2,741 research outputs found
Factors affecting sperm recovery rates and survival after centrifugation of equine semen
Conventional centrifugation protocols result in important sperm losses during removal of the supernatant. In this study, the effect of centrifugation force (400 or 900 × g), duration (5 or 10 min), and column height (20 or 40 mL; Experiment 1); sperm concentration (25, 50, and 100 × 10[superscript 6]/mL; Experiment 2), and centrifugation medium (EZ-Mixin CST [Animal Reproduction Systems, Chino, CA, USA], INRA96 [IMV Technologies, Maple Grove, MN, USA], or VMDZ [Partnar Animal Health, Port Huron, MI, USA]; Experiment 3) on sperm recovery and survival after centrifugation and cooling and storage were evaluated. Overall, sperm survival was not affected by the combination of centrifugation protocol and cooling. Total sperm yield was highest after centrifugation for 10 min at 400 × g in 20-mL columns (95.6 ± 5%, mean ± SD) or 900 × g in 20-mL (99.2 ± 0.8%) or 40-mL (91.4 ± 4.5%) columns, and at 900 × g for 5 min in 20-mL columns (93.8 ± 8.9%; P < 0.0001). Total (TMY) and progressively motile sperm yield followed a similar pattern (P < 0.0001). Sperm yields were not significantly different among samples centrifuged at various sperm concentrations. However, centrifugation at 100 × 10[superscript 6]/mL resulted in significantly lower total sperm yield (83.8 ± 10.7%) and TMY (81.7 ± 6.8%) compared with noncentrifuged semen. Centrifugation in VMDZ resulted in significantly lower TMY (69.3 ± 22.6%), progressively motile sperm yield (63.5 ± 18.2%), viable yield (60.9 ± 36.5%), and survival of progressively motile sperm after cooling (21 ± 10.8%) compared with noncentrifuged semen. In conclusion, centrifuging volumes of ≤ 20 mL minimized sperm losses with conventional protocols. With 40-mL columns, it may be recommended to increase the centrifugal force to 900 × g for 10 min and dilute the semen to a sperm concentration of 25 to 50 × 10[superscript 6]/mL in a milk- or fractionated milk-based medium. The semen extender VMDZ did not seem well suited for centrifugation of equine semen
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PPAR<i>γ</i> agonist-loaded PLGA -PEG nanocarriers as a potential treatment for Alzheimer’s disease: in vitro and in vivo studies
Objective: The first aim of this study was to develop a nanocarrier that could transport the peroxisome proliferator-activated receptor agonist, pioglitazone (PGZ) across brain endothelium and examine the mechanism of nanoparticle transcytosis. The second aim was to determine whether these nanocarriers could successfully treat a mouse model of Alzheimer’s disease (AD).
Methods: PGZ-loaded nanoparticles (PGZ-NPs) were synthesized by the solvent displacement technique, following a factorial design using poly (lactic-co-glycolic acid) polyethylene glycol (PLGA-PEG). The transport of the carriers was assessed in vitro, using a human brain endothelial cell line, cytotoxicity assays, fluorescence-tagged nanocarriers, fluorescence-activated cell sorting, confocal and transmission electron microscopy. The effectiveness of the treatment was assessed in APP/PS1 mice in a behavioral assay and by measuring the cortical deposition of β-amyloid.
Results: Incorporation of PGZ into the carriers promoted a 50x greater uptake into brain endothelium compared with the free drug and the carriers showed a delayed release profile of PGZ in vitro. In the doses used, the nanocarriers were not toxic for the endothelial cells, nor did they alter the permeability of the blood–brain barrier model. Electron microscopy indicated that the nanocarriers were transported from the apical to the basal surface of the endothelium by vesicular transcytosis. An efficacy test carried out in APP/PS1 transgenic mice showed a reduction of memory deficit in mice chronically treated with PGZ-NPs. Deposition of β-amyloid in the cerebral cortex, measured by immunohistochemistry and image analysis, was correspondingly reduced.
Conclusion: PLGA-PEG nanocarriers cross brain endothelium by transcytosis and can be loaded with a pharmaceutical agent to effectively treat a mouse model of AD
Characterization of the Taenia spp HDP2 sequence and development of a novel PCR-based assay for discrimination of Taenia saginata from Taenia asiatica
A previously described Taenia saginata HDP2 DNA sequence, a 4-kb polymorphic fragment, was previously used as the basis for developing PCR diagnostic protocols for the species-specific discrimination of T. saginata from T. solium and for the differentiation of T. saginata from T. asiatica. The latter was shown subsequently to lack the required specificity, so we undertook genetic studies of the HDP2 sequence from T. saginata and T. asiatica to determine why, and to develop a novel HDP2-PCR protocol for the simultaneous unambiguous identification of human taeniids. Sequencing and further analysis of the HDP2 DNA fragments of 19 Asiatic isolates of T. saginata and T. asiatica indicated that the HDP2 sequences of both species exhibited clear genomic variability, due to polymorphic variable fragments, that could correspond to the non-transcribed region of ribosomal DNA. This newly observed polymorphism allowed us to develop a novel, reproducible and reliable HDP2-PCR protocol which permitted the simultaneous discrimination of all T. saginata and T. asiatica isolates examined. This species-specific identification was based on, and facilitated by, the clear size difference in amplicon profiles generated: fragments of 1300 bp, 600 bp and 300 bp were produced for T. asiatica, amplicons of 1300 bp and 300 bp being obtained for T. saginata. Control T. solium samples produced one amplicon of 600 bp with the HDP2-PCR protocol. The assay has the potential to prove useful as a diagnostic tool in areas such as South East Asia where T. saginata, T. asiatica and T. solium coexist
Monitorización ambulatoria de la presión arterial (MAPA) en la identificación de patrones circadianos en pacientes con hipertensión arterial: evaluación de seguridad, efectividad y eficiencia
Pressió arterial; Hipertensió arterial; Monitorització ambulatoriaPresión arterial; Hipertensión arterial; Monitorización ambulatoriaBlood pressure; Arterial hypertension; Ambulatory monitoringAmb l’objectiu d’avaluar l’evidència disponible sobre la seguretat, eficàcia/ efectivitat clínica i eficiència dels dispositius de MAPA en pacients adults de 18 anys o més, amb HTA i sospita de patrons circadiaris anormals, com poden ser HTA matutina, HTA diürna, HTA nocturna, hipotensió postprandial, descens tensional nocturn inadequat o augment de la variabilitat tensional a curt termini, es va dur a terme una revisió sistemàtica de la literatura PubMed/Medline, Cochrane Library, Scopus, Web of Science i Trip Database. Les variables de resultat descrites a la literatura que es va incloure i van ser analitzades eren referents a la seguretat. L’eficàcia/efectivitat i l’eficiència de la tecnologia. Els dissenys d’estudis que es van buscar van ser assajos clínics controlats aleatoritzats (ACA), assajos clínics no aleatoritzats, estudis quasiexperimentals, estudis de cohorts, estudis de casos i controls i estudis de cost-efectivitat.Con el objetivo de evaluar la evidencia disponible sobre la seguridad, eficacia/efectividad clínica y eficiencia de los dispositivos de MAPA en pacientes adultos de 18 años o más, con HTA y sospecha de patrones circadianos anormales como la HTA matutina, HTA diurna, HTA nocturna, hipotensión postprandial, descenso tensional nocturno inadecuado o aumento de la variabilidad tensional a corto plazo, se llevó a cabo una revisión sistemática de la literatura PubMed/Medline, Cochrane Library, Scopus, Web of Science y Trip Database. Las variables de resultado descritas en la literatura incluida
que fueron analizadas se referían a la seguridad, la eficacia/efectividad y la eficiencia de la tecnología. Los diseños de estudios que se buscaron fueron ensayos clínicos controlados aleatorizados (ECA), ensayos clínicos no aleatorizados, estudios cuasiexperimentales, estudios de cohortes, estudios de casos y controles y estudios de coste-efectividad.In order to evaluate the evidence available on safety, clinical efficacy/effectiveness, and efficiency of the ABPM devices in adult patients aged 18 years or older with HT and suspected abnormal circadian patterns (such as morning HT, daytime HT, nocturnal HT, postprandial hypotension, inadequate nocturnal dipping in BP or increased short-term BP variability), there was a systematic review on the literature of PubMed/Medline, Cochrane Library, Scopus, Web of Science, and Trip Database. The outcome variables analysed from the literature involved safety, efficacy/effectiveness, and efficiency of
the technology. The preferred study designs were randomised controlled clinical trials (RCTs), non-randomised clinical trials, quasi-experiments, cohort studies, case-control studies, and cost-effective studies
Tenofovir Nephrotoxicity: 2011 Update
Tenofovir is an acyclic nucleotide analogue reverse-transcriptase inhibitor structurally similar to the nephrotoxic drugs adefovir and cidofovir. Tenofovir is widely used to treat HIV infection and approved for treatment of hepatitis B virus. Despite initial cell culture and clinical trials results supporting the renal safety of tenofovir, its clinical use is associated with a low, albeit significant, risk of kidney injury. Proximal tubular cell secretion of tenofovir explains the accumulation of the drug in these mitochondria-rich cells. Tenofovir nephrotoxicity is characterized by proximal tubular cell dysfunction that may be associated with acute kidney injury or chronic kidney disease. Withdrawal of the drug leads to improvement of analytical parameters that may be partial. Understanding the risk factors for nephrotoxicity and regular monitoring of proximal tubular dysfunction and serum creatinine in high-risk patients is required to minimize nephrotoxicity. Newer, structurally similar molecular derivatives that do not accumulate in proximal tubules are under study
Novel CaLB-like Lipase Found Using ProspectBIO, a Software for Genome-Based Bioprospection
Enzymes have been highly demanded in diverse applications such as in the food, pharmaceutical, and industrial fuel sectors. Thus, in silico bioprospecting emerges as an efficient strategy for discovering new enzyme candidates. A new program called ProspectBIO was developed for this purpose as it can find non-annotated sequences by searching for homologs of a model enzyme directly in genomes. Here we describe the ProspectBIO software methodology and the experimental validation by prospecting for novel lipases by sequence homology to Candida antarctica lipase B (CaLB) and conserved motifs. As expected, we observed that the new bioprospecting software could find more sequences (1672) than a conventional similarity-based search in a protein database (733). Additionally, the absence of patent protection was introduced as a criterion resulting in the final selection of a putative lipase-encoding gene from Ustilago hordei (UhL). Expression of UhL in Pichia pastoris resulted in the production of an enzyme with activity towards a tributyrin substrate. The recombinant enzyme activity levels were 4-fold improved when lowering the temperature and increasing methanol concentrations during the induction phase in shake-flask cultures. Protein sequence alignment and structural modeling showed that the recombinant enzyme has high similarity and capability of adjustment to the structure of CaLB. However, amino acid substitutions identified in the active pocket entrance may be responsible for the differences in the substrate specificities of the two enzymes. Thus, the ProspectBIO software allowed the finding of a new promising lipase for biotechnological application without the need for laborious and expensive conventional bioprospecting experimental steps
Evaluación de la seguridad, eficacia/efectividad y eficiencia de la teleconsulta en atención primaria, y de los aspectos organizativos, éticos, sociales y legales ligados a su uso
Atenció primària; Teleconsulta; AvaluacióAtención primaria; Teleconsulta; EvaluaciónPrimary care; Teleconsultation; EvaluationL'atenció primària de salut actualment s’enfronta a una limitació en recursos, sobretot
econòmics i de força de treball. A més, la pandèmia pel coronavirus SARS-CoV-2 (COVID-19) ha posat de manifest més que mai la importància de poder atendre pacients de manera remota (a distància). La teleconsulta (entesa com la comunicació a distància entre professional de la salut i pacient, bé de forma síncrona a través de videotrucada, trucada telefònica o missatgeria instantània, o bé de forma asíncrona a través de correu electrònic en plataformes segures, eConsulta o similar) es planteja com una possible eina que podria ajudar a estalviar recursos econòmics i de disponibilitat de temps a tots els actors que formen part de la cadena de valor, mantenir o millorar la qualitat de l’atenció (resultats en salut) i l’experiència de l’usuari, i garantir la futura viabilitat dels serveis d’atenció primària.La atención primaria de salud se enfrenta actualmente a una limitación en recursos,
sobre todo económicos y de fuerza de trabajo. Además, la pandemia por el coronavirus SARS-CoV-2 (COVID19) ha puesto de manifiesto más que nunca la importancia de poder atender a pacientes de forma remota (a distancia). La teleconsulta (entendida como la comunicación a distancia entre profesional de la salud y paciente, bien de forma síncrona a través de videollamada, llamada telefónica o mensajería instantánea, bien de forma
asíncrona a través de correo electrónico en plataformas seguras, eConsulta o similar) se plantea como una posible herramienta que podría ayudar a ahorrar recursos económicos y de disponibilidad de tiempo a todos los actores que forman parte de la cadena de valor, manteniendo o mejorando la calidad de la atención (resultados en salud) y la experiencia del usuario, y garantizando la viabilidad futura de los servicios de atención primaria.Primary healthcare is currently facing a restriction of available resources, especially
in terms of finances and workforce. In addition, the SARS-CoV-2 coronavirus pandemic (COVID-19) has highlighted more than ever the importance of being able to care for patients remotely. Teleconsultation (understood as remote communication between health professional and patient, either synchronously via video call, telephone
call or instant messaging, or asynchronously via email on secure platforms, eConsultation or similar) is seen as a possible tool that could help save financial resources and time availability for all the actors involved in the value chain, maintaining or improving the quality of care (health outcomes) and the user experience, and guaranteeing
the future viability of primary care services
Cirugía robótica en patología quirúrgica benigna y maligna: urología, cirugía general y digestiva, cirugía cardiotorácica, ginecología, endocrinología, oftalmología y cirugía de cabeza y cuello. Capítulo II: cirugía urológica, ginecológica, general y digestiva
Cirurgia robòtica; Tècniques quirúrgiques; InnovacióCirugía robótica; Técnicas quirúrgicas; InnovaciónRobotic surgery; Surgical techniques; InnovationS'ha avaluat, de manera específica, l’eficàcia o l’efectivitat, la seguretat i l’eficiència de la cirurgia assistida per robot en comparació amb la cirurgia oberta o la cirurgia laparoscòpica en un grup d’indicacions de patologia benigna o maligna en les especialitats de cirurgia urològica, ginecològica i general i digestiva. De manera addicional, s’ha analitzat l’activitat de la cirurgia robòtica a Espanya per a les indicacions ginecològiques en els últims cinc anys.Se ha evaluado, de forma específica, la eficacia o la efectividad, la seguridad y la eficiencia de la cirugía asistida por robot en comparación con la cirugía abierta o la cirugía laparoscópica en un grupo de indicaciones de patología benigna o maligna en las especialidades de cirugía urológica, ginecológica y general y digestiva. De forma adicional, se ha analizado la actividad de la cirugía robótica en España para las indicaciones ginecológicas en los últimos cinco años.The aim of the study is to determine whether robot-assisted surgery has sufficient evidence to be included in the common portfolio of the UK NHS healthcare services. To this end, the efficacy or effectiveness, safety and efficiency of robot-assisted surgery compared to open surgery or laparoscopic surgery in a group of indications of benign or malignant pathology in the specialities of urological, gynaecological and general and digestive surgery has been specifically evaluated. In addition, the activity of robotic surgery in Spain for gynaecological indications in the last five years has been analysed.Este documento ha sido realizado por la Agència de Qualitat i Avaluació Sanitàries de Catalunya en el marco de la financiación del Ministerio de Sanidad para el desarrollo de las actividades del Plan anual de Trabajo de la Red Española de Agencias de Evaluación de Tecnologías Sanitarias y Prestaciones del SNS, aprobado en el Pleno del Consejo Interterritorial del SNS de 28 de octubre de 2020 (conforme al Acuerdo del Consejo de Ministros de 9 de diciembre de 2020)
Determination of the b quark mass at the M_Z scale with the DELPHI detector at LEP
An experimental study of the normalized three-jet rate of b quark events with
respect to light quarks events (light= \ell \equiv u,d,s) has been performed
using the CAMBRIDGE and DURHAM jet algorithms. The data used were collected by
the DELPHI experiment at LEP on the Z peak from 1994 to 2000. The results are
found to agree with theoretical predictions treating mass corrections at
next-to-leading order. Measurements of the b quark mass have also been
performed for both the b pole mass: M_b and the b running mass: m_b(M_Z). Data
are found to be better described when using the running mass. The measurement
yields: m_b(M_Z) = 2.85 +/- 0.18 (stat) +/- 0.13 (exp) +/- 0.19 (had) +/- 0.12
(theo) GeV/c^2 for the CAMBRIDGE algorithm. This result is the most precise
measurement of the b mass derived from a high energy process. When compared to
other b mass determinations by experiments at lower energy scales, this value
agrees with the prediction of Quantum Chromodynamics for the energy evolution
of the running mass. The mass measurement is equivalent to a test of the
flavour independence of the strong coupling constant with an accuracy of 7
permil.Comment: 24 pages, 10 figures, Accepted by Eur. Phys. J.
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