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21.
Obesity is a multifactorial metabolic disorder characterized by low grade chronic inflammation. Rare and novel mutations in genes which are vital in several key pathways have been reported to alter the energy expenditure which regulates body weight. The TP53 or p53 gene plays a prominent role in regulating various metabolic activities such as glycolysis, lipolysis, and glycogen synthesis. Recent genome-wide association studies reported that tumor suppressor gene p53 variants play a critical role in the predisposition of type 2 diabetes and obesity. Till date, no reports are available from the Arabian population; hence the present study was intended to assess the association between p53 variants with risk of obesity development in the Saudi population. We have selected three p53 polymorphisms, rs1642785 (C > G), and rs9894946 (A > G), and rs1042522 (Pro72Arg; C > G) and assessed their association with obesity risk in the Saudi population. Phenotypic and biochemical parameters were also evaluated to check their association with p53 genotypes and obesity. Genotyping was carried out on 136 obese and 122 normal samples. We observed that there is significantly increased prevalence p52 Pro72Arg (rs1042522) polymorphism in obese persons when compared to controls at GG genotype in overall comparison (OR: 2.169, 95% CI: 1.086-4.334, p = 0.02716). Male obese subjects showed three-fold higher risk at GG genotype (OR: 3.275, 95% CI: 1.230-8.716, p = 0.01560) and two-fold risk at G allele (OR: 1.827, 95% CI: 1.128-2.958, p = 0.01388) of p53 variant Pro72Arg respectively. This variant has also shown significant influence on cholesterol, LDL level, and random insulin levels in obese subjects (p ≤ 0.05). In conclusion, p53 Pro72Arg variant is highly prevalent among obese individuals and may act as a genetic modifier for obesity development among Saudis.  相似文献   
22.
A comprehensive GC-MS analysis of 8 Ipomoea species belonging to the subgenus Quamoclit, section Mina revealed that the members of this taxon form combinations of two necine bases with rare necic acids resulting in unique pyrrolizidine alkaloids. The occurrence and diversity of these metabolites show remarkable variations: Some species, especially Ipomoea hederifolia and Ipomoea lobata, are able to synthesize a large number of alkaloids whereas others, especially Ipomoea coccinea and Ipomoea quamoclit, are poor synthesizers with only a few compounds. However, these metabolites are apparently chemotaxonomic markers of this infrageneric taxon in general. They represent either esters of (-)-platynecine (altogether 48 ipangulines and 4 further esters including results of a previous study) or esters of (-)-trachelanthamidine, an additional novel structural type called minalobines (altogether 21 alkaloids). Both types are characterized by section-specific rare necic acids, e.g., ipangulinic/isoipangulinic acid, phenylacetic acid. The alkaloids of Ipomoea cholulensis, I. coccinea, I. hederifolia, Ipomoea neei, and Ipomoea quamoclit were mono and diesters of platynecine. Minalobines turned out to be metabolites of I. lobata (Cerv.) Thell. (syn.: Mina lobata Cerv.) lacking ipangulines. The major alkaloid of this species, minalobine R, has been isolated and identified as 9-O-(threo-2-hydroxy-2-methyl-3-phenylacetoxy-butyryl)-(-)-trachelanthamidine on the basis of spectral data. Apparently only two of the species included in this study, Ipomoea cristulata and Ipomoea sloteri, are able to synthesize both, ipangulines as well as minalobines. Minalobine O could be isolated as a major alkaloid of I. cristulata, its structure has been established as 9-O-(erythro-2-hydroxy-2-methyl-3-tigloyloxy-butyryl)-(-)-trachelanthamidine on the basis of spectral data.  相似文献   
23.
Tribe Fabeae consists of five genera, Lathyrus (160 spp.), Lens (4–6 spp.), Pisum (2–3 spp.), Vavilovia (monotypic), and Vicia (160 spp.), and shows a diversity in stylar features. At least six different stylar types are known in the tribe. In order to reclassify the tribe at the rank of genus, we tried to discover apomorphies in stylar features using a molecular phylogenetic study. We surveyed internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA of representative species, selected from each group having different types of styles in the tribe. We paid particular attention in sampling to members of Vicia section Vicilla, as stylar features are heterogeneous within this section. Consequently, our sample set included 15 species of section Vicilla, 23 species of other Fabeae, and two species of Trifolieae, which were used as a sister group of Fabeae. Based on our analysis, we found that a laterally compressed style and an abaxially tufted hairy style would be advanced against a dorsiventrally compressed style and an evenly hairy style, respectively, in genus Vicia. The species group, which shares the latter apomorphy, is composed of 56 species and was dispersed into 11 sections of two subgenera in the recent system of genus Vicia. We consider future revision of Fabeae should treat this species group as a single higher taxon.  相似文献   
24.
Amanita curtipes and A. ponderosa are two Mediterranean taxa sharing a number of morphological features as well as their habitat. Their synonymy or variety status has been proposed by several authors. To clarify this taxonomic issue we have sequenced the D1-D2 domains of the 28S rRNA gene as well as the complete ITS1-5.8S-ITS2 region of several specimens of the two species collected in Spain, and aligned these sequences with those from other Amanita species. Molecular phylogenetic analysis based on the two regions revealed that A. ponderosa and A. curtipes are clearly distinct species. The distribution of Amanita species in the phylogenetic trees was consistent with the division of the genus in subgenera and sections as proposed by previous authors. Sequences of A. ponderosa and A. curtipes were grouped in a monophyletic cluster together with other species of the section Amidella. However, A. ponderosa was closer to other species in the section, such as A. peckiana and A. volvata, than to A. curtipes. We also indicate the macromorphological characters that are most useful to reliably distinguish A. ponderosa and A. curtipes.  相似文献   
25.
We present a synoptic assessment intended to maximize the benefits to wetland species biodiversity gained through Clean Water Act regulatory efforts within 225 sub-basins in Missouri, Iowa, Nebraska and Kansas (US Environmental Protection Agency, Region 7), USA. Our assessment provides a method for prioritizing sub-basins potentially critical for supporting wetland species biodiversity and may assist environmental managers and conservationists constrained by limited resources. We prioritize sub-basins based on the projected increase in the risk of wetland species extirpation across Region 7 that would be avoided by applying a unit of regulatory protection effort within a sub-basin. Because the projected increase in risk avoided per unit effort has not been directly measured, we represent this quantity with an index of indicators drawn from readily available data. A conceptual model incorporating landscape and anthropogenic factors guides index development via a series of simple benefit-cost equations. We rank and map the final index scores to show the relative priority among sub-basins for protection effort. High priority sub-basins appear to be concentrated along the major river systems within the region, where sensitive wetland species and intensive agriculture tend to coincide. Protection of wetland species biodiversity is an important, but not exclusive, attribute around which priorities should be set. Nevertheless, incorporation of our results into management strategies should allow managers to cast their local decisions in the context of regional scale maintenance of wetland species biodiversity, increasing ecological benefits for a given protection effort.  相似文献   
26.
Acharan sulfate is a glycosaminoglycan (GAG), having the structure →4)-2-acetamido-2-deoxy-α- -glucopyranose(1→4)-2-sulfo-α- -idopyranosyluronic acid (1→, isolated from the body of the giant African snail Achatina fulica. This GAG represents 3–5% of the dry weight of this snail's soft body tissues. Frozen sections and polyester wax sections of the snail's body were stained by Alcian blue-periodic acid-Schiff's reagent (PAS) to localize acharan sulfate. Alcian blue staining indicated that GAG was mainly secreted into the outer surface of the body from internal granules. A highly mucous material was collected and treated and the acharan sulfate was recovered by ethanol and cetyl pyridinium chloride precipitation. Crude acharan sulfate was purified by DEAE-Sephacel ion-exchange chromatography. Depolymerization of intact mucus and purified acharan sulfate fractions by heparin lyase II (heparitinase I) from Flavobacterium heparinum produced an unsaturated disaccharide as a major product, establishing the repeating unit of acharan sulfate. These results demonstrate that mucus in the granule and secreted to the outside of the body is composed entirely of acharan sulfate.  相似文献   
27.
Mechanical forces are an important contributor to cell fate specification and cell migration during embryonic development in animals. Similarities between embryogenesis and regeneration, particularly with regards to pattern formation and large-scale tissue movements, suggest similarly important roles for physical forces during regeneration. While the influence of the mechanical environment on stem cell differentiation in vitro is being actively exploited in the fields of tissue engineering and regenerative medicine, comparatively little is known about the role of stresses and strains acting during animal regeneration. In this review, we summarize published work on the role of physical principles and mechanical forces in animal regeneration. Novel experimental techniques aimed at addressing the role of mechanics in embryogenesis have greatly enhanced our understanding at scales from the subcellular to the macroscopic – we believe the time is ripe for the field of regeneration to similarly leverage the tools of the mechanobiological research community.  相似文献   
28.
The taxonomical history of the woody group(peonies) in the genus Paeonia is reviewed in the present paper. The group is endemic to China, but Paeonia suffruticosa is commonly cultivated throughout the north temperate region and has long been known as “the King of Flowers” in China. However, the taxonomy of the group had been neglected before the 1990' s. Since 1990, a number of new species and subspecies have been published. With the support from the National Geographic Society, the senior author of the present paper and his coworkers have made expeditions to all parts of the distribution area of the group, visited all the type localities and sampled a total of 64 populations. Based on the character analysis and examination of the type specimens or photos, each taxon is reviewed with its name checked nomenclaturally, and finally the taxonomy of the whole group is revised. As a result, eight species, three of which each contains two subspecies, are recognized. They are Paeonia suffruticosa Andrews subsp. suffruticosa and subsp. yinpingmudan D. Y. Hong, K. Y. Pan et Z. W. Xie, P. jishanensis T. Hong et W. Z. Zhao, P. qiui Y. L. Pei et D. Y. Hong, P. ostii T. Hong et J. X. Zhang, P. rockii (S. G. Haw et L. A. Lauener )T. Hong et J. J. Li subsp. rockii and subsp. taibaishanica D. Y. Hong, P. decomposita Hand.-Mazz. Subsp. decomposita and subsp. rotundiloba D. Y. Hong, P. delavayi Franeh. and P. ludlowii (Stern et Taylor)D. Y. Hong. P. baokangensis Z. L. Dai et T. Hong and P. yananensis T. Hong et M. R. Li are considered as hybrids between P. rockii and P. qiui and between P. rockii and P. jishanensis respectively. In addition, the reduction of a number of names recently published to synonyms is explained.  相似文献   
29.
A new orchid, Disa albomagentea, is described from the Hottentots Holland Mountains in the Western Cape Province of South Africa. It is an obligately fire-dependent species closely related to Disa obtusa (sect. Disella), from which it can be easily distinguished by the larger flowers, i.e. galea 7-9 mm long versus 4-7 mm long, which are patent and bicoloured, i.e. magenta, white and not spotted versus purple brown, white to cream to greenish, and variously purple spotted. It appears to be endemic to seeps and marshes on the high peaks.  相似文献   
30.
报道了中国四川报春花属(Primula L.)一新种——小繸瓣报春(P.hydrocotylifolia G.Hao,C.M.Hu&Y.Xu)。小繸瓣报春植株无毛、无粉,叶片多少呈圆形,具纤细的叶柄,开花期叶丛基部无鳞片,球形蒴果藏于宿存花萼,成熟时裂成不规则碎片,显然属于脆蒴报春组(sect.Petiolares Pax)革叶报春亚组(subsect.Chartacea W.W.Sm.&Forrest),并与该亚组的川西繸瓣报春(P.veitchiana Petitm.)最为接近,但后者植物体的各部分均远大于此新种,花序多花,花亦较大,二者之间无过渡类型。  相似文献   
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