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A wide-ranging examination of plastid (pt)DNA sequence homologies within
higher plant nuclear genomes (promiscuous DNA) was undertaken. Digestion
with methylation-sensitive restriction enzymes and Southern analysis was
used to distinguish plastid and nuclear DNA in order to assess the extent
of variability of promiscuous sequences within and between plant species.
Some species, such as Gossypium hirsutum (cotton), Nicotiana tabacum
(tobacco), and Chenopodium quinoa, showed homogenity of these sequences,
while intraspecific sequence variation was observed among different
cultivars of Pisum sativum (pea), Hordeum vulgare (barley), and Triticum
aestivum (wheat). Hypervariability of plastid sequence homologies was
identified in the nuclear genomes of Spinacea oleracea (spinach) and Beta
vulgaris (beet), in which individual plants were shown to possess a unique
spectrum of nuclear sequences with ptDNA homology. This hypervariability
apparently extended to somatic variation in B. vulgaris. No sequences with
ptDNA homology were identified by this method in the nuclear genome of
Arabidopsis thaliana.
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A survey was conducted to determine the levels of fumonisins B1 and B2 in corn and corn-based products available in Colombia
for human and animal consumption. A total of 120 samples were analyzed by acetonitrile-water extraction, cleanup with a strong-anion-exchange
column, and liquid chromatography with o-phthaldialdehyde-2-mercaptoethanol derivatization and fluorescence detection. The
samples of corn and corn-based products for animal intake were taken at different feed manufacturing plants, whereas the samples
used for human foods where purchased from local retail stores. The number of positive samples for fumonisin B1 was 20.0% higher
in corn and corn-based products for animal intake (75.0%) than in corn and corn-based products for human consumption (55.0%).
The levels of fumonisin B1 were also higher in corn and corn-based products for animal intake (mean = 694 μg/kg; range = 32–2964
μg/kg), than in corn and corn-based products for human intake (mean = 218 μg/kg; range = 24–2170 μg/ kg). The incidence and
levels of fumonisin B2 were lower than those for fumonisin B1. Corn and corn-based products for animal consumption had an
incidence of fumonisin B2 of 58.3%, with a mean value of 283 μg/kg, and a range of 44–987 μg/kg. The incidence of fumonisin
B2 in corn-based products for human intake was 35.0%, with a mean value of 118 μg/kg and a range of 21–833 μg/kg. The highest
incidence and levels of fumonisins were found in samples of hominy feed, with concentrations ranging from 86 to 2964 μg/kg
fumonisin B1 and 57 to 987 μg/kg fumonisin B2. 相似文献
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ERVĪNS LUKŠEVIČS PER E. AHLBERG ĢIRTS STINKULIS JEĻENA VASIĻKOVA IVARS ZUPIŅŠ 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2012,45(3):356-370
Luk?evi?s, E., Ahlberg, P.E., Stinkulis, ?., Vasi?kova, J. & Zupi??, I. 2011: Frasnian vertebrate taphonomy and sedimentology of macrofossil concentrations from the Langsēde Cliff, Latvia. Lethaia, Vol. 45, pp. 356–370. The siliciclastic sequence of the Upper Devonian of Kurzeme, Western Latvia, is renowned for abundant vertebrate fossils, including the stem tetrapods Obruchevichthys gracilis and Ventastega curonica. During the first detailed taphonomic study of the vertebrate assemblage from the Ogre Formation cropping out at the Langsēde Cliff, Imula River, abundant vertebrate remains have been examined and identified as belonging to one psammosteid, two acanthodian and three sarcopterygian genera; the placoderm Bothriolepis maxima dominates the assemblage. Besides fully disarticulated placoderm and psammosteid plates, separate sarcopterygian scales and teeth, and acanthodian spines, partly articulated specimens including complete distal segments of Bothriolepis pectoral fins, Bothriolepis head shields and sarcopterygian lower jaws have been found. The size distribution of the placoderm bones demonstrates that the individuals within the assemblage are of approximately uniform age. Distinct zones have been traced within the horizontal distribution of the bones. These linear zones are almost perpendicular to the dominant dip azimuth of the cross‐beds and ripple‐laminae and most probably correspond to the depressions between subaqueous dunes. Concavity ratio varies significantly within the excavation area. The degree of fragmentation of the bones and disarticulation of the skeletons suggest that the carcasses were reworked and slightly transported before burial. Sedimentological data suggest deposition in a shallow marine environment under the influence of rapid currents. The fossiliferous bed consists of a basal bone conglomerate covered by a cross‐stratified sandstone with mud drapes, which is in turn overlain by ripple laminated sandstone, indicating the bones were buried by the gradual infilling of a tidal channel. All the Middle–Upper Devonian vertebrate bone‐beds from Latvia are associated with sandy to clayey deposits and have been formed in a sea‐coastal zone during rapid sedimentation episodes, but differ in fossil abundance and degree of preservation. □Agnathans, Devonian, facies analysis, fish, fossil assemblage, palaeoenvironment. 相似文献
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Dessardo NS Dessardo S Sasso A Sarunić AV Dezulović MS 《Collegium antropologicum》2010,34(Z2):217-221
Idiopathic intracranial hypertension (IIH) is a clinical condition characterized by elevated intracranial pressure and absence of clinical, laboratory or radiographic evidence of central nervous system infection, vascular malformation, intracranial space occupying lesion or hydrocephalus. In the last years the raising understanding of pediatric IIH, especially concerning its demographics and epidemiology, has brought up to a redefinition of diagnostic criteria and reevaluation of pathogenesis and treatment. The authors reviewed the records of nineteen consecutive children with newly diagnosed IIH in order to compare demographic characteristics, clinical pictures and ophthalmologic aspects as optic disc evaluation and visual field evaluation, as well as treatment modalities and follow up. Beside obesity and female gender, potential alternative risk factors remains to be investigated, which need a good collaboration between neuro-ophthalmologists and pediatric neurologists. 相似文献
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Subat-Dezulović M Dessardo NS Dezulović M Dessardo S Hadzisejdić I Brncic N 《Collegium antropologicum》2010,34(Z2):229-232
Contrary to group A beta-hemolytic streptococcus as the most common cause of postinfectious glomerulonephritis (PIGN), Epstein-Barr virus (EBV) is only occasionally associated with acute renal involvement. We describe an 11-year-old boy who presented with clinical signs of infective mononucleosis and acute glomerulonephritis characterized by edema, hypertension and dark colored urine with diminished renal function. Serology tests confirmed streptococcal infection and acute EBV infection. Persistently depressed C3 complement and gross hematuria indicated renal biopsy which shows PIGN-type picture and, in addition, acute interstitial nephritis, both conclusive of streptococcal infection. We performed tissue DNA extraction by polymerase chain reaction (PCR) and demonstrated EBV-DNA from the kidney specimen supporting EBV involvement in renal tissue. This is the first reported case of PIGN with serologically-proven streptococcal and simultaneously, acute EBV co-infection. EBV-DNA extraction supported the EBV involvement in renal tissue suggesting that both etiologic agents might have contributed to renal inflammation. Adding serology evaluation for EBV in cases with typical clinical signs of infective mononucleosis and renal symptoms, EBV might be more commonly associated with PIGN than is currently appreciated. 相似文献
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Thomas G Kristensen Jesper Nielsen Christian NS Pedersen 《Algorithms for molecular biology : AMB》2010,5(1):9
Background
The fingerprint of a molecule is a bitstring based on its structure, constructed such that structurally similar molecules will have similar fingerprints. Molecular fingerprints can be used in an initial phase of drug development for identifying novel drug candidates by screening large databases for molecules with fingerprints similar to a query fingerprint. 相似文献10.
Thomas Mailund Gerth S Brodal Rolf Fagerberg Christian NS Pedersen Derek Phillips 《BMC bioinformatics》2006,7(1):29-8