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Biomedical subjects

Y Takashima

Publications and source records attributed to Y Takashima.

At least 73 records · Page 4Linked to original sources
PubMed1995

Assessment of MRI criteria for MS in Japanese MS and HAM/TSP.

We evaluated the usefulness of the MRI criteria for multiple sclerosis (MS) proposed by Paty et al and Fazekas et al in 36 Japanese MS patients, using HTLV-I-associated myelopathy (HAM)/tropical spastic paraparesis (TSP) as the control. Although 30 of 36 HAM/TSP patients had multiple white matter lesions on T2-weighted cranial MRI, only two fulfilled the MRI criteria for MS. At the same time, 31 of the 36 MS patients fulfilled the primary MRI criterion, yielding 93% specificity and 86% sensitivity for the criterion. MS has disease-specific MRI abnormalities.

Brain↗
PubMed1994

Oxidation-induced aggregation of rabbit low-density lipoprotein by azo initiator.

Oxidation of low-density lipoprotein (LDL) has been considered as an important step in the early pathogenesis of atherosclerosis. We investigated the oxidative modification of LDL by a water-soluble azo-initiator AAPH (2,2,-azo-bis(2-amidinopropane).2HCl) and analyzed the uptake of AAPH-oxidized LDL with mouse peritoneal macrophages. Oxidative modification of LDL by AAPH was similar to the modification induced by copper in regard to the degree of oxidation and formation of aggregated LDL. The aggregated oxidized (AO-) LDL was fractionated by gel permeation chromatography and compared with the monomeric oxidized (MO-) LDL to make clear their characterization. The results of binding, cell association, and degradation with macrophages indicated that both AO- and MO-LDL were bound and endocytosed by macrophages. The cross competition experiment showed that nonreciprocal competition existed among MO-LDL, AO-LDL, and monomeric acetylated (MAc-) LDL. By the sterol accumulation experiment in macrophages with the various types of modified LDL, the cellular sterol accumulation was shown as the following order, AO-LDL > MAc-LDL > MO-LDL. These results indicated that the oxidation by AAPH can induce the aggregation of LDL and that the AO-LDL contribute to lipid accumulation into macrophages more than the MO-LDL.

Acetylation↗
PubMed1994

Ultrastructure of the ootype of the lung fluke Paragonimus ohirai (Digenea, Troglotrematidae) in mated and single-infection worms.

The ootype of Paragonimus ohirai was studied by both scanning and transmission electron microscopy. The ootype wall in 20-week-old worms from single infections was similar in its epithelial cell architecture and components to that of mated worms at 10 weeks postinfection. The lining epithelium consisted of a single layer of nucleated cells. The cytoplasm displayed a variety of organelles such as occasional Golgi complexes, well-developed annulate lamellae, frequent lysosomes, abundant mitochondria, and numerous ribosomes, suggesting high activities of intracellular synthesis and digestion. The former three organelles were generally located in the apical cytoplasm protruding into the lumen and may be significant in participating in regulation of egg formation. The present comparative studies suggest that the ootype epithelium can mature even by single infections and that the organized intracellular activities remain developed in single worms even after prolonged infection.

Animals↗
PubMed1994

Application of calcium silicate for medicinal preparation. I. Solid preparation adsorbing an oily medicine to calcium silicate.

Calcium silicate (Florite RE, FLR), a fine porous powder, was recently approved as a medicinal additive. In this study we sought to make a solid preparation by absorbing an oily medicine to FLR; tocopheryl nicotinate (TN) was used as the oily medicine. TN adsorbed to FLR powder (TN-PO) was prepared by adsorbing TN ethanol solution to FLR and granulating with hydroxypropylcellulose (HPC) in order to improve the flowability. The results were as follows. FLR showed an excellent liquid holding ability compared with other excipients, and this was attributed to the high capillarity of the pores. In the adsorbing process, FLR particles were granulated with TN overflowing from the pores or adhering to the particle surface. The angle of repose was decreased with increasing TN content, which was attributed to the process of granulation, and the angle of repose of the granules with a binder (TN-GR) was below 40 degrees at any TN content. These results show that FLR is an useful additive for the solid preparation of an oily medicine.

Adsorption↗
PubMed1994

Characterization of aggregated low density lipoproteins induced by copper-catalyzed oxidation.

Oxidation of low density lipoproteins (LDL) has been shown to lead to enhanced uptake by macrophages mediated by the scavenger receptor. In the present study, changes in LDL induced by copper-catalyzed oxidation were investigated using gel permeation chromatography (GPC), and the results were compared with several parameters of oxidized LDL (ox-LDL). When LDL at 200 micrograms/ml was oxidized with 10 microM Cu2+ at 37 degrees C for up to 24 hours, increases in thiobarbituric acid-reactive substances and electrophoretic mobility were first observed within 3 hours. An increase in fluorescence and a decrease in intact apolipoprotein B (apoB) were than observed in parallel with an increase in 125I-LDL degradation by macrophages after 6 hours. Finally, LDL aggregation separated by liquid chromatography was observed after 24 hours. The aggregated and monomeric fractions of ox-LDL were analyzed and the results compared with the monomeric fraction of native LDL. Both fractions of ox-LDL contained hardly any intact apoB and showed an intense fluorescence. The electrophoretic mobility increment of aggregated ox-LDL was almost half that of monomeric ox-LDL, yet the lysine residues of aggregated ox-LDL were more extensively decreased than those of monomeric ox-LDL. Degradation of aggregated ox-LDL by macrophages showed a slightly greater increase than that of monomeric ox-LDL. GPC analysis is a useful method to estimate the LDL aggregation, and these results provide a basis to investigate the formation of aggregated LDL.

Animals↗
PubMed1994

Localization of peroxidase activity in tegumental, muscle, and parenchymal cells of the lung fluke Paragonimus miyazakii (Digenea: Troglotrematidae).

The distribution and localization of peroxidase activity were examined in adults of Paragonimus miyazakii in sections stained with 3,3'-diaminobenzidine in the presence of hydrogen peroxide. Peroxidase activity was detected in tegumental cell mitochondria. With cell development, the reaction intensity became greater. Activity extended from the inner membrane (undifferentiated stage) to the intermembrane space (differentiating stage) and then to the matrix (differentiated stage). Mitochondria with the most intense reaction were densely distributed in the outer syncytial region. Strong activity was also present in mitochondria of muscle cells and in those of Type II parenchymal cells. Intermembrane spaces were the predominant site of this activity. Characteristically, both 10 mM azide and 1 mM cyanide were mildly effective in the inhibition of mitochondrial peroxidase activity in each cell type.

3,3'-Diaminobenzidine↗
PubMed1993

Nematolysosomes (elongate lysosomes) in rat hepatocytes: their distribution, microtubule dependence, and role in endocytic transport pathway.

The distribution of lysosomes in rat hepatocytes was examined by three-dimensional electron microscopy combined with acid phosphatase (ACPase) cytochemistry. In the 2-microns-thick sections observed under 200- or 1000-kV TEM, it was apparent that ACPase activity localized on elongate lysosomes (we refer to them as nematolysosomes) with a diameter of 70-100 nm and lengths of several micrometers, as well as spherical lysosomes and trans-Golgi cisternae. Though most spherical lysosomes were located within the pericanalicular region, nematolysosomes were widely distributed throughout the hepatocytes. Typically, it appeared that the nematolysosomes elongated from the subsinusoidal region to the pericanalicular-Golgi complex area and they frequently formed a network at the cell periphery along the sinusoidal front. Furthermore, the formation of nematolysosomes was independent of new protein synthesis, but highly dependent on the integrity of microtubules. After a 6-8 h colchicine treatment, nematolysosomes were shrunk and/or fragmented, becoming roughly spherical lysosomes scattered throughout the cells. Nematolysosomes recovered their normal profiles after 24 h due to the reversible effect of the drug on microtubules. When the hepatocytes were exposed to horseradish peroxidase (HRP) in vitro or in vivo, HRP was quickly sequestered in nematolysosome-like structures via pinocytosis from the sinusoidal surface and transported to an area near the Golgi complex. These findings raise the possibility that the nematolysosomes engage in microtubule-dependent transport of macromolecules from the sinusoidal circulation to the Golgi complex area.

Acid Phosphatase↗
PubMed1993

The shape and distribution of lysosomes and endocytosis in the ciliary epithelial cells of rats.

The shape and distribution of lysosomes in the ciliary epithelium of rat eyes were examined by electron microscopy combined with acid phosphatase (ACPase) cytochemistry and three-dimensional observation of 2 microns-thick sections. ACPase activity was cytochemically localized in lysosomes and trans Golgi cisternae in the non-pigmented epithelial (NPE) and pigmented epithelial (PE) cells. In NPE cells, it was shown three-dimensionally, that most lysosomes had an elongate form, up to 5 microns in length, and a diameter of 70-100 nm. These elongate lysosomes (nematolysosomes) were predominantly located in the basal region of the cells. In contrast, PE cells had spherical lysosomes distributed at random throughout the cytoplasm. However, no nematolysosomes were seen in the PE cells. When the isolated ciliary processes were incubated in a medium containing horseradish peroxidase (HRP), HRP was incorporated into the nematolysosome-like structures by pinocytosis from the basal surface of the NPE cells. These findings suggest that nematolysosomes are associated with the pinocytotic activity of NPE cells. The pinocytosis-nematolysosomal route may be involved in the uptake and degradation of macromolecules from the aqueous humor in the posterior chamber.

Acid Phosphatase↗
PubMed1993

Serial bronchoalveolar lavage studies in a patient with intra-alveolar fibrosis following Legionnaires' disease.

A 48-year-old male developed acute respiratory failure owing to Legionnaires' disease (LD). Antibiotic treatment including erythromycin and rifampicin was not effective, thus transbronchial lung biopsy was performed. The histological examination of the lung showed intra-alveolar fibrosis. Corticosteroid therapy was begun and he responded well with definite clinical improvement. Bronchoalveolar lavage (BAL) was performed three times in the following year. The first BAL showed an increase of lymphocytes which then decreased significantly in the following studies. This case report thus demonstrates the importance of lung biopsy of protracted LD and the usefulness of BAL in the assessment of corticosteroid therapy.

Bronchoalveolar Lavage Fluid↗
PubMed1993

[Serum and pleural SCC-antigen levels in patients with pulmonary tuberculosis].

We measured the serum and pleural levels of squamous cell carcinoma related antigen (SCC-Ag) in patients with active pulmonary tuberculosis and studied the relationship between SCC-Ag and tuberculosis. Serum levels of SCC-Ag in 63 patients with newly diagnosed untreated tuberculosis were 1.76 +/- 2.16 ng/ml, significantly higher than in 118 healthy controls (0.67 +/- 0.52 ng/ml) or in 11 patients with old tuberculosis (0.92 +/- 0.38 ng/ml; p < 0.01). Pleural effusion levels of SCC-Ag in 41 patients with tuberculosis pleurisy were 4.5 +/- 3.4 ng/ml, significantly higher than in 54 patients with non-malignant, non-tuberculous, pleurisy (2.3 +/- 1.7 ng/ml: p < 0.05). In patients who responded well to anti-tuberculous chemotherapy, serum levels of SCC-Ag decreased to the normal range (1.6 ng/ml) with clinical improvement, while in nonresponders they did not decrease. Isoelectolic focusing electrophoresis showed serum SCC-Ag to be composed of a neutral fraction as a single peak, which was corresponded to that of squamous cell carcinoma of the lung. The tuberculous lesions were stained with anti-SCC-Ag antibody in one case and weak SCC-Ag positive findings were observed in the intercellular spaces of the epidermoid cells in the area without necrosis. These results raise the possibility that SCC-Ag is produced in or released from not only squamous cell carcinoma of the lung but also pulmonary tuberculous lesions.

Adult↗
PubMed1993

[New criteria for evaluating the findings of clinical laboratory tests. New reference values for ascertaining biological effects of various environmental factors].

In this article new reference values and methodology of clinical laboratory tests useful as guidelines for providing health instruction on health effects of various environmental factors are suggested. Two different processes are developed as the methods for determining the reference values, which are comprised of three elements. One of the processes is based solely on the analysis of the relationship between a certain environmental factor and the result of a certain laboratory test (Unifactor method). The other process includes also analysis of other confounding factors in addition to analysis by the unifactor method (Multifactor method). Basic to these statistical analyses is the comparison of distribution of pertinent data among individuals with and without the factor. Using one of the reference values, 'X1 (unifactor method) or x1 (multifactor method)', we can discriminate those individuals who will be affected by an environmental factor with the highest reliability. Another reference value, 'X2 (unifactor method) or x2 (multifactor method)', on the other hand, can be used to identify those individuals in whose case the health effect of the factor must be closely considered. In some cases, a third reference value, 'X0 (unifactor method) or x0 (multifactor method), can also be determined. This value corresponds to the lowest or highest limit of the range that would not be associated with the factor. We believe that many health promotion activities may become more effective through the utilization of the results of health examinations that include assessment of total and environmental factors.

Clinical Laboratory Techniques↗
PubMed1993

An improved technique for observing both membranous organelles and cytoskeleton in saponin-extracted cells.

Detergent-extraction of soluble cytoplasmic proteins under low osmotic pressure induces severe morphological damage, particularly on membranous organelles, although this processing is often required to observe cytoskeletal elements in the cells. In the present study, the osmotic adjustment of the rinsing solution and fixative, which were used after the detergent-extraction using saponin, has greatly improved the ultrastructure of membranous organelles. This improved method allowed us to observe both cytoskeletal elements and the fine structure of membranous organelles by electron microscopy.

Animals↗
PubMed1992

Genetic analysis of a Japanese family with normotriglyceridemic abetalipoproteinemia indicates a lack of linkage to the apolipoprotein B gene.

Normotriglyceridemic abetalipoproteinemia is a rare familial disorder characterized by an isolated deficiency of apoB-100. We have previously reported a patient with this disease, who had normal apoB-48 but no apoB-100. To elucidate the genetic abnormalities in this family, we studied the linkage of apoB gene using three genetic markers. The proband and her affected brother showed completely different apoB gene alleles, suggesting that the apoB gene itself is not related to this disorder in this family. By contrast, an American case had a point substitution in the apoB gene generating an in-frame stop codon. These results indicate that this disorder can be caused by defect(s) of either an apoB gene or other genes.

Abetalipoproteinemia↗
PubMed1992

Study on the environmental behavior of Chernobyl-derived radionuclides in Kyushu Island, Japan.

The environmental behavior of Chernobyl-derived radionuclides in Kyushu Island was investigated for one month after the accident. The radioactivity level in airborne dusts was two orders of magnitude lower than that observed in Western Europe. The distribution of 131I in airborne dusts shifted to a larger particle size compared with other radionuclides. The radionuclide concentration in seaweeds varied depending on the geographical situation where the sampling was done. The biological half-lives in red algae were calculated to be 17.4 d and 32.9 d for 131I and 103Ru, respectively. The concentration factors in red algae were estimated to be 3 x 10(3) and 5 x 10(3) for 131I and 103Ru, respectively. The cooking effect of 131I in seaweeds and the committed effective dose equivalent through ingestion of seaweed were also evaluated.

Accidents↗
PubMed1992

Possible enhancing effect of the immunosuppressive agent, 6-mercaptopurine(6-MP) on focal lesion development in cirrhotic liver induced by carbon tetrachloride but not furfural in F344 rats.

The modifying effects of an immunosuppressive agent, 6-mercaptopurine (6-MP), on development of focal lesions in liver cirrhosis models induced by carbon tetrachloride (CCl4) or furfural were studied in male F344 rats. Feeding of 6-MP at 50 p.p.m. for 20 weeks to animals with pre-existing liver cirrhosis caused immunosuppression, and significantly enhanced the induction of gamma-glutamyltranspeptidase (GGT)-positive foci and nodules in the CCl4 but not furfural case. Glutathione S-transferase P (GST-P)-positive preneoplastic lesions were not affected. Moreover, phenobarbital (PB) also enhanced the induction of GGT-positive hepatocellular lesions only in the CCl4-induced liver cirrhosis model, no promotion influence being exerted after treatment with the non-carcinogenic furfural. This study, therefore, suggests that 6-MP can enhance the induction of one type of preneoplastic foci and nodules and that essential differences exist between focal lesions arising in cirrhotic livers caused by CCl4 as opposed to furfural.

Alkaline Phosphatase↗