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991.
It has been very recently shown how naturally occurring oxyprenylated coumarins are effective modulators of melanogenesis. In this short communication we wish to generalize the potentialities as skin tanning or whitening agents of a wider panel of natural and semisynthetic aromatic compounds, including coumarins, cinnamic and benzoic acids, cinnamaldehydes, benzaldehyde, and anthraquinone derivatives. A total number of 43 compounds have been tested assaying their capacity to inhibit or stimulate melanin biosynthesis in cultured murine Melan A cells. The wider number of chemicals herein under investigation allowed to depict a detailed structure-activity relationship, as the following: (a) benzoic acid derivatives are slightly pigmenting agent, for which the effect is more pronounced in compounds with longer O-side chains; (b) independently from the type of substitution, cinnamic acids are able to increase melanin biosynthesis, while benzaldehydes are able to decrease it; (c) coumarins with a 3,3-dimethylallyl or shorter skeletons as substituents in position 7 are tanning agents, while coumarins with farnesyloxy groups are whitening ones; (d) double oxyprenylation in position 6 and 7 and 3,3-dimethylallyl or geranyl skeletons have slight depigmenting capacities, while farnesyl skeletons tend to marginally increase the tanning effect; (e) the presence of electron withdrawing groups (acetyl, COOH, and -Cl) and geranyl or farnesyl oxyprenylated chains respectively in positions 3 and 7 of the coumarin nucleus lead to a whitening effect, and finally (f) oxyprenylated anthraquinones have only a weak depigmenting capacity. 相似文献
992.
克什米尔蜜蜂病毒(Kashmir bee virus, KBV)作为一种毒力较强的蜜蜂急性病毒,自20世纪70年代被分离鉴定以来,已发现其广泛侵染世界各地的东方蜜蜂Apis cerana和西方蜜蜂Apis mellifera。KBV在蜂群内通过垂直和水平两种方式进行传播,且狄斯瓦螨Varroa destructor在其中扮演着重要角色,这使得KBV的分布范围持续扩散。目前已报道的病毒宿主除蜜蜂外,其还可侵染熊蜂、胡蜂等多种野生授粉昆虫。同时,KBV作为一种典型的双顺反子病毒科病毒,由于其在分子生物学上与同科的蜜蜂急性麻痹病毒(acute bee paralysis virus, ABPV)和以色列急性麻痹病毒(Israeli acute paralysis virus, IAPV)间的高相似性,对该病毒流行性的调查与检测、分类等研究的混乱局面也接踵而至。本文对过去40多年来的KBV相关研究进行综述,以期为KBV及类似昆虫病毒的后续研究提供一定的参考和借鉴,促进养蜂业的健康发展。 相似文献
993.
Yu-Yon Kim Jaeyul Choi Kyungjin Choi Changhee Park Young Hoon Kim Kwee Hyun Suh Young Jin Ham Sun Young Jang Kyu-Hang Lee Kwang Woo Hwang 《Bioorganic & medicinal chemistry letters》2019,29(2):271-275
Colony stimulating factor-1 receptor (CSF-1R or FMS) and it ligand, CSF-1, signaling regulates the differentiation and function of tumor-associated macrophages (TAMs) that play an important role in tumor progression. Derivatives of thieno[3,2-d]pyrimidine were synthesized and evaluated as kinase inhibitors of FMS. The most representative compound 21 showed strong activity (IC50?=?2?nM) against FMS kinase and served as candidate for proof of concept. Anti-tumor activity alone and/or in combination with paclitaxel was examined via a tumor cell growth inhibition assay and via an in vitro tumor invasion assay using human breast adenocarcinoma cells. 相似文献
994.
Jana Dobelmann Alana Alexander James W. Baty Neil J. Gemmell Monica A. M. Gruber Oliver Quinn Tom Wenseleers Philip J. Lester 《Molecular ecology》2019,28(14):3324-3338
Despite the mitochondrion's long‐recognized role in energy production, mitochondrial DNA (mtDNA) variation commonly found in natural populations was assumed to be effectively neutral. However, variation in mtDNA has now been increasingly linked to phenotypic variation in life history traits and fitness. We examined whether the relative fitness in native and invasive common wasp (Vespula vulgaris) populations in Belgium and New Zealand (NZ), respectively, can be linked to mtDNA variation. Social wasp colonies in NZ were smaller with comparatively fewer queen cells, indicating a reduced relative fitness in the invaded range. Interestingly, queen cells in this population were significantly larger leading to larger queen offspring. By sequencing 1,872 bp of the mitochondrial genome, we determined mitochondrial haplotypes and detected reduced genetic diversity in NZ. Three common haplotypes in NZ frequently produced many queens, whereas the four rare haplotypes produced significantly fewer or no queens. The entire mitochondrial genome for each of these haplotypes was sequenced to identify polymorphisms associated with fitness reduction. We found 16 variable sites; however, no nonsynonymous mutation that was clearly causing impaired mitochondrial function was detected. We discuss how detected variants may alter secondary structures, gene expression or mito‐nuclear interactions, or could be associated with nuclear‐encoded variation. Whatever the ultimate mechanism, we show reduced fitness and mtDNA variation in an invasive wasp population as well as specific mtDNA variants associated with fitness variation within this population. Ours is one of only a few studies that confirm fitness impacts of mtDNA variation in wild nonmodel populations. 相似文献
995.
目的:血清促甲状腺激素(TSH)在甲状腺乳头状癌(PTC)中的作用及机制尚不明确,本研究主要探讨TSH对甲状腺细胞系及乳头状癌细胞系的作用。方法:体外培养人甲状腺细胞系和乳头状癌细胞系,分别给予不同剂量(0 mU/L、5 mU/L及20 mU/L)的TSH干预。通过MTS及流式细胞术,观察TSH对甲状腺及乳头状癌细胞系增殖和细胞周期的作用;通过RNA-seq、ELISA检测TSH对细胞因子的影响;通过实时荧光定量PCR及Western blot寻找潜在的作用靶点。结果:MTS及流式细胞术结果显示,TPC-1和Nthy-ori-3-1细胞经TSH干预后增殖指数下降,20 mU/L浓度的TSH干预组细胞周期缩短。ELISA结果显示TPC-1中TSH下调CXCL8,上调CXCL10,而CXCL12的表达无明显变化。在Nthy-ori-3-1细胞中CXCL8和CXCL10的表达也观察到类似的结果,但CXCL12表达受到TSH的抑制。TSH可使Nthy-ori-3-1和Bcpap细胞中细胞命运决定因子(DACH1)的表达呈剂量依赖性上调,且TSH可抑制Bcpap中BRAF(V600E)以及Nthy-ori-3-1和TPC-1中BRAF的表达。结论:综上所述,我们并未发现TSH对甲状腺癌细胞有明显的促肿瘤作用。相反,本研究提示TSH可能呈部分抗癌作用。因此,TSH对甲状腺的致癌作用仍有待进一步研究。 相似文献
996.
摘要 目的:探究III期结直肠癌手术患者接受奥沙利铂联合卡培他滨治疗后血清粒细胞集落刺激因子(G-CSF)、人脂联素(ADPN)水平的变化,分析血清G-CSF、ADPN水平与肠道菌群失调的相关性。方法:选择2021年1月至2021年12月于我院接受手术治疗的220例III期结直肠癌患者为研究对象,均对其联合应用奥沙利铂与卡培他滨进行治疗,分析治疗前后患者血清G-CSF、ADPN水平变化,将入组患者按照肠道菌群情况分为肠道正常组(n=80)、菌群失调I度组(n=90)、菌群失调II度组(n=50),分析肠道菌群失调对入组患者治疗前后血清G-CSF、ADPN水平的影响,最后评估血清G-CSF、ADPN水平与肠道菌群失调的相关性。结果:(1)治疗后入组患者血清G-CSF、ADPN水平均较治疗前出现了明显的降低,前后比较有差异(P<0.05);(2)治疗后菌群正常组患者血清G-CSF、ADPN水平明显低于菌群失调I度组,菌群失调I度组明显低于菌群失调II度组,各组间血清G-CSF、ADPN水平有差异(P<0.05);(3)不同肠道菌群失调组患者肠道菌群数量存在差异,患者肠道菌群失调情况越严重,其肠球菌数量越高,乳杆菌数量越低(P<0.05);(4)血清G-CSF、ADPN水平与乳杆菌数量呈现负相关(r=-0.872、-0.781,P<0.05),与肠球菌数量呈现正相关(r=0.772、0.819,P<0.05)。结论:Ⅲ期结直肠癌行手术治疗患者术后联用奥沙利铂与卡培他滨可以显著降低其血清G-CSF、ADPN水平,且其降低程度与患者肠道菌群失调情况相关,提示可以考虑将调节结直肠癌患者肠道菌群作为降低患者化疗后炎性反应措施之一推广于临床。 相似文献
997.
998.
Yoshizato K 《Development, growth & differentiation》2007,49(2):171-184
The liver is one of the few organs that is capable of completely regenerating itself without using a stem cell population. When damaged, growth factors and cytokines are released, stimulating terminally differentiated adult hepatocytes and making them re-enter the cell cycle. We have been developing a series of studies on the growth potential of rat and human hepatocytes to identify a population of hepatocytes that is responsible for the regeneration of the injured liver. For this purpose, we established an appropriate culture method for hepatocytes by which growth and differentiation capacities are practically examined under various experimental conditions. This in vitro assay system allows us to identify small hepatocytes that are prominently replicative compared to large hepatocytes. Non-parenchymal cells play critical roles in the proliferation of small hepatocytes. These hepatocytes are present in both rat and human liver and are located in portal regions there. Phenotypic features were examined at morphological and gene/protein levels in detail, which showed the phenotypic plasticity in vitro. Mammalian liver includes a population of small hepatocytes in normal adults with a minute occupancy rate. We speculate that small hepatocytes play a role in regenerating the injured liver and in compensating for apoptotic hepatocytes in the physiological turnover of hepatocytes. 相似文献
999.
Watanabe M Uchida K Nakagaki K Kanazawa H Trapnell BC Hoshino Y Kagamu H Yoshizawa H Keicho N Goto H Nakata K 《FEBS letters》2007,581(10):2017-2021
Anti-cytokine autoantibodies in healthy individuals have been widely reported but the occurrence is variable and inconstant. We hypothesized that cytokine-binding in vivo may explain their variable and infrequent detection. Therefore, we focused on the detection of the cytokine-autoantibody complexes and found that anti-cytokine autoantibody to IL-2, IL-8, tumor necrosis factor-alpha, vascular endothelial growth factor and granulocyte-colony stimulating factor were present in all 15 individuals evaluated, while those to IL-3, osteopontin and macrophage-colony stimulating factor were not detected in anyone. Autoantibodies against IL-4, IL-6, IL-10, and interferon-gamma were variously detected. Thus, we discovered that anti-cytokine autoantibodies to multiple cytokines are ubiquitous in healthy individuals. 相似文献
1000.
Some loosely colonial species scatter their nests within a colony. Most studies on mechanisms that generate such scattered
nests within a colony have primarily focused on the measurement of distance related to the intensity of interactions among
conspecific neighbors. However, these interactions can change not only with distance between nests but also with other factors.
In particular, whether the nest is hidden from neighbors can strongly affect the intensity of interaction for birds that usually
use sight for communication. To show the possible benefit of nesting at sites hidden from neighboring nests, we studied the
nest arrangements and settlement patterns within a barn swallow colony. We tested whether the swallows prefer nesting at sites
hidden from neighboring nests in cattle barns that are often used as colony sites by the swallows in Japan. We found that
the sides of ceiling beams hidden from neighbors were preferred as nesting sites. A randomization test suggested that the
rectangular sections occupied by swallows were not spaced out within a colony. The results suggested that the swallows preferred
nesting sites hidden from their neighbors and did not space out their nests within a colony. This paper also refutes intraspecific
brood parasitism as a plausible function of this behavior. 相似文献