Manganese dipyridoxal diphosphate-enhanced magnetic resonance imaging in the evaluation of hepatocyte function.

Rationale And Objectives: To determine whether contrast-enhanced magnetic resonance imaging can detect ethanol hepatotoxicity in rats.

Methods: Rats were treated with a single high dose of ethanol (acute) intraperitoneally or with a 36% ethanol diet (chronic) for up to 5.5 months.

A model system for studying membrane biogenesis. Overexpression of cytochrome b5 in yeast results in marked proliferation of the intracellular membrane.

Cytochrome b5 is an amphipathic microsomal protein that is anchored to the endoplasmic reticulum by a single hydrophobic transmembrane alpha-helix located near the carboxyl terminus of the protein. In yeast, cytochrome b5 provides electrons for fatty acid desaturation and ergosterol biosynthesis. High level expression of cytochrome b5 in Saccharomyces cerevisiae was achieved using the yeast metallothionein promoter and a synthetic cytochrome b5 gene.

Structure, distribution and composition of the extracellular matrix of human oocytes and cumulus masses.

The structure, distribution and composition of the extracellular matrix present around the human oocyte and in the cumulus was examined following fixation in the presence of ruthenium red. An extracellular matrix comprising granules and filaments is present in the cumulus layer, in the corona radiata, in the outer pores of the zona pellucida and in the perivitelline space surrounding unfertilized oocytes. In replicate samples, the extracellular matrix comprised filaments which were mostly very long, occasionally cross-connected by shorter filaments, and usually decorated with numerous small granules.

Cytodifferentiation of mouse mammary epithelial cells cultured on a reconstituted basement membrane reveals striking similarities to development in vivo.

In the present study we provide evidence that the cytodifferentiation of primary mouse mammary epithelial cells within the alveolar-like structures formed after culture on a reconstituted basement membrane resembles development in vivo during late pregnancy and early lactation. During the first two days in culture on a basement membrane gel in the presence of lactogenic hormones, epithelial cells isolated from mid-pregnant mice are disorganized and central lumina are largely absent. Levels of mRNA for the milk proteins, beta-casein and transferrin, are dramatically reduced.

Modulation of milk protein synthesis through alteration of the cytoskeleton in mouse mammary epithelial cells cultured on a reconstituted basement membrane.

Recent studies indicate that the cytoskeleton may be involved in modulating tissue-specific gene expression in mammalian cells. We have studied the role of the cytoskeleton in regulating milk protein synthesis and secretion by primary mouse mammary epithelial cells cultured on a reconstituted basement membrane that promotes differentiation. After 8 days in culture, cells were treated with cytochalasin D (CD) (0.