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991.
OBJECTIVES: This study examined how patient acceptability influences the effectiveness of directly observed therapy for tuberculosis. METHODS: Decision and sensitivity analyses were used in assessing influences. RESULTS: If mandatory directly observed therapy discourages 6% of initial tuberculosis patients (range: 4% to 10%) from seeking care, then such therapy will be less effective than self-administered therapy. Directly observed therapy is more effective than repeated self-administered therapy for patients failing to complete initial treatment unless 32% (range: 27% to 38%) of patients avoid seeking care. CONCLUSIONS: Patient acceptability must be taken into consideration before selecting public health strategies.  相似文献   
992.
The dihydrolipoyl acetyltransferase (E2 component) is a 60-mer assembled via its COOH-terminal domain with exterior E1-binding domain and two lipoyl domains (L2 then L1) sequentially connected by mobile linker regions. E2 facilitates markedly enhanced function of the pyruvate dehydrogenase kinase (PDK) and pyruvate dehydrogenase phosphatase (PDP). Human E2 structures were prepared with only one lipoyl domain (L1 or L2) or with alanines substituted at the sites of lipoylation (Lys-46 in L1 or Lys-173 in L2). The L2 domain and its lipoyl group were shown to be essential for markedly enhanced PDP function and were required for greatly up-regulated PDK function. The complete absence of the L1 domain reduced the enhancements of both of these activities but not the maximal effector-stimulated PDK activity through acetylation of L2. With nonlipoylated L2 present, lipoylated L1 supported a lesser enhancement in PDK function with significant stimulation upon acetylation of L1. Prevention of L1 lipoylation in K46AE2 removed this competitive L1 role and enhanced L2-facilitated PDK activity beyond that of native E2 when PDK activity was measured in the absence or in the presence of stimulatory effectors. Thus, the E2-L2 domain has a paramount role in facilitating enhanced PDK and PDP function but inclusion of E2-L1 domain, even in a noninteracting (nonlipoylated) form, contributes to the marked elevation of these activities.  相似文献   
993.
MOTIVATION: Peptide and protein structures are determined daily using NMR spectroscopy. Assignment of the NMR spectra is an important step within the procedure and is usually the limiting one. Computer-aided assignment tools should be user friendly with open architecture to communicate with other programs involved in the structure determination. RESULTS: Here we present an interactive NMR assignment module which provides numerous graphic tools for the user. The module is composed of a database management system-handling peaks, spins and spin-systems. The assignment information is maintained as a set of interrelated associative arrays, which serve as generic high-level data structures. The module is developed in the macro language embedded in the Gifa NMR processing program (Pons et al. , J. Biomol. NMR, 8 , 445-452, 1996). This provides the user with a consistent interface, a set of sophisticated tools, and an easily extendible and customizable environment. AVAILABILITY: The program is available on request from the authors. The Gifa package can be accessed at: ((http://www.cbs. univ-montp1.fr/GIFA)) CONTACT: Marc-Andre.Delsuc@cbs.univ-montp1.fr  相似文献   
994.
Gold nanorods have the potential to be employed as extremely bright molecular marker labels for fluorescence, absorption, or scattering imaging of living tissue. However, samples containing a large number of gold nanorods usually exhibit relatively wide spectral lines. This linewidth limits the use of the nanorods as effective molecular labels, since it would be rather difficult to image several types of nanorod markers simultaneously. In addition, the observed linewidth does not agree well with theoretical calculations, which predict significantly narrower absorption and scattering lines. The discrepancy could be explained by apparent broadening because of the contribution of nanorods with various sizes and aspect ratios. We measured native scattering spectra of single gold nanorods with the confocal light absorption and scattering spectroscopy system, and found that single gold nanorods have a narrow spectrum as predicted by the theory, which suggests that nanorod-based molecular markers with controlled narrow aspect ratios, and to a lesser degree size distributions, should provide spectral lines sufficiently narrow for effective biomedical imaging.  相似文献   
995.
The study investigated differences in behavior synchrony of dairy cows during the winter confinement period when managed in 1 of 3 out-wintering pad (OWP) systems, or indoors in free-stall housing. There were 2 replicates of each treatment, and observations were carried out on 3 recording occasions in January and February 2006. On each recording occasion, behavior was recorded every 30 min between 0600 and 0130 h the following day (n = 40). The outcomes for measurement were eligible cows lying (ECL), cow comfort index (CCI), and proportion of animals feeding (AF). Autocorrelation as an indicator of synchrony was calculated using the Durban-Watson statistic and compared across treatments. A centered moving average was calculated, used to obtain the residual, and compared between treatments. Low autocorrelations were recorded in free stalls (39.6 ± 0.1%), indicating lower temporal behavioral synchrony than in the 3 OWP designs. Overall, the greatest proportion of ECL, CCI, and AF occurred in free stalls (60%). However, high proportions (>90%) of ECL were recorded on OWP in the early morning, whereas the range of ECL in free stalls (22 to 87%) was lower. The low overall proportions for ECL (44, 52, and 54%) and CCI (48, 55, and 58%) in the OWP were caused by the cows standing without feeding during daylight hours. Nevertheless, these cows performed more synchronized lying at night, and their behavior was more highly autocorrelated (65.9 ± 0.1, 73.3 ± 0.1, and 52.3 ± 0.1%) than cows in free stalls. Synchrony of behavior is part of the normal behavior repertoire of herd-living animals such as dairy cattle, and OWP may promote a more natural circadian behavior pattern than do free-stall systems. It is important that indices such as CCI and ECL are utilized at appropriate times of the day, when cows are expected to lie; that is, during the evening time. Estimated acceptable levels of these indices may be dependent on the confinement system employed.  相似文献   
996.
Mechanisms responsible for neuroattenuation of herpes simplex virus (HSV) have been defined previously by studies of mutant viruses in cultured cells. The hypothesis that null mutations in host genes can override the attenuated phenotype of null mutations in certain viral genes was tested. Mutants such as those in infected cell protein (ICP) 0, thymidine kinase, ribonucleotide reductase, virion host shutoff, and ICP34.5 are reduced in their capacity to replicate in nondividing cells in culture and in vivo. The replication of these viruses was examined in eyes and trigeminal ganglia for 1-7 d after corneal inoculation in mice with null mutations (-/-) in interferon receptors (IFNR) for type I IFNs (IFN-alpha/betaR), type II IFN (IFN-gammaR), and both type I and type II IFNs (IFN-alpha/beta/gammaR). Viral titers in eyes and ganglia of IFN-gammaR-/- mice were not significantly different from congenic controls. However, in IFN-alpha/betaR-/- or IFN-alpha/beta/gammaR-/- mice, growth of all mutants, including those with significantly impaired growth in cell culture, was enhanced by up to 1,000-fold in eyes and trigeminal ganglia. Blepharitis and clinical signs of infection were evident in IFN-alpha/betaR-/- and IFN-alpha/beta/gammaR-/- but not control mice for all viruses. Also, IFNs were shown to significantly reduce productive infection of, and spread from intact, but not scarified, corneas. Particularly striking was restoration of near-normal trigeminal ganglion replication and neurovirulence of an ICP34.5 mutant in IFN-alpha/betaR-/- mice. These data show that IFNs play a major role in limiting mutant and wild-type HSV replication in the cornea and in the nervous system. In addition, the in vivo target of ICP34.5 may be host IFN responses. These experiments demonstrate an unsuspected role for host factors in defining the phenotypes of some HSV mutants in vivo. The phenotypes of mutant viruses therefore cannot be interpreted based solely upon studies in cell culture but must be considered carefully in the context of host factors that may define the in vivo phenotype.  相似文献   
997.
The anaphylatoxin C3a has been reported to have immunomodulatory effects on a number of different cell types. In this study we investigated the effects of C3a and C3a(desArg) on gene expression and protein secretion of IL-6 in human PBMCs, either alone or in combination with LPS or IL-1beta. C3a or C3a(desArg) alone exhibited no effect on the expression or secretion of IL-6. However, when PBMC were stimulated with LPS or IL-1beta, both C3a and C3a(desArg) were found to enhance IL-6 release by PBMC in a dose-dependent manner. Since C3a has been shown to induce PGE2 production by monocytes, and PGE2 has been shown to influence cytokine production, we investigated the potential role of PGE2 in C3a-mediated enhancement of LPS- and IL-1beta-induced IL-6 production. Indomethacin blocked PGE2 release, but had no influence on the observed effects of C3a, suggesting that the effects of C3a on IL-6 production are independent of PGE2 formation by monocytes. Northern blot analysis showed that C3a as well as C3a(desArg) enhanced LPS-induced mRNA levels for IL-6. Pretreatment of PBMCs with pertussis toxin blocked the functions of C3a and C3a(desArg), indicating that the actions of these two molecules are mediated by a G protein-coupled pathway. Furthermore, we investigated the effects of C3a and C3a(desArg) on induction of NF-kappaB and activating protein-1 binding. Both molecules enhanced LPS-induced NF-kappaB and activating protein-1 binding activity. These results demonstrate the capacity of intact C3a and its circulating des-Arg form to exert immunmodulatory effects in vitro.  相似文献   
998.
High precision quantitative angiography   总被引:1,自引:0,他引:1  
Statistical considerations on the precision in the determination of blood vessel dimensions from digitized cine angiographic images are described. The resolution requirements related to "point measurements" and segmental diameter curve evaluations are discussed. The error associated with inaccurate determination of the vessel's centerline is analyzed. The concepts have been implemented on a high-speed image analyzing system, which measures blood vessel diameters with advanced automation. The performance of the system was evaluated with blood vessel phantoms, ranging in diameter from 0.88 to 6.26 mm. For these phantoms the minimum measurable change in vessel dimension over 20-pixel (-1.1 mm) long segments ranged from 3.4 to 0.2 percent, respectively.  相似文献   
999.
The dihydrolipoyl acetyltransferase (E2) component of mammalian pyruvate dehydrogenase complex (PDC) consists of 60 COOH-terminal domains as an inner assemblage and sequentially via linker regions an exterior pyruvate dehydrogenase (E1) binding domain and two lipoyl domains. Mature human E2, expressed in a protease-deficient Escherichia coli strain at 27 degrees , was prepared in a highly purified form. Purified E2 had a high acetyltransferase activity, was well lipoylated based on its acetylation, and bound a large complement of bovine E1. Electron micrographs demonstrated that the inner core was assembled in the expected pentagonal dodecahedron shape with E1 binding around the inner core periphery. With saturating E1 and excess dihydrolipoyl dehydrogenase (E3) but no E3-binding protein (E3BP), the recombinant E2 supported the overall PDC reaction at 4% of the rate of bovine E2.E3BP subcomplex. The lipoates of assembled human E2 or its free bilipoyl domain region were reduced by E3 at rates proportional to the lipoyl domain concentration, but those of the E2.E3BP were rapidly used in a concentration-independent manner consistent with bound E3 rapidly using a set of lipoyl domains localized nearby. Given this restriction and the need for E3BP for high PDC activity, directed channeling of reducing equivalents to bound E3 must be very efficient in the complex. The recombinant E2 oligomer increased E1 kinase activity by up to 4-fold and, in a Ca2+-dependent process, increased phospho-E1 phosphatase activity more than 15-fold. Thus the E2 assemblage fully provides the molecular intervention whereby a single E2-bound kinase or phosphatase molecule rapidly phosphorylate or dephosphorylate, respectively, many E2-bound E1. Thus, we prepared properly assembled, fully functional human E2 that mediated enhanced regulatory enzyme activities but, lacking E3BP, supported low PDC activity.  相似文献   
1000.
We reported our findings on the development and preliminary validation of a Spanish-language measure of positive and negative affect. Using confirmatory factor analytic techniques on data generated by 708 women in northern Spain, we obtained reasonable construct validity and reliability data for the measure. Consistent with past cross-cultural studies, a two-factor Positive Affect-Negative Affect (PA-NA)structure emerged, with PA and NA as relatively independent entities. The structure in this sample converged with that reported for a culturally separate group of participants. This factor structure has therefore revealed invariance across a number of cultural groups in Asia, Europe, and North America.  相似文献   
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