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Biomedical subjects

K Okada

Publications and source records attributed to K Okada.

At least 1,171 records · Page 65Linked to original sources
PubMed1989

Heterogeneity of big-big hPRL in hyperprolactinemia.

Sera from a patient with macroprolactinoma (case 1) and from a hyperprolactinemic woman with regular menstruation (case 2) were analyzed for prolactin activity by gel filtration using Sephadex G-100, Sephadex G-200 and TSK G3000SW columns. The chromatographic profile by Sephadex G-100 showed that the percentage of immunoreactive big-big hPRL was 10.7% in case 1 and 64.1% in case 2. On Sephadex G-200 and TSK G3000SW columns, the molecular weight of big-big hPRL was estimated to be more than 500,000 daltons (big-big1 hPRL) in case 1 and approximately 250,000-300,000 daltons (big-big2 hPRL) in case 2. Big-big1 hPRL in case 1 was converted to big and little hPRLs when the serum was treated with 2-mercaptoethanol (2-ME), but part of the big-big2 hPRL in case 2 was converted to a larger molecule. Radioactive big-big hPRL generated by mixing labeled hPRL with the serum from case 1 was eluted with the void volume on Sephadex G-100 column and was not converted to the other molecular forms after 2-ME treatment. There were two radioactive big-big hPRL on TSK G3000SW column and these estimated molecular weights were more than 300,000 daltons. The data demonstrated the existence of at least two forms of big-big hPRL in the serum and indicated that radioactive big-big hPRL may be different from these hPRLs in the serum.

Chromatography, Gas↗
PubMed1989

A small aneurysmal bone cyst restricted to the cortical bone of the femur resembling so-called subperiosteal giant cell tumor or subperiosteal osteoclasia.

We report a 16-year-old Japanese girl with a cystic lesion restricted to the cortical bone under the periosteum of the diaphysis of the left femur. Roentgenograms showed a long, oval translucent lesion in frontal view and an eccentric erosive lesion in lateral view. Computed tomography showed a distinct intracortical lesion. The lesion, which was excised en bloc, measured 3 x 2 x 2 cm. The outer layer of the cortical bone was eroded eccentrically. From the margin of the eroded bone, thin fragile bony tissue and preserved periosteum extended like the roof of a dome. Multicystic structures, filled with blood, were lined with fibrous granulation and occasional giant cells. Histologically, this lesion falls within the category of aneurysmal bone cyst. However this case is of a rare type, since the lesion was relatively small, and showed a very specific intracortical location, in marked contrast to typical aneurysmal bone cyst. Additionally, this lesion is similar to so-called subperiosteal giant cell tumor or subperiosteal osteoclasia described in the literature.

Adolescent↗
PubMed1989

An electron microscopic study of hepatic angiomyolipoma.

Three cases of hepatic angiomyolipoma, each composed of an intimate mixture of numerous abnormal blood vessels and various-sized fat, spindle and/or epithelioid cells, are presented along with the findings of an electron microscopic study. The spindle cells were confirmed to be smooth muscle by immunohistochemical staining for desmin and by their ultrastructural characteristics. The mature fat cells, smooth muscle cells, immature short spindle cells apparently intermediate or transitional between the former two cell types, and the epithelioid cells were observed adjacent to the endothelial cells. Ultrastructurally, the epithelioid cells were characterized by unusual cytoplasmic organelles such as myofilaments having focal densities and dense attachments, numerous large electron-dense bodies, and a large number of glycogen particles and lipid droplets. Therefore, it is considered that the immature short spindle and epithelioid cells in hepatic angiomyolipoma might be primitive mesenchymal cells having an ability to differentiate toward both smooth muscle and fat cells.

Adult↗
PubMed1989

Protective effect of recombinant murine granulocyte-macrophage colony-stimulating factor against Pseudomonas aeruginosa infection in leukocytopenic mice.

The effects of recombinant murine granulocyte-macrophage colony-stimulating factor (rmGM-CSF) against Pseudomonas aeruginosa infection in ICR mice were investigated. Mice were treated with cyclophosphamide (CPA) and were then injected intraperitoneally with rmGM-CSF three times daily, beginning on the day after CPA treatment, for 7 days. The number of peripheral blood leukocytes in both CPA- and rmGM-CSF-treated mice and control CPA-treated mice reached a nadir on day 4, when P. aeruginosa was injected intraperitoneally. The administration of rmGM-CSF significantly increased the proportion of survivors among mice infected with a lethal dose of P. aeruginosa. This effect was further analyzed by monitoring sequential changes in leukocyte count and bacterial growth in various organs. The number of bacteria in the peritoneal cavities, peripheral blood samples, and livers of GM-CSF-treated mice decreased to an undetectable level after a transient increase, and the number was significantly lower than that in control mice. In GM-CSF-treated mice, the neutrophil levels in peripheral blood started to increase 5 days after CPA administration and were consistently higher than those in controls. Furthermore, the neutrophils in GM-CSF-treated mice were more mature morphologically. Thus, the prophylactic effect of rmGM-CSF against P. aeruginosa infection may result from a rapid recovery of myelopoiesis and a partial enhancement of mature neutrophil function.

Animals↗
PubMed1989

Phorbol esters and arginine vasopressin in vascular smooth muscle cell activation.

Vascular smooth muscle cell (VSMC) contraction is the result of several interacting mechanisms. In this study such interactions in rat aortic VSMC in culture were examined with a focus on the role of protein kinase C-mediated mechanisms. The change in shape of VSMC was used as a functional parameter representative of contraction. The protein kinase C agonist, phorbol myristate acetate (PMA), and arginine vasopressin (AVP) induced a dose-dependent, progressive change in VSMC shape. The effects of PMA differed from AVP in the delay time necessary to reach the plateau of the response and in the absence with PMA of a transient rise in cytosolic free Ca2+ [( Ca2+]i). The effect of PMA was potentiated by the Ca2+ ionophore, ionomycin, and involved a verapamil-inhibitable transmembrane Ca2+ transport system. Protein kinase C inhibition by either isoquinolin-sulfonyl-O-2-methylpiperazine or protein kinase C desensitization significantly reduced the cell shape change induced by either PMA or AVP. In the case of AVP, this inhibitory effect occurred without affecting the [Ca2+]i transient. Therefore, the [Ca2+]i transient appears to be independent of acute protein kinase C regulation, since it is apparently not affected by the absence of protein kinase C activity. Protein kinase C activation by PMA produced intracellular alkalinization that is blocked by the sodium transport antagonist, amiloride. Amiloride also blocked the cell shape change induced by PMA or AVP. The intracellular alkalinization, however, was not necessary for the cell shape change to occur. Specifically, with the use of VSMC preincubated with fetal calf serum, PMA did not induce cellular pH changes but still produced cell shape changes.

Amiloride↗
PubMed1989

Correlation between carotid blood flow and brain atrophy in patients with multi-infarct dementia.

The relation between carotid blood flow measured by Doppler spectrum analysis and brain atrophy on computed tomography (CT) was studied in 22 subjects with multiple lacunar cerebral infarctions. The subjects were divided into two groups, 7 patients with multi-infarct dementia (MID) (mean age 73 years) and 15 nondemented lacunar stroke subjects (NDLS) (mean age 66 years), according to DSM III criteria. All subjects had a score of 7 points or more on Hachinski's ischemic score and showed no carotid artery stenosis. Systolic peak frequency of the common carotid artery (CCA) was measured by Doppler spectrum analysis (Angioscan II). Brain atrophy was measured quantitatively on CT images by two-dimensional measurement using a digitizer. Peak frequencies were lower in MID than in NDLS. Brain atrophy was more severe in MID than in NDLS. There was a significant correlation between peak frequencies and brain atrophy in all subjects. These results indicate that CCA blood flow may reflect brain function in patients with multiple lacunar infarctions.

Aged↗
PubMed1989

Multiple marker evaluation in prostatic cancer using prostatic specific antigen, gamma-seminoprotein and prostatic acid phosphatase.

Serum prostatic specific antigen (PA), gamma-seminoprotein (gamma-Sm) and prostatic acid phosphatase (PAP) were evaluated in 141 patients with prostatic cancer, 121 of whom were newly diagnosed. Of the 121 untreated patients, 77, 71 and 67% were detectable by the PA, gamma-Sm and PAP markers, respectively. PA was equally or more sensitive in all stages than the other two markers. Using the benign prostatic hypertrophy group (131 patients) as a negative control, the specificities of PA, gamma-Sm and PAP were 89, 76 and 83%, respectively. Combination of PA, gamma-Sm and PAP increased sensitivity to 86%, especially in localized disease (stages A, B and C) to 74%, but did not improve specificity (67%) or efficiency (76%). During the follow-up period of 1-53 months, 24 of 141 patients with prostatic cancer had disease progression. All serial levels of gamma-Sm, PA, and PAP were positive in 17, 12 and 10 of the 24 patients within 6 months prior to detectable disease progression. gamma-Sm appeared to be more sensitive than the other two markers for early detection of disease progression. These results suggest that PA and gamma-Sm are reliable markers for detection and monitoring of prostatic cancer.

Acid Phosphatase↗
PubMed1989

Cytogenetic survey of subfertile males in Japan.

Chromosomal analysis of 554 consecutive Japanese male patients attending a subfertility clinic revealed 18 (3.2%) major chromosomal aberrations. The incidence of sex chromosomal anomalies and autosomal anomalies is 1.3 and 2.0%, respectively, which is significantly higher than that for the general population. All 7 sex chromosomal anomalies were found among the azoo- or oligozoospermic patients, while the incidence of autosomal anomalies for the normozoospermic patients was statistically similar to that for the azoo- or oligozoospermic patients. Therefore, cytogenetic analysis is recommended not only for patients with reduced sperm density but also for subfertile patients with normozoospermia.

Adult↗
PubMed1989

Spontaneous regression of bovine cutaneous leukosis.

Biopsies of skin from a 2-year-old heifer with spontaneously regressing dermal leukosis were examined. The heifer was not infected with bovine leukemia virus and was negative for tumor-associated antigens of enzootic bovine lymphosarcoma. By hematological standards for bovine leukemia, the heifer was positive at about 60 days post-occurrence of the disease (POD). At 53 days POD, lymphoblastic neoplastic cells in the dermis reacted with anti-T lymphocyte monoclonal antibody by the avidin biotin peroxidase complex method. The cells had intracytoplasmic clustered dense bodies under electron microscopy. From 53 to 83 days POD, figures of the transepithelial elimination (TE) against neoplastic cells and perivascular infiltration of small lymphocytes were in the dermis. Small lymphocytes reacted with anti-T lymphocyte monoclonal antibody. At necropsy there were no neoplastic lesions; there were flat lymph node-like tissues in the subcutis. Many germinal centers were seen in the lymphatic organs. Blood lymphocytes at 46 days POD were stimulated by phytohemagglutinin-P and concanavalin A. Sera, taken until 75 days POD and at necropsy, showed an inhibitory effect on mitogen-induced blastogenesis of normal bovine lymphocytes. These results suggested the existence of a spontaneous regressive mechanism against neoplastic lesions by TE and tumor immunity.

Animals↗
PubMed1989

Effect of monensin on secretion of t-PA from melanoma (Bowes).

The secretion of tissue-type plasminogen activator (t-PA) from melanoma cells (Bowes) was investigated with or without monensin treatment. Monensin inhibited secretion of t-PA from the cells to the medium in a dose-and time-dependent manner. The inhibition was accompanied by an intracellular accumulation of t-PA. Electrophoretic enzymography of the cell homogenate showed the main lytic zone at 72 kDa, which reacted with the IgG of anti-t-PA. Analysis of the cell organelles using ultracentrifugation with a discontinuous sucrose density gradient revealed that the activity and the antigen of t-PA were observed near the discontinuous phase of the sucrose gradient. Analysis of 3H-mannose- and 35S-methionine-labeled t-PA in the cell organelles revealed that the radioactivity of each was increased by monensin treatment, and that such treatment increased the ratio of 3H-mannose-related glycoprotein to 35S-methionine-related protein. The sugar chain of intracellular t-PA was analyzed with endoglycosidase H and N-glycanase, which reduced the molecular weight of t-PA by 4.5-10 kDa, indicating the intracellular presence of a high-mannose type sugar chain and a complex-type sugar chain of t-PA. t-PA secreted from the monensin-treated cells possesses a high-mannose type sugar chain only. Therefore, monensin alters the secretion of t-PA by abnormal glycosylation.

Biological Transport, Active↗
PubMed1989

Synthesis of myo-inositol derivatives required for the total synthesis of surugatoxin, prosurugatoxin, and neosurugatoxin.

Two myo-inositol derivatives (4) and (5), required for the total synthesis of surugatoxin, prosurugatoxin, and neosurugatoxin, were prepared. Synthesis of (+/-)-2,3-O-cyclohexylidene-4,5-O-isopropylidene-1-O-methoxymethyl-myo-i nositol (4) was achieved from (+/-)-1-O-benzoyl-2,3-O-cyclohexylidene-4,5-O-isopropylidene-myo-inosito l (6) in 4 steps, and (-)-2,3-O-cyclohexylidene-1,4-di-O-methoxymethyl-5-O-[2',3',4'-tri-O-ace tyl- beta-D-xylopyranosyl]-myo-inositol (5) was synthesized from (+/-)-1-O-benzoyl-2,3-O-cyclohexylidene-5,6-O-isopropylidene-myo-inosito l (12) in 7 steps.

Chemical Phenomena↗
PubMed1989

Relationship between number of asbestos bodies in autopsy lung and pleural plaques on chest X-ray film.

We investigated the relationship between number of asbestos bodies and pleural plaques. Using sodium hypochrolite, we examined 400 autopsy lungs and could detect 71 cases whose asbestos bodies were significantly high. We checked pleural plaques on chest x-ray films of these 71 cases and compared the exact plaque at autopsy. By the criteria of Askergren and Szamosi, we classified these into three groups (probable, definite, definite with calcification). This classification is consistent with the pleural plaques found at autopsy. Cases whose pleural plaques were definite (thick) had many more asbestos bodies than indefinite cases. As for occupational histories, there were 23 cases who worked in Japanese Naval shipyards before and during World War II, 14 others in various shipyards, and 14 others who also had a history of asbestos exposure. These 51 patients died more than 30 years after the first asbestos exposure. Twenty had no definite asbestos exposure.

Adult↗
PubMed1989

Ectopic production of renin by ileal carcinoma.

A 54-yr-old woman with the symptoms of primary reninism, i.e. hypertension, metabolic alkalosis and elevated levels of plasma renin activity (PRA) and aldosterone, is described. She had an ileal cancer secreting active and inactive renin. The symptoms markedly improved after resection of the tumor. In the tumor active and inactive renin were proved to be present by an assay of angiotensin I formation in the presence and absence of renin antibody, and renin immunoreactivity was found immunohistochemically. The mRNA coding for the renin precursor was identified in the RNA-rich extract of the tumor by blot hybridization analysis with the human renin cDNA as a probe. The mRNA from the tumor was shown to be identical in molecular size to that from the human kidney by agarose gel electrophoresis. This is the first description of an ectopic renin-producing ileal carcinoma and the first demonstration of renin mRNA in the tumor tissue.

Carcinoma, Small Cell↗