Short segments of Barrett's epithelium and intestinal metaplasia in normal appearing oesophagogastric junctions: the same or two different entities?

BACKGROUND: Endoscopic diagnosis of short segments of Barrett's epithelium (SSBE)' is difficult and its meaning in terms of the presence of specialised columnar epithelium (SCE) has not been prospectively evaluated. AIMS: To evaluate the prevalence of SCE in patients with an endoscopic diagnosis of SSBE and in individuals with normal appearing oesophagogastric junctions, and to compare the clinical characteristics of these two groups. PATIENTS: Thirty one patients with an endoscopic diagnosis of short Barrett's oesophagus, less than 3 cm in length (group A), and 44 consecutive patients with normal appearing oesophagogastric junctions (group B). METHODS: Multiple biopsies were performed in suspicious epithelium and at the oesophagogastric junction in groups A and B, respectively. RESULTS: Age and sex distribution were similar in both groups. Reflux symptoms were more frequent in group A (p < 0.001), as were endoscopic and histological signs of oesophagitis (p < 0.001 and p = 0.001, respectively). SCE was found in 61.3% of group A patients compared with 25% in group B (p < 0.002), with men predominating in group A while women were more frequent in group B (p = 0.02). The differences in reflux symptoms and endoscopic/histological oesophagitis remained significant. CONCLUSIONS: These results show that endoscopic diagnosis of SSBE is associated with a high prevalence of SCE, significantly higher than that found in normal appearing oesophagogastric junctions. Differences between patients with SCE in the two groups suggest they may represent two different entities.

Absence of stimulation of poly(ADP-ribose) polymerase activity in patients predisposed to colon cancer.

Poly(ADP-ribose)polymerase (PARP) has been implicated in DNA repair mechanisms and the associated activity shown to markedly increase after DNA damage in carcinogen-treated cells. A defective DNA repair has been associated to the aetiology of human cancers. In order to assess the potential role of this enzyme in cellular response to DNA damage by gamma-radiation, we studied the activity of PARP in patients with familial adenomatous polyposis (FAP). We compared poly(ADP-ribose)polymerase activity by the rate of incorporation of radioactivity from [3H]adenine-NAD+ into acid-insoluble material in permeabilized leucocytes from FAP patients and healthy volunteers. Concomitantly, the intracellular levels of NAD+--the substrate for the PARP--and the reduced counterpart NADH were determined using an enzymatic cycling assay 30 min after [60Co] gamma-ray cells irradiation. Our results demonstrate that a marked stimulation of PARP activity is produced upon radiation of the cells from healthy subjects but not in the FAP leucocytes, which concomitantly show a marked decrease in total NAD-/NADH content. Our observations point to a role of PARP in the repair of the gamma-radiation-induced DNA lesions through a mechanism that is impaired in the cells from FAP patients genetically predisposed to colon cancer. The differences observed in PARP activation by gamma-radiation in patients and healthy individuals could reflect the importance of PARP activity dependent on treatment with gamma-rays. The absence of this response in FAP patients would seem to suggest a possible defect in the role of PARP in radiation-induced DNA repair in this cancer-prone disease.

[Genetic diagnosis of familial adenomatous polyposis: detection of APC gene mutations based on an in vitro synthetized protein]. / Diagnóstico genético da polipose adenomatosa familiar: detecção de mutações no gene APC com base na análise da proteína sintetizada in vitro.

Familial adenomatous polyposis of the colon (FAP) is a dominant autosomic disease in which virtually 100% of the affected individuals develop colorectal cancer before the age of forty. The gene responsible for this disease (APC gene) is mutated in the germ line of these patients. The genetic diagnosis of FAP was initially done using linkage analysis. Because 95% of the mutations in APC gene result in a stop codon which will originate a truncated protein, previous authors have proposed that the mutation analysis should be performed using an in vitro synthesized protein (IVSP) assay. In this study we searched for germinal mutations in exon 15 of the APC gene in subjects belonging to families with FAP, using the IVSP assay. Eighty individuals belonging to 23 families were included in this series. We started by studying exon 15 which encompasses 6500/8535 bp and which corresponds to 75% of the coding region. This exon was divided into four fragments, which were amplified by PCR and the product was used in a transcription/translation assay. Mutations resulting in a truncated protein were detected in 9/23 (39%) of the families. This corresponds to 20/42 (48%) of individuals analysed in these nine families. All the mutations were located in the 5' region of exon 15, with seven of them being in the first fragment and the remaining two in the same place of the second fragment. With the exception of two healthy individuals at risk, all the others with a detected mutation, already exhibited clinical manifestations. One of these two individuals was later confirmed to harbor colonic polyps, strengthening the diagnostic accuracy of this IVSP analysis. We also identified 10 other healthy subjects at risk with a negative genetic diagnosis, who were therefore removed from surveillance programs. In conclusion, our results show that IVSP analysis has a high sensitivity as a diagnostic tool and should be used as the first screening method to identify those individuals who have inherited the genetic defect, even before they have developed any symptoms. This will enable us to try new drugs which may potentially delay or prevent the development of colonic polyps.

p53 protein immunoexpression in esophageal squamous cell carcinoma and adjacent epithelium.

BACKGROUND: Immunoreactivity for p53 tumor suppressor gene product is commonly found in human malignancies and some premalignant lesions, but its role in cancer development and its value as a marker of tumor biologic behavior is still unclear. OBJECTIVES: This study was undertaken to assess p53 immunoexpression in esophageal squamous cell carcinoma and attempts to determine its correlation with morphological features associated with tumor behavior. METHODS: Immunohistochemical study was performed on archival paraffin-embedded tissue of 37 esophageal squamous cell carcinomas and respective adjacent mucosa. RESULTS: Twenty-one tumors (56.8%) demonstrated specific staining for p53. Sixteen areas of dysplasia were present in 14 out of the 35 cases. p53 positivity was found in one low-grade dysplasia and in six high-grade dysplasias. By univariate analysis, p53 immunoexpression correlated positively with local invasion (P = 0.01) and perineural spread (P = 0.04). Multivariate analysis with logistic regression showed that tumor invasion was the only factor that discriminated between p53 positive and p53 negative cases (OR: 15.6, P < 0.02). No relationship was found between p53 expression and tumor grade, DNA nuclear ploidy, and S-phase fraction. CONCLUSIONS: These data suggest that p53 dysfunction may be implicated in early, preinvasive, stages of esophageal cancer as well as in the tumor progression related to a more invasive phenotype.

Nutritional deficiencies in chronic alcoholics: relation to dietary intake and alcohol consumption.

OBJECTIVES: Relationships of nutritional status with ethanol consumption and diet were studied in 33 chronic alcoholics with no clinical or laboratory evidence of liver disease. METHODS: Nutritional assessment included subjective global assessment, weight-height index, body mass index, and serum albumin measurements. Dietary intake included estimates of daily intake of substrates, folic acid, vitamins B1, B5, B6, and B12. Circulating concentrations of folate, pyridoxal-phosphate and vitamin B12 were evaluated as well. RESULTS: Only 18.1% of patients were considered malnourished, with body mass indices lower than those with an average or good nutritional status (p < 0.0001). Body weight was under 90% of the ideal in 8/33 (24%) patients. Serum albumin values were within normal range in all patients. In terms of calories provided by nonalcoholic substrates, protein, or vitamin intake, we observed no differences between well and poorly nourished individuals. However, malnourished alcoholics consumed significantly more ethanol (p = 0.01) and an inverse correlation was found between ethanol intake and weight-height index (r = -0.35; p = 0.03). Low circulating concentrations of pyridoxal-phosphate and red blood cell folate were found in 51.5% and 60.6% of alcoholics, respectively. These were not correlated with vitamin dietary intake or ethanol consumption, but there was a trend toward malnourished patients to present lower concentrations of red blood cell folate (p = 0.13). CONCLUSIONS: Although over malnutrition is infrequent in this group of chronic alcoholics, specific vitamin deficiencies are present in a substantial proportion of patients and are more likely related to alcohol consumption.

DNA hypomethylation and proliferative activity are increased in the rectal mucosa of patients with long-standing ulcerative colitis.

BACKGROUND: DNA methylation and DNA cytometric parameters were evaluated in the rectal mucosa from patients with extensive and long-standing ulcerative colitis. METHODS: Twenty-six patients with extensive disease for more than 7 years and 11 healthy controls were included. Global DNA methylation was assessed as the capacity of the DNA test to incorporate [3H]methyl groups from [3H]-S-adenosyl-methionine in the presence of Sss1 methylase. A higher incorporation reflects a lower state of intrinsic methylation. DNA ploidy, S-phase fraction, and proliferative index (PI = S + G2M) of the cell cycle were analyzed by flow cytometry. RESULTS: Incorporation of the [3H]methyl groups into DNA was 10-fold higher in patients compared with controls (P < 0.001) and was significantly higher in patients with histologically active disease (P = 0.02). With regard to flow cytometry, all samples showed a diploid pattern, but S-phase fraction and the proliferative index values were significantly increased in patients compared with controls (P = 0.0007 and P = 0.003, respectively). A positive correlation was found between S-phase fraction and proliferative index and the number of exacerbations of the disease (P < 0.005), and there was a trend among those patients who had disease for longer than 20 years to present with increased cellular proliferation compared with those with a shorter evolution of disease (P > 0.05). CONCLUSIONS: DNA hypomethylation and proliferative activity are increased in this group of patients, supporting the concept that their colonic mucosa undergoes epigenetic and kinetic changes that might predispose these individuals to develop colorectal neoplasms. However, it cannot be ruled out that these markers solely reflect hyperproliferation associated with active inflammation.

Tuberculous mesenteric lymphadenitis mimicking pancreatic carcinoma.

Tuberculous mesenteric lymphadenitis is a rare clinical entity and non-surgical diagnosis of this condition remains a challenge. A 38-year-old Indian woman presented with a six-week history of epigastric pain, low-grade fever and anorexia. Upper endoscopy showed a gastric ulcer of the posterior wall of the stomach. On CT scan there was a 8 cm abdominal mass involving the pancreatic body and tail and the endoscopic ultrasonography was also compatible with a cystic pancreatic tumor which had eroded into the stomach. An exploratory laparotomy was performed and the diagnosis of tuberculous mesenteric lymphadenitis was confirmed by bacteriological and histological examinations. Medical therapy was started after surgery. At 18 months she is asymptomatic and abdominal CT scan is normal. Tuberculosis of mesenteric lymph nodes usually raises serious diagnostic problems. A high grade of suspicion is necessary in order to perform a pre-operative diagnosis.

Hyperhomocysteinemia in chronic alcoholism: correlation with folate, vitamin B-12, and vitamin B-6 status.

Serum homocysteine concentrations have been shown to be a sensitive functional indicator of intracellular folate, vitamin B-12, and vitamin B-6 status. Chronic alcoholism is known to interfere with one-carbon metabolism, for which the above vitamins serve as coenzymes. In the present study, these vitamins were assessed in 32 chronic alcoholics and 31 healthy volunteers by measuring blood vitamin concentrations as well as serum homocysteine concentrations. In chronic alcoholics, serum pyridoxal 5'-phosphate and red blood cell folate concentrations were significantly lower than in the control subjects (P < 0.001 and P = 0.008, respectively). Mean serum homocysteine was twice as high in chronic alcoholics than in nondrinkers (P < 0.001). Beer consumers had significantly lower concentrations of homocysteine compared with drinkers of wine or spirits (P = 0.05). These results suggest that by interfering with folate or vitamin B-6 metabolism, chronic alcohol intake may impair the disposal of homocysteine through the transmethylation or transsulfuration pathways.

High prevalence of human papillomavirus in squamous cell carcinoma and matched normal esophageal mucosa: assessment by polymerase chain reaction.

BACKGROUND: Studies using DNA technology have reported the presence of human papillomavirus (HPV) DNA in esophageal carcinomas, suggesting that it could play a role in the pathogenesis of this tumor. In the present study, in addition to DNA from neoplasms, normal mucosa was screened for viral DNA, assuming that this would increase HPV detection substantially. METHODS: Seventeen patients with esophageal carcinoma and 10 control subjects were studied. In 8 of the patients, normal mucosa was also available. Polymerase chain reaction (PCR) was performed using primers for the E6 region of HPV-16 and HPV-18. Koilocytosis, a commonly accepted histopathologic marker of viral infection, was studied, and results were correlated with PCR findings. RESULTS: DNA from neoplastic lesions was positive for HPV-16 and HPV-18 in 8 of 16 (50%) and in 3 of 16 (18.8%), respectively. When tumor tissue and normal mucosa were available, PCR results were 3 of 8 (37.5%), 5 of 8 (62.5%), and 8 of 8 (100%) for HPV-16, in tumor, normal mucosa, and both. For HPV-18, results were 0 of 8 (0%), 5 of 8 (62.5%), and 5 of 8 (62.5%), respectively. In comparison with tumor samples, positivity in normal mucosa was increased for HPV-18 and for both viral genotypes (P = 0.01). No amplification was obtained in the control group. Koilocytosis was present in 33% of the cases. CONCLUSIONS: These results suggested a high prevalence of HPV in esophageal carcinoma. The detection rate is significantly higher in normal mucosa specimens, suggesting that infection probably antedates tumor development. Koilocytosis was substantially less sensitive than PCR.

Calcium regulation of colonic crypt cell kinetics: evidence for a direct effect in mice.

BACKGROUND & AIMS: Oral calcium supplementation is believed to decrease colonic hyperproliferation through neutralization of fatty acids and bile acids. In the present study, the effect of oral calcium, given with low-fat diets, in the early stages of colorectal carcinogenesis is evaluated. METHODS: In experiment A, mice received normal or low-calcium diets and were killed at 25 weeks. In experiment B, mice were fed the same diets but were submitted to six weekly injections of dimethylhydrazine and were killed at 10, 16, and 21 weeks. Cell proliferation was evaluated using bromodeoxyuridine immunohistochemistry. RESULTS: In experiment A, mice fed low-calcium diets showed a significant upward shift of the proliferative compartment (P = 0.04) (phase 2 defect) in the absence of hyperproliferation. In experiment B, besides a phase 2 defect, dimethylhydrazine-induced hyperproliferation was also significantly enhanced in animals fed low-calcium diets (phase 1 defect) as shown by an increased number of labeled cells per column and total labeling index (P = 0.01). CONCLUSIONS: Low-calcium diets induce an upward shift of the main proliferative compartment, which reflects an increased risk for malignant transformation. This effect was observed with a low-fat diet, suggesting a direct mechanism, rather than the usual indirect one, documented with high-fat diets.

DNA methylation as an intermediate biomarker in colorectal cancer: modulation by folic acid supplementation.

Several studies have suggested that DNA hypomethylation is an early step in colorectal carcinogenesis. However, it is not clear at which stage in carcinogenesis this hypomethylation occurs, what promotes it, the extent to which it can be reversed and the consequences of such reversal in affecting tumour development. In an attempt to address some of these questions, we studied three groups of subjects with similar age and gender distributions: a group of 12 patients with colorectal carcinomas; a group of 12 patients with colorectal adenomas; and a group of eight healthy control subjects. Two experimental protocols were employed. In the first protocol, intrinsic DNA methylation was evaluated in neoplastic and in normal-appearing rectal mucosa of patients with colonic carcinomas or adenomas, compared with a group of healthy controls. In the second protocol, we examined, in a prospective and controlled fashion, the effect of folic acid supplementation (10 mg/day) on the degree of DNA methylation of rectal mucosa from those same patients after removal of the neoplasms. The degree of intrinsic DNA methylation was assessed on the basis of the capacity of the DNA isolates to serve as methyl acceptors in in vitro incubations that contained DNA methylase and [3H-methyl] S-adenosylmethionine. Intrinsic DNA methylation was significantly lower in carcinomas than in adenomas (P < 0.005). In addition, normal-appearing rectal mucosa from patients with carcinomas was significantly less methylated than in healthy controls (P < 0.005); the mean value found in the latter was also greater than the value observed in patients with adenomas, but not significantly so (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Helicobacter pylori antibodies prevalence and gastric adenocarcinoma in Portugal: report of a case-control study.

Evidence from large cohort studies has established an increased risk of gastric cancer for individuals infected with Helicobacter pylori (HP). In low incidence countries, like the United Kingdom and Sweden, case-control studies suggested that the prevalence of anti-HP antibodies in gastric cancer patients (at the time of cancer diagnosis) is greater than in control populations. We present results from a case-control study of the prevalence of IgG anti-HP antibodies in gastric cancer patients and a control population in a country with a high incidence of gastric cancer. Sera were studied from 80 gastric cancer patients (GC group) admitted consecutively to our department in 1990/91, and from 80 controls (CT group) matched by age and sex. IgG anti-HP was determined by ELISA. Patients' files were reviewed for evidence of previous diagnosis of peptic ulcer, gastric surgery, tumor localization and histopathological classification. Controls were submitted to a questionnaire for past history of peptic ulcer and gastric surgery. Positive results for anti-HP were: gastric cancer patients, 70.0%; control group, 81.5% (NS). However, the median optical densities (OD, a measure of antibody concentration) were significantly lower in the gastric cancer group than in controls: gastric cancer patients, 0.720 +/- 0.424 OD; control group, 0.906 +/- 0.443 OD (P = 0.004). There were no differences concerning past history of peptic ulcer or surgery. The proportion of positives for cancer of the cardia (66.7%) was lower than for the other tumour localizations (70.4%) (NS). Anti-HP positivity was lower in patients with gastric cancer associated with intestinal metaplasia than in controls (P = 0.14).(ABSTRACT TRUNCATED AT 250 WORDS)

[Value of congenital hypertrophy of the retinal pigment epithelium as diagnostic marker in familial adenomatous polyposis]. / Valor da hipertrofia congénita do epitélio pigmentar da retina como marcador diagnóstico na polipose adenomatosa familiar.

Familial Adenomatous Polyposis (FAP) is a dominant autosomic disease characterized by the development of hundreds to thousands of colonic adenomatous polyps. Affected patients have a 100% risk of colon cancer development if they are not submitted to a prophylactic colectomy. Identification of carriers depends on the detection of colonic polyps, and endoscopic surveillance must be offered to all descendents, including healthy individuals. Congenital hypertrophy of the retinal pigment epithelium (CHRPE) has been suggested to have a correlation with FAP trait, even before colonic polyp development. The objective of this study is to evaluate CHRPE as a diagnostic marker in FAP patients and descendents. CHRPE was studied in 26 members of 7 FAP families, using direct and indirect ophthalmoscopy, biomicroscopy and retinography. It was found in 62.5% of patients and in 10% of the descendents at risk. Two families did not show signs of CHRPE. Affected members in the remaining families, had positive examinations in 83.3% (two affected members were negative). These results suggest that CHRPE is an important diagnostic tool to identify FAP patients in those families which express the marker. To those descendents who have negative examinations, whether they belong to positive or negative CHRPE families, identification of FAP trait depends on endoscopic surveillance in order to detect colonic polyps.