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Biomedical subjects

E Okon

Publications and source records attributed to E Okon.

At least 73 records · Page 4Linked to original sources
PubMed1993

Blocking lymphoma invasiveness with a monoclonal antibody directed against the beta-chain of the leukocyte adhesion molecule (CD18).

The same integrin adhesion molecules used by normal leukocytes for traffic and localization in inflammation sites may be used by malignant cells for dissemination. Identifying the adhesion molecules and then blocking them with appropriate antibody may therefore prove useful for controlling tumor spread. This prediction was tested on a spontaneous murine T cell lymphoma (LB) that expresses LFA-1 adhesion molecules. The adhesion molecules were identified by fluorocytometry and immunoprecipitation with anti-CD18 mAb (M18/2). Subcutaneously inoculated LB lymphoma rapidly infiltrated the spleen and the lymph nodes, as indicated by histologic examination and [3H]thymidine incorporation assay of proliferating LB cells derived from the invaded organs. The normal organization of the lymphoid organs was totally effaced by the infiltrating LB cells. Intravenous injection of anti-CD18 mAb, protein G-purified anti-CD18 mAb, or its F(ab')2 fragments (but not irrelevant control mAb) blocked the invasion of the s.c. inoculated lymphoma into the spleen. Whereas i.v. injected anti-CD18 mAb could not block the infiltration of LB cells into the lymph nodes, local s.c. injection of this antibody near the lymph nodes partially inhibited lymphoma invasion into these organs. It was further found that LB cells form aggregates with spleen cells but not with lymph node cells. In addition, spleen-infiltrating LB cells invade both the spleen and the lymph nodes after s.c. injection. On the other hand, lymph node-infiltrating LB cells invade mainly the lymph nodes under similar circumstances.

Animals↗
PubMed1993

Role of vasoactive intestinal peptide (VIP) in pathogenesis of ethanol-induced gastric mucosal damage in rats.

To elucidate the possible role of vasoactive intestinal peptide (VIP) in the pathogenesis of acute gastric mucosal damage, rats were treated intragastrically with 1.0 ml 96% ethanol with or without intravenous or intraperitoneal coadministration of VIP (1 nmol/liter to 1 mumol/liter/100 g). VIP was found to double the mean lesion area when compared with that induced by ethanol alone (P < 0.05), an effect that was prevented by VIP antagonist (1 mumol/liter/100 g). A substance P antagonist (1 mumol/liter/100 g) also reduced the extent of gastric damage induced by coadministration of VIP and ethanol. VIP antagonist or substance P antagonist significantly reduced ethanol-induced gastric mucosal damage. Gastric mucosal levels of LTB4, LTC4, VIP, and substance P were significantly increased in ethanol-treated rats as compared with saline-treated animals (P < 0.05). The augmentation of ethanol-induced damage by VIP was associated with increased gastric mucosal levels of LTB4. In VIP-treated rats, gastric mucosal levels of substance P were found to be significantly increased compared with control rats (P < 0.05). Administration of VIP to pyloric-ligated rats significantly increased gastric acid output and blood pepsinogen A levels as compared with saline treated rats (P < 0.05). Ketotifen, a mast cell stabilizer (100 micrograms/100 g), administered orally 30 min before damage induction by ethanol, with or without VIP, totally abolished the damage of the surface epithelium of the entire gastric mucosa and significantly reduced the mucosal levels of LTC4 and LTB4 (P < 0.05). It is suggested that VIP is involved in the pathogenesis of acute ethanol-induced gastric mucosal damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1993

A kindred with Griscelli disease: spectrum of neurological involvement.

We report four members of a highly consanguineous family with silver-grey pigmentation of hair, two of whom had skin histology compatible with Griscelli disease. Unlike previously reported patients, they did not suffer from recurrent infections. In addition, there was a spectrum of neurological involvement varying from mild cognitive delay with a convulsive disorder in one patient, to a fatal degenerative course in three others. One patient developed a prolonged febrile illness with histological evidence of florid lymphoid hyperplasia.

Child, Preschool↗
PubMed1993

Octreotide effectively decreases mucosal damage in experimental colitis.

The effect of octreotide, a synthetic analogue of somatostatin, on the modulation of the acetic acid model of experimental colitis was examined. Colitis was induced by intracolonic administration of 2 ml of 5% acetic acid. The inflammatory response elicited by the acetic acid resulted in increased colonic synthesis of platelet activating factor, leukotriene B4 and decreased mucosal somatostatin levels. Subcutaneous administration of octreotide (10 micrograms/rat) 1 hour before or immediately after damage induction, as well as 1 and 23 hours after acetic acid application, resulted in a significant reduction in mucosal damage. The protective effect was accompanied by a significant reduction in platelet activating factor activity, leukotriene B4, and vasoactive intestinal peptide concentrations. There were no significant changes in mucosal leukotriene C4 and calcitonin gene related peptide levels. This study shows that acetic acid induced colitis is pharmacologically manipulated by octreotide. The mechanism of action of octreotide has not yet been fully determined. The potential use of octreotide in treating active inflammatory bowel disease remains to be evaluated.

Acetates↗
PubMed1993

A monomorphic adenoma of the minor salivary glands presenting at the base of the tongue: a case report and review of the literature.

A case of a monomorphic adenoma of the minor salivary glands situated at the base of the tongue in a 49-year-old female is reported. The patient had a prolonged clinical course of eight years' duration. The histopathologic, immunohistologic and ultra-structural findings are described. A review of the literature concerning minor salivary gland tumors and their location in the oral cavity is presented. This is the first case, to our knowledge, of a monomorphic adenoma presenting at the base of the tongue. The difficulties in its diagnosis are discussed specifically in regard to its location.

Adenoma↗
PubMed1992

Acanthocephalan infection in man in northern Nigeria.

Acanthocephalan ova, indistinguishable from the ovoid eggs of Moniliformis moniliformis, were detected in the stools of a 45-year-old man at the University of Jos Health Clinic, Nigeria. The patient complained of general body weakness, occasional giddiness and intermittent burning sensations around the umbilicus. Successful treatment with niclosamide and the possible source of infection are communicated.

Animals↗
PubMed1992

Aspergillus quadrilineatus, a new causative agent of fungal sinusitis.

Aspergillus quadrilineatus was found to be the etiologic agent of pansinusitis in a patient suffering from acute nonlymphoblastic leukemia and who had undergone allogeneic bone marrow transplantation. A. quadrilineatus was cultured from biopsy specimens of the maxillary sinus, and tissue sections with fungal stains showed a necrotic area containing dichotomously branching septate hyphae, which is morphologically consistent with Aspergillus species. The patient was successfully treated with a combination of surgical debridement, granulocyte transfusions, and intravenous administration of amphotericin B-cholesterol sulfate colloidal dispersion. This is the first report of an infection caused by A. quadrilineatus.

Adult↗
PubMed1992

Ketotifen effectively prevents mucosal damage in experimental colitis.

The effects of ketotifen, a 'mast cell stabiliser,' on two models of experimental colitis were examined. The inflammatory response elicited by either trinitrobenzene sulphonic acid or acetic acid resulted in increased colonic synthesis of platelet activating factor, prostaglandin E2, thromboxane B2, leukotrienes B4 and C4, and myeloperoxidase activity. Intragastric administration of ketotifen 100 micrograms/100 grams twice daily significantly decreased mucosal damage when given prophylactically 48 hours before the induction of colitis and then throughout the experiment. This effect was consistent in both models and was accompanied by a significant reduction in mucosal generation of platelet activating factor, prostaglandin E2, thromboxane B2, and leukotrienes C4 and B4. Myeloperoxidase activity was reduced as well, reaching significance only in the acetic acid model. This study shows that both trinitrobenzene sulphonic acid and acetic acid colitis can be pharmacologically manipulated by ketotifen. The mechanism of action of ketotifen has not yet been determined. Ketotifen's potential in the treatment of active inflammatory bowel disease or in the prevention of exacertations, or both, remains to be elucidated.

Acetates↗
PubMed1992

Effect of drugs on colonic eicosanoid accumulation in active ulcerative colitis.

The effect of immunosuppressive drugs, 4-aminosalicylic acid (4-ASA), acetyl 5-aminosalicylic acid (5-ASA), and ketotifen on human colonic eicosanoid accumulation was evaluated in view of enhanced accumulation in patients with active ulcerative colitis. Azathioprine (100 micrograms/ml), cyclosporin (100 micrograms/ml), and methotrexate (100 micrograms/ml) significantly inhibited, by 25-35%, prostaglandin E2 (PGE2) accumulation by organ-cultured colonic mucosa of ulcerative colitis patients. Methotrexate was the only immunosuppressive drug that inhibited leukotriene B4 (LTB4) accumulation (50%), whereas azathioprine inhibited the accumulation of leukotriene C4 (LTC4) (25%). 5-ASA and its metabolite, acetyl 5-ASA, inhibited by 20-70% PGE2, LTB4, and LTC4 accumulation in the culture, supporting the contention that acetyl 5-ASA is as active as 5-ASA in these respects. 4-ASA had no effect on any of the eicosanoids. Ketotifen, a mast cell stabilizer, significantly inhibited the accumulation of PGE2, LTB4, and LTC4 by 33-60%. These results suggest a potential, new, unrecognized mode by which the immunomodulators induce part of their therapeutic effects in inflammatory bowel disease and support the contention that acetyl 5-ASA is as active as 5-ASA. The results obtained also indicate that ketotifen, used effectively in the prevention of bronchial asthma, inhibits the accumulation of colonic eicosanoids and, thus, may be of value in the treatment of inflammatory bowel disease.

Adult↗
PubMed1992

Obstructive solitary bronchial non-Hodgkin's lymphoma--a rare presentation of primary extranodal disease.

Endobronchial involvement by non-Hodgkin's lymphoma (NHL) is uncommon and usually occurs in the presence of more generalised disease. Solitary endobronchial lymphoma in the absence of disease elsewhere is extremely rare. In this report we describe a patient with an obstructing endobronchial mass which was the initial manifestation of NHL. The patient was treated initially with radiotherapy followed by cyclic combination chemotherapy with initial complete resolution of the endobronchial disease. However, he subsequently developed widespread lymphoma. This unusual presentation of NHL is discussed and the relevant literature is reviewed.

Aged↗
PubMed1992

Pulmonary involvement as the major manifestation of chronic lymphocytic leukemia.

Respiratory symptoms and abnormal findings on chest X-ray are frequently noted in patients with chronic lymphocytic leukemia (CLL). However, most of these represent pulmonary infections or mediastinal lymphadenopathy, and leukemic involvement of the lung is seldom diagnosed during life. In this report we describe three patients with non-progressive, responsive CLL who developed biopsy proven pulmonary infiltration with CLL. In one case, pulmonary involvement was the sole manifestation of recurrent disease and a second case had little disease elsewhere with minimal CLL in the blood at the time pulmonary involvement appeared. In all three cases, transbronchial biopsy and bronchoalveolar lavage performed during fibreoptic bronchoscopy provided adequate tissue for diagnosis. We conclude that CLL may involve the lung even in the presence of a low peripheral white blood cell count with responsive disease elsewhere, and can readily be diagnosed by transbronchial biopsy and bronchoalveolar lavage.

Adult↗
PubMed1992

Growth rate analysis of lung metastases appearing 18 years after resection of cutaneous adenoid cystic carcinoma. Case report and review of the literature.

Growth rate analysis of lung metastases of a cutaneous adenoid cystic carcinoma, which appeared 18 years after the resection of the primary tumor from the scalp is presented. The doubling times of the metastases were long compared with that of other lung metastases. They were 22 months for the metastasis in the right lung and 70 months for the metastasis in the left lung, with a shortening of the doubling time in the left side to 10.4 months in the last 4 months of observation. Backward extrapolation showed that the metastases to the lung were disseminated before the diagnosis and surgical resection of the primary tumor. To our knowledge, this is the third reported case of lung metastases from a cutaneous adenoid cystic carcinoma out of 25 documented cases. We present a review of the literature and discuss the clinical implications of our findings.

Adult↗
PubMed1992

Successful T cell-depleted allogeneic bone marrow transplantation in a child with recurrent multiple extramedullary plasmacytomas.

Multiple plasmacytomas with IgA paraproteinemia, a low grade lymphoid neoplasm of differentiated B cells rarely seen in the young, were encountered in a 10-year-old child. T cell-depleted allogeneic bone marrow transplantation (BMT) was performed because of progressive disease despite chemotherapy. Donor T cells were infused after transplantation in gradually increasing numbers to achieve a graft-versus-tumor effect. Complete eradication of all tumor masses was achieved following BMT with normalization of serum immunoglobulin levels. The patient remains in complete remission 4 years after BMT. Allogeneic BMT should be considered early in the course of low-grade lymphoid malignancy in the younger age group.

Bone Marrow Transplantation↗
PubMed1992

Nodular vasculitis associated with propylthiouracil therapy.

Cutaneous vasculitis is a rare complication of propylthiouracil therapy. We describe a patient who presented with lower extremity subcutaneous nodules, hemorrhagic bullae, and necrotic ulcers during treatment with this agent. Examination of a skin biopsy specimen revealed nodular vasculitis. This type of vasculitis has not been described in association with propylthiouracil therapy before. Nodular vasculitis not associated with the drug is characterized by a chronic protracted course, whereas in the patient reported the lesions rapidly regressed when use of the drug was discontinued.

Aged↗