16 controls were processed by immunohistochemistry for chromogranin A (CgA) and serotonin. Mucosal tryptophan hydroxylase (TpH)-1 and serotonin-selective reuptake transporter (SERT) transcripts were measured by quantitative RT-PCR. TpH-1 and SERT transcripts were detected in pouch biopsies cultured with infliximab or its isotype control, while interleukin (IL)-6 and IL-8 were measured in biopsy supernatants. Results: A significant increase in CgA-positive cells and serotonin-positive cells was observed in both pouch and IBD ileum compared to control ileum. Significantly raised transcripts of TpH-1, but not SERT, were found in IBD ileum in comparison to control ileum, with no significant difference between pouch and IBD ileum. Infliximab had no influence on ex vivo pouch expression of TpH-1 and SERT, nor on the production of IL-6 and IL-8. Conclusion: We here demonstrated neuroendocrine cell hyperplasia in pouch mucosa. Further studies are needed to clarify the pathophysiological implication of this finding

Prognostic relevance and putative histogenetic role of cytokeratin 7 and MUC5AC expression in Crohn\u2019s disease-associated small bowel carcinoma

Most Crohn\u2019s disease-associated small bowel carcinomas (CrD-SBCs) are diagnosed in advanced stage and have poor prognosis. To improve diagnosis and therapy, a better knowledge of tumour precancerous lesions, histotypes and prognostic factors is needed. We investigated histologically and immunohistochemically 52 CrD-SBCs and 51 small bowel carcinomas unrelated to inflammatory disease, together with their tumour-associated mucosa, looking for Crohn-selective changes. Histologic patterns and phenotypic markers potentially predictive of CrD-SBC histogenesis and prognosis were analysed. Cytokeratin 7 or MUC5AC-positive metaplastic changes were found in about half of investigated CrD-SBCs, significantly more frequently than in CrD-unrelated SBCs. They correlated with metaplastic changes of their associated mucosa, while being absent in normal ileal mucosa. Histologic patterns suggestive for progression of some cytokeratin 7 and/or MUC5AC-positive metaplastic lesions into cancer of the same phenotype were also observed. Patient survival analyses showed that tumour cytokeratin 7 or MUC5AC expression and non-cohesive histotype were adverse prognostic factors at univariable analysis, while cytokeratin 7 and non-cohesive histotype were also found to predict worse survival in stage- and age-inclusive multivariable analyses. Besides conventional dysplasia, hyperplasia-like non-conventional lesions were observed in CrD-SBC-associated mucosa, with patterns suggestive for a histogenetic link with adjacent cancer. In conclusion the cytokeratin 7 and/or MUC5AC-positive metaplastic foci and the non-conventional growths may have a role in cancer histogenesis, while tumour cytokeratin 7 and non-cohesive histotype may also predict poor patient survival. Present findings are worth being considered in future prospective histogenetic and clinical studies

Endoscopic Submucosal Dissection of Early Gastric Cancer

Gastric cancer is the most common cancer worldwide. The proportion of early gastric cancer (EGC) cases at diagnosis has increased because of the use of mass screening endoscopy in older adults. Endoscopic mucosal resection has become the standard treatment for EGC in cases with standard indications because of its low risk of lymph node metastasis. A new endoscopic method, endoscopic submucosal dissection, has recently become available. This method allows en bloc resection without limitation of the size of the lesion. The goal of this article is to review the history and methods of endoscopic treatment with EGC, the conventional and extended indications, the therapeutic outcomes, and the complication rates

New insights into the role of age and carcinoembryonic antigen in the prognosis of colorectal cancer

The aim of this study was to verify through relative survival (an estimate of cancer-specific survival) the true prognostic factors of colorectal cancer. The study involved 506 patients who underwent locally radical resection. All the clinical, histological and laboratory parameters were prognostically analysed for both overall and relative survival. This latter was calculated from the expected survival of the general population with identical age, sex and calendar years of observation. Univariate and multivariate analyses were applied to the proportional hazards model. Liver metastases, age, lymph node involvement and depth of bowel wall involvement were independent prognosticators of both overall and relative survival, whereas carcinoembryonic antigen (CEA) was predictive only of relative survival. Increasing age was unfavourably related to overall survival, but mildly protective with regard to relative survival. Three out of the five prognostic factors identified are the cornerstones of the current staging systems, and were confirmed as adequate by the analysis of relative survival. The results regarding age explain the conflicting findings so far obtained from studies considering overall survival only and advise against the adoption of absolute age limits in therapeutic protocols. Moreover, the prechemotherapy CEA level showed a high clinical value