Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2015
2015
2015
2015
BACKGROUND
extracellular matrix (ECM) components are instrumental in maintaining homeostasis and muscle fiber functional integrity. Skeletal muscle hypertrophy is associated with ECM remodeling. Specifically, recent studies have reported the involvement of matrix metalloproteinases (MMPs) in muscle ECM remodeling. However, the functional role of MMPs in muscle hypertrophy remains largely unknown.
METHODS
in this study, we examined the role of MMP-2 in skeletal muscle hypertrophy using a previously validated method where the plantaris muscle of mice were subjected to mechanical overload due to the surgical removal of synergist muscles (gastrocnemius and soleus).
RESULTS
following two weeks of overload, we observed a significant increase in MMP-2 activity and up-regulation of ECM components and remodeling enzymes in the plantaris muscles of wild-type mice. However, MMP-2 knockout mice developed significantly less hypertrophy and ECM remodeling in response to overload compared to their wild-type littermates. Investigation of protein synthesis rate and Akt/mTOR signaling revealed no difference between wild-type and MMP-2 knockout mice, suggesting that a difference in hypertrophy was independent of protein synthesis.
CONCLUSION
taken together, our results suggest that MMP-2 is a key mediator of ECM remodeling in the setting of skeletal muscle hypertrophy.
View on PubMed2015
OBJECTIVE
The aim of this study was to evaluate ethnic differences in burden of prevalent geriatric conditions and diabetic complications among older, insured adults with diabetes.
METHOD
An observational study was conducted among 115,538 diabetes patients, aged ≥60, in an integrated health care system with uniform access to care.
RESULTS
Compared with Whites, Asians and Filipinos were more likely to be underweight but had substantively lower prevalence of falls, urinary incontinence, polypharmacy, depression, and chronic pain, and were least likely of all groups to have at least one geriatric condition. African Americans had significantly lower prevalence of incontinence and falls, but higher prevalence of dementia; Latinos had a lower prevalence of falls. Except for end-stage renal disease (ESRD), Whites tended to have the highest rates of prevalent diabetic complications.
DISCUSSION
Among these insured older adults, ethnic health patterns varied substantially; differences were frequently small and rates were often better among select minority groups, suggesting progress toward the Healthy People 2020 objective to reduce health disparities.
View on PubMed2015
2015
2015
2015
2015
OBJECTIVES
Targeting high Tuberculosis (TB) transmission sites may offer a novel approach to TB prevention in sub-Saharan Africa. We sought to characterise TB transmission sites in a rural Ugandan township.
METHODS
We recruited adults starting TB treatment in Tororo, Uganda, over 1 year. Fifty four TB cases provided names of frequent contacts, sites of residence, health care, work and social activities, and two sputum samples. Mycobacterium tuberculosis (MTB) culture-positive specimens underwent spoligotyping to identify strains with shared genotypes. We visualised TB case social networks, and obtained, mapped and geo-coded global positioning system measures for every location that cases reported frequenting 1 month before treatment. Locations of spatial overlap among genotype-clustered cases were considered potential transmission sites.
RESULTS
Six distinct genotypic clusters were identified involving 21 of 33 (64%) MTB culture-positive, genotyped cases; none shared a home. Although 18 of 54 (33%) TB cases shared social network ties, none of the genotype-clustered cases shared social ties. Using spatial analysis, we identified potential sites of within-cluster TB transmission for five of six genotypic clusters. All sites but one were healthcare and social venues, including sites of drinking, worship and marketplaces. Cases reported spending the largest proportion of pre-treatment person-time (22.4%) at drinking venues.
CONCLUSIONS
Using molecular epidemiology, geospatial and social network data from adult TB cases identified at clinics, we quantified person-time spent at high-risk locations across a rural Ugandan community and determined the most likely sites of recent TB transmission to be healthcare and social venues. These sites may not have been identified using contact investigation alone.
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