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1.
Francesca Passaretta Domenico Bosco Lucia Centurione Maria Antonietta Centurione Fabio Marongiu Roberta Di Pietro 《Journal of cellular and molecular medicine》2020,24(7):4350-4355
Human Amniotic Epithelial Cells (hAEC) isolated from term placenta are a promising source for regenerative medicine. However, it has long been debated whether the hAEC population consists of heterogeneous or homogeneous cells. In a previous study, we investigated the characteristics of hAEC isolated from four different regions of the amniotic membrane finding significant heterogeneity. The aim of this study was to evaluate the hepatic differentiation capability of hAEC isolated from these four regions. Human term placentae were collected after caesarean section and hAEC were isolated from four regions of the amniotic membrane (R1-R4, according to their relative distance from the umbilical cord) and treated in hepatic differentiation conditions for 14 days. hAEC-derived hepatocyte-like cells showed marked differences in the expression of hepatic markers: R4 showed higher levels of Albumin and Hepatocyte Nuclear Factor (HNF) 4α whereas R1 expressed higher Cytochrome P450 enzymes, both at the gene and protein level. These preliminary results suggest that hAEC isolated from R1 and R4 of the amniotic membrane are more prone to hepatic differentiation. Therefore, the use of hAEC from a specific region of the amniotic membrane should be taken into consideration as it could have an impact on the outcome of therapeutic applications. 相似文献
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J Stachura M Pietroń K Nowak Z Rudzki W Nowak 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》1989,27(4):227-231
DAKO quick staining kits were used to immunostainings for Epithelial Membrane Antigen (EMA) Neuron Specific Enolase (NSE) and S-100 protein (S-100) in 18 carcinoid tumors of the gastrointestinal tract classified according to Soga and Tazawa. EMA was always absent in carcinoid tumors, being at the same time present within glandular epithelium. 88% of cases showed positive immunostaining for NSE. S-100 immunostaining showed immunopositive stellate cells present within the tumor especially within type A carcinoids. In addition in one carcinoid tumor thick, strongly S-100 positive bundles were noticed at the periphery of nests of tumor cells. Combined immunohistochemical and ultrastructural studies are needed to elucidate interrelation of neoplastic and neural elements within carcinoid tumorsa. 相似文献
4.
Giuseppe Familiari M.D. Stefania A. Nottola Antonio Familiari Pietro M. Motta 《Cell and tissue research》1989,257(2):247-253
Summary The present study provides further details on the fine-structural three-dimensional architecture of the zona pellucida (ZP) in growing and atretic follicles of mice by use of ruthenium red in combination with the detergents Triton X100 and saponin. These detergents were used for extraction of the soluble fraction of the zonal proteins in an attempt to expose the structural zonal glycoproteins, which in turn can be viewed as minute three-dimensional networks upon transmission- and scanning electron-microscopic examination. By use of these methods, the ZP of growing follicles appeared to be formed by interconnected filaments which also bind to globular structures building up a three-dimensional lattice. In contrast, the ZP of stage I as well as other (II and III) stages of atretic follicles showed a structure characterized by the presence of closely packed granules connected with short filaments to form a close-mesh reticulum. This structural change of the ZP, which in the present study is also associated with the disappearance of gap junctions within the granulosa and cumulus cell population, might represent one of the early events involved in the onset of atresia. These changes, most probably depending on an altered secretory activity of both oocytes and follicle cells, might lead to a degradation of the ZP network structure and to its subsequent increased density (condensation). All these morphodynamic events eventually contribute to a sequestration of the oocyte in the early stage of atresia. 相似文献
5.
Lipid characteristics of Friend erythroleukaemia cells differentiated by dimethyl sulphoxide or hexamethylenebisacetamide, and of non-inducible clones treated with the inducers. 下载免费PDF全文
We have compared the effects of pretreatment of Swiss 3T3 cell with pertussis toxin on the stimulation of DNA synthesis and phosphoinositide hydrolysis in response to a wide variety of mitogens. The toxin substantially inhibited the stimulation of DNA synthesis in response to a phorbol ester or various peptide and polypeptide growth factors irrespective of their ability to activate phosphoinositidase C. Production of inositol phosphates in response to platelet-derived growth factor, fibroblast growth factor and prostaglandin F2 alpha were unaffected by the toxin while bombesin- and vasopressin-stimulated formation of inositol phosphates were inhibited by only 27 and 23% respectively. These results argue against a major role for a pertussis toxin-sensitive G protein in coupling any of these mitogen receptors to activation of a phosphoinositidase C. Furthermore, the results suggest that the widespread inhibitory effects of pertussis toxin on mitogen-stimulated DNA synthesis may be unrelated to the toxin's limited actions on phosphoinositide hydrolysis. 相似文献
6.
Anna Maria Greco Pasquale Gambardella Raffaella Sticchi Diego D'aponte Pietro De Franciscis 《Chronobiology international》1988,5(3):217-225
Circadian rhythms of serotonin (5HT), its precursors tryptophan (TP) and 5-hydroxy-tryptophan (5HTP) and its acid catabolite 5-hydroxy-indoleacetic acid (5HIAA), were determined in the hypothalamus of control rats and rats which had been treated continuously with subcutaneous imipramine (10 mg/kg/day) for 2 weeks.
Rats were individually housed and entrained to LD12:12. Controls showed the 5HT and TP peaks in the light and dark periods respectively, as reported in the literature, but no inverted correlation (antiphase) between SHT and 5HIAA rhythms.
Imipramine significantly modified circadian rhythm characteristics: the 5HT acrophase was advanced, that of TP and 5HIAA was delayed. Imipramine also significantly increased hypothalamic SHT and TP concentrations. 相似文献
Rats were individually housed and entrained to LD12:12. Controls showed the 5HT and TP peaks in the light and dark periods respectively, as reported in the literature, but no inverted correlation (antiphase) between SHT and 5HIAA rhythms.
Imipramine significantly modified circadian rhythm characteristics: the 5HT acrophase was advanced, that of TP and 5HIAA was delayed. Imipramine also significantly increased hypothalamic SHT and TP concentrations. 相似文献
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Chemical modification of essential carboxyl group and histidine residue in the plasma-membrane 5'-nucleotidase 总被引:1,自引:0,他引:1
J Harb K Meflah A di Pietro S Bernard D C Gautheron 《Biochimica et biophysica acta》1986,870(2):320-326
An investigation, using specific chemical reagents, of the amino acids involved in the catalytic activity of the purified 5'-nucleotidase (5'-ribonucleotide phosphohydrolase, EC 3.1.3.5) from bovine liver plasma membranes, was carried out. The enzyme was irreversibly inactivated by N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ). The inhibition kinetics were of the first-order type and decreased partially in the presence of nucleotides and divalent cations. These results indicate for the first time that a carboxyl group is essential for the catalytic process of 5'-nucleotidase. Moreover, chemical modification by diethylpyrocarbonate also produced inactivation of the enzyme and showed a differential spectrum with a peak at 240 nm characteristic of N-carbethoxyhistidine residues. This inactivation was efficiently released upon decarbethoxylation by hydroxylamine only when the extent of inactivation, due to low concentration of diethylpyrocarbonate, was limited. The time-dependent inactivation followed first-order kinetics and nucleotides afforded significant protection against diethylpyrocarbonate modification. The results indicate the involvement of the histidine residue in catalysis. 相似文献
9.
Nicotinamide mononucleotide adenylyltransferase. Molecular and enzymatic properties of the homogeneous enzyme from baker's yeast 总被引:1,自引:0,他引:1
Nicotinamide mononucleotide (NMN) adenylyltransferase has been purified to homogeneity from baker's yeast crude extract. The purification procedure is relatively simple and consists of high-salt extraction of enzyme activity and precipitation with poly(ethylenimine), followed by ion-exchange and dye ligand chromatography separations. The final enzyme preparation is homogeneous as judged by a single Coomassie blue stainable band when run on nondenaturating and denaturating polyacrylamide gels. The native enzyme shows a molecular weight of about 200 000, calculated by gel filtration and sucrose gradient centrifugation. The protein possesses quaternary structure and is composed of four apparently identical Mr 50 000 subunits. The absorption spectrum shows a maximum at 280 nm and a minimum at 253 nm. The isoelectric point is 6.2. Amino acid composition analysis shows the presence of 28 half-cystine residues. The same result has been obtained by titrating the enzyme in denaturating conditions with Ellman's reagent after incubation with sodium borohydride. NMN adenylyltransferase is a glycoprotein containing 2% sugar, 2 mol of alkali-labile phosphate per mole of enzyme, and 1 mol of adenine moiety per mole of enzyme. Therefore, the possibility that the enzyme is ADP-ribosylated exists. The Km values for ATP, NMN, and nicotinate mononucleotide are 0.11 mM, 0.19 nM, and 5 mM, respectively. Kinetic analysis reveals a behavior that is consistent with an ordered sequential Bi-Bi mechanism. The pH optimum is in the range 7.2-8.4. 相似文献
10.
Giuseppe Familiari MD Vincenzo Toscano Pietro M. Motta 《Cell and tissue research》1985,240(3):519-528
Summary Morphological alterations induced by dehydroepiandrosterone (DHA) were studied in polycystic mouse ovaries (PCO). Treated mice showed ovulatory failure and cystic changes; cysts and follicles in various stages of growth and atresia were present although corpora lutea were absent. The levels of testosterone, dihydrotestosterone, 3- and 3-androstanediol, estrone and androstenedione increased, whereas estradiol was not detectable.The ultrastructure of granulosa cells in healthy and atretic follicles was similar to that of control animals, although the membrana granulosa in cysts was reduced to a monolayer of flattened cells. The theca interna of healthy and atretic follicles and ovarian cysts showed ultrastructural signs of abnormal steroidogenic stimulation.No significant differences (0.7<P<0.8) were found between the extensive surface area of gap junctions of healthy follicles of control and DHA-treated animals. On the P-face of granulosa cells of large healthy follicles, meandering strands of tight junctional particles were observed; their average length was significantly longer than those in healthy follicles of control animals (P<0.001). This increase was probably related to the large amounts of androgens present in the treated animals.Theca interna cells possessed small gap junctions; no significant differences (P>0.9) in gap-junction surface area were observed between DHA-treated and control animals. These results suggest that the size of gap junctions is probably unrelated to the steroidogenic activities of theca cells.The following trivial names have been used: Dihydrotestosterone: 5-androstan 17 ol-13 one; 3-androstanediol: 5-androstan 3,17 diol; 3-androstanediol: 5-androstan 3,17 diol 相似文献