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Biomedical subjects

A Okamura

Publications and source records attributed to A Okamura.

At least 127 records · Page 7Linked to original sources
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↗
PubMed1995

[A case of renal capsular liposarcoma].

A 53-year-old woman was admitted to the Department of Internal Medicine at our hospital with the primary complaint of pyrexia. Abdominal echography and computed tomography (CT) detected a right renal tumor, and the patient was transferred to our department. Angiography revealed a hypovascular tumor. The main nutrient vessels supplying the tumor were the superior and inferior capsular arteries, which arose from the renal artery. A right renal capsular tumor was suspected from these findings, and radical nephrectomy was performed. Histopathological examination revealed a pleomorphic liposarcoma. Therefore, the patient was given 50 Gy of radiation postoperatively. This is the 14th case of a primary liposarcoma of the renal capsule reported in Japan.

Female↗
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↗
PubMed1993

[The left ventricular force-length relationship in patients with heart failure].

A new contractility index (Ec) is proposed based on the slope of the left ventricular (LV) end-systolic force-length relationship. The Ec values of normal human hearts are relatively constant. The present study investigated the Ec values of 16 cases of heart failure in 11 patients with old myocardial infarction and 5 with dilated cardiomyopathy in NYHA functional class 1 to 3. The LV end-systolic pressure (Pes) and dimension (Des) were estimated simultaneously by intraarterial cannulation and LV echocardiography. The LV pressure decreased from 111 +/- 17 to 90 +/- 14 mmHg after intravenous infusion of nitroglycerin. The LV Fes-Des relationship was found to be nearly linear and the slope (Ec) and extrapolated dimension intercepts (Do) were obtained as 60 +/- 22 g/cm and 2.7 +/- 1.2 cm, respectively. The values of Ec and Do were both proportional to the baseline Des value. Our model predicts that the Ec value reflects intracellular peak Ca2+ concentrations ([Ca2+]) of the myocardium and/or myosin ATPase activity. The present results suggest that the working myocardium of a failing heart increases [Ca2+] and/or myosin ATPase activity to compensate for depressed LV pump function due to myocardial damage.

Adult↗
PubMed1993

[Neoadjuvant chemotherapy effective for small cell lung cancer in a nephrectomized patient].

A 67-year-old man, who was nephrectomized due to renal cell cancer 4 years ago, was admitted to examine a mass shadow in the right middle lung field. He was diagnosed as small cell lung cancer with TBLB. Because of impaired renal function, he was treated with CBDCA (300 mg/m2, day 1), THP (30 mg/m2, day 1) and oral etoposide (25 mg/body, for 21 days) without any renal complications. After 3 courses of chemotherapy, the lung CT showed scar lesion despite the disappearance on the chest X-ray, and a right lower lobectomy was performed. Malignant cells remained in the scar lesion, but not in the lymph nodes. These findings suggested the effectiveness of neoadjuvant chemotherapy. This newly-designed chemotherapy procedure is necessary for patients with renal complications.

Aged↗
PubMed1993

[Diagnostic vitrectomy for chronic uveitis].

Uveitis is diagnosed by ophthalmologic and systemic examination, but it may be difficult to diagnose accurately in some chronic cases. We performed diagnostic and therapeutic vitrectomy for chronic uveitis in 6 eyes of 4 patients, and examined vitreous specimens with immunohistochemical staining. Visual acuity improved in all cases due to clearing up of the vitreous cells. One patient had sarcoidosis, one had B cell malignant lymphoma (ocular reticulum cell sarcoma), and two had reactive lymphoid hyperplasia. Vitrectomy for chronic uveitis is useful for diagnosis and improvement of vision, and we recommend immunohistological staining of vitreous specimens. Particularly, when intraocular lymphoma is suspected, vitrectomy must be performed early.

Aged↗
PubMed1993

[Malignant lymphoma following operation and chemotherapy of small cell lung carcinoma].

A 57-year-old man was admitted with systemic lymphadenopathy. He had undergone resection for small cell lung carcinoma and received chemotherapy 6 years previously. A specimen of swollen lymph nodes showed malignant lymphoma. Surface marker analysis revealed the lymphoma to have the same characteristics as lymphoblastic lymphoma (LBL). He received combination chemotherapy, but marked resistance was recognized. His condition deteriorated rapidly and died. Having the characteristics of LBL on lymphoma at an older age and severe drug-resistance suggests that this lymphoma might have been a second malignancy due to preceding chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Correlative study of behavior and synaptic events during halothane anesthesia in the lamprey.

Behavioral anesthetic effects of halothane were compared with neurophysiological data obtained from monosynaptically coupled, single axon-giant neuron pairs in the isolated central nervous system of the lamprey in vitro. Based on the assumption that the number of halothane molecules at the site of anesthetic action is determined by molar concentration of the bath, depths of anesthesia were characterized in terms of synaptic events. The concentration producing anesthesia in 50% (AC50) and 95% (AC95) of the animals were 0.32 and 0.51 mM, respectively. With these concentrations, the depression of glutamate (GLUT)-mediated synaptic excitation remained less than 50%. Maximum suppression of the excitatory synaptic transmission was observed in the presence of 1.7 mM halothane which would be equivalent to the inhalation of 5.5% of this agent at 37 degrees C. At these concentrations, postsynaptic membranes did not respond to the bath-applied GLUT agonists. The decrease of agonist-induced responses to almost the same extent as excitatory postsynaptic potential (EPSP) amplitudes in the presence of halothane argues against a presynaptic mechanism affecting transmitter release. Persistent voltage-gated Na+ channel function at concentrations less than 2.4 mM is evidence against the involvement of this mechanism at these levels of anesthesia. The present results suggest that with depths between AC50 and AC95, anesthesia is associated with a partial reduction of sensitivity of the postsynaptic membrane to the excitatory amino acid transmitters.

Anesthesia, Inhalation↗
PubMed1992

Keratin profiles in normal/hyperplastic prostates and prostate carcinoma.

Immunoreactivities in 25 cases of prostatic adenocarcinoma and 10 normal/hyperplastic prostates were investigated in methacarn-fixed, paraffin-embedded serial sections using a panel of nine anti-keratin monoclonal antibodies (mAbs); 34 beta E12, CK8.12, 312C8-1, CK4.62, RPN1165, RPN1162, 35 beta H11, CK5, M20, and one of anti-actin mAb, HHF35. In normal/hyperplastic prostates, RPN1162, 35 beta H11, CK5 and M20 stained luminal cells without staining basal cells, and 34 beta E12, CK8.12 and 312C8-1 stained basal cells but not luminal cells. Other mAbs, CK4.62 and RPN1165, stained basal cells as well as luminal cells. All of the mAbs labelling luminal cells stained cancer cells with variable frequencies in a manner unrelated to the grade of tumour differentiation. Of the prostate cancer cases 92% were scored positive with M20, 84% with 35 beta H11, 80% with CK5, 68% with CK4.62, 60% with RPN1165 and 4% with RPN1162. However, basal cell-specific keratins labelled with 34 beta E12, CK8.12 and 312C8-1 were totally negative in the cancer cells. HHF35 showed no labelling in normal, hyperplastic or neoplastic epithelial cells of the prostate. Our findings indicate that the major part of the cells of prostatic adenocarcinomas have keratin phenotypes similar to luminal cells but not basal cells, and that no myoepithelial differentiation can be detected in epithelial cell of the prostate. Thus, mAbs for keratins facilitate the identification of epithelial cell phenotypes in normal, benign and malignant conditions of the prostate.

Adolescent↗