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.

Q: Context: Emphysema, especially in the upper lobes, is frequently observed in association with idiopathic pulmonary fibrosis (IPF). However, the combination of emphysema plus IPF has received little attention.', 'To investigate the additional functional impairment from emphysema in IPF patients.', 'Twenty-one patients (mean age 66 y, 20 men) (Group I) who had both IPF (mean 35% of total lung volume) and emphysema (mean 14% of total lung volume) were compared to a group of 21 subjects who had IPF but no emphysema (Group II). The groups were matched for (among other criteria) the total extent of disease. Pulmonary function tests, Medical Research Council dyspnea score, 6-min walk test, and radiographic extents of both IPF and emphysema were obtained for each patient. The Composite Physiologic Index was calculated. In the total population (n = 42), the independent contributions of IPF and emphysema to several physiologic variables were investigated by using stepwise multiple regression analysis.', 'Despite the limited extent of emphysema, Groups I and II had similar physiologic impairment. Only residual volume and total lung capacity were significantly higher in Group I. According to stepwise multiple regression analysis, the extent of IPF and either the presence or the extent of emphysema in the total population were independent and significant predictors of dyspnea score, 6-min walk test, P(aO2), forced expiratory volume in the first second (FEV(1)), forced vital capacity (FVC), FEV1/FVC, the diffusing capacity of the lung for carbon monoxide, carbon monoxide diffusing capacity adjusted for alveolar volume (gas-transfer coefficient), and residual volume. The Composite Physiologic Index was closely related to the extent of IPF (r = 0.65, p < 0.0001) and to the dyspnea score (rho = 0.59, p < 0.0001).\Question: Does the presence of emphysema further impair physiologic function in patients with idiopathic pulmonary fibrosis?

A: In former smokers with IPF, the presence and the extent of emphysema have a profound influence on physiologic function in terms of both further impairment and confounding effects.
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Q: Context: This study examined the relationship between plasma cholesterol and circulating triiodothyronine and oestradiol in 561 adolescent girls aged 11-17 with eating disorders.', 'Plasma total cholesterol, high-density lipoprotein cholesterol, serum triodothyronine and oestradiol were measured at assessment, and historical weight data were obtained from growth charts provided by the school health services. Cholesterol levels were related to weight change, menstrual status and serum hormones.', 'Plasma total cholesterol levels of >5.0 mmol/L were found in 38% of the 77 girls who were premenarcheal, 32% of the 199 with secondary amenorrhoea and 17% of those who were still menstruating. These cholesterol levels were inversely related to serum oestradiol and triiodothyronine concentrations, but not weight change, in amenorrhoic girls and were positively related to body mass index and inversely related to weight loss and serum triiodothyronine in girls who were still menstruating.\Question: Is plasma cholesterol related to menstrual status in adolescent girls with eating disorders and weight loss?

A: Increased plasma total cholesterol was related to amenorrhoea in adolescent girls with eating disorders and weight loss. Oestrogens appeared to mediate the effect of starvation on cholesterol, most effectively in premenarcheal girls. Re-establishing menstruation is an important goal in the treatment of eating disorders, to avoid dyslipidaemia and the risk of future cardiovascular disease.
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Q: Context: Human skeletal muscles express three major myosin heavy chain (MyHC) isoforms: MyHCIIx (MYH1) in fast type 2B muscle fibers, MyHCIIa (MYH2) in fast type 2A fibers and MyHCI/β-cardiac MyHC (MYH7) in slow type I skeletal fibers and cardiac ventricles. In line with its expression pattern, MYH7 mutations have been reported in association with hypertrophic or dilated cardiomyopathy, skeletal myopathies or a combination of both. We analyzed the clinical and molecular phenotype of two unrelated families of Jewish Moroccan ancestry that presented with apparently autosomal dominant inheritance of progressive Laing-like distal myopathy with non-specific myopathic changes, but uncommon marked contractures and wasting of the neck extensors.', 'Clinical phenotyping, whole exome sequencing and restriction analysis, generation of mutants followed by cell culture transfection and imaging.', 'Using whole exome sequencing we identified in both families two novel heterozygous proline substitutions located in exon 31 of MYH7 within its rod domain: c.4309G>C (p.Ala1437Pro) and c.4301G>C (p.Arg1434Pro). Here we show that the phenotype caused by these mutations includes marked cervical muscle contracture, and report that the severity of the phenotype varies significantly, to the extent of non-penetrance in one of the families. Finally, we provide evidence that both proline substitutions impair myosin self-assembly in non-muscle cells transfected with β-myosin constructs carrying the mutations, but do not prevent incorporation of the mutant molecules into the sarcomere.\Question: Do two novel MYH7 proline substitutions cause Laing Distal Myopathy-like phenotypes with variable expressivity and neck extensor contracture?

A:
This study expands our clinical and molecular knowledge of MYH7 rod mutations causing skeletal myopathies, and underscores the importance of discussing disease penetrance during genetic counseling.
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