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.

Input: Consider Input: Context: Disruptions to intermyocyte coupling have been implicated in arrhythmogenesis and development of conduction disturbances. At present, understanding of the relationship between the microscopic organization of intercellular coupling and the macroscopic spread of impulse in the normal and diseased heart is largely confined to theoretical analyses.', 'The abundance and arrangement of gap junctions, as well as conduction properties, were assessed in terminal crest preparations isolated from the atria of neonate, weanling, and adult rabbits. We report that the connexin composition of terminal crest was uncomplicated, with Cx43 being the most prominent isoform detectable by Western blotting and immunostaining. Terminal crest myocytes showed little change in total Cx43-gap junction per cell during postnatal growth as assessed by stereology. However, marked non-uniformities emerged in the sarcolemmal distribution of Cx43-gap junctions. Cx43-gap junction area at myocyte termini increased 3.5-fold from birth to adulthood. Correlated with this change in Cx43, impulse propagation velocity parallel to the myofiber axis, as assessed by multi-site optical mapping using voltage-sensitive dye (di-4-ANEPPS), increased 2.4-fold. Conversely, the amount of Cx43-gap junctions on myocyte sides, and the conduction velocity transverse to the myofiber axis, remained relatively invariant during maturation. Hence, the increasing electrical anisotropy of maturing terminal crest was wholly accounted for by increases in conductance velocity along the bundle. This increase in longitudinal conduction velocity was correlated with changes in the sarcolemmal pattern, but not the overall density, of Cx43-gap junctions.
Answer: This study provides the first correlative structure/function analysis of the relationship between the macroscopic conduction of impulse and the microscopic cellular organization of gap junctions in a differentiating cardiac bundle. Confirmation is provided for theoretical predictions which emphasize the importance of the cell-to-cell geometry of coupling in determining the spread and pattern of myocardial activation.

Output: Are the rate and anisotropy of impulse propagation in the postnatal terminal crest correlated with remodeling of Cx43 gap junction pattern?

Input: Consider Input: Context: Observational and clinical studies suggest different responses upon sex hormone replacement therapy in ischaemic heart disease. Few studies, however, have examined the impact of oestrogen receptor-dependent mechanisms on the extent of injury after myocardial infarction (MI). Therefore, we set out to evaluate the effect of oestrogen (E2) replacement on infarct size and remodelling, and the respective role of the oestrogen receptors (ER)alpha and -beta in this process, using ERalpha- and ERbeta-deficient mice.', 'Wild type (WT) (ERalpha(+/+) and ERbeta(+/+)), ERalpha-deficient (ERalpha(-/-)) and ERbeta-deficient (ERbeta(-/-)) mice were ovariectomized and subsequently supplemented with E2 or placebo using subcutaneous 60-day release pellets. MI was induced by left coronary artery ligation. Two weeks following MI, haemodynamic function was assessed and infarct size was determined.', 'There was no significant difference in infarct size between E2- or placebo-treated WT (ERalpha(+/+) and ERbeta(+/+)) mice. Surprisingly, E2 treatment did result in smaller infarct sizes in ERalpha(-/-) mice, but increased the infarct size in ERbeta(-/-) mice. Increase of the left ventricular mass post-MI was significantly larger in the E2-treated ERalpha(-/-) animals compared with placebo-treated animals. E2 treatment also significantly increased post-MI mortality in ERalpha(+/+), ERbeta(+/+) and ERalpha(-/-) animals, but not in ERbeta(-/-) mice.
Answer: Although E2 modulates the infarct size in ERalpha(-/-), it also appears to be responsible for the higher mortality following MI. ERbeta appears to be the receptor involved in the modulating effects of E2 in the infarcted heart.

Output: Does oestrogen modulate cardiac ischaemic remodelling through oestrogen receptor-specific mechanisms?

Input: Consider Input: Context: Our previous work demonstrated altered messenger RNA expression of integrin -5 and -8, using an in silico analysis of publically available data from patients with biliary atresia (BA); however, we were unable to demonstrate statistically significant differences in protein expression because of sample size. In the present study, we repeated the analysis of liver fibrosis and protein expression of the integrins in a larger cohort of patients with BA and compared them with patients undergoing liver biopsy for other diagnoses, with the hypothesis that 1 of the integrins would be differentially expressed.', 'Liver specimens were obtained at 2 collaborating institutions. Samples from infants with BA (n = 23) were compared with samples from those who underwent liver biopsy for neonatal hepatitis (n = 9). All of the specimens were analyzed by 2 pathologists (C.R. and R.A.), who were blinded to the diagnoses. Standard Ishak scoring was performed to evaluate fibrosis and inflammation, and immunohistochemical (IHC) positivity was graded from 0 to 4. Comparisons between the IHC positivity and Ishak scoring for the BA and control groups were performed using the Student t test with P < 0.01 considered significant because of the multiple comparisons. Interobserver variability was assessed by intraclass correlation (ICC).', 'Pooled analysis from specimens from patients with BA showed significantly more fibrosis than controls based on Ishak scores (3.21 1.82 vs 1.17 1.00, P < 0.005). IHC evaluation showed increased integrin 8 protein expression when compared with controls (2.67 0.81 vs 1.72 0.62, P < 0.005); however, there were no significant differences in integrin 5 (1.93 0.84 vs 1.50 0.90, P = 0.23) or integrin 6 (0.85 1.20 vs 0.94 0.85, P = 0.82) expression. These data were confirmed on individual analysis. Interobserver agreement was fair for integrin 5 (ICC 0.52), good for integrin 6 (ICC 0.72), and excellent for integrin 8 (ICC 0.79) and fibrosis (ICC 0.89).
Answer: Our data show that integrin 8, but not integrin 5 or integrin 6, protein expression is increased in liver specimens of patients with BA. These data support the mounting evidence that transforming growth factor- (TGF-) activation is responsible for the fibrosis found in BA. Anti-integrin 8 or more global integrin blocking strategies may be therapeutic options in BA, but further work is clearly needed.
Output: Is integrin -8 , but not -5 or -6 , protein expression increased in livers of children with biliary atresia?