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81.
Astrocytic but not neuronal increased expression and redistribution of parkin during unfolded protein stress 总被引:4,自引:0,他引:4
Parkin is a ubiquitin ligase that facilitates proteasomal protein degradation and is involved in a common autosomal recessive form of Parkinson's disease. Its expression is part of the unfolded protein response in cell lines where its overexpression protects against unfolded protein stress. How parkin expression is regulated in brain primary cells under stress situations is however, less well established. Here, the cellular and subcellular localization of parkin under basal conditions and during unfolded protein stress was investigated in primary cultures of rat astrocytes and hippocampal neurons. Immunofluorescense microscopy and biochemical analysis demonstrated that parkin is mainly associated with the endoplasmic reticulum (ER) in hippocampal neurons while it is associated with Golgi membranes, the nuclei and light vesicles in astrocytes. The constitutive parkin expression was high in neurons as compared with astrocytes. However, unfolded protein stress elicited a selective increase in astrocytic parkin expression and a change in distribution, whereas neuronal parkin remained largely unmodified. The cell specific differences argue in favour of different cellular binding sites and substrates for the protein and a pathogenic role for astrocytes in Parkinson's disease caused by parkin dysfunction. 相似文献
82.
83.
Sayagués JM Tabernero MD Maillo A Díaz P Rasillo A Bortoluci A Gomez-Moreta J Santos-Briz A Morales F Orfao A 《Cytometry》2002,50(3):153-159
OBJECTIVE: Although information on the cytogenetic characteristics of meningioma tumors has accumulated progressively over the past few decades, information on the genetic heterogeneity of meningiomas is still scanty. The aim of the present study was to analyze by interphase fluorescence in situ hybridization (FISH) the incidence of numerical abnormalities for chromosomes 1, 9, 10, 11, 14, 15, 17, 22, X, and Y in a group of 70 consecutive meningioma tumors. Another goal was to establish the potential associations among the altered chromosomes, as a way to assess both intertumoral and intratumoral heterogeneity. METHODS: For the purpose of the study, 70 patients diagnosed with meningioma were analyzed. Interphase FISH for the detection of numerical abnormalities for chromosomes 1, 9, 10, 11, 14, 15, 17, 22, X, and Y was applied to fresh tumor samples from each of the patients studied. RESULTS: The overall incidence of numerical abnormalities was 76%. Chromosome Y in males and chromosome 22 in the whole series were the most common abnormalities (46% and 61%, respectively). Despite the finding that monosomy of chromosome 22/22q(-) deletions are the most frequent individual abnormality (53%), we have observed that chromosome gains are significantly more common than chromosome losses (60% versus 40%). Chromosome gains corresponded to abnormalities of chromosomes 1 (27%), 9 (25%), 10 (23%), 11 (22%), 14 (33%), 15 (22%), 17 (23%), and X in females (35%) and males (23%) whereas chromosome losses apart from chromosome 22 frequently involved chromosomes 14 (19%), X in males (23%), and Y in males (32%). Although an association was found among most gained chromosomes on one side and chromosome losses on the other side, different association patterns were observed. Furthermore, in the latter group, monosomy 22/22q(-) was associated with monosomy X in females and monosomy 14/14q(-) was associated with nulisomy Y in males. In addition, chromosome losses usually involved a large proportion of the tumor cells whereas chromosome gains were restricted to small tumor cell clones, including tetraploid cells. CONCLUSIONS: Our results show that meningiomas are genetically heterogeneous tumors that display different patterns of numerical chromosome changes, as assessed by interphase FISH. 相似文献
84.
Gene therapy of erectile dysfunction in the rat with penile neuronal nitric oxide synthase 总被引:3,自引:0,他引:3
Magee TR Ferrini M Garban HJ Vernet D Mitani K Rajfer J Gonzalez-Cadavid NF 《Biology of reproduction》2002,67(3):1033-1041
Gene transfer to the penile corpora cavernosa of constructs of the inducible and endothelial nitric oxide synthase (NOS) cDNAs ameliorates erectile dysfunction in aged rats. In this study, we investigated whether the neuronal NOS (nNOS) variant responsible for erection, penile nNOS (PnNOS), can exert a similar effect, and whether the combination of electroporation with a helper-dependent adenovirus (AdV) improves gene transfer. PnNOS and beta-galactosidase cDNAs were cloned in plasmid (pCMV-PnNOS; pCMV-beta-gal) and "gutless" AdV (AdV-CMV-PnNOS; AdV-CMV-beta-gal) vectors, and injected into the penis of adult (beta-gal) or aged (PnNOS) rats, with or without electroporation. Penile erection was measured at different times after PnNOS cDNA injection, by electrical field stimulation of the cavernosal nerve. The expression of beta-galactosidase or PnNOS was estimated in penile tissue by either histochemistry and luminometry or Western blot, and the effects of AdV-CMV-PnNOS on mRNA expression were examined by a DNA microarray. We found that electroporation increased pCMV-beta-gal uptake, and its expression was detectable at 56 days. In the aged rats treated with pCMV-PnNOS and electroporation, the maximal intracavernosal:mean arterial pressure ratios were elevated for 11 and 18 days when compared with those in controls. Electroporation intensified penile uptake of as few as 10(6) viral particles (vp) of AdV-CMV-beta-gal, and with 10(7) vp beta-galactosidase was still detectable at 60 days. Electroporated AdV-CMV-PnNOS (10(7) vp) was effective at 18 days in stimulating the erection of aged rats, without inducing the expression of cytotoxic genes. In conclusion, intracavernosal gene therapy with PnNOS cDNA corrected the aging-related erectile dysfunction for at least 18 days when given by electroporation in a helper-dependent AdV at low viral loads. 相似文献
85.
86.
Ortiz CM Castro IP Portilla LB Aranda PD Arizmendi Mdel C 《Phytochemical analysis : PCA》2003,14(5):319-324
An instrumental method based on a chemometric model of the medium region of the infrared (MIR) was developed to analyse total sugar content and the proportions of glucose, fructose and sucrose. In order to construct the model, a set of 127 standard aqueous solutions of different sugars in the concentration range 0-20% (w/v) were prepared and analysed in the interval 4900-700 cm(-1). The MIR was transformed by normalisation, correction of baseline using the second derivative, and suppression of the signals of water and carbon dioxide. The region between 1150 and 950 cm(-1) showed the highest correlation between signal and concentration. The correlation coefficient for total sugar content was 0.956, whilst those for glucose, fructose and sucrose were 0.982, 0.972 and 0.992, respectively. The method was validated using a set of 28 samples of nectar which had been assayed by chromatographic and refractometric methods. The method shows potential utility for the prediction of nectar sugar components. 相似文献
87.
Silvestre MD Lagarda MJ Farré R Martínez-Costa C Brines J Molina A Clemente G 《Biological trace element research》2000,76(3):217-227
The aim of this study was to establish the possible effects of the sampling protocol (between-breast, within-feed, and diurnal
differences) and the mother’s personal factors (age, parity, iron supple-mentation, smoking habits, and lactation period)
on the copper, iron, and zinc contents in human milk.
One hundred thirty-six human milk samples identified by their origin and sampling conditions were analyzed. The samples were
obtained from the 2nd to 15th d postpartum from 62 women. The data on the individuals required for the study were available.
Mineral determinations were analyzed by flame atomic absorption spectrometry following a standarized protocol.
The results showed that iron contents were higher in hind-milk samples and at the nighttime feeding and depended on the breast
from which the sample was taken. The copper and zinc concentrations showed no significant variations. There was no significant
relationship among the mothers’ age, parity, smoking habits, iron supplementation, and copper content. Milk from older women
had lower zinc contents than that of younger women. Increased amounts of iron were found in multiparous women. Between colostrum
and transitional milk, a sharp decrease in zinc content was observed, whereas copper and iron contents remained constant.
All of these results make it clear that standardized sampling protocols are needed in order to obtain comparable values. 相似文献
88.
Black, Jewish, and Interracial: It's Not the Color of Your Skin but the Race of Your Kin, and Other Myths of Identity. Katya Gibel Azoulay. Durham, NC: Duke University Press, 1997.220 pp. 相似文献
89.
S. R. Gordon Dolores Czerwinski-Mowers Jeannette Marchand Rosemary Shuffett 《Histochemistry and cell biology》1998,110(3):251-262
Binding, internalization, and movement of hemeproteins and peroxidase-conjugated lectins across organ cultured rat corneal
endothelia has been investigated. Horseradish peroxidase (HRP) type II, bound to the surface, was minimally internalized and
was easily washed off. In contrast, HRP-VI bound and was rapidly internalized. Reaction product was observed in vesicles,
endosomes, multivesicular bodies, and extended along the length of the intercellular space (ICS) to Descemet’s membrane. Studies
at 4° C indicated HRP-VI bound uniformly along the surface in a punctate fashion. Exposure to polylysine or mannose significantly
decreased uptake. Other tracers such as HRP-VIII, -IX, catalase, and microperoxidase exhibited limited uptake by the tissue.
However, endothelia vigorously internalized soybean agglutinin (SBA)–HRP, and reaction product was found intracellularly and
within the ICS at the cell/Descemet’s membrane interface. Internalization and the appearance of SBA–HRP within the ICS was
diminished following polylysine or mannose treatment. Experiments at 4° C indicated that SBA–HRP binding and uptake were temperature
sensitive. Wheat germ agglutinin (WGA)–HRP was also strongly endocytosed and reaction product was visualized within vesicles,
endosomes, and multivesicular bodies. Although WGA-HRP reaction product was observed within the ICS, none was detected at
the level of Descemet’s membrane. The WGA competitive sugar N-acetyl-d-glucosamine, reduced endocytosis, whereas exposure to unlabeled WGA and mannose together reduced uptake. These results indicate
endothelia exhibit differential uptake of various hemeproteins and lectins which is dependent on charge, mannose receptors,
and appropriate surface sugars.
Accepted: 3 Mach 1998 相似文献
90.
Agamospermous species account for a large proportion of the species ofLimonium. Agamospermy is indicated by uneven polyploidy or aneuploidy, low pollen stainability and by the presence of monomorphic self-incompatible populations. The taxonomic treatment of agamospermous taxa varies from recognition of all of them at the same specific rank or by utilising a range of ranks in the taxonomic hierarchy. The influence of evolutionary hypotheses on taxonomic systems is considered. Molecular data provide a means of measuring the genetical relationships of taxa and establishing groups in a taxonomic hierarchy. 相似文献