Ventricular assist device (VAD) management continues to be a challenge in the presence of restrictive physiology. Left atrial (LA) decompression is not satisfactory even with good function and position of the left ventricular cannula. We describe an alternate approach with LA cannulation via the left atrial appendage (LAA) as a rescue strategy in a patient who had restrictive physiology, in our case was secondary to viral myocarditis acute systolic heart failure with subsequent insidious diffuse endomyocardial fibrosis and superimposed massive calcification, causing inadequate emptying of the left ventricle despite optimal VAD apical cannula position.
View Article and Find Full Text PDFEntropy (Basel)
May 2020
The methods of statistical physics are exemplified in the classical perfect gas-each atom is a single dynamical entity. Such methods can be applied in ecology to the distribution of cosmopolitan species over many sites. The analogue of an atom is a class of species distinguished by the number of sites at which it occurs, hardly a material entity; yet, the methods of statistical physics nonetheless seem applicable.
View Article and Find Full Text PDFMagnetic resonance imaging (MRI) is a clinically relevant non-invasive imaging tool commonly utilized to assess stroke progression in real time. This study investigated the utility of MRI as a predictive measure of clinical and functional outcomes when a stroke intervention is withheld or provided, in order to identify biomarkers for stroke functional outcome under these conditions. Fifteen MRI and ninety functional parameters were measured in a middle cerebral artery occlusion (MCAO) porcine ischemic stroke model.
View Article and Find Full Text PDFThe lack of effective therapies for moderate-to-severe traumatic brain injuries (TBIs) leaves patients with lifelong disabilities. Neural stem cells (NSCs) have demonstrated great promise for neural repair and regeneration. However, direct evidence to support their use as a cell replacement therapy for neural injuries is currently lacking.
View Article and Find Full Text PDFData on the seasonally dry tropical forests of Mexico have been examined in the light of statistical mechanics. The results suggest a division into two classes of species. There are drifting populations of a cosmopolitan class capable of existing in most dry forest sites; these have a statistical distribution previously only observed (globally) for populations of alien species.
View Article and Find Full Text PDFThe humidity surrounding a sample is an important variable in scientific experiments. Biological samples in particular require not just a humid atmosphere but often a relative humidity (RH) that is in equilibrium with a stabilizing solution required to maintain the sample in the same state during measurements. The controlled dehydration of macromolecular crystals can lead to significant increases in crystal order, leading to higher diffraction quality.
View Article and Find Full Text PDFCongenital anomalies of the kidney and urogenital tract (CAKUT) occur in approximately 0.5% of live births and represent the most frequent cause of end-stage renal disease in neonates and children. The genetic basis of CAKUT is not well defined.
View Article and Find Full Text PDFPurpose: The aim of the present study was to assess pain, function, diet, and quality of life (QOL) in subjects undergoing alloplastic temporomandibular joint (TMJ) reconstruction.
Materials And Methods: A total of 72 subjects were sent a questionnaire an average of 4 years after undergoing either unilateral or bilateral total joint replacement with a custom TMJ Concepts or stock Biomet total joint replacement device. The changes in pain, function, diet, and quality of life were assessed.
Acta Crystallogr F Struct Biol Commun
January 2014
The advent of micro-focused X-ray beams has led to the development of a number of advanced methods of sample evaluation and data collection. In particular, multiple-position data-collection and helical oscillation strategies are now becoming commonplace in order to alleviate the problems associated with radiation damage. However, intra-crystal and inter-crystal variation means that it is not always obvious on which crystals or on which region or regions of a crystal these protocols should be performed.
View Article and Find Full Text PDFA central issue in ecology is that of the factors determining the relative abundance of species within a natural community. The proper application of the principles of statistical physics to species abundance distributions (SADs) shows that simple ecological properties could account for the near universal features observed. These properties are (i) a limit on the number of individuals in an ecological guild and (ii) per capita birth and death rates.
View Article and Find Full Text PDFActa Crystallogr Sect F Struct Biol Cryst Commun
January 2012
The dehydration of crystals of macromolecules has long been known to have the potential to increase their diffraction quality. A number of methods exist to change the relative humidity that surrounds crystals, but for reproducible results, with complete characterization of the changes induced, a precise humidity-control device coupled with an X-ray source is required. The first step in these experiments is to define the relative humidity in equilibrium with the mother liquor of the system under study; this can often be quite time-consuming.
View Article and Find Full Text PDF• Theoretically, communities at or near their equilibrium species number resist entry of new species. Such 'biotic resistance' recently has been questioned because of successful entry of alien species into diverse natural communities. • Data on 10,409 naturalizations of 5350 plant species over 16 sites dispersed globally show exponential distributions both for species over sites and for sites over number of species shared.
View Article and Find Full Text PDFThe mammalian circadian clock component PERIOD2 (PER2) plays a critical role in circadian rhythm entrainment. Recently, a missense mutation at a putative phosphorylation site in hPER2, Ser-662, was identified in patients that suffer from familial advanced sleep phase syndrome (FASPS). Patients with FASPS display abnormal sleep-wake patterns characterized by a lifelong pattern of sleep onset in the early evening and offset in the early morning.
View Article and Find Full Text PDFAmyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease that preferentially targets motor neurons. It was recently found that dominant mutations in two related RNA-binding proteins, TDP-43 (43-kDa TAR DNA-binding domain protein) and FUS/TLS (fused in sarcoma/translated in liposarcoma) cause a subset of ALS. The convergent ALS phenotypes associated with TDP-43 and FUS/TLS mutations are suggestive of a functional relationship; however, whether or not TDP-43 and FUS/TLS operate in common biochemical pathways is not known.
View Article and Find Full Text PDFThe impact of herbivores and other pests on plants varies greatly from year to year. Here we develop an analytical model of a temporal niche dynamic as a tool to examine how natural fluctuations in pest (enemy) levels may determine coexistence in competing annual plant species when one but not the other is affected by the pest. We show that the probability and speed with which the resistant drives out the sensitive species, coexists with it, or is driven out by its sensitive competitor depends on the cost of pest-resistance to the unaffected species, the frequency of high pest levels in the habitat and the competitive advantage of the sensitive species when the pest is not actively present.
View Article and Find Full Text PDFSmall-molecule inhibitors of protein kinases have contributed immensely to our understanding of biological signaling pathways and have been exploited therapeutically for the treatment of cancers and other disease states. The pyridinyl imidazole compounds SB 203580 and SB 202190 were identified as ATP competitive antagonists of the p38 stress-activated protein kinases and have been widely used to elucidate p38-dependent cellular processes. Here, we identify SB 203580 and SB 202190 as potent inhibitors of stress-induced CREB phosphorylation on Serine 111 (Ser-111) in intact cells.
View Article and Find Full Text PDFTDP-43 (43-kDa TAR DNA-binding domain protein) is a major constituent of ubiquitin-positive cytoplasmic aggregates present in neurons of patients with fronto-temporal lobular dementia and amyotrophic lateral sclerosis (ALS). The pathologic significance of TDP-43 aggregation is not known; however, dominant mutations in TDP-43 cause a subset of ALS cases, suggesting that misfolding and/or altered trafficking of TDP-43 is relevant to the disease process. Here, we show that the presenilin-binding protein ubiquilin 1 (UBQLN) plays a role in TDP-43 aggregation.
View Article and Find Full Text PDFCommunity structure refers to the number of species in a community and the pattern of distribution of individuals among those species. We use a novel way of representing community structure to show that abundance within closely related pairs of co-occurring tree species in a highly diverse Mexican forest is more equitable than is abundance within more distantly related pairs. This observation is at odds with the fundamental assumption of neutral models of community structure, i.
View Article and Find Full Text PDFThe potential effects of 'escape' of genetically modified material (transgenes) into natural communities is a major concern in their use. These effects may be limited in the first instance by limiting the proportion of transgene-carrying plants in the natural community. We previously presented an analytical model of the ecological processes governing the relative abundance and persistence of insect resistance (IR) transgenes in a natural community.
View Article and Find Full Text PDFWe examine the role of ecological interactions on effective gene flow from genetically manipulated plants to their wild relatives. We do so by constructing and applying to oilseed rape (OSR) an analytical model for interaction between plants with and without an insect resistance (IR) allele in natural communities, incorporating documented levels of herbivore variability. We find that with reasonable values of advantage to the IR allele, little concomitant disadvantage (physiological costs of the allele) restricts it to low proportions of the natural population for large numbers of generations.
View Article and Find Full Text PDFContemporary acceleration of biodiversity loss makes increasingly urgent the need to understand the controls of species coexistence. Tree diversity in particular plays a pivotal role in determining terrestrial biodiversity, through maintaining diversity of its dependent species and with them, their predators and parasites. Most theories of coexistence based on the principle of limiting similarity suggest that coexistence of competing species is inherently unstable; coexistence of competitors must be maintained by external forces such as disturbance, immigration or 'patchiness' of resources in space and time.
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