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Biomedical subjects

H Hoshi

Publications and source records attributed to H Hoshi.

At least 325 records · Page 18Linked to original sources
PubMed1985

Production of an auto-stimulatory growth factor by human hepatoma cells abrogates requirement for a brain-derived factor.

Human hepatoma cells grow at high cell density in the absence of exogenous growth factors. At low cell density, two different hepatoma cell lines required a novel growth factor from brain tissue. A factor with similar physico-chemical properties in the concentrated medium from high density cultures completely substituted for the brain extract. The autogenous secretion of a novel liver cell growth factor that is concentrated in brain tissue may underlie in part the unregulated growth of hepatomas.

Brain-Derived Neurotrophic Factor↗
PubMed1985

Influence of diabetes on arteriosclerosis.

The cholesterol contents of the posterior cerebral, subclavian, left common carotid, coronary, superior mesenteric and renal arteries were determined in 6 nondiabetic and 21 diabetic autopsy subjects. The dry weight of the arteries per length was 1.40 to 2.96 times greater in the diabetic group than in the nondiabetic group. The contents of cholesterol in the arteries of the diabetic group were also 1.07 to 4.10 times greater than those of the nondiabetic group. Statistically significant correlation was demonstrated between the dry weight of the arteries per length in the nondiabetic group and the contents of cholesterol in the arteries of the nondiabetic group and the diabetic group. Relation between the cholesterol content (x) in the artery of nondiabetic group and ratio (y) of the cholesterol content in the artery of the diabetic group to the nondiabetic group could be expressed by the following regression equation; y = 4.303 - 0.558 x (r = -0.843, p less than 0.002). Most of correlation coefficients between dry weight of each artery, or between the cholesterol content of each artery were low. These results suggest that arteriosclerosis is enhanced in the diabetics, especially in smaller artery where the cholesterol content is low, and arteriosclerosis in the diabetics develops not uniformly.

Aged↗
PubMed1985

Histological observations on rat popliteal lymph nodes after blockage of their afferent lymphatics.

Afferent lymphatic vessels to the popliteal lymph node in the rat were blocked, and the node was histologically examined 2-35 weeks later. After the operation, the node was reduced in size and its lymphoid structures, such as germinal centers, lymph follicles and deep cortex units, were decreased in size and number. At 16 weeks, the lymphoid organization of the node reached a minimal level, but the node still exhibited reduced numbers of lymphoid structures. The lymphoid parenchyma of the node, although reduced in size, showed no noticeable change in cellular density during the period of observation. The changes observed in the popliteal node following blockage of the afferent lymphatics were interpreted as resulting from a reduced supply via the afferent lymph of antigens and other factors on which the development and persistence of the lymph node structures are believed to depend.

Animals↗
PubMed1984

Brain- and liver cell-derived factors are required for growth of human endothelial cells in serum-free culture.

A test of the mitogenic activity of greater than 40 purified and crude sources of hormones and growth factors revealed that epidermal growth factor, high density lipoprotein, an extract of bovine pituitary, hypothalamus, or whole brain, and the medium conditioned by differentiated human hepatoma cells were mitogenic for cultured endothelial cells derived from human umbilical vein. The four active agents combined with an improved nutrient medium and a collagen- or fibronectin-coated culture surface supported the growth of the endothelial cell population at a rate of 0.70-0.80 generations per day at both low and high cell densities in serum-free medium. The brain-derived activity exhibited properties reported by Maciag et al. [Maciag, T., Hoover, A. & Weinstein, R. (1982) J. Biol. Chem. 257, 5333-5336] and Gordon et al. [Gordon, P. B., Sussman, I. I. & Hatcher, V. B. (1983) In Vitro 19, 661-671]. The liver cell-derived activity was a specific product of differentiated hepatoma cells. The medium from HeLa cells, relatively undifferentiated rat liver cell lines, and human fibroblasts was inactive. Purified plasma proteins of liver origin could not substitute for the hepatoma cell-conditioned medium. The hepatoma cell-derived activity was non-dialyzable, heat-labile, stable between pH 4 to 11, inactivated by trypsin and mercaptoethanol treatment, and stable after treatment with 6 M urea and phenylmethylsulfonyl fluoride. The results provide a simplified model for elucidation of the endocrinology of human endothelial cell growth, function, and aging. We suggest an endocrine role of both the nervous system and liver in the regeneration of endothelial cells.

Animals↗
PubMed1984

Reconstruction of lymph follicles in the mouse popliteal lymph node after X-irradiation damage.

In order to suppress possible "de novo" formation of follicles in the node after irradiation, animals to be irradiated received surgical operations to block the afferent lymphatics to the popliteal node on one side, the corresponding node on the other side left intact. 600 R whole body X-irradiation severely destroyed lymph follicles in the nodes of both sides, but the number of follicles in the node on either side recovered toward normal by 3 weeks after irradiation, regardless of whether they contained germinal centers or not. In animals exposed to 1,000 R whole body X-irradiation and infused with bone marrow cells, no lymph follicles were observed in the nodes on day 9. If such treated animals were given 1.0 X 10(8) lymph node cells on day 5, lymph follicles were reconstructed in the nodes of both sides on day 9. In animals irradiated with 1,000 R to the lower half of the body, the number of follicles in the node on either side remained comparable to that of the unirradiated control node. The results favor the interpretation that although X-irradiation destroys the lymphoid elements of the follicles, the stromata of follicles persist and preserve the ability to collect small lymphocytes, and that lymph follicles are reconstructed at the sites of the stromata persisting from damaged follicles.

Animals↗
PubMed1984

Uptake of carbon and polystyrene particles by the sinusoidal endothelium of rabbit bone marrow and liver and rat bone marrow, with special reference to multiparticle-pinocytosis.

The endocytosis of tracer particles by sinusoidal endothelial cells was studied in the bone marrow and liver of the rabbit and in the bone marrow of the rat after intravenous injection. The tracer particles used included carbon particles and polystyrene particles of different sizes ranging from 0.11 to 5.7 micron in diameter. The sinusoidal endothelial cells of the rabbit liver and rat bone marrow took up carbon through the formation of bristle-coated vesicles at the luminal surface, but they eventually failed to ingest polystyrene particles of 0.11 micron or larger. On the other hand, the sinusoidal endothelial cells of the rabbit bone marrow took up carbon and polystyrene particles varying from 0.11 to 2.02 micron in diameter. These endothelial cells were found to sequester circulating tracer particles in the cytoplasm through the formation of two kinds of vesicles at the luminal surface: bristle-coated vesicles and "multiparticle-pinocytotic vesicles." This special type of pinocytotic vesicle was larger in diameter than the bristle-coated vesicle and variable in size according to the size or amount of the particles to be sequestered. Carbon and 0.11 micron polystyrene particles were taken up by means of both the bristle-coated vesicles and multiparticle-pinocytotic vesicles, whereas particles 0.30 micron in diameter or larger were taken up by the vesicles similar in nature to multiparticle-pinocytotic vesicles. A sequence for the morphological events occurring in the formation of multiparticle-pinocytotic vesicles in the sinusoidal endothelial cells of rabbit bone marrow shall be suggested and discussed.

Animals↗
PubMed1984

Formation of lymph follicles and germinal centers in draining lymph nodes after local injection of phytohemagglutinin and lipopolysaccharide in mice.

Changes in the number of lymph follicles and germinal centers in draining popliteal lymph nodes were investigated in 8-week-old mice injected with either phytohemagglutinin (PHA) or lipopolysaccharide (LPS) into the footpad of the left hind leg. The dose of PHA injected ranged from 10 micrograms to 1 mg, and that of LPS, from 2 to 200 micrograms. In unstimulated animals, the popliteal lymph nodes contained only a small number of germinal centers, and many of the lymph follicles in the nodes were in the form of primary follicles. In the draining lymph nodes, regardless of the dose injected, PHA induced germinal center development in existing primary follicles, but eventually failed to stimulate the formation of new lymph follicles and germinal centers. On the other hand, LPS not only induced germinal centers in the existing follicles, but also stimulated the formation of new primary follicles, many of which then developed germinal centers. The occurrence of new follicles in the LPS-treated lymph nodes was dose-dependent, and LPS appeared to cause de novo formation of follicles.

Animals↗
PubMed1984

[Measurement of the liver and spleen volume by single photon emission computed tomography].

Organ volume was experimentally and clinically determined using single photon emission computed tomography (SPECT). In organ phantom filling with 99mTcO4-, the error was less than 3.3% in the volume over 400 ml but 11% at 200 ml. In 28 cases of patient, liver and spleen volume were measured by SPECT and X-CT. Good correlation was founded between SPECT volume and X-CT volume (r = 0.99, n = 49), although SPECT volume were 16% higher than X-CT volume (y = 1.16 x + 11.6, x: X-CT volume, y: SPECT volume).

Adult↗