Co-cultivation of rat pneumocytes and bovine endothelial cells on a liquid-air interface.

The blood-air barrier is a most important functional element of the lung but little information is available about the cells constituting this barrier in vivo. The aim of the present study was to create an in vitro model of the blood-air barrier that would allow investigation of cellular interactions and alveolar metabolism, and would be suitable for in vitro drug screening. Rat pneumocytes and bovine microvascular endothelial cells were grown on opposite sides of microporous polycarbonate filters, as immersion, perfusion and liquid-air interface (LAI) cultures.

A H1 hemagglutinin of a human influenza A virus with a carbohydrate-modulated receptor binding site and an unusual cleavage site.

Two receptor binding variants of the influenza virus A/Tübingen/12/85 (H1N1) were separated by their different plaque formation in MDCK cells. Hemagglutination of variant I was restricted to red blood cells of guinea pigs, whereas variant II also hemagglutinated chicken cells. The variants differed also in their ability to bind to alpha 2,6-linked sialic acid.

Effect of functional stimulation on ascorbate content in phagocytes under physiological and pathological conditions.

Neutrophil polymorphonuclear leucocytes and macrophages contain 10-40 times increased intracellular ascorbate concentrations compared to plasma. A slight decrease of ascorbate content could be observed in total white blood cells and in monocytes upon stimulation with opsonized zymosan. These decreases were more pronounced in peritoneal and alveolar macrophages from rats.

The role of ascorbic acid in carcinogenesis.

Vitamin C is an essential nutrient whose protective role in carcinogenesis has been discussed for more than 50 years. Epidemiologic studies suggest that the consumption of vitamin C-rich foods is associated with a lower risk of cancers of the esophagus and stomach. The observation that cancer patients have low leukocyte vitamin C levels led to therapeutic trials the results of which are controversial; the hypothesis that vitamin C acts like a drug must be questioned.

The failure of ascorbic acid therapy to alter the induction or remission of murine amyloidosis.

It has been claimed that ascorbic acid enhances the in vitro degradation of AA amyloid fibrils. This raises the possibility that ascorbic acid may be of benefit in systemic AA amyloidosis, a condition with serious morbidity and mortality for which there is as yet no specific treatment. The effect was therefore tested of oral or injected supplements of ascorbic acid on the induction of AA amyloidosis in mice.

alpha 1-Microglobulin from normal and pathological urines.

alpha 1-Microglobulin was purified from normal and pathological urines. Significant differences were found in the amino acid compositions of the alpha 1-microglobulin isolated from these two sources. In addition electrofocusing of alpha 1-microglobulin from normal urine gave rise to two peaks of equal intensity with rather acidic isoelectric points (3.

Structural and functional similarities between mitochondrial malate dehydrogenase and L-3-hydroxyacyl CoA dehydrogenase.

Pig heart mitochondrial malate dehydrogenase (EC 1.1.1.