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Biomedical subjects

F Ben Ayed

Publications and source records attributed to F Ben Ayed.

At least 37 records · Page 2Linked to original sources
PubMed1993

Emergence of non-major-histocompatibility-complex-restricted lytic CD8+ cells in the blood of nasopharyngeal carcinoma patients.

A large body of evidence has suggested that the Epstein-Barr virus (EBV) is strongly associated with undifferentiated nasopharyngeal carcinoma. Immunologically, this neoplasia is characterized by the absence of anti-EBV circulating cytotoxic T lymphocytes (CTL), despite a high number of peripheral activated CD8+ cells, as previously determined in our laboratory. In order to determine whether the absence of anti-EBV CTL is related to a reduced number of circulating anti-EBV effector cells, we attempted to expand these hypothetical specific T cells by induction of proliferation with recombinant interleukin-2 (rIL-2), in the, absence of any stimulator cells. Optimal conditions for stimulation of peripheral blood lymphocytes (PBL) of nasopharyngeal patients were obtained with 100 U/ml rIL-2 during 10 days of culture. PBL treated with rIL-2 induced a selective expansion of CD8+ cells and generated a potent cytotoxicity towards autologous or HLA-compatible lymphoblastoid cell lines, used as target cells in a chromium-release thest. However, this cytolysis was non-MHC-restricted, since, the monoclonal antibodies anti-(HLA class I) and anti-(HLA class II) were inefficient in inhibiting this cytotoxicity. Interestingly, purified CD8+ cells acquired the capacity for non-MHC-restricted cytolysis.

CD8 Antigens↗
PubMed1992

Alpha heavy chain disease alpha mRNA contain nucleotide sequences of unknown origins.

Human alpha heavy chain disease is characterized by the production of abnormally short alpha IgH chains. In previously published cases it has been found that the malignant cells produce abnormal alpha mRNA, lacking VH and CH1 sequences and composed of a leader sequence peptide, sequences of variable length (69 to 84 bp) and of unknown origin, followed by normal CH2 and CH3 sequences. In this study we established the nucleotide sequence of alpha mRNA for six cases of alpha heavy chain disease. We observed that all six alpha mRNA lack the VH and CH1 sequences as do those previously described. They also contain in-frame inserts of unknown origin between the leader peptide and the normal CH2 and CH3 coding sequences. These inserts are of variable length (42 to 105 bp) and they are unrelated. These results suggest the existence of a common mechanism defect leading to deletions/insertions in alpha heavy chain disease rather than a specific interaction between alpha 1 IgH gene with a unique defined molecular species.

Amino Acid Sequence↗
PubMed1991

[Malt digestive system lymphomas and alpha heavy chain diseases. Histological and immunohistochemical study. Apropos of 3 cases].

Malt lymphomas are lymphomas developed from mucosa associated lymphoid tissue and may involve many sites such as the gastrointestinal tract, salivary glands, thyroid gland lung, breast and female genital tract. Histologically, their diagnosis is based upon the existence of four elements: centrocyte-like cells that are responsible for lymphoepithelial lesions that are sometimes very difficult to demonstrate reactive or residual follicles and plasma cells. We study 2 cases of gastric Malt lymphoma and one of alpha heavy chain disease involving the small intestine and the stomach and we try to define the common features of Malt lymphoma, alpha chain disease and non-secretary IPSID, which all present the clinical tetralogy mentioned above.

Adult↗
PubMed1991

[Pleural talc treatment using thoracoscopy in lymphomatous pleurisy].

The authors report their experience of pleural talcage under thoracoscopy in 21 cases of lymphomatous pleurisy. This represents 9.6% of the total number of cancerous pleurisies treated with talc over four years. A successful result with talcage was achieved in 84% of cases. The success of failure of talcalge seems to depend on the macroscopic appearance (the existence of masses or nodules) as well as an abundance of pleural liquid, all constitute unfavourable factors. On the other hand the lymphoma (Hodgkins or non Hodgkins) does not seem to have any unfavourable effect.

Adult↗
PubMed1989

[Results of talc administration using thoracoscopy in neoplastic pleurisies. Apropos of 218 cases].

The authors report the results of their experience using tale pleurodesis under thoracoscopic control in the treatment of 218 cases of malignant pleural involvement. Although this technique is well tolerated it is necessary to note certain factors which prevent a successful pleurodesis (12% of cases). Thus, huge effusions greater than 12 litres, pleural involvement with large tumour masses, a very long history and patients aged more than 70 years were all factors contributing to a poor outcome. The success of pleural talc also depends on the nature of the primary cancer, for example in our series broncho-pulmonary cancers yielded better results than those effusions which were secondary to ovarian cancers.

Adult↗
PubMed1988

[Malignant lymphoma on a gastric stump].

We report a case of lymphoplasmocytic and immunoblastic gastric remnant lymphoma occurring in a 51 year-old male. This patient had undergone subtotal gastrectomy for a gastric peptic ulcer at age 37. Histologic findings in the initial gastric specimen showed a dense lymphoid infiltrate surrounding the ulcer within the gastric mucosa. This proliferation was grouped into distinct follicles, and was compatible with pseudo-lymphoma. The progression of pseudo-lymphoma to malignant lymphoma is suggested.

Adult↗
PubMed1987

[Cancer of the cervix uteri in Tunisia. Clinical presentation and development over a 10-year period].

Carcinoma of the cervix is still common in Tunisia, where it occupies second place among malignant diseases in women. Accounting for 17% of the female population of the National Cancer Institute of Tunis, it is preceded only by breast cancer (27%). Study of the factors concurrent with the origin of carcinoma of the uterine cervix seems to indicate that its decrease is secondary to the lowered average age at marriage, to the fall in the reproduction rate among the population at large, and to improved socio-economic conditions among the poorer classes. Study of clinical features observed during two separate periods of 10 years shows a modification in the physiognomy of this cancer, with, notably, a larger frequence of lower stages (45% of stage II in 1984 vs 20% in 1974) and a slight tendancy towards the discovery of smaller non - or early - infiltrating tumors (4% in 1984 vs 0% in 1974). Efforts must continue to be made in the domaine of early detection, especially among the "high risk" population.

Age Factors↗
PubMed1985

[Diagnostic and therapeutic thoracoscopy in 83 cases of chronic pleurisy].

From May 1983 to June 1985 the authors performed a thoracoscopy as a diagnostic and therapeutic objective in 83 patients with chronic recurrent pleurisy; amongst these patients, 69 had know intra or extra thoracic cancer and the other 14 presented with an isolated pleurisy. Eight other patients had pleural carcinomatosis proven by needle biopsy and had pleural talc introduced by thoracoscopy. The examination was performed under local anaesthesia with neuroleptanalgesia; a rigid 7 mm diameter thoracoscope was used; the biopsies were performed uniquely on the parietal pleura using tropical forceps. The outcome was uncomplicated with no deaths nor any serious complications due to the method. The sensitivity of the pleural biopsy was 91.5% or 76 positive biopsies out of 83. 73 biopsies were metastatic and 3 were tuberculous pleurisies. The macroscopic appearance was strongly suggestive of malignancy in 78 patients and appeared inflammatory in 13, of whom 9 cases were positive on biopsy. The authors performed a pleural talcage in every case; a lasting pleural adhesion was obtained in 66 patients but regrettably there were 14 failures, the effusion recurring after removal of the drain. The authors stress the reduced number of incidents of pleural effusion, which confirms the good tolerance of pleural endoscopy.

Adult↗
PubMed1985

[Primary, exclusively gastric localization of alpha-chain disease: anatomo-clinical and immunohistochemical study].

We report the first case of heavy alpha-chain disease exclusively located in the stomach and in the perigastric nodes in a thirty year old Tunisian patient. Both the small bowel and the mesenteric nodes were evaluated histologically and immunochemically and were found to be free of disease. Complete remission was obtained using chemotherapy. The reasons for which the small intestinal mucosa and the mesenteric nodes, nearly constantly involved, in alpha-chain disease were spared in our case, are discussed.

Adult↗