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Biomedical subjects

K Oka

Publications and source records attributed to K Oka.

At least 577 records · Page 32Linked to original sources
PubMedDate not supplied

Chiral resolution of four major flavanones in post-administrative urine of Chinese herbal medicines by HPLC on macroporous silica gel coated with cellulose tris(3,5-dimethylphenylcarbamate).

Direct chiral resolution of four major flavanones recovered from post-administrative urine of the traditional Chinese medicines Daisaiko-to and Shosaiko-to was achieved by high-performance liquid chromatography (HPLC) on macroporous silica gel coated with cellulose tris(3,5-dimethylphenylcarbamate), Chiralcel OD. Chromatographic conditions were optimized so as to attain satisfactory enantiomeric resolution of the polysubstituted flavanones. Urinary liquiritigenin and naringenin were considerable mixtures of R and S-enantiomers, while S-enantiomers of dihydrowogonin and dihydrooroxylin A were predominantly excreted. Our chiral HPLC techniques can be applied to pharmacokinetical evaluation of the chiral flavanone enantiomers following oral administration of the herbal medicines.

Administration, Oral↗
PubMedDate not supplied

Benign clear cell tumor of the lung.

A 49-year-old woman presented with a solitary pulmonary nodule in the right lung. The tumor was well circumscribed and showed a reddish brown cut surface. It showed a diffuse growth pattern of polygonal cells with clear abundant cytoplasm and distinct cell border around thin-walled vascular spaces and sinusoid-type vessels. Based on morphological findings, the patient was diagnosed as having benign clear cell tumor of the lung. Silver impregnation and PAM stains showed fine reticular fibers continuously surrounding the vessels and individual neoplastic clear cells. Strong immunostaining for type IV collagen was observed surrounding all the individual clear cells. A few clear cells were positive for HMB-45 and NCAM 123C3 (CD56). Electron microscopically, clear cells had numerous membrane-bound glycogen granules and a large amount of non-membrane-bound glycogen. The neoplastic cells were surrounded by external lamina and cytoplasmic processes. The neoplastic clear cells showed morphologic features seen in pericytes, melanocytic cells, and neuroendocrine cells.

Adenocarcinoma, Clear Cell↗
PubMedDate not supplied

Mechanisms and mediators of psychological stress-induced rise in core temperature.

OBJECTIVE: Despite numerous case reports on "psychogenic fever," it remains uncertain how psychological stress raises core temperature and whether the rise in core temperature is a real fever or a hyperthermia. This article reviews studies on the psychological stress-induced rise in core temperature (PSRCT) in animals with the aim to facilitate studies on the mechanisms of so-called psychogenic fever in humans. METHODS: To address this question, we reviewed the mechanisms and mediators of the PSRCT and classic conditioning of the fever response in animals. RESULTS: The PSRCT is not due to the increased locomotor activity during stress, and the magnitude of the PSRCT is the same in warm and cold environments, indicating that it is a centrally regulated rise in temperature due to an elevated thermoregulatory "set point." The PSRCT caused by conventional psychological stress models, such as open-field stress, is attenuated by cyclooxygenase inhibitors, which block prostaglandin synthesis. On the other hand, the PSRCT elicited by an "anticipatory anxiety stress" is not inhibited by cyclooxygenase inhibitors but by benzodiazepines and serotonin Type 1A receptor agonists. The febrile response can be conditioned to neutral stimuli after paired presentation with unconditioned stimuli such as injection of lipopolysaccharide, a typical pyrogen. CONCLUSIONS: Most findings indicate that the PSRCT is a fever, a rise in the thermoregulatory set point. The PSRCT may occur through prostaglandin E2-dependent mechanisms and prostaglandin E2-independent, 5-HT-mediated mechanisms. The febrile response can be conditioned. Thus, these mechanisms might be involved in psychogenic fever in humans.

Animals↗
PubMedDate not supplied

Vulvar Paget's disease with underlying adenocarcinoma simulating breast carcinoma: case report and review of the literature.

We report a case of extramammary Paget's disease with underlying adenocarcinoma simulating breast carcinoma of the vulva. An 82-year-old woman was found to have a 5 x 3-cm bulky tumor located in the left labium major, infiltrating to the clitoris, left labium minor, and left lateral tissue of the vulva. Small biopsy of the vulva showed intraepidermal proliferation of Paget cells. The patient underwent wide local excision of the vulvar tumor and dissection of left inguinal lymph nodes. Histopathological examination of the resected specimens revealed that Paget cells were distributed singly or tended to form small nests in the epidermis, and that association of these cells with the underlying carcinoma invading to the subcutis could be seen. The underlying carcinoma was composed of squamoid solid nests with central necrotic debris, mimicking 'comedocarcinoma' of the breast. In other areas, the tumor cells were present in tubular formations and solid cords reminiscent of invasive ductal carcinoma of the breast. Immunohistochemically, the Paget cells and the underlying carcinoma cells were positive for carcinoembryonic antigen, epithelial membrane antigen, estrogen receptors, and glandular keratins except for CK 20. We speculate that our case is vulvar Paget's disease presenting as a manifestation of underlying breast carcinoma of the vulva, which might have arisen from either the ectopic breast tissue or anogenital mammary-like glands.

Adenocarcinoma↗
PubMedDate not supplied

Prognostic significance of c-erbB-2/HER2 expression in advanced uterine cervical carcinoma with para-aortic lymph node metastasis treated with radiation therapy.

This paper looks at whether c-erbB-2/HER2 expression in uterine cervical carcinoma before treatment is a predictive parameter of prognosis in patients with para-aortic lymph node metastasis (PALN) in advanced disease after treatment with radiation therapy (RT). Twenty-one patients with PALN at the first visit and/or during follow-up and treated with RT for PALN lesions were studied. Their clinical stages were IIIB or greater and they were referred to the National Institute of Radiological Sciences Hospital for RT between 1987 and 1995. They consisted of 12 patients with PALN detected at the first visit and nine with PALN detected during the follow-up period. All patients had no distant metastasis except PALN. They were treated with a combination of external whole pelvis and intracavitary irradiation to the primary pelvic lesions. The PALN was treated with external irradiation alone with anterior-posterior parallel opposed fields and anterior oblique fields or anterior-posterior parallel opposed oblique fields. The average total dose to PALN was 53.3 Gy (40-61Gy). Tissue samples were obtained from cervical tumors (primary lesions) before RT. Immunohistochemical staining was performed using anti-c-erbB-2/HER2 monoclonal antibody for conventional paraffin sections. c-erbB-2/HER2 positive staining was observed in cancer membrane and cytoplasm. Nine specimens were positive for c-erb-B2/HER2 and the total positive rate was 43%. The 5-year survival rate was 38% for all patients. The 5-year survival rate of the c-erbB-2/HER2 positive patients was 28%, representing a trend toward poorer prognosis than the 52% of negative patients (P = 0.10). Multivariate analysis using Cox proportional hazards model showed that c-erbB-2/HER2 was an independent prognostic factor (P = 0.024). The present study suggests that c-erbB-2/HER2 expression of cervical tumors might be a predictive parameter of prognosis after radiation therapy for PALN of very advanced uterine cervical carcinoma patients.

Adult↗
PubMedDate not supplied

Intracerebroventricular injection of tumor necrosis factor-alpha induces thermal hyperalgesia in rats.

To investigate the role of tumor necrosis factor-alpha (TNF-alpha) in the brain in nociception, we injected recombinant human TNF-alpha (rhTNF-alpha; 1 pg-10 ng/rat) into the lateral cerebroventricle (LVC) in rats and observed the changes in paw withdrawal latency to radiant heat by using the plantar test for 90 min after injection. LCV injections of TNF-alpha at doses of 10 pg, 100 pg and 1 ng reduced paw withdrawal latency, showing a maximal response at a dose of 10 pg which peaked 60 min after injection. TNF-alpha at doses of 1 pg and 10 ng had no effect on nociception during the test period. The TNF-alpha (10 pg)-induced reduction in paw withdrawal latency was blocked by simultaneous injection of diclofenac (1 ng), a cyclooxygenase inhibitor, or interleukin-1 receptor antagonist (IL-1 ra, 10 ng). LCV injection of neither diclofenac (1 ng) nor IL-1 ra (10 ng) had any effect on nociception by itself. The results suggest that TNF-alpha in the brain induces thermal hyperalgesia and that the brain TNF-alpha-induced hyperalgesia is mediated by the central action of interleukin-1 and activation of the cyclooxygenase pathway of the arachidonate.

Animals↗
PubMedDate not supplied

Histopathology of the brain vascular network in moyamoya disease.

There is an unusual vascular network at the base of the brain in patients with moyamoya disease. We detected various histologic lesions in the perforating arteries of 22 patients. Vessels showing rupture ranged from 50 to 530 microns in diameter; they were dilated, some had fibrin deposits in the wall, fragmented elastic laminae and attenuated media. Non-ruptured perforating arteries (diameter 200 to 550 microns) revealed microaneurysm formation, focal fibrin deposits and marked attenuation of the wall thickness with diminution of the elastic lamina. These changes seem to predispose to rupture of perforating arteries. Stenotic changes such as fibrous intimal thickening, collapse of the lumen and thrombosis were detected in 14 out of 22 cases. Morphometric analysis of perforating arteries indicated that arteries showing extreme degrees of stenosis or dilatation were more frequent in the patients with moyamoya disease than in the control cases. Dilative arteries were more frequent in the young patients and stenotic vessels were, in contrast, less frequent in the young patients.

Adolescent↗
PubMedDate not supplied

Cervico-cephalic arterial thrombi and thromboemboli in moyamoya disease--possible correlation with progressive intimal thickening in the intracranial major arteries.

Ninety-two thrombi and/or thromboemboli of cervico-cephalic arteries were confirmed histopathologically in 16 out of 22 patients with moyamoya disease. Included were 74 white thrombi mainly composed of fibrin and platelets, 9 organized thrombi and 9 mixed thrombi containing red blood cells. Thirteen microthrombi and one organized thrombus were located in the cervical arteries. Seventy-eight thrombi were present in the intracranial major arteries. Sixty-five were white microthrombi attached to the luminal surface of the arteries. The intracranial microthrombi were most frequently observed at the distal ends of the internal carotid arteries (29 thrombi). The fibrous thickening of the intima and edema in the innermost luminal surface were the most common vascular alterations associated with the thrombus formation. In two patients, thrombus formation was associated with fissure of the thickened intima and a dissecting aneurysm. We concluded that in patients with moyamoya disease the thrombi may be closely related to the development of intimal thickening in the intracranial arteries, particularly at the distal ends of the internal carotid arteries.

Adolescent↗
PubMedDate not supplied

Successful delivery in a case of essential athrombia.

A successful delivery in a 26-year-old Japanese woman with essential athrombia was reported. A diagnosis of essential athrombia was made by clinical and laboratory features including bleeding tendency, prolonged bleeding time, normal platelet count, normal clot retraction and impaired platelet aggregation induced by ADP. Since the presentation was a frank breech at the end of the 39th week of pregnancy, cesarean section delivery was performed under good hemostatic control with transfusion of 7.3 x 10(11) platelets. No hemorrhagic complication was observed during the puerperium.

Adult↗
PubMedDate not supplied

Primary melanocytoma arising from the thoracic leptomeninges case.

Primary melanocytoma arising from the leptomeninges of the spinal cord is very rare. A surgical specimen of a thoracic meningeal tumor was resected from a 75-year-old woman complaining of gait disturbance was investigated. Magnetic resonance imaging and myelography showed a dumb-bell-type tumor in the subdural space at the 1st to 2nd thoracic vertebrae. The tumor was subtotally resected because of adhesion to the lamina and thoracic medulla. The localized, gelatinous black tumor showed a well-defined margin without dissemination or infiltration. The tumor had a thin capsule and was composed of solid proliferation of neoplastic melanocytes. Neither whorl formation nor foci of palisaded nuclei were observed. The neoplastic cells were of two major types: an epithelioid- or polygonal-shaped type and a spindle-shaped type, and had a large nucleus, a prominent nucleolus, coarse chromatin, and melanin-pigments in their cytoplasm. Only a few mitotic figures were observed. They were positive for HMB-45 and S-100 protein. This case was considered to be primary melanocytoma arising from the thoracic leptomeninges.

Aged↗
PubMedDate not supplied

Clinical evaluation of serum and immunohistochemical expression of SCC and CA19-9 in radiation therapy for cervical cancer.

The prognostic significance of serum level of SCC and CA19-9 (i.e. sr-SCC and sr-CA19-9) and tumor expression of SCC and CA19-9 (i.e. im-SCC and im-CA19-9) were investigated in patients undergoing radiation therapy for cervical cancer. A total of 103 patients comprising 95 squamous cell carcinomas, 3 adenosquamous cell carcinomas and 5 adenocarcinomas, were studied. The tumor expression of SCC and CA19-9 were determined immunohistochemically. The positivity of the patients with abnormal sr-SCC levels for squamous cell carcinoma, adenosquamous cell carcinoma and adenocarcinoma were 87.7%, 50.0% and 40.0%, respectively The 5-year-survival rates of sr-SCC positive and negative patients were 71.1% and 100%, respectively (P > 0.1). The survival rates of im-SCC positive and negative patients were 70.0% and 80.7%, respectively (P > 0.1). The positivity of patients with im-CA19-9 in squamous cell carcinoma, adenosquamous cell carcinoma, im-CA19-9 adenocarcinoma were 29.1%, 66.6%, and 100%, respectively. The 5-year-survival rates of sr-CA19-9 positive patients was 62.5%, poorer than the 77.6% of negative ones (P < 0.1). The survival rate of im-CA19-9 expression positive patients was 92.0%, significantly better than the 70.7% in negative patients (P < 0.05). Although the sr-SCC level just at the end of radiation therapy was not correlated with local control, re-elevation of the SCC was highly associated with early relapse. These results suggested that follow-up of patients by periodical serum examination for these tumor markers is highly useful for the early detection of tumor relapse.

Adenocarcinoma↗
PubMedDate not supplied

Primary hepatic choriocarcinoma--a case report.

A 65-year-old man experienced anorexia and abdominal enlargement and died suddenly 45 days after admission. Multiple necrotic and hemorrhagic tumors were present in the liver (6 kg). The fragile tumor ruptured and a large amount of blood accumulated in the peritoneal cavity. The tumor was composed of cytotrophoblast and syncytiotrophoblast cells. Neoplastic cells were positive for human chorionic gonadotropin and negative for alpha-fetoprotein and carcinoembryonic antigen. The huge tumor directly invaded the entire antrum of stomach. Neoplastic trophoblastic cells proliferated mainly in the serosa and propria muscular layer of the stomach, and tiny cancer nests were observed in many vessels of the submucosa and propria mucosa. The serum alpha and beta human chorionic gonadotropin subunits showed a very high level; 51 ng/mL and 820 ng/mL, respectively. No tumor, cyst or scar was observed in the testes, mediastinum and retroperitoneum, macroscopically and microscopically. Based on these autopsy findings, we diagnosed this patient as having primary hepatic choriocarcinoma.

Aged↗
PubMedDate not supplied

Solid papillary carcinoma of the breast: report of two cases.

Two cases of solid papillary carcinoma of the breast were pathologically studied. Subjects included two female patients: a 76-year-old (Case 1) and a 43-year-old (Case 2). Both cases showed solid and papillary proliferation of spindle cells in expanded ducts, perivascular pseudorosettes, eosinophilic fine granules in an abundant cytoplasm, intracellular mucin production, and positivity for chromogranin A. Case 1 showed an aggregation form involving multiple ducts, admixture of signet-ring like cells, mucin pools, and small and large electron-dense granules and flocculent granules in electron microscopy. Case 2 showed a solitary and compact form in a dilated duct and an interlacing bundle pattern.

Adult↗
PubMedDate not supplied

Cavernous sinus thrombophlebitis caused by sphenoid sinusitis--report of autopsy case.

A 34-year-old man developed fever, headache, nausea, double vision, exophthalmus, ptosis, disturbance of vision and oculomotor nerve palsy. Magnetic resonance imaging and cerebral angiography led to the clinical diagnoses of cavernous sinus thrombophlebitis and suspicion of bacterial aneurysm of the left internal carotid artery, respectively. Peptostreptococcus was detected in blood culture analysis. He died 15 days after admission. Systemic organs showed several septic changes. In particular, the bilateral cavernous sinuses were enlarged and showed severe neutrophilic leukocyte infiltration of the walls and organization, recanalization and abscesses in thrombi. In anterior to the middle cranial fossa, abscess-forming, necrotic, hemorrhagic meningitis, purulent sphenoid sinusitis, pyogenic osteomyelitis of the sphenoid bone, suppurative encephalitis, and inflammatory necrosis of the hypophysis were seen. Based on these findings, we diagnosed the patient with cavernous sinus thrombophlebitis caused by sphenoid sinusitis.

Adult↗
PubMedDate not supplied

Flow cytometric and Ki-67 immunohistochemical analysis of cell cycle distribution of cervical cancer during radiation therapy.

BACKGROUND: Little is known about the cell kinetics of human solid tumors during radiation therapy. MATERIALS & METHODS: Thirty one patients with cervical squamous cell carcinoma were analyzed by flow cytometry and immunohistochemical staining with Ki-67 antibody for tumor cell kinetics in the early period of radiation therapy. RESULTS: The G0/G1 fraction was significantly larger in stage 3 disease than in stage 2 disease. During radiation therapy, a decrease in the G0/G1 fraction and an increase in the S fraction were observed in stage 3 but not in stage 2 disease. Two reversal patterns of change in the cell cycle appeared in the early period of radiation therapy. The S phase fraction decreased significantly as the G0/G1 fraction of pre-treatment tumors became smaller than 70%, whereas it increased as the G0/G1 fraction became larger than 70%. The S fraction decreased significantly as Ki-67 growth fractions of pre-treatment tumors became greater than 30%, but on the contrary, it increased as the Ki-67 growth fraction became smaller than 30%. Only 2 of 23 patients showed a significant increase of the G2M fraction, reflecting the presence of the G2 block. The Ki-67 growth fraction increased about 26 % at 9 Gy compared with the growth fraction before treatment. Tumors which responded well showed higher G0/G1 fractions and lower S fractions than those which responded badly. CONCLUSION: The change of cell cycle parameters of the tumors during radiation therapy suggests that two reversal patterns of changes in cell kinetics take place in the early period of radiation therapy, which may have a potential impact in the modification of radiation therapy.

Adult↗
PubMedDate not supplied

Antitumor activity of orally administered SMANCS, a polymer-conjugated protein drug, in mice bearing various murine tumors.

The antitumor activity of an oily formulation of SMANCS (oily SMANCS), which is a product of conjugation between a proteinaceous antitumor antibiotic neocarzinostatin and poly (styrene-co-maleic acid), after oral administration to mice inoculated with various murine tumors was investigated. BALB/c mice, inoculated either s.c. or i.p. with allogeneic (sarcoma-180) or syngeneic (RL male 1 leukemia and Meth A fibrosarcoma) tumors, were treated with oily SMANCS orally or with an aqueous formulation of SMANCS (aqueous SMANCS) i.v. or i.p. Oral administrations of oily SMANCS or i.v. administrations of aqueous SMANCS to mice bearing three types of tumors in the ascites form resulted in a weak inhibition of tumor growth as compared to the complete inhibition of these tumors by aqueous SMANCS administered i.p. In mice bearing solid tumors, tumor growth was inhibited by 63-82% when a 10 mg/kg dose of oily SMANCS was administered orally to these mice. The antitumor potential of oily SMANCS administered orally was comparable to that obtained from solid tumor-bearing mice receiving i.v. doses of aqueous SMANCS. These results suggest that the oral administration of oily SMANCS to mice bearing various solid tumors inhibits the tumor growth as effectively as aqueous SMANCS administered i.v.

Administration, Oral↗