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35.
Antonio J. Ferreira 《The Western journal of medicine》1961,94(6):369-377
The causes and the nature of the psychiatric disorder labeled schizophrenia remain vexingly obscure. Perhaps as an expression of a still extant body-mind controversy, most of the experiments and statements made toward an elucidation of the problem follow one or the other of two opposing postulations: (a) That its origin is genetico-organic; (b) that it is environmental. In a review of the outstanding “facts” for either argument, it is notable that they presuppose not only a difference in theoretical frameworks, but two radically distinct outlooks. This is reflected in therapy, a field in which organicists and environmentalists stand even further apart; the organicist, relying heavily on electroshock and drugs, hopes to counteract a hypothetical body malfunction, and the environmentalist, through psychotherapy, attempts to make it possible for the patient to disentangle his own conflicting feelings and reaction patterns.Between the two an eclectic position seems hardly tenable. For, in spite of voluminous research and speculation, it has not been possible to build a bridge between the two camps and integrate different outlooks which, at times, have brought psychiatry almost to the point of schism. 相似文献
36.
Inhibition of lipolysis by hydrocarbons and fatty alcohols 总被引:2,自引:0,他引:2
The hydrolysis of long-chain triglyceride by pancreatic lipase (EC 3.1.1.3) is inhibited by hydrophobic solutes that are dissolved in the fat. Solutes tested included n-alkanes (C10-C16), aromatic and chlorinated aromatic hydrocarbons (including a PCB and DDT), n-alcohols (C10-C16), and cholesterol. Except for cholesterol, which stimulated lipolysis at low concentrations, all compounds produced roughly similar inhibition curves that followed the pattern of a typical Langmuir adsorption isotherm (Mattson, F. H., R. A. Volpenhein, and L. Benjamin, 1970. J. Biol. Chem. 245: 5335-5340). According to this interpretation, hydrophobic solutes dissolved within fat droplets partition between the interior oil phase and the surface monolayer where lipolysis occurs. Although the aromatic and chlorinated aromatic hydrocarbons were approximately 25% more inhibitory than the long-chain aliphatic hydrocarbons, as a single class, hydrocarbons were 7-10 times weaker inhibitors of lipolysis than fatty alcohols. In contrast to the alcohols whose inhibitory action may involve several mechanisms, the hydrocarbons behaved like simple dilution inhibitors; i.e., at 50% inhibition the mass ratio of hexadecane to triglyceride was 0.42. The lack of a chain length effect indicates that the hydrocarbons are not adsorbed at the interface but interdigitate the triglyceride molecules and align parallel to the lipid acyl chains. Inhibition by hydrophobic solutes was not reversed by the presence of 4 mM taurodeoxycholate and pancreatic procolipase or colipase. 相似文献
37.
Identification of a common molecular basis for combined 17α-hydroxylase/17,20-lyase deficiency in two Mennonite families 总被引:1,自引:0,他引:1
Keiko Kagimoto Michael R. Waterman Masaaki Kagimoto P. Ferreira Evan R. Simpson Jeremy S. D. Winter 《Human genetics》1989,82(3):285-286
Summary During the course of studies to characterize mutations of the CYP17 gene that cause the 17-hydroxylase-deficient form of congenital adrenal hyperplasia we have discovered two ostensibly unrelated Mennonite families in which affected individuals are homozygous for the same mutation. The defect is a four-base duplication in exon 8 of the CYP17 gene, which alters the reading frame encoding the C-terminal 26 animo acids of cytochrome P45017. 相似文献
38.
Stephen Francis Ferrari Maria Aparecida Lopes Ferrari 《Primates; journal of primatology》1990,31(3):323-338
The predator avoidance behaviour of a free-ranging group of buffy-headed marmosets,Callithrix flaviceps, was recorded in detail during the course of a long-term study of behavioural ecology at the Fazenda Montes Claros, southeastern
Brazil. Four distinct patterns of predator avoidance behaviour, each with specific vocalisations, were recognised and are
described here. The selection and use of sleeping sites by the study group are also described. An analysis of the records
indicates that these small monkeys are generally most vulnerable to predation by aerial raptors. Variations in the frequency
of alarm calls also indicate that the marmosets tend to be more vigilant at higher levels in the forest and when the leaf
cover is less extensive. The implications of group size and social structure for both the evolution and the efficacy of the
anti-predator behaviour of marmosets are also discussed. 相似文献
39.
Roger F. Castilho Paulo C. Carvalho-Alves Anibal E. Vercesi Sérgio T. Ferreira 《Molecular and cellular biochemistry》1996,159(2):105-114
The major protein in the sarcoplasmic reticulum (SR) membrane is the Ca2+ transporting ATPase which carries out active Ca2+ pumping at the expense of ATP hydrolysis. The aim of this work was to elucidate the mechanisms by which oxidative stress induced by Fenton's reaction (Fe2+ + H2O2 HO· + OH–+ Fe3+) alters the function of SR. ATP hydrolysis by both SR vesicles (SRV) and purified ATPase was inhibited in a dose-dependent manner in the presence of 0–1.5 MM H2O2 plus 50 M Fe2+ and 6 mM ascorbate. Ca2+ uptake carried out by the Ca2+-ATPase in SRV was also inhibited in parallel. The inhibition of hydrolysis and Ca2+ uptake was not prevented by butylhydroxytoluene (BHT) at concentrations which significantly blocked formation of thiobarbituric acid-reactive substances (TBARS), suggesting that inhibition of the ATPase was not due to lipid peroxidation of the SR membrane. In addition, dithiothreitol (DTT) did not prevent inhibition of either ATPase activity or Ca2+ uptake, suggesting that inhibition was not related to oxidation of ATPase thiols. The passive efflux of 45Ca2+ from pre-loaded SR vesicles was greatly increased by oxidative stress and this effect could be only partially prevented (ca 20%) by addition of BHT or DTT. Trifluoperazine (which specifically binds to the Ca2+-ATPase, causing conformational changes in the enzyme) fully protected the ATPase activity against oxidative damage. These results suggest that the alterations in function observed upon oxidation of SRV are mainly due to direct effects on the Ca2+-ATPase. Electrophoretic analysis of oxidized Ca2+-ATPase revealed a decrease in intensity of the silver-stained 110 kDa Ca2+-ATPase band and the appearance of low molecular weight peptides (MW < 100 kDa) and high molecular weight protein aggregates. Presence of DTT during oxidation prevented the appearance of protein aggregates and caused a simultaneous increase in the amount of low molecular weight peptides. We propose that impairment of function of the Ca2+-pump may be related to aminoacid oxidation and fragmentation of the protein.Abbreviations AcP
acetylphosphate
- BHT
butylhydroxytoluene
- DTT
dithiothreitol
- Hepes
4-(2-hydroxyethyl)-1-piperazine-ethanesulfonic acid
- SDS
sodium dodecyl sulfate
- SDS-PAGE
polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate
- SR
sarcoplasmic reticulum
- SRV
sarcoplasmic reticulum vesicles
- TBA
thiobarbituric acid
- TBARS
thiobarbituric acid-reactive substances
- TFP
trifluoperazine 相似文献
40.
Applications of intrinsic fluorescence measurements in the study of Ca2+-transport ATPases are reviewed. Since the initial reports showing that the fluorescence emission was sensitive to Ca2+ binding, a substantial amount of work has focused on the use of both steady-state and time-resolved fluorescence spectroscopy to investigate structure-function relationships in sarcoplasmic reticulum and plasma membrane Ca2+-ATPases. These studies have revealed ligand-induced conformational changes, as well as provided information on protein-protein, protein-solvent and/or protein-lipid interactions in different functional states of these proteins. The main results of these studies, as well as possible future prospects are discussed. 相似文献