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891.
We previously reported that a 3-pyridinecarbonitrile analog with a furan substituent at C-5 and a 4-methylindol-5-ylamino substituent at C-4, 1, was a potent inhibitor of PKCθ (IC50 = 4.5 nM). Replacement of the C-5 furan ring of 1 with bicyclic heteroaryl rings, led to compounds with significantly improved potency against PKCθ. Analog 6b with a 4-methylindol-5-ylamino group at C-4 and a 5-[(4-methylpiperazin-1-yl)methyl]-1-benzofuran-2-yl group at C-5 had an IC50 value of 0.28 nM for the inhibition of PKCθ.  相似文献   
892.
Animal communication involves the transfer of information between a sender and one or more receivers. However, such interactions do not happen in a social vacuum; third parties are typically present, who can potentially eavesdrop upon or intervene in the interaction. The importance of such bystanders in shaping the outcome of communicative interactions has been widely studied in humans, but has only recently received attention in other animal species. Here, we studied bouts of infant crying among rhesus macaques (Macaca mulatta) in order to investigate how the presence of bystanders may affect the outcome of this signalling interaction between infants and mothers. It was hypothesized that, as crying is acoustically aversive, bystanders may be aggressive to the mother or the infant in order to bring the crying bout to a close. Consequently, it was predicted that mothers should acquiesce more often to crying if in the presence of potentially aggressive animals. In line with this prediction, it was found that mothers gave infants access to the nipple significantly more often when crying occurred in the presence of animals that posed a high risk of aggression towards them. Both mothers and infants tended to receive more aggression from bystanders during crying bouts than outside of this time, although such aggression was extremely rare and was received by less than half of the mothers and infants in the study. Mothers were also found to be significantly more aggressive to their infants while the latter were crying than outside of crying bouts. These results provide new insight into the complex dynamics of mother–offspring conflict, and indicate that bystanders may play an important role in shaping the outcome of signalling interactions between infants and their mothers.  相似文献   
893.
This paper aims to instruct the reader in the assembly and operation of an infrared near-field microscope for imaging beyond the diffraction limit. The apertureless near-field microscope is a light scattering-type instrument that provides infrared spectra at circa 20 nm resolution. A complete list of components and a step-by-step protocol for use is provided. Common errors in assembly and instrument tuning are discussed. A representative data set that shows the secondary structure of an amyloid fibril is presented.  相似文献   
894.
Simian immunodeficiency virus (SIV)-infected African nonhuman primates do not progress to AIDS in spite of high and persistent viral loads (VLs). Some authors consider the high viral replication observed in chronic natural SIV infections to be due to lower anti-SIV antibody titers than those in rhesus macaques, suggesting a role of antibodies in controlling viral replication. We therefore investigated the impact of antibody responses on the outcome of acute and chronic SIVagm replication in African green monkeys (AGMs). Nine AGMs were infected with SIVagm.sab. Four AGMs were infused with 50 mg/kg of body weight anti-CD20 (rituximab; a gift from Genentech) every 21 days, starting from day −7 postinfection up to 184 days. The remaining AGMs were used as controls and received SIVagm only. Rituximab-treated AGMs were successfully depleted of CD20 cells in peripheral blood, lymph nodes (LNs), and intestine, as shown by the dynamics of CD20+ and CD79a+ cells. There was no significant difference in VLs between CD20-depleted AGMs and control monkeys: peak VLs ranged from 107 to 108 copies/ml; set-point values were 104 to 105 SIV RNA copies/ml. Levels of acute mucosal CD4+ T-cell depletion were similar for treated and nontreated animals. SIVagm seroconversion was delayed for the CD20-depleted AGMs compared to results for the controls. There was a significant difference in both the timing and magnitude of neutralizing antibody responses for CD20-depleted AGMs compared to results for controls. CD20 depletion significantly altered the histological structure of the germinal centers in the LNs and Peyer''s patches. Our results, although obtained with a limited number of animals, suggest that humoral immune responses play only a minor role in the control of SIV viral replication during acute and chronic SIV infection in natural hosts.In marked contrast to pathogenic human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) infections of humans and macaques, which are characterized by the constant progression to AIDS in a variable time frame (26), African monkey species naturally infected with SIV are generally spared from any signs of disease (reviewed in references 53 and 71).There are currently three animal models of SIV infection in natural hosts: SIVagm infection of African green monkeys (AGMs), SIVsmm infection of sooty mangabeys, and SIVmnd-1 and SIVmnd-2 infection of mandrills (53, 71). SIV infection in natural hosts is characterized by the following: (i) active viral replication, with set-point viral loads (VLs) similar to or even higher than those found in pathogenic infections (44-46, 49, 50, 52, 61-63); (ii) transient depletion of peripheral CD4+ T cells during primary infection, which rebound to preinfection levels during chronic infection (12, 30, 44-46, 49, 62); (iii) significant CD4+ T-cell depletion in the intestine, which can be partially restored during chronic infection in spite of significant viral replication (21, 48); (iv) low levels of CD4+ CCR5+ cells in blood and tissues (47); (v) transient and moderate increases in immune activation and T-cell proliferation during acute infection, with a return to baseline levels during the chronic phase (44-46, 49, 50, 52, 61-63), as a result of an anti-inflammatory milieu which is rapidly established after infection (14, 30); and (vi) no significant increase in CD4+ T-cell apoptosis during either acute or chronic infection (37, 48), thus avoiding enteropathy and microbial translocation, which control excessive immune activation and prevent disease progression by allowing CD4+ T-cell recovery in the presence of high VLs (21, 48). Hence, the current view is that the main reason behind the lack of disease progression in natural African hosts lies in a better adaptation of the host in response to the highly replicating virus. A better understanding of the mechanisms underlying the lack of disease in natural hosts for SIV infection may provide important clues for understanding the pathogenesis of HIV infection (53, 71).To date, it is still unknown whether or not immune responses are responsible for the lack of disease progression in natural hosts, since data are scarce. Studies of cellular immune responses are significantly more limited than is the case with pathogenic infection, and although not always in agreement (3, 13, 28, 29, 73, 76), their convergence point is that cellular immune responses are not essentially superior to those observed in pathogenic infections (3, 13, 28, 29, 73, 76). This observation is not surprising in the context of the high viral replication in natural hosts. Data are even scarcer on the role of humoral immune responses in the control of disease progression in natural hosts. However, several studies reported that anti-SIV antibody titers are lower in SIV infections of natural hosts, with a lack of anti-Gag responses being characteristic of natural SIV infections in African nonhuman primates (1, 6, 24, 25, 42, 43, 71). Because the viral replication in SIVagm-infected AGMs is of the same magnitude or higher than that in pathogenic infections of rhesus macaques (RMs), it has been hypothesized that these high VLs may be a consequence of the lower antibody titers. Moreover, a recent study has also shown that B cells in lymph nodes (LNs) of AGMs are activated at an earlier time point than is the case for SIVmac251-infected RMs, which implies that humoral immune responses may be important in controlling SIV replication in the natural hosts (9). Conversely, it has been shown that passively transferring immunoglobulins from animals naturally infected with SIVagm prior to infection with a low dose of SIVagm did not prevent infection in AGMs (42, 60), which is in striking contrast to results in studies of pathogenic infections, which convincingly demonstrated with animal models that intravenously administered or topically applied antibodies can protect macaques against intravenous or mucosal simian-human immunodeficiency virus challenge (34-36, 54, 72).Previous CD20+ B-cell-depletion studies during pathogenic RM infections have indicated that humoral immune responses may be important for controlling both the postpeak VL and disease progression (38, 57). However, these studies used strains that are highly resistant to neutralization (SIVmac251 and SIVmac239), making it difficult to assess the role that antibodies have in controlling SIV replication and disease progression. Moreover, our recent results suggested a limited impact of humoral immune responses in controlling replication of a neutralization-sensitive SIVsmm strain in rhesus macaques (18).To investigate the effect that CD20+ B cells and antibodies have on SIV replication in natural hosts, we have depleted CD20+ B cells in vivo in AGMs infected with SIVagm.sab92018. We assessed the impact of humoral immune responses on the control of viral replication and other immunological parameters, and we report that ablating humoral immune responses in SIVagm-infected AGMs does not significantly alter the course of virus replication or disease progression.  相似文献   
895.
AimsEstrogen receptor activation has been shown to reduce body weight and produce conditioned taste avoidance (CTA) when estradiol administration is paired with a novel tastant. This study determined if the selective estrogen receptor modulators tamoxifen and raloxifene, which effectively prevent and treat breast cancer, can induce a CTA and alter body weight in ovariectomized (OVX)-female rats.Main methodsDuring conditioning, OVX-female rats were injected with tamoxifen, raloxifene, 17β-estradiol or vehicle, or were uninjected, prior to drinking 0.3 M sucrose in a lickometer. Immediately following sucrose access, alterations in locomotor activity and thigmotaxis (anxiety) were assessed in an open field apparatus. Conditioned drug effects on drinking, locomotor activity and anxiety were examined on a separate test day.Key findingsOur results suggest that both tamoxifen and raloxifene produce CTA that is similar to that produced by estradiol. Both the number and size of bursts of licking were significantly reduced, as well as body weight gain, in OVX-female rats treated with tamoxifen or raloxifene.SignificanceThe results of the present study suggest that tamoxifen and raloxifene may have the potential to produce CTA in breast cancer patients receiving chemoprevention care.  相似文献   
896.
897.
Nitric oxide (NO) has been implicated as an important signaling molecule in the insulin-independent, contraction-mediated glucose uptake pathway and may represent a novel strategy for blood glucose control in patients with type 2 diabetes (T2DM). The current study sought to determine whether the NO donor, sodium nitroprusside (SNP) increases glucose uptake in primary human skeletal muscle cells (HSkMC) derived from both healthy individuals and patients with T2DM. Vastus lateralis muscle cell cultures were derived from seven males with T2DM (aged 54 ± 2 years, BMI 31.7 ± 1.2 kg/m2, fasting plasma glucose 9.52 ± 0.80 mmol/L) and eight healthy individuals (aged 46 ± 2 years, BMI 27.1 ± 1.5 kg/m2, fasting plasma glucose 4.69 ± 0.12 mmol/L). Cultures were treated with both therapeutic (0.2 and 2 μM) and supratherapeutic (3, 10 and 30 mM) concentrations of SNP. An additional NO donor S-nitroso-N-acetyl-d,l-penicillamine (SNAP) was also examined at a concentration of 50 μM. Glucose uptake was significantly increased following both 30 and 60 min incubations with the supratherapeutic SNP treatments (P = 0.03) but not the therapeutic SNP doses (P = 0.60) or SNAP (P = 0.54). There was no difference in the response between the healthy and T2DM cell lines with any treatment or dose. The current study demonstrates that glucose uptake is elevated by supratherapeutic, but not therapeutic doses of SNP in human primary skeletal muscle cells derived from both healthy volunteers and patients with T2D. These data confirm that nitric oxide donors have potential therapeutic utility to increase glucose uptake in humans, but that SNP only achieves this in supratherapeutic doses. Further study to delineate mechanisms and the therapeutic window is warranted.  相似文献   
898.
During pre-mRNA splicing, the spliceosome must configure the substrate, catalyze 5′ splice site cleavage, reposition the substrate, and catalyze exon ligation. The highly conserved U2/U6 helix I, which adjoins sequences that define the reactive sites, has been proposed to configure the substrate for 5′ splice site cleavage and promote catalysis. However, a role for this helix at either catalytic step has not been tested rigorously and previous observations question its role at the catalytic steps. Through a comprehensive molecular genetic study of U2/U6 helix I, we found that weakening U2/U6 helix I, but not mutually exclusive structures, compromised splicing of a substrate limited at the catalytic step of 5′ splice site cleavage, providing the first compelling evidence that this helix indeed configures the substrate during 5′ splice site cleavage. Further, mutations that we proved weaken only U2/U6 helix I suppressed a mutation in PRP16, a DEAH-box ATPase required after 5′ splice site cleavage, providing persuasive evidence that helix I is destabilized by Prp16p and suggesting that this structure is unwound between the catalytic steps. Lastly, weakening U2/U6 helix I also compromised splicing of a substrate limited at the catalytic step of exon ligation, providing evidence that U2/U6 helix I reforms and functions during exon ligation. Thus, our data provide evidence for a fundamental and apparently dynamic role for U2/U6 helix I during the catalytic stages of splicing.  相似文献   
899.
ABSTRACT   The themes, trends, and significant events of 2008 demonstrate that anthropology has established a new foothold in the public sphere—one that makes the most of novel forms of communication to reach far beyond the ivory tower to disseminate knowledge widely and freely. This review focuses on six topical areas of robust anthropological research in 2008 that also addressed some of the year's most pressing problems and issues, including the following: (1) war and peace; (2) climate change; (3) natural, industrial, and development-induced disaster recovery; (4) human rights; (5) health disparities; and (6) racial understanding, politics, and equity in the United States. It concludes by addressing some emerging issues in 2009 that especially require anthropological attention and insight, if we are to move beyond "business as usual."[Keywords: practicing anthropology, public anthropology, 2009 trends, anthropological impacts]  相似文献   
900.
Three genetic loci for lung cancer risk have been identified by genome-wide association studies (GWAS), but inherited susceptibility to specific histologic types of lung cancer is not well established. We conducted a GWAS of lung cancer and its major histologic types, genotyping 515,922 single-nucleotide polymorphisms (SNPs) in 5739 lung cancer cases and 5848 controls from one population-based case-control study and three cohort studies. Results were combined with summary data from ten additional studies, for a total of 13,300 cases and 19,666 controls of European descent. Four studies also provided histology data for replication, resulting in 3333 adenocarcinomas (AD), 2589 squamous cell carcinomas (SQ), and 1418 small cell carcinomas (SC). In analyses by histology, rs2736100 (TERT), on chromosome 5p15.33, was associated with risk of adenocarcinoma (odds ratio [OR] = 1.23, 95% confidence interval [CI] = 1.13–1.33, p = 3.02 × 10−7), but not with other histologic types (OR = 1.01, p = 0.84 and OR = 1.00, p = 0.93 for SQ and SC, respectively). This finding was confirmed in each replication study and overall meta-analysis (OR = 1.24, 95% CI = 1.17–1.31, p = 3.74 × 10−14 for AD; OR = 0.99, p = 0.69 and OR = 0.97, p = 0.48 for SQ and SC, respectively). Other previously reported association signals on 15q25 and 6p21 were also refined, but no additional loci reached genome-wide significance. In conclusion, a lung cancer GWAS identified a distinct hereditary contribution to adenocarcinoma.  相似文献   
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