529 research outputs found

    Attention-deficit/hyperactivity disorder medication and seizures

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    OBJECTIVE: Individuals with attention-deficit/hyperactivity disorder (ADHD) are at increased risk of seizures, but there is uncertainty about whether ADHD medication treatment increases risk among patients with and without preexisting seizures. METHODS: We followed a sample of 801,838 patients with ADHD who had prescribed drug claims from the Truven Health MarketScan Commercial Claims and Encounters databases to examine whether ADHD medication increases the likelihood of seizures among ADHD patients with and without a history of seizures. First, we assessed overall risk of seizures among patients with ADHD. Second, within-individual concurrent analyses assessed odds of seizure events during months when a patient with ADHD received ADHD medication compared with when the same individual did not, while adjusting for antiepileptic medications. Third, within-individual long-term analyses examined odds of seizure events in relation to the duration of months over the previous 2 years patients received medication. RESULTS: Patients with ADHD were at higher odds for any seizure compared with non-ADHD controls (odds ratio [OR] = 2.33, 95% confidence interval [CI] = 2.24-2.42 males; OR = 2.31, 95% CI = 2.22-2.42 females). In adjusted within-individual comparisons, ADHD medication was associated with lower odds of seizures among patients with (OR = 0.71, 95% CI = 0.60-0.85) and without (OR = 0.71, 95% CI = 0.62-0.82) prior seizures. Long-term within-individual comparisons suggested no evidence of an association between medication use and seizures among individuals with (OR = 0.87, 95% CI = 0.59-1.30) and without (OR = 1.01, 95% CI = 0.80-1.28) a seizure history. CONCLUSIONS: Results reaffirm that patients with ADHD are at higher risk of seizures. However, ADHD medication was associated with lower risk of seizures within individuals while they were dispensed medication, which is not consistent with the hypothesis that ADHD medication increases risk of seizures

    Two rotary motors in F-ATP synthase are elastically coupled by a flexible rotor and a stiff stator stalk.

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    ATP is synthesized by ATP synthase (F(O)F(1)-ATPase). Its rotary electromotor (F(O)) translocates protons (in some organisms sodium cations) and generates torque to drive the rotary chemical generator (F(1)). Elastic power transmission between F(O) and F(1) is essential for smoothing the cooperation of these stepping motors, thereby increasing their kinetic efficiency. A particularly compliant elastic domain is located on the central rotor (c(10-15)/ε/γ), right between the two sites of torque generation and consumption. The hinge on the active lever on subunit β adds further compliance. It is under contention whether or not the peripheral stalk (and the stator as a whole) also serves as elastic buffer. In the enzyme from Escherichia coli, the most extended component of the stalk is the homodimer b(2), a right-handed α-helical coiled coil. By fluctuation analysis we determined the spring constant of the stator in response to twisting and bending, and compared wild-type with b-mutant enzymes. In both deformation modes, the stator was very stiff in the wild type. It was more compliant if b was elongated by 11 amino acid residues. Substitution of three consecutive residues in b by glycine, expected to destabilize its α-helical structure, further reduced the stiffness against bending deformation. In any case, the stator was at least 10-fold stiffer than the rotor, and the enzyme retained its proton-coupled activity

    Myo4p is a monomeric myosin with motility uniquely adapted to transport mRNA

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    The yeast Saccharomyces cerevisiae uses two class V myosins to transport cellular material into the bud: Myo2p moves secretory vesicles and organelles, whereas Myo4p transports mRNA. To understand how Myo2p and Myo4p are adapted to transport physically distinct cargos, we characterize Myo2p and Myo4p in yeast extracts, purify active Myo2p and Myo4p from yeast lysates, and analyze their motility. We find several striking differences between Myo2p and Myo4p. First, Myo2p forms a dimer, whereas Myo4p is a monomer. Second, Myo4p generates higher actin filament velocity at lower motor density. Third, single molecules of Myo2p are weakly processive, whereas individual Myo4p motors are nonprocessive. Finally, Myo4p self-assembles into multi-motor complexes capable of processive motility. We show that the unique motility of Myo4p is not due to its motor domain and that the motor domain of Myo2p can transport ASH1 mRNA in vivo. Our results suggest that the oligomeric state of Myo4p is important for its motility and ability to transport mRNA

    An analysis of identical single-nucleotide polymorphisms genotyped by two different platforms

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    The overlap of 94 single-nucleotide polymorphisms (SNP) among the 4,720 and 11,120 SNPs contained in the linkage panels of Illumina and Affymetrix, respectively, allows an assessment of the discrepancy rate produced by these two platforms. Although the no-call rate for the Affymetrix platform is approximately 8.6 times greater than for the Illumina platform, when both platforms make a genotypic call, the agreement is an impressive 99.85%. To determine if disputed genotypes can be resolved without sequencing, we studied recombination in the region of the discrepancy for the most discrepant SNP rs958883 (typed by Illumina) and tsc02060848 (typed by Affymetrix). We find that the number of inferred recombinants is substantially higher for the Affymetrix genotypes compared to the Illumina genotypes. We illustrate this with pedigree 10043, in which 3 of 7 versus 0 of 7 offspring must be double recombinants using the genotypes from the Affymetrix and the Illumina platforms, respectively. Of the 36 SNPs with one or more discrepancies, we identified a subset that appears to cluster in families. Some of this clustering may be due to the presence of a second segregating SNP that obliterates a XbaI site (the restriction enzyme used in the Affymetrix platform), resulting in a fragment too long (>1,000 bp) to be amplified

    Updates in the management of brain metastases

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    The clinical management/understanding of brain metastases (BM) has changed substantially in the last 5 years, with key advances and clinical trials highlighted in this review. Several of these changes stem from improvements in systemic therapy, which have led to better systemic control and longer overall patient survival, associated with increased time at risk for developing BM. Development of systemic therapies capable of preventing BM and controlling both intracranial and extracranial disease once BM are diagnosed is paramount. The increase in use of stereotactic radiosurgery alone for many patients with multiple BM is an outgrowth of the desire to employ treatments focused on local control while minimizing cognitive effects associated with whole brain radiotherapy. Complications from BM and their treatment must be considered in comprehensive patient management, especially with greater awareness that the majority of patients do not die from their BM. Being aware of significant heterogeneity in prognosis and therapeutic options for patients with BM is crucial for appropriate management, with greater attention to developing individual patient treatment plans based on predicted outcomes; in this context, recent prognostic models of survival have been extensively revised to incorporate molecular markers unique to different primary cancers

    Liquid-Crystal-Based Controllable Attenuators Operating in the 1-4 Terahertz Band

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    Liquid-crystal devices (LCDs) offer a potential route toward adaptive optical components for use in the < 2 THz band of the electromagnetic spectrum. We demonstrate LCDs using a commercially available material (E7), with unbiased birefringence values of 0.14-0.18 in the 0.3-4 THz band. We exploit the linear dichroism of the material to modulate the emission from a 3.4-THz quantum cascade laser by up to 40%, dependent upon both the liquid-crystal layer thickness and the bias voltage applied.Comment: 10 pages, 6 figure

    Phylogenomics reveals the history of host use in mosquitoes

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    Mosquitoes have profoundly affected human history and continue to threaten human health through the transmission of a diverse array of pathogens. The phylogeny of mosquitoes has remained poorly characterized due to difficulty in taxonomic sampling and limited availability of genomic data beyond the most important vector species. Here, we used phylogenomic analysis of 709 single copy ortholog groups from 256 mosquito species to produce a strongly supported phylogeny that resolves the position of the major disease vector species and the major mosquito lineages. Our analyses support an origin of mosquitoes in the early Triassic (217 MYA [highest posterior density region: 188–250 MYA]), considerably older than previous estimates. Moreover, we utilize an extensive database of host associations for mosquitoes to show that mosquitoes have shifted to feeding upon the blood of mammals numerous times, and that mosquito diversification and host-use patterns within major lineages appear to coincide in earth history both with major continental drift events and with the diversification of vertebrate classes. © 2023, Springer Nature Limited
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