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 aim of this study was to investigate the antiproliferative and cytotoxic effects of a newly synthesized molecule named paracetamol acetohydroxamic acid (PaCaHa) on human neoplastic cell lines.', 'A549, CRL 2923, HeLa, and ARPE were treated with various concentrations of PaCaHa and DMSO (vehicle control). The cytotoxic/cytostatic effects of PaCaHa were determined after a 24-h incubation period and compared to the DMSO control. The cytotoxic and antiproliferative effects were determined by the trypan blue dye exclusion and MTT methods.', 'A higher susceptibility to PaCaHA was found in CRL 2923 and HeLa cells, while A549 and ARPE cells were less responsive to PaCaHa. The percent of cytotoxicity resulting from 400 g/mL of PaCaHa were >90 for CRL-2923 and HeLa, 68 for A549, and 64 for ARPE cells. The cytotoxic difference between CRL-2923/HeLa and ARPE/A549 cells was significant (P < 0.05).\Question: Does paCaHa inhibit proliferation of human cancer cells in vitro?

SOLUTION: PaCaHa showed dose dependent cytotoxic and antiproliferative effects on three distinct human cancer cell lines. The differential effect of PaCaHa on different cancer cell lines suggests that PaCaHa could have a potential antitumor effect on specific cancer types. These results support further comprehensive studies on PaCaHa and its derivatives.

PROBLEM: Context: The cyclooxygenase-2 (cox-2) pathway is now recognized to be important in human cancer development and progression. The gene for cox-2 carries a common single nucleotide polymorphism, T8473C, located within a potential functional region in the 3'-UTR of cox-2 gene was identified. We have investigated the frequencies of cox-2 genotypes in Tunisian population to determine whether that polymorphism was associated with the risk of nasopharyngeal carcinoma (NPC) in Tunisian population.", 'One hundred and eighty-nine NPC patients were compared to 237 healthy controls.', 'The cox-2 T8473C polymorphism was significantly associated with NPC (P=0.031). The CC-genotype and C allele were more frequent in control compared to patients group [CC: OR=0.37; P=0.013; 95% CI: 0.17-0.81; C: OR=0.72; P=0.032; 95% CI: 0.53-0.97]. Multivariate logistic regression analyses revealed that the CC-genotype was associated with a significantly decreased risk of NPC (P=0.013). Tumor sizes, histologic grade, presence of primary lymph node metastases, age or sex were not associated with cox-2 genotypes.\Question: Does the CC-genotype of the cyclooxygenase-2 gene associate with decreased risk of nasopharyngeal carcinoma in a Tunisian population?

SOLUTION: We conclude that the CC-genotype and C allele of cox-2 T8473C gene polymorphism are associated with decreased risk of nasopharyngeal carcinoma in a Tunisian population.

PROBLEM: Context: The aim of this study is to assess the usefulness of perfusion computer tomography (pCT) in prostate cancer (PCa) diagnostics.', '94 patients with biopsy-proven PCa were enrolled in the study. Dynamic pCT of the prostate gland was performed for 50 seconds after an intravenous injection of contrast medium. Blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) were computed in the suspected PCa area and in normal prostatic tissue.', 'PCa was visible in pCT in 90 of the 94 examined patients as a focal peripheral CT enhancement. When PCa was located in the peripheral zone (PZ), it was visible on perfusion maps, mostly showing an early peak followed by wash-out. The average values of all perfusion parameters were higher for tumour than for normal prostate tissue (p < 0.000). BV and BF were dependent on tumour grade expressed by the Gleason score (GS). All PCa cases were divided into groups, according to histological grade, as low (GS 6), medium (GS = 7), and high (GS > 7). In high-grade PCa, the mean BF value was significantly higher (p = 0.001) than the mean value of BF low- and medium-grade PCa (p = 0.011). Similar results were obtained regarding the mean values of BV; the more aggressive the cancer grade, the higher the mean BV value (p = 0.04).\Question: Is perfusion CT a valuable diagnostic method for prostate cancer : a prospective study of 94 patients?

SOLUTION:
CT quantitative perfusion imaging allows PCa to be distinguished from normal prostate tissue. The highest values for BF and BV were observed in the most aggressive PCa grade.