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Biomedical subjects

M T Chaumette

Publications and source records attributed to M T Chaumette.

At least 19 recordsLinked to original sources
PubMed2005

Metachronous gastric MALT lymphoma and early gastric cancer: is residual lymphoma a risk factor for the development of gastric carcinoma?

BACKGROUND: Helicobacter pylori plays a major role in the pathogenesis of primary gastric MALT lymphoma (GML) and gastric carcinoma. The occurrence of these two diseases metachronously in a same patient is a rare event. PATIENTS AND METHODS: Gastric biopsies and gastrectomy resection specimens of four patients who developed GML and early gastric cancer (EGC) were analysed by morphology, immunohistochemistry and molecular biology. RESULTS: Four patients (three males and one female; mean age 48 years) were diagnosed with GML. Helicobacter pylori infection was observed in three cases. Two patients had localized disease (stages IE and IIE, respectively) and were treated with H. pylori eradication therapy followed by an alkylating agent for one patient. Two patients had disseminated disease (stage IV), and were treated with an alkylating agent. Three cases were t(11;18) positive. All patients achieved initially complete lymphoma remission. Long-term endoscopic surveillance detected an EGC at the same location as the lymphoma in all patients at a mean time of 9.5 years (range 2.5-17 years) after lymphoma diagnosis. Gastrectomy specimens showed residual GML in all cases. CONCLUSION: Prolonged residual GML could constitute an additional risk factor for the development of gastric carcinoma. Long-term endoscopic surveillance is mandatory in patients treated conservatively for gastric MALT lymphoma.

Adult↗
PubMed2001

Galactomannan and polymerase chain reaction for the diagnosis of primary digestive aspergillosis in a patient with acute myeloid leukaemia.

Primary intestinal invasive aspergillosis is rarely reported in leukaemic patients. We describe a case of jejunal invasive aspergillosis in the setting of aplasia following chemotherapy for acute myeloid leukaemia. The diagnosis was confirmed by biopsy obtained during surgery and our polymerase chain reaction (PCR) test confirmed Aspergillus flavus as the fungus responsible. This patient had high levels of circulating galactomannan, an antigen secreted by Aspergillus sp., in serum. The ELISA test for galactomannan has been developed to improve the diagnosis of invasive aspergillosis but presents a 5-15% false positive rate. We suggest that some false positive results might be due to non-respiratory invasive aspergillosis, the usual localization of invasive aspergillosis. Our PCR test was also positive in serum. In case of positive results in serum with antigen and/or PCR tests without respiratory symptoms, the intestinal localizations should be investigated.

Aspergillosis↗
PubMed2001

Increased intestinal intra-epithelial T lymphocytes in primary glomerulonephritis: a role of oral tolerance breakdown in the pathophysiology of human primary glomerulonephritides?

BACKGROUND: There is increasing evidence that some organ-specific and generalized autoimmune diseases in humans might be related to a breakdown of oral tolerance. We explored this hypothesis in human primary glomerulonephritides. We prospectively counted intraepithelial T lymphocytes in the duodenal mucosa (as a marker of rupture of oral tolerance), together with IgA1 and IgA2 mucosal plasma cells, in patients with primary glomerulonephritides. METHODS: We investigated eight adults with immune-complex glomerulopathy (membranous nephropathy+membranoproliferative glomerulonephritis), 16 adults with an idiopathic nephrotic syndrome, and 25 adults with IgA nephropathy. Patients with glomerulonephritides were compared to two control groups: group 1 consisted of nine healthy adults; group 2 comprised five adults with coeliac disease before dietary gluten withdrawal or during a clinical relapse related to gluten ingestion. (The latter disease is associated with increased numbers of intraepithelial T lymphocytes, and a breakdown of oral tolerance to gliadins is involved in the pathogenesis of coeliac disease). Duodenal fibroscopy was performed under neuroleptanalgesia. Four to six endoscopic biopsy specimens were taken from the second duodenum. Intraepithelial T lymphocytes were blindly counted on paraffin sections stained with haematein-eosin-saffron (HES), within the epithelium of a villus in a zone with at least 100 cells. Mucosal IgA1 and IgA2 plasma cells were blindly counted in a mucosal tissue unit by using specific mouse monoclonal antibodies directed against IgA1 and IgA2, with alkaline phosphatase anti-alkaline phosphatase (APAAP) revelation. As values were not normally distributed, we used non-parametric analysis of variance with the Kruskal-Wallis test, and compared median values by using the non-parametric Mann-Whitney test. RESULTS: Intraepithelial T lymphocytes were significantly more abundant in patients with primary glomerulonephritides and coeliac disease than in healthy controls (P < 0.0001 in the Kruskal-Wallis test): healthy controls, median 11 (range 4.65-16); immune complex glomerulopathy, 27.45*** (15-93); idiopathic nephrotic syndrome, 16.5** (9-26.5); IgA nephropathy, 26.10*** (11.3-47.5); coeliac disease, 55*** (20-80) (*P <0.05; **P <0.01; ***P < 0.005, Mann-Whitney test). No difference was found in the number of duodenal IgA1 and IgA2 plasma cells between controls and patients with primary glomerulonephritides. IgA1 and IgA2 plasma cells were increased in patients with coeliac disease. CONCLUSION: The significant increase in intestinal intraepithelial T lymphocytes in primary glomerulonephritides suggests a pathophysiological role of oral tolerance breakdown.

Antigen-Antibody Complex↗
PubMed2001

Helicobacter pylori and gastric lymphoma: high seroprevalence of CagA in diffuse large B-cell lymphoma but not in low-grade lymphoma of mucosa-associated lymphoid tissue type.

OBJECTIVE: Gastric lymphoma of mucosa-associated lymphoid tissue (MALT) type is closely related to Helicobacter pylori (H. pylori) infection. In vitro studies have demonstrated H. pylori-induced B cell proliferation to be strain dependent. High prevalences of CagA protein and FldA protein have been reported in strains obtained from patients with gastric lymphoma of MALT type. The aims of the present study were to evaluate the prevalence of H. pylori infection and to search for antigenic particularities in 53 patients with primary gastric lymphoma in comparison with a group of infected patients with benign disease. METHODS: Of the 53 patients, 37 presented with low-grade lymphoma of MALT type (LGLM) and 16 with diffuse large B-cell lymphoma (DLBCL). They were compared to a group of 162 H. pylori-infected subjects comprising the control group: 111 had gastric or duodenal ulcer (GDU) and 51 nonulcer dyspepsia (NUD). Diagnosis of gastric lymphoma was established on histological examination of endoscopic specimens. Anti-H. pylori antibodies were assayed by third-generation ELISA. Western blot assay was used to detect antibodies against nine antigens (including CagA protein), which were recognized on the basis of their molecular weight. RESULTS: Of the 53 patients with gastric lymphoma, 45 were H. pylori-positive (85%): of these, 25 (56.5%) had anti-CagA antibodies. The prevalence of H. pylori seropositivity was 78% (29/37) in LGLM and 100% (16/16) in DLBCL. The prevalence of CagA seropositivity in H. pylori-positive patients was 44.8% (13/29) and 75% (12/16), respectively (p < 0.05). In comparison, the seroprevalence of CagA was 77.4% (86/111) in GDU patients and 43.1% (22/53) in NUD patients. The prevalence of antibodies to other antigenic proteins detected with Helicoblot 2.0 (19.5kd, 30kd, 35kd, VacA, HSPb, Urease A, and Urease B) did not differ among the groups except for 35kd protein, which was significantly higher (p < 0.01) in GDU than in NUD and in LGLM (76.6% vs 49% and 46.7%). CONCLUSION: These findings suggest that in patients who develop gastric lymphomas in response to H. pylori, virulent strains expressing CagA protein are preferentially associated with DLBCL.

Analysis of Variance↗
PubMed2000

Duodenal mucosa-associated lymphoid tissue lymphoma: treatment with oral cyclophosphamide.

Small cell mucosa-associated lymphoid tissue (MALT) lymphomas rarely affect the duodenum, and optimal treatment has not been defined. The aim of this case series was to determine the clinical features and outcome of duodenal MALT lymphoma in four patients (three men, one woman; median age 52 yr) treated with cyclophosphamide p.o. Initial manifestations were abdominal pain (n = 4), vomiting (n = 2), and an obstructive syndrome (n = 1). MALT lymphoma was diagnosed on the basis of endoscopic biopsies. It was localized in the duodenum in three cases and involved the entire small bowel in one case. Tumor infiltration was limited to the duodenal wall in one case and was associated with locoregional lymphadenopathy in three cases. The patients were graded EI (n = 1) and EII1 (n = 3), respectively, according to the Ann Arbor classification revised by Musshof. Cyclophosphamide, 100 mg daily, was administered p.o. for 18 months. Gastroscopy with biopsies, radiography of the small intestine and abdominal CT (CT) were performed every 6 months. Complete remission was defined by morphological and histological normalization, and partial remission as morphological normalization only. Follow-up lasted from 9 to 65 months. Three patients were in complete remission at 18 months: two relapsed after 2 yr and one was still in complete remission at 65 months. The patient with 9 months of follow-up was in complete remission at 6 months. The two patients who relapsed did not complain of symptoms, and no morphological abnormalities were seen. Relapse was diagnosed on histological grounds. Cyclophosphamide monotherapy p.o. thus seems well adapted to this slowly progressive disease, but it is unclear whether it should be resumed in the case of histological relapse or only in the case of symptomatic relapse. (Am J Gastroenterol 2000;95:536-539. (O 2000 by Am. Coll. of Gastroenterology)

Administration, Oral↗
PubMed1999

Correlations between p53-protein accumulation, serum antibodies and gene mutation in colorectal cancer.

Only half of colorectal-cancer patients elicit serum antibodies in response to intratumoral p53-gene mutations. Our study was designed to compare cellular events (p53-protein accumulation and gene mutations) with the presence of circulating anti-p53 antibodies (p53-Ab). Thirty-five colorectal-cancer patients were studied for their intratumoral p53-protein accumulation and circulating p53-Ab. Tumour DNA was analyzed for genomic mutations in a sub-set of 28 patients. In all, 18 tumours (51.4%) were positive by immunohistochemistry, and 17 tumour extracts were shown to contain "mutant" conformation p53 protein, 16 of them being were concordant by both methods. Of the 28 tumours tested by DGGE, 16 contained alterations in p53 exons 5 to 8 (57.1%). Of 12 tumours without detectable mutations, 10 were "mutant"-conformation-negative by immunohistochemistry and ELISA. Paradiploid tumors presented more frequently wild-type p53 genes and were significantly less frequently immunohistochemistry- or p53-Ab-positive than polyploid tumors. Circulating p53-Ab were detected in the serum of 11 patients (31%). In 9/11 cases, a gene mutation was found in the corresponding tumour. Three of four mutations in exon 8 and 3/3 mutations in exons 5-6 were associated with p53-Ab, in contrast with only 3/9 mutations in exon 7. We found good agreement in the detection of p53-gene alterations by different methods. However, our data suggest that all gene mutations may not be equivalent in term of immunogenicity.

Adenocarcinoma↗
PubMed1999

Seroprevalence of eight Helicobacter pylori antigens among 182 patients with peptic ulcer, MALT gastric lymphoma or non-ulcer dyspepsia. Higher rate of seroreactivity against CagA and 35-kDa antigens in patients with peptic ulcer originating from Europe and Africa.

BACKGROUND: It has been suggested that Helicobacter pylori may induce more or less severe gastroduodenal disease according to the strain virulence. DESIGN: We used Western blot to determine antigenic profiles associated with duodenal or gastric ulcer disease, MALT lymphoma and non-ulcer dyspepsia, and to identify geographical differences. METHODS: One hundred and eighty-two consecutive patients with H. pylori infection were studied. H. pylori infection was diagnosed by a rapid urease test or histological examination of gastric biopsy samples. Bacterial density and gastritis were assessed histologically by using the Sydney scoring system. Western blot was used to identify antibodies against eight antigens (CagA, VacA, urease A, heat shock protein B, and 19.5, 26.5, 30 and 35 kDa). Patients were questioned on their smoking habits and place of birth and childhood. RESULTS: There were 73 patients with duodenal ulcer, 30 with gastric ulcer, eight with erosive duodenitis, 17 with gastric MALT lymphoma and 54 with non-ulcer dyspepsia. Most (>85%) were seropositive for the heat shock protein B and 26.5-kDa antigens. The prevalence of the other antigens ranged from 45% (VacA) to 68% (urease B). The seroprevalence of CagA antigen was significantly higher (P < 0.01) in cases of gastroduodenal ulcer (84%) than non-ulcer dyspepsia (37%). Similarly, 35-kDa antigen reactivity was more frequent (P < 0.05) in duodenal ulcer patients (75%) than in those with non-ulcer dyspepsia (50%). The antigenic profiles associated with MALT gastric lymphoma and non-ulcer dyspepsia were similar. Multivariate analysis showed that only gastroduodenal ulcer was significantly associated with CagA. Gastroduodenal ulcer and a childhood spent in Africa were both associated with 35-kDa and combined CagA-35-kDa reactivity. CONCLUSIONS: This study confirms the strong seroprevalence of H. pylori CagA antigen and shows a high prevalence of the 35-kDa antigen in patients with gastroduodenal ulcer, especially those raised in Africa. There was no difference in the serological pattern between patients with non-ulcer dyspepsia and those with MALT lymphoma. Tests for antibodies to the CagA-35-kDa antigen combination might be used to select H. pylori-infected dyspeptic patients warranting treatment.

Africa↗
PubMed1998

[Comparison of quantifying Helicobacter pylori gastric infection by culture, histology and C13 urea breath test].

OBJECTIVES: In Helicobacter pylori infection, the bacterial burden may play a role in the pathogenesis of gastric or duodenal ulcerated lesions. It could also influence the results of antimicrobial therapy. No simple test has been validated to quantify Helicobacter pylori density. The aim of this study was to determine the value of histology and/or 13C-urea breath test to quantify the infection as compared with quantitative culture, taken as a reference method. PATIENTS AND METHODS: Biopsies samples were taken from the antrum at endoscopy in 72 patients. Thirty-seven patients with positive urease test at 20 minutes were enrolled in the study. Bacterial density was evaluated from biopsies by quantitative culture and semi-quantitative histological examination (score from 0 to 3). The bacterial density was evaluated as well by 13C-urea breath test from the proportion of 13CO2 in exhaled air (delta 13CO2) at 20, 40, and 60 minutes as compared with the basal level. RESULTS: The bacterial density, evaluated by quantitative culture ranged from 5 CFU to 110,000 CFU per mg of tissue. By histology, a score 1 was found in 5 patients, a score 2 in 17, and a score 3 in 15. delta of 13CO2 measured by 13C-urea breath test ranged from 0.2 to 117.5, from 0.2 to 102, and from 0.6 to 66.7 at 20, 40 and 60 minutes respectively. The quantity of bacteria measured by culture was not significantly higher for these with a score of 3 as compared with those with a pooled score of 1 and 2 (P < 0.05). No significant correlation was found between the results of quantitative culture and these of breath test. CONCLUSION: In practice, evaluation of bacterial burden by a histological score seems only accurate for the most severe density (score 3). The 13C-urea breath test does not allow a reliable quantitative evaluation.

Adult↗
PubMed1998

[Dysphagia revealing Crohn's disease].

Esophageal involvement in Crohn's disease is uncommon. We report here a case with pre-eminent esophageal symptoms and numerous tuberculoid granulomas at histopathological examination. This is an opportunity to review the differential diagnoses and to describe the clinical, endoscopic and histopathological features of this localisation.

Adolescent↗
PubMed1997

Endoscopic ultrasonography for the initial staging and follow-up in patients with low-grade gastric lymphoma of mucosa-associated lymphoid tissue treated medically.

BACKGROUND: Endoscopic ultrasonography is an appropriate procedure to assess the depth of tumoral infiltration in primary gastric lymphoma. The aims of the present study were to characterize the endoscopic ultrasonographic aspects of low-grade gastric lymphoma of mucosa-associated lymphoid tissue and to determine the value of this procedure in medical treatment assessment. METHODS: Between 1991 and 1996, 15 patients with low-grade gastric lymphoma of mucosa-associated lymphoid tissue were treated with oral cyclophosphamide and/or anti-Helicobacter pylori treatment. Endoscopic ultrasonography was carried out at the time of the diagnosis in all patients, 8 of whom (4 in complete remission and 4 with a stable or progressive disease) had at least one endoscopic ultrasonography examination within the treatment period (median follow-up 17 months). RESULTS: The initial procedure showed an increased gastric wall thickness from 6 to 12 mm in 8 patients, equal to 5 mm in 5 patients, and normal in 2 patients. The thickening was predominantly of the mucosa alone and/or the submucosa but never extended beyond the muscularis propria. No lymph node was found. Gastric wall thickness returned to normal in the 4 patients in complete remission and remained thick in 3 of the 4 patients with a stable or progressive disease. Of these 3 patients, at least one set of biopsy samples, carried out during follow-up, showed the absence of lymphoma, but histology performed subsequently found evidence of disease. CONCLUSIONS: Endoscopic ultrasonography differentiates superficial from infiltrative types of gastric lymphoma of mucosa-associated lymphoid tissue, which may have a prognostic significance and confirms remission or persistence of the disease with medical treatment during follow-up. When the gastric wall remains thick, even if histology is negative, repeated biopsies should be performed to detect evolving disease or relapse.

Adult↗
PubMed1997

Detection and monitoring of serum p53 antibodies in patients with colorectal cancer.

BACKGROUND: Detection of p53 antibodies in serum might be an effective indirect procedure to detect alterations of the p53 gene. AIMS: To assess the prevalence and the variation under treatment of p53 antibodies in patients with colorectal cancer. PATIENTS AND METHODS: Fifty four patients with colorectal cancer (26 men and 28 women, mean age 65, range 33-90 years) and 24 patients with non-malignant digestive disease were tested for p53 antibodies by enzyme linked immunosorbent assay (ELISA), and for the carcinoembryonic antigen and carbohydrate antigen 19.9. Immunohistochemical detection of p53 protein tumour overexpression was performed in 38 cases. RESULTS: Fourteen patients (26%) with colorectal cancer but none of those with non-malignant disease displayed p53 antibodies. Overexpression of p53 was shown by immunohistochemistry in 22 patients (58%), 10 of whom also had p53 antibodies. The antibodies were present in four patients with high carcinoembryonic antigen and three patients with high carbohydrate antigen 19.9 concentrations, but also in 10 patients (33.3%) with normal values of these markers. The ratio of p53 antibodies decreased in 11 of 13 patients after tumour resection. In two patients variations in p53 ratio strongly correlated with tumour relapse or progression. CONCLUSION: Testing for serum p53 antibodies constitutes a useful technique for assessing alterations in p53 and may help physicians to follow up patients with colorectal cancer.

Adenocarcinoma↗
PubMed1996

Identification of intracellular stages of Cyclospora species by light microscopy of thick sections using hematoxylin.

Cyclospora sp is a recently identified coccidia responsible for enteric infection in humans. Most reports have failed to detect this parasite in intestinal biopsies by light microscopy, although the different stages have been ultrastructurally described in jejunum enterocytes. Very recently, some investigators have reported the detection by light microscopy of parasitophorous vacuoles in intestinal biopsies; however, only transmission electron microscopy (TEM) could clearly identify the parasitic stages. To improve the histological diagnosis without using TEM, we have tested different staining methods in biopsies obtained from a patient infected by the human immunodeficiency virus who was shedding Cyclospora oocysts. Hematoxylin stain alone for 15 minutes on 5 micrometer-thick sections of duodenal biopsies was found to be the most efficient method for observing different stages of the parasite. In particular, the banana-shaped merozoites were visualized and appeared very similar to the human coccidia Isopora belli. This simple technique may be useful in diagnosing Cyclospora infection.

AIDS-Related Opportunistic Infections↗
PubMed1995

Efficacy of single-agent chemotherapy in low-grade B-cell mucosa-associated lymphoid tissue lymphoma with prominent gastric expression.

PURPOSE: The treatment of low-grade B-cell mucosa-associated lymphoid tissue (MALT) lymphoma with prominent gastric expression is controversial. Total gastrectomy has been proposed, but is associated with significant morbidity. The aim of this monocentric study was to assess the efficacy of continuous oral chemotherapy with a single alkylating agent. PATIENTS AND METHODS: Twenty-four consecutive patients, 13 men and 11 women, were studied. Their mean age was 51 years (range, 22 to 79). Low-grade B-cell MALT lymphoma was diagnosed by histologic and immunohistologic examination of endoscopic biopsies. Seventeen patients had stage I disease and seven stage IV disease, with lung and gastric involvement. Two of these seven patients also had bone marrow involvement. The alkylating agent (cyclophosphamide or chlorambucil) was administered orally and daily for periods of 12 to 24 months. RESULTS: The median follow-up time was 45 months (range, 14 months to 14 years). Complete remission was obtained in 18 patients (75%) after a median treatment duration of 12 months. Five patients relapsed; two of them were successfully re-treated, and one died of MALT lymphoma that had transformed into large-cell lymphoma. Chemotherapy was stopped after 24 months for six patients who only achieved a partial remission; two of them required further treatment for progressive disease (surgery for a small-bowel localization in one case and cyclophosphamide rechallenge in the other). Nine patients had neutropenia that required a reduced chemotherapy dosage. CONCLUSION: In low-grade MALT lymphoma with prominent gastric expression, continuous monochemotherapy may constitute an efficient alternative to gastrectomy, regardless of disease stage.

Administration, Oral↗
PubMed1993

Mucosal immunity in primary glomerulonephritis. III. Study of intestinal permeability.

To study the specificity of gut hyperpermeability in primary glomerulonephritis, we investigated intestinal permeability by means of 51Cr-EDTA testing in 20 healthy individuals and in 30 patients with Immunoglobulin A nephropathy (IgA GN), 25 with idiopathic nephrotic syndrome (INS) and 20 with immune complex glomerulonephritis (IC-GN; membranous+membranoproliferative glomerulonephritis). Gut permeability was statistically increased in each patient group versus the controls [controls: 2% (0.4-3.9); IgA GN: 3.25% (0.7-17.70); INS: 3.71% (0.82-10); IC-GN: 3.40% (0.30-16); results are median (range); p < 0.005, nonparametric Mann-Whitney test]. An increase in intestinal permeability exceeding the upper limit of control values (95th percentile) was observed in 36% of IgA GN, 60% of INS and 50% of IC-GN patients. We conclude that intestinal permeability is frequently increased in primary glomerulonephritis and may also be increased in types of glomerulonephritis other than IgA GN.

Adult↗