277 research outputs found
Living With Maternal HIV: Spirituality, Depression, And Family Functioning
Risk factors such as depression and low SES often affect an HIV infected mother’s ability to function within her family. Spirituality may interact with such risk factors contributing to the resiliency of these mothers. The current study explored spirituality’s influence on the relationship between depression and perceptions of family functioning in African American women living with HIV. High levels of spirituality were associated with decreased psychological distress and spirituality served as a significant predictor of family cohesion. Findings from this study support the importance of spirituality in the lives of African American women living with HIV and their families
A microbiological analysis of 210 cases of hand osteomyelitis
Objective
Osteomyelitis of the hand in adults often requires debridement of necrotic tissue and antibiotics targeted at organisms isolated from bone samples. This study aims to review organisms associated with hand osteomyelitis to inform clinical decision making.
Methods
A retrospective review of the organisms isolated from 210 patients with osteomyelitis of the phalanges and metacarpals of the hand in a major trauma centre was performed over twelve years.
Results
Microbiological cultures were performed for 195 patients including 122 with positive bone cultures. Staphylococcus aureus was identified in 104 patients (50%), with coagulase negative staphylococci in 57 (27%) and Enterobacterales in 53 (25%). Eighty-eight were polymicrobial infections (42%). Arterial calcification was associated with polymicrobial infections, Enterobacterales and enterococci. Multi-drug resistant organisms occurred in 13 patients and were more frequently Enterobacterales than staphylococci or enterococci.
Conclusions
The high incidence of polymicrobial infections and coagulase negative staphylococci in this series suggests that for suspected cases, early microbiological and histopathological confirmation, ideally via bone biopsy, is optimal for osteomyelitis of the hand.
Level of evidence: IV
Comparative biogeography of Southeast Asia and the West Pacific region
The file attached is the accepted/final draft post-refereeing version of the articl
Time-calibrated phylogenetic trees establish a lag between polyploidisation and diversification in Nicotiana (Solanaceae)
We investigate the timing of diversification in allopolyploids of Nicotiana (Solanaceae) utilising sequence data of maternal and paternal origin to look for evidence of a lag phase during which diploidisation took place. Bayesian relaxed clock phylogenetic methods show recent allopolyploids are a result of several unique polyploidisation events, and older allopolyploid sections have undergone subsequent speciation at the polyploid level (i.e. a number of these polyploid species share a singular origin). The independently formed recent polyploid species in the genus all have mean age estimates below 1 million years ago (Ma). Nicotiana section Polydicliae (two species) evolved 1.5 Ma, N. section Repandae (four species) formed 4 Ma, and N. section Suaveolentes (*35 species) is about 6 million years old. A general trend of higher speciation rates in older polyploids is evident, but diversification dramatically increases at approximately 6 Ma (in section Suaveolentes). Nicotiana sect. Suaveolentes has spectacularly radiated to form 35 species in Australia and some Pacific islands following a lag phase of almost 6 million years. Species have filled new ecological niches and undergone extensive diploidisation (e.g. chromosome fusions bringing the ancestral allotetraploid number, n = 24, down to n = 15 and ribosomal loci numbers back to diploid condition). Considering the progenitors of Suaveolentes inhabit South America, this represents the colonisation of Australia by polyploids that have subsequently undergone a recent radiation into new environments. To our knowledge, this study is the first report of a substantial lag phase being investigated below the family level
In Vivo Imaging Reveals Distinct Inflammatory Activity of CNS Microglia versus PNS Macrophages in a Mouse Model for ALS
Mutations in the enzyme superoxide dismutase-1 (SOD1) cause hereditary variants
of the fatal motor neuronal disease Amyotrophic lateral sclerosis (ALS).
Pathophysiology of the disease is non-cell-autonomous: neurotoxicity is derived
not only from mutant motor neurons but also from mutant neighbouring
non-neuronal cells. In vivo imaging by two-photon
laser-scanning microscopy was used to compare the role of
microglia/macrophage-related neuroinflammation in the CNS and PNS using
ALS-linked transgenic SOD1G93A mice. These mice contained labeled
projection neurons and labeled microglia/macrophages. In the affected lateral
spinal cord (in contrast to non-affected dorsal columns), different phases of
microglia-mediated inflammation were observed: highly reactive microglial cells
in preclinical stages (in 60-day-old mice the reaction to axonal transection was
∼180% of control) and morphologically transformed microglia that have
lost their function of tissue surveillance and injury-directed response in
clinical stages (reaction to axonal transection was lower than 50% of
control). Furthermore, unlike CNS microglia, macrophages of the PNS lack any
substantial morphological reaction while preclinical degeneration of peripheral
motor axons and neuromuscular junctions was observed. We present in
vivo evidence for a different inflammatory activity of microglia
and macrophages: an aberrant neuroinflammatory response of microglia in the CNS
and an apparently mainly neurodegenerative process in the PNS
The Effect of Inappropriate Calibration: Three Case Studies in Molecular Ecology
Time-scales estimated from sequence data play an important role in molecular ecology. They can be used to draw correlations between evolutionary and palaeoclimatic events, to measure the tempo of speciation, and to study the demographic history of an endangered species. In all of these studies, it is paramount to have accurate estimates of time-scales and substitution rates. Molecular ecological studies typically focus on intraspecific data that have evolved on genealogical scales, but often these studies inappropriately employ deep fossil calibrations or canonical substitution rates (e.g., 1% per million years for birds and mammals) for calibrating estimates of divergence times. These approaches can yield misleading estimates of molecular time-scales, with significant impacts on subsequent evolutionary and ecological inferences. We illustrate this calibration problem using three case studies: avian speciation in the late Pleistocene, the demographic history of bowhead whales, and the Pleistocene biogeography of brown bears. For each data set, we compare the date estimates that are obtained using internal and external calibration points. In all three cases, the conclusions are significantly altered by the application of revised, internally-calibrated substitution rates. Collectively, the results emphasise the importance of judicious selection of calibrations for analyses of recent evolutionary events
Expression and regulation of type 2A protein phosphatases and alpha4 signalling in cardiac health and hypertrophy
Abstract Cardiac physiology and hypertrophy are regulated
by the phosphorylation status of many proteins, which
is partly controlled by a poorly defined type 2A protein
phosphatase-alpha4 intracellular signalling axis. Quantitative
PCR analysis revealed that mRNA levels of the type
2A catalytic subunits were differentially expressed in H9c2
cardiomyocytes (PP2ACb[PP2ACa[PP4C[PP6C),
NRVM (PP2ACb[PP2ACa = PP4C = PP6C), and
adult rat ventricular myocytes (PP2ACa[
PP2ACb[PP6C[PP4C). Western analysis confirmed
that all type 2A catalytic subunits were expressed in H9c2
cardiomyocytes; however, PP4C protein was absent in
adult myocytes and only detectable following 26S proteasome
inhibition. Short-term knockdown of alpha4 protein
expression attenuated expression of all type 2A catalytic
subunits. Pressure overload-induced left ventricular (LV)
hypertrophy was associated with an increase in both
PP2AC and alpha4 protein expression. Although PP6C
expression was unchanged, expression of PP6C regulatory
subunits (1) Sit4-associated protein 1 (SAP1) and (2)
ankyrin repeat domain (ANKRD) 28 and 44 proteins was
elevated, whereas SAP2 expression was reduced in
hypertrophied LV tissue. Co-immunoprecipitation studies
demonstrated that the interaction between alpha4 and
PP2AC or PP6C subunits was either unchanged or reduced
in hypertrophied LV tissue, respectively. Phosphorylation
status of phospholemman (Ser63 and Ser68) was significantly
increased by knockdown of PP2ACa, PP2ACb, or
PP4C protein expression. DNA damage assessed by histone
H2A.X phosphorylation (cH2A.X) in hypertrophied tissue
remained unchanged. However, exposure of cardiomyocytes
to H2O2 increased levels of cH2A.X which was
unaffected by knockdown of PP6C expression, but was
abolished by the short-term knockdown of alpha4 expression.
This study illustrates the significance and altered
activity of the type 2A protein phosphatase-alpha4 complex
in healthy and hypertrophied myocardium
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