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1.
It has long been debated whether the mind consists of specialized and independently evolving modules, or whether and to what extent a general factor accounts for the variance in performance across different cognitive domains. In this study, we used a hierarchical Bayesian model to re-analyse individual level data collected on seven primate species (chimpanzees, bonobos, orangutans, gorillas, spider monkeys, brown capuchin monkeys and long-tailed macaques) across 17 tasks within four domains (inhibition, memory, transposition and support). Our modelling approach evidenced the existence of both a domain-specific factor and a species factor, each accounting for the same amount (17%) of the observed variance. In contrast, inter-individual differences played a minimal role. These results support the hypothesis that the mind of primates is (at least partially) modular, with domain-specific cognitive skills undergoing different evolutionary pressures in different species in response to specific ecological and social demands. 相似文献
2.
Detection of P-glycoprotein on endothelial and endocrine cells of the human pancreatic islets by C 494 monoclonal antibody 总被引:1,自引:0,他引:1
D. Bani M. L. Brandi C. A. Axiotis T. Bani-Sacchi 《Histochemistry and cell biology》1992,98(4):207-209
Summary P-glycoprotein, an integral membrane protein acting as an energy-dependent efflux pump, has been detected immunocytochemically in the human pancreatic islets using C 494 monoclonal antibody. Intense P-glycoprotein immunoreactivity was found in both endothelial cells of islet blood capillaries and in endocrine cells. Strong expression of P-glycoprotein has been found in the capillary blood vessels at blood-tissue barrier sites and in numerous kinds of cells with secretory/excretory function. Therefore the present findings suggest that P-glycoprotein may play a role in controlling the composition of the extracellular fluids and the intracellular milieu of endocrine islet cells and possibly in regulating their secretory activity. 相似文献
3.
Sergio Sgorbati Marisa Levi Elio Sparvoli Federica Trezzi Giovanni Lucchini 《Physiologia plantarum》1986,68(3):471-476
Cytometry and flow cytometry were used to study characteristics of fluorescence of the DNA-DAPI complex in nuclei released from different fresh and formaldehyde-fixed pea ( Pisum sativum L. cv. Lincoln) tissues. The two methods of isolation are compared and discussed as well as their possible use for quantitative analysis of DNA in plant tissues. With fixed tissues it is possible to obtain a number of nuclei sufficient for the flow cytometric analysis, even using small amounts of plant tissue. 相似文献
4.
M Le Dafniet P Garnier D Bression A M Brandi J Racadot F Peillon 《Hormones et métabolisme》1985,17(9):476-479
Specific receptors for TRH were characterized on cellular membranes of 6 out of 13 somatotrophic adenomas obtained from acromegalic patients. These receptors had the same dissociation constant (Kd: 62 +/- 10 nM) as those found in human PRL-secreting adenomas, but their maximal number of binding sites (Bmax: 76 +/- 24 fmol/mg of protein) was six fold smaller. A good correlation was found between the presence of TRH receptors and the in vitro TRH-induced stimulation of GH secretion. The increase in GH release varied from 25 to 200%. It was thus concluded that these receptors are functional. However, why only some of the human somatotrophic adenomas possess TRH receptors and respond to TRH in vitro needs further investigations. 相似文献
5.
K B Alves C M Brandi J C Souza-Pinto J A Guimar?es 《The International journal of biochemistry》1984,16(12):1295-1300
An aminopeptidase from human urine (HUA) able to hydrolyze L-aminoacyl-2-naphthylamides, L-Leu-p-nitroanilide and to convert both MLBK and LBK to BK has been further purified and characterized. The preparation now obtained showed a 3-fold higher specific activity than the previously described one and a single active protein band in 7% polyacrylamide gel electrophoresis accounting for 86% of total protein. Kinetic constants for this kinin-converting enzyme were determined using L-aminoacyl-2-naphthylamides, L-Leu-p-nitroanilide and LBK. The Km values for different naphthylamides were in the 10(-5) M range while that for L-Leu-p-nitroanilide was 3.6 X 10(-4) M. With LBK as substrate the aminopeptidase activity showed the highest catalytic efficiency in spite of a Km in the mM range. The enzyme was poorly inhibited by -SH and -S-S- group reagents. Some L-aminoacids, as well as mono- and diamines, indomethacin, puromycin and bestatin were equipotent competitive inhibitors of both arylamidase and aminopeptidase activities. Results obtained in this paper are compatible with our conclusion that human urine, unlike other enzyme sources, contains only one aminopeptidase, and that this enzyme displays both arylamidase and kinin-converting activities. The enzyme's action may be important in the metabolism of kinins, yielding peptides which could interact with both B-1 and B-2 kinin receptors in the kidney. 相似文献
6.
F Peillon A M Brandi D Bression M Le Dafniet J Racadot 《Biochemical and biophysical research communications》1983,112(1):42-46
The ability of 2-Hydroxyestradiol, a catecholestrogen, and 17 beta Estradiol to interact with the dopamine inhibition of prolactin and with dopamine receptors has been tested on dispersed human prolactin-secreting cells obtained from ten pituitary adenomas. There is a 80% inhibition of prolactin secretion obtained by addition of dopamine in a superfusion system. This inhibition is not affected by preexposure to the steroids, or by their introduction into the perifusion medium. Moreover 2 Hydroxyestradiol and 17 beta Estradiol do not interact with the binding of 3H Domperidone to DA receptors. 相似文献
7.
Giorgio Brandi Flaminio Cattabeni Amedeo Albano Orazio Cantoni 《Free radical research》1989,6(1):47-55
Escherichia coli lethality by hydrogen peroxide is characterized by two modes of killing. In this paper we have found that hydroxyl radicals (OH -) generated by H2O2 and intracellular divalent iron are not involved in the induction of mode one lethality (i.e. cell killing produced by concentrations of H2O2 lower than 2.5 mM). In fact, the OH radical scavengers, thiourea, ethanol and dimethyl sulfoxide, and the iron chelator, desferrioxarnine, did not affect the survival of cells exposed to 2.5mM H2O2. In addition cell vulnerability to the same H2O2 concentration was independent on the intracellular iron content. In contrast, mode two lethality (i.e. cell killing generated by concentrations of H2O2 higher than 10mM) was markedly reduced by OH radical scavengers and desferrioxamine and was augmented by increasing the intracellular iron content.
It is concluded that OH. are required for mode two killing of E. coli by hydrogen peroxide. 相似文献
It is concluded that OH. are required for mode two killing of E. coli by hydrogen peroxide. 相似文献
8.
Manju Basu Shu-Ai Weng Hongyu Tang Farhat Khan Federica Rossi Subhash Basu 《Glycoconjugate journal》1996,13(3):423-432
The galactosyltransferase, GalT-4, which catalyses the biosynthesisin vitro of neolactotetraosylceramide, nLcOse4Cer (Gal1-4GleNAc1-3Gal1-4Glc-Cer) from lactotriaosylceramide, LcOse3Cer (GlcNAc1-3Gal1-4Glc-Cer), and UDP-galactose has been purified 107 500-fold from a mineral oil induced mouse T-lyphoma P-1798, using affinity columns. The purified enzyme is partially stabilized in the presence of phospholipid liposomes. Two closely migrating protein bands of apparent molecular weights 56 kDa and 63 kDa were observed after sodium dodecyl sulfate polyacrylamide gel electrophoresis of highly purified mouse GalT-4. These two protein bands, when subjected to limited proteolysis, resulted in three peptides with identical mobilities indicating amino acid sequence identity between the proteins. Both protein bands from P-1798 gave a positive immunostain when tested with polyclonal antibody against bovine lactose synthetase (UDP-Gal:Glc 4-galactosyltransferase) following Western blot analysis on nitrocellulose paper. The enzyme has a pH optimum between 6.5 and 7.0 and like all other galactosyltransferases, GalT-4 has absolute requirements for divalent cation (Mn2+). TheK
m values for the substrate LcOse3Cer and donor UDP-galactose are 110 and 250 µm, respectively. Substrate competition studies with LcOse3Cer and either asialo-agalacto-1-acid glycoprotein orN-acetylglucosamine revealed that these reactions might be catalysed by the same protein. The only other glycolipid which showed acceptor activity toward the purified GalT-4 was iLcOse5Cer (GlcNAc1-1-3Gal1-4Lc3), the precursor for polylactosamine antigens. However, competition studies with these two active substrates using the most purified enzyme fraction, revealed that these two reactions might be catalysed by two different proteins since the experimental values were closer to the theoretical values calculated for two enzymes. Interestingly however, it seems that the GalT-4 from P-1798 has an absolute requirement for anN-acetylglucosamine residue in the substrate since the lyso-derivative (GlcNH21-3Gal1-4Glc-sphingosine) of the acceptor glycolipid LcOse3Cer is completely inactive as substrate while theK
m andV
max of the reacetylated substrate (GlcNac1-3Gal1-4Glc-acetylsphingosine) was comparable with LcOse3Cer. Autoradiography of the radioactive product formed by purified P-1798 GalT-4 confirmed the presence of nLcOse4Cer, as the product cochromatographed with authentic glycolipid. The monoclonal antibody IB-2, specific for nLcOse4Cer, also produced a positive immunostained band on TLC as well as giving a positive ELISA when tested with radioactive product obtained using a highly purified enzyme from mouse P-1798 T-lymphoma.Abbreviations EDTA
ethylenediamine tetraacetate
- ME
-mercaptoethanol
- PEG
polyethylene glycol
- PBS
phosphate buffered saline
- Suc
sucrose
- Mn2+
manganese
- Gal
galactose
- GlcNAc
N-acetylglucosamine
- UDP-Gal
Uridine diphosphate galactose
- Ab
antibody
- SDS
sodium dodecyl sulphate
- PAGE
polyacrylamide gel electrophoresis
- ECB
embryonic chicken brain
- Cer
ceramide
- nLc4 or NlcOse4Cer
Gal1-4GleNac1-3Gal1-4Glc-Cer, neoLactotetraosylceramide
- Lc3 or LcOse3Cer
GlcNac1-3Gal1-4Glc-Cer, lactotriaosylceramide
- iLc5
iLcOse5Cer, GlcNAc1-3nLcOse4Cer
- nLc6
nLcOse6Cer, Gal1-4iLcOse5Cer
- SA–Gal–1AGP
asialo-agalacto1-acid glycoprotein
- TLC
thin layer chromatography 相似文献
9.
Orazio Cantoni Giorgio Brandi Amedeo Albano Flaminio Cattabeni 《Free radical research》1995,22(3):275-283
Cystine markedly enhanced the cytotoxic response of Escherichia coli cells to concentrations of hydrogen peroxide resulting in mode one killing, but displayed little effect in mode two killed cells. The effect of cystine was concentration-dependent over a range of 5-50 μM and did not further increase at higher levels. Cystine had similar effects in other bacterial systems.
In order to sensitize the cells to the oxidative injury, the amino acid must be present during exposure to the oxidant since no enhancement of the cytotoxic response can be observed in cystine pre-loaded cells. In addition, no further enhancement of cytotoxicity could be detected when cystine was added before and left during challenge with the oxidant. The enhancing effect of cystine on oxidative injury of E. coli cells appears to be directly mediated by the amino acid and in fact cysteic acid, the most likely oxidation product, had no effect on the killing of bacterial cells elicited by hydrogen peroxide. Other disulfide compounds such as oxidized glutathione, cystamine and dithionitrobenzoic acid only slightly increased the susceptibility of bacteria to the oxidant. The effect of the disulfides was not concentration-dependent over a range of 200-800 μM and was statistically significant only for cystamine.
Taken together, these results indicate that cystine markedly increases the cytotoxic response of bacteria to hydrogen peroxide and suggest that the amino acid might impair the cellular defence machinery against hydrogen peroxide. This effect may involve a thiol-disulfide exchange reaction at the cell membrane level. 相似文献
In order to sensitize the cells to the oxidative injury, the amino acid must be present during exposure to the oxidant since no enhancement of the cytotoxic response can be observed in cystine pre-loaded cells. In addition, no further enhancement of cytotoxicity could be detected when cystine was added before and left during challenge with the oxidant. The enhancing effect of cystine on oxidative injury of E. coli cells appears to be directly mediated by the amino acid and in fact cysteic acid, the most likely oxidation product, had no effect on the killing of bacterial cells elicited by hydrogen peroxide. Other disulfide compounds such as oxidized glutathione, cystamine and dithionitrobenzoic acid only slightly increased the susceptibility of bacteria to the oxidant. The effect of the disulfides was not concentration-dependent over a range of 200-800 μM and was statistically significant only for cystamine.
Taken together, these results indicate that cystine markedly increases the cytotoxic response of bacteria to hydrogen peroxide and suggest that the amino acid might impair the cellular defence machinery against hydrogen peroxide. This effect may involve a thiol-disulfide exchange reaction at the cell membrane level. 相似文献
10.
G. Fiorelli F. Gori L. Masi U. Frediani M. L. Brandi A. Tanini P. A. Bernabei R. T. Ballock L. M. Wakefield M. B. Sporn 《Journal of cellular physiology》1994,160(3):482-490
Increasing evidence suggests that transforming growth factor-β (TGF-β) is involved in bone formation during remodeling. Using a recently cloned human leukemic cell line (FLG 29.1 cells) we demonstrate that these cells synthesize and secrete TGF-β1 and that exogenous or autocrine TGF-β1 can induce the same features of osteoclastic-like cells, exerting its effects through the binding to TGF-β specific receptors. Scatchard analysis of 125I-labeled TGF-β1 to FLG 29.1 cells revealed the presence of a single high affinity binding site with a Kd value of ~25 pM and a binding capacity of ~900 sites/cell. Affinity labeling experiments showed that FLG 29.1 cells express type I and type II TGF-β receptors. Stimulation of FLG 29.1 cells with low TGF-β1 doses reduced cell proliferation and increased cell adhesion and tartrate resistant acid phosphatase (TRAcP) activity. Pretreatment of FLG 29.1 cells with TGF-β1 caused a significant and dose-dependent response to calcitonin. Northern blot of total mRNA and analysis of the conditioned media (CM) showed that TGF-β1 was synthesized by FLG 29.1 cells. TPA treatment, which induces partial differentiation of these cells, markedly increased TGF-β1 mRNA expression and growth factor release. The majority of TGF-β1 secreted by TPA-treated cells was in its latent form. However, anti-TGF-β antibodies inhibited TGF-β1 and TPA-induced growth inhibition, calcitonin responsiveness, and TRAcP activity, suggesting that the TPA effect is mediated in part by autocrine TGF-β1 and indicating that the cells can activate and respond to the TGF-β that they secrete. These findings support a potential autocrine role for TGF-β1 in osteoclast differentiation. © 1994 Wiley-Liss, Inc. 相似文献