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Spontaneous vascular mineralization (deposition of iron or calcium salts) has been observed in marble brain syndrome, mineralizing microangiopathy, hypothyroidism, Fahr syndrome, Sturge–Weber syndrome, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, and calciphylaxis in humans and as an aging or idiopathic lesion in the brains of horses, cats, nonhuman primates, mice, rats, cattle, white-tailed deer, and dogs. Here we present a 27-y-old, adult male chimpanzee (Pan troglodytes) with spontaneous, extensive vascular mineralization localized solely to the brain. The chimpanzee exhibited tremors and weakness of the limbs, which progressed to paralysis before euthanasia. Magnetic resonance brain imaging in 2002 and 2010 (immediately before euthanasia) revealed multiple hypointense foci, suggestive of iron- and calcium-rich deposits. At necropsy, the brain parenchyma had occasional petechial hemorrhage, and microscopically, the cerebral, cerebellar and brain stem, gray and white matter had moderate to severe mural aggregates of a granular, basophilic material (mineral) in the blood vessels. In addition, these regions often had moderate to severe medial to transmural deposition of mature collagen in the blood vessels. We ruled out common causes of brain mineralization in humans and animals, but an etiology for the mineralization could not be determined. To our knowledge, mineralization in brain has been reported only once to occur in a chimpanzee, but its chronicity in our case makes it particularly interesting.Spontaneous vascular mineralization (deposition of iron or calcium salts) has been reported to occur in the brains of both humans and animals. This symptom has been observed in marble brain syndrome, mineralizing microangiopathy, hypothyroidism, Fahr syndrome, Sturge–Weber syndrome, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, and calciphylaxis in humans1,2,3,4 and as an aging or idiopathic lesion in the brains of horses, cats, nonhuman primates, mice, rats, cattle, white-tailed deer and dogs.5,6,7, 8-11 Vessels of the internal capsule, globus pallidus, cerebellar dentate nucleus, and infrequently, hippocampus are affected preferentially in horses, cattle, and, less commonly, dogs.7 Meningeal vessels in old cats, old horses, and cattle as well as vessels in the choroid plexus of old cats are other sites of vascular mineralization, but obvious ischemic damage is rarely associated with mineralization as a primary lesion in any animal species.7 Here we present a chimpanzee (Pan troglodytes) with extensive vascular mineralization that was localized solely to the brain.  相似文献   

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In this study, we cultivated from subsurface sediments an anaerobic clostridial consortium that was composed of a fermentative Fe-reducer Clostridium species (designated as strain FGH) and a novel sulfate-reducing bacterium belonging to the clostridia family Vellionellaceae (designated as strain RU4). In pure culture, Clostridium sp. strain FGH mediated the reductive dissolution/transformation of iron oxides during growth on peptone. When Clostridium sp. FGH was grown with strain RU4 on peptone, the rates of iron oxide reduction were significantly higher. Iron reduction by the consortium was mediated by multiple mechanisms, including biotic reduction by Clostridium sp. FGH and biotic/abiotic reactions involving biogenic sulfide formed by strain RU4. The Clostridium sp. FGH produced hydrogen during fermentation, and the presence of hydrogen inhibited growth and iron reduction activity. The sulfate-reducing partner strain RU4 was stimulated by the presence of H2and generated reactive sulfide which promoted the chemical reduction of the iron oxides. Characterization of Fe(II) mineral products showed the formation of nanoparticulate magnetite during ferrihydrite reduction, and the precipitation of iron sulfides during goethite and hematite reduction. The results suggest an important pathway for iron reduction and secondary mineralization by fermentative sulfate-reducing microbial consortia through syntrophy-driven biotic/abiotic reactions with biogenic sulfide.

Supplemental materials are available for this article. Go to the publisher's online edition of Geomicrobiology Journal to view the supplemental file.  相似文献   


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A bacterial strain, PNS-1, isolated from activated sludge, could utilize sulphanilic acid (4-ABS) as the sole organic carbon and energy source under aerobic conditions. Determination and comparison of 16S r DNA sequences showed that the strain PNS-1 is closely related to the species of Agrobacterium genus. Growth on 4-ABS was accompanied with ammonia and sulfate release. TOC results showed complete mineralization of sulphanilic acid. This strain was highly specific for 4-ABS as none of the sulphonated aromatics used in the present study including other ABS isomers were utilized. Strain PNS-1 could, however, utilize all the tested monocyclic aromatic compounds devoid of a sulfonate group. No intermediates could be detected either in the growth phase or with dense cell suspensions. Presence of chloramphenicol completely inhibited 4-ABS degradation by cells pregrown on succinate, indicating that degradation enzymes are inducible. No plasmid could be detected in the Agrobacterium sp. Strain PNS-1 suggesting that 4-ABS degradative genes may be chromosomal encoded.  相似文献   

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Four bacterial strains that use picric acid as their sole carbon and energy source were isolated. Mineralization of14C-UL-picric acid showed that up to 65% of the radioactivity was released as14CO2. HPLC and UV/Vis spectral analyses indicated complete degradation of picric acid by these organisms. HPLC and LC/MS analyses showed transient formation of 2,4-dinitrophenol during picric acid degradation. Degradation of picric acid was concomitant with stoichiometric release of three moles of nitrite per mole of picric acid. The four picric acid degraders were identified as close relatives ofNocardioides simplex (ATCC 6946) based on their small subunit (16S) rRNA gene sequences.This is contribution 7167 from Central Research & Development, Dupont Co, Wilmington, DE 19880, USA  相似文献   

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Xia Y  Gu Y  Zhou X  Xu H  Zhao X  Yaseen M  Lu JR 《Biomacromolecules》2012,13(8):2299-2308
Two types of thermoresponsive microgels, poly(N-isopropylacrylamide) (PNIPAM) microgels and poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAMAC) microgels were synthesized and used as templates for the mineralization of amorphous calcium carbonate (ACC) by diffusion of CO(2) vapor under ambient conditions. Thermosensitive PNIPAM/CaCO(3) hybrid macroscopic hydrogels and micrometer-sized PNIPAMAC/CaCO(3) hybrid microgels were controllably obtained and different mineralization mechanistic processes were proposed. The impact of the loaded CaCO(3) on the size, morphology, stability, and thermosensitivity of the microgels was also analyzed. PNIPAM/CaCO(3) hybrid macrogels had a slight decrease in thermoresponsive phase transition temperature, while PNIPAMAC/CaCO(3) hybrid microgels showed a clear increase in phase transition temperature. The difference reflected different amount and location of ACC in the gel network, causing different interactions with polymer chains. The PNIPAMAC/CaCO(3) microgels formed stable monolayer films on bare silica wafers and glass coverslips upon drying. The microgel films could facilitate the attachment and growth of 3T3 fibroblast cells and their subsequent detachment upon temperature drop from 37 °C to the ambient condition around 20 °C, thus, offering a convenient procedure for cell harvesting.  相似文献   

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The present study was carried out to determine the effect of probiotic, Bacillus subtilis, on ash and calcium contents of tibia bone in unchallenged and challenged broiler chicks with Salmonella enteritidis. In a completely randomized design, 160 chicks were divided into four groups. Each group had four replicates with 10 birds each. Treatments were control group, probiotic-treated group, challenged group and challenged probiotic-treated group. Ash and calcium contents of tibia at 21 and 42 days of age were determined. At 21 days of age, the highest contents of ash and calcium were related to probiotic-treated group and the lowest means to challenged chicks (P < 0.05). At this period, inclusion of probiotic to diet of challenged chick increased (P < 0.05) ash and calcium contents of tibia. With increases in age, the negative effects of challenging and beneficial effects of probiotic on bone mineralization diminished; since at 42 days of age, challenging or probiotic treatment had no effect on ash and calcium contents of tibia.  相似文献   

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U. Kierdorf      J. Becher 《Journal of Zoology》1997,241(1):135-143
The degree of dental wear was measured in 41 mandibular first molars from red deer of known age (range 2–18 years). The calculated wear indices were positively correlated with age ( r = 0.780, P < 0.001). In the same sample, significant ( P < 0.001) differences in hardness (determined by microhardness testing) were observed between enamel and coronal dentine as well as between outer and inner enamel and dentine, respectively. In animals belonging to the same age group (three-year-olds, n = 11), a negative correlation ( r = -0.830, P = 0.0016) was found between wear index and maximum mean enamel hardness. In a sample of five specimens from this age group, a negative correlation ( r = -0.918, P = 0.028) between maximum calcium concentration of enamel (measured by electron microprobing) and wear index was also recorded. We concluded that the intensity of enamel mineralization had a decisive effect on the degree of dental wear. Measuring of enamel hardness and subsequent modification of wear scores or indices is therefore recommended for future studies on the relationship between age and the degree of dental attrition in deer.  相似文献   

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Decalcified and undecalcified preparations of the crab Cancer pagurus in the intermoult condition were studied to examine the mineralization and structure of the epicuticle, using light microscopic, electron microscopic, and microradiographic methods. The epicuticle was found to be composed of two layers, one superficial membrane, and one thicker layer, measuring 1-2 μm. From the base layer spines or microtrichia projected. These were approximately 18 μm long and built like the remainder of the epicuticle. The spines and the base layer of the epicuticle contained vertical canals which in undecalcified sections accomodated columns of crystals. These canals were the only location in which minerals occurred in the epicuticle. In decalcified preparations filamentous strands were observed in the canals. Elsewhere in the epicuticular tissue no fibrillar structure was observed. The canals and their contents seemed to extend across the junctional zone between the epicuticle and the exocuticle.  相似文献   

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The upper cortex and extracellular hyphal wall matrix are mineralized in both rust-coloured Acarospora sinopica and the paler A. smaragdula ‘f. subochracea’ in the form of microgranular or microbotryoidal phases. Analysis confirmed the distinctive colours are not simply due to hydrated iron oxides, as previously believed, and suggests mixed sulphide and oxide phases with little crystallinity, as well as other elements arising from clay minerals are present. These aspects highlight the need for a more detailed study employing a range of micro-analytical techniques, including analytical TEM, which will allow mineral characterisation and localisation down to the nanometre scale.  相似文献   

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The exocuticle of the dorsal carapace of the intermoult Cancer pagurus was studied by means of light microscopy, electron microscopy, and contact microradiography. In the exocuticle a 5-15 μm wide highly mineralized external zone was seen where prisms were not present. The cross-sectional shape and diameter of the prisms varied. The prisms were separated by interprismatic areas varying in width and in degree of mineralization. With increasing width of the interprismatic areas the diameter of the prisms decreased. The prism-less external zone may be the result of complete mineralization of the prisms. The pore canals of the exocuticle were circular in cross section and present both within the prisms and within the interprismatic areas. The lamellar system of the exocuticle was built up by layers of horizontal fibrils which were interconnected by vertical or oblique fibrils. The minerals of the external prism-less zone occurred as aggregates of crystalline matter or as large brick-like structures. Crystal edge lengths up to 300 nm were measured. In well mineralized interprismatic areas aggregates of crystals and relatively large crystals were observed. In poorly mineralized interprismatic areas small plate-like crystals occurred. Occasionally a prism-less zone was seen near the exocuticle/endocuticle junction.  相似文献   

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The degradability of pivalic acid was established by the isolation of several facultative denitrifying strains belonging to Zoogloea resiniphila, to Thauera and Herbaspirillum, and to Comamonadaceae, related to [Aquaspirillum] and Acidovorax, and of a nitrate-reducing bacterium affiliated with Moraxella osloensis. Pivalic acid was completely mineralized to carbon dioxide. The catabolic pathways may involve an oxidation to dimethylmalonate or a carbon skeleton rearrangement, a putative 2,2-dimethylpropionyl coenzyme A mutase.  相似文献   

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铀的生物成矿作用及成矿过程中矿质元素循环   总被引:1,自引:0,他引:1  
概述了微生物成矿作用,并介绍了硫杆菌、硫酸盐还原菌、铁细菌、硝化细菌、反硝化细菌等各种细菌在与铀的生物成矿过程相关的地质元素循环中所起到的作用。并展望了今后矿床中微生物种群的研究方向。  相似文献   

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Lees S 《Biophysical journal》2003,85(1):204-207
It was previously found that the lateral spacing of the collagen molecules in wet mineralized tissues is exactly proportional to the inverse wet density. Several properties were investigated and the same type of relationship was observed each time. A possible explanation is offered. It is hypothesized that mineral is deposited initially in the extrafibrillar space so as to isolate the fibrils. Further deposition reduces the net free fibril volume thereby decreasing the spacing between collagen molecules. The linear relationship is derived from density considerations together with limitations on the collagen packing structure described as the generalized packing model. Three experimental situations were studied: lateral spacing wet tissue versus density; lateral spacing dry tissue versus density; and lateral spacing versus water content. The observed variations of the spacing can be attributed to a structure where the mass of the tissue remains constant but the volume decreases linearly with increasing mineral content.  相似文献   

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