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Biomedical subjects

K Shibuya

Publications and source records attributed to K Shibuya.

259 records · Page 15Linked to original sources
PubMedDate not supplied

Suppressive effect of beta-carotene on the development of pulmonary foam cells in rats with hyper beta-lipoproteinemia.

The effect of beta-carotene (BC) on the development of pulmonary foam cells (PFCs) was studied in rats with diet-induced hyper beta-lipoproteinemia. Rats were fed a standard diet; a hyper-beta-lipoproteinemia diet (HB) consisting of the standard diet, 4% cholesterol, and 1% cholic acid; or the standard diet plus 0.1% BC; or the HB diet plus 0.1% BC diet (HBC). Rats in the HB and HBC groups developed hyper-beta-lipoproteinemia, but no significant differences were observed in serum levels of total cholesterol, phospholipid, and beta- lipoprotein (B-LP) between both groups. The percentages of foamy, lipid-ingested monocytes (FMs) to the number of blood monocytes (BMs), the number and size of lipid droplets in FMs, the percentages of PFCs to the number of alveolar macrophages from bronchopulmonary lavage fluid, and the score of PFC development in the lungs of rats in the HBC group were reduced compared to those of rats in the HB group. There were no differences in latex-phagocytotic activity of BMs among rats in the control, HB, BC, and HBC groups. BC suppressed the foamy transformation of BMs and development of PFCs deriving from the influx of FMs into the alveoli of hyper-beta-lipoproteinemic rats. Based on the present results, it is presumed that the antioxidative property of BC may prevent an oxidative modification of B-LP under the hyper-beta-lipoproteinemic condition, leading to a decrease in the uptake of oxidatively modified B-LP by BMs.

Animals↗
PubMedDate not supplied

Olfactory undifferentiated carcinoma with endocranial extension in a Fischer-344 rat.

A spontaneous tumor in the nasal cavity, extending through the cribriform plate to the cranial cavity, was detected in a 103-wk-old female Fischer-344/DuCrj rat. The tumor appeared to arise from the olfactory epithelium and was composed of round to polygonal, undifferentiated cells arranged in solid sheet-like and lobular patterns with scant fibrovascular stroma. Ultrastructurally, the tumor cells often formed desmosomes between contiguous cells and had no neurosecretory granules. Immunohistochemically, the tumor cells did not react with any antibodies specific for intermediate filaments, neuronal, muscular, and endothelial elements. Based on these results, the tumor was diagnosed as undifferentiated olfactory epithelial carcinoma.

Animals↗
PubMedDate not supplied

Carbon tetrachloride-induced hepatotoxicity enhances the development of pulmonary foam cells in rats fed a cholesterol-cholic acid diet.

The effect of CCl4-hepatotoxicity on the development of pulmonary foam cells (PFCs) was studied using 4 groups of rats. Rats in the control group were fed a standard diet; rats in the second group were fed a hyper beta-lipoproteinemic (HB) diet consisting of the standard diet, 4% cholesterol, and 1% cholic acid; rats in the third group were fed the standard diet and administered with CCl4 (1.0 ml/kg, i.p., fortnightly) (CT); and rats in the fourth group were fed the HB diet and administered with CCl4 (HT). At feeding week 10, rats in the HB and HT groups developed hyper beta-lipoproteinemia. The ratios of foamy, lipid-ingested monocytes (FMs) to blood monocytes (BMs) and the histologic scores of PFC development were significantly greater in the HB and HT groups than in the control and CT groups, respectively. The ratio of PFCs to alveolar macrophages from bronchopulmonary lavage fluid was significantly higher in the HT group than in the CT group. At feeding week 20, rats in the CT and HT groups suffered hepatic injury and hypo beta-lipoproteinemia. Despite hypo beta-lipoproteinemia, the FM and PFC development, the ratio of BMs in differential leukocyte counts, and latex-phagocytotic activity of BMs were enhanced in the HT group. Furthermore, markedly enlarged FMs, described here as giant-FMs, that contained numerous lipid droplets in their abundant cytoplasm appeared in the peripheral blood from rats in the HT group. Histologically, embolism caused by giant-FMs in the pulmonary blood vessels and intraalveolar accumulation of PFCs were detected with a high incidence in the HT group. The present study suggests that CCl4-hepatotoxicity may affect lipoprotein synthesis in the liver of hyper beta-lipoproteinemic rats and defective or modified lipoproteins can be phagocytosed actively by BMs, and then BMs transform into FMs or giant-FMs, resulting in the PFC development and pulmonary embolism by giant-FMs.

Animals↗
PubMedDate not supplied

Cytomorphologic features characteristic of tumor stages of thymomas.

The cytologic findings of the tumor cells characteristic of the stages of thymomas were investigated to assess the invasiveness of the tumors. Forty-six patients with thymoma who underwent extensive thymectomy without pre-operative corticosteroid therapy were included in this study. The histologic subtypes included 18 round/oval, 20 mixed, and 8 spindle type. The stages of thymoma classified according to Masaoka's clinicopathological classification included 16 stage I, 20 stage II, 6 stage III, 2 stage IVa, and 2 stage IVb, and myasthenia gravis was recognized in 5 patients. Cytologic findings were retrospectively analyzed in the Papanicolaou-stained stamp smears obtained from the cut surfaces of thymoma specimens. Morphometry of the epithelial tumor cells using Cosmozone-1A was performed to evaluate the validity of our cytologic categories. Compared with the cytologic findings of stage I or II thymomas, those of epithelial tumor cells in stage III or IV more frequently showed necrotic background (50.0%-stage III or IV vs 11.1%-stage I or II, p=0.006), large clusters of epithelial tumor cells (70.0% vs 36.1%, p=0.055), marked nuclear enlargement (90.0% vs 52.7%, p=0.033), marked anisokaryosis (100% vs 52.7%, p=0.006), marked nuclear polymorphism (40.0% vs 5.5%, p=0.004), hyperchromasia (50.0% vs 11.4%, p=0.007) and prominent nucleoli (50.0% vs 16.6%, p=0.028) whereas no significant correlation was observed between cytologic findings and tumor volume. Morphometric studies of thymoma tumor cells revealed that the nuclear size (mean values, 78.8 microm(3)-stage III or IV vs 58.2 microm(3)-stage I or II), the coefficient of variation of the nuclear size (0.326 vs 0.282), and the nuclear rotundity (0.849 vs 0.858) differed significantly between the two categories (p<0.05). Our findings demonstrated that there were significant differences between the cytologic findings of epithelial tumor cells of stage I or II thymomas and those of stage III or IV thymomas, and that the cytologic findings of thymoma tumor cells appear to be useful for distinguishing between non-invasive and invasive thymomas.

Adolescent↗
PubMedDate not supplied

Influence of extracellular ion concentration on the intracellular accumulation of adriamycin.

The cytotoxic action of adriamycin is influenced by its intracellular accumulation. Therefore, it is important to clarify the mechanisms of adriamycin influx and efflux. In the present study, the influence of the extracellular KCl and Ca2+ concentration, the extracellular pH and the presence of NaHC03 on the ADR accumulation was investigated in order to study the mechanisms in ADR accumulation influenced by ions. The extracellular KCl concentration did not affect the intracellular ADR accumulation. This suggests the cell membrane potential does not affect the ADR accumulation since it is influenced by the KCl concentration. The intracellular intensity of fluorescence of Fluo3, an indicator of Ca2+, increased between 0 and 20 mM of the extracellular concentration of Ca2+ ion. However, the ADR accumulation did not change between 0 and 20 mM of the extracellular concentration of Ca2+. This indicates that the extracellular concentration of Ca2+ does not affect the ADR accumulation under physiological conditions since 20 mM of Ca2+ is beyond normal physiological conditions. Further, the intracellular fluorescence of Fluo3 decreased as increasing the extracellular pH. In contrast, the ADR accumulation increased as increasing the extracellular pH. These suggest that the ADR accumulation increases as decreasing the intracellular Ca2+ as changing the extracellular pH. In wild type strain, the ADR accumulation did not change by the extracellular pH in the absence of NaHCO3, but increased as increasing the extracellular pH in the presence of NaHCO3. This suggests that the ADR accumulation in the wild type strain is influenced by NaHCO3 but the extracellular pH. In the ADR-resistant strain, the ADR accumulation decreased as increasing the extracellular pH regardless of NaHCO3. However, the accumulation of ADR increased as increasing the extracellular pH when the adjustment of pH was carried out with 1N HCl. This suggests that Cl- may play an important role in the ADR influx in the ADR-resistant strain.

Aniline Compounds↗
PubMedDate not supplied

Influence of cepharanthin and hyperthermia on the intracellular accumulation of adriamycin and Fluo3, an indicator of Ca2+.

In the present study, the mechanism involved in the enhancement of adriamycin (ADR) accumulation by cepharanthin (CEP) and hyperthermia were examined. The accumulation of ADR and Fluo3 (an indicator of Ca2+) was increased by treatment with CEP. This suggests that ADR accumulation may increase due to increased influx of Ca2+. The ADR accumulation increased with increasing the KCl concentration in the presence of CEP when the KCl concentration was over 200 mM. This demonstrates that ADR accumulation increases with treatment with CEP and increasing the KCl concentration after the cell membrane potential reaches 0. ADR accumulation did not change with the extracellular pH in the absence of NaHCO3. CEP increased the ADR accumulation with increasing extracellular pH, regardless of NaHCO3. This suggests that CEP may affect the H+ flux, and consequently increase ADR accumulation regardless of NaHCO3. Further, it increased with increasing extracellular pH in the presence of NaHCO3, regardless of CEP. It is thought that the interaction between H+ and HCO3- may cause increased ADR accumulation. ADR accumulation was decreased by DIDS and amiloride at 37 degrees C. ADR accumulation in the presence of amiloride at 45 degrees C was increased compared with that at 37 degrees C. However, the accumulation combined with amiloride and hyperthermia was lower than with treatment with ADR only at 37 degrees C. This indicates that ADR accumulation is decreased by amiloride and increased by hyperthermia. ADR accumulation is further decreased by DIDS at 45 degrees C compared with 37 degrees C. This suggests that the H+ flux in hyperthermia is influenced by Cl-/HCO3- exchanger but not Na+/H+ exchanger.

Alkaloids↗