420 research outputs found
LOCAL COOPERATIVES' EVALUATION OF BUSINESS INVESTMENT OPPORTUNITIES
Agricultural cooperatives have been restructuring, by way of mergers, acquisitions, joint-ventures, and strategic alliances, to increase efficiencies to remain competitive in a changing business environment. The research evaluating the reorganization of cooperatives has revealed that less than one-half of the restructured businesses are financially successful. There is the potential to significantly influence the future health of the cooperative business sector if, first, insights can be gained concerning the factors being considered by cooperative managers when making restructuring decisions and, second, extension education programs can be adapted to meet the greatest need. In this study we examine: (a) what methods of valuation cooperatives are using when evaluating new business opportunities, and (b) what factors influence the methods of valuation preferred by cooperatives when evaluating new business opportunities.capital budgeting methods, cooperatives, finance, restructuring, Agribusiness,
RVG29-Functionalized Lipid Nanoparticles for Quercetin Brain Delivery and Alzheimers Disease
Purpose: Lipid nanoparticles (SLN and NLC) were functionalized with the RVG29 peptide in order to target the brain and increase the neuronal uptake through the nicotinic acetylcholine receptors. These nanosystems were loaded with quercetin to take advantage of its neuroprotective properties mainly for Alzheimer's disease. Methods: The functionalization of nanoparticles with RVG29 peptide was confirmed by NMR and FTIR. Their morphology was assessed by transmission electron microscopy and nanoparticles size, polydispersity and zeta potential were determined by dynamic light scattering. The in vitro validation tests were conducted in hCMEC/D3 cells, a human blood-brain barrier model and thioflavin T binding assay was conducted to assess the process of amyloid-beta peptide fibrillation typical of Alzheimer's disease. Results: RVG29-nanoparticles displayed spherical morphology and size below 250 nm, which is compatible with brain applications. Zeta potential values were between −20 and −25 mV. Quercetin entrapment efficiency was generally higher than 80% and NLC nanoparticles were able to encapsulate up to 90%. The LDH assay showed that there is no cytotoxicity in hCMEC/D3 cell line and RVG29-nanoparticles clearly increased in 1.5-fold the permeability across the in vitro model of blood-brain barrier after 4 h of incubation compared with non-functionalized nanoparticles. Finally, this nanosystem was capable of inhibiting amyloid-beta aggregation in thioflavin T binding assay, suggesting its great potential for neuroprotection. Conclusions: RVG29-nanoparticles that simultaneously target the blood-brain barrier and induce neurons protection against amyloid-beta fibrillation proved to be an efficient way of quercetin delivery and a promising strategy for future approaches in Alzheimer's disease. [Figure not available: see fulltext.]. (c) 2020, Springer Science+Business Media, LLC, part of Springer Nature
Association between Human T-Cell Lymphotropic Virus Type 1 and 2 (HTLV 1/2) infection and tuberculosis: systematic review and meta-analysis
Background
HTLV-1 infection alters the immune function and
increases the risk of several infectious diseases. In this
meta-analysis, we assess the association between HTLV-
1/2 and active tuberculosis (TB).
Methods
Four databases were searched for relevant articles that
describe the frequency of HTLV- 1/2 infection among
TB patients and control groups of healthy individuals or
patients without a history of TB. Data were analyzed
using the EasyMA software.
Results
The search yielded two hundred and eight articles. Six
met the inclusion criteria and were included in the
meta-analysis. The estimated relative risk of HTLV- 1/2
infection in TB patients was 3.25 times higher than in
the population based control groups.
Conclusion
Patients with active TB have a higher risk of HTLV- 1/2
infection. Prospective studies involving latent tuberculosis
infection (LTBI) in HTLV-1-infected individuals are
necessary to evaluate the potential benefit of TB
chemoprophylaxis
Targeting p53 for melanoma treatment: counteracting tumour proliferation, dissemination and therapeutic resistance
Melanoma is the deadliest form of skin cancer, primarily due to its high metastatic propensity and therapeutic resistance in advanced stages. The frequent inactivation of the p53 tumour suppressor protein in melanomagenesis may predict promising outcomes for p53 activators in melanoma therapy. Herein, we aimed to investigate the antitumor potential of the p53-activating agent SLMP53-2 against melanoma. Two- and three-dimensional cell cultures and xenograft mouse models were used to unveil the antitumor activity and the underlying molecular mechanism of SLMP53-2 in melanoma. SLMP53-2 inhibited the growth of human melanoma cells in a p53-dependent manner through induction of cell cycle arrest and apoptosis. Notably, SLMP53-2 induced p53 stabilization by disrupting the p53–MDM2 interaction, enhancing p53 transcriptional activity. It also promoted the expression of p53-regulated microRNAs (miRNAs), including miR-145 and miR-23a. Moreover, it displayed anti-invasive and antimigratory properties in melanoma cells by inhibiting the epithelial-to-mesenchymal transition (EMT), angiogenesis and extracellular lactate production. Importantly, SLMP53-2 did not induce resistance in melanoma cells. Additionally, it synergized with vemurafenib, dacarbazine and cisplatin, and resensitized vemurafenib-resistant cells. SLMP53-2 also exhibited antitumor activity in human melanoma xenograft mouse models by repressing cell proliferation and EMT while stimulating apoptosis. This work discloses the p53-activating agent SLMP53-2 which has promising therapeutic potential in advanced melanoma, either as a single agent or in combination therapy. By targeting p53, SLMP53-2 may counteract major features of melanoma aggressiveness.This work received financial support from PT national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through
LAQV/REQUIMTE (UID/QUI/50006/2020), iMed.ULisboa (UIDB/04138/2020), and PTDC/QUIQOR/29664/2017, PTDC/MEC-ONC/32018/2017. We thank FCT for the fellowships SFRH/BD/
128673/2017 (J. Loureiro), 2020.04613.BD (J. Calheiros), PD/BD/143126/2019 (V. Barcherini)
Genetic history of Hepatitis C virus in Venezuela: high diversity and long time of evolution of HCV genotype 2
Background: The subtype diversity of the hepatitis C virus (HCV) genotypes is unknown in Venezuela. Methodology/Principal Findings: Partial sequencing of the NS5B region was performed in 310 isolates circulating in patients from 1995 to 2007. In the samples collected between 2005 and 2007, HCV genotype 1 (G1) was the most common genotype (63%), composed as expected of mainly G1a and G1b. G2 was the second most common genotype (33%), being G2a almost absent and G2j the most frequent subtype. Sequence analysis of the core region confirmed the subtype assignment performed within the NS5b region in 63 isolates. The complete genome sequence of G2j was obtained. G2j has been described in France, Canada and Burkina Fasso, but it was not found in Martinique, where several subtypes of G2 circulate in the general population. Bayesian coalescence analysis indicated a most recent common ancestor (MRCA) of G2j around 1785, before the introduction of G1b (1869) and G1a (1922). While HCV G1a and G1b experienced a growth reduction since 1990, coincident with the time when blood testing was implemented in Venezuela, HCV G2j did not seem to reach growth equilibrium during this period. Conclusions/Significance: Assuming the introduction of G2j from Africa during the slave trade, the high frequency of G2j found in Venezuela could suggest: 1- the introduction of African ethnic groups different from the ones introduced to Martinique or 2- the occurrence of a founder effect. This study represents an in-depth analysis of the subtype diversity of HCV in Venezuela, which is still unexplored in the Americas and deserves further studies.Fil: Sulbarán, Maria Z.. Instituto Venezolano de Investigaciones Cientificas; VenezuelaFil: Di Lello, Federico Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Virología; ArgentinaFil: Sulbarán, Yoneira. Instituto Venezolano de Investigaciones Cientificas; VenezuelaFil: Cosson, Clarisa. Instituto Venezolano de Investigaciones Cientificas; VenezuelaFil: Loureiro, Carmen. Instituto Venezolano de Investigaciones Cientificas; VenezuelaFil: Rangel, Héctor R.. Instituto Venezolano de Investigaciones Cientificas; VenezuelaFil: Cantaloube, Jean F.. Etablissement Français du Sang Alpes-Méditerranée. Unité Emergence et Co-évolution virale; FranciaFil: Campos, Rodolfo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Virología; ArgentinaFil: Moratorio, Gonzalo. Universidad de la Republica; Uruguay. Instituto Pasteur de Montevideo; UruguayFil: Cristina, Juan. Universidad de la Republica; UruguayFil: Pujol, Flor H.. Instituto Venezolano de Investigaciones Cientificas; Venezuel
Immobilization of L-asparaginase towards surface-modified carbon nanotubes
L-asparaginase (LA) is an enzyme that catalyzes L-asparagine hydrolysis into L-aspartic
acid and ammonia and is mainly applied in pharmaceutical and food industries. The LA
currently commercialized for pharmaceutical purposes is produced from two main
bacterial sources: recombinant Escherichia coli and Erwinia chrysanthemi. However,
some disadvantages are associated with its free form, such as the shorter half-life.
Immobilization of LA has been proposed as an efficient approach to overcome this
limitation. In this work, a straightforward method, including the functionalization of
multi-walled carbon nanotubes (MWCNTs) through a hydrothermal oxidation treatment
and the immobilization of LA by adsorption over pristine and modified MWCNTs was
investigated. Different operation conditions, including pH, contact time,
ASNase/MWCNT mass ratio, and the operational stability of the immobilized LA, were
evaluated. The characterization of the LA-MWCNT bioconjugate was addressed using
different techniques, namely Transmission Electron Microscopy (TEM),
Thermogravimetric analysis (TGA), and Raman spectroscopy. Functionalized MWCNTs showed promising results, with an immobilization yield and a relative recovered activity
of commercial LA above 95%, under the optimized adsorption conditions (pH 8, 60 min
of contact, and 1.510–3
g.mL-1
of LA). The LA-MWCNT bioconjugate also showed
improved enzyme operational stability (6 consecutive reaction cycles without activity
loss), proving its suitability for application in industrial processes.publishe
Immobilization of L-asparaginase towards surface-modified carbon nanotubes
L-asparaginase (ASNase, EC 3.5.1.1) is an enzyme that catalyzes L-asparagine hydrolysis into L-aspartic acid and
ammonia and is mainly applied in pharmaceutical and food industries [1]. The ASNase currently commercialized for pharmaceutical purposes is produced from two main bacterial sources: recombinant Escherichia coli
and Erwinia chrysanthemi. However, some disadvantages are associated with its free form, such as the shorter
half-life [2]. Immobilization of ASNase has been proposed as an efficient approach to overcome this limitation
[3]. In this work, a straightforward method, including the functionalization of multi-walled carbon nanotubes
(MWCNTs) through a hydrothermal oxidation treatment with nitric acid, and the immobilization of ASNase
by adsorption over pristine and modified MWCNTs was investigated. Different operation conditions, including pH, contact time, ASNase/MWCNT mass ratio, and the operational stability of the immobilized ASNase were
evaluated. The characterization of the ASNase-MWCNT bioconjugate was addressed using different techniques,
namely Transmission Electron Microscopy (TEM), Thermogravimetric analysis (TGA), and Raman spectroscopy.
Functionalized MWCNTs showed promising results, with an immobilization yield and a relative recovered activity of commercial ASNase above 95%, under the optimized adsorption conditions (pH 8, 60 min of contact
and 1.5´10–3 g.mL-1of ASNase). The ASNase-MWCNT bioconjugate also showed improved enzyme operational
stability (6 consecutive reaction cycles without activity loss), proving its suitability for application in industrial
processes.publishe
Superior operational stability of immobilized L-asparaginase over surface-modified carbon nanotubes
L-asparaginase (ASNase, EC 3.5.1.1) is an enzyme that catalyzes the L-asparagine hydrolysis into L-aspartic acid and ammonia, being mainly applied in pharmaceutical and food industries. However, some disadvantages are associated with its free form, such as the ASNase short half-life, which may be overcome by enzyme immobilization. In this work, the immobilization of ASNase by adsorption over pristine and modified multi-walled carbon nanotubes (MWCNTs) was investigated, the latter corresponding to functionalized MWCNTs through a hydrothermal oxidation treatment. Different operating conditions, including pH, contact time and ASNase/MWCNT mass ratio, as well as the operational stability of the immobilized ASNase, were evaluated. For comparison purposes, data regarding the ASNase immobilization with pristine MWCNT was detailed. The characterization of the ASNase-MWCNT bioconjugate was addressed using different techniques, namely Transmission Electron Microscopy (TEM), Thermogravimetric Analysis (TGA) and Raman spectroscopy. Functionalized MWCNTs showed promising results, with an immobilization yield and a relative recovered activity of commercial ASNase above 95% under the optimized adsorption conditions (pH 8, 60 min of contact and 1.5 × 10-3 g mL-1 of ASNase). The ASNase-MWCNT bioconjugate also showed improved enzyme operational stability (6 consecutive reaction cycles without activity loss), paving the way for its use in industrial processes.publishe
The usefulness of contrast during exercise echocardiography for the assessment of systolic pulmonary pressure
<p>Abstract</p> <p>Background</p> <p>The systolic pulmonary artery pressure (PAPs) can be accurately estimated, non-invasively, using continuous-wave Doppler (CWD) ultrasound measurement of the peak velocity of a tricuspid regurgitant (TR) jet.</p> <p>However, it is often difficult to obtain adequate tricuspid regurgitation signals for measurement of PAPs, what could lead to its underestimation. Therefore, utilization of air-blood-saline contrast has been implemented for the improvement of Doppler signal in several clinical contexts.</p> <p>It is now recommended in the evaluation of patients with pulmonary hypertension. Physical activity is severely restricted in patients with PAH, being exertional dypnea the most typical symptom. Exercise stress echo-Doppler imaging allows assessment of the response to exercise. It is an excellent screening test for patients with suspected PAH. Our purpose was to evaluate the value and accuracy of agitated saline with blood contrast echocardiography, in the improvement of the Doppler signal, to quantify PAPs during treadmill exercise-echocardiography.</p> <p>Purpose</p> <p>To evaluate the value of contrast echocardiography, using agitated saline with blood, in the improvement of the Doppler signal used to quantify the pulmonary artery systolic pressure during exercise.</p> <p>Methods</p> <p>From a total of 41 patients (pts), we studied 38 pts (93%), 35 women, aged 54 ± 12 years-old. 27 with the diagnosis of systemic sclerosis, 10 with history of pulmonary embolism and one patient with a suspected idiopathic PAH, who were referred to the Unity of Heart Failure and Pulmonary Hypertension for screening of PAH. According to the Unity protocol, a transthoracic echocardiogram was made, in left decubitus (LD), with evaluation of right ventricle-right atria gradient (RV/RAg). A peripheral venous access was obtained, with a 3-way stopcock and the patients were placed in orthostatism (O), with a new evaluation of RV/RAg. Exercise echocardiography (EE) was begun, with evaluation of RV/RAg at peak exercise (P) and afterwards agitated saline (8 cc with 1 cc of air and 1 cc of blood) was injected, followed by a new evaluation of RV/RAg (PC) and then the interruption of the EE. Pulmonary Hypertension was diagnosed when RV/RAg at the end of the exercise was superior to 40 mmHg.</p> <p>Results</p> <p>The quality of Doppler signal was deteriorated in 5 pts, maintained in 6 pts and improved in 26 pts, with the use of contrast. In one patient, an interventricular septal defect was diagnosed. In 6 pts, a Doppler signal was only obtained with the use of contrast. In 15 pts, a RV/RAg superior to 40 mmHg was only obtained with the use of contrast. Of these, 9 have already been submitted to right heart cathetherism, that confirmed the diagnosis of pulmonary hypertension in 5 of them (56%). RV/RAg (P) was 44 ± 11 mmHg and RV/RAg (PC) was 54 ± 11 mmHg, p < 0,001.</p> <p>Conclusion</p> <p>1. The method is applicable in a large number of patients. 2. RV/RA gradients obtained at peak exercise are higher with the use of contrast, and the clinical meaning of this difference should be evaluated in a larger number of pts submitted to right heart cathetherism. The high number of false positives should lead to a higher diagnostic threshold. 3. This method seems to have relevant clinical value in the diagnosis of pulmonary arterial hypertension.</p
How should we define health?
The WHO definition of health as complete wellbeing is no longer fit for purpose given the rise of
chronic disease. Machteld Huber and colleagues propose changing the emphasis towards the
ability to adapt and self manage in the face of social, physical, and emotional challenge
- …