680 research outputs found
Albumin concentrations are primarily determined by the body cell mass and the systemic inflammatory response in cancer patients with weight loss
The association between hypoalbuminemia and poor prognosis in patients with cancer is well recognized. However, the factors that contribute to the fall in albumin concentrations are not well understood. In the present study, we examined the relationship between circulating albumin concentrations, weight loss, the body cell mass (measured using total body potassium), and the presence of an inflammatory response (measured using C- reactive protein) in male patients (n=40) with advanced lung or gastrointestinal cancer. Albumin concentrations were significantly correlated with the percent ideal body weight (r=0.390, p lt 0.05), extent of reported weight loss (r=-0.492, p lt 0.01), percent predicted total body potassium (adjusted for age, height, and weight, r=0.686, p lt 0.001), and logo C-reactive protein concentrations (r=-0.545, p lt 0.001). On multiple regression analysis, the percent predicted total body potassium and log(10) C-reactive protein concentrations accounted for 63% of the variation in albumin concentrations (r(2) = 0.626, p lt 0.001). The interrelationship between albumin, body cell mass, and the inflammatory response is consistent with the concept that the presence of an ongoing inflammatory response contributes to the progressive loss of these vital protein components of the body and the subsequent death of patients with advanced cancer
Determining Principal Component Cardinality through the Principle of Minimum Description Length
PCA (Principal Component Analysis) and its variants areubiquitous techniques
for matrix dimension reduction and reduced-dimensionlatent-factor extraction.
One significant challenge in using PCA, is thechoice of the number of principal
components. The information-theoreticMDL (Minimum Description Length) principle
gives objective compression-based criteria for model selection, but it is
difficult to analytically applyits modern definition - NML (Normalized Maximum
Likelihood) - to theproblem of PCA. This work shows a general reduction of NML
prob-lems to lower-dimension problems. Applying this reduction, it boundsthe
NML of PCA, by terms of the NML of linear regression, which areknown.Comment: LOD 201
Diversity of Lecidea (Lecideaceae, Ascomycota) species revealed by molecular data and morphological characters
The diversity of lichens, especially crustose species, in continental Antarctica is still poorly known. To overcome difficulties with the morphology based species delimitations in these groups, we employed molecular data (nuclear ITS and mitochondrial SSU rDNA sequences) to test species boundaries within the genus Lecidea. Sampling was done along a north–south transect at five different areas in the Ross Sea region (Cape Hallett, Botany Bay to Mount Suess, Taylor Valley, Darwin Area and Mount Kyffin). A total of 153 specimens were collected from 13 localities. Phylogenetic analyses also include specimens from other regions in Antarctica and non-Antarctic areas. Maximum parsimony, maximum likelihood and Bayesian analyses agreed in placing the samples from continental Antarctica into four major groups. Based on this phylogenetic estimate, we restudied the micromorphology and secondary chemistry of these four clades to evaluate the use of these characters as phylogenetic discriminators. These clades are identified as the following species Lecidea cancriformis, L. andersonii as well as the new species L. polypycnidophora Ruprecht & Türk sp. nov. and another previously unnamed clade of uncertain status, referred to as Lecidea sp. (L. UCR1)
Structural changes in gill DNA reveal the effects of contaminants on Puget Sound fish.
Structural differences were identified in gill DNA from two groups of English sole collected from Puget Sound, Washington, in October 2000. One group was from the industrialized Duwamish River (DR) in Seattle and the other from relatively clean Quartermaster Harbor (QMH). Chemical markers of sediment contamination [e.g., polynuclear aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)] established that the DR was substantially more contaminated than QMH. The levels of these chemicals in the sediments of both sites were consistent with levels of cytochrome P450 1A (CYP1A) expression in the gills of English sole from the same sites. Structural differences in gill DNA between the groups were evinced via statistical models of Fourier transform-infrared (FT-IR) spectra. Marked structural damage was found in the gill DNA of the DR fish as reflected in differences in base functional groups (e.g., C-O and NH2) and conformational properties (e.g., arising from perturbations in vertical base stacking interactions). These DNA differences were used to discriminate between the two fish groups through principal components analysis of mean FT-IR spectra. In addition, logistic regression analysis allowed for the development of a "DNA damage index" to assess the effects of contaminants on the gill. The evidence implies that environmental chemicals contribute to the DNA changes in the gill. The damaged DNA is a promising marker for identifying, through gill biopsies, contaminant effects on fish
The modified Glasgow prognostic score in prostate cancer: results from a retrospective clinical series of 744 patients
<p>Background: As the incidence of prostate cancer continues to rise steeply, there is an increasing need to identify more accurate prognostic markers for the disease. There is some evidence that a higher modified Glasgow Prognostic Score (mGPS) may be associated with poorer survival in patients with prostate cancer but it is not known whether this is independent of other established prognostic factors. Therefore the aim of this study was to describe the relationship between mGPS and survival in patients with prostate cancer after adjustment for other prognostic factors.</p>
<p>Methods: Retrospective clinical series on patients in Glasgow, Scotland, for whom data from the Scottish Cancer Registry, including Gleason score, Prostate Specific Antigen (PSA), C-reactive protein (CRP) and albumin, six months prior to or following the diagnosis, were included in this study.</p>
<p>The mGPS was constructed by combining CRP and albumin. Five-year and ten-year relative survival and relative excess risk of death were estimated by mGPS categories after adjusting for age, socioeconomic circumstances, Gleason score, PSA and previous in-patient bed days.</p>
<p>Results: Seven hundred and forty four prostate cancer patients were identified; of these, 497 (66.8%) died during a maximum follow up of 11.9 years. Patients with mGPS of 2 had poorest 5-year and 10-year relative survival, of 32.6% and 18.8%, respectively. Raised mGPS also had a significant association with excess risk of death at five years (mGPS 2: Relative Excess Risk = 3.57, 95% CI 2.31-5.52) and ten years (mGPS 2: Relative Excess Risk = 3.42, 95% CI 2.25-5.21) after adjusting for age, socioeconomic circumstances, Gleason score, PSA and previous in-patient bed days.</p>
<p>Conclusions: The mGPS is an independent and objective prognostic indicator for survival of patients with prostate cancer. It may be useful in determining the clinical management of patients with prostate cancer in addition to established prognostic markers.</p>
Laminar flows - Subcellular positioning of small molecules
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62911/1/4111016a0.pd
Perturbation with Intrabodies Reveals That Calpain Cleavage Is Required for Degradation of Huntingtin Exon 1
Background:
Proteolytic processing of mutant huntingtin (mHtt), the protein that causes Huntington's disease (HD), is critical for mHtt toxicity and disease progression. mHtt contains several caspase and calpain cleavage sites that generate N-terminal fragments that are more toxic than full-length mHtt. Further processing is then required for the degradation of these fragments, which in turn, reduces toxicity. This unknown, secondary degradative process represents a promising therapeutic target for HD.
Methodology/Principal Findings: We have used intrabodies, intracellularly expressed antibody fragments, to gain insight into the mechanism of mutant huntingtin exon 1 (mHDx-1) clearance. Happ1, an intrabody recognizing the proline-rich region of mHDx-1, reduces the level of soluble mHDx-1 by increasing clearance. While proteasome and macroautophagy inhibitors reduce turnover of mHDx-1, Happ1 is still able to reduce mHDx-1 under these conditions, indicating Happ1-accelerated mHDx-1 clearance does not rely on these processes. In contrast, a calpain inhibitor or an inhibitor of lysosomal pH block Happ1-mediated acceleration of mHDx-1 clearance. These results suggest that mHDx-1 is cleaved by calpain, likely followed by lysosomal degradation and this process regulates the turnover rate of mHDx-1. Sequence analysis identifies amino acid (AA) 15 as a potential calpain cleavage site. Calpain cleavage of recombinant mHDx-1 in vitro yields fragments of sizes corresponding to this prediction. Moreover, when the site is blocked by binding of another intrabody, V_L12.3, turnover of soluble mHDx-1 in living cells is blocked.
Conclusions/Significance:
These results indicate that calpain-mediated removal of the 15 N-terminal AAs is required for the degradation of mHDx-1, a finding that may have therapeutic implications
Fetal Lead Exposure at Each Stage of Pregnancy as a Predictor of Infant Mental Development
BACKGROUND: The impact of prenatal lead exposure on neurodevelopment remains unclear in terms of consistency, the trimester of greatest vulnerability, and the best method for estimating fetal lead exposure. OBJECTIVE: We studied prenatal lead exposure’s impact on neurodevelopment using repeated measures of fetal dose as reflected by maternal whole blood and plasma lead levels. METHODS: We measured lead in maternal plasma and whole blood during each trimester in 146 pregnant women in Mexico City. We then measured umbilical cord blood lead at delivery and, when offspring were 12 and 24 months of age, measured blood lead and administered the Bayley Scales of Infant Development. We used multivariate regression, adjusting for covariates and 24-month blood lead, to compare the impacts of our pregnancy measures of fetal lead dose. RESULTS: Maternal lead levels were moderately high with a first-trimester blood lead mean (± SD) value of 7.1 ± 5.1 μg/dL and 14% of values ≥10 μg/dL. Both maternal plasma and whole blood lead during the first trimester (but not in the second or third trimester) were significant predictors (p < 0.05) of poorer Mental Development Index (MDI) scores. In models combining all three trimester measures and using standardized coefficients, the effect of first-trimester maternal plasma lead was somewhat greater than the effect of first-trimester maternal whole blood lead and substantially greater than the effects of second- or third-trimester plasma lead, and values averaged over all three trimesters. A 1-SD change in first-trimester plasma lead was associated with a reduction in MDI score of 3.5 points. Postnatal blood lead levels in the offspring were less strongly correlated with MDI scores. CONCLUSIONS: Fetal lead exposure has an adverse effect on neurodevelopment, with an effect that may be most pronounced during the first trimester and best captured by measuring lead in either maternal plasma or whole blood
An agriculture and health inter-sectorial research process to reduce hazardous pesticide health impacts among smallholder farmers in the Andes
Authors are also recipients of the Teasdale-Corti grant (103460-068)Work with multiple actors is needed to shift agriculture away from pesticide use, and towards greater sustainability and human health, particularly for vulnerable smallholder farmers. This research in potato and vegetable farming communities in the Andean highlands worked with partners from various sectors over several projects. Increased involvement in organic agriculture was associated with greater household food security and food sovereignty. More diversified, moderately developed agricultural systems had lower pesticide use and better child nutrition. The Ecuadorian Ministry of Health has rolled out pesticide poisoning surveillance modeled on this research
Rapid ascent of rhyolitic magma at Chaitén volcano, Chile
International audienceAlthough rhyolite magma has fuelled some of the Earth's largest explosive volcanic eruptions, our understanding of these events is incomplete due to the previous lack of direct observation of these eruptions. On 1 May 2008, Chaitén volcano in Chile erupted rhyolite magma unexpectedly and explosively. Here, petrological and experimental data are presented that indicate that the hydrous rhyolite magma at Chaitén ascended very rapidly from storage depth to near-surface, with velocities of the order of one metre per second
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