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Biomedical subjects

A Sano

Publications and source records attributed to A Sano.

At least 181 records · Page 10Linked to original sources
PubMed1991

[Transient focal abnormalities of MRI and angiographic neuroimaging in status epilepticus: case report].

We reported transient changes in computed tomography (CT), angiography and magnetic resonance imaging (MRI) scans in a patient with status epilepticus, referred to us with a tentative diagnosis of neoplasma based on CT, MRI and angiographic findings, MRI showed increased signal intensity, and CT showed decreased left hemisphere attenuation without enhancement. Two months later, resolution of these radiological and clinical abnormalities had been attained. The transient CT and MRI changes probably represented focal cerebral edema, developing during focal status epilepticus.

Adult↗
PubMed1990

[MR imaging of mucocutaneous malignant melanoma in the head and neck].

MR imaging was performed in three patients with mucocutaneous malignant melanoma of the head and neck, and surgical specimens were investigated in MR-pathological correlation. Two of 3 cases were revealed to be melanotic melanoma; one arose in the maxillary sinus, and another in the bulbar conjunctiva. The remaining case was amelanotic melanoma originating in the nasal cavity. Two cases of melanotic melanoma showed different intensity on T1WI according to the melanin concentration; the more the melanin-producing process existed, the higher intensity in the tumor was shown. On T2WI there were also some differences in signal intensity; the case having more concentration of melanin changed lower partially in the areas where very high intensity was noted on T1WI, while another case remained unchanged. These findings are based on the inherent paramagnetic effect mostly compatible with the previous reports. On the other hand, the amelanotic melanoma was demonstrated as an intermediate intensity both on T1- and T2WI. Because of the higher incidence of hemorrhage in/around the tumor, it is an important diagnostic clue to this tumor, as in our case of amelanotic type. On reviewing the three cases, we consider that MR imaging offers a useful adjunct in the diagnosis of malignant melanoma.

Aged↗
PubMed1990

Concurrent on-line sampling of melatonin in pineal microdialysates from conscious rat and its analysis by high-performance liquid chromatography with electrochemical detection.

Dynamic changes of melatonin in microdialysates from the pineal gland of a freely moving rat were repeatedly determined by using on-line high-performance liquid chromatography with electrochemical detection. The detection limit for melatonin, ca. 5 pg, was well below that achieved with other systems. We observed a drastic increase of extracellular pineal melatonin during the transitional phase from the light period to the dark period. This application of microdialysis is a useful tool in the study of the physiological role of the mammalian pineal body.

Animals↗
PubMed1990

Further studies on D-3-aminoisobutyrate-pyruvate aminotransferase.

D-3-Aminoisobutyrate-pyruvate aminotransferase (EC 2.6.1.40, D-BAIB aminotransferase) participates in the metabolism of thymine. Recently we purified this enzyme from rat liver. We have studied D-BAIB aminotransferase further to clarify its physiological function. Among our findings were the following. (1) The enzyme activity was widely distributed in the organs of guinea pigs and rats. The kidney, liver, and lung showed high specific activities. (2) Using the livers of six vertebrates, differences between species were studied. Activity was detected in all species, the human liver showing the lowest activity among them. (3) Developmental study using rat liver showed that the activity was low at birth, increased sharply thereafter for 10 days, and then subsequently declined to the adult level. (4) Intraperitoneal injection of BAIB and beta-alanine in rats was performed to determine whether they induce activity of this aminotransferase. Only BAIB increased the activity of the aminotransferase in the liver significantly. (5) Subcellular distribution study of this aminotransferase in rat liver revealed that it is a mitochondrial enzyme.

Aging↗
PubMed1990

[CT-guided biopsy of thoracic mass lesions followed by fast stain technique].

We performed CT-guided needle biopsy of 92 thoracic mass lesions using a Rotex-II screw needle. Fast stain technique was performed for an immediate evaluation of the specimen in the last 39 procedures. The overall accuracy of malignancy was 93.2%, and the correct histological typing was obtained in 82.8% of malignancy proven at surgery or autopsy. The method enabled histopathological diagnosis of thoracic lesions, which could not obtained by other diagnostic modalities including fiberoptic bronchoscopy or fluoroscopy-guided biopsy. The true positive rate increased up 10.2% to 91.3% by introducing fast stain technique. A close cooperation between radiologists and cytopathologists was essential for performing this CT-guided biopsy procedure followed by fast stain technique.

Adenocarcinoma↗
PubMed1990

High concentration of free trimethyllysine in red blood cells.

A high concentration of a basic unidentified amino compound was found in the blood of rats. It was isolated and identified as N epsilon,N epsilon,N epsilon-trimethyllysine by paper chromatography, thin-layer chromatography, high-performance liquid chromatography and amino acid analyzer. It was localized exclusively in red blood cells in the blood of rats. Free trimethyllysine was also determined in the liver, kidney, spleen, brain, muscle, heart and testis of rat. The concentration of free trimethyllysine in red blood cells was more than 10-times as high as that in the other tissues. This compound in red blood cells was found in different species of animals. The relationship between this free trimethyllysine and carnitine was discussed.

Amino Acids↗
PubMed1990

Purification and characterization of D-3-aminoisobutyrate-pyruvate aminotransferase from rat liver.

D-3-Aminoisobutyrate-pyruvate aminotransferase (EC 2.6.1.40) was purified 1900-fold from rat liver extract. The purified enzyme showed a molecular mass of 180 kDa by gel-permeation HPLC analysis using a TSK gel G3000SW column. Reductive polyacrylamide gel electrophoresis in sodium dodecyl sulfate resulted in identification of a single band of approx. 50 kDa, indicating that the native enzyme is probably a tetrametric protein. The specific activity of the purified enzyme was 1.14 mumol/min per mg protein. D-3-Aminoisobutyrate and beta-alanine were good amino donors. The Km value for L-3-aminoisobutyrate was 100-times larger than that for the D-isomer. The apparent Km values for D-3-aminoisobutyrate and beta-alanine were 35 and 282 microM, respectively. Pyruvate, glyoxylate, oxalacetate, 2-oxo-n-valerate, and 2-oxo-n-butyrate were good amino acceptors. The apparent Km values for pyruvate and glyoxylate were 32 and 44 microM, respectively.

Animals↗
PubMed1990

Unusual trihydroxy bile acids in the urine of patients treated with chenodeoxycholate, ursodeoxycholate or rifampicin and those with cirrhosis.

Urinary bile acids from 20 patients treated with chenodeoxycholate, 18 treated with ursodeoxycholate, 15 treated with rifampicin and 8 patients with advanced cirrhosis were analyzed by gas-liquid chromatography and gas-liquid chromatography-mass spectrometry. Occurrence rates and amounts of three so-called unusual trihydroxy bile acids, hyocholate, ursocholate and omega-muricholate, were increased in patients treated with chenodeoxycholate, ursodeoxycholate or rifampicin and decreased in cirrhotic patients as compared with those in untreated healthy adults. These data suggest that chenodeoxycholate and ursodeoxycholate are hydroxylated to produce unusual trihydroxy bile acids in bile acid-loaded humans and that this metabolism may be related to the induction of hepatic microsomal enzymes by rifampicin. In contrast, the hydroxylation of chenodeoxycholate and ursodeoxycholate may be impaired by severe hepatic damage. Because the urine is a secretory pathway for internal bile acids, the occurrence of unusual trihydroxy bile acids in the urine may be used as an indicator of hepatic ability to metabolize "hydrophobic" dihydroxy bile acids to their secretory forms.

Bile Acids and Salts↗
PubMed1990

Osteoarthrosis induced by intra-articular hydrogen peroxide injection and running load.

Osteoarthrosis of the rat knee joint was induced successfully by intra-articular injection of 2% hydrogen peroxide (H2O2) and running load. In the group receiving two injections of physiological saline with running load, no histological osteoarthrotic knees were developed up to 8 weeks after the injection. In the group receiving two 2% H2O2 injections and running load, advanced osteoarthrosis occurred in all knees 8 weeks after the first injection, and the Mankin's score of osteoarthrotic knees appeared to be higher than the group receiving two 2% H2O2 injections without running load (p less than 0.004, Kruskal-Wallis H test). In the rats receiving a single 2% H2O2 injection with running load and a vitamin E-enriched diet, the inhibitory effect of vitamin E on the development of osteoarthrosis was statistically significant compared to the regular diet group (p less than 0.05, Wilcoxon rank test).

Animals↗
PubMed1990

Entrapment of left renal vein in children with orthostatic proteinuria.

We found that patients with orthostatic protein-uria had entrapment of the left renal vein (LRV) by the aorta and superior mesenteric artery (SMA). Of 15 patients studied, ultrasonographic examination showed 13 cases of typical LRV entrapment with prestenotic dilatation, and 2 cases of mild LRV compression between the aorta and SMA. Intra-arterial digital subtraction angiography and monitoring of pull-back pressure from LRV to the inferior vena cava (IVC) were performed on 2 patients with 4+ proteinuria. Accumulation of contrast medium was seen with mild back-flow to the collateral veins, and pressure gradients between LRV and IVC were 4 mmHg and 8 mmHg, respectively. Eighty school-children formed a control group and were investigated ultrasonically. Nine showed typical LRV entrapment, among whom 3 had moderate to massive orthostatic proteinuria. The discovery of LRV entrapment in patients with orthostatic proteinuria gives definite evidence of LRV congestion and may be possibly a cause of massive protein secretion from the left kidney.

Adolescent↗
PubMed1990

Uptake and processing of glycoproteins by isolated rat hepatic endothelial and Kupffer cells.

Mannose-(Man) and N-acetylglucosamine- (GlcNAc)-terminated glycoproteins are cleared from blood by carbohydrate-specific receptors present on both hepatic endothelial and Kupffer cells. It is not known whether the same receptors are present on each cell type or the relative contributions to glycoprotein metabolism made by Kupffer and endothelial cells. Here we report experiments where data from glycoprotein metabolism by purified populations of isolated rat hepatic endothelial and Kupffer cells have been analyzed by mathematical modelling and parameter estimation. Kupffer cells had significantly higher binding rate constants (k'21) than endothelial cells for agalactoorosomucoid (AGOR) and hyaluronidase, but lower k12 ('off-rate') indicating that Kupffer cells had higher affinities for Man/GlcNAc-terminated glycoproteins than endothelial receptors. Furthermore, although endothelial cells had similar affinities (k'21 and k12) for AGOR and hyaluronidase, the 'off-rate' of Kupffer cells was significantly greater for AGOR than for hyaluronidase, indicating that Kupffer cell receptors have lower affinity for AGOR. Internalization and ligand catabolic rates also differed between the two cell types. The data indicate that Kupffer and endothelial cells appear to have different Man/GlcNAc receptors and that the destination of a glycoprotein and its subsequent processing is determined by the structure of a glycoprotein's oligosaccharide.

Animals↗
PubMed1990

Calcium-associated cytoprotective effect of taurine on the calcium and oxygen paradoxes in isolated rat hepatocytes.

Our study was designed to determine the calcium and oxygen paradoxes in isolated rat hepatocytes, and to evaluate the cytoprotective effects of taurine on hepatocytes during oxygenation, hypoxia, and on these paradoxes. The calcium and oxygen paradoxes were clearly revealed in isolated rat hepatocytes. As the formation of the superoxide radical was accelerated by the hyperbaric conditions and the calcium ions, drugs such as superoxide dismutase and a calcium channel blocking agent (verapamil), prevented these paradoxes. Taurine decreased the oxygenation-induced lipid peroxidation of hepatocytes, and prevented the hypoxia-induced hepatocyte death in a calcium-containing medium, but not in a calcium-free medium. Taurine also protected the hepatocytes from injuries associated with the calcium and oxygen paradoxes due to the inhibition of sudden calcium influx into the hepatocytes.

Animals↗
PubMed1990

Stability and degradation pattern of cefpirome (HR 810) in aqueous solution.

The stability and degradation pathways of a new semi-synthetic cephalosporin, 1-[[(6R,7R)-7-[2-(2-amino-4-thiazolyl)glyoxylamido]-2-carboxy-8-ox o-5-thia-1-azabicyclo[4.2.0]oct-2-en-3-yl]methyl]-6,7-dihydro-5H-1- pyridinium hydroxide, inner salt, 7(2)-(Z)-(O-methyloxime) sulfate (cefpirome sulfate, HR 810), were studied. Cefpirome in various buffer solutions was allowed to stand at 40 degrees C and its degradation patterns were investigated by high performance liquid chromatography. Cefpirome was stable in the region of pH 4-7 and slightly unstable beyond this range. In aqueous solution from the neutral to alkaline regions, the produced degradation products were: 1- [[(6R,7S)-7-[2-(2-amino-4-thiazolyl)glyoxylamido]-2-carboxy-8-oxo -5-thia-1-azabicyclo[4.2.0]oct-2-en-3-yl]methyl]-6,7-dihydro-5 H-1- pyridinium hydroxide, inner salt, 7(2)-(Z)-(O-methyloxime) (epi-cefpirome); 1-[[(6R,7R)-7-[2-(2-amino-4-thiazolyl)glyoxylamido]-2-carboxy-8-ox o-5-thia-1-azabicyclo[4.2.0]oct-3-en-3-yl]methyl]-6,7-dihydro-5H-1- pyridinum hydroxide, inner salt, 7(2)-(Z)-(O-methyloxime) (delta 2-cefpirome); 2-[[(2-amino-4-thiazolyl)((Z)-methoxy-imino)acetyl]amino]acetaldehyde; and 6,7-dihydro-5H-1-pyrindine. On the other hand, 1-[[(6R,7R)-7-[2-(2- amino-4-thiazolyl)glyoxylamido]-2-carboxy-8-oxo-5-thia-1- azabicyclo[4.2.0]oct-2-en-3-yl]methyl]-6,7-dihydro-5H-1-pyridinium++ + hydroxide, inner salt, 7(2)-(E)-(O-methyloxime) (anti-cefpirome), 2-[[(2- amino-4-thiazolyl)-((Z)-methoxyimino)-acetyl]aminomethyl]-1,2,5,7- tetrahydro-7-oxo-4H-furo[3,4-D]-[1,3]thiazine, and 6,7-dihydro-5H-1- pyrindine were produced in strongly acidic solution or under irradiation by artificial sunlight.

Cephalosporins↗
PubMed1990

Particle design of tolbutamide by the spherical crystallization technique. III. Micromeritic properties and dissolution rate of tolbutamide spherical agglomerates prepared by the quasi-emulsion solvent diffusion method and the solvent change method.

With the objective of modifying the micromeritic properties of tolbutamide (i.e., to manufacture a highly functional powder form), particle design was attempted using a quasi-emulsion solvent diffusion (QESD) method, and the micromeritic properties and dissolution rate of the obtained spherical agglomerates were evaluated by comparison with agglomerates prepared by the solvent change (SC) method. For the production of tolbutamide agglomerates by the QESD method, a necessary condition was the addition of a sucrose fatty acid ester to the system as an emulsifying agent. The particle diameter of the agglomerates obtained by the QESD method depended on the size of the initially formed quasi-emulsion droplets, which in turn depended on the viscosity of the solution. In addition, the agglomerates were nearly perfectly spherical in shape. In the QESD method, the quasi-emulsion droplets crystallized instantaneously from the droplet surface inward. The resultant agglomerates were dense, had great mechanical strength and showed excellent flowability due to their perfect spherical shape. On the other hand, the agglomerates produced by the SC method were conglomerates of primary crystals, and fine, needle-like crystals formed on their surface. As a result, these agglomerates had a large specific surface area, and they therefore showed greater solubility than the agglomerates prepared by the QESD method.

Chemistry, Pharmaceutical↗
PubMed1990

Increased accumulation of N-isopropyl-(I-123)p-iodoamphetamine in bronchial carcinoid tumor.

Radionuclide imaging with N-isopropyl-(I-123)p-iodoamphetamine ([123I]IMP) was performed in a patient with recurrent bronchial carcinoid tumor. Increased accumulation of [123I]IMP was observed in the known lesions of the brain and neck on both tomographic and planar images. Scintigraphy also revealed unknown metastatic lesions of the paraaortic lymph nodes, which were later confirmed on x-ray CT. Iodine-123-IMP may have a potential role in evaluating carcinoid tumors.

Adult↗
PubMed1990

[MR imaging for lung cancer in evaluating local invasion; referring to CT and surgical-histological basis].

The diagnostic potentiality of MR imaging for lung cancer was researched in 17 patients in evaluating local invasions based on surgical-histological evidence. Comparative reviewing with CT was also performed. MR imaging appeared to have an ability unique to portray malignant invasions somewhere such as in the hili or apices. On the other hand, there were also some diagnostic limitations of MR imaging in delineating the localized invasive changes. On the way of working up lung cancer, CT still may stand at the first choice as a radiographic staging procedure which provides the more detailed anatomic-pathologic informations. We consider that MR imaging is mandatory when CT and/or other modalities could'not obtain efficient results.

Adenocarcinoma↗