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排序方式: 共有235条查询结果,搜索用时 10 毫秒
1.
Summary The presence of house dust mites and storage mites in dumpsters was investigated in 3 different areas of Venice hinterland. The aim of this study was to find a relationship between some reported respiratory symptoms among 6 workers who were responsible for moving the dumpsters to the truck and the bio-aerosol released from such operation. These symptoms were closely related to the work and after allergological evaluation we found sensitisation to house dust mites in all 6 employees. The mine exposure in the workplace was assessed by a standardized sampling and analysis of dust obtained after brushing the inside surfaces of dumpsters. In 50% of the specimens (10/20) we found mites belonging to the following families: Pyroglyphidae (Dermatophagoides spp.), Acaridae (Acarus siro) and a lower amount of Cheyletidae (Cheyletus spp.). An indirect test (guanine test) was also performed and gave positivity in 16 dust samples (80%). The insides of dumpsters showed to be an optimal environment for mites survival and reproduction because of cracks and grooves on the walls, the high humidity level and the presence of mould. These mites probably come from dwelling places and other environments (markets, slaughters-houses, farms, etc.). This suggests that mites allergens can be released during rubbish discharging from the dumpsters and represent a possible risk for the employees. 相似文献
2.
Summary In order to evaluate the frequency of skin sensitivity to Storage Mites and the role of such sensitization in respiratory allergic disease in workers with occupational exposure to stored items we studied 217 dock workers, 93 farmers and 104 white collars.From the results of skin prick tests the sensitization to sole Storage Mites appears significantly higher among people working in docks or farms, compared with a control group. This confirms the role of the working environment in inducing sensitization to Storage Mites. Rhinitis and asthma however affect nearly always (27/29 cases) people with an associated sensitization to House Dust Mites. Further studies are needed to define the allergenic importance of Storage Mites in working environments. 相似文献
3.
TMA-DPH fluorescence decay in human PMN before and after stimulation with FMLP was studied using frequency domain fluorometry. Membrane heterogeneity was assessed by the width of the continuous distributions of lifetime values of Lorentzian shape used to describe the fluorescence decay. In non-stimulated granulocytes TMA-DPH fluorescence decay is characterized by two distributions of lifetime values centered at 6.5 and 1.0 ns and full width at half maximum of 0.3 and 1.2 ns, respectively. Within 15 min after stimulation, the center values of the two distribution components were 5.1 and 0.8 ns and the distribution width was 0.8 and 0.6 ns, respectively. These results indicate changes of membrane domain organization which can be ascribed to compositional changes and redistribution of membrane components. 相似文献
4.
M Valentino R Arcaleni I Visonà M Governa 《Bollettino della Società italiana di biologia sperimentale》1985,61(1):145-149
The PMNs of fourteen patients undergoing general anesthesia for surgical operations were examined to determine whether abnormal chemotaxis occurs during these procedures. Neutrophil chemotaxis was determined immediately before anesthesia and after the anesthetic somministration. Anesthetic agents included 0.2-1% enflurane, 0.3-1% halothane or N20-02 (60:40). Neutrophil chemotaxis was reduced an average of 10.9% by fluorinated anesthetics, no significant modification (+8.1 +/- 13.0%) was detected by N20-02. 相似文献
5.
Cytokeratin expression in simple epithelia 总被引:10,自引:0,他引:10
Valentino Romano Mechthild Hatzfeld Thomas M. Magin Ralf Zimbelmann Werner W. Franke Gernot Maier Herwig Ponstingl 《Differentiation; research in biological diversity》1986,30(3):244-253
To study the regulation of the expression of cytokeratins characteristic of simple epithelia, i.e., human cytokeratins nos. 7, 8, 18, and 19, we prepared several cDNA clones coding for these proteins and their bovine counterparts. In the present study, we describe a cDNA clone of the mRNA coding for human cytokeratin no. 18, which was isolated from an expression library using the monoclonal antibody, KG 8.13. This clone (756 nucleotides, excluding the polyA portion), encodes approximately one-half of the mRNA (approximately 1.4 kb), identifies one mRNA band in Northern-hybridization blots, and specifically selects one mRNA species coding for cytokeratin no. 18, as demonstrated by translation in vitro. Comparison of the deduced amino acid sequence--confirmed by direct amino-acid-sequence analyses of some polypeptide fragments produced by cleavage with cyanogen bromide--indicated that cytokeratin no. 18 is a member of the acidic (type I) subfamily of cytokeratins. It has only limited sequence homologies in common with other intermediate-sized filament proteins, and these are essentially restricted to certain domains of the alpha-helical rod portion. The carboxyterminal tail sequence does not contain glycine-rich elements, thus distinguishing this cytokeratin from those acidic (type I) cytokeratins that are characterized by this feature. The similarities and differences between cytokeratin no. 18 and previously described epidermal cytokeratins are discussed in relation to the differences in the stability of the complexes which this cytokeratin forms with basic (type II) cytokeratins, as well as in relation to possible functional differences of cytokeratins in simple and stratified epithelia. 相似文献
6.
G Zummo A Palma G Peri B Valentino 《Bollettino della Società italiana di biologia sperimentale》1984,60(1):153-156
Many Authors described primary 9+0 cilia in different tissue of different animal species. In relation to the study on the ultrastructural architecture of the embryonic heart of a elasmobranch "Scyllium stellare", we saw some primary 9+0 cilia in very undifferentiated heart tissue. The hearts dissected from the Scyllium stellare embryo at 6 months of gestation, were processed for the observations at the transmission electron microscope. The cilia are found in deep invagination of the plasma membrane, near the Golgi complex and in the perinuclear region. Various functions have been postulated for the primary 9+0 cilia. 相似文献
7.
Changes of membrane fluidity in chemotactic peptide-stimulated polymorphonuclear leukocytes 总被引:1,自引:0,他引:1
M Valentino M Governa R Fiorini G Curatola 《Biochemical and biophysical research communications》1986,141(3):1151-1156
Although the phenomenon of stimulus-response coupling in polymorphonuclear leukocytes involves a series of membrane events the influence of stimulation on membrane fluidity is to clarify. In our experiments we have used 1-(4-trimethylaminophenyl) 6-phenyl-1,3,5-hexatriene and 1,6-diphenyl-1,3,5-hexatriene fluorescence polarization technique to evaluate membrane fluidity in living polymorphonuclear leukocytes after stimulation with N-formyl-methyonil-leucyl-phenylalanine peptide which has a well defined membrane receptor on the plasma membrane. We report that polymorphonuclear leukocytes stimulation increases 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene polarization, only when colcemid, a microtubule disrupting drug, is added to polymorphonuclear leukocytes. This can be viewed as an indirect evidence that microtubules are involved in the control of polymorphonuclear leukocytes membrane fluidity. On the contrary no changes have been observed with 1,6-diphenyl-1,3,5-hexatriene. This study indicates the potential use of 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene to evaluate the involvement of plasma membrane physical state during intact cell activity. 相似文献
8.
Purification and identification of dTDP-oleandrose, the precursor of the oleandrose units of the avermectins 总被引:2,自引:0,他引:2
M D Schulman S L Acton D L Valentino B H Arison 《The Journal of biological chemistry》1990,265(28):16965-16970
The nucleotide sugar precursor of the oleandrose units of the avermectins has been purified from a mutant of Streptomyces avermitilis, which does not synthesize any avermectins but which converts avermectin aglycones to their respective disaccharides. This precursor has been identified as dTDP-oleandrose. The purification was achieved by anion exchange and reverse phase high performance liquid chromatography. The purified nucleotide sugar had an absorption spectra characteristic of thymidine, released dTMP when treated with phosphodiesterase, and possessed an NMR spectrum in which three resonances characteristic of oleandrose were seen in addition to the thymidine signals. The enzyme, avermectin aglycone dTDP-oleandrose glycosyltransferase, which catalyzes the stepwise addition of oleandrose to the avermectin aglycones, has been demonstrated in cell-free extracts and (NH4)2SO4 fractions of cell-free extracts of S. avermitilis. The enzyme is specific for dTDP-oleandrose as the glycosyl donor but utilizes all avermectin aglycones as glycosyl acceptors. The stoichiometry between dTDP-oleandrose consumed in the reaction and oleandrose units transferred to the avermectin mono- and disaccharide was found to be 1:1. 相似文献
9.
Rossella Valentino Vittoria D’Esposito Federica Passaretti Antonietta Liotti Serena Cabaro Michele Longo Giuseppe Perruolo Francesco Oriente Francesco Beguinot Pietro Formisano 《PloS one》2013,8(12)
Current evidence indicates that chemical pollutants may interfere with the homeostatic control of nutrient metabolism, thereby contributing to the increased prevalence of metabolic disorders. Bisphenol-A (BPA) is a lipophilic compound contained in plastic which is considered a candidate for impairing energy and glucose metabolism. We have investigated the impact of low doses of BPA on adipocyte metabolic functions. Human adipocytes derived from subcutaneous adipose tissue and differentiated 3T3-L1 cells were incubated with BPA, in order to evaluate the effect on glucose utilization, insulin sensitivity and cytokine secretion. Treatment with 1nM BPA significantly inhibited insulin-stimulated glucose utilization, without grossly interfering with adipocyte differentiation. Accordingly, mRNA levels of the adipogenic markers PPARγ and GLUT4 were unchanged upon BPA exposure. BPA treatment also impaired insulin-activated receptor phosphorylation and signaling. Moreover, adipocyte incubation with BPA was accompanied by increased release of IL-6 and IFN-γ, as assessed by multiplex ELISA assays, and by activation of JNK, STAT3 and NFkB pathways. Treatment of the cells with the JNK inhibitor SP600125 almost fully reverted BPA effect on insulin signaling and glucose utilization. In conclusion, low doses of BPA interfere with inflammatory/insulin signaling pathways, leading to impairment of adipose cell function. 相似文献
10.
A new species, Plagiostachys lourdesiae, from Mindanao, Philippines is described here. Plagiostachys escritorii, which also occurs in Mindanao, is the most closely related species. The new species differs from P. escritorii in its petiolate lamina, lax inflorescence, red and strongly curved upward labellum, and globose to subglobose maroon fruit. A colour plate, notes on its distribution, habitat, phenology, conservation status as well as a key to Plagiostachys species in the Philippines are provided. 相似文献