302 research outputs found
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Estimating future bidding performance of competitor bidders in capped tenders
Research in Bid Tender Forecasting Models (BTFM) has been in progress since the 1950s. None of the developed models were easy-to-use tools for effective use by bidding practitioners because the advanced mathematical apparatus and massive data inputs required. This scenario began to change in 2012 with the development of the Smartbid BTFM, a quite simple model that presents a series of graphs that enables any project manager to study competitors using a relatively short historical tender dataset. However, despite the advantages of this new model, so far, it is still necessary to study all the auction participants as an indivisible group; that is, the original BTFM was not devised for analyzing the behavior of a single bidding competitor or a subgroup of them. The present paper tries to solve that flaw and presents a stand-alone methodology useful for estimating future competitors’ bidding behaviors separately
Proteolytic enzyme engineering : a tool for wool
One of the goals of protein engineering is to tailor the structure of enzymes to optimize industrial bioprocesses. In the present work, we present the construction of a novel high molecular weight subtilisin, based on the fusion of the DNA sequences coding for Bacillus subtilis prosubtilisin E and for an elastin-like polymer (ELP). The resulting fusion protein was biologically produced in Escherichia coli, purified and used for wool finishing assays. When compared to the commercial protease Esperase, the recombinant subtilisinE-VPAVG220 activity was restricted to the cuticle of wool, allowing a significant reduction of pilling, weight loss and tensile strength loss of wool fibers. Here we report, for the first time, the microbial production of a functionalized high molecular weight protease for controlled enzymatic hydrolysis of wool surface. This original process overcomes the unrestrained diffusion and extended fiber damage which are the major obstacles for the use of proteases for wool finishing applications
Role of mitochondrial raft-like microdomains in the regulation of cell apoptosis
Lipid rafts are envisaged as lateral assemblies of specific lipids and proteins that dissociate and associate rapidly and form functional clusters in cell membranes. These structural platforms are not confined to the plasma membrane; indeed lipid microdomains are similarly formed at subcellular organelles, which include endoplasmic reticulum, Golgi and mitochondria, named raft-like microdomains. In addition, some components of raft-like microdomains are present within ER-mitochondria associated membranes. This review is focused on the role of mitochondrial raft-like microdomains in the regulation of cell apoptosis, since these microdomains may represent preferential sites where key reactions take place, regulating mitochondria hyperpolarization, fission-associated changes, megapore formation and release of apoptogenic factors. These structural platforms appear to modulate cytoplasmic pathways switching cell fate towards cell survival or death. Main insights on this issue derive from some pathological conditions in which alterations of microdomains structure or function can lead to severe alterations of cell activity and life span. In the light of the role played by raft-like microdomains to integrate apoptotic signals and in regulating mitochondrial dynamics, it is conceivable that these membrane structures may play a role in the mitochondrial alterations observed in some of the most common human neurodegenerative diseases, such as Amyotrophic lateral sclerosis, Huntington's chorea and prion-related diseases. These findings introduce an additional task for identifying new molecular target(s) of pharmacological agents in these pathologies
Study on COgnition and Prognosis in the Elderly (SCOPE): baseline characteristics
Blood Press. 2000;9(2-3):146-51.
Study on COgnition and Prognosis in the Elderly (SCOPE): baseline characteristics.
Hansson L, Lithell H, Skoog I, Baro F, Bánki CM, Breteler M, Castaigne A, Correia M, Degaute JP, Elmfeldt D, Engedal K, Farsang C, Ferro J, Hachinski V, Hofman A, James OF, Krisin E, Leeman M, de Leeuw PW, Leys D, Lobo A, Nordby G, Olofsson B, Opolski G, Prince M, Reischies FM.
University of Uppsala, Department of Public Health, Clinical Hypertension Research, Sweden.
Abstract
The Study on COgnition and Prognosis in the Elderly (SCOPE) is a multi-centre, prospective, randomized, double-blind, parallel-group study. The primary objective of SCOPE is to assess the effect of the angiotensin II type 1 (AT1) receptor blocker, candesartan cilexetil 8-16 mg once daily, on major cardiovascular events in elderly patients (70-89 years of age) with mild hypertension (DBP 90-99 and/or SBP 160-179 mmHg). The secondary objectives of the study are to test the hypothesis that antihypertensive therapy can prevent cognitive decline (as measured by the Mini Mental State Examination, MMSE) and dementia, and to assess the effect of therapy on total mortality, myocardial infarction (MI), stroke, renal function, and hospitalization. A total of 4964 patients from 15 participating countries were recruited during the randomization phase of SCOPE, exceeding the target population of 4000. The mean age of the patients at enrolment was 76 years, the ratio of male to female patients was approximately 1:2, and 52% of patients were already being treated with an antihypertensive agent at enrolment. The majority of patients (88%) were educated to at least primary school level. At randomization, mean sitting blood pressure values were SBP 166 mmHg and DBP 90 mmHg, and the mean MMSE score was 28. Previous cardiovascular disease in the study population included myocardial infarction (4%), stroke (4%) and atrial fibrillation (4%). Men, more often than women, had a history of previous MI, stroke and atrial fibrillation. A greater percentage of men were smokers (13% vs 6% in women) and had attended university (11% vs 3% of women). Of the randomized patients, 21% were 80 years of age. In this age group smoking was less common (4% vs 10% for 70-79-year-olds) and fewer had attended university (4% vs 7% for 70-79-year-olds). The incidence of MI was similar in both age groups. However, stroke and atrial fibrillation had occurred approximately twice as frequently in the older patients. The patients' mean age at baseline was similar in the participating countries, and most countries showed the approximate 1:2 ratio for male to female patients. There was also little inter-country variation in terms of mean SBP, DBP or MMSE score. However, there was considerable regional variation in the percentage of patients on therapy prior to enrolment.
PMID: 10855739 [PubMed - indexed for MEDLINE
Study on COgnition and Prognosis in the Elderly (SCOPE)
Blood Press. 1999;8(3):177-83.
Study on COgnition and Prognosis in the Elderly (SCOPE).
Hansson L, Lithell H, Skoog I, Baro F, Bánki CM, Breteler M, Carbonin PU, Castaigne A, Correia M, Degaute JP, Elmfeldt D, Engedal K, Farsang C, Ferro J, Hachinski V, Hofman A, James OF, Krisin E, Leeman M, de Leeuw PW, Leys D, Lobo A, Nordby G, Olofsson B, Zanchetti A, et al.
University of Uppsala, Department of Public Health, Sweden.
Abstract
The Study on COgnition and Prognosis in the Elderly (SCOPE) is a multicentre, prospective, randomized, double-blind, parallel-group study designed to compare the effects of candesartan cilexetil and placebo in elderly patients with mild hypertension. The primary objective of the study is to assess the effect of candesartan cilexetil on major cardiovascular events. The secondary objectives of the study are to assess the effect of candesartan cilexetil on cognitive function and on total mortality, cardiovascular mortality, myocardial infarction, stroke, renal function, hospitalization, quality of life and health economics. Male and female patients aged between 70 and 89 years, with a sitting systolic blood pressure (SBP) of 160-179 mmHg and/or diastolic blood pressure (DBP) of 90-99 mmHg, and a Mini-Mental State Examination (MMSE) score of 24 or above, are eligible for the study. The overall target study population is 4000 patients, at least 1000 of whom are also to be assessed for quality of life and health economics data. After an open run-in period lasting 1-3 months, during which patients are assessed for eligibility and those who are already on antihypertensive therapy at enrolment are switched to hydrochlorothiazide 12.5 mg o.d., patients are randomized to receive either candesartan cilexetil 8 mg once daily (o.d.) or matching placebo o.d. At subsequent study visits, if SBP remains >160 mmHg, or has decreased by 85 mmHg, study treatment is doubled to candesartan cilexetil 16 mg o.d. or two placebo tablets o.d. Recruitment was completed in January 1999. At that time 4964 patients had been randomized. All randomized patients will be followed for an additional 2 years. If the event rate is lower than anticipated, the follow-up will be prolonged.
PMID: 10595696 [PubMed - indexed for MEDLINE
CSF biochemical correlates of mixed affective states
To evaluate the question of whether “mixed” bipolar disorder is a distinct entity, we compared selected cerebrospinal fluid (CSF) biochemical parameters from patients with bipolar disorder, mixed, to those with mania and major depression. Fourteen patients in each category (DSM-III) were studied with regard to CSF HVA, 5HIAA, sodium, potassium, calcium, and magnesium levels under carefully controlled conditions. CSF HVA, 5HIAA, and sodium were found to be significantly higher in manics than in major depressives. Discriminant analysis of the biochemical variables of the mixed affective group identified two biochemically distinct and clinically different subgroups of seven patients each, one resembling the manic group and the other the major depressive group. These findings suggest that mixed affective states do not exist as a separate entity, but are compsed of two subgroups obtained from the manic and major depressive categories.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66203/1/j.1600-0447.1988.tb06339.x.pd
Protective Intestinal Effects of Pituitary Adenylate Cyclase Activating Polypeptide
Pituitary adenylate cyclase activating polypeptide (PACAP) is an
endogenous neuropeptide widely distributed throughout the body, including the
gastrointestinal tract. Several effects have been described in human and animal
intestines. Among others, PACAP infl uences secretion of intestinal glands, blood
fl ow, and smooth muscle contraction. PACAP is a well-known cytoprotective peptide
with strong anti-apoptotic, anti-infl ammatory, and antioxidant effects. The
present review gives an overview of the intestinal protective actions of this neuropeptide.
Exogenous PACAP treatment was protective in a rat model of small bowel
autotransplantation. Radioimmunoassay (RIA) analysis of the intestinal tissue showed that endogenous PACAP levels gradually decreased with longer-lasting
ischemic periods, prevented by PACAP addition. PACAP counteracted deleterious
effects of ischemia on oxidative stress markers and cytokines. Another series of
experiments investigated the role of endogenous PACAP in intestines in PACAP
knockout (KO) mice. Warm ischemia–reperfusion injury and cold preservation models
showed that the lack of PACAP caused a higher vulnerability against ischemic
periods. Changes were more severe in PACAP KO mice at all examined time points.
This fi nding was supported by increased levels of oxidative stress markers and
decreased expression of antioxidant molecules. PACAP was proven to be protective
not only in ischemic but also in infl ammatory bowel diseases. A recent study showed
that PACAP treatment prolonged survival of Toxoplasma gondii infected mice suffering
from acute ileitis and was able to reduce the ileal expression of proinfl ammatory
cytokines. We completed the present review with recent clinical results obtained
in patients suffering from infl ammatory bowel diseases. It was found that PACAP
levels were altered depending on the activity, type of the disease, and antibiotic
therapy, suggesting its probable role in infl ammatory events of the intestine
Native diversity buffers against severity of non-native tree invasions
Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies. Here, leveraging global tree databases, we explore how the phylogenetic and functional diversity of native tree communities, human pressure and the environment influence the establishment of non-native tree species and the subsequent invasion severity. We find that anthropogenic factors are key to predicting whether a location is invaded, but that invasion severity is underpinned by native diversity, with higher diversity predicting lower invasion severity. Temperature and precipitation emerge as strong predictors of invasion strategy, with non-native species invading successfully when they are similar to the native community in cold or dry extremes. Yet, despite the influence of these ecological forces in determining invasion strategy, we find evidence that these patterns can be obscured by human activity, with lower ecological signal in areas with higher proximity to shipping ports. Our global perspective of non-native tree invasion highlights that human drivers influence non-native tree presence, and that native phylogenetic and functional diversity have a critical role in the establishment and spread of subsequent invasions
Obesity and Gastroesophageal Reflux: Quantifying the Association Between Body Mass Index, Esophageal Acid Exposure, and Lower Esophageal Sphincter Status in a Large Series of Patients with Reflux Symptoms
Obesity and gastroesophageal reflux disease (GERD) are increasingly important health problems. Previous studies of the relationship between obesity and GERD focus on indirect manifestations of GERD. Little is known about the association between obesity and objectively measured esophageal acid exposure. The aim of this study is to quantify the relationship between body mass index (BMI) and 24-h esophageal pH measurements and the status of the lower esophageal sphincter (LES) in patients with reflux symptoms.
Data of 1,659 patients (50% male, mean age 51 ± 14) referred for assessment of GERD symptoms between 1998 and 2008 were analyzed. These subjects underwent 24-h pH monitoring off medication and esophageal manometry. The relationship of BMI to 24-h esophageal pH measurements and LES status was studied using linear regression and multiple regression analysis. The difference of each acid exposure component was also assessed among four BMI subgroups (underweight, normal weight, overweight, and obese) using analysis of variance and covariance.
Increasing BMI was positively correlated with increasing esophageal acid exposure (adjusted R
2 = 0.13 for the composite pH score). The prevalence of a defective LES was higher in patients with higher BMI (p < 0.0001). Compared to patients with normal weight, obese patients are more than twice as likely to have a mechanically defective LES [OR = 2.12(1.63–2.75)].
An increase in body mass index is associated with an increase in esophageal acid exposure, whether BMI was examined as a continuous or as a categorical variable; 13% of the variation in esophageal acid exposure may be attributable to variation in BMI
A Cost-Effective ELP-Intein Coupling System for Recombinant Protein Purification from Plant Production Platform
BACKGROUND: Plant bioreactor offers an efficient and economical system for large-scale production of recombinant proteins. However, high cost and difficulty in scaling-up of downstream purification of the target protein, particularly the common involvement of affinity chromatography and protease in the purification process, has hampered its industrial scale application, therefore a cost-effective and easily scale-up purification method is highly desirable for further development of plant bioreactor. METHODOLOGY/PRINCIPAL FINDINGS: To tackle this problem, we investigated the ELP-intein coupling system for purification of recombinant proteins expressed in transgenic plants using a plant lectin (PAL) with anti-tumor bioactivity as example target protein and rice seeds as production platform. Results showed that ELP-intein-PAL (EiP) fusion protein formed novel irregular ER-derived protein bodies in endosperm cells by retention of endogenous prolamins. The fusion protein was partially self-cleaved in vivo, but only self-cleaved PAL protein was detected in total seed protein sample and deposited in protein storage vacuoles (PSV). The in vivo uncleaved EiP protein was accumulated up to 2-4.2% of the total seed protein. The target PAL protein could be purified by the ELP-intein system efficiently without using complicated instruments and expensive chemicals, and the yield of pure PAL protein by the current method was up to 1.1 mg/g total seed protein. CONCLUSION/SIGNIFICANCE: This study successfully demonstrated the purification of an example recombinant protein from rice seeds by the ELP-intein system. The whole purification procedure can be easily scaled up for industrial production, providing the first evidence on applying the ELP-intein coupling system to achieve cost-effective purification of recombinant proteins expressed in plant bioreactors and its possible application in industry
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