Citations

We tested the hypothesis that reduced nitric oxide (NO) bioavailability contributes to the attenuated peak and total vasodilation following single-muscle contractions in older adults. Young ( n = 10; 24 ± 2 yr) and older ( n = 10; 67 ± 2 yr) adults performed single forearm contractions at 10, 20, and 40% of maximum during saline infusion (control) and NO synthase (NOS) inhibition via NG-monomethyl-l-arginine. Brachial artery diameters and velocities were measured using Doppler ultrasound and forearm vascular conductance (FVC; in ml·min−1·100 mmHg−1) was calculated from blood flow (ml/min) and blood pressure (mmHg). Peak and total vasodilator responses [change (Δ) in FVC from baseline] were attenuated in older adults at all intensities ( P < 0.05). NOS inhibition reduced the peak ΔFVC at 10% (88 ± 12 vs. 52 ± 9 ml·min−1·100 mmHg−1), 20% (125 ± 13 vs. 83 ± 13 ml·min−1·100 mmHg−1), and 40% (207 ± 26 vs. 133 ± 20 ml·min−1·100 mmHg−1) in young subjects, ( P < 0.05 for all) and in older adults at 10% (59 ± 5 vs. 47 ± 7 ml·min−1·100 mmHg−1, P < 0.05) and 20% (88 ± 9 vs. 68 ± 9 ml·min−1·100 mmHg−1, P < 0.05), but not 40% (128 ± 12 vs. 105 ± 11 ml·min−1·100 mmHg−1, P = 0.11). The relative (%) reduction in peak ΔFVC due to NOS inhibition was greater in young vs. older adults at 20% (−36 ± 5 vs. −23 ± 5%, P < 0.05) and 40% (−35 ± 6 vs. −16 ± 7%, P < 0.05). The reduction in the total vasodilator response (area under the curve) with NOS inhibition was also greater in young vs. older adults at all intensities. Our data suggest that contraction-induced rapid vasodilation is mediated in part by NO, and that the contribution of NO is greater in young adults.

AbstractBackgroundThe term pharmacogenetics is used to describe an evolving field that aims to understand the relationship between individual variations in genetic sequence and differences in the therapeutic and toxic response to medications. The promise of pharmacogenetics is empowerment of clinicians with information that will enable them to personalize drug therapy – to prescribe the right medication at the right dose for each patient, while minimizing adverse effects. Despite dramatic advances, wide application of pharmacogenetics to clinical practice has been slow for a number of reasons, including lack of evidence‐based therapeutic guidelines as well as ethical concerns and cost.MethodsTo illustrate applications to dermatology practice, we present three clinical scenarios that serve as a springboard for discussion of the principles of pharmacogenetics and how they can be used to guide treatment with azathioprine, 5‐fluorouracil, and trastuzumab.ConclusionThe therapeutic and toxic effects of a given medication ultimately depend on its combined pharmacokinetic, pharmacodynamic, and pharmacogenetic properties in a given individual. Pharmacodynamic properties of individual medications must be correlated with single nucleotide polymorphisms. Test recommendations and standardization of therapy for specific disorders can then be established.

Disease OverviewWaldenström macroglobulinemia (WM) is a lymphoplasmacytic lymphoma with immunoglobulin M (IgM) monoclonal protein. Clinical features include anemia, thrombocytopenia, hepatosplenomegaly, and lymphadenopathy.DiagnosisThe presence of IgM monoclonal protein associated with ≥10% clonal lymphoplasmacytic cells in bone marrow confirms the diagnosis.Risk StratificationAge, hemoglobin level, platelet count, β2 microglobulin, and monoclonal IgM concentrations are characteristics required for prognosis.Risk‐Adapted TherapyNot all patients who fulfill WM criteria require therapy; these patients can be observed until symptoms develop. Rituximab‐based therapy is used in virtually all US patients with WM and can be combined with alkylating agent or purine nucleoside analog (or both). The preferred Mayo Clinic nonstudy therapeutic induction is rituximab, cyclophosphamide, and dexamethasone. Future stem cell transplantation should be considered in induction therapy selection.Management of Refractory DiseaseBortezomib, thalidomide, everolimus, lenalidomide, and bendamustine have all been shown to have activity in WM. Given WM's natural history, reduction of complications will be a priority for future treatment trials. Am. J. Hematol. 88:703–711, 2013. © 2013 Wiley Periodicals, Inc.

AbstractObjectiveThe Suspicion Index (SI) screening tool was developed to identify patients suspected of having Niemann‐Pick disease type C (NP‐C). The SI provides a risk prediction score (RPS) based on NP‐C manifestations within and across domains (visceral, neurological, and psychiatric). The aim of these subanalyses was to further examine the discriminatory power of the SI by age and manifestation–associations by NP‐C suspicion‐level and leading manifestations.MethodsThe original retrospectively collected data were split into three patient age groups, where NP‐C‐positive cases were >16 years (n = 30), 4–16 years (n = 18), and <4 years (n = 23), and patients’ RPS were analyzed by logistic regression. Co‐occurrence of manifestations within groups of suspicion level (low, medium, high) and leading manifestations (presence/absence of ataxia, cognitive decline, psychosis, and splenomegaly) were analyzed descriptively.ResultsNP‐C‐positive cases versus controls showed strong discriminatory power of RPS. Area under the receiver operating characteristic curve was 0.964 (>16 years) and 0.981 (4–16 years) but weaker 0.562 for infants (<4 years). Patients with RPS <70 were characterized by a lack of psychiatric manifestations and low levels of neurological involvement, suggestive of a preneurological phase of the disease. In patients >4 years, prominent leading manifestation–associations were ataxia with dystonia, dysarthria/dysphagia, and cognitive decline. Psychosis was associated with dysarthria/dysphagia but also with cognitive decline and treatment‐resistant psychiatric symptoms.ConclusionsThe SI tool maintains strong discriminatory power in patients >4 years but is not as useful for infants <4 years. The SI is also informative regarding the association and co‐occurrence of manifestations in patients with NP‐C.

Purpose In this study, the authors examined how signal clarity interacts with the use of sentence context information in determining speech-in-noise recognition for children with cochlear implants and children with normal hearing. Method One hundred and twenty sentences in which the final word varied in predictability (high vs. low semantic context) were produced in conversational and clear speech. Nine children with cochlear implants and 9 children with normal hearing completed the sentence-in-noise listening tests and a standardized language measure. Results Word recognition in noise improved significantly for both groups of children for high-predictability sentences in clear speech. Children with normal hearing benefited more from each source of information compared with children with cochlear implants. There was a significant correlation between more developed language skills and the ability to use contextual enhancements. The smaller context gain in clear speech for children with cochlear implants is in accord with the effortfulness hypothesis (McCoy et al., 2005) and points to the cumulative effects of noise throughout the processing system. Conclusion Modifications of the speech signal and the context of the utterances through changes in the talker output hold substantial promise as a communication enhancement technique for both children with cochlear implants and children with normal hearing.