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61.
Kozlov AS Andor-Ardó D Hudspeth AJ 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(8):2896-2901
The ear detects sounds so faint that they produce only atomic-scale displacements in the mechanoelectrical transducer, yet thermal noise causes fluctuations larger by an order of magnitude. Explaining how hearing can operate when the magnitude of the noise greatly exceeds that of the signal requires an understanding both of the transducer's micromechanics and of the associated noise. Using microrheology, we characterize the statistics of this noise; exploiting the fluctuation-dissipation theorem, we determine the associated micromechanics. The statistics reveal unusual Brownian motion in which the mean square displacement increases as a fractional power of time, indicating that the mechanisms governing energy dissipation are related to those of energy storage. This anomalous scaling contradicts the canonical model of mechanoelectrical transduction, but the results can be explained if the micromechanics incorporates viscoelasticity, a salient characteristic of biopolymers. We amend the canonical model and demonstrate several consequences of viscoelasticity for sensory coding. 相似文献
62.
N Biris Y Yang AB Taylor A Tomashevski M Guo PJ Hart F Diaz-Griffero DN Ivanov 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(33):13278-13283
Tripartite motif protein TRIM5α blocks retroviral replication after cell entry, and species-specific differences in its activity are determined by sequence variations within the C-terminal B30.2/PRYSPRY domain. Here we report a high-resolution structure of a TRIM5α PRYSPRY domain, the PRYSPRY of the rhesus monkey TRIM5α that potently restricts HIV infection, and identify features involved in its interaction with the HIV capsid. The extensive capsid-binding interface maps on the structurally divergent face of the protein formed by hypervariable loop segments, confirming that TRIM5α evolution is largely determined by its binding specificity. Interactions with the capsid are mediated by flexible variable loops via a mechanism that parallels antigen recognition by IgM antibodies, a similarity that may help explain some of the unusual functional properties of TRIM5α. Distinctive features of this pathogen-recognition interface, such as structural plasticity conferred by the mobile v1 segment and interaction with multiple epitopes, may allow restriction of divergent retroviruses and increase resistance to capsid mutations. 相似文献
63.
Ho JE Waters DD Kean A Wilson DJ Demicco DA Breazna A Wun CC Deedwania PC Khush KK;TNT Investigators 《The American journal of cardiology》2012,109(12):1761-1766
Impaired kidney function often accompanies heart failure (HF) and is associated with a worse prognosis. This post hoc analysis of the Treating to New Targets (TNT) trial examined whether the observed decrease in HF hospitalizations with high- compared to low-dose atorvastatin could be related to improvements in kidney function. Of 10,001 TNT participants, 9,376 had estimated glomerular filtration rate (eGFR) measurements at baseline and 1 year and were included in this analysis. The association of change in year-1 eGFR and subsequent HF hospitalization was examined using Cox regression models. In total 218 participants developed subsequent HF hospitalization. Little change in eGFR occurred over 1 year in the atorvastatin 10-mg group, whereas eGFR improved in the 80-mg group by 1.48 ml/min/1.73 m(2) (95% confidence interval 1.29 to 1.67, p <0.0001). Subsequent HF was preceded by a decrease in eGFR over 1 year compared to modest improvement in those without subsequent HF (-0.09 ± 7.89 vs 0.81 ± 6.90 ml/min/1.73 m(2), p = 0.0015). After adjusting for baseline eGFR, each 5-ml/min/1.73 m(2) increase in eGFR at 1 year was associated with a lower risk of subsequent HF hospitalization (hazard ratio 0.85, 95% confidence interval 0.77 to 0.94, p = 0.002). This relation was independent of treatment effect or change in low-density lipoprotein cholesterol level at 1 year. In conclusion, treatment with high- compared to low-dose atorvastatin was associated with improvement in eGFR at 1 year, which was related to a decrease in subsequent HF hospitalization. This suggests that improvement in kidney function may be related to the beneficial effect of high-dose atorvastatin on HF hospitalization. 相似文献
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Allan Watkinson Andrei Soliakov Ashok Ganesan Karie Hirst Chris LeButt Kelly Fleetwood Peter C. Fusco Thomas R. Fuerst Jeremy H. Lakey 《Clinical and Vaccine Immunology : CVI》2013,20(11):1659-1668
Aluminum salts are the most widely used vaccine adjuvants, and phosphate is known to modulate antigen-adjuvant interactions. Here we report an unexpected role for phosphate buffer in an anthrax vaccine (SparVax) containing recombinant protective antigen (rPA) and aluminum oxyhydroxide (AlOH) adjuvant (Alhydrogel). Phosphate ions bind to AlOH to produce an aluminum phosphate surface with a reduced rPA adsorption coefficient and binding capacity. However, these effects continued to increase as the free phosphate concentration increased, and the binding of rPA changed from endothermic to exothermic. Crucially, phosphate restored the thermostability of bound rPA so that it resembled the soluble form, even though it remained tightly bound to the surface. Batches of vaccine with either 0.25 mM (subsaturated) or 4 mM (saturated) phosphate were tested in a disease model at batch release, which showed that the latter was significantly more potent. Both formulations retained their potency for 3 years. The strongest aluminum adjuvant effects are thus likely to be via weakly attached or easily released native-state antigen proteins. 相似文献
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68.
Mircean V Dumitrache MO Györke A Pantchev N Jodies R Mihalca AD Cozma V 《Vector borne and zoonotic diseases (Larchmont, N.Y.)》2012,12(7):595-604
Tick-borne diseases are of great concern worldwide. Despite this, in Romania there is only limited information regarding the prevalence of vector-borne pathogens in dogs. In all, 1146 serum samples were tested by SNAP(?) 4Dx(?) (IDEXX Laboratories, Inc., Westbrook, ME) for Anaplasma phagocytophilum, Borrelia burgdorferi, and Ehrlichia canis antibodies, and for Dirofilaria immitis antigen. The correlation between positive cases and their geographic distribution, as well as potential risk factors (age, sex, breed, type of dog, habitat, and prophylactic treatments) were evaluated. Overall, 129 dogs (11.3%) were serologically-positive to one or more of the tested pathogens. The seroprevalence for the four infectious agents were: A. phagocytophilum 5.5% (63/1146), D. immitis 3.3% (38/1146), E. canis 2.1% (24/1146), and B. burgdorferi 0.5% (6/1146). Co-infection with E. canis and A. phagocytophilum was registered in 2 dogs (0.2%). The geographical distribution of the seropositive cases suggests clustered foci in southern regions and in the western part of the country for D. immitis, and in the southeastern region (Constan?a County) for E. canis. A. phagocytophilum and B. burgdorferi showed a homogenous distribution, with a tendency for Lyme-positive samples to concentrate in central Romania. For D. immitis, A. phagocytophilum, and E. canis, administering prophylactic treatments was a risk factor associated with infection. Another associated risk factor was the type of dog (stray dogs were at risk being positive for D. immitis, shelter dogs for E. canis, and hunting dogs for B. burgdorferi). The prevalence of D. immitis was significantly higher in males and in dogs older than 2 years. This survey represents the first data detailing A. phagocytophilum and E. canis seroprevalence in Romanian dogs, and the most comprehensive epidemiological study on vector-borne infections in dogs from this country. 相似文献
69.
Andrei D Taut Qiming Jin Jong‐Hyuk Chung Pablo Galindo‐Moreno Erica S Yi James V Sugai Hua Z Ke Min Liu William V Giannobile 《Journal of bone and mineral research》2013,28(11):2347-2356
The reconstruction of large osseous defects due to periodontitis is a challenge in regenerative therapy. Sclerostin, secreted by osteocytes, is a key physiological inhibitor of osteogenesis. Pharmacologic inhibition of sclerostin using sclerostin‐neutralizing monoclonal antibody (Scl‐Ab) thus increases bone formation, bone mass and bone strength in models of osteopenia and fracture repair. This study assessed the therapeutic potential of Scl‐Ab to stimulate alveolar bone regeneration following experimental periodontitis (EP). Ligature‐induced EP was induced in rats to generate localized alveolar bone defects. Following 4 weeks of disease induction, Scl‐Ab (+EP) or vehicle (+/? EP) were systemically delivered, twice weekly for up to 6 wks to determine the ability of Scl‐Ab to regenerate bone around tooth‐supporting osseous defects. 3 and 6 wks after the initiation of Scl‐Ab or vehicle treatment, femur and maxillary jawbones were harvested for histology, histomorphometry, and micro‐computed tomography (micro‐CT) of linear alveolar bone loss (ABL) and volumetric measures of bone support, including bone volume fraction (BVF) and tissue mineral density (TMD). Serum was analyzed to examine bone turnover markers during disease and regenerative therapy. Vehicle + EP animals exhibited maxillary bone loss (BVF, TMD and ABL) at ligature removal and thereafter. 6 weeks of Scl‐Ab significantly improved maxillary bone healing, as measured by BVF, TMD and ABL, when compared to vehicle + EP. After 6 weeks of treatment, BVF and TMD values in the Scl‐Ab + EP group were similar to those of healthy controls. Serum analysis demonstrated higher levels of bone formation markers osteocalcin and PINP in Scl‐Ab treatment groups. Scl‐Ab restored alveolar bone mass following experimental periodontitis. These findings warrant further exploration of Scl‐Ab therapy in this and other oral bone defect disease scenarios. © 2013 American Society for Bone and Mineral Research. 相似文献
70.
Sayak Ghatak Marie Reveiller Liana Toia Andrei Ivanov Tony E. Godfrey Jeffrey H. Peters 《Journal of gastrointestinal surgery》2013,17(10):1723-1731