Hydrogen sulfide dysfunction in metabolic syndrome-associated vascular complications involves cGMP regulation through soluble guanylyl cyclase persulfidation.

Here, by using in vitro and ex vivo approaches, we elucidate the impairment of the hydrogen sulfide (H2S) pathway in vascular complications associated with metabolic syndrome (MetS). In the in vitro model simulating hyperlipidemic/hyperglycemic conditions, we observe significant hallmarks of endothelial dysfunction, including eNOS/NO signaling impairment, ROS overproduction, and a reduction in CSE-derived H2S. Transitioning to an ex vivo model using db/db mice, a genetic MetS model, we identify a downregulation of CBS and CSE expression in aorta, coupled with a diminished L-cysteine-induced vasorelaxation. Molecular mechanisms of eNOS/NO signaling impairment, dissected using pharmacological and molecular approaches, indicate an altered eNOS/Cav-1 ratio, along with reduced Ach- and Iso-induced vasorelaxation and increased L-NIO-induced contraction. In vivo treatment with the H2S donor Erucin ameliorates vascular dysfunction observed in db/db mice without impacting eNOS, further highlighting a specific action on smooth muscle component rather than the endothelium. Analyzing the NO signaling pathway in db/db mice aortas, reduced cGMP levels were detected, implicating a defective sGC/cGMP signaling. In vivo Erucin administration restores cGMP content. This beneficial effect involves an increased sGC activity, due to enzyme persulfidation observed in sGC overexpressed cells, coupled with PDE5 inhibition. In conclusion, our study demonstrates a pivotal role of reduced cGMP levels in impaired vasorelaxation in a murine model of MetS involving an impairment of both H2S and NO signaling. Exogenous H2S supplementation through Erucin represents a promising alternative in MetS therapy, targeting smooth muscle cells and supporting the importance of lifestyle and nutrition in managing MetS.

CA 72-4 measurement of tumor-associated glycoprotein 72 (TAG-72) as a serum marker in the management of gastric carcinoma.

The presence of three distinct serum markers of carcinoma, tumor-associated glycoprotein 72 (TAG-72; as measured by the CA 72-4 assay), CA 19-9, and carcinoembryonic antigen (CEA), was evaluated in 194 patients diagnosed with either malignant (n = 94) or benign (n = 100) gastric disease. Of the 94 patients diagnosed with gastric carcinoma, the percentage of patients whose serum samples were positive for TAG-72, CA 19-9, or CEA was 42.6, 31.9, and 20.2%, respectively. Furthermore, fewer false positive samples were observed for TAG-72 than either CA 19-9 or CEA. The analysis of serum TAG-72, CA 19-9, and CEA levels in patients diagnosed with early (stage I and II) versus advanced (stage III and IV) disease revealed a significantly higher level of TAG-72 and CA 19-9 in the serum of patients with advanced stage gastric carcinoma. The serum samples were also analyzed to determine whether any advantage might be gained by simultaneously measuring two or more of the tumor markers. The data clearly indicate that the measurement of TAG-72 with CA 19-9 significantly increased the percentage of gastric carcinoma patients with positive serum levels of either antigen. This advantage was achieved with no significant increase in the number of false positives. Twenty-one patients were followed postsurgically for up to 3 years to determine whether the appearance or reappearance of TAG-72, CA 19-9, or CEA accurately predicted disease recurrence. Positive serum TAG-72 levels correlated with disease recurrence in 7 of 10 patients, compared with 5 and 2 patients for CA 19-9 and CEA, respectively. The findings suggest that serum TAG-72 as measured by the CA 72-4 assay may be a useful marker for late stage gastric carcinoma and its measurement alone or in combination with CA 19-9 may have utility in the clinical management of gastric carcinoma.

Unbalanced germ-line expression of hMLH1 and hMSH2 alleles in hereditary nonpolyposis colorectal cancer.

We analyzed the hMLH1 and hMSH2 genes in 30 unrelated hereditary nonpolyposis colorectal cancer (HNPCC) patients using mutational and immunohistochemical analyses combined whenever possible with primer extension assays, designed to estimate hMLH1 and hMSH2 transcript expression in peripheral blood lymphocytes. Single-strand conformational polymorphism screening and PCR-direct sequencing revealed seven hMLH1 and five hMSH2 sequence variants in 14 unrelated HNPCC patients, including three definite pathogenic mutations, four amino acid substitutions of uncertain pathogenic significance, and five polymorphisms. Immunohistochemistry indicated the lack of either hMLH1 or hMSH2 protein expression in tumors from 13 patients, and the absence of both hMLH1 and hMSH2 immunostaining was observed in the tumor from one additional case. The lack of hMLH1 or hMSH2 immunostaining was associated with the presence of microsatellite instability in the corresponding tumor and was also observed in tumors from patients negative for pathogenic mutations by mutational screening. There was a marked unbalance in the allelic expression of either hMLH1 or hMSH2 transcripts in three of eight unrelated HNPCC patients that could be analyzed, although a less marked unbalance was detected in two additional patients. Tumors from patients with germ-line unbalance in hMLH1 or hMSH2 transcript expression did not express the corresponding mismatch repair protein and displayed microsatellite instability. Our results indicate that constitutional alterations in hMLH1 and hMSH2 transcript expression may represent genetic markers for HNPCC carrier status also in cases in which mutational analysis did not detect a definite pathogenic variant. This suggests that transcript deregulation may represent a relevant mode of germ-line inactivation for mismatch repair genes.

Correlation between tumor-associated glycoprotein 72 mucin levels in tumor and serum of colorectal patients as measured by the quantitative CA 72-4 immunoassay.

Colorectal tissue biopsies were obtained from 110 patients diagnosed with primary colorectal carcinoma (tumor and normal colonic mucosa samples), 20 patients diagnosed with benign colorectal disease, and 31 healthy donors. The level of expression of tumor-associated glycoprotein 72 (TAG-72) was quantitatively measured in each sample using a double-determinant RIA with monoclonal antibodies B72.3 and CC49 and detecting the sialyl-Tn epitope; this assay was termed CA 72-4. Statistical analysis revealed a significant (approximately 10-fold) increase of TAG-72 expression in the colon tumor biopsies when compared with the expression in normal colonic mucosa from the same patients. A regression analysis revealed a significant correlation (r = 0.459; P < 0.001) between TAG-72 levels measured in biopsies from the tumor lesions and those found in the corresponding normal colonic mucosa. Furthermore, regression analysis showed a significant positive correlation between TAG-72 levels in the tumors and sera of the same patients (r = 0.491; P < 0.001). TAG-72 levels in normal colonic mucosa from healthy donors and patients diagnosed with colorectal cancer were compared. TAG-72 expression was 5-fold higher in the normal mucosa from the colorectal carcinoma patients. No relationship between TAG-72 tumor tissue content and stage of disease was found. Moreover, the correlation between TAG-72 distribution and degree of tumor differentiation observed (P < 0.05) was not any more evident when mucinous carcinomas were excluded. Finally, the results provide further evidence that TAG-72 may be considered an important early marker for colorectal cancer and/or other dysplastic colonic diseases. The statistical correlation between TAG-72 levels in tumors and circulating TAG-72 indicates that patients with elevated levels of serum TAG-72, as measured by the CA 72-4 assay, would be most suited for diagnostic and/or therapeutic intervention with the anti-TAG-72 monoclonal antibodies B72.3 or CC49 or vaccine trials using the sialyl-Tn epitope.

Novel allele of the hMLH1 gene bearing a TTC deletion in the 3' untranslated region.

SSCP analysis of the hMLH1 gene in two kindreds affected by hereditary nonpolyposis colorectal cancer (HNPCC) revealed the presence of unique conformers in all patients affected by colorectal cancer. Sequence analysis of the corresponding region of the gene revealed a 3 base pairs deletion within a TTC tandem repeat (G TTC TCC T-->G TTC T) beginning 29 base pairs downstream of the termination codon of the gene in the 3' untranslated region. This deletion causes the loss of an MboII restriction site. Analysis extended to 113 healthy unrelated individuals and 27 unrelated HNPCC patients demonstrated the occurrence of this novel variant of the hMLH1 gene at similar frequencies in unrelated HNPCC patients (3.7%) and in control individuals (2.2%). The allele bearing the TTC deletion appears to be expressed at levels comparable to those of the wild-type allele.

Detection of Helicobacter pylori carriers by discriminant analysis of urea and pH levels in gastric juices.

An alternative approach to the problems inherent in current methods for detecting Helicobacter pylori carriers--that of being generally time-consuming, expensive, and not sufficiently sensitive--was devised by using the urea concentration and pH levels of gastric juices. A linear discriminant analysis of these variables, measured in 54 patients submitted to digestive endoscopy for gastritis, provided a mathematical formula for assigning the subjects (previously classified by other standard methods) to groups of either positive or negative H pylori carriers. The results obtained showed a correct classification in 52 out of 54 cases with only one false negative and one false positive case.

Detection of C-myb genetic alterations and mutant p53 serum protein in patients with benign and malignant colon lesions.

C-myb structural alterations were analysed by Southern blot hybridization in 55 adenomatous polyps and 21 adenocarcinomas of the colon. Gene amplification was observed in 8 cases (14.5%) and c-myb rearrangements in 3 cases (5.4%) of the preneoplastic lesions analysed. A higher percentage of c-myb abnormalities (23.8%) was shown by malignant tumors. As far as mutant p53 protein is concerned, it was detected both in sera of adenoma and adenocarcinoma patients, though at different levels. No statistically significant correlations were found between c-myb or p53 abnormalities and clinico-pathological variables.

Activation of c-MYC and c-MYB proto-oncogenes is associated with decreased apoptosis in tumor colon progression.

BACKGROUND: An increasing amount of evidence suggests that progression from normal mucosa to colorectal cancer is accompanied by morphological and genetic alterations. Genetic abnormalities affect malignant transformation via a gradual imbalance of normal tissue homeostasis involving programmed cell death (PCD) or apoptosis. Therefore, it has been hypothesized that alterations in apoptosis may contribute to carcinogenesis. The aim of the present work was to investigate the relationship between frequency of spontaneous apoptosis during transition adenoma-to-carcinoma of the colorectal tract and the incidence of activation of c-myc and c-myb proto-oncogenes, involved both in colon tumorigenesis and apoptosis. MATERIALS AND METHODS: Ninety-five tissue specimens (60 polyps and 35 adenocarcinomas) were removed with autologous normal adjacent mucosa from colon cancer patients. Genomic DNA was extracted and analyzed for both apoptosis frequency (DNA fragmentation assay) and proto-oncogene activation (Southern blot analysis). On the same samples, Bcl-2 protein expression was evaluated by immunohistochemistry. RESULTS: Our results showed that: i) a significant relationship exists between apoptosis and genesis of colorectal cancer since, compared to adenomatous polyps and adjacent normal mucosa, cell death is markedly inhibited in tumors (p = 0.01); ii) during colon tumor progression, apoptosis and amplifications of c-myc/c-myb genes are inversely related; iii) Bcl-2 expression is retained in colon tumors even though at a significantly lower level with respect to adenomatous polyps. CONCLUSION: These results indicate that failure of the normal apoptotic process together with de-regulation of c-myc and c-myb proto-oncogenes might promote the development of colorectal tumors.

Evaluation of the CA 242 tumor antigen as a potential serum marker for colorectal cancer.

OBJECTIVE: The present study was designed to define the performance of serum CA 242 as a marker in colorectal cancer patients. PATIENTS AND METHODS: Serum samples from 1,013 subjects (440 healthy volunteers, 384 patients with primary or recurrent colorectal carcinoma and 189 with benign colorectal diseases) were evaluated. RESULTS: The measurement of serum CA 242 levels in the population of healthy subjects demonstrated the presence of positive levels in approximately 5% of the cases. Interestingly, similar results (5.8%) were obtained in patients with benign colorectal disease, demonstrating the high specificity of CA 242. When serum samples from colorectal cancer patients were analyzed, a sensitivity of 34.9% was observed. Moreover, 18.6% Stage A and B patients had positive CA 242 levels, compared to 33.3% and 58.8% of Stage C and D patients, respectively, indicating a correlation with the stage of disease. A comparison between preoperative and immediate postoperative CA 242 levels showed a consistent relationship between the efficacy of surgery and the reduction in serum CA 242 levels; further, elevated CA 242 levels were present in the immediate postsurgical follow-up of patients undergoing palliative surgery. A longitudinal evaluation of serum CA 242 levels demonstrated that this marker was indicative of the status of disease. CONCLUSIONS: The results obtained suggest the possible utility of CA 242 in monitoring the disease status, providing a rationale for future studies focusing on the longitudinal monitoring of colorectal cancer patients.

Colorectal cancer complicating ulcerative colitis: an institutional series.

Ulcerative colitis predisposes to colorectal cancer: the risk increases along with disease duration and extension. Also some subsets of patients are at increased risk, namely patients with early onset of colitis, and patients with primary sclerosing cholangitis. Cancer complicating ulcerative colitis affects evenly all the colon, and is not located more frequently in the rectum and in the sigmoid colon, as well as the sporadic counterpart. Multiple cancers and cancers associated with high grade dysplasia are not infrequent in ulcerative colitis; for this reason, and for controlling the colitis, the treatment of choice is total colectomy, with or without colostomy. The prognosis of cancer complicating ulcerative colitis is similar to the sporadic counterpart. The Authors present a colon cancers series as a complication of colitis occurred at Regina Elena Cancer Institute of Rome, Italy, over the period 1975-1998.

Endoscopic palliative therapy in neoplastic diseases of the esophagus.

Over the past 20 years, fiberoptic endoscopy, followed by video-endoscopy, has taken on an increasingly important role in the diagnostics and therapy for digestive tract diseases. Especially in the field of oncology, endoscopy is fundamental not only for the diagnosis and staging of diseases of the gastroenteric tract but also as definitive and/or palliative therapy for tumors that do not respond to radical treatment. Endoscopic techniques are widely employed in diseases of the esophagus and the head and neck district. In fact, it is generally accepted that only 35% of patients with cancer of the esophagus or of the cardias may benefit from surgery with 5-year survival rates of about 5% in Western countries (1, 2).

Medium-large polyps of the colon: a contribution for their clinical profile and a proper surveillance.

A retrospective analysis of polypoid lesions of the colon larger than 1 cm was performed with the aim to study their characteristics and a proper surveillance schedule. We reviewed all colon polypoid lesions larger than 1 cm found and treated during the period January 1984- December 1993 that were not considered cancer macroscopically. The records of 361 patients with 391 polyps are the object of this report. The polyps were divided into subgroups according to size: A) less than 20 mm, B) between 21 and 30 mm, and C) larger than 30 mm. Out of 391 polypoid lesions 373 were adenomas: 60% were found in males. The age group distribution showed no differences among the subgroups. The pedunculated type showed a decrease from 69.1% to 43.3% with the increasing of size: inverse figures were observed for sessile polyps. The lesions were mainly located in left colon. Synchronous adenomas were found in 25.4% patients, and metachronous and previous adenomas respectively in 24.8% and 5.2%: no significant difference was present in the subgroups. Synchronous malignancy in the colon was found in 2% of the patients. Histological characteristics demonstrated a decrease of tubular adenoma from 46.5% to 22.6% from subgroup A to C, while villous adenomas increased inversely from 6.6% to 15.1%. The presence of severe dysplasia ranged from 20.9% to 56.1% in subgroups A and C, respectively, and adenomas with invasive cancer showed a significant increase from the subgroup A to C, respectively from 4.3% to 10.5%. During an average 36-month follow-up we observed 2 metachronous colon cancers, surgically treated in Dukes stage B, 84 metachronous adenomas, all less than 10 mm and without malignant alterations. Our data confirm other literature reports regarding the profile of colon adenomas with an increasing risk of malignancy with the increase of size and the presence of villous structure. In our opinion the assessment of a "clean colon" status is important when an adenoma is found in the colon. The proper follow-up for adenomas must be tailored for any individual patient when risk factors such as size, villous structure, personal and family history of neoplastic lesions of the colon are present. The follow-up schedule, presently recommended for colon adenomas, must be flexible according to these parameters.

Turcot syndrome: case report and nosological aspects.

The Turcot syndrome has been defined as the simultaneous presence of multiple polyposis of the colon and a malignant brain tumor. This association is supposed to be genetically transmitted, even though we still do not exactly know whether this occurs in a dominant or recessive way. The case of a 47-year-old man submitted to a right hemicolectomy for cancer and polyposis, following a series of endoscopic polypectomies and, finally, removal of left temporal glioma is here presented.

Palliative treatment of esophageal tumors.

In malignant dysphagia expandable metal stents are commonly used as palliative treatment, but early and late complications and the improvement of dysphagia have not been well described. This report summarizes our experience with expandable metal stents for malignant dysphagia. From 1995 to 2000, we placed 38 metal stents in 36 patients with malignant dysphagia from unresectable esophageal cancer (94.4%). Dysphagia scores, complications and modality of reintervention were evaluated. Dysphagia scores decreased from 3.2 before the stent placement to 2. Immediate complications occured in one patient because of severe pain, it was not possible to perform endoscopic treatments. Other complications included tracheoesophageal fistula (2 patients), tumor overgrowth (5 patients), new stent placements (2 patients), dislocation (2 patients). In conclusions expandable metal stents are safe and effective in the treatment of malignant dysphagia.

Endoscopic follow-up in resected colorectal cancer patients.

Patients resected for colorectal cancer are at risk for anastomotic recurrence, for adenomatous polyps and for metachronous cancer. The present retrospective study was conducted to evaluate the incidence of neoplasms of the colon, both metachronous or recurrent, in 322 patients. They were observed and resected for colorectal cancer between 1970 and 1988, with complete staging, and all agreed to be included in a follow-up program (median followup: 105 months). All the patients were submitted to colonoscopy once yearly for the first 5 years and then every 2 years. Anastomotic recurrence was observed in 22 of the 253 patients who underwent resection for rectal or sigmoid adenocarcinoma (8.7%). Sixteen of these patients were submitted to a second curative resection with a median survival of 35 months; the median survival was 6 months in the 6 patients who could not undergo this operation (p=0.0018). Metachronous adenomas of the residual colon were found in 24 patients and metachronous cancers in 5 at Stage A, according to Dukes' classification. In conclusion, a regular colonoscopic surveillance in patients resected for colorectal cancer is justified for early detection and potential resection of anastomotic recurrences, new primary cancer and adenomatous polyps. In patients resected for rectal or sigmoid carcinoma, a sigmoidoscopy should be performed every 6 months for the first 2 years for the early detection of anastomotic recurrences. In all cases, a colonoscopy should be performed every 5 years after surgery to detect metachronous lesions. Before surgery, a "clean colon" should always be established to detect possible synchronous lesions.

Endoscopic follow-up in oncological diseases of the gastrointestinal tract: the experience of the Regina Elena Cancer Institute.

In oncology, follow-up refers to the medical procedures aimed to control, over time, both patients at risk of developing cancer, or those already submitted to surgical treatments for neoplastic lesions. The usefulness of an endoscopic follow-up in oncological diseases of the gastrointestinal tract is still being debated and, in some cases, a variety of different protocols are often employed for the same disease. At Regina Elena Cancer Institute, after a critical review of our data and literature, we established and followed guidelines of endoscopic follow-up for patients both at risk and submitted to curative surgery for cancer.

C-MYB, serum P-53M, genetic instability, labeling index and endoscopic findings in patients with adenoma or colorectal cancer.

Structural alterations of c-myb proto-oncogenes and serum p53 mutant level, Mitomycin C-induced chromosomal aberrations and sister chromatid exchanges and proliferative activity of mucosa (H3-thymidine -labeling index LI) are often determined to obtain more information about the diagnosis and prognosis of neoplastic and preneoplastic lesions of the colon. The aim of this study was to evaluate the endoscopic findings of a 5 year follow-up in three groups of subjects (normal, adenoma or cancer patients) and to correlate these findings with the biological alterations in the same subjects between 1990 and 1993. We analyzed 200 subjects (118 Male and 82 Female), 78 normal subjects (group A), 60 patients with adenoma (group B) and 62 with carcinoma (group C). Data regarding endoscopic lesions was collected from June 1998 to December 2000 after a 5 year follow-up and correlated with the biological alterations in the same subjects between 1990--1993. We obtained endoscopic findings from 23/137 subjects (16.8%), 6/137 (4.4%) died from other causes and 108/137 (78.8 %) were negative for lesions. The percentage of disease after 5 years is not statistically different among the three groups (groups A, B and C). There was no statistically significant association between values of the labeling index, structural alterations of c-myb, p-53-M serum levels and chromosomal aberrations and endoscopic findings in the 5 year follow-up. We conclude that the biological markers considered are not able to stratify patients in terms of risk of progression to malignant disease.

[Efficacy of the disinfection of fiber endoscopes]. / Studio sulla efficacia della disinfezione di fibroendoscopi.

The validity of routine disinfection of gastrointestinal fibroscopes is reported. The Authors present their work based on 204 tests performed on gastroscopes and colonoscopes after manual disinfection performed by skilled nurses. All the instruments were kept in a 1:16 solution of glutaraldehyde-phenate for 10 minutes. Microbiological tests were performed half on sterile solution flushed on the outer part of the endoscope and half into the bioptic channel. Different groups of tests are reported. When strict asepsis was observed in handling the endoscopes all tests demonstrated to be sterile. When the endoscopes were handled as in usual routine, i.e. without sterile gloves and so on, 20% of the tests showed the presence of bacteria: these were only of types present in the environment. No real pathogens or antibiotic resistant strains were observed. The total disinfection procedure showed to be easy and quick to perform. No allergic or toxic reactions were observed. The importance of this procedure as a routine one in all endoscopy units is stressed considering also that literature data demonstrate the efficacy of glutaraldehyde-phenate against hepatitis and AIDS viruses.

[Colonic varices secondary to recurrent acute pancreatitis]. / Varici del colon secondarie a pancreatite acuta ricorrente.

Colonic varices are a rare finding, with variable clinical features. The authors describe the first case of colonic varices secondary to acute recurrent pancreatitis, and associated with colon cancer. There are about 70 reports of colonic varices; none of them is related to acute recurrent pancreatitis, whereas 52 are related to portal hypertension, and 9 are on a familial basis. Association with colon cancer is reported in one case, and seems to be occasional.

[The Lynch syndrome]. / La sindrome di Lynch.

Lynch syndrome is a peculiar disease, accounting for 5% of the total burden of colon cancer. Characteristics of this disease are autosomal dominant transmission, early onset, and frequent right colon localization. Diagnostic criteria, aimed to collaborative studies, are based on these features (so called Amsterdam criteria). Lynch syndrome has specific biomolecular features (microsatellite instability); mismatch repair genes have been identified as responsible of this syndrome. Lynch syndrome causes high risk for extracolonic malignancies, particularly for endometrial cancer, supposed to be related to mutation of hMSH2 gene. Another feature of Lynch syndrome tumours is better survival with respect to sporadic counterpart. Genetic test allows identifying the state of mutation carriers and selects the patients to submit to screening. Endoscopic screening has been demonstrated to reduce incidence of colorectal malignancies in this syndrome.