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: Pirfenidone (5 methyl-1-phenyl-2(1H)-pyridone) is a novel anti-fibrotic agent, which has been shown to decrease collagen deposition in a variety of animal models in vivo, and recently in hepatic fibrosis also. At cellular level, we have recently demonstrated that pirfenidone is able to inhibit proliferation of hepatic stellate cells induced by platelet-derived growth factor, as well as collagen type I accumulation and alpha1(I) procollagen mRNA expression.', 'To evaluate if pirfenidone maintains its anti-fibrotic properties also when administered after the induction of hepatic damage and to further investigate the molecular mechanisms leading to the anti-fibrotic effect of pirfenidone.', 'Rats treated with dimethylnitrosamine (10 mg/kg) for 5 weeks received a liquid diet containing 0.5% pirfenidone starting from the third week. Pirfenidone treatment reduced the degree of liver injury, as determined by alanine aminotransferase values and necro-inflammatory score, which was associated with reduced hepatic stellate cells proliferation and collagen deposition. Treatment with dimethylnitrosamine increased transcripts levels for transforming growth factorbeta1, procollagen alpha1(I), tissue inhibitors of metalloproteinase-1 and matrix metalloproteinase-2 by 7-, 7-, 4- and 15-fold, respectively. Pirfenidone administration downregulated elevated levels of those transcripts by 50-60%, and this was associated with a 70% reduction in collagen deposition.\Question: Is the anti-fibrotic effect of pirfenidone in rat liver fibrosis mediated by downregulation of procollagen alpha1 ( I ) , TIMP-1 and MMP-2?

SOLUTION: (1) Pirfenidone is effective also if administered after the induction of the hepatic damage; (2) the anti-fibrotic effect of pirfenidone is mainly due to the reduced expression of profibrogenic procollagen alpha1(I) and TIMP-1, most likely through the downregulation of transforming growth factorbeta1 mRNA, and of matrix metalloproteinase-2, which is mainly implicated in the degradation of the normal extracellular matrix.

PROBLEM: Context: Provocative clinical tests are often performed in the diagnosis of ulnar neuropathy at the elbow (UNE) although the evidence for the usefulness of these tests is limited. The aim of this study was to determine the diagnostic value of provocative clinical tests in the diagnosis of UNE in a relevant spectrum of patients and controls.', "A prospective cohort study was performed in consecutive patients clinically suspected of having UNE. All patients underwent a neurological examination and four commonly used provocative clinical tests (Tinel's test, flexion compression test, palpating for local ulnar nerve tenderness and nerve thickening). Subsequently, in all patients a reference standard test comprising electrophysiological studies and neurosonography was independently assessed.", "192 eligible patients completed the study protocol. UNE was diagnosed in 137 and an alternative diagnosis was made in 55 patients. The sensitivity, specificity, and positive and negative predictive values were as follows: Tinel's test 62%, 53%, 77% and 30%; flexion compression test 61%, 40%, 72% and 29%; palpating for nerve thickening 28%, 87%, 84% and 33%; and palpating for nerve tenderness 32%, 80%, 80% and 32%. Logistic regression and receiver operating characteristic curves showed that the added value of one or more provocative tests over routine clinical examination is minimal.\Question: Is the diagnostic value of provocative clinical tests in ulnar neuropathy at the elbow marginal?

SOLUTION: The diagnostic value of provocative clinical tests in UNE is poor.

PROBLEM: Context: To examine the relationships between study quality, author prestige, journal impact factors, and citation rates of trials and to examine whether journal impact factors mediated the relationships between study quality and author prestige on citation rates.', 'We used bibliometric data from 128 controlled trials included in a recent meta-analysis on brief alcohol interventions for adolescents and young adults. We obtained the number of citations from ISI Web of Knowledge and Google Scholar; journal impact factors were obtained from ISI Web of Knowledge. Linear regression models were used to examine the direct and indirect effects of interest.', 'The results indicated that studies were published in journals with higher impact factors when first authors had higher h-indices and studies were funded, but this was largely because those studies were of higher quality. Studies were cited more frequently when first authors had higher h-indices and studies were funded, even after adjusting for study quality proxies. The observed associations between study quality and author prestige on citation rates were also partly mediated through journal impact factors.\Question: Are brief alcohol intervention trials conducted by higher prestige authors and published in higher impact factor journals cited more frequently?

SOLUTION:
We conclude that studies conducted by more established authors and reported in more prestigious journal outlets are more likely to be cited by other scholars, even after controlling for various proxies of study quality.