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171.
Since previous work had shown that brain D2 3,4-dihydroxyphenylethylamine (dopamine) receptors were only partly converted from their high-affinity state to their low-affinity state, we here tested whether it was possible to obtain a complete 100% conversion of these receptors into their low-affinity state. It was first essential to resolve the components of [3H]spiperone binding to dopaminergic sites and nondopaminergic sites in rat striatal homogenates. In the presence of 50 microM S-sulpiride (to occlude the dopaminergic sites), therefore, we first determined that the residual binding of [3H]spiperone (approximately 20%) was inhibited by serotonergic agonists much more effectively than dopamine or noradrenaline, thus identifying the serotonergic component of [3H]spiperone binding. Thus, dopamine (or ADTN) inhibited the binding of [3H]spiperone at a high-affinity site (with dissociation constant of 10 nM dopamine), at a low-affinity site (with dissociation constant of 2,000 nM dopamine), and at the serotonergic site (with dissociation constant of 50,000 nM dopamine). In the absence of sodium ions, the high-affinity site was about 50% occupied by [3H]spiperone, and guanine nucleotide had no effect on this proportion. In the presence of 120 mM NaCl, however, the high-affinity site was reduced to 15% and guanine nucleotide completely eliminated this high-affinity site, 100% of the sites having been completely converted to their low-affinity state. Using [3H]N-propyl-norapomorphine to label the high-affinity state of the dopamine receptor, 50% conversion into the low-affinity state occurred at 45 mM LiCl, 69 mM NaCl, and 202 mM KCl. We conclude that it is possible to convert brain D2 dopamine receptors completely into their low-affinity state, in the presence of NaCl and a guanine nucleotide, providing that appropriate allowance is made for the serotonergic component of [3H]spiperone binding. 相似文献
172.
Comparative Histochemical and Biochemical Analysis of Endogenous Receptors for Glycoproteins in Human and Pig Peripheral Nerve 总被引:2,自引:2,他引:0
Hans-J. Gabius Beatrix Kohnke Thea Hellmann Thomas Dimitri Attila Bardosi 《Journal of neurochemistry》1988,51(3):756-763
Endogenous sugar-binding proteins were localized in sections of human and pig peripheral nerves by the application of two types of labelled ligands: neoglycoproteins (chemically glycosylated carrier proteins that had proven to be histochemically inert) and desialylated, naturally occurring glycoproteins. These proteins allowed evaluation of the presence and distribution of endogenous receptors for carbohydrates, commonly present in cellular glycoconjugates. (Neo)glycoprotein binding was similar, but not identical, for the two types of mammalian peripheral nerves. The pig nerve differed from the human nerve in more pronounced staining when using different types of beta-galactoside-terminated (neo)glycoproteins and charge-carrying neoglycoproteins, such as bovine serum albumin, bearing galactose-6-phosphate residues, glucuronic acid residues, and sialic acid residues. Comparative biochemical analysis of certain classes of sugar receptors by affinity chromatography and gel electrophoresis revealed the presence of sugar receptors that can contribute to the histochemical staining in a pattern with certain significant differences among rather similar expression for the two species. The assessment of sugar receptor distribution by application of (neo)glycoprotein binding among morphologically defined regions in nerves may hold promise in detecting developmental regulation and changes during nerve degeneration and subsequent regeneration after trauma or pathological states. Correlation of these results to changes in the structure and abundance of glycoconjugates, which are the potential physiological ligands of endogenous sugar receptors commonly detected by plant lectins, may help to infer functional relationships. 相似文献
173.
Dr. Caterina De Vinci Giancarlo Pizza Diego Cuzzocrea Domenico Menniti Ernesto Aiello Paolo Maver Giuseppe Corrado Piero Romagnoli Ennio Dragoni Giuseppe LoConte Umberto Riolo Massimo Masi Giuseppe Severini Vittorio Fornarola Dimitri Viza 《Biotherapy》1996,9(1-3):133-138
Results of conventional treatment of female non-bacterial recurrent cystitis (NBRC) are discouraging. Most patients show an
unexpected high incidence of vaginal candidiasis, while their cell mediated immunity to Herpes simplex viruses (HSV) and Candida
antigens seems impaired, and it is known that the persistence of mucocutaneous chronic candidiasis is mainly due to a selective
defect of CMI to Canadida antigens.
Twenty nine women suffering of NBRC, and in whom previous treatment with antibiotics and non-steroid anti-inflammatory drugs
was unsuccessful, underwent oral transfer factor (TF) therapy. TF specific to Canadida and/or to HSV was administered bi-weekly
for the first 2 weeks, and then once a week for the following 6 months. No side effects were observed during treatment. The
total observation period of our cohort was 24379 days with 353 episodes of cystitis recorded and a cumulative relapse index
(RI) of 43. The observation period during and after treatment was 13920 days with 108 relapses and a cumulative RI of 23 (P
< 0.0001). It, thus, seems that specific TF may be capable of controlling NBRC and alleviate the symptoms. 相似文献
174.
Professor Enzo Raise Luca Guerra Dimitri Viza Giancarlo Pizza Caterina De Vinci Maria Luisa Schiattone Leonarda Rocaccio Maria Cicognani Francesco Gritti 《Biotherapy》1996,9(1-3):49-54
The efficiency of HIV-1 specific transfer factor (TF) administration, combined with Zidovudine (ZDV), in asymptomatic persistent generalised lymphadenopaty, or AIDS related complex (ARC) patients was evaluated. Twenty patients were randomly assigned to receive only ZDV (1st group) or ZDV together with HIV-1-specific TF (2nd group). HIV-1-specific TF was administered orally at 2 × 107 cell equivalent daily for 15 days, and thereafter once a week for up to 6 months. There were no significant differences between the two groups in clinical evolution, red blood cells, haemoglobin, lymphocytes, CD20 subset, transaminases,β-2-microglobulin, p24 antigen. White blood cells, CD8 lymphocytes as well as IL-2 levels increased in the second group, while the CD4 subset increased in the first group. The combination treatment with ZDV and TF appeared to be safe and well tolerated. Furthermore, levels of serum cytokines were investigated in 10 patients (8 asymptomatic and 2 ARC) treated with ZDV, and compared with 5 patients of the 2nd group (3 asymptomatic and 2 ARC) treated with ZDV plus HIV-1-specific TF. Peripheral lymphocytes, CD4, CD8 subsets, IL-2, TNFα, IL-6, p24 antigen, IL-2 soluble lymphocyte receptors (sR), CD4sR, CD8sR and ß-2-microglobulin were evaluated at the baseline and at the 3rd month. The CD4 subset was not significantly different in the two groups, whilst IL-2 increased in the 2nd group receiving ZDV plus TF, suggesting an activation of the Th1 secretion pattern. 相似文献
175.
The ontogeny of the axial skeleton, in particular the caudal skeleton, is described from embryos to adult specimens in common wolffish, Anarhichas lupus. The eggs were incubated at constant temperatures of 7.0, 11.0 and 13.0 °C. High egg mortality and structural changes in skeletal development (fusion of parts, absence of distal radials and most of dorsal and anal fin rays, abnormal neural arches and dorsal fin rays) were observed at 13 °C. The frequencies of some anomalies were lower at 11 °C than at 13 °C. The main reason of structural changes of the skeleton at high temperature is the breaking of normal correlations between developmental rates of some cartilaginous structures and other tissues and organs of the embryo. These data suggest an epigenetic mechanism of skeletal evolution. 相似文献
176.
Dimitri Tsintjilonis 《The journal of the Royal Anthropological Institute》2004,10(2):375-393
Based on fieldwork among the Sa'dan Toraja of Indonesia, this article examines a specific relationship between the living and the dead. It is a relationship which is usually described in terms of intimacy. Within this intimacy, the living and the dead are described as sharing the same desires. Furthermore, as far as the living are concerned, these desires have to be expressed in words and acted out in the form of mortuary sacrifices. In this way, the living are said to remember the dead. My discussion focuses on the implications of this memory. 相似文献
177.
The crystal structure of Clostridium perfringens SleM,a muramidase involved in cortical hydrolysis during spore germination
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Bahja Al‐Riyami Fatma Işık Üstok Katherine Stott Dimitri Y. Chirgadze Graham Christie 《Proteins》2016,84(11):1681-1689
Clostridium perfringens spores employ two peptidoglycan lysins to degrade the spore cortex during germination. SleC initiates cortex hydrolysis to generate cortical fragments that are degraded further by the muramidase SleM. Here, we present the crystal structure of the C. perfringens S40 SleM protein at 1.8 Å. SleM comprises an N‐terminal catalytic domain that adopts an irregular α/β‐barrel fold that is common to GH25 family lysozymes, plus a C‐terminal fibronectin type III domain. The latter is involved in forming the SleM dimer that is evident in both the crystal structure and in solution. A truncated form of SleM that lacks the FnIII domain shows reduced activity against spore sacculi indicating that this domain may have a role in facilitating the position of substrate with respect to the enzyme's active site. Proteins 2016; 84:1681–1689. © 2016 Wiley Periodicals, Inc. 相似文献
178.
Stability strengths and weaknesses in protein structures detected by statistical potentials: Application to bovine seminal ribonuclease
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We present an in silico method to estimate the contribution of each residue in a protein to its overall stability using three database‐derived statistical potentials that are based on inter‐residue distances, backbone torsion angles and solvent accessibility, respectively. Residues that contribute very unfavorably to the folding free energy are defined as stability weaknesses, whereas residues that show a highly stabilizing contribution are called stability strengths. Strengths and/or weaknesses on residues that are in spatial contact are clustered into 3‐dimensional (3D) stability patches. The identification and analysis of strength‐ and weakness‐containing regions in a protein may reveal structural or functional characteristics, and/or interesting spots to introduce mutations. To illustrate the power of our method, we apply it to bovine seminal ribonuclease. This enzyme catalyzes the degradation of RNA strands, and has the peculiarity of undergoing 3D domain swapping in physiological conditions. The weaknesses and strengths were compared among the monomeric, dimeric and swapped dimeric forms. We identified weaknesses among the catalytic residues and a mixture of weaknesses and strengths among the substrate‐binding residues in the three forms. In the regions involved in 3D swapping, we observed an accumulation of weaknesses in the monomer, which disappear in the dimer and especially in the swapped dimer. Moreover, monomeric homologous proteins were found to exhibit less weaknesses in these regions, whereas mutants known to favor unswapped dimerization appear stabilized in this form. Our method has several perspectives for functional annotation, rational prediction of targeted mutations, and mapping of stability changes upon conformational rearrangements. Proteins 2016; 84:143–158. © 2015 Wiley Periodicals, Inc. 相似文献
179.
Lentiviral expression of GAD67 and CCK promoter‐driven opsins to target interneurons in vitro and in vivo
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