Detection of mutations in mismatch repair genes in Portuguese families with hereditary non-polyposis colorectal cancer (HNPCC) by a multi-method approach.

Mutation searching was performed in the hMSH2 and hMLH1 genes in 20 Portuguese families representing 124 registered affected individuals. Of the 20, 16 fulfilled the classic 'Amsterdam' criteria for HNPCC, whereas the remaining four families satisfied a modified set of criteria. These criteria required a CRC diagnosed before age 50 years and cancers diagnosed in two other relatives within the HNPCC spectrum. A multi-method approach was performed using the protein truncation test (PTT), single strand conformation polymorphism (SSCP) with two different sets of conditions, heteroduplex analysis (HA) and denaturing gradient gel electrophoresis (DGGE). Putative phenotype-genotype correlations were also explored. Ten different germline mutations were identified. Six of these were found in hMLH1 in seven families and four in hMSH2 in four families. SSCP and DGGE had the highest diagnostic yields with the percentage of variants detected above 67% and together HA and PTT had the lowest. No single technique detected all variants. Trends for the absence of extracolonic manifestations were observed in families carrying hMLH1 germline mutations (four of seven in hMLH1 vs one of four in hMSH2). Most of the families with rectal cancer were associated with hMLH1 (six of seven in hMLH1 vs two of four in hMSH2). A multi-technique approach is necessary to identify a high percentage of germline mutations. Seven novel mutations were found in this Portuguese population.

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.

Non-goblet cell population of Barrett's esophagus: an immunohistochemical demonstration of intestinal differentiation.

Barrett's esophagus develops with the following 2 distinct types of lining mucosa: with and without specialized intestinal metaplasia (SIM). Goblet cells found only in SIM areas identify an intestinal phenotype, recognized as the histological hallmark diagnosing Barrett's metaplasia, and selecting high-risk patients for endoscopic surveillance. The columnar non-goblet cells are the major component of the heterogeneous Barrett's metaplastic cell population and are present in areas either with or without SIM. Their significance in the differentiation of columnar-lined esophagus, and their relationship to malignancy, is still unclear. This immunohistochemical study used two markers of enterocytic differentiation, to explore the intestinal phenotype of the non-goblet cell population of Barrett's epithelium and Barrett's-associated adenocarcinoma cells. Sucrase-isomaltase (SI) and dipeptidilpeptidase IV (DPP) immunoexpression was assessed in paraffin-embedded samples of 12 surgical specimens containing Barrett's esophageal mucosa in association with adenocarcinoma/high grade dysplasia. Ileal mucosa and mucosa from normal gastric and esophageal segments of the surgical specimen were used as positive and negative controls, respectively. SI and DPP were expressed by the neoplastic cells and the columnar non-goblet, being negative in goblet cells. The localization of the enzymes was predominantly apical for SI and cytoplasmatic for DPP. There was immunoreactivity for SI in 58.3% of the carcinomas and in 66.6% of Barrett's mucosa, with equal frequency in areas with and without SIM. DPP was identified in 66.6% of the carcinomas, in 50% of the cases of Barrett's metaplasia with SIM, and in 75% of those without SIM. The columnar non-goblet cell components of Barrett's metaplasia contain small intestine enzymes in the areas either with or without SIM, which suggests that they identify an "incomplete form" of intestinal metaplasia. The demonstration that the two enzymes, SI and DPP, are produced by the columnar non-goblet cell metaplastic population and by the neoplastic cells of the associated adenocarcinoma, indicates that, in addition to the goblet cells, the non-goblet elements may also be involved in the malignant transformation of Barrett's esophagus.

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)

Red wine consumption and gastric cancer in Portugal: a case-control study.

The present case-control study was designed mainly to estimate the risk of gastric cancer associated with consumption of alcoholic beverages. Seventy-four cases were selected from patients undergoing endoscopy with a histologically confirmed diagnosis of gastric cancer and matched by age and sex to a pool of controls (193) from three different sources, at the same hospital ward. After adjustment for several confounders, consumption of more than one bottle of red wine per day 20 years prior to the interview showed an odds ratio (OR) = 2.61 (P = 0.049), with a dose-response relationship increasing from 1.36 for those consuming less than one glass of wine per meal, up to 3.67 if the daily consumption exceeded one bottle of red wine. Other statistically significant determinants of the disease occurrence were low education level (OR = 4.33; P = 0.0008) and low social class (OR = 2.77; P = 0.016), as well as the regular practice of preserving food by smoke at home (OR = 1.91; P = 0.032).

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)

Enterocytic columnar non-goblet cells of Barrett's esophagus--an immunohistochemical demonstration of association with malignant evolution.

Barrett's epithelium (BE), the esophageal columnar-lining with intestinal differentiation, is a premalignant condition predisposing to adenocarcinoma. Columnar cells are the prevalent element of BE, but the hallmark of intestinal differentiation is the goblet population that defines the specialised columnar epithelium (SCE). We have demonstrated that columnar cells adjacent to Barrett's adenocarcinoma (BA) exhibit enterocytic features in areas with and without SCE. Nevertheless, the relationship between malignancy and the presence of these elements is not established. To investigate whether intestinal differentiated cells, other than goblet cells, are associated to neoplasia we compared the prevalence of enterocytic features in columnar elements with and without associated BA through the use of sucrase-isomaltase (SI) immunoreactivity in 31 columnar esophageal segments (CLES) and 12 BA. In metaplasia, SI was only expressed at the columnar cells. Apical staining was exclusive of CLES with SCE. SI was present at the cytoplasm in 22.2% of CLES without SCE. Apical SI occurred in BE with and without carcinoma, similarly in areas with and without SCE (p = 0.11 and p = 0.50, respectively). In areas with SCE, columnar cells with apical SI were more frequent in cases of BE adjacent to carcinoma than in cases without neoplasia but the difference did not reach significance (p = 0.053). In areas without SCE, apical SI was significantly (p = 0.01) more frequent in cases with carcinoma. Apical SI was equally found in neoplastic as in metaplastic areas, with and without SCE, (p = 0.07 and p = 0.40, respectively). In conclusion this study on the frequency of SI on CLES with and without neoplasia demonstrated that additionally to SCE, metaplastic enterocytic cells are also associated with malignancy. It also confirmed that the presence of intestinal features are underestimated if only goblet elements are used for its identification, reinforcing the utility of the immunohistochemical recognition of enterocytic characteristics for establishing the diagnosis of BE.

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.

[Affinity constant in radioimmunoassay]. / Constante de Afinidade em Radioimunoanalise.

Values for the affinity constant were determined, in three kits, for seric gastrin, following the Scatchard plot and Michaelis-Menten representation. The determination of the affinity constant, K, is of great value for it defines the antigen-antibody complex stability and it gives information about some aspects of the analysis system: sensitivity and antibody saturation.

[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.

[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.

Gastric and intestinal differentiation in Barrett's metaplasia and associated adenocarcinoma.

Intestinal metaplasia is a prerequisite criterion for the diagnosis of Barrett's metaplasia and the sole columnar esophageal lining associated with malignancy. It is recognized by the presence of goblet cells, but columnar non-goblet elements, producing gastric or intestinal proteins, are the prevalent cell population. The cellular heterogeneity of Barrett's metaplasia is well documented but the relationship between the distinct cell subtypes and neoplasia is unclear. Our aim was to clarify the relationship between the different metaplastic populations and malignancy in order to investigate putative markers for risk stratification of Barrett's patients. We studied 46 columnar-lined esophageal segments, 15 with associated adenocarcinoma. The presence of the gastric, MUC5AC and MUC6, and the intestinal, MUC2, proteins was evaluated in metaplastic (columnar and goblet) and neoplastic cells. In neoplasia MUC5AC and MUC6 were detected in 100% and 86.6% of the cases, respectively. In metaplasia there were no differences in MUC5AC and MUC6 immunoreactivity, between cases with and without associated neoplasia, except for goblet elements producing MUC6 that were exclusive of metaplasia adjacent to adenocarcinoma (P < 0.05). MUC2 was present in 86.6% of the neoplasia. In metaplasia it was restricted to Barrett's cases and was more frequent in areas with intestinal metaplasia. Columnar-lined esophagus without intestinal metaplasia did not express MUC2. Our study suggests a relationship between the metaplastic population with gastric phenotype and malignancy, and points to the involvement of columnar as well as goblet elements in tumorigenesis. The association between goblet cells aberrantly producing MUC6 and the presence of neoplasia suggests they may be useful for risk stratification.

Immunohistochemical detection of mismatch repair gene proteins as a useful tool for the identification of colorectal carcinoma with the mutator phenotype.

There are two well-defined pathways for colorectal carcinogenesis, the suppressor and the mutator pathways. The latter is characteristic of hereditary non-polyposis colorectal cancer (HNPCC), but can also be found in a subset of sporadic colorectal cancer (SCC) possessing distinctive clinical and pathological features, namely early age of onset, location in the right colon, poor differentiation, and a predominant mucinous component. This mutator pathway results from inactivation of mismatch repair (MMR) genes, namely MSH2 and MLH1. The aim of this study was to ascertain if abnormal MMR protein gene expression is a good indicator for identifying tumours from the mutator pathway. Seventy-six cases of SCC were studied by immunohistochemistry using two monoclonal mouse antibodies that react against MSH2 and MLH1 protein gene products. Immunoexpression was assessed both in tumour and in non-neoplastic, adjacent and distant mucosa. Microsatellite instability (MSI) was detected by evaluating the length of poly(CA) repeated sequences at seven loci, or by the detection of small unstable alleles in a poly(A) repeat - BAT-26. Except for BAT-26, in which only tumour DNA was used, MSI analysis was performed in both tumour and normal mucosal DNA. MSI was classified as high (MSI-H), low (MSI-L) or stable (MSS). Abnormal protein expression was found in 9/76 (12%) tumours. Immunohistochemistry for hmlh1 and hmsh2 detected 75% of MSI-H. There was also a highly significant correlation between the observed immunoexpression and several clinical and pathological characteristics described as the phenotypic profile of the mutator pathway, such as right-sided location (p=0.003), mucin production (p=0.008), and a peritumoural lymphoid infiltrate (p=0.009). Non-neoplastic adjacent mucosa showed normal hMSH2 expression in all cases, but in ten cases there was no hMLH1 expression in this transitional mucosa, which is known to display an alterated mucin pattern and a high proliferative rate. These results demonstrated a good correlation between hMLH1 and hMSH2 gene immunoexpression and the clinico-pathological features characteristic of the mutator phenotype and support the use of this method as a rapid and efficient way to detect tumours arising from this pathway.

Flow cytometric DNA ploidy and S-phase fraction correlate with histopathologic indicators of tumor behavior in colorectal carcinoma.

BACKGROUND: The clinical behavior of colorectal carcinoma is highly variable without reliable predictive biomarkers. Previous reports have shown that flow cytometric DNA analysis may provide valuable prognostic information in these tumors. PURPOSE AND METHODS: This study evaluates the DNA ploidy and the S-phase fraction (SPF) on frozen samples obtained from 61 patients with colorectal carcinoma by using flow cytometry, and it correlates the data with histopathologic features known to affect disease prognosis. Tumors were classified using the World Health Organization's histologic criteria and were staged according the American Joint Committee on Cancer's classification system. Grade of the neoplasm, vascular invasion, and perineural tumor spread were evaluated in every case. RESULTS: Fifty-nine percent of tumors were aneuploid and showed statistically significant higher S-phase values than diploid tumors (22.5 vs. 11.2 percent; P < 0.00001). Mean SPF of the whole series was 17.9 (range, 4.2-44.2) percent. A statistically significant association was found between SPF values and histologic grade (P < 0.0016), nodal status (P < 0.0007), distant metastasis (P < 0.0001), tumor stage (P < 0.0001), venous invasion (P < 0.0002), and lymphatic permeation (P < 0.01) but not with perineural growth and infiltration of the neoplasm through the bowel wall (T). DNA ploidy correlated positively with tumor stage (P < 0.03), and the association between aneuploidy and advanced stages of the disease was statistically significant. CONCLUSIONS: These findings showed that flow cytometric DNA ploidy and SPF, evaluated in fresh samples, are potentially useful parameters to estimate colorectal carcinoma biopathology. Aneuploidy and high replicative neoplastic activity correlated with histopathologic features that are commonly associated with the prognosis of colorectal carcinoma, being SPF-related to disease dissemination and, therefore, an indicator of clinical relevance.

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.

The Muir-Torre syndrome: a rare variant of hereditary nonpolyposis colorectal cancer associated with hMSH2 mutation.

The Muir-Torre syndrome is a rare autosomal dominant disorder characterized by the association of visceral malignancies with typical skin lesions. This syndrome is now considered a subtype of the more common hereditary nonpolyposis colorectal cancer syndrome (HNPCC). This last condition has been ascribed to mutations in four mismatch repair genes, and similar mutations, mostly located at hMSH2 gene, are now being described in some Muir-Torre patients. We describe the case of a 64-yr-old woman with no family history of colorectal cancer, who developed two visceral malignancies belonging to the usual spectrum of hereditary nonpolyposis colorectal cancer (colon and stomach), beginning at age 41. She additionally developed several skin tumors, including multiple keratoacanthomas, thus fulfilling Muir-Torre diagnostic criteria. Because of her cutaneous phenotype, she was screened for DNA mismatch repair gene mutations by in vitro synthetized protein assay (IVSP) and a truncating mutation was identified at hMSH2. We further discuss the clinical significance of the Muir-Torre phenotype, the association of this syndrome with hMSH2 mutations and the important implications of genetic diagnosis for the patient and her offspring.

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.

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.

Recurrent columnar-lined esophageal segments--study of the phenotypic characteristics using intestinal markers.

Barrett's metaplasia is recognized by specialized columnar epithelium on the distal esophagus. The events involved in the transformation from squamous to Barrett's epithelium remain unclear. The present study describes the characteristics observed during the recurrence of four cases of columnar-lined esophagus. Red velvet, gastric-like, esophageal mucosa was observed to develop above the anastomosis during follow-up of four patients submitted to surgery for esophageal and junctional adenocarcinoma. The areas of recurrence were associated with reflux symptoms and inflammation, with ulceration in two cases. Biopsies from the upper gastrointestinal endoscopies were examined histologically using periodic acid-Schiff/Alcian blue to detect acid mucins and a monoclonal antibody raised against the enterocytic enzyme sucrase-isomaltase. In all cases the recurrent columnar-lined segments displayed intestinal features recognized morphologically, histochemically, and/or immunohistochemically. There was no evidence of specialized columnar epithelium in three cases. The fourth patient developed specialized columnar epithelium during the tenth year of surveillance. The presence of AB-positive columnar cells was a frequent and early event. Columnar cells with unequivocal apical sucrase-isomaltase were observed only in association with specialized columnar epithelium. Four conclusions were reached: that the development of columnar-lined mucosa without specialized columnar epithelium may be the earliest event in Barrett's metaplasia; that histochemistry is a useful method of recognizing a population with cryptic intestinal features; that acid mucin secretion precedes the production of enterocytic enzymes by columnar cells; and that a cell population with enterocytic differentiation, as assessed by sucrase-isomaltase expression, is associated with the development of specialized columnar epithelium. These characteristics of Barrett's esophagus development are clinically relevant as they suggest that patients with columnar-lined esophagus without specialized columnar epithelium may acquire 'true' intestinal phenotype, justifying them being considered as high- risk patients.

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.