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.

[Q]: Context: Matrix metalloprotease-2 (MMP-2) and matrix metalloprotease-9 (MMP-9) play a key role in tissue remodelling after processes such as joint destruction in rheumatoid arthritis. Their expression may reflect the disease activity and they could therefore represent a useful marker to assess the efficacy of therapy. In this study MMP-2 and MMP-9 serum were evaluated in patients with chronic arthritis during therapy with the anti-TNFalpha mAb, infliximab.', 'Fifty patients with chronic arthritis, 26 with rheumatoid arthritis and 24 with undifferentiated chronic arthritis, were recruited and treated with infliximab (3 mg/kg). Serum concentrations of MMP-2 and MMP-9 were serially measured by gelatine zymography at baseline and after two and fourteen weeks of infliximab therapy. DAS-28 and ACR response criteria were applied to assess disease activity and clinical improvement. Twenty-four healthy donors were included in the study as controls.', 'Although therapy with infliximab induced a statistically significant reduction of the DAS-28 score and improvement of the ACR clinical response, MMP-2 and MMP-9 serum concentrations were not modulated during therapy with infliximab.\Question: Does infliximab therapy modify MMP-2 and MMP-9 serum concentrations in chronic arthritis?
[A]: Our study provides further evidence that blocking TNFalpha by infliximab is a powerful tool in the management of chronic arthritis. Nevertheless, infliximab does not seem to be able to modify the serum expression of MMP-2 and MMP-9, probably because modification of these enzymes is restricted to the site of joint inflammation and serum detection can not truly mirror the local situation. Additional soluble factors correlating with joint damage should be investigated as possible markers for monitoring anti-TNFalpha therapy.


[Q]: Context: Stem cell factor (SCF) has well-known proliferative effects on hematopoietic cells. SCF also has effects on differentiation and proliferation in other cell types. Interleukin-6 (IL-6) and tumor necrosis factor (TNF)-alpha have proliferative effects in the liver. Recent studies in our laboratory have linked SCF's hepatoproliferative actions to those of IL-6, demonstrating that IL-6-induced hepatocyte proliferation depends, at least in part, on SCF. We now hypothesize that TNF-alpha's hepatoproliferative effects are also dependent on SCF.", 'In vitro studies using primary mouse hepatocytes show that SCF is induced by TNF-alpha; anti-SCF antibody treatment in this system inhibits TNF-alpha-induced hepatocyte proliferation, suggesting that TNF-alpha-induced hepatocyte proliferation is also SCF dependent. Additional in vivo experiments were performed in which wild type and/or TNF-alpha receptor-1 knockout mice (TNFR1(-/-)) were subjected to 70% hepatectomy or sham laparotomy. TNFR1(-/-) mice are known to have delayed hepatic regeneration after partial hepatectomy. Initial experiments demonstrated that the SCF receptor, c-kit, is upregulated after partial hepatectomy in wild-type mice, further emphasizing the importance of this system in the restoration of hepatic mass. SCF administration to TNFR1(-/-) mice in the context of partial hepatectomy restores hepatocyte proliferation to normal. Further, SCF administration to TNFR1(-/-) mice before hepatectomy increases phosphotyrosine signal transducer and activator (p-stat-3) levels, suggesting that SCF-induced increases in hepatocyte proliferation may also be stat-3 mediated.\Question: Are stem cell factor and its receptor , c-kit , important for hepatocyte proliferation in wild-type and tumor necrosis factor receptor-1 knockout mice after 70 % hepatectomy?
[A]: These data suggest that TNF-alpha-induced hepatocyte proliferation depends, at least in part, on SCF and that SCF and its receptor, c-kit, are important for the liver's regenerative processes.


[Q]: Context: Malignant melanoma risk factors have been studied in different geographical area populations. However, no study has focused on risk factors which are more frequently associated to the over 60's age group.", 'A case-control study was performed that included 160 patients age > or = 60 years diagnosed of cutaneous melanoma and 318 controls matched for age and sex. Both groups were assessed, by personal interview and physical examination, for different phenotype characteristics (hair and eye color, phototype), the presence of other cutaneous lesions (solar lentigines, actinic keratoses and nevi), degree and type of solar exposure and personal and family past history of cutaneous or non-cutaneous cancer. Differences were evaluated by contingency tables and univariate and multivariate logistic regression.', 'Of 17 factors, those risk factors with a strong effect on the development of melanoma in the elderly were: fair eyes, severe sunburns, years of occupational sun exposure, smoking, > 50 melanocytic nevi and personal history of NMSC and other non-cutaneous neoplasias.\Question: Are smoking , sun exposure , number of nevi and previous neoplasias risk factors for melanoma in older patients ( 60 years and over )?
[A]:
Tobacco smoking is an independent risk factor for cutaneous melanoma in the elderly. Intense (both acute and chronic) sun exposure and constitutional features, such as tumor susceptibility (NMSC, non-cutaneous neoplasias, and multiple nevi) are also associated with melanoma risk. All these factors should help to better design educational campaigns in older people.