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: The present study was designed to investigate whether H2S can protect testicular germ cells against heat exposure induced injury and the underlying mechanisms.', 'It was found that all three H2S generating enzymes, cystathionine -synthase (CBS), cystathionine -lysase (CSE), and 3-mercaptopyruvate sulfurtransferase (3 MST), were expressed in mouse testicular tissue. Three episodes of heat exposure (42 C, 30 min/day, 3 days) significantly decreased endogenous H2S production and down-regulated the expression of CBS and CSE in testes. In primary cultured testicular germ cells, exogenous application of NaHS (an H2S donor) attenuated heat stress (42 C, 30 min) induced cell death and apoptosis. This was mediated by the inhibitory effects of H2S on cytochrome C release and the ratio of the Bax/Bcl-2. NaHS also improved mitochondrial function by decreasing oxygen consumption and increasing ATP production. NaHS treatment also stimulated SOD activity and reduced ROS production.\Question: Does hydrogen sulfide protect testicular germ cells against heat-induced injury?

SOLUTION: Our results revealed both physiological and pharmacological roles of H2S in testicular germ cells. Exogenous application of H2S may protect germ cells by preservation of mitochondrial function and stimulation of anti-oxidant activity.

PROBLEM: Context: Staphylococcus aureus sepsis is associated with significant myocardial dysfunction. Toll-like receptor 2 (TLR2) mediates the inflammatory response to S aureus and may trigger an innate immune response in the heart. We hypothesized that a TLR2 deficiency would attenuate S aureus-induced cardiac proinflammatory mediator production and the development of cardiac dysfunction.', 'Wild-type and TLR2-deficient (TLR2D) mice were studied. S aureus challenge significantly increased tumor necrosis factor, interleukin-1beta, and nitric oxide expression in hearts of wild-type mice. This response was significantly blunted in TLR2D mice. Hearts from TLR2D mice had impaired S aureus-induced activation of interleukin-1 receptor-associated kinase, c-Jun NH2 terminal kinase, nuclear factor-kappaB, and activator protein-1. Moreover, hearts from TLR2D mice were protected against S aureus-induced contractile dysfunction.\Question: Does toll-like receptor 2 mediate Staphylococcus aureus-induced myocardial dysfunction and cytokine production in the heart?

SOLUTION: These results show for the first time that TLR2 signaling contributes to the loss of myocardial contractility and cytokine production in the heart during S aureus sepsis.

PROBLEM: Context: Guidelines recommend upper endoscopic screening of cirrhotic patients for gastroesophageal varices. Cirrhosis is not always distinguishable from chronic hepatitis.', 'To identify low-risk patients who can be spared upper endoscopy irrespective of a diagnosis of cirrhosis.', 'We evaluated 13 nonendoscopic variables as predictors of esophagogastric varices in 254 patients with hepatitis B or hepatitis C-related chronic liver disease who underwent upper endoscopy.', 'Any size varices occurred in 30.3% (77/254), and large varices in 12.2% of patients (31/254). Age >50 years [odds ratio (OR): 11.29; 95% confidence interval (CI): 2.33-54.67], platelet count <150,000/mmc (OR: 4.40; 95% CI: 1.85-10.45), albumin <3.6 g/dL (OR: 2.99; 95% CI: 1.31-6.79), and aspartate aminotransferase/alanine aminotransferase ratio >1 (OR: 2.83; 95% CI: 1.26-6.34) independently predicted varices by logistic regression. Using a score based on age >50 years, platelets <150,000/mmc, and aspartate aminotransferase/alanine aminotransferase ratio >1 (1 point/predictor), only 3.2% of patients with a score <2 had varices, all small.\Question: Does a simple noninvasive score predict gastroesophageal varices in patients with chronic viral hepatitis?

SOLUTION:
Patients with chronic viral hepatitis and a score <2 need not undergo upper endoscopy, as they are unlikely to have large varices. Because about 50% of our patients had this score, 50% of upper endoscopies may be safely avoided.