In this task, you are given an abstract of article. Your task is to generate title for this article. Preferred titles are under thirty words.
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Question: IMPORTANCE There is currently no consensus for the screening and treatment of patent ductus arteriosus (PDA) in extremely preterm infants. Less pharmacological closure and more supportive management have been observed without evidence to support these changes.
OBJECTIVE To evaluate the association between early screening echocardiography for PDA and in-hospital mortality.
DESIGN, SETTING, AND PARTICIPANTS Comparison of screened and not screened preterm infants enrolled in the EPIPAGE 2 national prospective population-based cohort study that included all preterm infants born at less than 29 weeks of gestation and hospitalized in 68 neonatal intensive care units in France from April through December 2011. Two main analyses were performed to adjust for potential selection bias, one using propensity score matching and one using neonatal unit preference for early screening echocardiography as an instrumental variable. EXPOSURES Early screening echocardiography before day 3 of life.
MAIN OUTCOMES AND MEASURES The primary outcome was death between day 3 and discharge. The secondary outcomes were major neonatal morbidities (pulmonary hemorrhage, severe bronchopulmonary dysplasia, severe cerebral lesions, and necrotizing enterocolitis).
RESULTS Among the 1513 preterm infants with data available to determine exposure, 847 were screened for PDA and 666 were not; 605 infants from each group could be paired. Exposed infants were treated for PDA more frequently during their hospitalization than nonexposed infants (55.1% vs 43.1%; odds ratio [OR], 1.62 [95% CI, 1.31 to 2.00]; absolute risk reduction [ARR] in events per 100 infants, -12.0 [95% CI, -17.3 to -6.7). Exposed infants had a lower hospital death rate (14.2% vs 18.5% ; OR, 0.73 [95% CI, 0.54 to 0.98]; ARR, 4.3 [95% CI, 0.3 to 8.3]) and a lower rate of pulmonary hemorrhage (5.6% vs 8.9%; OR, 0.60 [95% CI, 0.38 to 0.95]; ARR, 3.3 [95% CI, 0.4 to 6.3]). No differences in rates of necrotizing enterocolitis, severe bronchopulmonary dysplasia, or severe cerebral lesions were observed. In the overall cohort, instrumental variable analysis yielded an adjusted OR for in-hospital mortality of 0.62 [95% CI, 0.37 to 1.04].
CONCLUSIONS AND RELEVANCE In this national population-based cohort of extremely preterm infants, screening echocardiography before day 3 of life was associated with lower in-hospital mortality and likelihood of pulmonary hemorrhage but not with differences in necrotizing enterocolitis, severe bronchopulmonary dysplasia, or severe cerebral lesions. However, results of the instrumental variable analysis leave some ambiguity in the interpretation, and longer-term evaluation is needed to provide clarity.

Answer: Association Between Early Screening for Patent Ductus Arteriosus and In-Hospital Mortality Among Extremely Preterm Infants.

Question: Male infertility is a long-standing enigma of significant medical concern. The integrity of sperm chromatin is a clinical indicator of male fertility and in vitro fertilization potential: chromosome aneuploidy and DNA decondensation or damage are correlated with reproductive failure. Identifying conserved proteins important for sperm chromatin structure and packaging can reveal universal causes of infertility. Here we combine proteomics, cytology and functional analysis in Caenorhabditis elegans to identify spermatogenic chromatin-associated proteins that are important for fertility. Our strategy employed multiple steps: purification of chromatin from comparable meiotic cell types, namely those undergoing spermatogenesis or oogenesis; proteomic analysis by multidimensional protein identification technology (MudPIT) of factors that co-purify with chromatin; prioritization of sperm proteins based on abundance; and subtraction of common proteins to eliminate general chromatin and meiotic factors. Our approach reduced 1,099 proteins co-purified with spermatogenic chromatin, currently the most extensive catalogue, to 132 proteins for functional analysis. Reduction of gene function through RNA interference coupled with protein localization studies revealed conserved spermatogenesis-specific proteins vital for DNA compaction, chromosome segregation, and fertility. Unexpected roles in spermatogenesis were also detected for factors involved in other processes. Our strategy to find fertility factors conserved from C. elegans to mammals achieved its goal: of mouse gene knockouts corresponding to nematode proteins, 37% (7/19) cause male sterility. Our list therefore provides significant opportunity to identify causes of male infertility and targets for male contraceptives.

Answer: Sperm chromatin proteomics identifies evolutionarily conserved fertility factors

Question: The cellular constituents forming the haematopoietic stem cell (HSC) niche in the bone marrow are unclear, with studies implicating osteoblasts, endothelial and perivascular cells. Here we demonstrate that mesenchymal stem cells (MSCs), identified using nestin expression, constitute an essential HSC niche component. Nestin+ MSCs contain all the bone-marrow colony-forming-unit fibroblastic activity and can be propagated as non-adherent 'mesenspheres' that can self-renew and expand in serial transplantations. Nestin+ MSCs are spatially associated with HSCs and adrenergic nerve fibres, and highly express HSC maintenance genes. These genes, and others triggering osteoblastic differentiation, are selectively downregulated during enforced HSC mobilization or 3 adrenoreceptor activation. Whereas parathormone administration doubles the number of bone marrow nestin+ cells and favours their osteoblastic differentiation, in vivo nestin+ cell depletion rapidly reduces HSC content in the bone marrow. Purified HSCs home near nestin+ MSCs in the bone marrow of lethally irradiated mice, whereas in vivo nestin+ cell depletion significantly reduces bone marrow homing of haematopoietic progenitors. These results uncover an unprecedented partnership between two distinct somatic stem-cell types and are indicative of a unique niche in the bone marrow made of heterotypic stem-cell pairs.

Answer:
Mesenchymal and haematopoietic stem cells form a unique bone marrow niche