PSP94融合蛋白在大肠杆菌中的表达及其抗前列腺癌活性分析

在从成年人正常前列腺组织中获得人９４个氨基酸的前列腺分泌蛋白（ＰＳＰ９４）ｃＤＮＡ基础上,利用ＰＬ表达系统,实现了人ＰＳＰ９４成熟肽Ｎ 末端带有１９个外源氨基酸的融合蛋白在大肠杆菌中的表达。目的蛋白在细胞中主要以包涵体形式存在,表达量约占菌体总蛋白的３０％,分子量约为１６－５ｋＤ。表达产物在人前列腺癌细胞ＰＣ ３上活性分析表明,该融合蛋白能明显抑制前列腺癌细胞的生长。     

Impact of elevated atmospheric CO2 and O3 on gas exchange and chlorophyll content in spring wheat (Triticum aestivum L.)

Stands of spring wheat grown in open-top chambers (OTCs) wereused to assess the individual and interactive effects of season-longexposure to elevated atmospheric carbon dioxide (CO₂ and ozone(O₃) on the photosynthetic and gas exchange properties of leavesof differing age and position within the canopy. The observedeffects were related to estimated ozone fluxes to individualleaves. Foliar chlorophyll content was unaffected by elevatedCO₂ but photosynthesis under saturating irradiances was increasedby up to 100% at 680 µmol mol^–1 CO₂ relative tothe ambient CO₂ control; instantaneous water use efficiencywas improved by a combination of increased photosynthesis andreduced transpiration. Exposure to a seasonal mean O₃ concentration(7 h d^–1) of 84 nmol mol^–1 under ambient CO₂ acceleratedleaf senescence following full expansion, at which time chlorophyllcontent was unaffected. Stomatal regulation of pollutant uptakewas limited since estimated O₃ fluxes to individual leaves werenot reduced by elevated atmospheric CO₂, A common feature ofO₃-treated leaves under ambient CO₂ was an initial stimulationof photosynthesis and stomatal conductance for up to 4 d and10 d, respectively, after full leaf expansion, but thereafterboth variables declined rapidly. The O₃-induced decline in chlorophyllcontent was less rapid under elevated CO₂ and photosynthesiswas increased relative to the ambient CO₂ treatment. A/C_i analysessuggested that an increase in the amount of in vivo active RuBisCOmay be involved in mitigating O₃-induced damage to leaves. Theresults obtained suggest that elevated atmospheric CO₂ has animportant role in restricting the damaging effects of O₃ onphotosynthetic activity during the vegetative growth of springwheat, and that additional direct effects on reproductive developmentwere responsible for the substantial reductions in grain yieldobtained at final harvest, against which elevated CO₂ providedlittle or no protection. Key words: Elevated CO₂ and O₃, gas exchange, O₃ flux, stomata, chlorophyll, Triticum aestivum     

Aspergillus terreus and its toxic metabolites as a food contaminant in some Egyptian Bakery products and grains

A. terreus isolates isolated from some bakery products, corn and rice were found to be able to produce territrems. 90% of theA. terreus isolated from bakery products were able to produce territrem A, with a mean of 0.09 ppm, while 80% ofA. terreus isolates produce territrem B with a mean of 0.24 ppm. On the other hand 31.8% of the isolates ofA. terreus from corn were able to produce territrem A with a mean of 0.44 ppm. ConcerningA. terreus isolates from rice, 66.7% were found to produce territrem A, with a mean of 5.28 ppm, and 77.8% of the isolates produced territrem B with a mean of 1.79 ppm.     

Impact of elevated CO(2) and O(3) on gas exchange parameters and epidermal characteristics in potato (Solanum tuberosum L.)

Potato plants (Solanum tuberosum L. cv. Bintje) were grown in open-top chambers (OTCs) under three CO(2) levels (ambient and 24 h d(-1) seasonal mean concentrations of 550 and 680 micromol mol(-1)) and two O(3) levels (ambient and a seasonal mean 8 h d(-1) concentration of 50 nmol mol(-1)). The objectives were to determine the effects of season-long exposure to these key climate change gases on gas exchange, leaf thickness and epidermal characteristics. The experimental design also provided an ideal opportunity to examine within-leaf variation in epidermal characteristics at the whole-leaf level. Stomatal and epidermal cell density and stomatal index were measured at specific locations on the youngest fully expanded leaf (centre of lamina, mid-way between tip and base) and representative whole leaves from each treatment. Effects on leaf conductance, assimilation rate and instantaneous transpiration efficiency were determined by infrared gas analysis, while anatomical characteristics were examined using a combination of leaf impressions and thin sections. Exposure to elevated CO(2) or O(3) generally increased leaf thickness, leaf area, stomatal density, and assimilation rate, but reduced leaf conductance. The irregular stomatal distribution within leaves resulted from a combination of uneven differentiation and expansion of the epidermal cells. The results are discussed with reference to sampling protocols and the need to account for within-leaf variation when examining the impact of climate change or other environmental factors on epidermal characteristics.     

Vasospasm is a significant factor in cyclosporine-induced neurotoxicity: Case report

Background

The aetiology of central nervous system lesions observed in cerebral cyclosporine neurotoxicity remains controversial.

Case presentation

We report a 48-year-old woman with a non-severe aplastic anaemia who presented with stroke-like episodes while on cyclosporine treatment.Transcranial Doppler ultrasound revealed severely elevated flow velocities in several cerebral vessels, consistent with vasospasm. Immediately after reducing the cyclosporine dose, the stroke-like episodes disappeared. Only after cyclosporine withdrawal the transcranial Doppler ultrasound abnormalities fully resolved.

Conclusions

This case demonstrates a significant role of vasospasm in the pathway of cyclosporine-induced neurotoxicity. Transcranial Doppler ultrasound is an effective tool for the diagnosis and follow-up of cyclosporine-induced vasospasm.

     

Sources of fish in the ephemeral western iishana region of the Cuvelai–Etosha Basin in Angola and Namibia

The triangle between the Kavango and Kunene rivers is drained by the Cuvelai, an ephemeral and deltaic drainage system covering more than 100 000 km². In good rainfall years, the area becomes populated by fish communities dominated by five species migrating southward towards the endorheic Etosha Pan, the basin’s terminal sump. When water dries up, fish subsequently die-off and their sudden appearance in rainy years has captivated scientists for decades. The current study was prompted by hitherto untapped indigenous knowledge through narratives of opportunistic fish harvesting of migrating fish at temporary connections between the Kunene River and the Cuvelai- Etosha Basin. A reconnaissance fish survey in 2017 was complemented by digital satellite images and elevation data analyses. Results support the presence of at least three major ephemeral fish migration routes. The dominant fish genera migrating upstream in Kunene tributaries comprise Enteromius, Oreochromis and Clarias, all eurytopic and known to undertake upstream, lateral and downstream migrations on floodplains. Although other notable fish refugia in the Cuvelai–Etosha Basin are yet to be identified, there is a necessity for the protection and management of these migration routes in tandem with studies on the nature and extent of this inter-basin fish migration under climate change and variability.     

The molecular organization of the beta-globin complex of the deer mouse, Peromyscus maniculatus

Recombinant DNA clones have been isolated that contain 80 kb of the beta-globin complex from the deer mouse, Peromyscus maniculatus. Comparisons of this complex with that from the laboratory mouse, Mus domesticus (with an order 5'-Hbby, Hbb-bhO, Hbb-bhl, Hbb-bh2, Hbb-bh3, Hbb-bl, Hbb-b2 3') highlight organizational trends in the beta-globin complex since the two species diverged. Unlike other mammals studied thus far, the deer mouse possesses three adult genes. Partial sequence analysis indicates that each of the three adult genes is intact and hence may be functional. Hybridization of one of the two Mus pseudogenes, Hbb-bh3, to genomic blots from Peromyscus reveals that it has a homologous counterpart in Peromyscus. Homologous genes to the two gamma-like Mus genes, Hbb-bhO and Hbb-bhl, are also found in Peromyscus. The strong hybridization between the Hbb-bhl genes and significant nucleotide similarity between the Hbb-bhO genes suggest that both pairs are important for the ontogeny of these mice although no known product has been identified for the Hbb-bhO genes. The presence of Hbb-bhO and Hbb-bhl in Peromyscus suggests that the duplication that created this related gene set occurred before the two lineages diverged. A single gene for Hbb-y has been isolated from Peromyscus. The adult region in Peromyscus has undergone significant divergence from the same region in Mus, having three rather than two adult genes, the acquisition of at least 15 kb of extra DNA relative to Mus, and possibly the loss of the Hbb-bh2 pseudogene. The nonadult region of the complex, in contrast, contains the same set of genes apparently distributed over the same amount of DNA as in the Mus beta- globin complex. This observation suggests that the embryonic region of the complex is more evolutionarily stable than the adult region.