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11.
Christof Brunner Hans Lassmann Thomas V. Waehneldt Jean-Marie Matthieu† Christopher Linington‡ 《Journal of neurochemistry》1989,52(1):296-304
In a light and electron microscopic immunocytochemical study we have examined the distribution of myelin basic protein (MBP), 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP), and myelin/oligodendroglial glycoprotein (MOG) within CNS myelin sheaths and oligodendrocytes of adult Sprague-Dawley rats. Ultrastructural immunocytochemistry allowed quantitative analysis of antigen density in different myelin and oligodendrocyte zones: MBP was detectable in high density over the whole myelin sheath, but not in regions of loops, somata, or the oligodendrocyte plasma membrane. CNP reactivity was highest at the myelin/axon interface, and found in lower concentration over the outer lamellae of myelin sheaths, at the cytoplasmic face of oligodendrocyte membranes, and throughout the compact myelin. MOG was preferentially detected at the extracellular surface of myelin sheaths and oligodendrocytes and in only low amounts in the lamellae of compacted myelin and the myelin/axon border zone. Our studies, thus, indicate further the presence of different molecular domains in compact myelin, which may be functionally relevant for the integrity and maintenance of the myelin sheath. 相似文献
12.
Robert de Jonge Mario Bedu Nicole Fellmann Stephen Blonc Hilde Spielvogel Jean Coudert 《European journal of applied physiology and occupational physiology》1996,74(4):367-374
We have previously observed that 11-year-old children of low socio-economic status (LSES) showed a delayed physical growth of approximately 2 years and developed lower normalized short-term power output than children of high socio-economic status (HSES) of the same age. In contrast, maximal oxygen uptake
per unit of fat free mass was no different in either group. The aim of this study was to evaluate the effect of anthropometric characteristics between HSES and LSES prepubertal children in aerobic and anaerobic performance. To compare children of the same body dimensions, 11-year-old boys (n = 30) and girls (n = 31) of LSES and 9-year-old boys (n = 21) and girls (n = 27) of HSES were studied. Anthropometric measurements,
(direct test), maximal anaerobic power (P
max, force-velocity test) and mean anaerobic power (
, Wingate test) were determined. In these children having the same body dimensions: mean
were the same in LSES and HSES children [1.2 (SD 0.2)1-min–1];P
max and
were lower in LSES subjects [154.0 (SD 33.2) vs 174.6 (SD 38.4) W and 116.3 (SD 23.3) vs 128.2 (SD 28.0) W, respectively]; the linear relationships between
and fat free mass were the same in LSES and HSES boys but, in the girls, the LSES group had lower values. For anaerobic performance, the relationships were significantly different: the slopes were the same but LSES values for the both sexes were lower. These results would suggest that factors other than differences in body dimensions alone were responsible for the lower performance of LSES girls and boys. Cultural factors and motor learning, structural and functional alterations of muscle induced by marginal malnutrition have been discussed. 相似文献
13.
G. Falgairette M. Bedu N. Fellmann H. Spielvogel E. Van Praagh P. Obert J. Coudert 《European journal of applied physiology and occupational physiology》1994,69(1):36-43
Field tests of running and laboratory tests were performed in La Paz [high altitude (HA), 3700 m] and in Clermont-Ferrand [low altitude (LA), 300 m] to investigate their validity at HA. Prepubertal boys of mean ages 10.6 years (HA1,n = 16; LA1,n = 28) and pubertal boys of 13.7 years (HA2,n = 12; LA2,n = 41) took part in the study. All the boys performed a 30-m sprint (v
30m), a 30-s shuttle run (v
3os) and a progressive shuttle run test until their maximal aerobic velocity (v
maxsRT). Maximal oxygen consumption was extrapolated from the last test.
. In the laboratory, the boys performed a force-velocity test (P
max), a Wingate test (P
Wing) and a graded test to measure maximal oxygen consumption
; direct method) on a cycle ergometer. At similar ages, there was no significant difference between HA and LA boys forv
30m andP
max. Thev
30s of HA boys was 3%–4% lower than those of LA boys (P<0.05); there was no significant difference forP
Wing. Significant relationships were observed at both altitudes betweenP
max (watts per kilogram) andv
30m (HA:r=0.76; LA:r=0.84) and betweenP
Wing andv
30s (HA:r=0.67; LA:r = 0.77); the slopes and the origins were the same at HA and LA. The
,v
maxSRT and
were lower by 9%, 12% and 20%, respectively, at HA than at LA (P<0.05). However, the relationships between
and
(litres per minute) at HA (r=0.88) and at LA (r=0.93) were identical. In conclusion, chronic hypoxia did not modify performance in very short dash exercises. The influence of HA appeared when the exercise duration increased and, during a maximal shuttle run test, performance was reduced by 10% at HA. Moreover, it was possible to assessP
max,P
Wing and
at HA as well as at LA from field tests. 相似文献
14.
Yosepha Shahak Christof Klughammer Ulrich Schreiber Etana Padan Inge Herrman Günter Hauska 《Photosynthesis research》1994,39(2):175-181
The reduction by sulfide of exogenous ubiquinone is compared to the reduction of cytochromes in chromatophores of Rhodobacter capsulatus. From titrations with sulfide values for Vmax of 300 and 10 moles reduced/mg bacteriochlorophyll a·h, and for Km of 5 and 3 M were estimated, for decyl-ubiquinone-and cytochrome c-reduction, respectively. Both reactions are sensitive to KCN, as has been found for sulfide-quinone reductase (SQR) in Oscillatoria limnetica, which is a flavoprotein. Effects of inhibitors interfering with quinone binding sites suggest that at least part of the electron transport from sulfide in R. capsulatus employs the cytochrome bc
1-complex via the ubiquinone pool.Abbreviations BChl a
bacteriochlorophyll a
- DAD
diaminodurene
- decyl-UQ
decyl-ubiquinone
- LED
light emitting diode
- NQNO
2-n-nonyl-4-hydroxyquinoline-N-oxide
- PQ-1
plastoquinone 1
- SQR
sulfide-quinone reductase (E.C. 1.8.5.'.)
- UQ
ubiquinone 10
- Qc
the quinone reduction site on the cytochrome b
6
f/bc
1, complex (also termed Qi or Qr or Qn)
- Qs
the quinone reduction site on SQR
- Qz
quinol oxidation site on the b
6
f/bc
1, complex (also termed Qo or Qp) 相似文献
15.
Nathalie Leduc Victor Alejandro Iglesias Roland Bilang Andreas Gisel Ingo Potrykus Christof Sautter 《Sexual plant reproduction》1994,7(2):135-143
Direct gene transfer to floral meristems could contribute to cell-fate mapping, to the study of flower-specific genes and promoters, and to the production of transgenic gametes via the transformation of sporogenic tissues. Despite the wide potential of its applications, direct gene transfer to floral meristems has not been achieved so far because of the lack of suitable technology. We show in this paper that ballistic micro-targeting is the technique of choice for this purpose, and in this way, we were able to transfer genes efficiently into excised wheat immature spikes. Particle size was adjusted for optimal penetration into the L1 and L2 cell layers of the spikes with limited cell damage. Spikes at different developmental stages were shot either with a plasmid containing two genes involved in anthocyanin biosynthesis or with a plasmid bearing the uidA (-glucuronidase) gene. The transient expression of these marker genes was observed in the different developmental stages tested and in cells of both the L1 and the L2 layers. The transient expression of the uidA gene was significantly increased when the sucrose concentration in the culture medium was increased from 0.06 to 0.52 M. At the highest concentration, 100% of the targeted spikes expressed the uidA gene, with an average of 69 blue cells per spike. Twelve days after microtargeting, multicellular sectors showing transgene expression and containing up to 17 cells were found in 85% of the shot immature inflorescences. This indicated that targeted cells survived particle bombardment. Sectors were found in primordia of both vegetative and reproductive organs. 相似文献
16.
Eighteen German families with a history of paramyotonia congenita (PC) were characterised by genetic und mutational analysis at the SCN4A locus, which encodes the -subunit of the adult skeletal muscle sodium channel. We concentrated our analysis primarily on these families to test the hypothesis that a predominance of one common mutation occurs in all German PC families and that this mutation arose in a common ancestor originating in the North-West of the country. The present eighteen PC families exhibit two different mutations (R1448C and R1448H) on various SCN4A dinucleotide repeat haplotypes and therefore the majority of the mutations probably occurred independently. However, the R1448H mutation is extremely frequent in the North-West of Germany (Ravensberger Land) on a specific SCN4A microsatellite haplotype, indicating a founder effect within this subpopulation. Our results suggest that the R1448C/R1448H mutations are by far the most common to be associated with the PC phenotype in the German population.This paper is dedicated to Professor Dr. Dr. Peter Emil Becker on the occasion of this 85th birthday 相似文献
17.
Christof Sautter 《Plant Cell, Tissue and Organ Culture》1993,33(3):251-257
A gene transfer system for meristem cells was developed on the basis of a ballistic approach. In order to meet some important
prerequisites for an efficient transfer system, such as for example aiming at small tissues and control of penetration of
the microprojectiles, we developed an acceleration system fundamentally different from the usual macroprojectile driven approach.
Instead of a macroprojectile, microtargeting uses the law of Bernoulli for accleration of highly uniform-sized gold particles.
The system is able to deliver 80% of the particles to an area as small as 150 micron in diameter, which corresponds to the
size of a meristem. Microtargeting yields gene delivery (measured as number of transiently GUS expressing cells to up to 3%
of the cells exposed in the target area or up to 35 × 103 cells per cm2. Stable transformation of tobacco microcolonies with the microtargeting device was shown to have an efficiency up to one
stable transformant per 1000 cells exposed to the shot, or up to one transformant per shot. We perform 4 or 5 shots per min.
After 30 to 40 shots, reloading can take up to 2 min. Microtargeting is very flexible and allows for the adjustment of the
important parameters to fit the requirements of the respective tissue. 相似文献
18.
19.
This article presents for the first time a modified protocol for RNase protection analysis that allows the substitution of32P with33P without loss of the high sensitivity of this method achieved with32P. With this protocol, we were able to detect at least 1 pg of specific mRNA. In the RNase protection analysis33P labeled riboprobes are more advantageous with regard to an easier handling and better resolution. 相似文献
20.
Pigment analysis was performed by means of normal phase HPLC on a number of bacteriochlorophyll a and b containing species of purple bacteria that contain a core antenna only. At least 99% of the bacteriochlorophyll in Rhodobacter sphaeroides R26, Rhodopseudomonas viridis and Thiocapsa pfennigii was esterified with phytol (BChl a
p and BChl b
p, respectively). Rhodospirillum rubrum contained only BChl a esterified with geranyl-geraniol (BChl a
GG). Rhodospirillum sodomense and Rhodopseudomonas marina contained, in addition to BChl a
p, small amounts of BChl a
GG, and presumably also of BChl a esterified with dihydro and tetrahydro geranyl-geraniol (2,10,14-phytatrienol and probably 2,14-phytadienol). In all species bacteriopheophytin (BPhe) esterified with phytol was present. The BChl/BPhe ratio indicated that in these species a constant number of 25 ± 3 antenna BChls is present per reaction centre. This number supports a model in which the core antenna consists of 12 - heterodimers surrounding the reaction centre. Determination of the in vivo extinction coefficient of BChl in the core-reaction centre complex yielded a value of ca. 140 mM–1 cm–1 for BChl a containing species and of 130 mM–1 cm–1 for Rhodopseudomonas viridis.Abbreviations BChl
bacteriochlorophyll
- BPhe
bacteriopheophytin
- GG
geranyl-geraniol
- LHI and LHII
core and peripheral antenna complexes
- P
phytol
- RC
reaction centre
Dedicated to the memory of Professor D.I. Arnon. 相似文献