4,221 research outputs found
Portal vein embolization versus dual vein embolization for management of the future liver remnant in patients undergoing major hepatectomy: meta-analysis
BACKGROUND: This meta-analysis aimed to compare progression to surgery, extent of liver hypertrophy, and postoperative outcomes in patients planned for major hepatectomy following either portal vein embolization (PVE) or dual vein embolization (DVE) for management of an inadequate future liver remnant (FLR). METHODS: An electronic search was performed of MEDLINE, Embase, and PubMed databases using both medical subject headings (MeSH) and truncated word searches. Articles comparing PVE with DVE up to January 2022 were included. Articles comparing sequential DVE were excluded. ORs, risk ratios, and mean difference (MD) were calculated using fixed and random-effects models for meta-analysis. RESULTS: Eight retrospective studies including 523 patients were included in the study. Baseline characteristics between the groups, specifically, age, sex, BMI, indication for resection, and baseline FLR (ml and per cent) were comparable. The percentage increase in hypertrophy was larger in the DVE group, 66 per cent in the DVE group versus 27 per cent in the PVE group, MD 39.07 (9.09, 69.05) (P = 0.010). Significantly fewer patients failed to progress to surgery in the DVE group than the PVE group, 13 per cent versus 25 per cent respectively OR 0.53 (0.31, 0.90) (P = 0.020). Rates of post-hepatectomy liver failure 13 per cent versus 22 per cent (P = 0.130) and major complications 20 per cent versus 28 per cent (Clavien–Dindo more than IIIa) (P = 0.280) were lower. Perioperative mortality was lower with DVE, 1 per cent versus 10 per cent (P = 0.010). CONCLUSION: DVE seems to produce a greater degree of hypertrophy of the FLR than PVE alone which translates into more patients progressing to surgery. Higher quality studies are needed to confirm these results
State Effects of Two Forms of Meditation on Prefrontal EEG Asymmetry in Previously Depressed Individuals
We investigated state effects of two forms of meditation on electroencephalography prefrontal α-asymmetry, a global indicator of approach versus withdrawal motivation and related affective state. A clinical series of previously depressed individuals were guided to practice either mindfulness breathing meditation (N = 8) or a form of meditation directly aimed at cultivating positive affect, loving kindness or metta meditation (N = 7). Prefrontal asymmetry was assessed directly before and after the 15-min meditation period. Results showed changes in asymmetry towards stronger relative left prefrontal activation, i.e., stronger approach tendencies, regardless of condition. Further explorations of these findings suggested that responses were moderated by participants’ tendencies to engage in ruminative brooding. Individuals high in brooding tended to respond to breathing meditation but not loving kindness meditation, while those low in brooding showed the opposite pattern. Comparisons with an additionally recruited “rest” group provided evidence suggesting that changes seen were not simply attributable to habituation. The results indicate that both forms of meditation practice can have beneficial state effects on prefrontal α-asymmetry and point towards differential indications for offering them in the treatment of previously depressed patients
Identification of liver metastases with probe-based confocal laser endomicroscopy at two excitation wavelengths.
BACKGROUND: Metastasis of colorectal cancer to the liver is the most common indication for hepatic resection in a western population. Incomplete excision of malignancy due to residual microscopic disease normally results in worse patient outcome. Therefore, a method aiding in the real time discrimination of normal and malignant tissue on a microscopic level would be of benefit. MATERIAL AND METHODS: The ability of fluorescent probe-based confocal laser endomicroscopy (pCLE) to identify normal and malignant liver tissue was evaluated in an orthotopic murine model of colorectal cancer liver metastasis (CRLM). To maximise information yield, two clinical fluorophores, fluorescein and indocyanine green (ICG) were injected and imaged in a dual wavelength approach (488 and 660 nm, respectively). Visual tissue characteristics on pCLE examination were compared with histological features. Fluorescence intensity in both tissues was statistically analysed to elucidate if this can be used to differentiate between normal and malignant tissue. RESULTS: Fluorescein (488 nm) enabled good visualisation of normal and CRLM tissue, whereas ICG (660 nm) visualisation was limited to normal liver tissue only. Fluorescence intensity in areas of CRLM was typically 53-100% lower than normal hepatic parenchyma. Using general linear mixed modelling and receiver operating characteristic analysis, high fluorescence intensity was found to be statistically more likely in normal hepatic tissue. CONCLUSION: Real time discrimination between normal liver parenchyma and metastatic tissue with pCLE examination of fluorescein and ICG is feasible. Employing two (rather than a single) fluorophores allows a combination of qualitative and quantitative characteristics to be used to distinguish between hepatic parenchyma and CRLM. Lasers Surg. Med. © 2016 Wiley Periodicals, Inc
Molecular heterogeneity in major urinary proteins of Mus musculus subspecies: potential candidates involved in speciation
When hybridisation carries a cost, natural selection is predicted to favour evolution of traits that allow assortative mating (reinforcement). Incipient speciation between the two European house mouse subspecies, Mus musculus domesticus and M.m.musculus, sharing a hybrid zone, provides an opportunity to understand evolution of assortative mating at a molecular level. Mouse urine odours allow subspecific mate discrimination, with assortative preferences evident in the hybrid zone but not in allopatry. Here we assess the potential of MUPs (major urinary proteins) as candidates for signal divergence by comparing MUP expression in urine samples from the Danish hybrid zone border (contact) and from allopatric populations. Mass spectrometric characterisation identified novel MUPs in both subspecies involving mostly new combinations of amino acid changes previously observed in M.m.domesticus. The subspecies expressed distinct MUP signatures, with most MUPs expressed by only one subspecies. Expression of at least eight MUPs showed significant subspecies divergence both in allopatry and contact zone. Another seven MUPs showed divergence in expression between the subspecies only in the contact zone, consistent with divergence by reinforcement. These proteins are candidates for the semiochemical barrier to hybridisation, providing an opportunity to characterise the nature and evolution of a putative species recognition signal
Polygenic Risk Scoring is an Effective Approach to Predict Those Individuals Most Likely to Decline Cognitively Due to Alzheimer’s Disease
BACKGROUND: There is a clear need for simple and effective tests to identify individuals who are most likely to develop Alzheimer’s Disease (AD) both for the purposes of clinical trial recruitment but also for improved management of patients who may be experiencing early pre-clinical symptoms or who have clinical concerns. OBJECTIVES: To predict individuals at greatest risk of progression of cognitive impairment due to Alzheimer’s Disease in individuals from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) using a polygenic risk scoring algorithm. To compare the performance of a PRS algorithm in predicting cognitive decline against that of using the pTau/Aß1-42 ratio CSF biomarker profile. DESIGN: A longitudinal analysis of data from the Alzheimer’s Disease Neuroimaging Initiative study conducted across over 50 sites in the US and Canada. SETTING: Multi-center genetics study. PARTICPANTS: 515 subjects who upon entry to the study were diagnosed as cognitively normal or with mild cognitive impairment. MEASUREMENTS: Use of genotyping and/or whole genome sequencing data to calculate polygenic risk scores and assess ability to predict subsequent cognitive decline as measured by CDR-SB and ADAS-Cog13 over 4 years RESULTS: The overall performance for predicting those individuals who would decline by at least 15 ADAS-Cog13 points from a baseline mild cognitive impairment in 4 years was 72.8% (CI:67.9-77.7) AUC increasing to 79.1% (CI: 75.6-82.6) when also including cognitively normal participants. Assessing mild cognitive impaired subjects only and using a threshold of greater than 0.6, the high genetic risk participant group declined, on average, by 1.4 points (CDR-SB) more than the low risk group over 4 years. The performance of the PRS algorithm tested was similar to that of the pTau/Aß1-42 ratio CSF biomarker profile in predicting cognitive decline. CONCLUSION: Calculating polygenic risk scores offers a simple and effective way, using DNA extracted from a simple mouth swab, to select mild cognitively impaired patients who are most likely to decline cognitively over the next four years
Eta Carinae -- Physics of the Inner Ejecta
Eta Carinae's inner ejecta are dominated observationally by the bright
Weigelt blobs and their famously rich spectra of nebular emission and
absorption lines. They are dense (n_e ~ 10^7 to 10^8 cm^-3), warm (T_e ~ 6000
to 7000 K) and slow moving (~40 km/s) condensations of mostly neutral (H^0)
gas. Located within 1000 AU of the central star, they contain heavily
CNO-processed material that was ejected from the star about a century ago.
Outside the blobs, the inner ejecta include absorption-line clouds with similar
conditions, plus emission-line gas that has generally lower densities and a
wider range of speeds (reaching a few hundred km/s) compared to the blobs. The
blobs appear to contain a negligible amount of dust and have a nearly dust-free
view of the central source, but our view across the inner ejecta is severely
affected by uncertain amounts of dust having a patchy distribution in the
foreground. Emission lines from the inner ejecta are powered by photoionization
and fluorescent processes. The variable nature of this emission, occurring in a
5.54 yr event cycle, requires specific changes to the incident flux that hold
important clues to the nature of the central object.Comment: This is Chapter 5 in a book entitled: Eta Carinae and the Supernova
Impostors, Kris Davidson and Roberta M. Humphreys, editors Springe
Re-weighting of somatosensory inputs from the foot and the ankle for controlling posture during quiet standing following trunk extensor muscles fatigue
The present study focused on the effects of trunk extensor muscles fatigue on
postural control during quiet standing under different somatosensory conditions
from the foot and the ankle. With this aim, 20 young healthy adults were asked
to stand as immobile as possible in two conditions of No fatigue and Fatigue of
trunk extensor muscles. In Experiment 1 (n = 10), somatosensation from the foot
and the ankle was degraded by standing on a foam surface. In Experiment 2 (n =
10), somatosensation from the foot and ankle was facilitated through the
increased cutaneous feedback at the foot and ankle provided by strips of
athletic tape applied across both ankle joints. The centre of foot pressure
displacements (CoP) were recorded using a force platform. The results showed
that (1) trunk extensor muscles fatigue increased CoP displacements under
normal somatosensatory conditions (Experiment 1 and Experiment 2), (2) this
destabilizing effect was exacerbated when somatosensation from the foot and the
ankle was degraded (Experiment 1), and (3) this destabilizing effect was
mitigated when somatosensation from the foot and the ankle was facilitated
(Experiment 2). Altogether, the present findings evidenced re-weighting of
sensory cues for controlling posture during quiet standing following trunk
extensor muscles fatigue by increasing the reliance on the somatosensory inputs
from the foot and the ankle. This could have implications in clinical and
rehabilitative areas
Combined Microscopy, Calorimetry and X-ray Scattering Study of Fluorinated Dimesogens
The material FDO11DFCB3 (compound 2 in this work) remains the only example of a liquid-crystalline material to exhibit a phase transition from the heliconical twist-bend phase into a lamellar smectic A mesophase, additionally this material exhibits a previously unidentified mesophase. We have prepared and characterised several homologues of this compound, with each material subjected to an in-depth analysis by optical microscopy, calorimetry and small angle X-ray scattering studies. Despite FDO11DFCB3 being similar in chemical structure to the novel materials presented herein its liquid-crystalline behaviour is rather different, indicating an unexpected sensitivity of the twist-bend phase to molecular structure
Characterisation of urinary WFDC12 in small nocturnal basal primates, mouse lemurs (Microcebus spp.)
Mouse lemurs are basal primates that rely on chemo- and acoustic signalling for social interactions in their dispersed social systems. We examined the urinary protein content of two mouse lemurs species, within and outside the breeding season, to assess candidates used in species discrimination, reproductive or competitive communication. Urine from Microcebus murinus and Microcebus lehilahytsara contain a predominant 10 kDa protein, expressed in both species by some, but not all, males during the breeding season, but at very low levels by females. Mass spectrometry of the intact proteins confirmed the protein mass and revealed a 30 Da mass difference between proteins from the two species. Tandem mass spectrometry after digestion with three proteases and sequencing de novo defined the complete protein sequence and located an Ala/Thr difference between the two species that explained the 30 Da mass difference. The protein (mature form: 87 amino acids) is an atypical member of the whey acidic protein family (WFDC12). Seasonal excretion of this protein, species difference and male-specific expression during the breeding season suggest that it may have a function in intra- and/or intersexual chemical signalling in the context of reproduction, and could be a cue for sexual selection and species recognition
Neuroimaging and biomarker evidence of neurodegeneration in asthma
Background: Epidemiological studies have shown that Alzheimer’s disease and related dementias (ADRD) are seen more frequently with asthma, especially with greater asthma severity or exacerbation frequency. // Objective: To examine the changes in brain structure that may underlie this phenomenon, we examined diffusion-weighted magnetic resonance imaging (dMRI) and blood-based biomarkers of AD (p-Tau181), neurodegeneration (NfL) and glial activation (GFAP). // Methods: dMRI data were obtained in 111 individuals with asthma, ranging in disease severity from mild to severe, and 135 healthy controls. Regression analyses were used to test the relationships between asthma severity and neuroimaging measures, as well as AD pathology, neurodegeneration and glial activation, indexed by plasma p-Tau181, NfL and GFAP respectively. Additional relationships were tested with cognitive function. // Results: Asthma participants had widespread and large magnitude differences in several dMRI metrics, which were indicative of neuroinflammation and neurodegeneration, and robustly associated with GFAP and to a lesser extent, with NfL. The AD biomarker p-Tau181 was only minimally associated with neuroimaging outcomes. Further, asthma severity was associated with deleterious changes in neuroimaging outcomes, which in turn, were associated with slower processing speed, a test of cognitive performance. // Conclusion: These data suggest that asthma, particularly when severe, is associated with characteristics of neuroinflammation and neurodegeneration and may be a potential risk factor for neural injury and cognitive dysfunction. The results suggest a need to determine how asthma may affect brain health and whether treatment directed toward characteristics of asthma associated with these risks can mitigate these effects
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