In comparison to wild-type herpesvirus saimiri, viral interleukin-17 gene knockout mutants have unaltered behavior regarding viral replication, T-cell transformation in vitro, and pathogenicity in cottontop tamarins. Thus, this gene is not required for T-cell lymphoma induction but may contribute to apathogenic viral persistence in the natural host, the squirrel monkey. 相似文献
Several structurally divergent proteins associate with molecular chaperones of the 70-kDa heat shock protein (hsp70) family and modulate their activities. We investigated the cofactors Hap46 and Hop/p60 and the effects of their binding to mammalian hsp70 and the cognate form hsc70. Hap46 associates with the amino-terminal ATP binding domain and stimulates ATP binding two- to threefold but inhibits binding of misfolded protein substrate to hsc70 and reactivation of thermally denatured luciferase in an hsc70-dependent refolding system. By contrast, Hop/p60 interacts with a portion of the carboxy-terminal domain of hsp70s, which is distinct from that involved in the binding of misfolded proteins. Thus, Hop/p60 and substrate proteins can form ternary complexes with hsc70. Hop/p60 exerts no effect on ATP and substrate binding but nevertheless interferes with protein refolding. Even though there is no direct interaction between these accessory proteins, Hap46 inhibits the binding of Hop/p60 to hsc70 but Hop/p60 does not inhibit the binding of Hap46 to hsc70. As judged from respective deletions, the amino-terminal portions of Hap46 and Hop/p60 are involved in this interference. These data suggest steric hindrance between Hap46 and Hop/p60 during interaction with distantly located binding sites on hsp70s. Thus, not only do the major domains of hsp70 chaperones communicate with each other, but cofactors interacting with these domains affect each other as well. 相似文献
The vanilloid-like TRP-channel VRL-1 (TRPV2) is a nonselective cation channel expressed by primary sensory neurons and non-neuronal tissues [Caterina, M.J., Rosen, T.A., Tominaga, M., Brake, A.J and Julius, D. (1999) Nature 398, 436-441]. It is one of the six members of the vanilloid-like TRP-channel family which is now termed the TRPV family [Montell, G., Birnbaumer, L., Flockerzi, V., Bindels, R.J., Brutford, E.A., Caterina, M.J., Clapham, D.E., Harteneck, C., Heller, S., Julius, D., Kojima, I., Mori, Y., Penner, R., Prawitt, D., Scharenberg, A.M., Schultz, G., Shimizu, N. and Zhu, M.X. (2002) Mol. Cell 2, 229-231]. As it is a temperature-gated channel, VRL-1 appears to be functionally related to VR1. In contrast to VR1, VRL-1 is activated at a higher temperature threshold and it does not respond to capsaicin or protons. Here we describe the expression of VRL-1 in the rat dorsal root ganglion-derived cell line F-11, a hybridoma of mouse neuroblastoma (N18TG2) and rat dorsal root ganglion cells. We found by RT-PCR that F-11 cells express not only the rat VRL-1, but also its mouse orthologue in a single cell. The F-11 parental cell line N18TG2 also expressed murine VRL-1. Due to its neuronal character, the DRG-derived F-11 cell line provides an experimental system for the study of VRL-1 biochemistry. However, one has to be aware that both the mouse and the rat protein are expressed simultaneously. Furthermore we cloned VRL-1 from rat brain and analyzed its glycosylation and localization in comparison to the endogenously expressed protein in F-11 cells. In contrast to the endogenous VRL-1 the overexpressed protein is glycosylated. Similar to VR1 the glycosylation is N-linked as shown by an deglycosylation assay. Immunofluorescence analysis of the endogenous VRL-1 in F-11 cells gives only weak signals in the cytoplasm whereas the overexpressed rat VRL-1 appears mainly at the plasma membrane. 相似文献
The impact of trapping on the recombination dynamics in polymer:fullerene blends is clarified using the highly ordered bulk heterojunction (BHJ) blend poly[2,5‐bis(3‐tetradecylthiophen‐2‐yl)thieno[3,2‐b]thiophene] (PBTTT) and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) at different weight ratios as a model system. The recombination dynamics are determined using both transient charge extraction and steady‐state techniques. The results show that both the decay of photogenerated charge and the light ideality factor at a polymer:fullerene weight ratio of 1:4 are fully consistent with 2D Langevin recombination; in the 1:1 case the recombination is seen to be affected by electron trapping. The theory of 2D Langevin recombination is extended to the case with high trap density in agreement with the observations in the 1:1 case. The recombination capture coefficients are derived both for trap‐assisted and band‐to‐band recombination and it can be seen that anisotropic charge transport reduces the capture coefficients in both cases resulting in a reduced overall recombination. 相似文献
Until recently, our understanding of the evolution of human growth and development derived from studies of fossil juveniles that employed extant populations for both age determination and comparison. This circular approach has led to considerable debate about the human-like and ape-like affinities of fossil hominins. Teeth are invaluable for understanding maturation as age at death can be directly assessed from dental microstructure, and dental development has been shown to correlate with life history across primates broadly. We employ non-destructive synchrotron imaging to characterize incremental development, molar emergence, and age at death in more than 20 Australopithecus anamensis, Australopithecus africanus, Paranthropus robustus and South African early Homo juveniles. Long-period line periodicities range from at least 6–12 days (possibly 5–13 days), and do not support the hypothesis that australopiths have lower mean values than extant or fossil Homo. Crown formation times of australopith and early Homo postcanine teeth fall below or at the low end of extant human values; Paranthropus robustus dentitions have the shortest formation times. Pliocene and early Pleistocene hominins show remarkable variation, and previous reports of age at death that employ a narrow range of estimated long-period line periodicities, cuspal enamel thicknesses, or initiation ages are likely to be in error. New chronological ages for SK 62 and StW 151 are several months younger than previous histological estimates, while Sts 24 is more than one year older. Extant human standards overestimate age at death in hominins predating Homo sapiens, and should not be applied to other fossil taxa. We urge caution when inferring life history as aspects of dental development in Pliocene and early Pleistocene fossils are distinct from modern humans and African apes, and recent work has challenged the predictive power of primate-wide associations between hominoid first molar emergence and certain life history variables. 相似文献
Important differences have been demonstrated in laboratory parameters from healthy persons in different geographical regions and populations, mostly driven by a combination of genetic, demographic, nutritional, and environmental factors. Despite this, European and North American derived laboratory reference intervals are used in African countries for patient management, clinical trial eligibility, and toxicity determination; which can result in misclassification of healthy persons as having laboratory abnormalities.
Methods
An observational prospective cohort study known as the Kisumu Incidence Cohort Study (KICoS) was conducted to estimate the incidence of HIV seroconversion and identify determinants of successful recruitment and retention in preparation for an HIV vaccine/prevention trial among young adults and adolescents in western Kenya. Laboratory values generated from the KICoS were compared to published region-specific reference intervals and the 2004 NIH DAIDS toxicity tables used for the trial.
Results
About 1106 participants were screened for the KICoS between January 2007 and June 2010. Nine hundred and fifty-three participants aged 16 to 34 years, HIV-seronegative, clinically healthy, and non-pregnant were selected for this analysis. Median and 95% reference intervals were calculated for hematological and biochemistry parameters. When compared with both published region-specific reference values and the 2004 NIH DAIDS toxicity table, it was shown that the use of locally established reference intervals would have resulted in fewer participants classified as having abnormal hematological or biochemistry values compared to US derived reference intervals from DAIDS (10% classified as abnormal by local parameters vs. >40% by US DAIDS). Blood urea nitrogen was most often out of range if US based intervals were used: <10% abnormal by local intervals compared to >83% by US based reference intervals.
Conclusion
Differences in reference intervals for hematological and biochemical parameters between western and African populations highlight importance of developing local reference intervals for clinical care and trials in Africa. 相似文献
Microbiota provide their hosts with a range of beneficial services, including defense from external pathogens. However, host-associated microbial communities themselves can act as a source of opportunistic pathogens depending on the environment. Marine poikilotherms and their microbiota are strongly influenced by temperature, but experimental studies exploring how temperature affects the interactions between both parties are rare. To assess the effects of temperature, temperature stress and infection on diversity, composition and dynamics of the hemolymph microbiota of Pacific oysters (Crassostrea gigas), we conducted an experiment in a fully-crossed, three-factorial design, in which the temperature acclimated oysters (8 or 22 °C) were exposed to temperature stress and to experimental challenge with a virulent Vibrio sp. strain. We monitored oyster survival and repeatedly collected hemolymph of dead and alive animals to determine the microbiome composition by 16s rRNA gene amplicon pyrosequencing. We found that the microbial dynamics and composition of communities in healthy animals (including infection survivors) were significantly affected by temperature and temperature stress, but not by infection. The response was mediated by changes in the incidence and abundance of operational taxonomic units (OTUs) and accompanied by little change at higher taxonomic levels, indicating dynamic stability of the hemolymph microbiome. Dead and moribund oysters, on the contrary, displayed signs of community structure disruption, characterized by very low diversity and proliferation of few OTUs. We can therefore link short-term responses of host-associated microbial communities to abiotic and biotic factors and assess the potential feedback between microbiota dynamics and host survival during disease. 相似文献
Optoacoustic (photoacoustic) imaging is often performed with one‐dimensional transducer arrays, in analogy to ultrasound imaging. Optoacoustic imaging using linear arrays offers ease of implementation but comes with several performance drawbacks, in particular poor elevation resolution, i.e. the resolution along the axis perpendicular to the focal plane. Herein, we introduce and investigate a bi‐directional scanning approach using linear arrays that can improve the imaging performance to quasi‐isotropic transverse resolution. We study the approach theoretically and perform numerical simulations and phantom measurements to evaluate its performance under defined conditions. Finally, we discuss the features and the limitations of the proposed method.
The poor elevation resolution in a linear scan (left image) is overcome by the proposed bi‐directional scanning approach that yields isotropic transverse resolution (right). 相似文献
AimsResponse to cardiac resynchronization therapy (CRT) is often assessed six months after implantation. Our objective was to assess the number of patients changing from responder to non-responder between six and 14 months, so-called late non-responders, and compare them to patients who were responder both at six and 14 months, so-called stable responders. Furthermore, we assessed predictive values of six and 14-month response concerning clinical outcome.Methods105 patients eligible for CRT were enrolled. Clinical, laboratory, ECG, and echocardiographic parameters and patient-reported health status (Kansas City Cardiomyopathy Questionnaire [KCCQ]) were assessed before, and six and 14 months after implantation. Response was defined as ≥15% LVESV decrease as compared to baseline. Major adverse cardiac events (MACE) were registered until 24 months after implantation. Predictive values of six and 14-month response for MACE were examined.ResultsIn total, 75 (71%) patients were six-month responders of which 12 (16%) patients became late non-responder. At baseline, late non-responders more often had ischemic cardiomyopathy and atrial fibrillation, higher BNP and less dyssynchrony compared to stable responders. At six months, late non-responders showed significantly less LVESV decrease, and higher creatinine levels. Mean KCCQ scores of late non-responders were lower than those of stable responders at every time point, with the difference being significant at 14 months. The 14 months response was a better predictor of MACE than six months response.ConclusionsThe assessment of treatment outcomes after six months of CRT could be premature and response rates beyond might better correlate to long-term clinical outcome. 相似文献