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Biomedical subjects

H Yoshioka

Publications and source records attributed to H Yoshioka.

At least 19 recordsLinked to original sources
PubMed1992

[MR imaging of thyroid masses].

Magnetic resonance (MR) imaging was performed in 35 patients with histologically proved thyroid masses. Gadopentetate dimeglumine was used in 25 of these cases. The thyroid tumors were analyzed by MR imaging as to shape, margin, pseudocapsulation, homogeneity, and enhanced pattern. Gd-DTPA was helpful in identifying pseudocapsules and showing the extent of the tumor. Papillary carcinoma tended to display unclear margins, heterogeneous intensity, and inhomogeneously enhanced patterns. In follicular adenoma, the tumor margin was smooth and pseudocapsules were clearly detected. Follicular adenoma was enhanced homogeneously, but it was difficult to distinguish follicular adenoma from follicular carcinoma by MR imaging. Adenomatous goiter was delineated as multiple nodules with smooth margins, but without pseudocapsules. These nodules were enhanced in various ways after Gd-DTPA administration.

Female↗
PubMed1992

[Evaluation of US contrast medium (LEVOVIST) to experimental liver cancer].

Enhancement of liver cancer on ultrasonography (US) by injection of new contrast medium (LEVOVIST) was performed in rats with 3'-methyl-4-dimethylaminoazobenzene-induced hepatic carcinoma. Echosignals of cancer nodules increased remarkably after the intrahepatic arterial injection of LEVOVIST (200, 300 mg/ml), and contrast enhancement was observed for at least 15 minutes. Furthermore, US after the intrahepatic arterial injection of LEVOVIST (200 mg/ml) can visualize small nodule, which was not recognizable on plain US. As a result of increased echosignals of normal liver parenchyma after the intra-portal injection of LEVOVIST (300 mg/ml), the cancer nodules were demonstrated as hypoechoic. These results indicate that this new contrast medium for sonography is effective in the diagnosis of liver cancer.

Animals↗
PubMed1992

[Electron-microscopic study on the effect of an expandable metallic stent placement in the aortic wall].

As part of a series of basic experiments on using metallic stents for treatment of vascular stenosis, a chronological examination of changes in dog aorta following implantation of a self-expandable metallic stent was conducting using transmission and scanning electron microscopy. The Giantruco stent was placed in the abdominal aorta via the right carotid artery. One week after insertion, the aortic intima was depressed and degenerative changes observed in both endothelial and medial smooth muscle cells. After 2 weeks, except for the bend portion, the stent was covered with neointima. The neointimal surface was covered by premature endothelial cells with abundant microvilli and prominent nuclear protrusions. Under the endothelial cells, immature mesenchymal cells, such as fibroblast, were scattered throughout the edematous intercellular space. At 4 weeks, the stent was completely covered by neointima and the endothelial cells had flattened and few microvilli were in evidence. In this thickened intima, premature smooth muscle cells with myofilaments and basement membranes were observed but, around them, few collagen fibers and only occasional elastic fibers were found. At 6 weeks, the intimal surfaces were flat and smooth with a slight intimal elevation over the stent. No thrombus was observed throughout the period of the experiment. The above results indicate that dilation using metallic stents may be a useful method for treatment of vascular stenosis.

Animals↗
PubMed1992

[Direct injection chemotherapy combined with arterial embolization in the treatment of liver cancers].

Direct injection chemotherapy in combination with transcatheter arterial embolization (TAE) was carried out in primary and secondary liver cancers. In this treatment, the anticancer agents dissolved in contrast media were directly injected into the tumor tissue with the echo-guided puncture needle after TAE. The dynamics of the injected drugs marked with non-ionic and water-soluble contrast media was followed up by the sequential CT studies, on which the contrast media was observed only in the tumor area in 18 out of 30 nodules from 2 to 8 weeks after the injection. The procedure is considered an effective drug delivery system to achieve a targeting chemotherapy in the liver cancers.

Antineoplastic Agents↗
PubMed1992

Immunohistochemical demonstration of a new thiamine diphosphate-binding protein in the rat digestive tract.

We purified a new thiamine diphosphate-binding protein (ThDP-BP), produced an antiserum against it, and examined its immunohistochemical distribution in the rat gastrointestinal tract using the avidin-biotin complex method. Positive staining for ThDP-BP was found in the epithelial glands of the stomach, small intestine and large intestine, and in the nuclei of hepatocytes. Measurement of the content of thiamine and its phosphate esters in extracts from the gastric and intestinal mucosa also indicated the presence of ThDP-BP in the stomach and intestinal mucosa. ThDP-BP may be useful for investigating the absorption and metabolism of the thiamine in metabolic disorders.

Animals↗
PubMed1992

Effectiveness of Lipiodol in transcatheter arterial embolization of hepatocellular carcinoma.

The effectiveness of Lipiodol (iodized oil) in transcatheter arterial embolization (TAE) of hepatocellular carcinoma (HCC) was retrospectively evaluated using statistical analysis. A total of 343 HCC patients who underwent TAE at 5 institutions between 1984 and 1989 were divided into 2 groups: the GS-TAE group underwent TAE with Gelfoam sponge alone, whereas the LP-TAE group was given Lipiodol (LP) immediately before GS-TAE. The statistical T value calculated for the LP-TAE group showed that the administration of LP, the tumor size, intrahepatic metastasis, portal vein infiltration, and serum total bilirubin and alpha-fetoprotein levels significantly (P < 0.01) affected the patients' survival. Both the cumulative survival determined using the Kaplan-Meier model and the cumulative hazard calculated using Cox's proportional hazard model differed significantly (P < 0.01) between the GS-TAE group and the LP-TAE group (log-rank test). These results confirmed the effectiveness of LP used in combination with Gelfoam sponge for TAE of HCC.

Aged↗
PubMed1992

Cytochrome b positive X-linked chronic granulomatous disease: a normal cell surface expression of cytochrome b.

The polymorphonuclear (PMN) cells from a patient with cytochrome b positive X-linked chronic granulomatous disease (Xb+ CGD) were studied using flow cytometry. Both the cell surface expression of monoclonal antibody defined cytochrome b and the superoxide production (intracellular 2',7'-Dichlorofluorescin Diacetate oxidation) were investigated at a single cell level. Flow cytometry clearly demonstrated the complete absence of superoxide production in the patient's PMN cells, the mosaicism in his mother's PMN cells and also indicated the normal cell surface expression of cytochrome b. The results obtained by Western blot analysis and reduced-minus-oxidized spectra confirmed the presence of functional and normal amounts of cytochrome b. We concluded that this is a case of Xb+ CGD with a normal cell surface expression of cytochrome b.

Adolescent↗
PubMed1992

Clinical trials of intrasplenic arterial infusion of interleukin-2 (IS-IL-2) to patients with advanced cancer.

We tried a infusion of interleukin-2 (IL-2) of a relatively low dose via an intrasplenic arterial catheter connected to a chronometric infusion (IS-IL-2). Eighteen patients of colorectal cancer with metastases to the liver or lung or of unresectable hepatoma received a 24 hour continuous infusion with low dose recombinant of IL-2 (mainly 8 x 10(5) JRU/day) for 25-40 days. All patients tolerated this protocol of the therapy and the main toxic effects were fever and general fatigue. Such serious toxicity as previously reported by high dose IL-2 therapy was not observed. Data of hepatic and renal functions were normal. IS-IL-2 therapy induced a high incidence of eosinophilia (12/18) and thrombocythemia (12/18). Peripheral natural killer (NK) and LAK activities were augmented in all patients and total white blood cell counts were increased during IS-IL-2 therapy. An increase in IL-2 receptor expression of peripheral blood mononuclear cells and significant rises in numbers of Leu11 (CD16)+, OKM1(CD11)+ and OKIa1(HLA-DR)+ were observed. Of 18 patients 12 were evaluable for their response to therapy. Partial response (PR) was observed in one unresectable hepatoma and 11 demonstrated no change (NC) or progressive disease (PD). Six patients were not evaluable because of additional therapy (3 cases) or decreasing tumor cell markers having no measurable lesions (3 cases). Three patients of colorectal cancer from an unresectable group were presumed to have micrometastases to the liver as suggested by an elevated serum CEA level. After receiving IS-IL-2 therapy they demonstrated a decrease in the serum CEA level for more than 3 years after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Synteny between the loci for a novel FACIT-like collagen locus (D6S228E) and alpha 1 (IX) collagen (COL9A1) on 6q12-q14 in humans.

A 1.8-kb cDNA encoding portion of a novel collagenous chain was isolated from a human rhabdomyosarcoma cell line by cross-hybridization using a chicken type V collagen probe. Sequence analysis suggests that this chain belongs to the recently discovered group of collagens, termed the FACIT class of macromolecules. This cDNA was used to locate the corresponding gene (D6S228E) to chromosome 6, notably at position 6q12-q14. Interestingly, within this region of human chromosome 6 residues the alpha 1 (IX) collagen gene (COL9A1), a member of the FACIT group.

Amino Acid Sequence↗
PubMed1992

13C-nuclear magnetic resonance of glycosphingolipids.

Spectra of 125 MHz 13C-nuclear magnetic resonance (NMR) of glycosphingolipids, GlcCer, GalCer, sulfatide, LacCer, and nLc4Cer have been studied, and the following results were obtained. (i) Signals of ring carbons of each sugar component are distributed in a wide field (50-110 ppm) and clearly separated. (ii) Chemical shifts of anomeric carbon (C1) and methylene carbon (C6) of sugars are far from those of other methine carbons of sugars and characteristic of sugar components, which makes it possible to identify each sugar component and its molar raito. (iii) The downfield shifts (about 6-9 ppm) of alpha-carbon signals involved in the glycosidic linkages and upfield shifts (about 1.5-2 ppm) of the neighboring beta-carbons, which are known as glycosylation shifts, could be observed. (iv) Characteristic shifts of aglycon signals caused by the presence of an OH group at the alpha-position of fatty acid were assigned. These observations are useful for the characterization of glycosphingolipid structures.

Carbohydrate Conformation↗
PubMed1992

Effects of neonatal asphyxia on the serotonin neuron system in the developing brain studied by immunohistochemistry.

The effects of neonatal asphyxia on the serotonin neuron system were examined using the immunoperoxidase method. Male mice, 2 days of age, were exposed to total asphyxia (100% CO2) for 30 min. Mice that spontaneously survived were perfused transcardially with a fixative at 15, 30 and 60 days of age. Quantitative immunohistochemical analysis at 60 days of age demonstrated a significant decrease in the numbers of serotonin-immunoreactive cell bodies in the nucleus raphe dorsalis, the nucleus raphe pontis, the subpyramidal region, the total raphe system and the whole brain, while no significant reduction in the number of serotonin-immunoreactive cell bodies was observed in the caudal raphe system. Presumably degenerative changes in serotonin-immunoreactive fibers were observed in various parts of the brain of mice subjected to total asphyxia at 15 days of age, and the numbers of degenerated fibers decreased in almost all parts of the brain, the exception being the caudal portion of the brainstem, at 30 and 60 days of age. These results suggested that neonatal asphyxia induced permanent changes in the serotonin neuron system, with regional differences.

Animals↗
PubMed1992

Pharmacokinetics of high-dose methylprednisolone in children.

Disposition of methylprednisolone was characterized in 11 children receiving the high-dose therapy (26.0 mg/kg on average). After intravenous infusion, methylprednisolone hemisuccinate was rapidly converted to methylprednisolone with a half-life of about 20 min. Methylprednisolone in serum, eliminated monoexponentially in 8 patients and biexponentially in the remaining three, had the mean residence time of about 3 h, and a terminal half-life of 2.5 h. The volume of distribution at steady state, and the clearance were 1.3 liters/kg and 0.5 liters/kg/h, respectively. Although these average pharmacokinetic parameters were comparable to those determined in other studies with conventional low doses, the clearance values in our data were characterized by 5-fold interindividual difference, suggesting large variations in exposures to methylprednisolone among children on the high-dose pulse therapy.

Adolescent↗
PubMed1992

Gluteal compartment syndrome. A report of 4 cases.

Four cases of gluteal compartment syndrome are presented, 1 traumatic and 3 after an overdose of sedatives. Associated lesions included sciatic nerve palsy in 2 cases and acute renal failure in 1. Three cases with intramuscular pressure exceeding 60 mmHg underwent emergency fasciotomy. Intramuscular pressure monitoring is useful for evaluating the effect of fasciotomy.

Adult↗
PubMed1992

P-31 MR spectrum and histologic changes after intrahepatic arterial injection of iodized oil in normal and cirrhotic rat liver.

Injection of iodized oil (Lipiodol) into the hepatic artery is widely used in the diagnosis and treatment of hepatocellular carcinoma. However, no reports have yet appeared concerning temporal changes in hepatic metabolism following Lipiodol injection. In the present study, Lipiodol was injected into the hepatic arteries of normal and cirrhotic rats, successive P-31 MR measurements were performed, and temporal changes in metabolism were compared with histologic findings. Both normal and cirrhotic rats displayed minimum levels of beta-ATP/PME and beta-ATP/Pi 5 days after hepatic arterial injection of Lipiodol. However, 10 days after injection these values had reverted to the preinjection levels. The metabolic dysfunction observed in the liver following hepatic arterial injection of 0.3 ml/kg b.w. Lipiodol was transient. Moreover, no distinct differences were observed between P-31 MR changes in normal and cirrhotic rats. Conversely, histologic impairment assessed on the basis of hepatic necrosis ratios was most severe 2 days after hepatic arterial injection in both normal and cirrhotic rats, and this did not coincide with the time of the most pronounced metabolic impairment as inferred from P-31 MR changes.

Animals↗
PubMed1992

Immunohistochemical localization of basal lamina components in the developing rat epiphyseal cartilage canals.

The purpose of this study was to investigate the relationship between the appearance of basal lamina components (Type IV collagen and laminin) and the development of cartilage canals. In the distal femoral epiphyses from developing rats, the distribution of basal lamina components in the cartilage canal was examined immunohistochemically. The formation of cartilage canals from the perichondrium was first observed on the fifth day after birth. By Day 8, a few cartilage canals penetrated the epiphyseal cartilage and considerably increased in size and length. By light microscopic immunohistochemistry, reticular structures stained with anti-Type IV collagen and antilaminin antibodies were observed in the cartilage canals. In the early development of cartilage canals, however, immunostaining by anti-Type IV collagen antibodies was weaker than that by antilaminin antibodies. In eight-day-old rats, the laminin-positive reticular structures were more densely colored and more widely distributed in the canal than the Type IV collagen-positive ones. Type IV collagen was found around the endothelial cells of the developing capillaries by electron microscopic immunohistochemistry. Laminin was observed in the cytoplasm of the mesenchymal fibroblastic cells and their pericellular matrix as well as in the capillary basal lamina. These immunohistochemical electron microscopic observations can explain the differences that are observed in Type IV collagen and laminin immunostaining patterns as cartilage canals develop. Laminin synthesized by the mesenchymal fibroblastic cells may promote the migration and the outgrowth of endothelial cells in the formation of cartilage canals.

Animals↗