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1.
Qualitative and quantitative observations on the structure of the Schwann cells in myelinated fibres
E Pannese M Ledda G Arcidiacono D Frattola L Rigamonti P Procacci 《Acta anatomica》1988,131(4):314-326
Various morphological features of the Schwann cells of myelinated fibres in the lizard thoracic spinal roots were studied, and, when possible, quantified using morphometric methods. About 0.8% of the Schwann cells are binucleate and some display clusters of microvilli along the internodes. The percentages of the cytoplasmic area of the Schwann cell occupied by the following cytoplasmic components were determined: mitochondria, Golgi apparatus, granular endoplasmic reticulum, smooth endoplasmic reticulum, multivesicular bodies, dense bodies, autophagic vacuoles, peroxisome-like bodies, lipofuscin granules and lipid droplets. Linear relationships were found between the sectional areas of the mitochondria and granular endoplasmic reticulum of the Schwann cell and both the length of the profile of the Schwann cell plasma membrane and the size of the related axon. The results obtained are compatible both with the hypothesis that the mitochondria and granular endoplasmic reticulum of the Schwann cell are involved in the production and storage of proteins for the plasma membrane of this cell, and with the hypothesis that these organelles are involved in the production and storage of protein metabolites which are subsequently transferred to the related axons. 相似文献
2.
G M Ledda A Columbano P M Rao S Rajalakshmi D S Sarma 《Biochemical and biophysical research communications》1980,95(2):816-821
In order to characterize rat liver DNA replicated on a carcinogen-damaged template, the replicated DNA was treated with S1-nuclease and the release of (14C)-dimethyl-nitrosamine induced 06-methylguanine, a lesion associated with miscoding and N-7-methylguanine, a lesion that does not miscode were monitored. The results indicated that both the methylated guanines became susceptible to S1-nuclease upon replication. However, a greater percentage of 06-methylguanine (22% of the total 06-methylguanine present in the DNA) compared to N-7-methylguanine (4% of the total N-7-methylguanine present in the DNA) was rendered acid soluble by S1-nuclease. The preferential release of 06-methylguanine compared to N-7-methylguanine from replicated DNA was interpreted to indicate its occurrence in local denatured regions probably generated as a result of misbase pairing. 相似文献
3.
Milford H. Wolpoff Fred H. Smith Mirko Malez Jakov Radov
i Darko Rukavina 《American journal of physical anthropology》1981,54(4):499-545
Human remains excavated from Vindija cave include a large although fragmentary sample of late Mousterian-associated specimens and a few additional individuals from the overlying early Upper Paleolithic levels. The Mousterian-associated sample is similar to European Neandertals from other regions. Compared with earlier Neandertals from south central Europe, this sample evinces evolutionary trends in the direction of Upper Paleolithic Europeans. Compared with the western European Neandertals, the same trends can be demonstrated, although the magnitude of difference is less, and there is a potential for confusing temporal with regional sources of variation. The early Upper Paleolithic-associated sample cannot be distinguished from the Mousterian-associated hominids. We believe that this site provides support for Hrdli?ka's “Neandertal phase” of human evolution, as it was originally applied in Europe. 相似文献
4.
Grzegorz Garbacz Bartosz Kołodziej Mirko Koziolek Werner Weitschies Sandra Klein 《AAPS PharmSciTech》2013,14(2):517-522
The bicarbonate buffer is considered as the most biorelevant buffer system for the simulation of intestinal conditions. However, its use in dissolution testing of solid oral dosage forms is very limited. The reason for this is the thermodynamic instability of the solution containing hydrogen carbonate ions and carbonic acid. The spontaneous loss of carbon dioxide (CO2) from the solution results in an uncontrolled increase of the pH. In order to maintain the pH on the desired level, either a CO2 loss must be completely avoided or the escaped CO2 has to be replaced by quantitative substitution, i.e. feeding the solution with the respective amount of gas, which re-acidifies the buffer after dissociation. The present work aimed at the development of a device enabling an automatic pH monitoring and regulation of hydrogen carbonate buffers during dissolution tests. 相似文献
5.
Rosangela Catoni Francesco Bracco Mirko U. Granata 《Physiology and Molecular Biology of Plants》2020,26(2):261-270
Mesophyll conductance (gm) has received over time much less attention than stomatal conductance (gs), although it affects leaf photosynthesis to about the same extent as stomatal conductance does. The objective of this study was to analyze the gm trend in five understory herbaceous species growing in a close-canopy forest in the north-west of Italy. In particular, three of analyzed species were monocots: Carex brizoides Lam., Carex pilosa Scop., and Oplismenus undulatifolius P. Beauv and the others dicots species: Circaea lutetiana L., and Pulmonaria officinalis Ced. The results showed, on one hand, the absence of correlation between gm and the considered environmental variables in the forest understory (i.e. air temperature, photosynthetic photon flux density and carbon dioxide concentration). Moreover, we carried out a principal component analysis considering all the analyzed morphological and physiological variables for the five species. The following correlation between the first component, related to the leaf mass per unit of leaf area and the leaf tissue density, and gm seem to suggest a key role of the leaf structural features in determining gm variations across the five species. 相似文献
6.
Integrated requirement of non‐specific and sequence‐specific DNA binding in Myc‐driven transcription
7.
8.
Marilisa Villano Annalisa Borghini Mirko Manetti Erica Gabbrielli Antonella Rossi Piersante Sestini Anna Franca Milia Francesca Nacci Serena Guiducci Marco Matucci-Cerinic Lidia Ibba-Manneschi Elisabetta Weber 《Arthritis research & therapy》2013,15(4):R90
Introduction
Systemic sclerosis (SSc) is a connective tissue disorder characterized by endothelial cell injury, autoimmunity and fibrosis. The following three fibrillin-1 alterations have been reported in SSc. (1) Fibrillin-1 microfibrils are disorganized in SSc dermis. (2) Fibrillin-1 microfibrils produced by SSc fibroblasts are unstable. (3) Mutations in the FBN1 gene and anti-fibrillin-1 autoantibodies have been reported in SSc. Fibrillin-1 microfibrils, which are abundantly produced by blood and lymphatic microvascular endothelial cells (B-MVECs and Ly-MVECs, respectively), sequester in the extracellular matrix the latent form of the potent profibrotic cytokine transforming growth factor β (TGF-β). In the present study, we evaluated the effects of SSc sera on the deposition of fibrillin-1 and microfibril-associated glycoprotein 1 (MAGP-1) and the expression of focal adhesion molecules by dermal B-MVECs and Ly-MVECs.Methods
Dermal B-MVECs and Ly-MVECs were challenged with sera from SSc patients who were treatment-naïve or under cyclophosphamide (CYC) treatment and with sera from healthy controls. Fibrillin-1/MAGP-1 synthesis and deposition and the expression of αvβ3 integrin/phosphorylated focal adhesion kinase and vinculin/actin were evaluated by immunofluorescence and quantified by morphometric analysis.Results
Fibrillin-1 and MAGP-1 colocalized in all experimental conditions, forming a honeycomb pattern in B-MVECs and a dense mesh of short segments in Ly-MVECs. In B-MVECs, fibrillin-1/MAGP-1 production and αvβ3 integrin expression significantly decreased upon challenge with sera from naïve SSc patients compared with healthy controls. Upon challenge of B-MVECs with sera from CYC-treated SSc patients, fibrillin-1/MAGP-1 and αvβ3 integrin levels were comparable to those of cells treated with healthy sera. Ly-MVECs challenged with SSc sera did not differ from those treated with healthy control sera in the expression of any of the molecules assayed.Conclusions
Because of the critical role of fibrillin-1 in sequestering the latent form of TGF-β in the extracellular matrix, its decreased deposition by B-MVECs challenged with SSc sera might contribute to dermal fibrosis. In SSc, CYC treatment might limit fibrosis through the maintenance of physiologic fibrillin-1 synthesis and deposition by B-MVECs. 相似文献9.
10.
Riccardo Flamini Mirko De Rosso Fabiola De Marchi Antonio Dalla Vedova Annarita Panighel Massimo Gardiman Itay Maoz Luigi Bavaresco 《Metabolomics : Official journal of the Metabolomic Society》2013,9(6):1243-1253
Suspect screening analysis is a targeted metabolomics approach in which identification of compounds relies on specific available information such as their molecular formula and isotopic pattern. This method was applied to the study of grape metabolomics with an UPLC/MS high-resolution Q-TOF mass spectrometer (nominal resolution 40,000) coupled with a Jet Stream ionization source. The present paper describes the detailed qualitative and quantitative study of grape stilbenes, the principal polyphenols associated with the beneficial effects of drinking wine. For identification of compounds, a new database was expressly constructed from the molecular information of potential metabolites of grape and wine from the literature and other electronic databases. Currently, GrapeMetabolomics contains about a thousand putative grape compounds. If untargeted analysis of a sample provides identification of a new compound with a sufficiently confident score, it is added to the database. Thus, by increasing the number of samples studied, GrapeMetabolomics can be expanded. This method is effective for identification of the molecular formulae of several hundred metabolites in two runs (positive and negative ionization) with minimal sample preparation, and can also be used to analyse some single classes of compounds involved in cell and tissue metabolism. With this approach, a total of 18 stilbene derivatives was identified in two grape samples (Raboso Piave and Primitivo) on the basis of accurate mass measurements and isotopic patterns, and identification was confirmed by MS/MS analysis. The approach can also potentially be applied to the metabolomics of other plant varieties. 相似文献