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Oussama El Far Béatrice Marquèze Christian Leveque Nicole Martin-Moutôt Bethan Lang John Newsom-Davis †Akira Yoshida †Masami Takahashi Michael J. Seagar 《Journal of neurochemistry》1995,64(4):1696-1702
Abstract: In Lambert-Eaton myasthenic syndrome neurotransmitter release is reduced by an autoimmune response directed against the calcium channel complex of the nerve terminal. Autoantibodies were detected by immunoprecipitation assays using solubilized receptors labeled with ligands selective for N-type (125 I-ω conotoxin GVIA) and L-type ([3 H]PN200-110) calcium channels. Sera with a high antibody titer (>3 n M ) against rat brain N-type channels contained autoantibodies that immunoprecipitated neuronal and muscle L-type channels. These IgG fractions stained a 55-kDa protein in immunoblots of purified skeletal muscle dihydropyridine receptor, suggesting that they contain autoantibodies against the β subunit of the calcium channel. A distinct antibody population in the same fractions reacted with a nerve terminal 65-kDa protein that is unrelated to the β subunit and displays properties similar to those of synaptotagmin. 相似文献
3.
Activity of salivary glands in secreting honey‐elaborating enzymes in two subspecies of honeybee (Apis mellifera L) 下载免费PDF全文
Aliaa A. Al‐Sherif Adel M. Mazeed Mohamed A. Ewis Emad A. Nafea El‐Seid E. Hagag Ahmed A. Kamel 《Physiological Entomology》2017,42(4):397-403
The activity of invertase, glucose oxidase and amylase in the cephalic (post‐cerebral) and thoracic salivary glands is determined in Egyptian and Carniolan honeybees (Apis mellifera L). For this purpose, three ages of worker bees are selected for enzyme assays. The results show that the three target enzymes are detected in the two glands during the three worker ages, except invertase, which cannot be detected in the cephalic gland of newly emerged bees of both subspecies. In both glands, the secretion of invertase is highest, followed by amylase and then glucose oxidase. In Carniolan bees, invertase secretion of the cephalic and thoracic glands increases gradually with age. In Egyptian bees, invertase increases with age only in the cephalic gland, whereas, in the thoracic gland, the highest secretion activity is detected in 10–15‐day‐old bees. The highest amounts of glucose oxidase and amylase in the cephalic gland are detected in newly emerged individuals of both Egyptian and Carniolan bees. In the thoracic gland, however, the highest activity of both enzymes is recorded only in newly emerged Egyptian bees. The results are discussed in the light of bee management and biological aspects of the two subspecies. 相似文献
4.
Mohamed M. Eid Samy I. El-Kowrany Ahmad A. Othman Dina I. El Gendy Eman M. Saied 《The Korean journal of parasitology》2015,53(1):51-58
Toxocariasis is a soil-transmitted helminthozoonosis due to infection of humans by larvae of Toxocara canis. The disease could produce cognitive and behavioral disturbances especially in children. Meanwhile, in our modern era, the incidence of immunosuppression has been progressively increasing due to increased incidence of malignancy as well as increased use of immunosuppressive agents. The present study aimed at comparing some of the pathological and immunological alterations in the brain of normal and immunosuppressed mice experimentally infected with T. canis. Therefore, 180 Swiss albino mice were divided into 4 groups including normal (control) group, immunocompetent T. canis-infected group, immunosuppressed group (control), and immunosuppressed infected group. Infected mice were subjected to larval counts in the brain, and the brains from all mice were assessed for histopathological changes, astrogliosis, and IL-5 mRNA expression levels in brain tissues. The results showed that under immunosuppression, there were significant increase in brain larval counts, significant enhancement of reactive gliosis, and significant reduction in IL-5 mRNA expression. All these changes were maximal in the chronic stage of infection. In conclusion, the immunopathological alterations in the brains of infected animals were progressive over time, and were exaggerated under the effect of immunosuppression as did the intensity of cerebral infection. 相似文献
5.
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The vegetables germplasm conservation programme in Poland was started in 1982, activities under this program resulted up to
this date in building up a tomato germplasm collection of 782 accessions that are available for distribution to breeders and
researchers in Poland and abroad. Between 1990 and 1999 we distributed 651 tomato seed samples to breeders and scientists
in Poland, and 95 samples to users abroad. During 1990 – 1999 the 652 tomato accessions were evaluated for 43 traits of plants
and fruits. Work is in progress to expand the collection and identify useful characteristics of the collected material, and
to make use of them in breeding and other research works. 相似文献
7.
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The estrogen of the doum palm kernel and pollen grains has been isolated as the p,p′-nitrophenylazo benzoyl derivative and identified as estrone. 相似文献
9.
In agricultural areas, Aspergillus
flavus, Aspergillus fumigatus and Aspergillus parasiticus are commonly identified in various feedstuffs and bioaerosols originated from feed handling. Some isolates belonging to these
fungal species could produce mycotoxins and constitute a risk factor for human and animal health. In this study, Fourier-transform
infrared spectroscopy was used for a rapid detection and characterization of 99 isolates collected from agricultural areas.
The results showed a first cluster corresponding to strains previously attributed to the A.
fumigatus group according to current taxonomic concepts, and a second cluster divided in 2 groups around reference strains of A.
flavus and A. parasiticus species. The toxigenic capacity of isolates was evaluated by high performance liquid chromatography coupled to mass spectrometry.
In the A. flavus group, only 6 strains of A. parasiticus and 4 strains of A. flavus were able to produce aflatoxins on culture media. FT-IR spectroscopy, respectively, allowed the differentiation of non-toxigenic
and toxigenic A. flavus and A. parasiticus isolates at 75 and 100%. Discrimination between toxigenic and non-toxigenic A. fumigatus was not possible because all of the isolates produced at least one mycotoxin. 相似文献
10.
Over 100 of Pseudomonas aeruginosa isolates representing the two TTSS genotypes (exoU
−/exoS
+ or exoU
+/exoS
−) were cultured in different media in order to evaluate their proteolytic activities and find a relationship between proteolytic
activity and the cytotoxic and/or invasive phenotypes displayed by the strains upon infection of RAW 264.7 murine macrophage-like
cells and pulmonary microvascular endothelial cells (PME). The elastolytic activity, protein concentration, and total proteolytic
activity (TPA) were measured in culture supernatants. No significant differences were observed in the median elastolytic activities
among cytotoxic/noninvasive, noncytotoxic/invasive, and cytotoxic/invasive phenotypes displayed by P. aeruginosa strains. The only significant difference was noted when isolates of the two different TTSS genotypes were grown in a calcium-depleted
minimal medium for induction of TTSS (MI). The exoU
−/exoS
+ isolates showed significant higher levels of the median elastolytic activity when compared to the exoU
+/exoS
− isolates. These two groups of isolates secreted the elastase B (LasB) with distinct molecular masses 158 or 116 kD, respectively.
The strains of the two TTSS genotypes secreted similar amount of total proteins; however, the higher values of TPA were observed
for the isolates of the exoU
+
/exoS
− genotype when grown in MI medium. We concluded that there is no direct relationship between secretion of proteases with elastolytic
activity and the cytotoxic and/or invasive phenotypes of the isolates observed upon infection of both RAW 264.7 and PME monolayers.
Further studies are needed to find out whether others factors beside proteases could influence the mechanism of host cells
intoxication mediated by the P. aeruginosa TTSS-delivered toxins. 相似文献