TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: Somatic cells in vitro have a finite life expectancy before entering a state of senescence, but it is unclear whether this state occurs in vivo in kidney development, growth, and aging. We previously showed that human kidney cortex displays telomere shortening with age. In this study, we compared the structural and functional changes in rat kidney with age to phenomena associated with cellular senescence in vitro.', 'We assessed the changes in Fischer 344 rat kidneys from age 1 to 9 months to define growth and development and from age 9 to 24 months to define aging.', 'Rat kidney telomeres were approximately 35 to 40 kb long and did not shorten significantly. Expression of mRNA for p16INK4a, a characteristic senescence gene in vitro, was undetectable in most young rats but rose 27 fold during growth and a further 72-fold during aging. p16INK4a protein was localized to the nucleus and increased with age. p16INK4a mRNA also increased in other tissues. Lipofuscin and senescence-associated beta-galactosidase increased in epithelium with growth and aging and their occurrence was significantly associated with each other. Lipofuscin was particularly found in atrophic nephrons.\Question: Does cell senescence in rat kidneys in vivo increase with growth and age despite lack of telomere shortening?

SOLUTION: We conclude that cell senescence occurs in both growth and aging in rat kidney and may contribute to the age-related pathology. These changes are not due to telomere shortening, but may reflect cumulative environmental stress.

PROBLEM: Context: In humans, glucocorticoid-induced osteoporosis is the most common cause of medication-induced osteoporosis. Recent clinical data suggest that glucocorticoid therapy increases the risk of vertebral fractures within a short treatment period. Therefore, this study aimed at investigating vertebral bone in a rat model of glucocorticoid-induced postmenopausal osteoporosis.', 'Fifty Sprague-Dawley rats were randomly assigned into three groups: 1) untreated controls, 2) Sham-operated group, and 3) ovariectomized rats treated with glucocorticoid (dexamethasone) for 3 months (3M) after recovery from bilateral ovariectomy. Osteoporotic bone status was determined by means of the gold standard dual energy X-ray absorptiometry (DEXA) scan. Vertebral bodies were examined using µCT, histological analysis, mRNA expression analysis, and biomechanical compression testing. Further systemic effects were studied biochemically using serum marker analysis.', 'Dexamethasone treatment showed at 3M a significantly lower bone mineral density in ovariectomized rats compared to Sham-operated control (p < 0.0001) as analyzed in vivo by DEXA. Furthermore, Z scores reached levels of -5.7 in the spine indicating sever osteoporotic bone status. Biomechanical testing of compression stability indicated a lower functional competence (p < 0.0001) in the spine of treated rats. µCT analysis showed significant reduction of bone volume density (BV/TV%; p < 0.0001), significantly enhanced trabecular spacing (Tb.Sp; p < 0.0001) with less trabecular number (Tb.N; p < 0.001) and complete loss of trabecular structures in glucocorticoid-treated ovariectomized rats. Histological analysis by osteoblast and osteoclast activities reflected a higher bone catabolism reflected by osteoclast counts by TRAP (p < 0.019) and lower bone catabolism indicated by ALP-stained area (p < 0.035).Serum analysis showed a significant increase in osteocalcin (p < 0.0001), osteopontin (p < 0.01) and insulin (p < 0.001) at 3M. Expression analysis of molecular markers in the vertebral body revealed lower expression in tenascin C in the OVX-steroid animals at 3M.\Question: Does short-term glucocorticoid treatment cause spinal osteoporosis in ovariectomized rats?

SOLUTION: Short-term glucocorticoid treatment of ovariectomized rats indicates according to DEXA standards a severe osteoporotic bone status in vertebral bone. Nonetheless, dysfunctional bone anabolism and enhanced bone catabolism are observed. Alterations of bone extracellular matrix proteins that correlate to inferior mechanical stability and affected microstructure were noticed and suggest further investigation. Treatment with dexamethasone was also seen to affect insulin and osteopontin levels and thus osteoblast function and maturation. This described animal model presents a recapitulation of clinically obtained data from early phase glucocorticoid-induced osteoporosis observed in patients.

PROBLEM: Context: The purpose of this study is to examine the effect of insurance coverage on stage of presentation, treatment, and survival of head and neck cancer (HNC).', 'A retrospective study was conducted using the Surveillance, Epidemiology, and End Results (SEER) program to identify patients diagnosed with HNC. The primary variable of interest was insurance analyzed as a dichotomous variable: Patients were considered uninsured if they were classified as "uninsured" by SEER, whereas patients were considered insured if they were defined by SEER as "any Medicaid," "insured," or "insured/no specifics." The outcomes of interest were cancer stage at presentation (M0 vs M1), receipt of definitive treatment, and HNC-specific mortality (HNCSM). Multivariable logistic regression modeled the association between insurance status and stage at presentation, as well as between insurance status and receipt of definitive treatment, whereas HNCSM was modeled using Fine and Gray competing risks. Sensitivity logistic regression analysis was used to determine whether observed interactions remained significant by insurance type (privately insured, Medicaid, and uninsured).', 'Patients without medical insurance were more likely to present with metastatic cancer (adjusted odds ratio, 1.60; P < .001), were more likely to not receive definitive treatment (adjusted odds ratio, 1.64; P < .001), and had a higher risk of HNCSM (adjusted hazard ratio, 1.20; P\xa0= .002). Sensitivity analyses showed that when results were stratified by insurance type, significant interactions remained for uninsured patients and patients with Medicaid.\Question: Does health Insurance affect Head and Neck Cancer Treatment Patterns and Outcomes?

SOLUTION:
Uninsured patients and patients with Medicaid are more likely to present with metastatic disease, are more likely to not be treated definitively, and are at a higher risk of HNCSM. The treatment gap between Medicaid and private insurance observed in this study should serve as an immediate policy target for health care reform.