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Biomedical subjects

E Okon

Publications and source records attributed to E Okon.

At least 19 recordsLinked to original sources
PubMed2005

Pituitary and bilateral adrenal enlargement: an unusual presentation of hepatocellular carcinoma.

Pituitary metastases account for about 1% of operated pituitary lesions. Most derive from primaries in the breast or lung. Pituitary metastases from hepatocellular carcinoma (HCC) have rarely been reported. We describe a patient in whom headache and left external ophthalmoplegia were the only presenting signs of a clinically silent and radiographically undetectable HCC, that had metastasized to the pituitary and both adrenal glands. Pituitary histology and adrenal needle biopsy failed to establish the final diagnosis, which was reached only after surgical exploration of the abdomen. This case illustrates the difficulties encountered in the histopathological diagnosis of pituitary metastasis and the need for good clinical judgment when confronting pituitary tumors with atypical features.

Adrenal Gland Neoplasms↗
PubMed2002

Expression of basic fibroblast growth factor is associated with poor outcome in non-Hodgkin's lymphoma.

It is now clear that angiogenesis and angiogenesis factors are important in the pathogenesis of haematological malignancies. High pretreatment levels of serum basic fibroblast growth factor have been shown to be associated with poor prognosis in patients with non-Hodgkin's lymphoma. The aim of this study was to evaluate whether non-Hodgkin's lymphoma cells express basic fibroblast growth factor and/or its receptor (fibroblast growth factor receptor-1) and whether basic fibroblast growth factor expression correlates with basic fibroblast growth factor serum levels, intratumoral microvessel density, and patient outcome. We measured basic fibroblast growth factor by enzyme-linked immunosorbent assay in sera taken from 58 patients with non-Hodgkin's lymphoma before treatment and in 19 of them also after treatment. Pathological specimens at diagnosis were evaluated by immunohistochemistry staining using polyoclonal antibody against factor-VIII-related antigen, basic fibroblast growth factor and fibroblast growth factor receptor-1 to determine the expression of the microvessel count and basic fibroblast growth factor and fibroblast growth factor receptor-1. The lymphoma specimens demonstrated positive staining for basic fibroblast growth factor (in 23%) and fibroblast growth factor receptor-1 (in 58.5%). The patients who expressed basic fibroblast growth factor had a significantly worse progression-free and overall survival than those who did not (P=0.003 and P=0.03 respectively), while patients expressing fibroblast growth factor receptor-1 were less likely to achieve complete remission than those lacking the receptor (33% vs 65%, P=0.047). There was no correlation of basic fibroblast growth factor staining with either serum basic fibroblast growth factor levels or microvessel count. Basic fibroblast growth factor serum levels did not change significantly after treatment These results suggest that non-Hodgkin's lymphoma specimens express basic fibroblast growth factor and its receptor (fibroblast growth factor receptor-1) and this expression is associated with poor patient outcome.

Adult↗
PubMed2001

Phenotypic expression of tissue mosaicism in a 45,X/46,X,dicY(q11.2) female.

We describe a girl who presented at the age of 11 years with short stature. She had female external genitalia and some clinical features of Turner syndrome. At laparotomy a uterus and Fallopian tubes and small gonad-like tissue masses in the region of the Fallopian fimbria were found. The tissue masses were removed and histological examination revealed no organized testicular or ovarian morphology. Remnants of Fallopian tubes, epididymis, and clusters of Leydig cells were seen but no Sertoli cells were found. Endocrine studies showed levels of sex hormones consistent with primary gonadal failure. G-banding analysis of 16 blood lymphocytes revealed the karyotype 46,X,dicY(q11.2) in all cells. Varying proportions of X and Y centromeres in blood lymphocytes, skin fibroblasts, and in the incompletely formed Wolffian and Müllerian duct derivatives were demonstrated by FISH. Molecular studies confirmed the absence of most of the long arm of the Y chromosome and an intact short arm. The SRY gene was shown to be present, but we presume that due to the mosaicism the dose was insufficient to allow normal testicular development.

Child↗
PubMed2001

Morphological study of fully and partially isolated early human follicles.

OBJECTIVE: To compare the development of fully and partially isolated human follicles by using various culture systems. DESIGN: Human ovarian material was incubated with collagenase and deoxyribonuclease. Fully and partially isolated follicles (30-50 microm) were dissected and studied under light and electron microscopy. The follicles were then cultured on and within various matrices. Fully isolated follicles were also cocultured with stromal cells. SETTING: Rabin Medical Center, a major care and referral center. PATIENT(S): Women undergoing laparoscopy. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Microscopy studies, follicular measurements. RESULT(S): Electron microscopy studies revealed an excess of lipid droplets in the granulosa cells of freshly isolated follicles. An increase in follicular size and granulosa cell number was observed only in the fully isolated follicles cultured within collagen gels for 24 hours. Most of the partially isolated follicles detached from the collagen gels. When cultured on collagen, extracellular matrix, and poly-L-lysine, both the fully and the partially isolated follicles deteriorated within the first 24 hours; coculture with stromal cells had no beneficial effect. CONCLUSION(S): The excess in lipid droplets in granulosa cells of isolated follicles might suggest that the isolation process does not yield completely healthy follicles. However, despite this finding, our studies show that fully isolated follicles, but not partially isolated follicles, can grow within, but not on, a culture matrix.

Adolescent↗
PubMed2001

Gastric corpus mucin expression after partial gastrectomy, in relation to colonization with Helicobacter pylori.

Twelve different genes for mucin have been described. MUC5AC and MUC6 encode the secreted apomucins of the stomach. A gradient from the surface epithelium (foveola) to the glands is typical for MUC5AC synthesis, whereas a gradient in the opposite direction was found for MUC6. Our goal was to determine the distribution of MUC5AC and MUC6 in the postoperative stomach, with relation to the H. pylori status. Gastric corpus biopsy specimens from patients who underwent partial gastrectomy were examined by immunohistochemistry for mucin gene (MUC5AC and MUC6) apoproteins. We used polyclonal antibodies for amino acid tandem repeats of both proteins. A scoring system (0-3) was used to assess staining intensity at four sites: the lumen, the foveola, the mucous neck cells, and the glands. Helicobacter pylori status was determined by histology and rapid urease test and was considered positive or negative when both tests were positive or negative, respectively. We studied 19 H. pylori-positive and 32 H. pylori-negative patients. No significant change in MUC5AC or MUC6 synthesis and secretion was demonstrated between H. pylori-positive or -negative patients. A gradient similar to that shown for the intact stomach (from the surface epithelium to the glands) for MUC5AC protein and an increase of MUC6 protein presentation from the mucous neck cell to the glands were demonstrated. The pattern of MUC5AC protein synthesis was not different between H. pylori-positive and -negative patients in the postoperative stomach. MUC6 expression was higher in the foveola in H. pylori-positive patients, whereas there was no difference in the other cell layers.

Gastrectomy↗
PubMed2001

Does Helicobacter pylori affect gastric mucin expression? Relationship between gastric antral mucin expression and H. pylori colonization.

BACKGROUND/OBJECTIVE: Helicobacter pylori colonizes the gastric mucous gel layer, the surface epithelium and glands. It has been shown that H. pylori infection causes aberrant expression of gastric mucins MUC 5 and MUC 6. This study aimed to determine the distribution of MUC 5 and MUC 6 in the gastric antrum of dyspeptic patients, and to investigate changes in this pattern in the presence of H. pylori and after successful eradication. MATERIALS AND METHODS: Gastric antrum biopsy specimens were examined by immunohistochemistry for mucin gene (MUC 5 and MUC 6) expression. Polyclonal antibodies were used to detect amino acid tandem repeats of each protein. A scoring system (0-3) was used to assess staining intensity at three sites: foveola, mucous neck cells and glands. H. pylori status was determined by histology and rapid urease test, and considered positive or negative when both tests were positive or negative, respectively. The study included 49 patients positive for H. pylori, in 36 of whom successful eradication was performed, and 11 H. pylori-negative patients. RESULTS: There was a gradient of MUC 5 expression, higher to lower, from the surface to the glands, which was more pronounced before eradication. Increased MUC 5 synthesis in the mucous neck cells and in the glands was found after H. pylori eradication (P = 0.016). MUC 6 was synthesized in the glands more than in the mucous neck cells or foveola. MUC 6 was also secreted into the lumen and probably comprised the superficial part of the unstirred mucous layer. CONCLUSION: The change in MUC 5 synthesis may reflect H. pylori colonization.

Adult↗
PubMed2001

[Malignant humoral hypercalcemia associated with angiotropic large B cell lymphoma].

Angiotropic large B cell lymphoma (angiotropic LCL) or intravascular large cell lymphoma (IVLCL) was diagnosed by liver and bone marrow biopsies and immunohistochemical studies in a 52 year old Caucasian male. IVLCL is a very rare disease characterized by widespread intravascular proliferation of lymphoma cells. Although it most commonly affects the central nervous system or skin and occasionally bone marrow, angiotropic LCL may be present without evidence of localized disease, as seen initially in our patient. To date, only a few cases of intravascular malignant lymphomatosis associated with parathyroid hormone related protein (PTH-rP) induced humoral hypercalcemia have been published. Our extraordinary case was diagnosed mainly by liver biopsy. The neoplastic lymphoid cells stained diffusely and strongly positive with CD-20 (Pan B) and were negative for CD-3 (Pan T) immunostain. The most significant, initial clinical finding was severe, unexplained hypercalcemia (until 18.6 mg/dl). Plasma PTH-rP showed a ten-fold increase at 8 pmol/L (normal value less than 0.8 pmol/L). Very unusual cytogenic abnormalities were found. The patient received the massive third generation combination chemotherapy comprising of Methotrexate, Doxorubicine, Cyclophosphamide, Vincristine, Prednisone and Bleomycin and developed, complete although temporary, clinical, humoral and cytogenetic remission.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Induction of resistance to diabetes in non-obese diabetic mice by targeting CD44 with a specific monoclonal antibody.

Inflammatory destruction of insulin-producing beta cells in the pancreatic islets is the hallmark of insulin-dependent diabetes mellitus, a spontaneous autoimmune disease of non-obese diabetic mice resembling human juvenile (type I) diabetes. Histochemical analysis of diabetic pancreata revealed that mononuclear cells infiltrating the islets and causing autoimmune insulitis, as well as local islet cells, express the CD44 receptor; hyaluronic acid, the principal ligand of CD44, is detected in the islet periphery and islet endothelium. Injection of anti-CD44 mAb 1 hr before cell transfer of diabetogenic splenocytes and subsequently on alternate days for 4 weeks induced considerable resistance to diabetes in recipient mice, reflected by reduced insulitis. Contact sensitivity to oxazolone was not influenced by this treatment. A similar antidiabetic effect was observed even when the anti-CD44 mAb administration was initiated at the time of disease onset: i.e., 4-7 weeks after cell transfer. Administration of the enzyme hyaluronidase also induced appreciable resistance to insulin-dependent diabetes mellitus, suggesting that the CD44-hyaluronic acid interaction is involved in the development of the disease. These findings demonstrate that CD44-positive inflammatory cells may be a potential therapeutic target in insulin-dependent diabetes.

Animals↗
PubMed2000

Microvessel density in chemosensitive and chemoresistant diffuse large B-cell lymphomas.

Preliminary reports involving a number of different kinds of tumors have indicated that microvessel quantification may be useful in predicting disease outcome. The aim of this study was to examine the relationship between microvessel density (MVD) as a parameter of tumor angiogenesis and the response to chemotherapy in diffuse large B-cell (DLBC) lymphomas. A total of 36 DLBC lymphoma patients were evaluated, 23 of them with a chemosensitive; responsive disease (median survival 8y) and 13 with a chemoresistant, refractory disease (median survival 8 months). Microvessel quantification was performed by immunohistochemical staining, using monoclonal antibodies against factor VIII related antigen (F8RA) and against platelet/endothelial cell adhesion molecule-CD31. We found that F8RA stained a significantly higher number of blood vessels (about 2.5 times more) than CD-31; 7 samples were not stained with CD-31 but were positive for F8RA. There was no significant difference between the density of microvessel staining of the two groups. In the chemosensitive DLBC lymphomas positive for F8RA, the mean number of microvessels stained was 54.5 +/- 36.1 per microscopic field (200x) examined (range 6-149) whereas in the chemoresistant group the corresponding mean number was 43.1 +/- 25.5 (range 11-94). F8RA appears to be more sensitive for staining DLBC lymphomas microvessels than CD-31. Our data demonstrate that there is no correlation between tumor MVD and response to chemotherapy in patients with DLBC lymphomas.

Adult↗
PubMed2000

Pernicious anemia, gastric carcinoid, and autoimmune thrombocytopenia in a young woman.

The association between gastric carcinoid tumors and pernicious anemia is well recognized. Such tumors occur in the presence of achlorhydria, chronic atrophic gastritis, hypergastrinemia, and enterochromaffin-like cell hyperplasia. In this case report, a 29-year-old woman with pernicious anemia and autoimmune thrombocytopenia who developed gastric carcinoid tumors of the gastric body is described. This is the second description of pernicious anemia associated with autoimmune thrombocytopenia. This association in a young woman together with the therapeutic options and decisions that were taken in the treatment of the patient are discussed.

Adult↗
PubMed2000

HLA-DR and beta 2 microglobulin expression in medullary and atypical medullary carcinoma of the breast: histopathologically similar but biologically distinct entities.

AIMS: To examine the expression of HLA-DR and beta 2 microglobulin in medullary carcinoma and atypical medullary carcinoma of the breast to determine if the effective presentation of tumour antigens to the immune system can differentiate between these two histopathologically similar entities. METHODS: Expression of HLA-DR and beta 2 microglobulin was examined by immunohistochemical methods in five samples of medullary carcinoma of the breast, which has a relatively favourable prognosis, six samples of atypical medullary carcinoma of the breast, which has a prognosis closer to that of regular invasive duct carcinoma, and 20 samples of invasive duct carcinomas, 10 with an accompanying lymphocytic infiltrate. RESULTS: A positive and significant correlation was found between tumour type and both HLA-DR and beta 2 microglobulin expression. Expression was most prominent in medullary carcinoma, followed by atypical medullary carcinoma and invasive duct carcinoma with and without lymphocytic infiltrates. The mean intensity and percentage of HLA-DR tumour immunostaining were significantly higher in medullary carcinoma than in the other three tumour groups, as was the mean intensity of beta 2 microglobulin immunostaining. Mean percentage of beta 2 microglobulin immunostaining was significantly higher in medullary carcinoma than in invasive duct carcinoma without lymphocytic infiltrates, and showed a trend to increase from invasive duct carcinoma with lymphocytic infiltrates to atypical medullary carcinoma and medullary carcinoma. CONCLUSIONS: Medullary carcinoma and atypical medullary carcinoma of the breast differ in their expression of HLA-DR and beta 2 microglobulin. The relatively favourable prognosis of medullary carcinoma of the breast may be related to effective tumour antigen presentation to the immune system through MHC-I and MHC-II expression. Immunotherapy aimed at MHC-I and MHC-II induction might have a beneficial effect in breast cancer.

Adult↗
PubMed1999

The gonadotropin-releasing hormone family of neuropeptides in the brain of human, bovine and rat: identification of a third isoform.

The mammalian gonadotropin-releasing hormone (GnRH-I), which regulates reproduction, was the first isoform of GnRH that was identified in mammals. Recently, we and others have demonstrated the existence of a second isoform of GnRH in the brain of mammals. The presence of a third isoform of GnRH, GnRH-III, in the brain of mammals is reported herein. GnRH-III, extracted from the brain of bovine and human, was purified by high performance liquid chromatography, using two distinct elution programs. In both, GnRH-III was eluted at the same positions as synthetic salmon GnRH, as demonstrated by radioimmunoassay. The luteinizing hormone-releasing activity of purified GnRH-III, using dispersed rat pituitary cells, was found to be similar to that of synthetic salmon GnRH. The total amount of GnRH-III, determined by radioimmunoassay, in the hypothalamus and midbrain of humans and calves is similar to that of GnRH-I. Immunohistochemical studies demonstrated GnRH-III-containing neurons in the hypothalamus and midbrain of human and GnRH-III fibers in the median eminence of rats. The distribution of GnRH-III in the brain suggests that in addition to a putative function as a neurohormone at the hypothalamic-pituitary axis, GnRH-III may have other functions. Our present results suggest that multiple isoforms of GnRH are present in the brain of mammals, and further studies are required in order to elucidate their biological functions.

Amino Acid Sequence↗
PubMed1999

Expression of the apoptosis-related oncogenes bcl-2, bax, and p53 in Merkel cell carcinoma: can they predict treatment response and clinical outcome?

Chemotherapy and radiation therapy act predominantly through the induction of apoptosis in malignancies. Merkel cell carcinoma, an aggressive malignancy with prominent apoptosis, has proved to be sensitive to both modes to a certain degree. We used immunohistochemical methods to examine 25 Merkel cell carcinomas and 8 of their lymph node metastases to assess the status of the antiapoptotic gene bcl-2 and 2 proapoptotic genes, wild-type p53 and bax. All tumors showed prominent bax immunopositivity; 76% were positive for bcl-2, and only 28% were positive for p53, the latter presumably reflecting mutated p53. No statistically significant relationship was found between tumor immunopositivity and therapy response or survival. The widespread bax immunopositivity and the apparently low rate of p53 mutations, as suggested by the low rate of p53 immunopositivity, may be related to the presence of prominent apoptosis in Merkel cell carcinoma. The finding of bcl-2 immunopositivity in 76% of the tumors suggests that some of the tumor cells may be resistant to apoptosis-inducing agents.

Adult↗
PubMed1999

CA125 and thyroglobulin staining in papillary carcinomas of thyroid and ovarian origin is not completely specific for site of origin.

AIMS: A 70-year-old woman presented with metastatic psammoma body-rich papillary carcinoma in a supraclavicular lymph node. No primary site was evident. The tumour showed strong staining for CA125 and weak staining for thyroglobulin. Prompted by this case we aimed to assess the reliability of immunostaining for CA125 and thyroglobulin in making the distinction between thyroid and ovarian papillary carcinoma. METHODS AND RESULTS: Nine papillary carcinomas of the thyroid and 17 serous papillary carcinomas of the ovary were stained for CA125 and thyroglobulin, as well as CAM 5.2, LP 34, carcinoembryonic antigen (CEA), S100 and diastase/periodic acid-Schiff. Nine of nine thyroid carcinomas stained for thyroglobulin; in addition CA125 was positive in four of nine. Normal surrounding thyroid also showed some reaction. Seventeen of 17 ovarian serous carcinomas were positive for CA125; in addition one case showed moderately strong staining for thyroglobulin. Mucin stains were positive in 14/17 ovarian serous carcinomas, but negative in all thyroid carcinomas. The other antibodies assessed showed no useful differences in staining frequency. CONCLUSION: Many cases of papillary carcinoma of the thyroid show CA125 staining, and this feature therefore has little positive predictive value for an ovarian origin. Occasional cases of ovarian papillary carcinoma may show staining for thyroglobulin, and this result should therefore be interpreted cautiously.

Aged↗
PubMed1999

Cutaneous necrosis as a terminal paraneoplastic thromboembolic event in a patient with non-Hodgkin's lymphoma.

Thrombotic complications in non-Hodgkin's lymphoma often originate in the large veins. We describe a patient with refractory advanced high-grade lymphoma who presented with the rare complication of extensive cutaneous necrosis due to thrombosis of dermal vessels; there was also a recent new peak of monoclonal IgM-kappa protein. Direct immunofluorescence demonstrated immune deposits with complement in the dermal vessel wall. Based on these observations and on published data, we suggest that these complexes were the trigger for the thrombotic events and that the monoclonal IgM acted as xenoreactive antibodies, initiating a cascade of events. The first step of this cascade was activation of the complement and the membrane attack complex, which caused secretion of IL-1 alpha by endothelial cells, followed by overexpression of tissue factor on the surface of the dermal vessel wall endothelium. Dermal vessel thrombosis was the final event in this cascade.

Humans↗
PubMed1999

Synchronous appearance of keratoacanthomas in burn scar and skin graft donor site shortly after injury.

Skin malignancies can originate in burn scars (Marjolin's ulcer). The most common is squamous cell carcinoma, usually appearing years after injury. Split-thickness skin graft donor sites as a source of malignant transformation are far less frequent and demonstrate a shorter interval between surgery and tumor onset. Keratoacanthomas have rarely been reported to arise in such scars. We describe the simultaneous occurrence of keratoacanthomas on a spontaneously healed second-degree burn on the flank and in the scar of a skin graft donor site on the thigh, 4 months after a 40% total body surface area burn.

Burns↗
PubMed1999

Pilot study of isolated early human follicles cultured in collagen gels for 24 hours.

The human ovarian cortex contains mainly primordial and primary follicles. The ability to mature these follicles in vitro could be of great importance for infertility treatments. Fresh and frozen-thawed ovarian tissue was incubated with collagenase and DNase. Follicles with one layer or an incomplete second layer of granulosa cells were then dissected. The follicles were embedded in collagen gels and cultured with Earle's balanced salt solution, 10% fetal calf serum and 0.5 IU/ml follicle stimulating hormone. Increases in the number of granulosa cell layers and in oocyte size were observed in 40 and 38.7% of the follicles from fresh and frozen-thawed tissue respectively, during a 24 h culture period. All the growing follicles were surrounded by cellular outgrowths. Attempts to culture the follicles longer resulted in deterioration of the follicles and oocyte release. Since our study was purely morphological, further growth parameters, e.g. DNA synthesis, should be examined in the future.

Adult↗