PubMed Health⌕ Search

Biomedical subjects

A Okamura

Publications and source records attributed to A Okamura.

At least 19 recordsLinked to original sources
PubMed1995

Lewis Y antigen expression in hepatocellular carcinoma. An immunohistochemical study.

BACKGROUND: The altered expression of the Lewis blood group-related antigens during malignant transformation can be used clinically as a tumor marker or as a prognostic indicator. The Lewis Y (LeY) antigen, which is one of the Type 2 human blood group-related antigens, also is thought to behave as an oncodevelopmental cancer-associated antigen. In this study, the authors examined the association between human LeY antigen expression and the clinicopathologic features of HCC, including its proliferative activity. METHODS: Forty-six histologically confirmed cases of HCC were studied retrospectively. Liver biopsy specimens from the main tumor of each case were obtained under ultrasonic guidance before treatment was initiated. The formalin fixed, paraffin embedded serial sections were immunostained using a modification of the avidin-biotin-peroxidase complex method, with a primary monoclonal antibody (MoAb) directed against the LeY antigen (BM-1/JIMRO). The relationship between LeY antigen expression and the HCC's proliferative activity was analyzed similarly by immunohistochemical methods using a primary MoAb directed against the Ki-67 antigen (MIB 1). In addition, to clarify the relationship between LeY antigen expression and the histologic heterogeneity within HCC, seven cases of surgically resected HCC also were immunostained. RESULTS: The LeY antigen was detected on the membrane and in the cytoplasm of the cancer cells. Of the 46 HCC cases, 20 (43.5%) expressed the LeY antigen in the tumor cells. There was no correlation between LeY antigen expression and the maximum tumor dimension or the Stage. However, the incidence of LeY antigen-positive cases in poorly differentiated HCCs was found to be significantly higher than that in well or moderately differentiated HCCs (P < 0.01). In resected HCC cases, LeY antigen expression within HCC nodules was frequently greater in the less differentiated tumor than in adjacent differentiated tumor. Moreover, the incidence of LeY antigen expression in alpha-fetoprotein (AFP)-positive (AFP > or = 200 ng/ml) HCC cases was significantly higher than that in AFP-negative (AFP < 200 ng/ml) HCC cases (P < 0.05). Furthermore, the mean value of the Ki-67 labeling index in LeY antigen-positive HCC cases (25.2 +/- 11.3%) was significantly higher than that in LeY antigen-negative HCC cases (9.4 +/- 4.1%) (P < 0.001). CONCLUSIONS: These results suggest that LeY antigen expression correlated closely to the dedifferentiation and proliferative activity of HCC.

Antibodies, Monoclonal↗
PubMed1995

Immunohistochemically demonstrated expression of HLA-DR antigen in colorectal adenocarcinomas and its relation to clinicopathological features.

We studied 148 colorectal adenocarcinomas to clarify any correlation between HLA-DR antigen expression on tumor cells and histopathological features. Paraffin sections of formalin-fixed tissues were stained with HLA-DR antigen using the indirect immunoperoxidase technique. All the tumor tissues were divided into two groups, depending on the incidence of HLA-DR-positive cells (greater and lesser than 50%). Carcinoma tissues with a higher incidence showed less mural invasion, lymphoductal invasion, venous invasion, lymphonodular metastasis, and peritoneal metastasis. Tissues with a high HLA-DR reactivity were more often observed for Dukes' A and B stages, whereas those with a low HLA-DR positivity were frequently Dukes' C and D stages. As for the cumulative survival rate, the group with high HLA-DR expression demonstrated significantly better survival. We speculate that HLA-DR expression by colorectal cancer cells exerts a favorable influence on clinical course.

Adenocarcinoma↗
PubMed1995

Central neurocytoma with hemorrhagic onset.

A case of central neurocytoma with spontaneous intraventricular hemorrhage is reported. A 23-year-old man, 2 years after experiencing intraventricular hemorrhage, developed severe headaches. The magnetic resonance image showed a mixed intense mass in the lateral ventricle with associated hydrocephalus. The tumor mass was totally removed. The tumor was histologically diagnosed as central neurocytoma. Review of the computed tomography taken 2 years ago showed not only the hemorrhage but also a mass in the left lateral ventricle. This emphasizes that central neurocytoma should be considered in the differential diagnosis of patients with either intraventricular hemorrhage or hemorrhagic tumor.

Adult↗
PubMed1995

Diabetes impairs DRG neuronal attachment to extracellular matrix proteins in vitro.

Attachments of dorsal root ganglion (DRG) neurons from streptozotocin (STZ)-induced diabetic and normal C57BL mice to the following substrates were evaluated in vitro: a) poly L-lysine (PL), b) PL + type I collagen (CL-I), c) PL + type IV collagen (CL-IV), d) PL + laminin (LM) and e) PL + fibronectin (FN). After 6 h in culture, there was no significant difference in the average ratio of cells adhesive to PL between the diabetic (74.9%) and normal group of mice (75.6%). In the normal group, the addition of extracellular matrix (ECM) proteins such as CL-I, CL-IV, LM and FN to PL increased the ratios of cell attachment from 75.6% to nearly 90%. In the diabetic group, however, none of these proteins improved the attachment (the ratio changed from 74.9% to nearly 70%). Survival and neurite extension of attached cells after 48 h in culture were not different between the two groups. These results suggest that the cell-surface receptors, which enable DRG neurons to bind to the extracellular matrix proteins, are impaired by diabetes, resulting in being one of the causes of diabetic neuropathy.

Animals↗
PubMed1995

[A case of AIDS patient who was hard to diagnose from an initial symptom of interstitial pneumonitis].

A thirty-six year old male was admitted to the hospital because of fever and dyspnea. On the eighth day the patient turned out to be HIV positive. Although aggressive therapy was performed, the patient died of HIV related disease such as Pneumocystis carinii pneumonitis and CMV infection which led to multiple organ failure seventeen days after admission. We reported a case of AIDS patient who was hard to diagnose from an initial symptom of interstitial pneumonitis.

Acquired Immunodeficiency Syndrome↗
PubMed1995

[A case of incarceration of a right femoral hernia in a very old female with a intriguing clinical course].

The patient was a 94-year-old woman. She was admitted on our hospital for ileus due to incarceration of a right femoral hernia on October 29, 1993. Although an emergency operation was necessary she refused, therefore we continued to have conservative therapy. After repeated persuasion, she agreed the operation which was performed under spinal anesthesia on November 17. The peritoneal cavity was opened through a transverse incision of the lower abdomen. Some bloody ascites was encountered. Part of the jejunum was incarcerated through right femoral canal and was completely obstructed, with ischemic but no necrotic changes. It was excised. She resumed oral intake on the 7th postoperative day and was discharged on the 77th postoperative day. Initially due to her opposition we could not perform the operation, but after persistent persuasion she agreed and survived. Good communications between the doctor and the patient, and of course informed consent, was very important in such cases.

Aged↗
PubMed1995

[Expression of Le(y) antigen in adenocarcinoma and its related lesions of the human uterine cervix].

The natural history and biological behavior of adenocarcinoma and related lesion of the uterine cervix remain controversial issues, but the dynamic alterations in glycosylation in the cancer cells are well known. Recently, it was recently documented that the Ley antigen might be correlated with apoptosis. Over the past eight years, we have encountered 12 cases of invasive adenocarcinoma (AD), 11 cases of early adenocarcinoma (early AD) including 6 adenocarcinoma in situ and 5 microinvasive adenocarcinoma, 16 cases of endocervical glandular dysplasia (EGD) and 10 patients with normal endocervix (control) among 2,165 postoperative cases. Immunohistochemical localizations of Le(y), sialyl Le(x) and epidermal growth factor receptor (EGFR) antigens were examined in serial sections. The localization of Le(y) antigen was predominant in the subcolumnar reserve cells in controls. The localization of sialyl Le(x) was predominant in the perinuclear portion of cells in cases of EGD. The localization of EGFR was presented in cases of tubal metaplasia, tubal type EGD, early AD and AD. These antigens were present in cases of EGD, early AD and AD, with AD cases showing the highest concentrations. To conclude, the presence of the Le(y) antigen might be correlated with differentiation, development and oncogenesis rather than with apoptosis in these lesions, EGD might indicate a precancerous lesion, and localization of the EGFR antigen indicates that tubal metaplasia, tubal type EGD, early AD and AD may have a common origin.

Adenocarcinoma↗
PubMed1995

[Angiocentric lymphoma associated with anemia secondary to parvovirus B19 infection].

A 50-year-old woman was admitted to our hospital in May 1993 because of papules, cervical lymphadenopathy and interstitial pneumonia. Oxygen inhalation and pulse therapy of corticosteroid were started. A biopsy of the left inguinal lymphnode showed T zone enlargement and marked vascularization with polymorphous atypical lymphoblasts, consistent with angiocentric lymphoma (immunohistochemically T cell type). In situ hybridization with EBER-1 did not show association of EB virus. She was subsequently treated with ProMACE-CytaBOM successfully, but anemia had progressed before that treatment showing a reticulocyte count 0/1000, LDH 870 U/l, positive direct Coombs test. Bone marrow aspiration revealed red cell aplasia and the existence of giant pronormoblasts. The hemoglobin dropped to the level of 4.7 g/dl, requiring anabolic steroid and frequent blood transfusion. Parvovirus B19-specific antibodies were negative initially by western blot assay, but IgM antibody appeared after 35 days and IgG after 71 days. In August anemia improved following a reticulocyte burst and recovery of bone marrow erythroblasts. This patient is the first reported case of angiocentric lymphoma complicated with severe anemia, perhaps resulting from autoimmune hemolytic process and parvovirus B19 infection.

Anemia↗
PubMed1995

[A case of primary mediastinal teratocarcinoma in a young girl].

Primary malignant germ cell tumors of the mediastinum are rare neoplasm, almost always occurring in young adult males. This report described embryonal carcinoma in a 13-year-old girl. The patient was checked up at chest X-ray examination of middle-school pupils on June 1989, and was referred to us because of rapid enlargement of the shadow on October 1989. Chest rentogenograms on admission showed a large mass at the anterior mediastinum, and MRI also revealed a multicystic one extending to the right hemithorax and pressing the superior vena cava and the right atrium. Her serum AFP level was high at 211.1 ng/ml. At operation, on November 6, 1989, a large tumor (110 x 95 x 75 mm) was removed completely through median sternotomy. Histological study of the lesion revealed a wide spread of cystic mature teratoma containing some foci of embryonal carcinoma. Positive immunochemical reaction indicated the presence of AFP in these carcinoma cells. She was treated with 13 courses of anti-cancer chemotherapy by various combinations of CDDP, THP-ADR, VP-16, VCR, ACD, CPM, CBDCA, for one postoperative year. She showed clinical improvement and has continued to be free from recurrence now at 52 months after surgery.

Adolescent↗
PubMed1995

[A case of metachronous primary cancer of the lung, rectum and trachea].

We reported a metachronous primary triple cancer of lung, rectum and trachea. Patient was a 64-year-old male, who was admitted with a episode of bloody sputum. A chest X-ray and rentogen tomogram showed a irregularity and narrowing of the upper trachea. Transbronchoscopic biopsy specimen showed squamous cell carcinoma. December '92, trachea was resected in the length of five cartilages and end-to-end anastomosis was performed. Microscopic examination demonstrated a moderately differentiated squamous cell carcinoma with mediastinal lymph node metastasis. Therefore, he received a course of 30 Gy of radiation to the upper mediastinum after surgery. Three years before the tracheal resection, he had undergone left pneumonectomy for moderately differentiated squamous cell carcinoma of the lung. Nineteen months after the pulmonary resection, he had undergone low anterior resection of the colon for the rectum carcinoma.

Adenocarcinoma↗
PubMed1994

[Evaluation of the biological malignancy in hepatocellular carcinoma by argyrophilic nucleolar organizer region (AgNOR) staining--morphological study of AgNOR using image analyzer].

Using the Colloid silver staining technique to reveal AgNOR and immunostaining for anti-PCNA monoclonal antibody, 23 resected specimens with hepatocellular carcinoma (HCC, < or = 3.5cm in diameter) were examined. These cases were divided into two groups; Group A [9 cases without vascular invasion and a satellite nodule] and Group B [14 cases with satellite nodules]. Comparison of AgNOR score, the morphological features of AgNOR (the area and roundness factor of AgNOR) and PCNA labeling index between Group A and Group B was made by a image analyzer (SP-500). The AgNOR scores and PCNA labeling indices of HCCs in Group B were significantly higher than those of HCCs in Group A. And a close correlation was shown between AgNOR score and PCNA labeling index. Further more, the area, form, and distribution of AgNORs within the nucleus were also different in the two study groups. In Group A, many AgNORs were regular and medium-sized brown dots (AgNOR-roundness factor; > or = 80%, AgNOR-area; 1.5-4.5 microns 2). But in Group B, AgNORs showed marked variation in size and form. These results suggest that HCCs with multiple, smaller, irregular, and widely dispersed AgNOR in combination with high AgNOR scores have a more aggressive potential. The morphological features of AgNOR may be useful indicators for evaluating the proliferative activity of HCC.

Antigens, Neoplasm↗
PubMed1994

[Hyperbaric oxygen therapy in the Hokkaido University Hospital].

We surveyed the hyperbaric oxygen therapy during the past seven years in the Hokkaido University Hospital. The mean number of patients was 27 per year. The average number of the therapy was 328 per year. There were neither complications nor accidents attributable to the hyperbaric oxygen therapy. Three representative diseased states hypoxic brain damage, sudden deafness and occlusion of retinal arteries, showed remarkable recovery by this therapeutic modality. A safety standard has been revised in 1991. We have been operating the hyperbaric oxygen therapy according to the revised standard. The inter-departmental approach in this therapeutic modality is mandatory in order to achieve effective outcome.

Female↗
PubMed1994

[Depressant effects of volatile anesthetics on second messenger system in mRNA-expressed Xenopus laevis oocytes].

In this study I attempted to elucidate the depressant effects of volatile anesthetics on inositol trisphosphate (IP3)-mediated signal transduction pathway and to identify the site of action. For this purpose, we used Xenopus laevis oocytes which translated and expressed 5-HT receptors after injection of mRNA isolated from the rat brain. In this system, binding of the agonist to G-protein coupled receptors activates phospholipase C that produces IP3. Mobilization of Ca2+ by IP3 from the storage finally opens Ca2+ dependent Cl- channels. Halothane, isoflurane and methoxyflurane depressed Cl- current elicited by 5-HT. For the further quantitative study, methoxyflurane was used because of its better solubility and less vapor pressure that avoided evaporation of the agent. The 5-HT elicited Cl- current was depressed in a non-competitive fashion. Response were 75, 60, 20% of control in the presence of 0.5, 1 and 3 mM methoxyflurane, respectively. Responses elicited by a pressure-injection of Ca2+ or IP3 remained unchanged in the presence of high concentrations of either halothane, isoflurane or methoxyflurane. These results suggest that the depressant mechanism by volatile anesthetics on the signal transduction pathway involves neither Ca2+ dependent Cl- channel dynamics nor intracellular Ca2+ mobilization by IP3. Changes of microdomain characteristics of the membrane in the presence of anesthetic molecules including membrane-bound proteins and enzyme system may be a main mechanism of action of volatile anesthetics.

Anesthetics↗
PubMed1993

A correlation of argyrophilic nucleolar organizer regions with stages of hepatocellular carcinoma.

BACKGROUND: Recently, the number and morphologic features of argyrophilic nucleolar organizer regions (AgNOR), silver-stained nucleolar organizer regions, were thought to reflect the cellular proliferative activity and the grade of malignancy. In liver diseases, it has been reported that AgNOR scores for hepatocellular carcinomas (HCC) were significantly higher than those for benign and borderline lesions; the scores increased with histologic tumor grade. METHODS: Using the colloid silver staining technique to reveal AgNOR, 64 liver biopsy specimens with HCC were examined of which 14 had Stage I disease, 20 had Stage II, 14 had Stage III, 10 had Stage IVA, and 6 had Stage IVB (by International Union Against Cancer criteria). RESULTS: AgNOR in nuclei were divided into two types. Type 1 (T1-NOR) contained large and medium-sized brown dots with well-defined margins. Nucleoli were included in this type. Type 2 (T2-NOR) had fine black single dots and clusters without well-defined margins outside T1-NOR, but within the nucleus. The size and irregularity of T1-NOR changed with the progress of cancerous stages. The increase in the number of T2-NOR contributed preponderantly to the overall increase in Ag-NOR scores. CONCLUSIONS: These results suggest that HCC with smaller and/or irregular T1-NOR in combination with high T2-NOR scores have a more aggressive potential. AgNOR may be useful indicators for evaluating the progress of HCC.

Carcinoma, Hepatocellular↗
PubMed1993

Zollinger-Ellison syndrome and pheochromocytoma. Report of a case.

A 49-year-old woman was diagnosed in 1985 as having pheochromocytoma because of hypertension with high levels of plasma catecholamine concentration and 24-hour urine excretion of vanillyl-mandelic acid and metanephrine together with a right adrenal mass. The excised tumor cells had fine granular basophilic cytoplasm with argyrophilic granules by Grimelius' method. Four years later, she was diagnosed as having a duodenal bulb ulcer. Serum gastrin showed an abnormally high level of 1900 pg/ml. Abdominal echogram and computed tomography revealed a hypoechoic lesion in the pancreas and intrahepatic multiple tumors. A needle biopsy specimen of the liver tumor was compatible with the histology of metastatic islet cell tumor. A diagnosis of Zollinger-Ellison syndrome was made due to malignant gastrinoma with multiple liver metastases. The patient had no family history of endocrinological or neoplastic disorders. The present case indicates the possibility that pheochromocytoma and gastrinoma, that is, endocrine tumors characteristic of multiple endocrine neoplasia (MEN) I and MEN II, may be coincident even in a person without MEN. A continued awareness of previously rare or undescribed manifestations is important in patients with islet cell tumors or pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1993

Epstein-Barr virus related gastric cancer in Japan: a molecular patho-epidemiological study.

Epstein-Barr virus (EBV) involvement in gastric carcinoma has been demonstrated by the presence of EBV genomes and EBV-encoded small RNA (EBER) in the carcinoma cells, monoclonal proliferation of EBV-infected carcinoma cells and elevated antibody titers. The present study was conducted to investigate the prevalence of EBV involvement among gastric carcinomas observed in nine Japanese cities with varying gastric cancer rates. In situ hybridization of EBER-1 was applied to paraffin sections from 1848 carcinomas observed in 1795 cases and EBV involvement was detected based on uniform hybridization in carcinoma cells. Epstein-Barr virus was detected in 6.6% of lesions and 6.7% of cases. The rate of EBV involvement did not vary significantly for each city and there was no correlation with underlying gastric cancer mortality rates. Thus, geographic variation of gastric cancer rates within Japan cannot be explained in terms of EBV involvement. Epstein-Barr virus-related gastric carcinoma is one of the most common EBV-related tumors in Japan. The involvement of EBV was significantly more frequent among males than among females, mainly for cancers occurring in the upper and middle part of the stomach, and exhibited more variation by cell type among males. These observations suggest that other factors yet to be discovered may modulate the causal role of EBV in gastric carcinogenesis.

Adolescent↗