609 research outputs found
Harvest Tissue Source Does Not Alter the Protective Power of Stromal Cell Therapy Following Intestinal Ischemia and Reperfusion Injury
Background
Transplantation of mesenchymal stromal cells (MSCs) may be a novel treatment for intestinal ischemia. The optimal stromal cell source that could yield maximal protection following injury, however, has not been identified. We hypothesized that: 1) MSCs would increase survival and mesenteric perfusion, preserve intestinal histological architecture, and limit inflammation following intestinal ischemia and reperfusion injury (I/R), and 2) MSCs harvested from different sources of tissue would have equivalent protective properties to the intestine following I/R.
Methods
Adult male mice were anesthetized and a midline laparotomy performed. The intestines were eviscerated, the small bowel mesenteric root identified, and baseline intestinal perfusion was determined using Laser Doppler Imaging (LDI). Intestinal ischemia was established by temporarily occluding the superior mesenteric artery for 60 minutes with a non-crushing clamp. Following ischemia, the clamp was removed and the intestines were allowed to recover. Prior to abdominal closure, 2 × 106 human umbilical (USCs), bone-marrow (BMSCs) derived MSCs, or keratinocytes in 250μl of phosphate-buffered saline (PBS) vehicle were injected into the peritoneum. Animals were allowed to recover for 12 or 24 hours (perfusion, histology, inflammatory studies), or 7 days (survival studies). Survival data was analyzed using log rank test. Perfusion was expressed as percentage of baseline and 12 and 24 hour data was analyzed using one way ANOVA and student’s t-test. Non parametric data was compared using Mann-Whitney-U test. A p-value of less than 0.05 was significant.
Results
All MSCs increased seven day survival following I/R and were superior to vehicle or keratinocytes (P<0.05). All MSCs increased mesenteric perfusion above vehicle at 12 and 24 hours following injury (P<0.05). All MSCs provided superior perfusion compared to keratinocytes at 24 hours post-injury (P<0.05). Administration of each MSC line improved intestinal histology after I/R (P<0.05). Multiple pro-inflammatory chemokines were down-regulated following application of MSCs suggesting a decreased inflammatory response following MSC therapy.
Conclusion
Transplantation of MSCs following intestinal I/R, irrespective of source tissue, significantly increases survival and mesenteric perfusion while limiting intestinal damage and inflammation. Further studies are needed to identify the mechanism that these cells utilize to promote improved outcomes following injury
Exoplanet Diversity in the Era of Space-based Direct Imaging Missions
This whitepaper discusses the diversity of exoplanets that could be detected
by future observations, so that comparative exoplanetology can be performed in
the upcoming era of large space-based flagship missions. The primary focus will
be on characterizing Earth-like worlds around Sun-like stars. However, we will
also be able to characterize companion planets in the system simultaneously.
This will not only provide a contextual picture with regards to our Solar
system, but also presents a unique opportunity to observe size dependent
planetary atmospheres at different orbital distances. We propose a preliminary
scheme based on chemical behavior of gases and condensates in a planet's
atmosphere that classifies them with respect to planetary radius and incident
stellar flux.Comment: A white paper submitted to the National Academy of Sciences Exoplanet
Science Strateg
An empirical approach towards the efficient and optimal production of influenza-neutralizing ovine polyclonal antibodies demonstrates that the novel adjuvant CoVaccine HT(TM) is functionally superior to Freund's adjuvant
Passive immunotherapies utilising polyclonal antibodies could have a valuable role in preventing and treating infectious diseases such as influenza, particularly in pandemic situations but also in immunocompromised populations such as the elderly, the chronically immunosuppressed, pregnant women, infants and those with chronic diseases. The aim of this study was to optimise current methods used to generate ovine polyclonal antibodies. Polyclonal antibodies to baculovirus-expressed recombinant influenza haemagglutinin from A/Puerto Rico/8/1934 H1N1 (PR8) were elicited in sheep using various immunisation regimens designed to investigate the priming immunisation route, adjuvant formulation, sheep age, and antigen dose, and to empirically ascertain which combination maximised antibody output. The novel adjuvant CoVaccine HT™ was compared to Freund’s adjuvant which is currently the adjuvant of choice for commercial production of ovine polyclonal Fab therapies. CoVaccine HT™ induced significantly higher titres of functional ovine anti-haemagglutinin IgG than Freund’s adjuvant but with fewer side effects, including reduced site reactions. Polyclonal hyperimmune sheep sera effectively neutralised influenza virus in vitro and, when given before or after influenza virus challenge, prevented the death of infected mice. Neither the age of the sheep nor the route of antigen administration appeared to influence antibody titre. Moreover, reducing the administrated dose of haemagglutinin antigen minimally affected antibody titre. Together, these results suggest a cost effective way of producing high and sustained yields of functional ovine polyclonal antibodies specifically for the prevention and treatment of globally significant diseases.Natalie E. Stevens, Cara K. Fraser, Mohammed Alsharifi, Michael P. Brown, Kerrilyn R. Diener, John D. Haybal
Consumption of an Anthocyanin-Rich Extract Made From New Zealand Blackcurrants Prior to Exercise May Assist Recovery From Oxidative Stress and Maintains Circulating Neutrophil Function: A Pilot Study
Aim: To evaluate blackcurrant anthocyanin-rich extract (BAE) consumption on time- and dose-dependent plasma anthocyanin bioavailability and conduct a pilot study to explore the potential effect of BAE in promoting recovery from exercise-induced oxidative stress, and maintenance of circulating neutrophil function.Methods: Time- and dose-dependent blackcurrant anthocyanin bioavailability was assessed using LC-MS in 12 participants over 6 h after the ingestion of a placebo or BAE containing 0.8, 1.6, or 3.2 mg/kg total anthocyanins. In a separate pilot intervention exercise trial, 32 participants consumed either a placebo or 0.8, 1.6, or 3.2 mg/kg BAE (8 individuals per group), and then 1 h later performed a 30 min row at 70% VO2max. Blood was collected during the trial for oxidative, antioxidant, inflammatory, and circulating neutrophil status.Results: Consumption of BAE caused a time- and dose-dependent increase in plasma anthocyanins, peaking at 2 h after ingestion of 3.2 mg/kg BAE (217 ± 69 nM). BAE consumed 1 h prior to a 30 min row had no effect on plasma antioxidant status but hastened the recovery from exercise-induced oxidative stress: By 2 h recovery, consumption of 1.6 mg/kg BAE prior to exercise caused a significant (P < 0.05) 34 and 32% decrease in post-exercise plasma oxidative capacity and protein carbonyl levels, respectively, compared to placebo. BAE consumption prior to exercise dose-dependently attenuated a small, yet significant (P < 0.01) transient 13 ± 2% decline in circulating neutrophils observed in the placebo group immediately post-exercise. Furthermore, the timed consumption of either 1.6 or 3.2 mg/kg BAE attenuated a 17 ± 2.4% (P < 0.05) decline in neutrophil phagocytic capability of opsonised FITC-Escherichia coli observed 6 h post-exercise in the placebo group. Similarly, a dose-dependent increase in neutrophil surface expression of complement receptor-3 complex (CR3, critical for effective phagocytosis of opsonised microbes), was observed 6 h post-exercise in both 1.6 and 3.2 mg/kg BAE intervention groups.Conclusions: Consumption of BAE (>1.6 mg/kg) 1 h prior to exercise facilitated recovery from exercise-induced oxidative stress and preserved circulating neutrophil function. This study provides data to underpin a larger study designed to evaluate the efficacy of timed BAE consumption on post-exercise recovery and innate immunity
Relation between therapeutic response and side effects induced by methylphenidate as observed by parents and teachers of children with ADHD
<p>Abstract</p> <p>Background</p> <p>The desired (therapeutic) and undesired (side) effects of methylphenidate might have underlying correlations. The aim of this study was to explore the strength and the possible sources of these correlations.</p> <p>Methods</p> <p>One hundred and fifty-seven children with ADHD (6-12 years) were administered placebo and methylphenidate (0.5 mg/kg in a divided b.i.d. dose), each for a one-week period, in a double-blind, crossover trial. Therapeutic response was assessed using the Conners' Global Index for parents (CGI-Parents) and teachers (CGI-Teachers), while side effects were assessed using the Barkley Side Effects Rating Scale (SERS).</p> <p>Results</p> <p>The side effect profile as assessed by the SERS was similar to that of previous studies with insomnia, decreased appetite, and headaches showing significant treatment effects (p < 0.005). These "somatic/physical" side effects did not correlate with CGI-Parents or CGI-Teachers. However, the side effects of "irritability", "proneness to crying", and "anxiousness" showed significant relationships with CGI-Parents. These "mood/anxiety" side effects showed no significant correlations with the CGI-Teachers.</p> <p>Conclusion</p> <p>The greater "mood/anxiety" side effects on methylphenidate and placebo, the less the parents observe improvement of their children while treated with methylphenidate. This suggests that the correlations between "mood/anxiety" side effects and poor response to treatment may be driven by observer effects rather than biological commonalities between therapeutic and side effects of methylphenidate.</p
The Need for Laboratory Measurements and Ab Initio Studies to Aid Understanding of Exoplanetary Atmospheres
We are now on a clear trajectory for improvements in exoplanet observations
that will revolutionize our ability to characterize their atmospheric
structure, composition, and circulation, from gas giants to rocky planets.
However, exoplanet atmospheric models capable of interpreting the upcoming
observations are often limited by insufficiencies in the laboratory and
theoretical data that serve as critical inputs to atmospheric physical and
chemical tools. Here we provide an up-to-date and condensed description of
areas where laboratory and/or ab initio investigations could fill critical gaps
in our ability to model exoplanet atmospheric opacities, clouds, and chemistry,
building off a larger 2016 white paper, and endorsed by the NAS Exoplanet
Science Strategy report. Now is the ideal time for progress in these areas, but
this progress requires better access to, understanding of, and training in the
production of spectroscopic data as well as a better insight into chemical
reaction kinetics both thermal and radiation-induced at a broad range of
temperatures. Given that most published efforts have emphasized relatively
Earth-like conditions, we can expect significant and enlightening discoveries
as emphasis moves to the exotic atmospheres of exoplanets.Comment: Submitted as an Astro2020 Science White Pape
Efficacy of nonsurgical interventions for anterior knee pain: Systematic review and meta-analysis of randomized trials
Anterior knee pain is a chronic condition that presents frequently to sports medicine clinics, and can have a long-term impact on participation in physical activity. Conceivably, effective early management may prevent chronicity and facilitate physical activity. Although a variety of nonsurgical interventions have been advocated, previous systematic reviews have consistently been unable to reach conclusions to support their use. Considering a decade has lapsed since publication of the most recent data in these reviews, it is timely to provide an updated synthesis of the literature to assist sports medicine practitioners in making informed, evidence-based decisions. A systematic review and meta-analysis was conducted to evaluate the evidence for nonsurgical interventions for anterior knee pain
Utilizing high-throughput experimentation to enhance specific productivity of an E.coli T7 expression system by phosphate limitation
<p>Abstract</p> <p>Background</p> <p>The specific productivity of cultivation processes can be optimized, amongst others, by using genetic engineering of strains, choice of suitable host/vector systems or process optimization (e.g. choosing the right induction time). A further possibility is to reduce biomass buildup in favor of an enhanced product formation, e.g. by limiting secondary substrates in the medium, such as phosphate. However, with conventional techniques (e.g. small scale cultivations in shake flasks), it is very tedious to establish optimal conditions for cell growth and protein expression, as the start of protein expression (induction time) and the degree of phosphate limitation have to be determined in numerous concerted, manually conducted experiments.</p> <p>Results</p> <p>We investigated the effect of different induction times and a concurrent phosphate limitation on the specific productivity of the T7 expression system <it>E.coli </it>BL21(DE3) pRhotHi-2-EcFbFP, which produces the model fluorescence protein EcFbFP upon induction. Therefore, specific online-monitoring tools for small scale cultivations (RAMOS, BioLector) as well as a novel cultivation platform (Robo-Lector) were used for rapid process optimization. The RAMOS system monitored the oxygen transfer rate in shake flasks, whereas the BioLector device allowed to monitor microbial growth and the production of EcFbFP in microtiter plates. The Robo-Lector is a combination of a BioLector and a pipetting robot and can conduct high-throughput experiments fully automated. By using these tools, it was possible to determine the optimal induction time and to increase the specific productivity for EcFbFP from 22% (for unlimited conditions) to 31% of total protein content of the <it>E.coli </it>cells via a phosphate limitation.</p> <p>Conclusions</p> <p>The results revealed that a phosphate limitation at the right induction time was suitable to redirect the available cellular resources during cultivation to protein expression rather than in biomass production. To our knowledge, such an effect was shown for the first time for an IPTG-inducible expression system. Finally, this finding and the utilization of the introduced high-throughput experimentation approach could help to find new targets to further enhance the production capacity of recombinant <it>E.coli</it>-strains.</p
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