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991.
992.
993.
Sexuality in fungi has long been a matter of concerns and debates that always necessitated extensive analysis of the relationship between organisms assumed to represent different developmental forms of the same organism. Moreover, mating-virulence correlation and the growing worry of opportunistic fungal infections in immunocompromised states associated with AIDS, cancer chemotherapy and organ transplantation protocols have been critically addressed nowadays. In view of that, we genetically characterized Aspergillus chevalieri, Aspergillus nidulans, Aspergillus tetrazonus (quadrilineatus) and their teleomorphs with RAPD analysis using 5'-d[AACGCGCAAC]-3' and 5'-d[CCCGTCAGCA]-3' primers. The reported similarities between the sexual and the asexual forms of the tested species, using Dice coefficient, ranged between 40% and 70% which holds pretty much with the current systematics of the genus. The study presents a rapid consistent method for identification of A. chevalieri, A. nidulans, A. tetrazonus (quadrilineatus) and their teleomorphs based on the banding pattern of RAPD-generated fragments that can be reliably used ahead of further applications on these species. 相似文献
994.
We describe the ultrastructural organization of the vitellogenic follicle stages in two caecilian species. Monthly samples
of slices of ovary of Ichthyophis tricolor and Gegeneophis ramaswamii from the Western Ghats of India were subjected to transmission electron-microscopic analysis, with special attention to the
follicle cell/oocyte interface. In order to maintain uniformity of the stages among the amphibians, all the stages in the
caecilian follicles were assigned to stages I–VI, the vitellogenic and post-vitellogenic follicles being assigned to stages
III–VI. Stage III commences with the appearance of precursors of vitelline envelope material in the perivitelline space. Stages
IV and V have been assigned appropriate substages. During the transition of stage III to stage VI oocytes, a sequential change
occurs in the manifestations of follicle cells, perivitelline space, vitelline envelope and oocyte cortex. The vitelline envelope
becomes a tough coat through the tunnels of which the macrovilli pass to interdigitate between the microvilli. The oocyte
surface forms pinocytic vesicles that develop into coated pits and, later, coated vesicles. Contributions of the oocyte cortex
to the vitelline envelope and of the follicle cells to yolk material via synthesis within them are indicated. The follicle
cell/oocyte interface of vitellogenic follicles of these two caecilians resembles that in anurans and urodeles, with certain
features being unique to caecilians. Thus, this paper throws light on the possible relationships of caecilians to anurans
and urodeles with special reference to ovarian follicles.
This research was supported by funds from the Kerala State Council for Science, Technology and Environment (KSCSTE), through
the SARD facility, and by the FIST scheme of Department of Science and Technology, Government of India, New Delhi, to the
Department of Zoology, University of Kerala, Thiruvananthapuram, and to the Department of Animal Science, Bharathidasan University,
Thiruchirapalli (SR/FST/LSI-233/2002). 相似文献
995.
Bocian W Sitkowski J Bednarek E Tarnowska A Kawecki R Kozerski L 《Journal of biomolecular NMR》2008,40(1):55-64
Here we present evidence that in water/acetonitrile solvent detailed structural and dynamic information can be obtained for
important proteins that are naturally present as oligomers under native conditions. An NMR-derived human insulin monomer structure
in H2O/CD3CN, 65/35 vol%, pH 3.6 is presented and compared with the available X-ray structure of a monomer that forms part of a hexamer
(Acta Crystallogr. 2003 Sec. D59, 474) and with NMR structures in water and organic cosolvent. Detailed analysis using PFGSE
NMR, temperature-dependent NMR, dilution experiments and CSI proves that the structure is monomeric in the concentration and
temperature ranges 0.1–3 mM and 10–30°C, respectively. The presence of long-range interstrand NOEs, as found in the crystal
structure of the monomer, provides the evidence for conservation of the tertiary structure. Starting from structures calculated
by the program CYANA, two different molecular dynamics simulated annealing refinement protocols were applied, either using
the program AMBER in vacuum (AMBER_VC), or including a generalized Born solvent model (AMBER_GB).
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Wojciech Bocian contributed equally to this work. 相似文献
996.
El Idrissi A 《Amino acids》2008,34(2):321-328
Summary. We have determined the role of mitochondria in the sequestration of calcium after stimulation of cerebellar granule cells
with glutamate. In addition we have evaluated the neuroprotective role of taurine in excitotoxic cell death. Mitochondrial
inhibitors were used to determine the calcium buffering capacity of mitochondria, as well as how taurine regulates the ability
of mitochondria to buffer intracellular calcium during glutamate depolarization and excitotoxicity. We report here that pre-treatment
of cerebellar granule cells with taurine (1 mM, 24 h) significantly counteracted glutamate excitotoxicity. The neuroprotective
role of taurine was mediated through regulation of cytoplasmic free calcium ([Ca2+]
i
), and intra-mitochondrial calcium homeostasis, as determined by fluo-3 and 45Ca2+-uptake. Furthermore, the overall mitochondrial function was increased in the presence of taurine, as assessed by rhodamine
accumulation into mitochondria and total cellular ATP levels. We specifically tested the hypothesis that taurine reduces glutamate
excitotoxicity through both the enhancement of mitochondrial function and the regulation of intracellular (cytoplasmic and
intra-mitochondrial) calcium homeostasis. The role of taurine in modulating mitochondrial calcium homeostasis could be of
particular importance under pathological conditions that are characterized by excessive calcium overloads. Taurine may serve
as an endogenous neuroprotective molecule against brain insults.
Authors’ address: Abdeslem El Idrissi, Biology Department and Center for Developmental Neuroscience, College of Staten Island/CUNY,
6S-134 Staten Island, NY 10314, U.S.A. 相似文献
997.
998.
999.
Martin Shapiro Said El Salamouny B. Merle Shepard 《Biocontrol Science and Technology》2008,18(6):591-603
The addition of a caffeinated green tea, Camellia sinensis L., filtrate (1%) to the nucleopolyhedrovirus (SeMNPV) of the beet armyworm, Spodoptera exigua (Hübner), provided almost complete protection following UVB irradiation (30 min) in laboratory tests. There were few differences in UV protection when extracts were prepared at 27 or at 90°C. Moreover, few differences in UV protection were demonstrated following infusion times of 5, 15, 30, and 60 min at 90°C. At a 1% concentration, decaffeinated and caffeinated green teas were equally effective as UV protectants. At lower concentrations (0.1, 0.01, and 0.001%) caffeinated green tea provided greater UV protection (UVB/UVB 30, 60 min). Virus/tea extracts (caffeinated), under field conditions at 1 and 5%, were ineffective as UV screens. At a 10% concentration, some UV protection was provided and UV protection further increased in a concentration-dependent manner. 相似文献
1000.
Decolorization of Fast red by metabolizing cells of <Emphasis Type="Italic">Oenococcus oeni</Emphasis> ML34 总被引:1,自引:1,他引:0
Amani M. D. El Ahwany 《World journal of microbiology & biotechnology》2008,24(8):1521-1527
Three different azo dyes such as Fast red, metanil yellow and Fast orange were examined for their decolorization by O. oeni ML34. Fast red (FR) was decolorized by 68%, whereas the other dyes were removed by only about 30%. The effects of glucose
addition, substrate (dye) concentration and environmental factors (temperature, pH) on decolorization were investigated by
two-level factorial design. The statistical analyses revealed that glucose specifically increases the extent of FR decolorization.
A glucose level of 5 g/l was the optimum concentration for removal of, FR reaching a decolorization percentage of up to 93%. 相似文献