Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Context: Although the presence of perineural invasion has been recognized as a poor prognostic factor in extrahepatic cholangiocarcinoma, the molecular mechanisms of perineural invasion in extrahepatic cholangiocarcinoma remain unclear. Nerve growth factor has been reported to be a candidate predictive biomarker of perineural invasion in some cancers.', 'To investigate the impact of intratumoral nerve growth factor expression in resected extrahepatic cholangiocarcinoma on survival.', 'Intratumoral nerve growth factor expression was investigated immunohistochemically in 112 patients with resected extrahepatic cholangiocarcinoma. Associations between nerve growth factor expression and clinicopathological factors were statistically evaluated, and risk factors for poor survival were analyzed using univariate and multivariate analyses.', 'High and low nerve growth factor expression was observed in 62 (55%) and 50 (45%) patients, respectively. For all 112 patients, no significant correlation was found between nerve growth factor expression and presence of perineural invasion (P = 0.942). Moreover, nerve growth factor expression was not associated with recurrence-free survival (P = 0.861) and overall survival (P = 0.973). In multivariate analysis, lymph node metastasis (P = 0.004) was identified as an independent risk factor for early recurrence and the presence of perineural invasion (P = 0.002) and lymph node metastasis (P < 0.001) was identified as independent risk factors for poor survival.
Answer: Intratumoral nerve growth factor expression is not associated with perineural invasion or recurrence-free and overall survival in patients with resected extrahepatic cholangiocarcinoma.
Is nerve Growth Factor Expression Associated with Perineural Invasion in Extrahepatic Cholangiocarcinoma?

Context: The aim of this clinical study were to compare the clinical efficacy of ankaferd blood stopper (ABS) when used in combination with autogenous cortical bone graft (ACB) in the treatment of intrabony periodontal defects.', 'The study was planned as a split-mouth design. Fifteen patients with chronic periodontitis at 30 sites (six men, nine women; 42 ± 7 years) were included. Treatment sites had probing pocket depths (PPD) of ≥ 6 mm and osseous defect depths of ≥ 4 mm as radiographically assessed. Following the initial periodontal therapy, patients were randomly assigned to two treatments in contralateral areas of the dentition: ACB + ABS or ACB alone. At baseline and 6 mo after surgery, clinical parameters of plaque index, gingival index, PPD, clinical attachment level and gingival recession (GR) were recorded. The primary outcome variable was the change in clinical attachment level between baseline and 24 wk after surgery. Gingival crevicular fluid samples were collected immediately before surgery and at 2, 4, 6, 12 and 24 wk after the surgery. Gingival crevicular fluid volume was calculated and vascular endothelial growth factor levels in gingival crevicular fluid were measured.', 'PPD decreased, clinical attachment level improved and gingival index decreased significantly in response to both modes of treatment (p < 0.05). Both treatment modalities resulted in a significant gain in radiographic bone levels compared to baseline (p < 0.05). Intergroup comparisons showed that there was a significantly higher gain in clinical attachment level in the ABS/ACB group compared to ACB group (p < 0.05) with significantly less GR (p < 0.05). Similarly, vascular endothelial growth factor concentration in gingival crevicular fluid was significantly higher in the ABS/ACB group at postoperative weeks 2 and 4 compared to the ACB group (p < 0.01).
Answer: The findings suggest that ABS enhances the soft tissue healing during the periodontal defect fill by the ACB by stimulating angiogenesis and vascular endothelial cell function, prevents GR and thereby increases the clinical attachment gain.
Does ankaferd blood stopper enhance healing after osseous grafting in patients with intrabony periodontal defects?

Context: The present study was undertaken to characterise the viral polypeptide 2 (VP2) gene of parvovirus from domestic cats in India.', 'The faecal samples from diarrhoeic/healthy domestic cats were collected from different geographical regions of India for screening by PCR assay followed by sequence analysis of the VP2 gene.', 'Canine parvovirus (CPV)/feline panleukopenia virus (FPV) infections were found in 12 samples (11.3%) of 106 faecal samples tested. Two new CPV-2a (297Ala and Asn426) and three FPV strains were identified by VP2 gene analysis. Several unique and existing amino acid mutations were found suggesting continuous evolution and emergence of newer variants. The phylogenetic analysis of the CPV sequences revealed that the two new CPV-2a strains from Mumbai (MC8) and Puducherry (P15) were clustered together in a single clade but had evolved independently and were ancestrally related to Chinese CPV-2a isolates. The FPV sequences (T-C-6 and T-C-1) from Thrissur, Kerala, formed a different clade (FPV clade) and were closely related to each other and had an ancestral relationship with an FPV isolate from the USA. Another FPV isolate from Goa (GC1) was positioned in the same clade but had evolved independently.
Answer: Detection of CPV in both diarrhoeic/healthy cats and the occurrence of FPV infection in a vaccinated cat provide new insights into parvovirus infections in cats in India.

Does molecular characterisation of parvoviruses from domestic cats reveal emergence of newer variants in India?