669 research outputs found
Primary culture of adult rat liver cells. I. Preparation of isolated cells from trypsin-perfused liver of adult rat
Isolated hepatic cells from adult rats were prepared by perfusing the livers with trypsin. The highest yield of viable cells was obtained by perfusing the liver with 0.1% trypsin, pH 7.0, at 37 degrees C for 30 min. Following this treatment about 70% of cells excluded trypan blue. The isolated cells contained many binucleate cells. Between 60 and 70% of DNA present originally in the liver was recovered from the isolated hepatic cells, which had higher glucose 6-phosphatase activity than the liver. Thus the resulting cell population seems to be rich in hepatocytes. The isolated hepatic cells, however, lost some of their cellular proteins such as alanine and tyrosine amino-transferases. It was suggested that the membranes of isolated hepatic cells might be damaged by both enzymatic digestion and mechanical destruction.</p
Halo-Galaxy Lensing: A Full Sky Approach
The halo-galaxy lensing correlation function or the average tangential shear
profile over sampled halos is a very powerful means of measuring the halo
masses, the mass profile, and the halo-mass correlation function of very large
separations in the linear regime. We reformulate the halo-galaxy lensing
correlation in harmonic space. We find that, counter-intuitively, errors in the
conventionally used flat-sky approximation remain at a % level even at very
small angles. The errors increase at larger angles and for lensing halos at
lower redshifts: the effect is at a few % level at the baryonic acoustic
oscillation scales for lensing halos of , and comparable with the
effect of primordial non-Gaussianity with at large
separations. Our results allow to readily estimate/correct for the full-sky
effect on a high-precision measurement of the average shear profile available
from upcoming wide-area lensing surveys.Comment: 12 pages, 4 figure
Primary culture of adult rat liver cells. II. Cytological and biochemical properties of primary cultured cells.
Primary mass culture of isolated cells from adult rat livers by the trypsin-perfusion method uas carried out to investigate cytological and biochemical properties of primary cultured cells. Two main types of cells were found in the course of primary culture of isolated hepatic cells. One was a group of polygonal cells with granular cytoplasm, which appeared to arrange themselves in cords and clusters 3 to 4 days postinoculation and then gradually decreased in number. These cells seemed to be associated with expression of liver specific functions such as higher tyrosine aminotransferase levels and transient increases in albumin production. Another type of cells was relatively small in size and had clear cytoplasm, which grew out rapidly in place of the polygonal cells and proliferated also in subculture. alpha-Fetoprotein was detected in the cultured media of the proliferating clear cells. These results suggest that the polygonal cells and the clear cells may correspond to the mature hepatocytes and the hepatocytic stem cells in vivo, respectively.</p
Cross-correlating the Thermal Sunyaev-Zel'dovich Effect and the Distribution of Galaxy Clusters
We present the analytical formulas, derived based on the halo model, to
compute the cross-correlation between the thermal Sunyaev-Zel'dovich (SZ)
effect and the distribution of galaxy clusters. By binning the clusters
according to their redshifts and masses, this cross-correlation, the so-called
stacked SZ signal, reveals the average SZ profile around the clusters. The
stacked SZ signal is obtainable from a joint analysis of an
arcminute-resolution cosmic microwave background (CMB) experiment and an
overlapping optical survey, which allows for detection of the SZ signals for
clusters whose masses are below the individual cluster detection threshold. We
derive the error covariance matrix for measuring the stacked SZ signal, and
then forecast for its detection from ongoing and forthcoming combined
CMB-optical surveys. We find that, over a wide range of mass and redshift, the
stacked SZ signal can be detected with a significant signal to noise ratio
(total S/N \gsim 10), whose value peaks for the clusters with intermediate
masses and redshifts. Our calculation also shows that the stacking method
allows for probing the clusters' SZ profiles over a wide range of scales, even
out to projected radii as large as the virial radius, thereby providing a
promising way to study gas physics at the outskirts of galaxy clusters.Comment: 11 pages, 6 figures, 3 tables, minor revisions reflect PRD published
versio
Decreased albumin secretion in serum-free primary cultures of adult rat hepatocytes during proliferation induced by epidermal growth factor and insulin.
Upon addition of epidermal growth factor (EGF, 0.1 microgram/ml) and insulin (0.1 microM), adult rat hepatocytes proliferated and increased 120-134% in number in serum-free primary culture. However, in the absence of the growth factors, hepatocytes decreased in number with time. The average albumin secretion per cell was much lower in the proliferating cultures than in the non-proliferating cultures. The results suggest that albumin production in hepatocytes decreases during cell proliferation.</p
Effects of antioxidants on survival of adult rat hepatocytes under various oxygen tensions in serum-free primary culture.
Effects of antioxidants, such as superoxide dismutase, vitamin C, vitamin E, 4-(0-benzylphenoxy)-N-methylbutylamine hydrochloride (bifemelane), and selenite on survival of adult rat hepatocytes were examined under normoxic and hyperoxic conditions in serum-free primary culture. The tested antioxidants, except for vitamin C, significantly increased the survival rate of hepatocytes under the normoxic condition (under air). Thus, even the normoxic culture condition is hyperoxic for hepatocytes. Elevation of oxygen tension (40% O2) caused severe morphologic degeneration of hepatocytes and remarkable decrease in the survival rate of the cells. Addition of the antioxidants effectively protected hepatocytes from the morphologic degeneration, and significantly improved the survival of the cells under the hyperoxic condition. These findings indicate that the antioxidants can maintain the long-term survival of hepatocytes in serum-free primary culture.</p
Effect of anti-alpha-fetoprotein serum on growth and plating efficiency of alpha-fetoprotein-producing hepatoma cells in vitro
The effect of a specific rabbit antiserum to rat alpha-fetoprotein (AFP) was examined on the growth and the plating efficiency of AFP-producing rat hepatoma cells (AH70Btc Clone 10-5) in cultures. The addition of anti-AFP serum to the culture medium inhibited cell growth moderately and inhibited plating efficiency markedly, although no inhibitory effect of complexes of AFP and antibody to AFP was observed on cell growth. Anti-AFP globulin in the immune serum was demonstrated on the cell surface by fluorescent antibody technique. Several clones producing low levels of AFP were obtained by long-term treatment of the original Clone 10-5 cells with anti-AFP serum. These treated clones showed characteristics that differed from the untreated original clone 10-5 cells: The relative plating efficiency of the treated clones on agar plates containing 5% anti-AFP serum was higher than the original Clone 10-15 cells and the amount of AFP secreted by the treated clones was lower.</p
Mediatory Summary Generation: Summary-Passage Extraction for Information Credibility on the Web
PACLIC 23 / City University of Hong Kong / 3-5 December 200
Transformation of primary cultured and co-cultured adult rat liver cells by 3'-methyl-4-dimethylaminoazobenzene.
Under various conditions of culture and carcinogen treatment, the transformation of liver cells by 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) was studied. Primary liver cell (PLC) cultures from adult male rats and co-cultures with PLCs of ARL-D8 cells of a liver epithelial-like clear cell line from adult female rats were treated with 0.24 mM 3'-Me-DAB for 6 days. Four of 8 carcinogen-treated PLC cultures contained cells with marker chromosomes, and 3 of the 8 cultures contained gamma-glutamyltranspeptidase (GGT)-positive cells. Three of 5 carcinogen-treated co-cultures contained cells with marker chromosomes, and 2 of the 5 co-cultures contained GGT-positive cells. Pure cultures of ARL-D8 cells were treated for 6 or 12 days with 3'-Me-DAB (0.24 mM)-containing-medium perfused through the liver of adult male rats in situ. In the 6-day treatment, none of 5 carcinogen-treated cultures showed chromosomal abnormality or cytochemically exhibited GGT activity. However, in the 12-day treatment, 2 of the 5 carcinogen-treated cultures contained cells with marker chromosomes, and 2 of the 5 cultures contained GGT-positive cells. None of the control cultures exhibited chromosomal abnormality or GGT-positive cells. In summary, transformation markers increased in ARL-D8 cells when they were co-cultured with PLCs.</p
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