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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

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

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

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

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

[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

[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

[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

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

Hepatic granulomas in Whipple's disease.

Hepatic epithelioid cell granulomas that were negative for periodic acid-Schiff stain after diastase digestion were found in a 32-yr-old man who presented with painless hepatomegaly and slight fever. The patient never complained of intestinal symptoms, which in part explains why the diagnosis of Whipple's disease was made only 3 mo later, at a time when severe neurologic manifestations had appeared. The definitive diagnosis was made on the basis of the characteristic histologic findings in biopsy material obtained from jejunum and abdominal lymph nodes at laparotomy. The patient's condition, especially neurologic manifestations, rapidly improved after antibiotic therapy. It is noteworthy that Whipple's disease is generally not included among the causes of hepatic epithelioid cell granulomas. It is suggested that its possibility should be considered in patients with hepatic granulomas without obvious etiology, even in the absence of intestinal symptoms.

Adult

[Functional, morphological and biochemical study of the jejunal mucosa in cryptogenetic colitis].

The function of the jejunum has been assessed in patients with ulcerative colitis (n = 23) and Crohn's disease of the colon (n = 20) by measurement of serum folate levels, oral folic acid and D-xylose absorption. Forty-six normal subjects served as controls. The mean serum folate level was 4.5 +/- 2.0 ng/ml in patients with the disease and 7.8 +/- 1.7 ng/ml in controls (p less than 0.001) and was similarly decreased in both ulcerative colitis and Crohn's disease patients. It was lower in patients under sulphasalazine therapy (n = 15) than in those untreated: 3.5 +/- 1.5 vs. 4.8 +/- 2.1 ng/ml (p less than 0.05). Serum folate correlated with disease activity in the latter only. The peak serum folate obtained during the oral absorption test was decreased in patients: 38.9 +/- 12.9 vs. 60.8 +/- 19.3 ng/ml in controls (p less than 0.001); this decrease was similar in ulcerative colitis and Crohn's disease, in treated and untreated patients and was independent of disease activity. Basal serum folate did not correlate with peak serum folate in any patient group. D-xylose absorption was normal in every case. Jejunal biopsies were performed in 23 patients, 13 of whom had folic acid malabsorption (13 with ulcerative colitis, 10 with Crohn's disease of the colon). The crypt height/villus height ratio was abnormal (greater than 0.6) in only 2 patients and borderline in 9 others. The fragility of enterocyte brush-borders and lysosomes, as assessed by biochemical methods, was normal in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Colitis, Ulcerative