14 research outputs found
AMP-activated protein kinase:a cellular energy sensor that comes in twelve flavours
The AMPâactivated protein kinase (AMPK) is a sensor of cellular energy status that is expressed in essentially all eukaryotic cells, suggesting that it arose during early eukaryotic evolution. It occurs universally as heterotrimeric complexes containing catalytic α subunits and regulatory ÎČ and Îł subunits. Although Drosophila melanogaster contains single genes encoding each subunit, in mammals, each subunit exists as multiple isoforms encoded by distinct genes, giving rise to up to 12 heterotrimeric combinations. The multiple isoforms of each subunit are 2Râohnologues generated by the two rounds of whole genome duplication that occurred at the evolutionary origin of the vertebrates. Although the differential roles of these isoform combinations remain only partly understood, there are indications that they may have different subcellular locations, different inputs and outputs, and different functions. The multiple isoforms are of particular interest with respect to the roles of AMPK in cancer because the genes encoding some isoforms, such as PRKAA1 and PRKAB2 (encoding α1 and ÎČ2), are quite frequently amplified in tumour cells, whereas the genes encoding others, such as PRKAA2 (encoding α2), tend to be mutated, which, in some but not all cases, may result in a loss of function. Thus, although AMPK acts downstream of the tumour suppressor liver kinase B1, and some of its isoform combinations may act as tumour suppressors that restrain the growth and proliferation of tumour cells, other isoform combinations may paradoxically act as oncogenes, perhaps by aiding the survival of tumour cells undergoing environmental stresses such as hypoxia or nutrient deprivation
Comparison of two PCR methods for detection of Leptospira interrogans in formalin-fixed and paraffin-embedded tissues
Global respiratory syncytial virusârelated infant community deaths
Background
Respiratory syncytial virus (RSV) is a leading cause of pediatric death, with >99% of mortality occurring in low- and lower middle-income countries. At least half of RSV-related deaths are estimated to occur in the community, but clinical characteristics of this group of children remain poorly characterized.
Methods
The RSV Global Online Mortality Database (RSV GOLD), a global registry of under-5 children who have died with RSV-related illness, describes clinical characteristics of children dying of RSV through global data sharing. RSV GOLD acts as a collaborative platform for global deaths, including community mortality studies described in this supplement. We aimed to compare the age distribution of infant deaths <6 months occurring in the community with in-hospital.
Results
We studied 829 RSV-related deaths <1 year of age from 38 developing countries, including 166 community deaths from 12 countries. There were 629 deaths that occurred <6 months, of which 156 (25%) occurred in the community. Among infants who died before 6 months of age, median age at death in the community (1.5 months; IQR: 0.8â3.3) was lower than in-hospital (2.4 months; IQR: 1.5â4.0; Pâ
<â
.0001). The proportion of neonatal deaths was higher in the community (29%, 46/156) than in-hospital (12%, 57/473, Pâ
<â
0.0001).
Conclusions
We observed that children in the community die at a younger age. We expect that maternal vaccination or immunoprophylaxis against RSV will have a larger impact on RSV-related mortality in the community than in-hospital. This case series of RSV-related community deaths, made possible through global data sharing, allowed us to assess the potential impact of future RSV vaccines
Essential mixed cryoglobulinemia, type II: a manifestation of a low-grade malignant lymphoma? Clinical-morphological study of 12 cases with special reference to immunohistochemical findings in liver frozen sections.
Comparison of Ti(C,N)-based cermets processed by hot-pressing sintering and conventional pressureless sintering
Vertical Integration and Technology: Theory and Evidence
This paper investigates the determinants of vertical integration. We first derive annumber of predictions regarding the relationship between technology intensity and vertical integration from a simple incomplete contracts model. Then, we investigate these predictions using plant-level data for the UK manufacturing sector. Most importantly, and consistent with theory, we find that the technology intensities of downstream (producer) and upstream (supplier) industries have opposite effects on the likelihood of vertical integration. Also consistent with theory, both these effects are stronger when the supplying industry accounts for a large fraction of the producerâs costs. These results are generally robust and hold with alternative measures of technology intensity, with alternative estimation strategies, and with or without controlling for a number ofnfirm and industry-level characteristics
Vertical Integration and Technology: Theory and Evidence
We study the determinants of vertical integration. We first derive a number of predictions regarding the relationship between technology intensity and vertical integration from a simple incomplete contracts model. Then, we investigate these predictions using plant-level data for the UK manufacturing sector. Most importantly, and consistent with the theoretical predictions, we find that the technology intensity of downstream (producer) industries is positively correlated with the likelihood of integration whereas the intensity of upstream (supplier) industries is negatively correlated with it. Also consistent with theory, both correlations are stronger when the supplying industry accounts for a large fraction of the producer's costs. These results are generally robust and hold with alternative measures of technology intensity, with alternative estimation strategies, and with or without controlling for a number of firm- and industry-level characteristics.Economic and Social Research Council (Great Britain)European Research Council (ERC Advanced Grant IPCDP-229883)Swiss National Science Foundation (SNF Grant 100014-122636