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.

[Q]: Intracellular pathogens have developed elaborate strategies for silent infection of preferred host cells. Chlamydia pneumoniae is a common pathogen in acute infections of the respiratory tract (e.g. pneumonia) and associated with chronic lung sequelae in adults and children. Within the lung, alveolar macrophages and polymorph nuclear neutrophils (PMN) are the first line of defense against bacteria, but also preferred host phagocytes of chlamydiae.', 'We could show that C. pneumoniae easily infect and hide inside neutrophil granulocytes until these cells become apoptotic and are subsequently taken up by macrophages. C. pneumoniae infection of macrophages via apoptotic PMN results in enhanced replicative activity of chlamydiae when compared to direct infection of macrophages, which results in persistence of the pathogen. Inhibition of the apoptotic recognition of C. pneumoniae infected PMN using PS- masking Annexin A5 significantly lowered the transmission of chlamydial infection to macrophages. Transfer of apoptotic C. pneumoniae infected PMN to macrophages resulted in an increased TGF-ss production, whereas direct infection of macrophages with chlamydiae was characterized by an enhanced TNF-alpha response.
[A]: Does chlamydia pneumoniae hide inside apoptotic neutrophils to silently infect and propagate in macrophages?


[Q]: To determine whether activin A concentrations are altered in chronic fetal hypoxemia and intrauterine fetal growth restriction (IUGR).', 'In vivo animal experimental model.', 'Department of Physiology, Monash University.', 'Chronically catherised fetal sheep in late pregnancy.', 'Chronic fetal hypoxia and IUGR were experimentally induced by single umbilical artery ligation (SUAL) in catheterised fetal sheep. Maternal and fetal blood samples and amniotic fluid (AF) samples were collected during surgery and thereafter on alternate days, until the time of delivery for analyte measurement. Fetal blood gas parameters were measured daily.', 'Plasma and AF was used to analyse activin A, prostaglandin E2 (PGE2) and cortisol and fetal blood gas analysis was undertaken in whole blood.', 'SUAL produced asymmetric IUGR and non-acidaemic chronic fetal hypoxia and resulted in preterm labour (129 [3] days). AF activin A concentrations were 10-fold higher in the SUAL group than in controls whereas levels in the fetal and maternal circulations were similar between groups.
[A]: Does chronic fetal hypoxia increase activin A concentrations in the late-pregnant sheep?


[Q]: Adults and children affected by human immunodeficiency virus type-1 (HIV-1) infection show bone demineralization. Little is known about skeletal status using a quantitative high-frequency ultrasound (QUS) technique in these patients.', 'To evaluate the bone quality and assess the role of the IGF system in the bone metabolism and skeletal status of HIV-1 perinatally infected children.', 'Serum free and total IGF-I, IGFBP-3, serum osteocalcin level, urinary deoxypyridinoline concentration, spontaneous interleukin-6 (IL-6) release and broadband ultrasound attenuation (BUA) were evaluated in 44 prepubertal children who had perinatal HIV-1 infection. The patients were divided into two groups depending on the severity of their clinical condition: group 1 (23 children with no or mild clinical symptoms, mean age 8.0 +/- 2.9 years) and group 2 (21 children with severe clinical symptoms, mean age 8.58 +/- 2.47 years). Fifty-five healthy age- and sex-matched controls were analysed for comparison.', 'Compared with group 1 and the controls, group 2 patients showed a significantly reduced BUA Z-score (P < 0.001), and significantly reduced concentrations of serum osteocalcin (P < 0.001) and urinary deoxypyridinoline (P < 0.001 and P < 0.05, respectively). Group 2 patients also showed significantly reduced serum free IGF-I (P < 0.001) and total IGF-I (P < 0.05) levels compared with the controls, but not with group 1. No statistically significant differences were found between the three groups with regard to IGFBP-3. Group 2 patients showed significantly higher spontaneous IL-6 release than group 1 patients and controls (P < 0.001). BUA Z-scores displayed a significant correlation with free IGF-I in group 2 (r = 0.96; P < 0.001), group 1 (r = 0.56; P = 0.005) and controls (r = 0.50; P < 0.001).
[A]:
Is changed bone status in human immunodeficiency virus type 1 ( HIV-1 ) perinatally infected children related to low serum free IGF-I?