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Ptychopetalum olacoides (PO) roots are used by Amazonian peoples to prepare traditional remedies for treating various central nervous system conditions in which free radicals are likely to be implicated. Following the identification of PO ethanol extract (POEE) free-radical scavenging properties in vitro, the aim of this study was to verify the in vivo antioxidant effect of POEE. Aging mice (14 months) were treated (i.p.) with saline, DMSO (20%) or POEE (100mg/kg body wt.), and the hippocampi, cerebral cortex, striata, hypothalamus and cerebellum dissected out 60 min later to measure antioxidant enzyme activities, free-radical production and damage to macromolecules. POEE administration reduced free-radical production in the hypothalamus, lead to significant decrease in lipid peroxidation in the cerebral cortex, striatum and hypothalamus, as well as in the carbonyl content in cerebellum and striatum. In terms of antioxidant enzymes, catalase activity was increased in the cortex, striatum, cerebellum and hippocampus, while glutathione peroxidase activity was increased in the hippocampus. This study suggests that POEE contains compounds able to improve the cellular antioxidant network efficacy in the brain, ultimately reducing the damage caused by oxidative stress.  相似文献   

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An established SV40-transformed cell line of Dipodomys ordii was cloned for selective loss of chromosomal material. A clone is described which has a modal chromosome number of 50 (in the normal diploid 2n=72), and has about 66% of the DNA content of normal diploid cells. Karyotype analysis shows that, although some chromosome rearrangement has taken place, 23 chromosomes are completely unpaired and 7 chromosomes are partially unpaired. Buoyant density analysis in neutral CsCl and Cs2SO4+Ag gradients of the DNA of this clone shows that there has been no selective retention or loss of any of the satellite DNA components present in D. ordii during the elimination of 34% of the genetic material.  相似文献   

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This paper deals with a detailed study of Sphenophyllum miravallis Vetter, a member of the “Sphenophyllum thonii group”. New material from the Reisbach colliery, working the “Illinger Flözzone” of the “Heusweiler Schichten” (Lower Stephanian, Saar Basin, German Federal Republic), is described morphologically and anatomically, and the species is discussed. The new material enlarges the known range of variability of the normal aspect of the foliage, i.e. the foliage of the thinner branches. Thicker stems with their aberrant polymorphous foliage, and cellular details, are described for the first time. An emended diagnosis is given. Comparisons with other species are made.

The new species Bowmanites cupulatus is introduced to accommodate fructufications most probably belonging to Sphenophyllum miravallis.

S. crenulatum Knight ex Wagner is considered to be a heterotypic synonym of S. miravallis, the latter name having priority.  相似文献   


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In this work, we studied for the first time the histology and ultrastructure of the gut of Appendicularia sicula and demonstrated the absence of any trace of anus. Appendicularians are small holoplanktonic tunicates, characterised by very fast ingestion and quick food transfer along their gut. The high production of faecal pellets released in the aqueous environment, associated with a high filtration rate, highlights their important role in marine ecosystems. Due to the absence of an anus, in contrast with other appendicularians, A. sicula, one of the smallest species, accumulates undigested faecal material within its body, with consequent extreme enlargement of its rectum. The gut, the epithelium of which is generally extremely reduced, is formed of an oesophagus, a globular stomach, thin proximal and mid-intestine, and a huge rectum. The latter, when filled with faecal material, may occupy most of the volume of the trunk in fully grown specimens. Although profoundly altered, the gut of these animals does show several similarities to that of Fritillaria (a genus of the same family, Fritillariidae), with which it has in common many features such as specialised mitochondrial pump cells. In A. sicula, the structural simplifications of organs seem to reach their extreme condition in comparison to other appendicularians.  相似文献   

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The biochemical and ultrastructural changes in "green islands" (GIs) on detached Avena sterilis leaves caused by the macrodiolide (8R,16R)-(-)-pyrenophorin in the dark were examined. In the absence of light, leaf segments retained their photosynthetic pigments for 96 h after treatment with (8R,16R)-(-)-pyrenophorin (70 muM), whereas in the untreated leaves complete senescence, loss of photosynthetic pigments and cell disorganization were observed 72 h after detachment. Proteolytic enzyme activity in treated tissues with pyrenophorin remained at low levels for 96 h after treatment and protein dissipation was lower in the treated than in the untreated. Although tissues in "GIs" seem macroscopically healthy, electron microscopy observations revealed structurally disorganized cells filled with granular, electron-dense material. Chloroplasts were severely damaged and contained a large number of plastoglobuli. Similar ultrastructural changes were also observed in A. sterilis tissues treated with the phytotoxin under illumination, indicating a mechanism operating both under illumination and in the dark.  相似文献   

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M. Weigend  A. Grger  M. Ackermann 《Flora》2005,200(6):569-591
South Andean Loasas (Blumenbachia, Caiophora, Loasa, Scyphanthus) are a monophyletic group of taxa within Loasaceae subfam. Loasoideae, comprising some 100 species, 49 of which are investigated here. They retain a many-layered testa in the mature seeds and usually have passive transfer testas with complex, spongiose wall outgrowths. Additional modifications concern the undulations of the testa epidermis, presence or absence of the outer periclinal wall, secondary sculpturing, the presence or absence of spines, warts and finally spongiose structures on the anticlinal walls of the testa epidermis and the inner periclinal wall. Seeds of the widespread “deeply pitted” type are plesiomorphic, while various subclades of South Andean Loasas have derivations underscoring their relationships and confirming the relationships found with molecular markers and other morphological characters. The genus Blumenbachia has either seeds with a many-layered testa forming longitudinal lamellae (sect. Angulatae), or balloon seeds with a loose outer testa layer and spongiose wall outgrowths on the inner periclinal walls (sect. Blumenbachia and sect. Gripidea) and is clearly monophyletic. Loasa s.str. (ser. Loasa, ser. Macrospermae, ser. Floribundae, ser. Deserticolae) is characterized by the presence of a subterminal hilum or hilar scar and one subgroup (ser. Loasa, ser. Macrospermae) by very large and heavy seeds with a collapsed testa. L. ser. Pinnatae, ser. Acaules, ser. Volubiles, Scyphanthus and Caiophora share more or less one seed types with minor modifications. Within Caiophora various derivations are observed, of which the gradual loss of the secondary sculpture of the inner periclinal wall is the most striking one. Anemochoria is the most widespread dispersal mechanism in South Andean Loasas and is achieved in at least five structurally different ways.  相似文献   

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A proteinaceous receptor associated with the melanosome fraction of Pleurodeles waltlii oocytes binds progesterone with high affinity and limited capacity (KD ≈ 5 · 10−8 M).  相似文献   

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A ‘tigrina’ mutant stock of xHaynaldoticum sardoum Meletti et Onnis grown under field conditions produced high frequency spikes with abnormal stamens and pistils. The abnormalities occurred mostly in the stamens, which frequently changed to either pseudoovaries, or leaf-shaped structures or, in extreme cases, did not form at all. The developmental abnormalities of the stamens resulted in male sterility in the whole or in part of the spike. It is proposed that the “tigrina” status changes the physiology of the plant (e.g. photosynthetic activity) in such a way that it responds with floral abnormalities brought about by environmental conditions which permit normal flower development in control (non-mutant) plants.  相似文献   

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A “long‐backed” scenario of hominin vertebral evolution posits that early hominins possessed six lumbar vertebrae coupled with a high frequency of four sacral vertebrae (7:12‐13:6:4), a configuration acquired from a hominin‐panin last common ancestor (PLCA) having a vertebral formula of 7:13:6‐7:4. One founding line of evidence for this hypothesis is the recent assertion that the “Lucy” sacrum (A.L. 288‐1an, Australopithecus afarensis) consists of four sacral vertebrae and a partially‐fused first coccygeal vertebra (Co1), rather than five sacral vertebrae as in modern humans. This study reassesses the number of sacral vertebrae in Lucy by reexamining the distal end of A.L.288‐1an in the context of a comparative sample of modern human sacra and Co1 vertebrae, and the sacrum of A. sediba (MH2). Results demonstrate that, similar to S5 in modern humans and A. sediba, the last vertebra in A.L. 288‐1an exhibits inferiorly‐projecting (right side) cornua and a kidney‐shaped inferior body articular surface. This morphology is inconsistent with that of fused or isolated Co1 vertebrae in humans, which either lack cornua or possess only superiorly‐projecting cornua, and have more circularly‐shaped inferior body articular surfaces. The level at which the hiatus' apex is located is also more compatible with typical five‐element modern human sacra and A. sediba than if only four sacral vertebrae are present. Our observations suggest that A.L. 288‐1 possessed five sacral vertebrae as in modern humans; thus, sacral number in “Lucy” does not indicate a directional change in vertebral count that can provide information on the PLCA ancestral condition. Am J Phys Anthropol 156:295–303, 2015. © 2014 Wiley Periodicals, Inc.  相似文献   

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