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51.
Véronique Blanchard Muriel Chritin Sheela Vyas Marc Savasta Claude Feuerstein Yves Agid France Javoy-Agid Rita Raisman-Vozari 《Journal of neurochemistry》1995,64(4):1669-1679
Abstract: The present study was undertaken to examine the adaptive changes occurring 1 and 6 months after moderate or severe unilateral 6-hydroxydopamine-induced lesions confined to the lateral part of the rat substantia nigra pars compacta (SNC). The expression of tyrosine hydroxylase (TH) enzyme was analyzed in the remaining dopaminergic nigral cell bodies and in the corresponding striatal nerve endings. In the cell bodies of the lesioned SNC, TH mRNA content was increased (+20 to +30%) 6 months after the lesion without changes in cellular TH protein amounts. The depletion of TH protein in the nerve terminal area was less severe than the percentage of cell loss observed in the SNC at 1- and 6-month postlesion intervals. Moreover, the decrease in TH protein in the ipsilateral striatum was less pronounced 6 months after lesion than 1 month after. That no corresponding change in TH protein content was observed in the cell bodies at a time when TH increased in nerve terminals suggests that the newly synthesized protein is probably rapidly transported to the striatal fibers. These results suggest the existence of a sequence of changes in TH expression between cell bodies and fibers, occurring spontaneously after partial denervation of the nigrostriatal pathway. 相似文献
52.
Erwin Blum Beatrice Py Agamemnon J. Carpousis & Christopher F. Higgins 《Molecular microbiology》1997,26(2):387-398
Xer site-specific recombination functions in the stable inheritance of circular plasmids and bacterial chromosomes. Two related recombinases, XerC and XerD, mediate this recombination, which 'undoes' the potential damage of homologous recombination. Xer recombination on natural plasmid sites is preferentially intramolecular, converting plasmid multimers to monomers. In contrast, recombination at the Escherichia coli recombination site, dif , occurs both intermolecularly and intramolecularly, at least when dif is inserted into a multicopy plasmid. Here the DNA sequence features of a family of core recombination sites in which the XerC- and XerD-binding sites, which are separated by 6 bp, were analysed in order to ascertain what determines whether recombination will be preferentially intramolecular, or will occur both within and between molecules. Sequence changes in either the XerC- or XerD-binding site can alter the recombination outcome. Preferential intramolecular recombination between a pair of recombination sites requires additional accessory DNA sequences and accessory recombination proteins and is correlated with reduced affinities of recombinase binding to recombination core sites, reduced XerC-mediated cleavage in vitro , and an apparent increased overall bending in recombinase–core-site complexes. 相似文献
53.
Pickering Gisele P.; Fellmann Nicole; Morio Beatrice; Ritz Patrick; Amonchot Aime; Vermorel Michel; Coudert Jean 《Journal of applied physiology》1997,83(4):1300-1306
Pickering, Gisèle P., Nicole Fellmann, BéatriceMorio, Patrick Ritz, Aimé Amonchot, Michel Vermorel, and JeanCoudert. Effects of endurance training on the cardiovascularsystem and water compartments in elderly subjects. J. Appl. Physiol. 83(4): 1300-1306, 1997.Theeffects of endurance training on the water compartments and thecardiovascular system were determined in 10 elderly subjects [age62 ± 2 yr, pretraining maximal oxygen consumption(O2 max)/kg = 25 ± 2 ml · min1 · kg1body wt]. They trained on a cycloergometer 3 times/wk for 16 wk(50-80%O2 max,then 80-85%O2 max). They werechecked at 8 wk, 16 wk, and 4 mo after detraining. Training improvedO2 max (+16%) andinduced plasma volume expansion (+11%). No change in total body water,extracellular fluid, interstitial and intracellular fluid volumes,fat-free mass, and body weight was detected in this small sample withtraining. Body fat mass decreased (2.1 ± 2.2 kg).Echocardiography at rest showed increased fractional shortening andejection fraction and decreased left ventricular end-systolic dimension(P < 0.05). Blood volume expansioncorrelates with cardiac contractility and has an impact on cardiacfunction. These improvements are precarious, however, and arecompletely lost after 4 mo of detraining, when elderly subjects losethe constraints and the social stimulation of the imposed protocol. 相似文献
54.
A novel chromatin-forming histone H1 homologue is encoded by a dispensable and growth-regulated gene in Bordetella pertussis 总被引:5,自引:1,他引:4
55.
Dr. Edward B. Blanchard Guy C. McCoy Frank Andrasik Maryrose Acerra Thomas P. Pallmeyer Robert Gerardi Mindy Halpern Alison Musso 《Applied psychophysiology and biofeedback》1984,9(4):471-495
In a controlled trial, thermal biofeedback (n=20) and abbreviated progressive relaxation (n=22) were compared in the treatment of mild to moderate hypertensive patients whose blood pressures (BP) were initially controlled on two medications. For the clinical end point of maintaining control of BP on a single drug after treatment, biofeedback was superior to relaxation training (at 3 months, 47% success for biofeedback versus 23% for relaxation). This same result tended to be true for patient-measured home BPs. BPs from laboratory psychophysiological testing showed no consistent advantage for one treatment over the other.This research was supported by a grant from NHLB1, HL-27622. 相似文献
56.
57.
The effect of the protein structure of ( on its incorporation into liposome membranes was investigated as follows: the catalytic α-subunit of ( was split into low-molecular weight fragments by trypsin treatment and the digested enzyme was reconstituted at the same protein concentration as intact control enzyme. The reconstitution process was quantified by the average number of intramembrane particles appearing on concave and convex fracture faces after freeze-fracture of the ( liposomes. The number of intramembrane particles as well as their distribution on concave and convex fracture faces is not modified by the proteolysis. In contrast, the ATPase activity and the transport capacity of the ( decrease progessively with increasing incubation times in the presence of trypsin and are abolished when the original 100 000 molecular weight α-subunit is no longer visible by sodium dodecylsulfate gel electrophoresis. Apparently, functional ( with intact protein structure and digested, non functional enzyme consisting of fragments of the α-subunit reconstitute in the same manner and to the same extent as judged by freeze-fracture analysis. We conclude that, while trypsin treatment modifies the ( molecule in a functional sense, it appears not to modify its interaction with the bilayer in producing intramembrane particles. On the basis of our results, we propose a lipid-lipid interaction mechanism for reconstitution of (. 相似文献
58.
Jiann-Shin Chen D.K. Blanchard 《Biochemical and biophysical research communications》1984,122(1):9-16
Clostridium pasteurianum has two distinct hydrogenases, the bidirectional hydrogenase and the H2-oxidizing (uptake) hydrogenase. The H2-oxidizing hydrogenase has been purified (up to 970-fold) to a specific activity of 17,600 μmol H2 oxidized/min·mg protein (5 mM methylene blue) or 3.5 μmol H2 produced/min·mg protein (1 mM methyl viologen). The uptake hydrogenase has a Mr of 53,000 (one polypeptide chain). Depending upon how protein was measured, the Fe and S= contents (gatom/mol) were 4.7 and 5.2 (by the dye-binding assay) or 7.2 and 8.0 (by the Lowry method). Both reduced and oxidized forms of the enzyme gave electron paramagnetic resonance signals. The activation energy for H2-production and H2-oxidation by the uptake hydrogenase was 59.1 and 31.2 kJ/mol, respectively. In the exponential phase of growth, the ratio of uptake hydrogenase/bidirectional hydrogenase in NH3-grown cells was much lower than that in N2-fixing cells. 相似文献
59.
Attack and defensive behaviour in the albino rat 总被引:3,自引:0,他引:3
Attack of dominant colony males of an albino rat (Rattus norvegicus) strain, on introduced strangers, produced a non-random distribution of bites, with ventral trunk virtually never bitten. Also, vibrissae-contact of attacker and defender interfered with bites to the defender's head and upper back. The specific agonistic reactions of attacking and defending rats appeared to involve strategies based on these limitation on attack: defenders utilized 'boxing' and lying 'on-the-back' behaviour, which interposed ventral trunk and vibrissae between attacker and defender. In turn, the 'lateral display' permitted attackers to circumvent the defender's behaviour. Limitations on attack therefore appeared to underlie the specific agonistic behaviour of both attacking and defending rats. 相似文献
60.
The association of [3H] [D-Ala2, D-Leu5] enkephalin ([3H]DADLE]) with mouse neuroblastoma cells (N4TG1) was investigated. Under identical conditions the time course, dose response curve and temperature dependence for ligand uptake were similar to those for ligand-induced receptor loss (down regulation). Uptake of [3H]DADLE was inhibited by opiate ligands as well as by the metabolic inhibitors sodium azide and 2,4 dinitrophenol. Comparison of the effects of these inhibitors on receptor binding, ligand uptake and receptor loss indicated that these cells accumulate [3H]DADLE in excess of their surface receptor number. The data suggest that receptor recycling occurs and that ligand is internalized via receptor mediated endocytosis. 相似文献