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Free radical damage can have fatal consequences. Mitochondria carry out essential cellular functions and produce high levels of reactive oxygen species (ROS). Many agents also generate ROS. Using the yeast Saccharomyces cerevisiae as a eukaryotic model, the role of functional mitochondria in surviving free radical damage was investigated. Respiratory-deficient cells lacking mitochondrial DNA (rho(0)) were up to 100-fold more resistant than isogenic rho(+) cells to killing by ROS generated by the bleomycin-phleomycin family of oxidative agents. Up to approximately 90% of the survivors of high oxidative stress lost mitochondrial function and became "petites." The selective advantage of respiratory deficiency was studied in several strains, including DNA repair-deficient rad52/rad52 and blm5/blm5 diploid strains. These mutant strains are hypersensitive to lethal effects of free radicals and accumulate more DNA damage than related wild-type strains. Losses in mitochondrial function were dose-dependent, and mutational alteration of the RAD52 or BLM5 gene did not affect the resistance of surviving cells lacking mitochondrial function. The results indicate that inactivation of mitochondrial function protects cells against lethal effects of oxygen free radicals.

Cancer is the leading cause of death in older adults aged 60 to 79 years. The biology of certain cancers and responsiveness to therapy changes with the patient's age. Advanced age alone should not preclude the use of effective treatment that could improve quality of life or extend meaningful survival. The challenge of managing older patients with cancer is to assess whether the expected benefits of treatment are superior to the risk in a population with decreased life expectancy and decreased tolerance to stress. These guidelines provide an approach to decision-making in older cancer patients based on comprehensive geriatric assessment and also include disease specific issues related to age in the management of some cancer types in older adults.

Chromosomal repair was studied in stationary-phase Saccharomyces cerevisiae, including rad52/rad52 mutant strains deficient in repairing double-strand breaks (DSBs) by homologous recombination. Mutant strains suffered more chromosomal fragmentation than RAD52/RAD52 strains after treatments with cobalt-60 γ irradiation or radiomimetic bleomycin, except after high bleomycin doses when chromosomes from rad52/rad52 strains contained fewer DSBs than chromosomes from RAD52/RAD52 strains. DNAs from both genotypes exhibited quick rejoining following γ irradiation and sedimentation in isokinetic alkaline sucrose gradients, but only chromosomes from RAD52/RAD52 strains exhibited slower rejoining (10 min to 4 hr in growth medium). Chromosomal DSBs introduced by γ irradiation and bleomycin were analyzed after pulsed-field gel electrophoresis. After equitoxic damage by both DNA-damaging agents, chromosomes in rad52/rad52 cells were reconstructed under nongrowth conditions [liquid holding (LH)]. Up to 100% of DSBs were eliminated and survival increased in RAD52/RAD52 and rad52/rad52 strains. After low doses, chromosomes were sometimes degraded and reconstructed during LH. Chromosomal reconstruction in rad52/rad52 strains was dose dependent after γ irradiation, but greater after high, rather than low, bleomycin doses with or without LH. These results suggest that a threshold of DSBs is the requisite signal for DNA-damage-inducible repair, and that nonhomologous end-joining repair or another repair function is a dominant mechanism in S. cerevisiae when homologous recombination is impaired.

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 125I, 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.

The Vanderbilt Evidence-based Practice Center systematically reviewed evidence on treatment of overactive bladder (OAB), urge urinary incontinence, and related symptoms. We focused on prevalence and incidence, treatment outcomes, comparisons of treatments, modifiers of outcomes, and costs.We searched PubMed, MEDLINE, EMBASE, and CINAHL.We included studies published in English from January 1966 to October 2008. We excluded studies with fewer than 50 participants, fewer than 75 percent women, or lack of relevance to OAB. Of 232 included publications, 20 were good quality, 145 were fair, and 67 poor. We calculated weighted averages of outcome effects and conducted a mixed-effects meta-analysis to investigate outcomes of pharmacologic treatments across studies.OAB affects more than 10 to 15 percent of adult women, with 5 to 10 percent experiencing urge urinary incontinence (UUI) monthly or more often. Six available medications are effective in short term studies: estimates from meta-analysis models suggest extended release forms (taken once a day) reduce UUI by 1.78 (95 percent confidence interval (CI): 1.61, 1.94) episodes per day, and voids by 2.24 (95 percent CI: 2.03, 2.46) per day. Immediate release forms (taken twice or more a day) reduce UUI by 1.46 (95 percent CI: 1.28, 1.64), and voids by 2.17 (95 percent CI: 1.81, 2.54). As context, placebo reduces UUI episodes by 1.08 (95 percent CI: 0.86, 1.30), and voids by 1.48 (95 percent CI: 1.19, 1.71) per day. No one drug was definitively superior to others, including comparison of newer more selective agents to older antimuscarinics. Current evidence is insufficient to guide choice of other therapies including sacral neuromodulation, instillation of oxybutynin, and injections of botulinum toxin. Acupuncture was the sole complementary and alternative medicine treatment, among reflexology and hypnosis, with early evidence of benefit. The strength of the evidence is insufficient to fully inform choice of these treatments. Select behavioral interventions were associated with symptom improvements comparable to medications. Limited evidence suggests no clear benefit from adding behavioral interventions at the time of initiation of pharmacologic treatment.OAB and associated symptoms are common. Treatment effects are modest. Quality of life and treatment satisfaction measures suggest such improvements can be important to women. The amount of high quality literature available is meager for helping guide women's choices. Gaps include weak or absent data about long-term followup, poorly characterized and potentially concerning harms, information about best choices to minimize side effects, and study of how combinations of approaches may best be used. This is problematic since the condition is chronic and a single treatment modality is unlikely to fully resolve symptoms for most women.

When the essential and distinctive cell walls of either pathogenic or nonpathogenic fungi break, cytoplasmic membranes rupture and fungi die. This fungicidal activity was discovered previously on nonproliferating Saccharomyces cerevisiae cells treated briefly with the oxidative tool and anticancer drug family of bleomycins. The present studies investigated effects of bleomycin on growing fungal organisms. These included the medically important Aspergillus fumigatus and Cryptococcus neoformans , as well as the emerging human pathogen and fungal model, S. cerevisiae. Bleomycin had its highest potency against A. fumigatus . Scanning electron microscopy and thin-section transmission electron microscopy were used to study morphological growth characteristics. Killing and growth inhibition were also measured. Long, thin, and segmented hyphae were observed when A. fumigatus was grown without bleomycin but were never observed when the mold was grown with the drug. Bleomycin arrested conidial germination, hyphal development, and the progression and completion of cell wall septation. Similarly, the drug inhibited the construction of yeast cell wall septa, preventing cytokinesis and progression in the cell division cycle of S. cerevisiae . Even when cytoplasms of mother and daughter cells separated, septation and cell division did not necessarily occur. Bizarre cell configurations, abnormally thickened cell walls at mother-daughter necks, abnormal polarized growth, large undivided cells, fragmented cells, and empty cell ghosts were also produced. This is the first report of a fungicidal agent that arrests fungal growth and development, septum formation, and cytokinesis and that also preferentially localizes to cell walls and alters isolated cell walls as well as intact cell walls on nongrowing cells.

Extensive lesions were produced in cell walls of Saccharomyces cerevisiae by the bleomycin family of anticancer antibiotics (30 min to 4 h). Electron micrographs revealed that the alterations were most frequently large breaks and small interruptions or holes in cell walls, which sometimes extended into cell membranes. Large portions of cell walls were sometimes lost. Cell walls were frequently ruptured in one or more positions. More than 75% of bud scar regions in single-plane sections and all bud scars in serial sections exhibited many interruptions and breaks after 3 or 4 h of treatment. The discovery of extensive damage to cell walls was consistent with the preferential (approximately 70%) association of radiolabeled bleomycin with cell walls and perimeters of bud scar regions after short exposures (30 min). After longer exposures, the distribution of silver grains changed from a predominant association with cell walls (30 min) to an increased association with the cell cytoplasm (1 to 4 h). This correlated with increased ultrastructural damage, since damage to cell walls was generally more frequent and more severe with increasing length of treatment (30 min to 4 h) or dose (25 to 100 micrograms/ml). Although DNA lesions are believed to be the lethal properties of bleomycins, the lesions produced in cell walls are also lethal properties of the antibiotics. The distributions of lesions on cell walls suggested a generalized interaction of the antibiotic with a cell wall component. These results led us to hypothesize a mechanism of effective antifungal action for the bleomycin family of antibiotics.