IntroductionInterventions directed toward mothers before and during pregnancy and childbirth may help reduce preterm births and stillbirths. Survival of preterm newborns may also be improved with interventions given during these times or soon after birth. This comprehensive review assesses existing interventions for low- and middle-income countries (LMICs).MethodsApproximately 2,000 intervention studies were systematically evaluated through December 31, 2008. They addressed preterm birth or low birth weight; stillbirth or perinatal mortality; and management of preterm newborns. Out of 82 identified interventions, 49 were relevant to LMICs and had reasonable amounts of evidence, and therefore selected for in-depth reviews. Each was classified and assessed by the quality of available evidence and its potential to treat or prevent preterm birth and stillbirth. Impacts on other maternal, fetal, newborn or child health outcomes were also considered. Assessments were based on an adaptation of the Grades of Recommendation Assessment, Development and Evaluation criteria.ResultsMost interventions require additional research to improve the quality of evidence. Others had little evidence of benefit and should be discontinued. The following are supported by moderate- to high-quality evidence and strongly recommended for LMICs:• Two interventions prevent preterm births—smoking cessation and progesterone• Eight interventions prevent stillbirths—balanced protein energy supplementation, screening and treatment of syphilis, intermittant presumptive treatment for malaria during pregnancy, insecticide-treated mosquito nets, birth preparedness, emergency obstetric care, cesarean section for breech presentation, and elective induction for post-term delivery• Eleven interventions improve survival of preterm newborns—prophylactic steroids in preterm labor, antibiotics for PROM, vitamin K supplementation at delivery, case management of neonatal sepsis and pneumonia, delayed cord clamping, room air (vs. 100% oxygen) for resuscitation, hospital-based kangaroo mother care, early breastfeeding, thermal care, and surfactant therapy and application of continued distending pressure to the lungs for respiratory distress syndromeConclusionThe research paradigm for discovery science and intervention development must be balanced to address prevention as well as improve morbidity and mortality in all settings. This review also reveals significant gaps in current knowledge of interventions spanning the continuum of maternal and fetal outcomes, and the critical need to generate further high-quality evidence for promising interventions.
Antifreeze proteins (AFPs) are extremely efficient at inhibiting ice recrystallization in frozen solutions. Knight and Duman [Knight, C. A. & Duman, J. G. (1986) Cryobiology 23, [256][257][258][259][260][261][262][263] have proposed that this may be an important function ofthe proteins in freeze-tolerant organisms. We have tested this proposal in vitro by characterizing the influence of AFP on the recovery of cryopreserved cells, which often can survive cooling and yet subsequently be damaged by ice crystal growth during warming. Relatively low concentrations (e.g., 5-150 ,ug/ml) of winter flounder (Pseudopleuronectes americanus) AFP enhance survival of red blood cells cryopreserved in hydroxyethyl starch solutions. This effect is most apparent in samples warmed at suboptimal rates, i.e., where ice recrystallization would be exaggerated. Cryomicroscopy demonstrates that AFP inhibits ice recrystallization in the extracellular regions during the latter stages of the warming cycle. AFP concentrations that enhance survival of red cells confer partial inhibition of recrystallization. Relatively high concentrations of AFP (e.g., 1.54 mg/ml) are much more effective at inhibiting extracellular recrystallization. However, extensive growth of ice around the cell, and concomitant cell damage, is noted. The mechanism for this AFP-induced ice growth is unknown. We propose that there is a delicate balance between AFP-induced enhancement of cell preservation and AFP-induced enhancement of cell damage and that this balance hinges on the degrees of inhibition of ice recrystallization and ofpreferential growth of ice around the cells. We conclude that, under appropriate conditions, one of the proposed functions of AFPs in nature can be emulated, and perhaps have application, in cryopreservation of materials of biomedical interest.Research to date has suggested two distinctly different major functions for antifreeze proteins (AFPs) in nature. First, in certain teleost fish from polar and north temperate regions and in some overwintering insects, the proteins noncolligatively lower the freezing point of the body fluids by at least 1°C, without significantly affecting the melting point (1-7). The proteins appear to function solely as antifreezes, since exposure to temperatures that lead to ice formation results in the death of the organism (3,4,7,8).AFPs are also produced by some species of insects, centipedes, intertidal molluscs, and plants that can survive freeze-thawing (4, 7, 9-11). AFPs isolated from both fish and insects, even at concentrations of <1 A&g/ml, are extremely effective at inhibiting recrystallization of ice (11-13). Recrystallization can occur as frozen samples are warmed to temperatures at which there is sufficient kinetic energy for the migration of water molecules from one ice crystal to another and is, thus, very rapid near the melting point (11). As explained by Knight and Duman (11), this process occurs, in part, because the overall interfacial surface area and free energy of the system are reduced ...
Recently, next-generation sequencing has been introduced as a promising, new platform for assessing the copy number of transcripts, while the existing microarray technology is considered less reliable for absolute, quantitative expression measurements. Nonetheless, so far, results from the two technologies have only been compared based on biological data, leading to the conclusion that, although they are somewhat correlated, expression values differ significantly. Here, we use synthetic RNA samples, resembling human microRNA samples, to find that microarray expression measures actually correlate better with sample RNA content than expression measures obtained from sequencing data. In addition, microarrays appear highly sensitive and perform equivalently to next-generation sequencing in terms of reproducibility and relative ratio quantification.
Mitogen-activated protein (MAP) kinases play a pivotal role in the macrophages in the production of proinflammatory cytokines triggered by lipopolysaccharides. However, their function in the responses of macrophages to Gram-positive bacteria is poorly understood. Even less is known about the attenuation of MAP kinase signaling in macrophages exposed to Gram-positive bacteria. In the present study, we have investigated the regulation of MAP kinases and the role of MAP kinase phosphatase (MKP)-1 in the production of pro-inflammatory cytokines using murine RAW264.7 and primary peritoneal macrophages after peptidoglycan stimulation. Treatment of macrophages with peptidoglycan resulted in a transient activation of JNK, p38, and extracellular signal-regulated kinase. Most interestingly, MKP-1 expression was potently induced by peptidoglycan, and this induction was concurrent with MAP kinase dephosphorylation. Triptolide, a diterpenoid triepoxide, potently blocked the induction of MKP-1 by peptidoglycan and prolonged the activation of JNK and p38. Overexpression of MKP-1 substantially attenuated the production of tumor necrosis factor (TNF)-alpha induced by peptidoglycan, whereas knockdown of MKP-1 by small interfering RNA substantially increased the production of both TNF-alpha and interleukin-1 beta. Finally, we found that in primary murine peritoneal macrophages, MKP-1 induction following peptidoglycan stimulation also coincided with inactivation of JNK and p38. Blockade of MKP-1 induction resulted in a sustained activation of both JNK and p38 in primary macrophages. Our results reveal that MKP-1 critically regulates the expression of TNF-alpha and interleukin-1 beta in RAW264.7 cells and further suggest a central role for this phosphatase in controlling the inflammatory responses of primary macrophages to Gram-positive bacterial infection.
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