In a trial evaluating two daily-dose levels of voxelotor, which binds to sickle hemoglobin and prevents polymerization under hypoxic conditions, hemoglobin levels increased by more than 1 g per ...deciliter in approximately half the patients who received the drug, and markers of hemolysis decreased. Toxic effects were mainly low grade and not different from those with placebo.
In a randomized trial involving more than 2000 patients, transcatheter aortic-valve replacement was noninferior to surgical replacement in the primary end point of death from any cause or disabling ...stroke at 2 years.
Transcatheter aortic-valve replacement (TAVR) is a new therapy for patients with severe aortic stenosis who are not candidates for surgery
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or who are at high risk for complications due to surgery.
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The acceptance of the use of TAVR in high-risk patients was based on evidence from clinical trials
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that used early-generation TAVR devices; these procedures were associated with considerable procedure-related complications.
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Recently, increased operator experience and enhanced transcatheter valve systems have led to a worldwide trend to use TAVR in patients who are at low or intermediate risk.
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This trend has been evaluated in small . . .
Toxoplasma gondii has become a model for studying the phylum Apicomplexa, in part due to the availability of excellent genetic tools. Although reverse genetic tools are available in a few widely ...utilized laboratory strains, they rely on special genetic backgrounds that are not easily implemented in natural isolates. Recent progress in modifying CRISPR (clustered regularly interspaced short palindromic repeats), a system of DNA recognition used as a defense mechanism in bacteria and archaea, has led to extremely efficient gene disruption in a variety of organisms. Here we utilized a CRISPR/CAS9-based system with single guide RNAs to disrupt genes in T. gondii. CRISPR/CAS9 provided an extremely efficient system for targeted gene disruption and for site-specific insertion of selectable markers through homologous recombination. CRISPR/CAS9 also facilitated site-specific insertion in the absence of homology, thus increasing the utility of this approach over existing technology. We then tested whether CRISPR/CAS9 would enable efficient transformation of a natural isolate. Using CRISPR/CAS9, we were able to rapidly generate both rop18 knockouts and complemented lines in the type I GT1 strain, which has been used for forward genetic crosses but which remains refractory to reverse genetic approaches. Assessment of their phenotypes in vivo revealed that ROP18 contributed a greater proportion to acute pathogenesis in GT1 than in the laboratory type I RH strain. Thus, CRISPR/CAS9 extends reverse genetic techniques to diverse isolates of T. gondii, allowing exploration of a much wider spectrum of biological diversity.
Genetic approaches have proven very powerful for studying the biology of organisms, including microbes. However, ease of genetic manipulation varies widely among isolates, with common lab isolates often being the most amenable to such approaches. Unfortunately, such common lab isolates have also been passaged frequently in vitro and have thus lost many of the attributes of wild isolates, often affecting important traits, like virulence. On the other hand, wild isolates are often not amenable to standard genetic approaches, thus limiting inquiry about the genetic basis of biological diversity. Here we imported a new genetic system based on CRISPR/CAS9, which allows high efficiency of targeted gene disruption in natural isolates of T. gondii. This advance promises to bring the power of genetics to bear on the broad diversity of T. gondii strains that have been described recently.
In living cells, microtubules (MTs) play pleiotropic roles, which require very different mechanical properties. Unlike the dynamic MTs found in the cytoplasm of metazoan cells, the specialized ...cortical MTs from Toxoplasma gondii, a prevalent human pathogen, are extraordinarily stable and resistant to detergent and cold treatments. Using single-particle cryo-EM, we determine their ex vivo structure and identify three proteins (TrxL1, TrxL2 and SPM1) as bona fide microtubule inner proteins (MIPs). These three MIPs form a mesh on the luminal surface and simultaneously stabilize the tubulin lattice in both longitudinal and lateral directions. Consistent with previous observations, deletion of the identified MIPs compromises MT stability and integrity under challenges by chemical treatments. We also visualize a small molecule like density at the Taxol-binding site of β-tubulin. Our results provide the structural basis to understand the stability of cortical MTs and suggest an evolutionarily conserved mechanism of MT stabilization from the inside.
The chronic coronary syndromes (CCS) include patients with a classic history of angina pectoris in the presence of either risk factors for or known atherosclerotic coronary artery disease. ...Randomized, controlled trials conducted in the optimal medical therapy (OMT) era have convincingly demonstrated that adherence to the outdated paradigm focused on treatment of obstructive coronary disease with initial revascularization fails to reduce death or myocardial infarction and inconsistently reduces angina symptoms. Rather, OMT reduces events and improves symptoms and should be considered first-line treatment for patients with CCS.
Transcatheter aortic valve replacement (TAVR) is an effective treatment for severe symptomatic aortic stenosis (AS) in patients who are inoperable or at high risk for surgery. However, the ...intermediate- to long-term mortality is high, emphasizing the importance of patient selection. We, therefore, sought to evaluate the prognostic value of frailty in older recipients of TAVR, hypothesizing that frail patients would experience a higher mortality rate and a higher likelihood of poor outcome 1 year after TAVR. This substudy of the Placement of Aortic Transcatheter Valves trial was conducted at 3 high-enrolling sites where frailty was assessed systematically before TAVR. In total, 244 patients received TAVR at the participating sites. Frailty was assessed using a composite of 4 markers (serum albumin, dominant handgrip strength, gait speed, and Katz activity of daily living survey), which were combined into a frailty score. The cohort was dichotomized at median frailty score. Outcomes measures were the time to death from any cause for >1 year of follow-up and poor outcome at 1 year. Poor outcome was defined as (1) death, (2) Kansas City Cardiomyopathy Questionnaire overall summary (KCCQ-OS) score <60, or (3) decrease of ≥10 points in the KCCQ-OS score from baseline to 1 year. At 1 year, the Kaplan-Meier–estimated all-cause mortality rate was 32.7% in the frail group and 15.9% in the nonfrail group (log-rank p = 0.004). At 1 year, poor outcome occurred in 50.0% of the frail group and 31.5% of the nonfrail group (p = 0.02). In conclusion, frailty was associated with increased mortality and a higher rate of poor outcome 1 year after TAVR.
Intermediate-risk patients with aortic stenosis were randomly assigned to undergo either transcatheter or surgical aortic-valve replacement. At 5 years, there was no significant difference between ...the two groups in the incidence of death or disabling stroke. The incidence of aortic regurgitation was higher with transcatheter AVR.
Molecular dynamics (MD) determines the physical motions of atoms of a biological macromolecule in a cell-like environment and is an important method in structural bioinformatics. Traditionally, ...measurements such as root mean square deviation, root mean square fluctuation, radius of gyration, and various energy measures have been used to analyze MD simulations. Here, we present MD-TASK, a novel software suite that employs graph theory techniques, perturbation response scanning, and dynamic cross-correlation to provide unique ways for analyzing MD trajectories.
MD-TASK has been open-sourced and is available for download from https://github.com/RUBi-ZA/MD-TASK , implemented in Python and supported on Linux/Unix.
o.tastanbishop@ru.ac.za.
IMPORTANCE Significant variations in dose requirements of warfarin and its analogues (acenocoumarol and phenprocoumon) make selecting the appropriate dose for an individual patient difficult. Genetic ...factors account for approximately one-third of the variation in dose requirement. The clinical usefulness of genotype-guided dosing of warfarin has been previously assessed in randomized clinical trials that were limited by lack of power and inconsistent results. OBJECTIVE To compare genotype-guided initial dosing of warfarin and its analogues with clinical dosing protocols. DATA SOURCES AND STUDY SELECTION MEDLINE (inception to December 31, 2013), EMBASE (inception to December 31, 2013), and the Cochrane Library Central Register of Controlled Trials (inception to December 31, 2013) were searched for randomized clinical trials comparing genotype-guided warfarin dosing vs clinical dosing for adults with indications for anticoagulation. DATA EXTRACTION AND SYNTHESIS Two investigators extracted data independently on trial design, baseline characteristics, and outcomes. High-quality studies were considered those that described an appropriate method of randomization, allocation concealment, blinding, and completeness of follow-up. MAIN OUTCOMES AND MEASURES The outcomes analyzed included the percentage of time that the international normalized ratio (INR) was within the therapeutic range, the percentage of patients with an INR greater than 4, and the incidence of major bleeding and thromboembolic events. Summary standardized differences in means (or Mantel-Haenszel risk ratios) were obtained using a random-effects model. RESULTS In 9 trials, 2812 patients were randomized to receive warfarin, acenocoumarol, or phenprocoumon according to a genotype-guided algorithm or a clinical dosing algorithm. Follow-up ranged from 4 weeks to 6 months (median, 12 weeks). The standardized difference in means of the percentage of time that the INR was within the therapeutic range was 0.14 (95% CI, −0.10 to 0.39) in the genotype-guided dosing cohort (P = .25). The risk ratio for an INR greater than 4 was 0.92 (95% CI, 0.82 to 1.05) for genotype-guided dosing vs clinical dosing. The risk ratios for major bleeding and thromboembolic events were 0.60 (95% CI, 0.29 to 1.22) and 0.97 (95% CI, 0.46 to 2.05), respectively, for genotype-guided vs clinical dosing. CONCLUSIONS AND RELEVANCE In this meta-analysis of randomized clinical trials, a genotype-guided dosing strategy did not result in a greater percentage of time that the INR was within the therapeutic range, fewer patients with an INR greater than 4, or a reduction in major bleeding or thromboembolic events compared with clinical dosing algorithms.
•Trump's rural advantage contributed to his Presidential election victory, but it was not sufficient to swing the election.•Trump's average over-performance was higher in more economically-, ...socially-, and health-distressed counties.•Trump performed better in counties with economic distress, poor health, low educational attainment, and high divorce rates.•Localized economic, social, and health distress were salient contributors to the 2016 Presidential election outcome.
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