Mitochondrial DNA damage by bleomycin induces AML cell death.

Mitochondria contain multiple copies of their own 16.6 kb circular genome. To explore the impact of mitochondrial DNA (mtDNA) damage on mitochondrial (mt) function and viability of AML cells, we screened a panel of DNA damaging chemotherapeutic agents to identify drugs that could damage mtDNA. We identified bleomycin as an agent that damaged mtDNA in AML cells at concentrations that induced cell death. Bleomycin also induced mtDNA damage in primary AML samples. Consistent with the observed mtDNA damage, bleomycin reduced mt mass and basal oxygen consumption in AML cells. We also demonstrated that the observed mtDNA damage was functionally important for bleomycin-induced cell death. Finally, bleomycin delayed tumor growth in xenograft mouse models of AML and anti-leukemic concentrations of the drug induced mtDNA damage in AML cells preferentially over normal lung tissue. Taken together, mtDNA-targeted therapy may be an effective strategy to target AML cells and bleomycin could be useful in the treatment of this disease.

Risk of injury associated with skeletal muscle relaxant use in older adults.

BACKGROUND: The use of skeletal muscle relaxants (SMRs) among older adults is associated with sedation and confusion, which may lead to an increased risk of falls and injuries. SMRs continue to be used among older adults, although they are on the Beers list as drugs to avoid in the elderly. OBJECTIVE: To investigate the relationship between SMR use and subsequent risk of injury. METHODS: This was a retrospective case-control study of members aged 65 years or older enrolled in an integrated health care system. Cases were defined as patients with a documented injury resulting in either a hospitalization or an emergency department or urgent care visit from January 2009 through December 2010. Cases were matched to controls in a 1:4 ratio by age and sex. Patients had to be enrolled and alive on the date of an injury (index date). SMR exposure for all cases and controls was evaluated within 60 days prior to the index date. Conditional logistic regression adjusted for covariates was performed, with risk estimates presented as odds ratios with 95% confidence intervals. RESULTS: From a base population of 322,806 older adults, we identified 27,974 cases of injury and 104,303 matched controls. Among the cases, 365 (1.30%) used an SMR; among the controls, 801 (0.77%) used an SMR in the 60 days prior to the index date. After adjustment for demographic and clinical covariates, risk of injury was significantly increased for patients using an SMR compared to no use (OR 1.32, 95% CI 1.16-1.50; p < 0.001). Carisoprodol was associated with an increased risk of injury (OR 1.73, 95% CI 1.04-2.88; p = 0.036), as were methocarbamol (OR 1.42, 95% CI 1.16-1.75; p = 0.001) and cyclobenzaprine (OR 1.22, 95% CI 1.02-1.45; p = 0.029). CONCLUSIONS: Older adults using SMRs have an increased risk of injury. These findings provide evidence to support current recommendations to avoid the use of SMRs in elderly patients.

Dementia and readmission risk in patients with heart failure participating in a transitional care program.

BACKGROUND: Cognitive impairment is prevalent in patients hospitalized for heart failure (HF). We aimed to generate further evidence on the value of dementia screening in hospitalized HF patients by examining whether and when dementia would be an independent risk factor for 30-day readmission while modeling permutations of known risk factors such as patient demographics, disease burden, prior utilization, and index hospitalization characteristics. METHODS AND RESULTS: A retrospective cohort study was employed, consisting of 26,128 patients (2,075 or 7.9% with dementia) in a transitional care program post HF hospitalization. The overall 30-day all-cause readmission rate was 18.1%. Patients with dementia had higher unadjusted rates of readmission (22.0 vs 17.8%) and death (4.5 vs. 2.2%) within 30 days post hospitalization, compared to those without dementia. Hierarchical multivariable proportional hazards regression results showed that dementia independently predicted readmission when both patient demographics and disease burden variables were controlled for (HR=1.15, p=0.02). However, the association between dementia and readmission was attenuated in the full model when prior utilization and index hospitalization characteristics were added (HR=1.04, p=0.55). For dementia patients, Charlson comorbidity index, prior ED visits, and length of stay were significant risk factors of readmission. CONCLUSIONS: The presence of dementia and the predictors of 30-day readmission in those with dementia may help identify this subset of high-risk HF patients for potential efforts to improve their prognosis.

Safety of baclofen versus tizanidine for older adults with musculoskeletal pain.

BACKGROUND: Baclofen and tizanidine are both muscle relaxants that carry the risk for neuropsychiatric events in older adults but there is a lack of data directly comparing their safety. This study aimed to investigate the relative risk between these two medications in causing injury and delirium in older adults. METHODS: This was a retrospective cohort study that was completed in an integrated healthcare system in the United States and included patients aged 65 years or older who started baclofen or tizanidine for the treatment of musculoskeletal pain from January 2016 through December 2018. Outcomes included new incidence of injury (concussion, contusion, dislocation, fall, fracture, or other injuries) and delirium. The cohort was followed from the initiation of therapy until the first occurrence of any of the following events: end of the index drug exposure, end of health plan membership, death, or the study end date of December 31st, 2019. Descriptive statistics were used to compare baseline patient characteristics between baclofen and tizanidine treatment groups. Cox proportional hazards model was used to calculate adjusted hazard ratios (HRs) with 95% confidence intervals. RESULTS: The final study cohort included 12,101 and 6,027 older adults in the baclofen and tizanidine group respectively (mean age 72.2 ± 6.2 years old, 59% female). Older adults newly started on baclofen had a greater risk of injury (HR = 1.54, 95% CI = 1.21-1.96, P = < 0.001) and delirium (HR = 3.33, 95% CI = 2.11-5.26, p = <0.001) compared to those started on tizanidine. CONCLUSION: The results of this study suggest that baclofen is associated with higher incidences of injury and delirium compared to tizanidine when used for the treatment of musculoskeletal pain. Future studies should investigate if these risks are dose-related and include a comparison group not exposed to either drug.

Refining the Definition of Polypharmacy and Its Link to Disability in Older Adults: Conceptualizing Necessary Polypharmacy, Unnecessary Polypharmacy, and Polypharmacy of Unclear Benefit.

The term polypharmacy in older adults is generally used in a pejorative context in the medical literature. Because of its link to geriatric syndromes and disability, the avoidance of polypharmacy is usually recommended in older adults as a strategy to optimize functional status. However, there are many polypharmacy regimens based on high-quality trials that clearly reduce the risk of disability in older adults. Other guidelines for older adults recommend the use of additional medications that may or may not be evidence based and that may or may not reduce disability. Therefore, we propose that, in the geriatric literature, polypharmacy now be categorized as "necessary polypharmacy," "unnecessary polypharmacy," or "polypharmacy of unclear benefit." In this article, we discuss the 3 categories of polypharmacy and give examples on each polypharmacy regimen and its potential relationship to disability in older adults.

Age-Dependent Hemoglobin A1c Therapeutic Targets Reduce Diabetic Medication Changes in the Elderly.

OBJECTIVE: To assess whether implementation of age-dependent therapeutic targets for high hemoglobin A1c (HbA1c) changed clinicians' ordering of diabetes medications for older adults. BACKGROUND: In 2016, Kaiser Permanente Southern California (KPSC) changed the therapeutic targets for alerting clinicians about high HbA1c results in the electronic health record, KP HealthConnect (KPHC). Previously, all HbA1c results ≥7.0 percent were flagged as high in adult patients with diabetes. Starting in 2016, HbA1c therapeutic targets were relaxed to <7.5 percent for patients age 65 to 75, and to <8.0 percent for patients over age 75 to reduce treatment intensity and adverse events. METHODS: This retrospective analysis used logistic regression models to calculate the change in odds of a medication change following an HbA1c result after age-dependent HbA1c flags were introduced. RESULTS: The odds of medication change decreased among patients whose HbA1c targets were relaxed: Odds Ratio (OR) 0.72 (95 percent CI 0.67-0.76) for patients age 65-75 and HbA1c 7.0 percent-7.5 percent; OR 0.72 (95 percent CI 0.65-0.80) for patients over age 75 and HbA1c 7.0 percent-7.5 percent; and OR 0.67 (95 percent CI 0.61-0.75) for patients over age 75 and HbA1c 7.5 percent-8.0 percent. In the age and HbA1c ranges for which the alerts did not change, the odds of medication change generally increased or stayed the same. There was little evidence of medication de-intensification in any group. CONCLUSIONS: These findings suggest that the change in therapeutic targets was associated with a reduction in medication intensification among older adults with diabetes.

The Risk of Pneumonia in Older Adults Using Nonbenzodiazepine Hypnotics.

BACKGROUND: Previous studies have shown an increased risk of pneumonia with benzodiazepines (BZD) and an increased risk of any infection with non-BZD hypnotics, but no analysis has specifically investigated the risk of pneumonia with non-BZD hypnotic use. OBJECTIVE: To evaluate the risk of pneumonia associated with non-BZD hypnotic use in the elderly. METHODS: This was a retrospective case-control study of members aged 65 years and older enrolled in an integrated health care system. Cases were identified as patients aged 65 years and older with a diagnosis of pneumonia from January 2011 to December 2012. Controls were matched in a 4:1 ratio to cases based on age, gender, and active enrollment. Non-BZD hypnotic exposure was evaluated for all cases and controls 1 year before the index date. Proximity of exposure to index date and duration of use were analyzed. Conditional logistic regression adjusted for covariates was performed. RESULTS: We identified 51,029 cases with pneumonia and matched 188,391 controls without pneumonia. Of the cases with pneumonia, 5.5% (2,790) of cases had exposure to a non-BZD hypnotic, compared with 3.4% (6,345) of controls. Non-BZD hypnotic exposure was associated with an increased risk of pneumonia (OR = 1.14; 95% CI = 1.08-1.20). When exposure was stratified by proximity to index date, only current exposure was associated with an increased risk of pneumonia (OR = 1.27; 95% CI = 1.18-1.36). Short-term exposure was associated with a relatively higher risk of pneumonia (OR = 1.57; 95% CI = 1.39-1.77) compared with long-term use (OR = 1.16; 95% CI = 1.06-1.25). CONCLUSIONS: Current use of non-BZD hypnotics in older adults is associated with an increased risk of pneumonia. The findings of this study provide additional support for reducing the use of non-BZD hypnotics in older adults and for pursuing safer alternatives for treating insomnia. DISCLOSURES: No outside funding supported this study. At the time of this study, Jung was a PGY2 resident in drug information at Kaiser Permanente Drug Information Services. All authors are employed by Kaiser Permanente and report no other potential financial conflicts of interest. Study concept and design were contributed by Jung, Spence, Lee, and Gibbs. Jung, Spence, and Hui were responsible for data collection, and data interpretation was performed by Jung and Spence, with assistance from Escasa, Lee, and Hui. The manuscript was primarily written by Jung, along with Spence and Escasa, and revised by Spence, Escasa, and Lee, along with the other authors.

Improving Care in Older Patients with Diabetes: A Focus on Glycemic Control.

Diabetes affects more than 25% of Americans older than age 65 years. The medical care of older patients must differ from the care of their younger counterparts. Older patients are at high risk of drug toxicity. A hemoglobin A1c (HbA1c) level less than 7.0% has historically been the goal of all patients with diabetes, regardless of age. Recent research has demonstrated that using medications to achieve such tight glycemic control is not necessary and is often not safe.This article discusses the seminal research findings that strongly suggest that HbA1c goals should be relaxed in older patients. The authors then recommend an age-specific and functionally appropriate HbA1c reference range for patients receiving medications to improve glycemic control. Other interventions are suggested that should make diabetes care safer in older patients receiving hypoglycemic medications.

Inactivation of the mitotic checkpoint as a determinant of the efficacy of microtubule-targeted drugs in killing human cancer cells.

Drugs that disrupt microtubule dynamics include some of the most important of cancer chemotherapies. While these drugs, which include paclitaxel (Taxol), are known to invoke the mitotic checkpoint, the factors that determine cancer cell killing remain incompletely characterized. Cells that are relatively resistant to killing by these drugs block robustly in mitosis, whereas cells sensitive to killing block only transiently in mitosis before undergoing nuclear fragmentation and death. Passage through mitosis was an absolute requirement of drug-induced death, because death was markedly reduced in cells blocked at both G(1)-S and G(2). Cell killing was at least in part linked to the absence or inactivation of BubR1, a kinetochore-associated phosphoprotein that mediates the mitotic checkpoint. Sensitivity to paclitaxel correlated with decreased BubR1 protein expression in human cancer cell lines, including those derived from breast and ovarian cancers. Silencing of BubR1 via RNA interference inactivated the mitotic checkpoint in drug-resistant cells, and reversed resistance to paclitaxel and nocodazole. Together, these results suggest that the mitotic checkpoint is an important determinant of the efficacy of microtubule-targeting drugs in killing cancer cells, potentially providing novel targets for increasing treatment efficacy.

Risk of Injury in Older Adults Using Gastrointestinal Antispasmodic and Anticholinergic Medications.

OBJECTIVES: To determine the risk of injury associated with gastrointestinal (GI) antispasmodic and anticholinergic use in elderly adults. DESIGN: Retrospective case-control study. SETTING: Integrated healthcare system. PARTICIPANTS: Healthcare system members aged 65 and older (N = 260,010; 54,152 cases, 205,858 controls). MEASUREMENTS: Cases were identified as individuals with an injury resulting in a hospitalization, emergency department, or urgent care visit (index date) from January 2009 through December 2010. Cases and controls were matched in a 1:4 ratio based on age and sex. GI antispasmodic and anticholinergic current and past exposure for cases and controls was evaluated. Individuals were classified as current users if the days' supply of the GI prescription overlapped the index date and past users if the days' supply ended more than 60 days before the index date. Duration of use for current users was analyzed for short- and long-term use. Conditional logistic regression produced adjusted odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Of the total population, 1,068 (0.4%) had current exposure to a GI antispasmodic or anticholinergic (302 (0.6%) cases, 766 (0.4%) controls). Current users had a small but significantly greater risk of injury than nonusers (OR = 1.16, 95% CI = 1.01-1.34, P = .03). Past use was not significantly different from no use. Short-term users had a significantly greater risk of injury (OR = 1.31, 95% CI = 1.01-1.70, P = .04) than nonusers. Long-term use was associated with greater risk, but the difference was not statistically significant. CONCLUSION: Older adults using GI antispasmodic and anticholinergic drugs have greater risk of injury. These findings support recommendations to limit the prescribing of GI antispasmodics and anticholinergics in elderly adults.

Targeting Mitochondria with Avocatin B Induces Selective Leukemia Cell Death.

Treatment regimens for acute myeloid leukemia (AML) continue to offer weak clinical outcomes. Through a high-throughput cell-based screen, we identified avocatin B, a lipid derived from avocado fruit, as a novel compound with cytotoxic activity in AML. Avocatin B reduced human primary AML cell viability without effect on normal peripheral blood stem cells. Functional stem cell assays demonstrated selectivity toward AML progenitor and stem cells without effects on normal hematopoietic stem cells. Mechanistic investigations indicated that cytotoxicity relied on mitochondrial localization, as cells lacking functional mitochondria or CPT1, the enzyme that facilitates mitochondria lipid transport, were insensitive to avocatin B. Furthermore, avocatin B inhibited fatty acid oxidation and decreased NADPH levels, resulting in ROS-dependent leukemia cell death characterized by the release of mitochondrial proteins, apoptosis-inducing factor, and cytochrome c. This study reveals a novel strategy for selective leukemia cell eradication based on a specific difference in mitochondrial function.

DNA ministrings: highly safe and effective gene delivery vectors.

Conventional plasmid DNA vectors play a significant role in gene therapy, but they also have considerable limitations: they can elicit adverse immune responses because of bacterial sequences they contain for maintenance and amplification in prokaryotes, their bioavailability is compromised because of their large molecular size, and they may be genotoxic. We constructed an in vivo platform to produce ministring DNA-mini linear covalently closed DNA vectors-that are devoid of unwanted bacterial sequences and encode only the gene(s) of interest and necessary eukaryotic expression elements. Transfection of rapidly and slowly dividing human cells with ministring DNA coding for enhanced green fluorescent protein resulted in significantly improved transfection, bioavailability, and cytoplasmic kinetics compared with parental plasmid precursors and isogenic circular covalently closed DNA counterparts. Ministring DNA that integrated into the genome of human cells caused chromosomal disruption and apoptotic death of possibly oncogenic vector integrants; thus, they may be safer than plasmid and circular DNA vectors.

Glucopsychosine increases cytosolic calcium to induce calpain-mediated apoptosis of acute myeloid leukemia cells.

To identify novel anti-cancer agents, we created and screened a unique nutraceutical library for activity against acute myeloid leukemia (AML) cells. From this screen, we determined that glucopsychosine was selectively toxic toward AML cell lines and primary AML patient samples with no effect toward normal hematopoietic cells. It delayed tumor growth and reduced tumor weights in mouse xenograft models without imparting toxicity. Glucopsychosine increased cytosolic calcium and induced apoptosis through calpain enzymes. Extracellular calcium was functionally important for glucopsychosine-induced AML cell death and surface calcium channel expression is altered in AML cells highlighting a unique mechanism of glucopsychosine's selectivity.

Making hospitals safer for older adults: updating quality metrics by understanding hospital-acquired delirium and its link to falls.

The medical care of hospitalized geriatric patients must differ from the care of younger adults. Because of reduced "reserve capacity," hospitalized older adults are at high risk of development of geriatric syndromes such as delirium and falls. Geriatric syndromes often lead to functional decline and dependence. Patients who experience geriatric syndromes in the hospital are more likely to have a longer length of stay, higher risk of readmissions, and worse medical outcomes. Incident delirium in hospitalized geriatric patients has been shown to be preventable by intervening in established risk factors. Prevention of hospital-related falls has not been consistently demonstrated. Analysis from Kaiser Permanente data demonstrated a correlation with delirium and hospital-related falls. We propose that age-specific quality metrics should be made to reduce the risk of the development of geriatric syndromes in hospitalized older adults. By preventing delirium, we believe that health care practitioners can reduce hospital-related falls in geriatric patients and improve the quality of care delivered to hospitalized older adults. An illustrative fictional case study is presented.

Making the hospital safer for older adult patients: a focus on the indwelling urinary catheter.

The needs of hospitalized geriatric patients differ from the needs of hospitalized younger adults. In an attempt to improve systems of care for the older adult, the Centers for Medicare and Medicaid Services classified urinary tract infections related to the use of indwelling urinary catheters (IUC) as one of eight "never events." The insertion of an IUC is a commonly performed procedure that can cause an array of iatrogenic complications. In addition, the placement of an IUC without medical indication is a risk factor for prolonged hospitalization and inpatient mortality. Foley catheterization has been documented as a culprit in urosepsis and as being associated with geriatric syndromes such as delirium and functional impairment. This article will discuss the indications for the IUC, the complications that can occur because of the IUC, and comment on the Kaiser Permanente Southern California Region's efforts to minimize the unnecessary use of the IUC. Thoughtful and judicious use of the IUC, such as minimizing the use of urinary catheterization, either by not inserting an IUC or by removing it as soon as it is no longer needed, will most likely reduce inpatient morbidity and improve the health of the hospitalized older adult.