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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
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↗
PubMed1992

Protein-losing enteropathy in gastrointestinal sarcoidosis associated with malignant lymphoma.

A patient with disseminated gastrointestinal sarcoidosis and non-Hodgkin's malignant lymphoma developed diarrhea and polyadenopathy. Laboratory analysis revealed the presence of protein-losing enteropathy without biological signs of malabsorption. Gastrointestinal biopsy specimens showed numerous sarcoidosis nodules without neoplastic proliferation in the stomach, small intestine, and rectum. The patient's course was favorable after treatment with prednisone and chlorambucil. Disseminated gastrointestinal sarcoidosis may be a previously unidentified cause of protein-losing enteropathy.

Bone Marrow↗
PubMed1992

Low grade B cell mucosa associated lymphoid tissue lymphoma of the stomach: clinical and endoscopic features, treatment, and outcome.

A retrospective study of the clinical and endoscopic features of low grade gastric lymphomas of mucosa associated lymphoid tissue (MALT) in 16 patients together with treatment and outcome was undertaken. Immunohistochemical studies of fresh tissue easily distinguished MALT lymphoma from benign reactive lymphoid hyperplasia (pseudolymphoma) and showed that tumour cells had the characteristic phenotype indicative of their origin from MALT. Persistent epigastric pain was the main presenting complaint, and was often associated with acute bleeding, anaemia, or weight loss. Eight patients had a past history of recurrent peptic ulcers or gastritis. The endoscopic appearance suggested malignancy in only half the cases and was compatible with gastritis or a benign peptic ulcer in the remainder. There was extragastric involvement of other mucosal sites in eight patients (mainly the lung, but also the parotid gland and small bowel), but rarely was bone marrow and never the spleen or peripheral lymph nodes affected. Conservative treatment with long term cyclophosphamide was effective in both stage I and stage IV disease, and all the patients are alive after a median follow up of 4.5 years. These findings confirm that low grade gastric MALT lymphomas are usually indolent tumours with non-specific endoscopic aspects and show that dissemination to other mucosal sites was more frequent than previously reported. Monochemotherapy could be an effective alternative treatment to surgery.

Adult↗
PubMed1987

Dental pulp exposed to the CO2 laser beam.

Traumatic inflammation due to application of CO2 laser beam on teeth (dentin and pulp) of Beagle dogs and Macaca Monkeys, stimulate in dentino-pulpal tissue morphological phenomena studied after 5 days, 1, and 3 months by microscopy and microradiography. After a dentin exposure to a density of energy from 2 X 10(3) J/cm2, the first cell layers of the pulp tissue show a rarefaction and a cellular degeneration, followed by a neoformation of calcified dentin, of about 300 microns thick in 3 months, due to the excitation of odontoblasts or produced by pulpal cells functioning before. A density of energy of 10(3) J/cm2 order applied to the pulp beads to its partial necrosis, to various inflammatory aspects and to a quasi-constant regeneration by a neo-dentin bridge of 200 microns at 1 month. The analysis of cell activity seems able to be investigated from this method.

Animals↗
PubMed1985

[Experimental research on the preparation of dentin-pulp tissue of teeth exposed to CO2 laser beams in dogs and macaques (Macaca mulatta and Macaca fascicularis].

Traumatic inflammation due to application of CO2 laser radiation (lambda = 10.6 microns) on the dentin and on pulp of 342 teeth of 8 dogs (Beagle) and of 6 monkeys (Macaca sp. mulatta et fascicularis) stimulate in dentino-pulpal tissue morphological phenomenon, studied after 5 days, 1 and 3 months by microscopy and microradiography. The dentin exposed to a density of energy of: 2 X 10(3) J/cm2 shows a burn, a rarefaction and a cellular degeneration, followed by a neoformation of calcified dentin, of about 300 microns thick in 3 months, due to the excitation of odontoblasts or produced by pulpal cells functioning before. A density of energy of 10(3) J/cm2 order applied to the pulp beads to its partial necrosis, to various inflammatory aspects (vascular, cellular, tissular) and to a quasi-constant regeneration of by a neo-dentin bridge of 200 micron at 1 month. This method seems able to allow the analysis of cell activity (start, activation, blocking).

Animals↗
PubMed1985

[Reconstructive microsurgery of the vas deferens. Experimental study of suture materials].

Microsurgery is the procedure of choice for vasectomy reversal. The aim of this study was two compare two different suture materials for vasovasectomy - a nonresorbable material (nylon 10/0 with a BV 6 needle), which is widely used, and a resorbable material (polyglycolic acid, also with a BV 6 needle), which has not yet been evaluated for this use. 28 Sprague-Dawley rats were operated on under microscope. Two groups were then compared, group A with nylon (n = 14) and group B with polyglycolic acid (n = 14). In each group, 8 animals had a vas deferens section and 6 had a previous vasectomy by ligature. Ten days postoperatively, the patency rate of the anastomosis was evaluated by the presence of sperm on both sides of the suture line. The contractility was assessed by mechanical stimulation. The existence of a sperm granuloma was considered as indicative of a non functional anastomosis. Three days later a fertility test was performed, lasting three months, and the number of litters was checked. The rats were sacrificed after three months, and each vas deferens was examined histologically or by electron microscope. The macroscopic results were: 57% patent anastomoses in group A and 77% in group B. 16% patent anastomoses after ligature in group A (n = 6) and 75% in group B (n = 6). The pregnancy rate was 54% in group A and 77% in group B. After previous ligation, the corresponding figures were 20% and 83% respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

[Collagenous colitis, IgA deficiency, Basedow's disease and atrophic gastritis].

In a 37-year-old woman with chronic watery diarrhea of three years duration, the diagnostic of collagenous colitis was established by optical and ultrastructural examination of rectal and colonic biopsies. No other cause of diarrhea could be found. Moreover, this patient had also selective IgA deficiency, Grave's disease and chronic atrophic gastritis of auto-immune type. Sequential treatments with loperamide, cholestyramine and antibiotics did not modified diarrhea which improved with salazosulfapyridine and betamethasone enemas. These observations suggest that collagenous colitis might be a part of the spectrum of enteropathies associated with immunoglobulin deficiencies.

Adult↗
PubMed1984

Treatment of dental decay by CO2 laser beam: preliminary results.

Results obtained from two clinical cases, representative of 1,140 human teeth treated by CO2 laser beam during 3 years, announce a new conception of treatment of dental caries. The beam (P = 4 - 5 W, energy density of 9 to 25 kw/cm2) causes a dentin healing which becomes sterile, chemically and physically more resistant than pathological dentin. In addition, this exposure leads to an activation of the dentinogenesis supported by X-ray, confirming histo-pathological results obtained from experiments performed on animals.

Adolescent↗