instruction:
Given a passage, 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.
question:
The FAS/FASLG system has been proposed to play a key role in germ cell apoptosis. To elucidate the role of the genetic variants of cell death pathway genes in male infertility, we genotyped the polymorphisms of FAS, FASLG and caspase-8 (CASP8) genes and evaluated their effects on sperm apoptosis and semen quality in infertile men.', 'The genotypes of FAS, FASLG and CASP8 were determined in 620 infertile men. Sperm apoptosis rates were measured by terminal deoxynucleotidyl transferase (Tdt)-mediated dUTP nick end labelling (TUNEL) assay, and the semen quality analysis was performed using computer assisted sperm analysis.', 'We found that polymorphisms of FAS-670A/G (rs1800682: A>G) and CASP8-652 6N ins/del (rs3834129: -/CTTACT) were associated with sperm apoptosis and semen quality. Individuals with FAS-670GG showed low apoptosis rate and decreased sperm concentration, compared with the FAS-670AA genotype. Similarly, in comparison with the CASP8-652 6N ins/ins genotype, the CASP8-652 6N (ins/del+del/del) genotypes also showed significantly decreased sperm apoptosis rate and poor sperm motility. Other polymorphisms investigated did not appear to affect sperm apoptosis and semen quality.
answer:
Are polymorphisms in cell death pathway genes associated with altered sperm apoptosis and poor semen quality?

question:
Class III antiarrhythmic agents exhibit reverse rate-dependent lengthening of the action potential duration (APD). In spite of the several theories developed so far to explain this reverse rate dependency (RRD), its mechanism has not yet been clarified. The aim of the present work was to further elucidate the mechanisms responsible for reverse rate-dependent drug effects.', 'Action potentials were recorded from multicellular canine ventricular preparations and isolated cardiomyocytes, at cycle lengths (CLs) varying from 0.3 to 5 s, using conventional sharp microelectrodes. APD was either modified by applying inward and outward current pulses, or by superfusion of agents known to lengthen and shorten APD. Net membrane current (I(m)) was calculated from action potential waveforms. The hypothesis that RRD may be implicit in the relationship between I(m) and APD was tested by numerical modelling. Both drug-induced lengthening (by veratrine, BAY-K 8644, dofetilide, and BaCl(2)) and shortening (by lidocaine and nicorandil) of action potentials displayed RRD, i.e. changes in APD were greater at longer than at shorter CL. A similar dependency of effect on CL was found when repolarization was modified by injection of inward or outward current pulses. I(m) measured at various points during repolarization was inversely proportional to APD and to CL. Model simulations showed that RRD is expected as a consequence of the non-linearity of the relationship between I(m) and APD.
answer:
Is reverse rate dependency an intrinsic property of canine cardiac preparations?

question:
To describe a novel form of pontocerebellar hypoplasia (PCH) and map its genetic locus.', 'PCH is a heterogeneous group of disorders that are characterized by abnormally small cerebellum and brainstem. Autosomal recessive inheritance has been implied in many cases, but no genetic loci have been mapped to date.', 'The authors studied a consanguineous family from the Sultanate of Oman with three siblings with a novel form of PCH. The authors performed clinical studies and linkage analysis of this pedigree.', 'The clinical features of the affected children include developmental delay, progressive microcephaly with brachycephaly, seizures during the first year of life, hypotonia with hyperreflexia, short stature, and optic atrophy. Imaging studies showed a small pons and cerebellum, prominent sulci and lateral ventricles, and decreased cerebral white matter volume. A lack of dyskinesias distinguishes this pedigree from PCH type 2. Genetic studies of this family revealed evidence of significant linkage to chromosome 7q11-21 (maximum multipoint lod score 3.23).
answer:
Does a novel form of pontocerebellar hypoplasia map to chromosome 7q11-21?