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Biomedical subjects

Y Okabe

Publications and source records attributed to Y Okabe.

At least 19 recordsLinked to original sources
PubMed1992

The association of hypopituitarism with small pituitary, invisible pituitary stalk, type 1 Arnold-Chiari malformation, and syringomyelia in seven patients born in breech position: a further proof of birth injury theory on the pathogenesis of "idiopathic hypopituitarism".

We report seven cases of hypopituitarism all having a history of breech delivery, asphyxia at birth, and syringomyelia. A small pituitary gland was found on MRI or CT in six cases, invisible pituitary stalk on MRI in five cases, and type 1 Arnold-Chiari malformation in six cases. A constellation of these abnormalities are best explained by traction of brain and spinal cord of the subjects exerted during breech delivery and further support the primary role of birth trauma in the genesis of "idiopathic hypopituitarism".

Adolescent↗
PubMed1992

Anorexia induced by toxohormone-L isolated from ascites fluid of patients with hepatoma.

To ascertain anorexigenic effect of toxohormone-L, a polypeptide extracted and purified from ascites of patients with hepatoma were infused into the rat third cerebroventricle. Food intake decreased on the first day after infusion of an optimum dose of 10.0 micrograms (p less than 0.05). The suppressive effect on feeding was linearly dose dependent (p less than 0.05). Meal size and latency to the first meal decreased in the 12-h dark period, and the first and the second 4-h cumulative blocks after infusion of a 10.0 micrograms dose (p less than 0.01 for each). The suppressive effects on total food intake and meal size were completely recovered within 24 h after infusion. Neither postprandial intermeal interval nor eating speed was affected. Periprandial drinking, a ratio of water intake to food intake, was not affected after infusion of 5.0 and 10.0 micrograms toxohormone-L. Infusion of a 10.0 micrograms dose showed no effect on ambulation. These findings suggest that anorexia and cachexia produced in cancer patients may essentially be due to the suppressive effect of toxohormone-L on food intake.

Animals↗
PubMed1992

Intratemporal facial nerve neurinoma without facial paralysis.

A 38-year-old man was referred by his general practitioner to our department on 28 October 1991, with a 2-week history of vertigo. A left aural polyp was identified. The audiogram showed a moderate conductive loss on the left side. Computed tomography (CT) and magnetic resonance imaging (MRI) confirmed the presence of the expanding lesion in the descending portion of the facial nerve. However, there was no seventh nerve paresis. At operation, the neurinoma (Schwannoma) filled the middle ear cleft and extended from the genu to the stylomastoid foramen. The floor of the middle ear had been eroded, exposing the jugular bulb. Facial nerve paresis is the usual presenting feature of a facial neurinoma. The case is presented for the reason that the absence of facial palsy as a presenting feature is rather rare, especially in the cases with large tumor and extensive bone erosion.

Adult↗
PubMed1992

Growth retardation in childhood leukemia and lymphoma. Special reference to patients with CNS relapse.

We studied the growth of 89 patients who were long-term survivors of childhood leukemia and lymphoma. Eight patients with CNS relapse had a greater decrease in height standard deviation score (SDS) after the relapse than 81 patients without CNS relapse (p less than 0.0001). Two patients who received cranial irradiation when they were younger than 2 years of age demonstrated a marked decrease in height SDS more than 3.0 SD. Five patients appeared to have a decline in height SDS before their CNS relapse. There were no apparent changes in the weight of patients with or without CNS relapse. In endocrine studies, all eight patients with CNS relapse failed to show the normal growth hormone (GH) response to arginine, GH-releasing factor, and glucagon-propranolol tests, while spontaneous GH secretion during sleep was normal. Magnetic resonance imaging (MRI) revealed small pituitary glands in seven patients with CNS relapse. These findings suggest that in leukemia and lymphoma patients with CNS relapse, GH secretion is impaired at the hypothalamic level, resulting in a secondary atrophy of the pituitary gland. The MRI together with selected endocrinologic tests may help to clarify the mechanism of growth impairment in such patients. A decline in height SDS in each patient may be a useful marker for predicting a CNS relapse in a child with leukemia or lymphoma.

Adolescent↗
PubMed1992

Small hepatocellular carcinoma: diagnosis with US angiography with intraarterial CO2 microbubbles.

Ultrasonographic (US) angiography enhanced with intraarterial CO2 microbubbles, a contrast material used in US imaging, was performed of 103 histologically proved hepatocellular carcinomas (HCCs) smaller than 3 cm in diameter in 95 patients. The detection rate for hypervascular HCC with US angiography was compared with the rate of detection with conventional angiography, digital subtraction angiography (DSA), and computed tomography (CT) after intraarterial injection of iodized oil. Sensitivity in detection of hypervascular HCCs with US angiography was 86% (89 of 103 HCCs), compared with 63% (44 of 70 HCCs) detected with conventional angiography, 70% (23 of 33 HCCs) with DSA, and 82% (75 of 91 HCCs) with CT with iodized oil. US angiography depicted small hypervascular HCCs, especially those less than 1 cm in diameter, and helped clarify vascularity as isovascular or hypovascular in angiographically undetectable HCCs. Findings at US angiography assisted the choice of a therapeutic strategy for treatment of HCC, such as transarterial therapy, percutaneous ethanol injection therapy, or resection.

Angiography, Digital Subtraction↗
PubMed1992

Argyrophilic proteins of the nucleolar organizer region in acute leukemias and its relation to the S-phase fraction of leukemic cells.

Nucleolar organizer regions (NORs) are loops of DNA which transcribes to ribosomal RNA. The NOR-related protein becomes visible in nucleus by a silver-staining technique under a light microscope, and it has been named argyrophilic protein of NOR (Ag-NOR). In various malignancies, the correlation between the proliferation potential of tumor cells or histological grade and the number of Ag-NORs has been reported. In this study, we investigated the Ag-NOR of acute leukemic cells and its relation to the in vivo proportion of bone marrow leukemic cells in DNA synthetic phase. The number of Ag-NORs in bone marrow leukemic cells was more than that in peripheral blood (means values 2.78 and 2.48, respectively, p less than 0.01). This result shows that the number of Ag-NORs reflects the vigorous proliferative potential of bone marrow leukemic cells. However, no significant correlation was obtained between the number of Ag-NORs and the bromodeoxyuridine-labeling indices (r = 0.2064). These results suggest that Ag-NOR might be one of the markers for cellular proliferation in leukemia, while DNA synthesis of leukemic cells do not seem to be directly related to Ag-NOR. In order to clarify the role of Ag-NOR in leukemia, further studies are needed.

Adolescent↗
PubMed1992

Sonography with intraarterial infusion of carbon dioxide microbubbles (sonographic angiography): value in differential diagnosis of hepatic tumors.

Differential diagnosis of small liver tumors is important, but is not always possible, even with angiography. To solve this problem, we introduced sonographic angiography, which combines sonography and angiography. The vascular pattern of a variety of hepatic nodules was evaluated with sonographic angiography, and the results were compared with those of conventional angiography. Sonographic angiography (sonography performed during intraarterial infusion of carbon dioxide microbubbles) was performed in 184 patients with a total of 222 hepatic nodules: 139 hepatocellular carcinomas, nine adenomatous hyperplasias, seven regenerative nodules, 21 hemangiomas, 33 metastases, seven lymphomas, one granuloma, and five focal nodular hyperplasias. Sonographic angiography detected a hypervascular pattern with peripheral blood supply in cases of hepatocellular carcinoma (sensitivity, 90%; specificity, 89%). Typical vascular patterns of adenomatous hyperplasia, hemangioma, metastasis, and focal nodular hyperplasia on sonographic angiography were hypovascularity (sensitivity, 100%; specificity, 91%), spotty pooling (sensitivity, 100%; specificity, 100%), peripheral hypervascularity (sensitivity, 64%; specificity, 100%), respectively. The detectability of hypervascularity was greater with sonographic angiography than with conventional angiography in hepatocellular carcinoma, metastasis, and hemangioma. Our experience indicates that sonographic angiography depicts characteristic vascular features that reflect the vascular anatomy of specific types of hepatic tumors, and thus is useful in the differential diagnosis of these lesions.

Carbon Dioxide↗
PubMed1992

Multiple hemangiopericytomas of the spleen.

Splenic tumors are uncommon. Described is a 58-yr-old man with multiple hemangiopericytomas of the spleen. Hemangiopericytoma is categorized as a benign vascular tumor, but has a relatively high malignant potential. A review of the literature shows that the case we present is only the second ever reported of a tumor originating from the spleen. Radiological findings and the treatment of the tumor are discussed.

Hemangiopericytoma↗
PubMed1992

[Clinical utility of receptor imaging in the assessment of liver function].

Technetium-99m diethylene triamine pentaacetic acid-galactosyl human serum albumin (TcGSA) is a newly developed receptor-binding radiopharmaceutical, specific for the asialoglycoprotein receptor, which resides exclusively on the plasma membrane of hepatocytes. Clinical utility of TcGSA was evaluated in 3 control subjects with normal livers and in 54 patients with various liver diseases. The parameter, Receptor Index, was derived from liver and heart time-activity data and is the ratio of radioactivity of the liver over the radioactivity of the liver plus heart at 15 min after the intravenous injection of 3 mg of TcGSA. Receptor concentration ([R]o) was obtained by kinetic analysis of liver and heart time-activity data using pharmacokinetic nonlinear modeling. Values for the Receptor Index and [R]o was statistically different in the control subjects and in patients with mild, moderate, and severe liver diseases. Good correlations were obtained between the Receptor Index, [R]o and conventional liver function tests, such as Child-Turcotte criteria score, prothrombin time, and indocyanine green test. Receptor Index and [R]o were properly estimated even in patients with obstructive jaundice or remarkable portocaval shunt. These data suggest that the receptor imaging as well as its parameters, Receptor Index and [R]o, is a potentially practical and reliable diagnostic method for estimating the functioning hepatocyte mass and for assessing liver function.

Adult↗
PubMed1992

[Hepatic receptor imaging with Tc-99m GSA: estimates of liver function in acute liver disease].

Technetium-99m galactosyl human serum albumin (TcGSA) is a synthesized radiolabeled analog ligand to asialoglycoprotein receptor, which resides only at a mammalian hepatocyte. TcGSA studies were performed on 16 patients with various acute liver disease and 3 controls with normal livers. Dynamic data were obtained by a gamma camera during 35 minutes after an intravenous injection of 3 mg (185 MBq) of TcGSA. The parameters of TcGSA time activity curves were obtained by dividing radioactivity of the liver by that of the liver plus heart at 15 min (Receptor Index), and by dividing radioactivity of the liver at 15 min by that at 3 min post injection (Clearance Index). The two parameters correlated well with prothrombin time, clinically estimated staging, and severity of acute liver disease. We have concluded that liver function study by the newly developed receptor imaging with TcGSA can be a sensitive and promising tool in estimating the severity and prognosis of acute liver disease.

Acute Disease↗
PubMed1991

A novel mechanism of cation/substrate cotransport: Na+/H+/adenosine cotransport in Vibrio parahaemolyticus.

Adenosine is actively transported with Na+ in Vibrio parahaemolyticus (Sakai, Y., Tsuda, M., Tsuchiya, T. (1987) Biochim, Biophys. Acta 893, 43-48). The proton conductor carbonylcyanide m-chlorophenylhydrazone, CCCP, strongly inhibited active transport of adenosine at pH 8.5 as well as at pH 7.0. This seemed peculiar because the driving force, an electrochemical potential of Na+, is established by the Na(+)-extruding respiratory chain at pH 8.5 in this organism, although it is established by the function of the Na+/H+ antiporter at pH 7.0. This suggested that H+ might be involved in the adenosine transport. We detected H+ uptake induced by adenosine influx in V. parahaemolyticus cells in the presence of Na+, but not in its absence, suggesting the occurrence of Na+/H+/adenosine cotransport. We isolated formycin A-resistant mutants which showed defective adenosine transport. The mutation resulted in simultaneous losses of Na+ uptake and H+ uptake induced by adenosine. In revertants from these mutants the Na+ uptake and H+ uptake were restored simultaneously. The frequencies of reversion were in the order of 10(-7), indicating that the mutations were single mutations; namely that Na+/adenosine cotransport and H+/adenosine cotransport took place via the same carrier. Thus, we conclude that adenosine is transported by the novel mechanism of Na+/H+/adenosine cotransport in V. parahaemolyticus.

Adenosine↗
PubMed1991

Comparative base specificity, stability, and lectin activity of two lectins from eggs of Rana catesbeiana and R. japonica and liver ribonuclease from R. catesbeiana.

Two lectins with RNase activity obtained from eggs of Rana catesbeiana and R. japonica and RNase obtained from R. catesbeiana liver show 65-83% protein homology. The base specificity of these frog proteins was studied with 8 dinucleoside phosphates as substrates and 8 nucleotides as inhibitors. The base specificities of the B1 and B2 sites of these proteins are U greater than C and G greater than U greater than A, C, respectively. The three frog proteins are more resistant than RNase A to heat treatment, guanidine-HCl and pH-induced denaturation; i.e., they retain their native conformation up to at least 70 degrees C at pH 7.5. Differences in stability and base specificity among RNase A and the three frog proteins are discussed in relation to the primary structures. Although the two lectins agglutinate tumor cells (e.g., Ehrlich, S-180 and AH109A ascites carcinoma cells), the liver RNase has no such activity. Agglutination of AH109A cells by the two lectins is inhibited by nucleotides. Our results indicate that the agglutination sites are not identical with, but are related to, the active sites of the three frog proteins.

Amino Acid Sequence↗
PubMed1991

Application of bromodeoxyuridine (BrdU) and anti-BrdU monoclonal antibody for the in vivo analysis of proliferative characteristics of human leukemia cells in bone marrows.

To investigate the proliferative characteristics of human bone marrow leukemic cells in vivo, we developed a new method using bromodeoxyuridine (BrdU) and its monoclonal antibody. Thirty minutes after a bolus BrdU infusion, a lst bone marrow aspiration (BMP) was performed to calculate the BrdU labeling index (BrdU-LI). Then, a 150-min continuous infusion of BrdU was started. Immediately after the infusion, a 2nd BMP was done to analyze the increasing rate of the BrdU-LI for 3 h. Each smear was stained by an immunohistochemical method. The BrdU-LI, the duration of S phase (Ts) and the cell cycle time (Tc) of leukemic cells from 13 previously untreated patients with acute leukemias were estimated. A mean value of 7.2% for BrdU-LI was obtained. Furthermore, mean values of 9.7 h and 152.5 h for Ts and Tc respectively were calculated. This method may prove to be useful in the in vivo cell cycle analysis of leukemias and other malignancies.

Antibodies, Monoclonal↗
PubMed1991

Intramuscular hemangioma of the masseter muscle: its characteristic appearance on magnetic resonance imaging.

A 10-year-old girl presented with a 6-month history of right facial swelling. Magnetic resonance imaging (MRI) revealed a tumor in the masseter muscle. On exploration through a preauricular incision, a vascular mass was found located in the lateral aspect of the right masseter muscle. The characteristic MRI appearance of the intramuscular hemangioma of the masseter muscle is shown and the value of MRI for a preoperative differential diagnosis is discussed.

Child↗