Publications

Nuclear positioning is a crucial cell function, but how a migrating cell positions its nucleus is not understood. Using traction-force microscopy, we found that the position of the nucleus in migrating fibroblasts closely coincided with the center point of the traction-force balance, called the point of maximum tension (PMT). Positioning of the nucleus close to the PMT required nucleus-cytoskeleton connections through linker of nucleoskeleton-to-cytoskeleton (LINC) complexes. Although the nucleus briefly lagged behind the PMT following spontaneous detachment of the uropod during migration, the nucleus quickly repositioned to the PMT within a few minutes. Moreover, traction-generating spontaneous protrusions deformed the nearby nucleus surface to pull the nuclear centroid toward the new PMT, and subsequent retraction of these protrusions relaxed the nuclear deformation and restored the nucleus to its original position. We propose that the protruding or retracting cell boundary transmits a force to the surface of the nucleus through the intervening cytoskeletal network connected by the LINC complexes, and that these forces help to position the nucleus centrally and allow the nucleus to efficiently propagate traction forces across the length of the cell during migration.

There are wide disparities in breast cancer-specific survival by patient sociodemographic characteristics. Women of lower income, for instance, have higher relapse and death rates from breast cancer. One possible contributing factor for this disparity is low use of adjuvant endocrine therapy-an extremely efficacious therapy in women with early stage, hormone receptor positive breast cancer, the most common subtype of breast cancer. Alone, adjuvant endocrine therapy decreases breast cancer recurrence by 50% and death by 30%. Data suggest that low use of adjuvant endocrine therapy is a potentially important and modifiable risk factor for poor outcome in low-income breast cancer patients.

OBJECTIVE

To determine the time to benefit of using flexible sigmoidoscopy for colorectal cancer screening.

DESIGN

Survival meta-analysis.

DATA SOURCES

A Cochrane Collaboration systematic review published in 2013, Medline, and Cochrane Library databases.

ELIGIBILITY CRITERIA

Randomized controlled trials comparing screening flexible sigmoidoscopy with no screening. Trials with fewer than 100 flexible sigmoidoscopy screenings were excluded.

RESULTS

Four studies were eligible (total n = 459,814). They were similar for patients' age (50-74 years), length of follow-up (11.2-11.9 years), and relative risk for colorectal cancer related mortality (0.69-0.78 with flexible sigmoidoscopy screening). For every 1000 people screened at five and 10 years, 0.3 and 1.2 colorectal cancer related deaths, respectively, were prevented. It took 4.3 years (95% confidence interval 2.8 to 5.8) to observe an absolute risk reduction of 0.0002 (one colorectal cancer related death prevented for every 5000 flexible sigmoidoscopy screenings). It took 9.4 years (7.6 to 11.3) to observe an absolute risk reduction of 0.001 (one colorectal cancer related death prevented for every 1000 flexible sigmoidoscopy screenings).

CONCLUSION

Our findings suggest that screening flexible sigmoidoscopy is most appropriate for older adults with a life expectancy greater than approximately 10 years.

OBJECTIVES

To investigate the relationship between multimorbidity and healthcare utilisation patterns among the highest cost patients in a large, integrated healthcare system.

DESIGN

In this retrospective cross-sectional study of all patients in the U.S. Veterans Affairs (VA) Health Care System, we aggregated costs of individuals' outpatient and inpatient care, pharmacy services and VA-sponsored contract care received in 2010. We assessed chronic condition prevalence, multimorbidity as measured by comorbidity count, and multisystem multimorbidity (number of body systems affected by chronic conditions) among the 5% highest cost patients. Using multivariate regression, we examined the association between multimorbidity and healthcare utilisation and costs, adjusting for age, sex, race/ethnicity, marital status, homelessness and health insurance status.

SETTING

USA VA Health Care System.

PARTICIPANTS

5.2 million VA patients.

MEASURES

Annual total costs; absolute and share of costs generated through outpatient, inpatient, pharmacy and VA-sponsored contract care; number of visits to primary, specialty and mental healthcare; number of emergency department visits and hospitalisations.

RESULTS

The 5% highest cost patients (n=261,699) accounted for 47% of total VA costs. Approximately two-thirds of these patients had chronic conditions affecting ≥3 body systems. Patients with cancer and schizophrenia were less likely to have documented comorbid conditions than other high-cost patients. Multimorbidity was generally associated with greater outpatient and inpatient utilisation. However, increased multisystem multimorbidity was associated with a higher outpatient share of total costs (1.6 percentage points per affected body system, p<0.01) but a lower inpatient share of total costs (-0.6 percentage points per affected body system, p<0.01).

CONCLUSIONS

Multisystem multimorbidity is common among high-cost VA patients. While some patients might benefit from disease-specific programmes, for most patients with multimorbidity there is a need for interventions that coordinate and maximise efficiency of outpatient services across multiple conditions.