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21.
本文首先根据眼小叶蝉族Alebrini讨论翅的命名,接着是眼小叶蝉属Alebra Fieb.和东半球眼小叶蝉族各属的评论。Homa elongata Kato移入属AsialebraDwor.,Shaddai distanti Dwor.是S.typicus Dist.的异名。描述了6个新种,即Sobralacapreola,S.clara,Orientalebra drawidana,Afralebra melichari,A.youngi,A.paolii. 本文引言部分讨论小叶蝉亚科Typhlocybinae翅的形态学,正文为分类部分。 在描述内部构造以及端节、头、和胸部背面时,使用习惯术语。 新种模式标本系列保存于下列博物馆中;正模的保管者在有关描述中最先提到: SMTD——德国得累斯顿,国家动物学博物馆。 BMNH——英国伦敦,英国自然历史博物馆。 USNM——美国华盛顿,美国国家博物馆。 MM——捷克斯洛伐克Brno,Moravian博物馆。 相似文献
22.
Gal Bitan Irena Zeltser Gerardo Byk David Halle Yaffa Mashriki Evgenia V. Gluhov Inna Sukhotinsky Menachem Hanani Zvi Selinger Chaim Gilon 《Journal of peptide science》1996,2(4):261-269
Novel backbone-to-side chain and backbone-to-backbone cyclic analogues of substance P (SP) were prepared by solid-phase synthesis and screened for biological activity. An analogue containing a thioether- lactam ring between positions 9 and 11 showed an EC50 value of 20nM toward the neurokinin 1 (NK-1) and was inactive toward the NK-2 and NK-3 receptors. On the other hand, in a multiple backbone cyclic peptide library of similar analogues, in which the sulphur was excluded from the ring, very low activity was detected. The activity was re-evaluated and was found to be even lower (EC50=0.11 mM ) than the previously published data. These results indicate that the thioether moiety has a crucial role in receptor activation. The results also show tolerance of the NK-1 receptor, but not NK-2 or NK-3, to cyclization of the C-terminal portion of the SP6–11 hexapeptide. 相似文献
23.
G Zummo A Palma G Peri B Valentino 《Bollettino della Società italiana di biologia sperimentale》1984,60(1):153-156
Many Authors described primary 9+0 cilia in different tissue of different animal species. In relation to the study on the ultrastructural architecture of the embryonic heart of a elasmobranch "Scyllium stellare", we saw some primary 9+0 cilia in very undifferentiated heart tissue. The hearts dissected from the Scyllium stellare embryo at 6 months of gestation, were processed for the observations at the transmission electron microscope. The cilia are found in deep invagination of the plasma membrane, near the Golgi complex and in the perinuclear region. Various functions have been postulated for the primary 9+0 cilia. 相似文献
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Mario Maggi Guido Fantoni Alessandro Peri Stefano Giannini Maria Luisa Brandi Claudio Orlando Mario Serio 《The Journal of steroid biochemistry and molecular biology》1991,40(4-6):481-491
Oxytocin (OT) and V1 vasopressin (VP) receptors are present simultaneously in several tissues, including the uterus. In myometrium these receptors mediate contractility, while in endometrium they mediate the release of other uterotonic substances as endothelin (ET). In rabbit myometrium, estrogens increase, while progesterone blunts neurohypophysial hormone receptors. However, the action of sex steroids on OT and V1 VP receptors differs in terms of the ED50 and maximal effect. Therefore, at parturition, only OT receptors show a dramatic rise, while V1 VP receptors do not change, suggesting a major role for OT in labor. ET is a potent stimulator of uterine activity acting through specific receptors present on myometrial cells. These receptors as well as the endometrial localization of ET are modulated by sex steroids, indicating that ET might represent a paracrine regulator of uterine activity. In humans, OT but not V1 VP receptors increase as pregnancy progresses, confirming the primary relevance of OT in timing delivery. 相似文献
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Progeny produced from Bombina bombina, B. variegata, and field-collected interspecific hybrids have been analyzed for the inheritance of five enzyme loci, which are fixed for alternate alleles in the parental species. Lactate dehydrogenase (Ldh-1), NAD-dependent malate dehydrogenase (Mdh-1), creatine kinase (Ck), adenylate kinase (Ak), and glucosephosphate isomerase (Gpi) are all inherited in a Mendelian manner as codominant alleles at nuclear loci. Both parental alleles are equally functional in artificial F1 hybrids (female B. bombina×male B. variegata) at each of the loci studied. No linkage between any pair of loci was observed. Discovery of this inherited biochemical variation combined with a technique for assaying individual genotypes without killing the animals makes feasible studies of hybrid population structure heretofore impossible.This work was partly supported by the Polish Academy of Sciences within the project MR-II/6. 相似文献
28.
M. Mar Díaz-Herrero José A. del Campo Pilar Carbonero-Aguilar José M. Vega-Pérez Fernando Iglesias-Guerra Ignacio Peri?án Francisco J. Mi?ano Juan Bautista Manuel Romero-Gómez 《PloS one》2014,9(10)
Ammonia production is implicated in the pathogenesis of hepatic encephalopathy (HE), being intestinal glutaminase activity the main source for ammonia. Management of ammonia formation can be effective in HE treatment by lowering intestinal ammonia production. The use of glutaminase inhibitors represents one way to achieve this goal. In this work, we have performed a search for specific inhibitors that could decrease glutaminase activity by screening two different groups of compounds: i) a group integrated by a diverse, highly pure small molecule compounds derived from thiourea ranging from 200 to 800 Daltons; and ii) a group integrated by commonly use compounds in the treatment of HE. Results shown that THDP-17 (10 µM), a thiourea derivate product, could inhibit the intestinal glutaminase activity (57.4±6.7%). Inhibitory effect was tissue dependent, ranging from 40±5.5% to 80±7.8% in an uncompetitive manner, showing Vmax and Km values of 384.62 µmol min−1, 13.62 mM with THDP-17 10 µM, respectively. This compound also decreased the glutaminase activity in Caco-2 cell cultures, showing a reduction of ammonia and glutamate production, compared to control cultures. Therefore, the THDP-17 compound could be a good candidate for HE management, by lowering ammonia production. 相似文献
29.
F Farina F Cappello M Todaro F Bucchieri G Peri G Zummo G Stassi 《The journal of histochemistry and cytochemistry》2000,48(1):57-62
Farber's disease (FD) is a rare genetic disorder caused by ceramidase deficiency, which results in ceramide accumulation in lung, liver, colon, skeletal muscle, cartilage, and bone. Although this disease has been symptomatically characterized, little is known about its molecular pathogenetic process. Because recent studies reported that ceramide accumulation induces GD3 ganglioside formation and apoptosis, we investigated, in tissue obtained via colonoscopy from seriously involved patients, the possible involvement of ceramide in FD colonocyte destruction. Histochemical and TUNEL analyses of paraffin-embedded sections revealed that 45 +/- 4.3% of FD colonocytes showed morphological signs of apoptosis compared with the 8 +/- 2.3% of constitutive epithelial cell death. Importantly, immunohistochemical study for pro-apoptotic factors showed that GD3 accumulation co-localized with active caspase-3 and cleaved K18 in FD colon tissue. These findings provide evidence for a role of the apoptotic ceramide pathway in the pathogenesis of FD. 相似文献
30.
Erika C. Freeman Irena F. Creed Blake Jones Ann‐Kristin Bergstrm 《Global Change Biology》2020,26(9):4966-4987
The interacting effects of global changes—including increased temperature, altered precipitation, reduced acidification and increased dissolved organic matter loads to lakes—are anticipated to create favourable environmental conditions for cyanobacteria in northern lakes. However, responses of cyanobacteria to these global changes are complex, if not contradictory. We hypothesized that absolute and relative biovolumes of cyanobacteria (both total and specific genera) are increasing in Swedish nutrient‐poor lakes and that these increases are associated with global changes. We tested these hypotheses using data from 28 nutrient‐poor Swedish lakes over 16 years (1998–2013). Increases in cyanobacteria relative biovolume were identified in 21% of the study sites, primarily in the southeastern region of Sweden, and were composed mostly of increases from three specific genera: Merismopedia, Chroococcus and Dolichospermum. Taxon‐specific changes were related to different environmental stressors; that is, increased surface water temperature favoured higher Merismopedia relative biovolume in low pH lakes with high nitrogen to phosphorus ratios, whereas acidification recovery was statistically related to increased relative biovolumes of Chroococcus and Dolichospermum. In addition, enhanced dissolved organic matter loads were identified as potential determinants of Chroococcus suppression and Dolichospermum promotion. Our findings highlight that specific genera of cyanobacteria benefit from different environmental changes. Our ability to predict the risk of cyanobacteria prevalence requires consideration of the environmental condition of a lake and the sensitivities of the cyanobacteria genera within the lake. Regional patterns may emerge due to spatial autocorrelations within and among lake history, rates and direction of environmental change and the niche space occupied by specific cyanobacteria. 相似文献