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91.
The overlapping distribution of opioid and cholecystokinin (CCK) peptides and their receptors (μ and δ opioid receptors; CCK-A
and CCK-B receptors) in the central nervous system have led to a large number of studies aimed at clarifying the functional
relationships between these two neuropeptides. Most of the pharmacological studies devoted to the role of CCK and enkephalins
have been focused on the control of pain. Recently the existence of regulatory mechanisms between both systems have been proposed,
and the physiological antagonism between CCK and endogenous opioid systems has been definitely demonstrated by coadministration
of CCK-B selective antagonists with RB 101, a systemically active inhibitor, which fully protects enkephalins from their degradation.
Several studies have also been done to investigate the functional relationships between both systems in development of opioid
side-effects and in behavioral responses. This article will review the experimental pharmacology of association of enkephalin-degrading
enzyme inhibitors and CCK-B antagonists to demonstrate the interest of these molecules in the management of both pain and
opioid addiction.
Special issue dedicated to Dr. Eric J. Simon. 相似文献
92.
Sylvie Leparoux Marc Padrines Yannick Fortun Bernard Colas 《Biotechnology letters》1996,18(2):135-138
Summary Enzymatic O-glycosylation of dipeptide derivatives containing a serine residue in the N or C terminal position and alanine or glycine as the second amino acid was achieved using the transgalactosylation activity of -galactosidase from the Achatina achatina digestive juice. Reactions were performed with lactose as glycosyl donor and the dipeptide ethyl (or methyl) esters N-protected by a benzyloxycarbonyl group (Z) as glycosyl acceptors. Yields of galactosyl-dipeptide derivatives were much higher than those obtained with the E.coli -galactosidase as catalyst. 相似文献
93.
Fatal attack on an infant by an adult female tonkean macaque 总被引:1,自引:0,他引:1
We describe a fatal attack on a 10-month-old female infant by an adult female Tonkean macaque (Macaca tonkeana)in a semi-free-ranging group. During an intense conflict involving many group members, an adult female, the second most dominant
in the group, attacked the infant of a lower-ranking female. The attacker remained near the victim for approximately 20 min,
grabbing and biting it repeatedly, until the mother retrieved the infant. She died 2 days later. An autopsy revealed no lethal
injury;the main cause of death was starvation or dehydration or both. We discuss social conditions under which a fatal attack by
an adult female might occur. 相似文献
94.
Bernard L. Strehler 《Photosynthesis research》1996,48(1-2):11-18
The circumstances that led to the discovery that plants luminesce after they are illuminated are described, as are other discoveries that would not have been possible were it not for the fortuitous association I had with my dear and most admirable friend, W.A. Arnold, to whom this special issue is dedicated. 相似文献
95.
Hanne Gahéry-Ségard Evelyne Jouvin-Marche Adrien Six Carine Gris-Liebe Marie Malissen Bernard Malissen Pierre-André Cazenave Patrice N. Marche 《Immunogenetics》1996,44(4):298-305
The number of mouse Tcra-V gene segments varies from one individual to another and is estimated to be about 100. Southern blot analysis revealed that
most of the Tcra-V are organized in clusters composed of copies of Tcra-V belonging to different subfamilies. We analyzed in detail a Tcra-V subfamily and looked for new Tcra-V in order to improve the knowledge of the mouse Tcra locus organization. A series of genomic clones derived from the B10.A mouse strain enclosing these clusters was used to determined
the structure of all the Tcra-V2. We were able to identify ten Tcra-V2. This study showed that the Tcra-V2 can be organized into three structural subgroups. The distribution of the genes along the Tcra locus, plus their structural organization, indicates that successive duplications occurred during the processes of expansion
and contraction of the Tcra-V gene subfamilies. Several Tcra-V2 are also identical, indicating recent duplications. The most divergent Tcra-V2 differ by 7.4% nucleotides, leading to 5.2% differences in amino acid contents.
Received: 8 August 1995 / Revised: 24 April 1996 相似文献
96.
Veronique Billat Jean C. Renoux Jacques Pinoteau Bernard Petit Jean P. Koralsztein 《European journal of applied physiology and occupational physiology》1994,69(3):271-273
The aim of this study was to measure running times to exhaustion (Tlim) on a treadmill at 100% of the minimum velocity which elicits
max
max in 38 elite male long - distance runners
max = 71.4 ± 5.5 ml.kg–1.min–1 and
max = 21.8 ± 1.2 km.h–1). The lactate threshold (LT) was defined as a starting point of accelerated lactate accumulation around 4 mM and was expressed in
max. Tlim value was negatively correlated with
max (r = -0.362, p< 0.05) and
max (r = –0.347, p< 0.05) but positively with LT (%v
max) (r = 0.378, p < 0.05). These data demonstrate that running time to exhaustion at
max in a homogeneous group of elite male long-distance runners was inversely related to
max and experimentally illustrates the model of Monod and Scherrer regarding the time limit-velocity relationship adapted from local exercise for running by Hughson et al. (1984) . 相似文献
97.
Spermiogenesis in M. herpestisbegins with the formation of a differentiation zone which contains two centrioles associated with an electron–dense, finely granular material. This granular material very quickly becomes striated, a median cytoplasmic extension forms, one of the centrioles becomes laterally oriented in a cytoplasmic bud and the other gives rise to a flagellum. After the migration of the nucleus, a helicoidal crested–like body forms, then the old spermatid separates from the residual cytoplasm. The mature M. herpestisspermatozoon exhibits an apical cone of electron–dense material, a crested–like body and cortical microtubules which are electron–dense centred and spiralized except at their posterior extremity where they are parallel to the spermatozoon axis. The axoneme is of the 9 + ‘1’ pattern. It reaches the posterior extremity of the gamete where the cytoplasm is very electron–dense. The presence of centrioles flanked by ‘striated roots’ has never, to our knowledge, been reported in a platyhelminth. Likewise, a nucleus with an annular cross–section and unevenly distributed electron–dense peri–axonemal material has never been described in a cestod. 相似文献
98.
Michael Dean J. Claiborne Stephens Cheryl Winkler Deborah A. Lomb Mark Ramsburg Raleigh Boaze Claudia Stewart Lauren Charbonneau David Goldman Bernard J. Albaugh James J. Goedert R. Palmer Beasley Lu-Yu Hwang Susan Buchbinder Michael Weedon Patricia A. Johnson Mary Eichelberger Stephen J. O'Brien 《American journal of human genetics》1994,55(4):788-808
A panel of 257 RFLP loci was selected on the basis of high heterozygosity in Caucasian DNA surveys and equivalent spacing throughout the human genome. Probes from each locus were used in a Southern blot survey of allele frequency distribution for four human ethnic groups: Caucasian, African American, Asian (Chinese), and American Indian (Cheyenne). Nearly all RFLP loci were polymorphic in each group, albeit with a broad range of differing allele frequencies (δ). The distribution of frequency differences (δ values) was used for three purposes: (1) to provide estimates for genetic distance (differentiation) among these ethnic groups, (2) to revisit with a large data set the proportion of human genetic variation attributable to differentiation within ethnic groups, and (3) to identify loci with high δ values between recently admixed populations of use in mapping by admixture linkage disequilibrium (MALD). Although most markers display significant allele frequency differences between ethnic groups, the overall genetic distances between ethnic groups were small (.066–.098), and <10% of the measured overall molecular genetic diversity in these human samples can be attributed to “racial” differentiation. The median δ values for pairwise comparisons between groups fell between .15 and .20, permitting identification of highly informative RFLP loci for MALD disease association studies. 相似文献
99.
Indigenous Arbuscular Mycorrhizal Fungi Associated with Acacia albida Del. in Different Areas of Senegal 下载免费PDF全文
Tahir A. Diop Mamadou Gueye Bernard L. Dreyfus Christian Plenchette Desire G. Strullu 《Applied microbiology》1994,60(9):3433-3436
The influences of seasons, plant age, and physicochemical properties of the soil on surface and deep biological arbuscular mycorrhizal fungus parameters associated with Acacia albida were assessed in different areas of Senegal. More indigenous arbuscular mycorrhizal propagules were found in the localities of the Sudano-Guinean zone (Djinaki and Kabrousse) than in those of the Sahelian zone (Louga and Diokoul), and species belonging to the genera Glomus, Gigaspora, Acaulospora, and Sclerocystis prevailed. The numbers of total and viable spores increased more during the rainy season than during the dry season (about 108% more total spores and 262% more viable spores). Similarly, both total and viable spores were more prevalent around young Acacia trees than old trees. However, the intensities of root colonization did not differ in each ecoclimatic zone. 相似文献
100.
Catherine L. Craig Gary D. Bernard Jonathan A. Coddington 《Evolution; international journal of organic evolution》1994,48(2):287-296
We measured the reflectance properties of unpigmented silks spun by a systematic array of primitive (Deinopoidea) and derived (Araneoidea) aerial, web-spinning spiders, as well as silks spun by Araneomorphae and Mygalomorphae spiders that do not spin aerial webs. Our data show that all of the primitive aerial web spinners produce catching silks with a spectral peak in the ultraviolet (UV), and cladistic analysis suggests that high UV reflection is the primitive character state for silk spectral properties. In contrast, all of the derived aerial web spinners produce silks that are spectrally flat or characterized by reduced reflectance in the UV. Correlated with the evolution of these catching silks is a 37-fold increase in species number and apparent habitat expansion. This suggests that the unique silk proteins spun by the araneoids have been important to their ecological and evolutionary diversity. 相似文献