Biomedical subjects
F Potet
Publications and source records attributed to F Potet.
[Effect of prolonged treatment with proton pump inhibitors on serum gastrin levels and the fundus mucosa. Preliminary results].
OBJECTIVES: To evaluate the evolution of fundic argyrophil cell density and hyperplasia grading, fundic chronic gastritis grading and serum gastrin levels in patients treated with proton pump inhibitors. METHODS: Thirty-two patients treated with proton pump inhibitors for gastroesophageal reflux and/or duodenal ulcer were studied. No patient had a gastric ulcer. The studied parameters were serum gastrin levels, fundic argyrophil cell density, the degree of fundic argyrophil cell hyperplasia, the grade of fundic atrophic gastritis and the presence of Helicobacter pylori. The first point of the study was 7 months (range: 0-42 months) and the last point 33 months (range: 7-72 months) after the beginning of the treatment. RESULTS: Serum gastrin levels significantly increased with treatment. Fundic argyrophil cell density did not change significantly. In 3 patients (9%), serum gastrin levels were twice the normal upper limit. The highest serum gastrin levels (249 and 665 pg/mL) were noted in the 2 patients treated with the highest doses of proton pump inhibitors. Micronodular hyperplasia of the fundic argyrophil cells was observed in 2 patients treated with omeprazole 20 mg/d for 4 years and lansoprazole 90 mg/d for 6 years, respectively. Non active superficial chronic gastritis was noted in 2 patients. Serum gastrin levels were significantly correlated with cell densities. CONCLUSION: There were minor modifications of fundic argyrophil cell population and of gastrinaemia during the study period. They were not related to chronic atrophic gastritis. However, survey is mandatory in patients treated with high dose proton pump inhibitors, in those in whom gastrinaemia is elevated and when treatment duration is longer than 5 years.
[Malignant tumors of the colon with two components (carcinosarcoma). Report of a case].
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[In situ gene amplification on tissue sections (in situ PCR). A new technique for pathologists].
In situ polymerase chain reaction is a recent technique which combines the sensitivity of PCR reaction to intracellular localization of genomic sequences with the same specificity as in situ hybridization. This reaction is based on the in situ annealing and polymerisation of oligonucleotides complementary to nucleotides located at each side of the target DNA sequence to amplify. We describe the Hot Start PCR (DNA) and the Hot Start PCR after reverse transcription step (RNA). It allows to amplify some nucleic sequences to a high level, becoming easier to detect. The vizualisation can be realized by direct in situ PCR, the product obtained being directly identifiable by incorporation of labeled nucleotides or primers, or preferentially by indirect in situ PCR. In this case, the amplification is followed by in situ hybridization with labeled probes. This last procedure is more specific. Numerous controls are essential at each step of the technique for validating results.
[Cystic dystrophy on an aberrant duodenal pancreas. Apropos of a case].
Cystic dystrophy of the aberrant pancreas is a rare poorly understood condition which is difficult to diagnose and treat. The primary clinical signs are epigastralgia associated with poor general health and complications due to stenosis of the duodenum. Endoscopy gives the most information on tissue lesions and cystic formations in the duodenal mucosa. Although the condition is benign, and due to the lack of sufficient history in endoscopically treated cases, cystic dystrophy of the aberrant duodenal pancreas appears to require duodenopancreatectomy.
[Gastritis. Current point of view of the anatomo-pathologist].
Acute, granulomatous and chronic are the three main forms of gastritis. The discovery of Helicobacter pylori has stimulated a new detailed classification of gastritis. Having set out the various conventional histopathological classifications, the authors describe two newly recognized types of gastritis, lymphocytic gastritis and reactive gastritis. The authors also recall the earlier pathogenic classifications of gastritis, first initiated by Strickland and Mackay. Because of the problems related to these earlier classifications, the "Sydney system" has been developed. This system allows to simply pathologists' reports, by incorporating the morphological, topographical and etiological parameters of gastritis. Some of the advantages and disadvantages of the "Sydney system" are briefly discussed.
TP53 gene mutations and p53 protein immunoreactivity in malignant and premalignant Barrett's esophagus.
BACKGROUND/AIMS: Limited data are available regarding TP53 gene alterations in Barrett's esophagus. This study was undertaken to characterize TP53 mutations and p53 protein immunoreactivity in cancers and preinvasive lesions of Barrett's esophageal mucosa. METHODS: Seventeen Barrett's adenocarcinomas were examined by polymerase chain reaction amplification, denaturant gradient gel electrophoresis, and sequencing for the presence of TP53 mutations in exons 5-8. In 9 cases, Barrett's epithelium adjacent to the cancer was investigated. p53 protein immunoreactivity was studied with PAb 1801. RESULTS: Sixteen mutations were found in 15 adenocarcinomas, including 10 missense, 3 nonsense, 1 frameshift, and 2 mutations located within consensus splice donor and acceptor sequences. All nucleotide substitutions were transitions. Eight of the 12 transitions involving a GC base pair occurred within the context of a CpG dinucleotide. p53 immunostaining was present in all 10 cases with missense mutations and in 1 case without a detectable mutation. The surrounding Barrett's mucosa showed TP53 mutations identical to that observed in the carcinoma in only 3 of 5 specimens showing high-grade dysplasia. CONCLUSIONS: TP53 gene mutations and p53 protein immunostaining are present in a majority of Barrett's adenocarcinomas. Our results suggest that these mutations are involved at an early stage during malignant transformation of Barrett's esophagus.
Overexpression of the p53 tumor suppressor gene product in esophageal and gastric carcinomas.
PURPOSE: p53 protein has been reported as frequently overexpressed in esophageal and gastric carcinomas. However, the correlation between p53 protein expression and clinico-pathological features of the tumors is debated in this heterogeneous group of cancers. The aim of this study was to establish the prevalence of p53 protein overexpression in a series of resected esophageal squamous carcinomas (n = 78), adenocarcinomas developed on Barrett's esophagus (n = 20), adenocarcinomas of the cardia (n = 36), and adenocarcinomas of the antrum (n = 30), and to correlate this expression with the clinico-pathological and flow-cytometric characteristics of the tumors. METHODS: Immunohistochemical staining was performed on frozen sections with a monoclonal antibody directed against wild type and mutated p53 protein (Pab 1801). An adjacent frozen specimen was used for flow cytometric determination of the DNA-ploidy and S phase fraction. RESULTS: p53 protein nuclear expression was detected in 76% of esophageal squamous carcinomas, in 75% of adenocarcinomas developed in Barretts esophagus, in 56% of adenocarcinomas of the cardia, and in 27% of adenocarcinomas of the antrum. Only the number of positive adenocarcinomas of the antrum was significantly lower when compared to the other three types of tumors (p = 0.001). No significant correlation was observed between p53 protein expression and most of the clinico-pathological and flow-cytometric parameters (sex, age, tobacco smoking, chronic alcohol consumption, size of the tumor, grade of differentiation, depth of infiltration, presence of lymph node metastases, UICC stage, DNA-ploidy, S phase fraction). p53 protein expression was more frequent in Lauren's intestinal adenocarcinomas (67%) when compared to the diffuse type tumors (24%) (p = 0.002). CONCLUSIONS: Our results confirm that overexpression of p53 protein is a common feature of esophageal and gastric carcinomas. The high prevalence of p53 protein overexpression found in cardiac adenocarcinoma when compared to antral adenocarcinoma reinforces the hypothesis of distinct carcinogenetic mechanisms in these two cancers. In particular the lack of correlation between p53 expression and tumor stage suggests that p53 protein overexpression is an early event in these tumors.
p53 protein expression in Barrett's adenocarcinoma: a frequent event with no prognostic significance.
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Polymerase chain reaction assay for the detection of Helicobacter pylori in gastric biopsy specimens: comparison with culture, rapid urease test, and histopathological tests.
Ulcer recurrence is probably related to residual Helicobacter pylori (H pylori). Histological examination and culture are considered to be the most specific tests. CLO test is a rapid but less specific test, which is usually used as an alternative test to culture. The aim of this study was to investigate the efficiency of a simplified polymerase chain reaction (PCR) assay as a procedure for the diagnosis of gastric H pylori infection of patients. Biopsy specimens were obtained from antral mucosa of 58 patients at endoscopy and submitted to four tests for detection of H pylori. The bacteria were found in 53%, 43%, 48%, and 50% of patients according to the results of PCR, CLO test, culture, and histological examination. Twenty three patients had both negative histology and negative culture and PCR was negative in all of these. Thirteen patients were not classified because only histology or culture was positive and 10 of these had a positive PCR test. When the diagnosis of H pylori was established by agreement with both histology and culture or three positive tests out of four, 29 patients were H pylori positive (28 having had three positive tests and one displaying positive histology and culture), and 26 were negative, and three undetermined. PCR proved the most sensitive and specific test. These results suggest the simplified PCR assay may be a valuable test for the detection of H pylori.
Expression of c-erbB-2 oncogene product in Barrett's adenocarcinoma: pathological and prognostic correlations.
AIMS: To establish the prevalence of c-erbB-2 protein expression in a surgical series of Barrett's adenocarcinomas; and to correlate this expression with clinicopathological data and prognosis. METHODS: Sixty six surgical specimens of Barrett's adenocarcinomas were included in this retrospective study. Blocks of the tumour and of non-dysplastic Barrett's mucosa were stained with a polyclonal antibody specific for the intracytoplasmic domain of the c-erbB-2 protein. RESULTS: Seven of 66 tumours showed membrane staining for the c-erbB-2 protein. The non-dysplastic Barrett's mucosa was negative in all cases. There was no difference between c-erbB-2 positive and negative tumours with regard to mean age, sex ratio, percentage of alcohol misusers, percentage of smokers, tumour differentiation, depth of invasion, lymph node response, and proliferative activity, assessed by the percentage of tumour cells positive with the MIB-1 antibody directed against the Ki-67 antigen. All c-erb B2 positive tumours were of Lauren's intestinal type compared with negative c-erbB-2 tumours. Patients with c-erbB-2 positive tumours had a significantly poorer prognosis than patients with negative tumours. CONCLUSIONS: The prevalence of Barrett's adenocarcinomas expressing c-erbB-2 found in this study (11%) was similar to that observed in published series of gastric adenocarcinomas. c-erbB-2 protein expression could be an important prognostic indicator in Barrett's adenocarcinoma.
[Special issue on gastroenterology].
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[New types of chronic gastritis].
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[A case of polypoid solitary colonic plasmocytoma].
One case of polypoid solitary plasmacytoma in the sigmoid colon of a 60 year-old woman is presented. Plasmacytomas are rarely observed in the gastrointestinal tract and are especially uncommon in the côlon. Eight cases were published since 1972. They show a mean age of 46.3 years, a sex-ratio of 1/1, varying revealing symptoms, and no preferential colonic location. Two differential diagnosis must be discussed: an inflammatory pseudotumor, and a multiple myeloma related tumor. Multiple myeloma must be ruled out by a complete radiographic and biological research. Surgery is the only therapy described and seems to be efficient.
[Diagnostic difficulties in Barrett mucosa. Borderline forms of Barrett esophagus].
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[Reproducibility of histological criteria of dysplasia in Barrett mucosa].
Barrett's mucosa is a precancerous condition. The goal of endoscopic surveillance for patients with Barrett's esophagus is to grade dysplasia. The diagnosis of dysplasia is difficult. The aim of this study was to determine the observer variation in diagnosis of dysplasia. Thirty-seven biopsies selected from Barrett's mucosa reported as having dysplasia between 1987 and 1988 were reviewed by 4 pathologists. The biopsies were classified according to the method of Riddell, as no dysplasia, indefinite for dysplasia, low-grade dysplasia and high-grade dysplasia. Each pathologist reviewed the biopsies alone and then together. There was a total agreement between the 4 pathologists in 20 out of 37 biopsies (54%). The pair-wise agreement varied between 65 and 84%. It was 84% when the pathologists belonged to the same institution. Of 222 double reviews made by 6 pairs of pathologists (37 biopsies x 6 pairs of pathologists), there were 58 disagreements: 19 low grade/high grade dysplasia, 2 high grade/indefinite for dysplasia, 1 high grade/no dysplasia, 18 low grade/indefinite for dysplasia, 2 low grade/no dysplasia, 16 indefinite for dysplasia/no dysplasia. At the second review when the pathologists evaluated the biopsies together, the agreement was 92%; there were 3 biopsies on which there was total disagreement: twice between high grade and low grade dysplasia, once between low grade dysplasia, indefinite for dysplasia and no dysplasia. This retrospective study has shown that disagreement between pathologists was rarely found on the biopsies diagnosed as having high grade dysplasia, more often on those diagnosed as having low grade dysplasia or indefinite for dysplasia.(ABSTRACT TRUNCATED AT 250 WORDS)
[Are cancer of the cardia and cancer of Barrett esophagus different entities?].
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[Superficial cancer on Barrett esophagus].
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