Bleomycin induces strand breakage in DNA through disruption of glycosidic linkages. We investigated the ability of bleomycin to damage yeast cell walls, which are composed primarily of carbohydrate. Bleomycin treatment of intact yeast cells facilitated enzymatic conversion of yeasts to spheroplasts. Bleomycin treatment also altered anchorage of mannoproteins to the cell wall matrix in intact cells or isolated cell walls. Cell surface mannoproteins were labelled with 12.5, and their solubilization was monitored. Seventeen hour treatments with bleomycin released some of the label directly into treatment supernatants and facilitated extraction of mannoproteins by dithiothreitol and lytic enzymes. Bleomycin treatments as short as 10 min caused changes in extraction of mannoproteins from intact cells. Specifically, cell wall anchorage of several mannoproteins was affected by the drug. There were drug-induced changes in extractability of mannoproteins with apparent molecular weights of 96,000, 80,000, 61,000, 41,000,31,500, and 21,000 (determined after deglycosylation with endo-N-acetylglucosaminidase H). The similarity of results obtained in the presence and absence of cycloheximide, the appearance of cell wall effects after only 10 min of treatment, and the similarity of effects in intact cells and isolated cell walls are consistent with direct drug-induced damage and inconsistent with a mechanism dependent on expression of bleomycin-damaged genes or other intracellular mediators. The results are consistent with bleomycin-mediated increases in cell wall permeability through disruption of glycosidic cross-linking structures in the cell wall.

Lack of follow-up care for hypertension adversely affects health in urban communities. The authors designed this study to (1) evaluate the effectiveness of a specialized intervention program for hypertension follow-up and (2) evaluate the associations with loss to follow-up. They evaluated factors related to loss to follow-up to either a routine care medical clinic or a special primary care intervention program (the Competitive Initiative Program [CIP]). They also conducted interviews to provide in-depth information on the barriers to this program. They found that patients referred through the CIP were significantly more likely to receive follow-up care through a primary care provider. Cost of care, long waiting times, lack of physician continuity, and more pressing priorities explained the lack of follow-up care. Despite a program to provide health care at no cost to patients, lack of insurance and worries about cost are described as barriers to adequate follow-up for hypertension treatment.