Biomedical subjects

E Okon

Publications and source records attributed to E Okon.

At least 91 records · Page 5Linked to original sources

PubMed1991

Visceral leishmaniasis: a difficult diagnosis and unusual causative agent.

In a young man who had a prolonged fever of unknown origin, hepatosplenomegaly, and progressive pancytopenia, stained smears, blood-agar cultures of bone marrow, and serologic testing for antileishmanial antibodies were negative. Biopsies from liver and bone marrow were uninformative. Visceral leishmaniasis was diagnosed only after splenectomy, when amastigotes were finally cultured from the spleen. The parasite was shown to be an unusual leishmanial parasite, possessing a mixture of intrinsic biochemical and serologic characteristics displayed independently by Leishmania tropica and Leishmania donovani sensu lato, the latter being the usual cause of visceral leishmaniasis. After splenectomy, parasites were also demonstrated in stained bone marrow aspirate smears. Recovery was uneventful after treatment with antimony for 28 days. Visceral leishmaniasis can be a cause of fever of unknown origin and should be considered in its differential diagnosis in endemic areas.

Adult↗

PubMed1991

Acromegaly due to ectopic growth hormone-releasing hormone secretion by a bronchial carcinoid tumour. Dynamic hormonal responses to various stimuli.

Ectopic GHRH is a relatively uncommon cause of acromegaly, which should be differentiated from pituitary adenoma, in order to avoid damage to the pituitary gland from unnecessary interventions. We report here on a 66-year-old man with acromegaly due to a GHRH-secreting bronchial carcinoid tumour, who recovered completely following removal of the tumour. His hormonal status was studied before and after the operation. Basal GH, GHRH, IGF-I and PRL levels, as well as plasma GH response to glucose load and TRH administration were abnormal before the operation, and became normal thereafter. The somatostatin analogue SMS 201-995 was found to be a potent inhibitor of the ectopic GHRH and the GH secretion (greater than 500 to 42 ng/l and 15.4 micrograms/l to 0.8 microgram/l, respectively). The effect on GHRH proved to be due to direct effect of somatostatin on the tumour cells, as demonstrated in tissue culture studies. A mixed meal was found immediately to suppress GHRH levels without such an effect on GH secretion. We conclude that the neuroendocrine tests usually practised in acromegaly cannot differentiate between ectopic GHRH secretion and pituitary adenoma. High plasma GHRH levels may serve as a diagnostic test for excessive GHRH production, which is almost always ectopic. These high levels are suppressible by somatostatin and a mixed meal.

Acromegaly↗

PubMed1991

Malignant fibrous histiocytoma of the skin and the conjunctiva in xeroderma pigmentosum.

Patients with xeroderma pigmentosum (XP) experience cutaneous and ocular abnormalities, including neoplasia of epithelial and melanocytic cellular origin. Black patients with XP display more severe ocular abnormalities and neoplasia. We report the clinicopathologic findings in two black young children with XP who presented with malignant fibrous histiocytoma (one of the conjunctiva and the other one of the skin of the face). These appearances of malignant fibrous histiocytoma at an unusually early age and in rare locations are, to our knowledge, the first to be reported in XP and go along with the special characteristics of XP: frequent occurrence of tumors on exposed parts of the body at a very early age.

Child, Preschool↗

PubMed1991

Increased numbers of mast cells in pemphigus vulgaris skin lesions. A histochemical study.

We have used a histochemical technique to study mast cells (MC) in skin biopsies of 8 patients suffering from pemphigus vulgaris (PV) and from 4 control volunteers. The MC were stained for 30 min with 0.5% toluidine blue, pH 0.5, counted and then restained for 5 days under the same conditions. This staining method allows the identification of two groups of MC, one that stains promptly (30 min) and one that stains after longer incubation times (5 days). After 30 min of staining, a slight increase was found in the number of MC in PV sections, in comparison with normal controls. However, when the 30 min stained sections were reincubated under the same conditions for 5 days, a significant increase in the number of MC in PV was found in comparison with 5-day-stained normal skin sections (p less than 0.005) and in comparison with 30-min-stained PV sections (p less than 0.005). The MC were distributed throughout the dermis and were concentrated in the upper dermis near hair follicles and vessels. The possible importance of the increased numbers of MC in PV is discussed.

Adult↗

PubMed1991

Gastric mucosal damage by ethanol is mediated by substance P and prevented by ketotifen, a mast cell stabilizer.

To elucidate the possible role of substance P in the pathogenesis of acute gastric mucosal damage, rats were treated intragastrically with 1.0 mL 96% ethanol, 0.6N HCl, or 25% NaCl, with or without IP coadministration of substance P, senktide, or septide (1 mumol/L per 100 g). All three peptides were found to double the mean lesion area when compared with that induced by ethanol, whereas substance P antagonist (1 mumol/L per 100 g) prevented the expansion of damage extent. The increased damage was associated with increased gastric mucosal levels of platelet activating factor, leukotriene B4, and leukotriene C4. Substance P antagonists also reduced by half the extent of the gastric damage induced by ethanol when administered by itself. WEB 2086 (platelet-activating factor antagonist; Boehringer Ingelheim KG, Germany), hydroxyzine (H1 blocker), and cimetidine (H2 blocker) reduced lesion area by 50%, but only in rats treated with both substance P and ethanol. Ketotifen (mast-cell stabilizer) (100 micrograms/100 g), administered orally 30 minutes before damage induction, totally abolished the extent of the damage induced by either ethanol or the coadministration of ethanol and peptides in the surface epithelium of the entire mucosa. The protective effect of ketotifen was accompanied by significant reduction in mucosal generation of platelet-activating factor, leukotriene C4, and leukotriene B4. Similar mucosal protection was afforded by ketotifen against damage induced by 0.6N HCl, 25% NaCl, or indomethacin. Therefore, it is suggested that substance P is involved in the pathogenesis of acute ethanol-induced gastric mucosal damage. The effective mucosal protection provided by ketotifen indicates the important role of mast cells and their mediators in the pathogenesis of acute gastric mucosal damage and may have therapeutic implications.

Animals↗

PubMed1990

Syncytial variant of nodular sclerosing Hodgkin's disease. A new clinicopathologic entity.

The clinicopathologic and histopathologic features of an unusual morphologic variant of nodular sclerosing Hodgkin's Disease (HD) termed the syncytial variant has been reported recently. We report eight new cases with this unique morphology, identified by reviewing the histopathology of 58 patients with nodular sclerosing HD treated in our institute between 1982 and 1988. The clinicopathologic and histopathologic data of these cases are reported and we emphasize this new entity and the difficulties encountered in the morphologic diagnosis. All of the eight patients had a difficult initial clinical course, and were in a clinically advanced stage of the disease at the time of diagnosis. We cite a statistical comparison of the clinical features of the different forms of nodular sclerosing HD.

Adolescent↗

PubMed1990

Uterine leiomyosarcoma in pregnancy.

A leiomyosarcoma was found unexpectedly during a cesarean section. The tumor was a solitary pedunculated mass and there was no evidence of spread beyond the uterus. The management of this patient, because of her age, low parity and desire for having more children, was conservative. At 3 years after cesarean section there was no evidence of recurrence.

Adult↗

PubMed1990

Anti-estradiol immunoperoxidase labeling of nuclei, not cytoplasm, in paraffin sections, determines estrogen receptor status of breast cancer.

We evaluated a commercially available polyclonal antibody to 17 beta-estradiol as the basis for an estrogen receptor (ER) assay of breast carcinoma in formalin-fixed paraffin tissues and then compared it with both the ER-ICA antibody in serial paraffin sections and the biochemical assay of corresponding fresh tissue. Using the estradiol antibody, 49 of 50 cases showed some cytoplasmic staining; 38 cases had nuclear staining. Sensitivity and specificity for different proportions of positive nuclear and cytoplasmic staining were calculated using receiver-operator characteristic curves. The optimum correlation with the biochemical assay was obtained with nuclear staining alone. Greater than 30% nuclear positivity as a cut-off point yielded a sensitivity of 76% and a specificity of 82%. The corresponding ER-ICA values in 38 cases yielded a sensitivity of 93% and a specificity of 56%. The methodology for the ER-ICA assay was more technically demanding in paraffin sections than that of the estradiol antibody and considerably more expensive. This study is the first to show that with nuclear staining only, and not cytoplasmic staining, as the parameter of positivity, the immunocytochemical assay of ER with anti-17 beta-estradiol antibody in routinely processed, formalin-fixed, archival material is an accurate and specific method for the determination of the ER status of breast carcinoma.

Antibodies, Monoclonal↗

PubMed1990

The role of platelet activating factor [correction of actor] in acute gastric injury and its protection by sucralfate.

Platelet activating factor, a potent inflammatory mediator, has been reported to induce gastrointestinal damage, whereas its inhibition or antagonism is associated with mucosal protection. The aim of the present study was to elucidate the association between acute experimental gastric damage and mucosal platelet activating factor generation in the rat, and to evaluate the protective effect of sucralfate in relation to mucosal platelet activating factor formation. Gastric damage in the rat was induced by either subcutaneous injection of indomethacin 30 mg/kg or intragastric administration of aspirin 100 mg/kg, hydrochloric acid 0.6 N, taurocholate 30 mM, ethanol 96%, or sodium chloride 25%. All agents induced a significant increase in mucosal platelet activating factor levels concomitantly with induction of mucosal damage. Pretreatment with sucralfate 150 mg/rat provided a significant macroscopic and microscopic mucosal protection in all experimental models. This protection was associated with a significant decrease in mucosal platelet activating factor level in the hydrochloric acid, taurocholate, ethanol and hyperosmolar sodium chloride treated rats, whereas it remained unchanged in the aspirin and indomethacin treated rats. The data imply that platelet activating factor may have a limited role in the pathogenesis of indomethacin or aspirin induced damage, where other mechanisms such as cyclooxygenase inhibition dominate. In the damage induced by topical strong irritants, platelet activating factor may have a major pathogenetic role.

Animals↗

PubMed1990

Malignant fibrous histiocytoma of the conjunctiva.

Malignant fibrous histiocytoma (MFH) of the conjunctiva is an extremely rare tumour, and only three previous cases have been reported. We describe two patients with MFH of the conjunctiva: a 58-year-old white male with epibulbar tumour who had exenteration and is alive after five years' follow-up, and a 3 1/2-year-old African girl with xeroderma pigmentosum and an MFH of her right eye conjunctiva, the first reported case of this association. The characteristics and the methods of diagnosis of MFH are discussed.

Child, Preschool↗

PubMed1990

High incidence of cholelithiasis in older patients with homozygous beta-thalassemia.

The records of 48 patients with homozygous beta-thalassemia were reviewed for evidence of cholelithiasis by abdominal ultrasonography or plain abdominal X-ray. The presence of cholelithiasis was reported in 25 patients (52%). The incidence increased with age to 83% in patients over 31 years of age. Gallstones were more frequent among patients with beta-thalassemia intermedia and with less blood transfusion requirements. Eleven patients with cholelithiasis (44%) became symptomatic. Eight received operations on an elective or semielective basis. Another patient had incidental cholecystectomy during splenectomy. The preoperative evaluation included abdominal ultrasonography, nucleotide biliary scan and evaluation of the cardiopulmonary status. Due to the longer survival of patients with homozygous beta-thalassemia, the problem of cholelithiasis is becoming more frequent.

Adolescent↗

PubMed1990

Cardiopulmonary assessment in beta-thalassemia major.

Thalassemia patients succumb at a young age to congestive heart failure. Hitherto, attention has been focused on left ventricular function. This report emphasizes right ventricular dysfunction and abnormal pulmonary function. We performed cardiopulmonary evaluation, including echo-Doppler, spirometry, CO diffusion (DCO), and blood gas analyses in 35 patients with homozygous beta-thalassemia maintained by multiple blood transfusions. Six autopsy lung specimens were studied. Thalassemia patients exhibited pulmonary dysfunction, characterized by hypoxemia (85 percent of the patients were outside the 95 percent confidence limits), reduced lung volumes (51 percent), flow rates (63 percent) and DCO (50 percent). Right ventricular dysfunction was more prevalent than left ventricular dysfunction. Furthermore, 75 percent of the patients had evidence of pulmonary hypertension consistent with more frequent right ventricular rather than left ventricular dysfunction. Our findings suggest that in thalassemia patients, complex cardiopulmonary abnormalities precede the final outcome of congestive heart failure.

Adult↗

PubMed1990

Rectal administration of nonsteroidal antiinflammatory drugs. Effect on rat gastric ulcerogenicity and prostaglandin E2 synthesis.

Oral administration of nonsteroidal antiinflammatory drugs induces gastroduodenal mucosal damage in experimental animals as well as in humans. The aim of the present study was to evaluate the effect of rectally administered nonsteroidal antiinflammatory drugs on gastric mucosal damage, as well as on mucosal prostaglandin E2 synthesis. Fasting male rats were treated intrarectally with 0.5 ml 1% NaHCO3 solution containing several concentrations of either indomethacin, aspirin, ibuprofen, diclofenac, ketoprofen, or sulindac and concomitantly received 1 ml of 150 mM HCL intragastrically. Control rats received intrarectally the vehicle only. After 4 h, lesions in the secretory part of the stomach were scored and mucosal prostaglandin E2 synthesis was determined by the ex vivo prostaglandin generation technique. Dose-dependent mucosal damage was observed in indomethacin- and diclofenac-treated rats. Ketoprofen damage did not show dose dependency. In sulindac- and aspirin-treated rats, as well as in controls, no damage was detected. All drugs induced a significant and comparable degree of inhibition of prostaglandin E2 synthesis. There was no correlation between the severity of the mucosal damage and the inhibition of prostaglandin E2 synthesis. The ulcerogenicity of rectally administered nonsteroidal antiinflammatory drugs is therefore not directly related to the degree of inhibition of prostaglandin E2 synthesis and is probably related to the specific chemical and pharmacokinetic properties of each individual drug.

Administration, Rectal↗

PubMed1990

Gastrointestinal manifestations in Castleman's disease.

Castleman's disease is a relatively rare disorder of lymphoid tissue. The disease is considered benign in its localized form, but severe in the multicentric type. Gastrointestinal manifestations were occasionally described. We herein report four patients with histologically proved Castleman's disease in whom various and different clinical and pathological manifestations were found in the gastrointestinal tract, correlated with the primary disease. We believe that the digestive tract may be secondarily involved in Castleman's disease and, in some cases, gives the first manifestation of the disease.

Adult↗

PubMed1989

[Torsion of the appendix in a child].

Torsion of the vermiform appendix is a rare condition that simulates acute appendicitis. An 8-year-old girl with symptoms suggestive of acute appendicitis is reported. At operation the appendix was found to be twisted 72 degrees and was resected.

Acute Disease↗

PubMed1989

Endometrial glandular haemosiderosis in homozygous beta-thalassaemia.

Female patients with beta-thalassaemia major usually suffer from hypogonadotropic hypogonadism associated with amenorrhea, anovulation and infertility, attributed to the deposition of haemosiderin in the pituitary gland as well as in the ovaries. Pregnancies are rare and, with few exceptions, occur mainly in patients with beta-thalassaemia intermedia. Our study presents histopathological evidence that deposition of haemosiderin occurs in the endometrial glandular epithelium of 3 patients with beta-thalassaemia major. This deposition is mainly evident in the apical part of these cells above the nuclei, and should be taken into consideration as a contributing factor to the infertility in these patients by altering endometrial receptivity for implantation. In 2 patients who received effective iron chelating treatment with desferrioxamine the endometrial haemosiderin deposits either disappeared (patient C.R.), or were significantly reduced (patient G.L.).

Adult↗

PubMed1989

Direct demonstration of iron in a term placenta in a case of beta-thalassemia major.

Successful term pregnancy in homozygous beta-thalassemia is rare. A pregnant patient with thalassemia usually is found to have chronic anemia concurrent with tissue and circulatory iron overload. We have demonstrated and localized iron deposits in a term placenta of a patient with homozygous beta-thalassemia with the use of routine histochemical staining.

Adult↗

PubMed1989

Dysphagia in a child with aggressive fibromatosis of the esophagus.

A case of a girl who developed severe dysphagia from an aggressive fibromatosis involving the cervical esophagus is reported. A 3 x 4 cm unencapsulated fibrous tumor was completely excised with the involved esophageal wall. The esophageal defect was bridged by an inverted skin tube with good functional and cosmetic results. Eight years later the patient is disease-free. Primary radical excision is the treatment of choice of aggressive fibromatosis.

Child, Preschool↗