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11.
R Jurmain 《American journal of physical anthropology》1989,80(2):229-237
The well-known and extremely well-documented chimpanzees from Gombe National Park were analyzed for presence of skeletal pathologies. Of the 15 animals available for study, 11 were old and complete enough to permit systematic analysis. Of these, 10 showed some evidence of skeletal pathological involvement. The most common type of lesion seen resulted from trauma. Those chimps with the most fractures (Old Female, 3; Flo, 4; Hugo, 8) are consistently the oldest individuals in the sample. In addition to accidental falls, the most common cause of trauma was from interpersonal violence, resulting in bite wounds (see in two individuals) and fractures (see in three individuals). Conversely to trauma, degenerative disease was exceedingly rare in this population, found in no large intervertebral joints (N = 344) and only two major synovial joints (N = 186). In fact, the complete lack of osteophytosis, even in older individuals, stands in stark contrast to the situation seen in modern humans, perhaps in our species reflecting a biomechanical cost of bipedality. 相似文献
12.
Scott T. Sayers Hock C. Yeoh Jerry A. McLane Irene R. Held 《Neurochemical research》1988,13(12):1125-1131
The acetylcholine receptor (AChR) content and the autorphosphorylation of the regulatory subunit of cyclic AMP-dependent protein kinase type II (R-II) were evaluated in rat soleus muscles at 24, 30 and 66 hr after surgical denervation by cutting the nerve at a short distance (short-nerve-stump) and at a long distance (long-nerve-stump) from the muscle. AChR content was based on the specific binding of [125I]alpha-bungarotoxin (BUTX); changes in the autophosphorylation of R-II were based upon the predominant in vitro32P-phosphorylation of a 56-Kd soluble protein in cytosolic fractions of solei. The AChR content and the32P-autophosphorylation of R-II were increased in samples from short-nerve-stump solei, but not from long-nerve-stump solei, after a denervation-time of 30 hr. This nerve-stump-length dependency indicates that the two denervation effects are not related to the immediate halt of impulse-evoked muscle contractility. Furthermore, the results show that alterations in the32P-autophosphorylation of R-II occurred before, as well as whenever, increases in the AChR content were found. Speculatively, this temporal relationship may be significant with respect to the potential role of R-II in gene expression.Abbreviations ACh
acetylcholine
- AChR
acetylcholine receptor(s)
- BUTX
alpha-bungarotoxin
- Kd
kilodalton
- PAGE
polyacrylamide gel electrophoresis
- R-II
regulatory subunit of cyclic AMP-dependent protein kinase type II
- SDS
sodium dodecyl sulfate 相似文献
13.
A computerized mechanical cell stimulator for tissue culture: Effects on skeletal muscle organogenesis 总被引:8,自引:0,他引:8
Herman H. Vandenburgh 《In vitro cellular & developmental biology. Plant》1988,24(7):609-619
Summary A tissue culture system has been developed which can mechanically stimulate cells growing on a highly elastic plastic substratum
in a 24-well cell growth chamber. The collagen-coated substratum to which the cells attach and grow in the Mechanical Cell
Stimulator (Model I) can be repetitively stretched and relaxed by stepper motor with linear accuracy of 30 μm. The activity
controlling unit is an Apple IIe computer interfaced with the cell growth chamber via optical data links and is capable of
simulating many of the mechanical activity patterns that cells are subjected to in vivo. Primary avian skeletal myoblasts
proliferate and fuse into multinucleated myotubes in this set-up in a manner similar to normal tissue culture dishes. Under
static culture conditions, the muscle cells differentiate into networks of myotubes which show little orientation. Growing
the proliferating muscle cells on a unidirectional stretching substratum causes the developing myotubes to orient parallel
to the direction of movement. In contrast, growing the cells on a substratum undergoing continuous stretch-relaxation cycling
orients the developing myotubes perpendicular to the direction of movement. Neither type of mechanical activity significantly
affects the rate of cell proliferation of the rate of myoblast fusion into myotubes. These results indicate that during in
vivo skeletal muscle organogenesis, when substantial mechanical stresses are placed on skeletal muscle cells by both continuous
bone elongation and by spontaneous contractions, only bone elongation plays a significant role in proper fiber orientation
for subsequent functional work.
Supported by grants NS16753, AR36266, and RR05818 from the National Institutes of Health, Bethesda, MD. 相似文献
14.
The inside-out mode of the patch-clamp technique was used to study adenosine-5-triphosphate (ATP)-sensitive K+ channels in mammalian skeletal muscle. Vanadate, applied to the cytoplasmic face of excised patches, was a potent activator of ATP-sensitive K+ channels. Divalent cations (Mg2+, Ca2+) were a prerequisite for the activating process. The maximal effect was achieved using 1 mM vanadate dissolved in Ringer, increasing the open-state probability about ninefold. The active 5 + redox form of vanadate which stimulates ATP-sensitive K+ channels is likely to be decavanadate V10O
inf28
sup6–
. ATP concentration-response curves have Hill coefficients near three in internal Na+-rich Ringer and between one and two in internal KCl solutions. Half maximal channel blockage was observed at ATP concentrations of 4 and 8 M in Ringer and KCl solutions, respectively. Internal vanadate shifted the curves towards higher ATP concentrations without affecting their slopes. Thus 50% channel blockage occurred at 65 M ATP in internal Ringer containing 0.5 mM vanadate. The results indicate that the affinity and stoichiometry of ATP binding to ATP-sensitive K+ channels are strongly modulated by internal cations and that the ATP sensitivity is weakened by vanadate.
Offprint requests to: B. Neumcke 相似文献
15.
Functional morphology of the asterionic region in extant hominoids and fossil hominids 总被引:1,自引:0,他引:1
Asterionic sutural patterns in Plio-Pleistocene hominid crania have never been examined in detail. We present an analysis of this anatomical region in Australopithecus and Homo and relate different sutural patterns to functional changes in the masticatory apparatus. The great apes and A. afarensis share the common adult higher primate sutural pattern referred to as the "asterionic notch," which develops in response to the hypertrophy of posterior temporalis muscle fibers and the consequent formation of compound temporal/nuchal crests. This sutural configuration also appears to be present on the early Homo cranium KNM-ER 1805. In contrast, adult male A. boisei crania exhibit a unique pattern where the temporal squama overlaps the parietal which, in turn, overlaps the par mastoidea and the upper scale of the occipital bone. We relate this arrangement to the need to reinforce the rear of a thin-walled braincase against the net tensile forces exerted by the temporalis and nuchal muscles. The common juvenile hominoid edge-to-edge asterionic articulation is maintained in adult A. africanus, A. robustus, female A. boisei, and most Homo crania. We discuss the latter pattern in regard to anterior temporalis hypertrophy in A. africanus, A. robustus, and A. boisei and to craniofacial paedomorphosis in Homo. 相似文献
16.
Summary Distribution of glycogen particles in semithin and ultrathin sections of biopsy samples from human muscles subjected to either short- or long-term running were investigated using PAS and Periodic Acid-ThioSemiCarbazide-Silver Proteinate (PA-TSC-SP) staining methods. Glycogen particles were predominantly found immediately under the sarcolemma or aligned along the myofibrillar Iband. After long-term exhaustive exercise type-1 fibers with a few or no glycogen particles in the core of the fibers were frequently observed. The subsarcolemmal glycogen stores of these depleted type-1 fibers were about three times as large as after exhaustive short-time exercise. Another indication of utilization of subsarcolemmal glycogen stores during anaerobic exercise was that many particles displayed a pale, rudimentary shape. This observation suggests fragmental metabolization of glycogen. Thus, depending on type of exercise and type of fiber differential and sequential glycogen utilization patterns can be observed. 相似文献
17.
Two phosphoglucose isomerases (PGI) with different electrophoretic mobilities have been found in all groups of teleostean fishes studied, with the exception of the Clupeomorpha. PGI proved to be a good taxonomic criterion to differentiate members of the Nemipteridae, Sciaenidae, Platycephalidae and Stromateidae from the other teleost families. 相似文献
18.
G. H. Okker-Reitsma I. J. Dziadkowiec C. G. Groot 《In vitro cellular & developmental biology. Plant》1985,21(1):22-25
Summary A short method is described for obtaining a large number of pure vascular smooth muscle cells in culture. The smooth muscle
cells were isolated from human umbilical cord arteries digested twice by an enzyme mixture of collagenase, trypsin, elastase,
and DNAase with addition of α-tosyl-lysyl chloromethane. Primary cell culture and first subculture were not contaminated by
endothelial cells, no Factor VIII being produced. The cultures consisted of smooth muscle cells as appeared from phase contrast
and electron microscopy.
Part of this study was supported by a scholarship from the Dutch Ministry of Education and Science and by the Leyden University
Foundation. 相似文献
19.
Many studies have established a correlation of differences in the activities of various muscle types with differences in the expression of myosin isoforms. In this paper we report the sequence determination of myosin light chain-2 from rabbit slow skeletal (LC2s) and ventricular (LC2v) nmscles. We sequenced tryptic peptides from LC2v which account for all except a few terminal amino acid residues. The major part (87 residues) of the rabbit LC2s sequence, obtained from tryptic and cyanogen bromide (CNBr) peptides, was found to be identical to rabbit LC2v. Our results provide the first sequence information on LC2s from any species, and lend strong support to the hypothesis that LC2s and LC2v are identical. Comparisons of rabbit LC2v and LC2s with rabbit LC2f (from fast skeletal muscle), and also with chicken LC2f and LC2v, show clearly that LC2s and LC2v from mammalian and avian species are more closely related to each other than they are to LC2f isoforms from the same species. 相似文献
20.
V. Formicola 《Human Evolution》1986,1(6):557-563
Late Epigravettian postcranial human remains from the Arene Candide cave (Finale Ligure, Savona, Italy) were compared with
the Neolithic sample found in the upper levels of the same site. Data on length, diaphyseal circumference and diameter of
clavicle, humerus, radius, femur and tibia were collected from male specimens having all these bones. The Epigravettian sample
is characterized by significantly greater tibial length, robustness and platycnemia, significantly lower circumferences in
the upper limb bones and the clavicle, and a high degree of asymmetry. Variations observed in lower limb bones are those expected
on the basis of the different functional requirements of a hunting and gathering economy compared to a more sedentary, food
producing economy. Differences in the upper limb bones and the clavicle are less explicable. However, considering that in
spite of a more slender structure, the Epigravettian bones show evidence of vigorous use, variation in upper limb could result
from qualitatively different involvements. 相似文献