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131.
The most common bacterial species isolated from the vaginas of 37 healthy rhesus macaques were Streptococcus viridans, coagulase negative Staphylococcus, Mobiluncus curtisii ss. curtisii, Corynebacterium renale-like organisms, Peptostreptococcus anaerobius, Gardnerella-like organisms, and other Corynebacterium species. The vaginal flora of the rhesus macaque differs from that previously reported for five other primate species. A two-year retrospective review of clinical cases of vaginitis and metritis found Escherichia coli and coagulase positive Staphylococci to be the most common pathogens isolated.  相似文献   
132.
Two novel stereoisomeric tricyclic sesquiterpene ketones were isolated from Geranium macrorrhizum.  相似文献   
133.
Summary Spectrin forms aggregates in solution when incubated at relatively high concentrations (several millimolar) of divalent cations. According to the evidence of electron microscopy, aggregates of globular appearance and, rather uniform size are cooperatively formed from spectrin dimers, no intermediate structures being seen. Inter-dimer chemical cross-linking of spectrin in intact red cell membranes is enhanced if magnesium ions at a concentration of 0.5mm or more are present. On the other hand, the elimination of magnesium from the interior of intact cells causes no significant change in shear elastic modulus, measured by micropipette assays, nor is there any dependence of membrane filtration rate on intracellular free magnesium concentration in the range 0–1mm. Magnesium-depleted cells are, however, converted into echinocytes within a short period, in which, control cells, exposed to ionophore and external magnesium ions, remain completely discoid. Magnesium-depleted cells also undergo structural, changes on heating below the temperature at which vesiculation sets in. These reveal themselves by the transformation of the cells to a unique characteristic shape, by grossly reduced filtrability, and by extensive agglutination of the cells when treated with a bifunctional reagent. Magnesium ions thus regulate the stability, but not to any measurable extent the gross elasticity, of the red cell membrane.  相似文献   
134.
Summary The genetic distances among primate lineages estimated from orthologous noncoding nucleotide sequences of -type globin loci and their flanking and intergenic DNA agree closely with the distances (delta T50H values) estimated by cross hybridization of total genomic single-copy DNAs. These DNA distances and the maximum parsimony tree constructed for the nucleotide sequence orthologues depict a branching pattern of primate lineages that is essentially congruent with the picture from phylogenetic analyses of morphological characters. The molecular evidence, however, resolves ambiguities in the morphological picture and provides an objective view of the cladistic position of humans among the primates. The molecular data group humans with chimpanzees in subtribe Hominina, with gorillas in tribe Hominini, orangutans in subfamily Homininae, gibbons in family Hominidae, Old World monkeys in infraorder Catarrhini, New World monkeys in semisuborder Anthropoidea, tarsiers in suborder Haplorhini, and strepsirhines (lemuriforms and lorisiforms) in order Primates. A seeming incongruency between organismal and molecular levels of evolution, namely that morphological evolution appears to have speeded up in higher primates, especially in the lineage to humans, while molecular evolution has slowed down, may have the trivial explanation that relatively small genetic changes may sometimes result in marked phenotypic changes.  相似文献   
135.
Summary The DNA base sequences of the entire chimpanzee 1 globin gene and an additional 1 kb of DNA flanking both the human and chimpanzee genes have been determined. Whereas the human 1 gene contains a termination codon in the sixth position, the chimpanzee gene appears to be functional. This finding confirms Proudfoot et al.'s suggestion that the human 1 gene was recently inactivated. Like the corresponding human 1 and 2 genes, the first and second introns of the chimpanzee 1 gene are occupied largely by tandem repeats of short oligonucleotides. These tandem repeats have undergone several rearrangements since the divergence of the human and chimpanzee 1 genes.  相似文献   
136.
The importance of arm-raising has been a major consideration in the functional interpretation of differences in shoulder morphology among species of nonhuman primates. Among the characters that have been associated with enhancement of the arm-raising mechanism in hominoid primates are the relative enlargement of cranial trapezius and caudal serratus anterior, as the main scapular rotators, as well as changes in scapular morphology associated with their improved leverage for scapular rotation. Yet in an EMG study of cranial trapezius and caudal serratus anterior function in the great apes, Tuttle and Basmajian (Yrbk. Phys. Anthropol. 20:491-497, 1977) found these muscles to be essentially inactive during arm-raising. Although Tuttle and Basmajian suggest that the cranial orientation of the glenoid fossa in apes has reduced the demand for scapular rotation during arm-raising, subsequent EMG studies on other primate species suggest that these muscles do play a significant role in arm motion during active locomotion. This paper presents a reexamination of muscle recruitment patterns for trapezius and caudal serratus anterior in the chimpanzee. All but the lowest parts of caudal serratus anterior were found to be highly active during arm-raising motions, justifying earlier morphological interpretations of differences in caudal serratus anterior development. The lowest digitations of this muscle, while inactive during arm-raising, displayed significant activity during suspensory postures and locomotion, presumably to control the tendency of the scapula to shift cranially relative to the rib cage. Cranial trapezius did not appear to be involved in arm-raising; instead, its recruitment was closely tied to head position.  相似文献   
137.
四川侏罗纪三列齿类头后骨骼   总被引:1,自引:1,他引:0  
本文记述了最晚期的三列齿类——似卞氏兽 (Bienotheroides) 的头后骨骼,并和其他三列齿类以及原始哺乳动物作了对比.肩胛骨上雏型岗上窝的出现,证明三列齿类与原始哺乳类的关系要比以往想象的更为密切.  相似文献   
138.
The objective of the current study was to investigate the mechanism by which the corpus luteum (CL) of the monkey undergoes desensitization to luteinizing hormone following exposure to increasing concentration of human chorionic gonadotrophin (hCG) as it occurs in pregnancy. Female bonnet monkeys were injected (im) increasing doses of hCG or dghCG beginning from day 6 or 12 of the luteal phase for either 10 or 4 or 2 days. The day of oestrogen surge was considered as day ‘0’ of luteal phase. Luteal cells obtained from CL of these animals were incubated with hCG (2 and 200 pg/ml) or dbcAMP (2.5,25 and 100 M) for 3h at 37°C and progesterone secreted was estimated. Corpora lutea of normal cycling monkeys on day 10/16/22 of the luteal phase were used as controls. In addition thein vivo response to CG and deglycosylated hCG (dghCG) was assessed by determining serum steroid profiles following their administration. hCG (from 15–90 IU) but not dghCG (15-90 IU) treatment in vivo significantly (P < 0.05) elevated serum progesterone and oestradiol levels. Serum progesterone, however, could not be maintained at a elevated level by continuous treatment with hCG (from day 6–15), the progesterone level declining beyond day 13 of luteal phase. Administering low doses of hCG (15-90 IU/day) from day 6–9 or high doses (600 IU/day) on days 8 and 9 of the luteal phase resulted in significant increase (about 10-fold over corresponding control P < 0.005) in the ability of luteal cells to synthesize progesterone (incubated controls) in vitro. The luteal cells of the treated animals responded to dbcAMP (P < 0.05) but not to hCC added in vitro. The in vitro response of luteal cells to added hCG was inhibited by 0,50 and 100% if the animals were injected with low (15-90 IU) or medium (100 IU) between day 6–9 of luteal phase and high (600 IU on day 8 and 9 of luteal phase) doses of dghCG respectively; such treatment had no effect on responsivity of the cells to dbcAMP. The luteal cell responsiveness to dbcAMP in vitro was also blocked if hCG was administered for 10 days beginning day 6 of the luteal phase. Though short term hCG treatment during late luteal phase (from days 12—15) had no effect on luteal function, 10 day treatment beginning day 12 of luteal phase resulted in regain ofin vitro responsiveness to both hCG (P < 0.05) and dbcAMP (P < 0.05) suggesting that luteal rescue can occur even at this late stage. In conclusion, desensitization of the CL to hCG appears to be governed by the dose/period for which it is exposed to hCG/dghCG. That desensitization is due to receptor occupancy is brought out by the fact that (i) this can be achieved by giving a larger dose of hCG over a 2 day period instead of a lower dose of the hormone for a longer (4 to 10 days) period and (ii) the effect can largely be reproduced by using dghCG instead of hCG to block the receptor sites. It appears that to achieve desensitization to dbcAMP also it is necessary to expose the luteal cell to relatively high dose of hCG for more than 4 days  相似文献   
139.
CENP—B的基因表达与细胞周期关系的研究   总被引:1,自引:0,他引:1  
本文以HeLa细胞为材料研究一种着丝粒蛋白CENP-B的基因表达与细胞周期及细胞核骨架的关系。将HeLa细胞同步在不同周期时相,以流式细胞光度术、同位素掺入和ACA着丝粒染色等方法检测细胞同步化效果。我们分别提取了各周期时相细胞的总RNA和Poly(A)~ RNA,用Dot blot和Northern blot杂交方法研究CENP-B在细胞周期中的表达。结果表明,CENP-B基因在细胞周期中的各个时相均有表达,但表达的强度差别很大:G2期表达最强,S期最弱,G1期中的表达介于二者之间;有意义的是CENP-B基因在M期仍然有较强的表达,表现出其在细胞周期中表达的持续性;这种表达的持续性反映了一种可能性:着丝粒、动粒蛋白不断合成,但直到S期后进入G2期时着丝粒、动粒蛋白到一定临界浓度时才开始组装新的动粒。另外,着丝粒、动粒蛋白的持续合成对着丝粒、动粒功能的发挥可能是必需的。用Bam H I限制性内切酶消化处于不同细胞周期时相的HeLa细胞核骨架,提取与核骨架紧密结合的DNA,用~(32)P标记的cDNA为探针研究CENP-B基因与细胞核骨架的结合与其表达的关系。结果证明,在G2期细胞中CENP-B基因表达最强,与细胞核骨架结合最为紧密,G1期细胞中次之,S期中CENP-B基因与核骨架结合最弱,说明CENP-B基因与细胞核骨架结合的紧密度影响其表达强度。  相似文献   
140.
At hatching, Heterobranchus longifilis does not display any primordia of the cephalic skeleton. The latter appears 12 h post–hatching and develops in three stages up to day 16. The first stage (12 h to 2 days) involves almost exclusively the development of the chondrocranium. During the second period (days 3–8), dermal elements of the splanchnocranium appear. The final stage is marked by resorption of the cartilages, progressively replaced by ossifications (days 10–16). At their appearance the elements of the splanchnocranium are fused together, as are the first neurocranial elements. Later, the splanchnocranium splits up. By the time the yolk sac is completely resorbed, the buccal and pharyngeal jaws are present, the suspensoria and hyoid bars are partially developed, and the parasphenoid partially closes the hypophyseal fenestra. These structures delimit a buccal cavity that is probably functional, i.e. capable of participating in the intake of exogenous food. Next to continue its development is principally the splanchnocranium, completing the walls of the buccal cavity. Cartilage resorption parallels the appearance of endochondral ossifications (except for the trabecular bars). Braincase closure begins to accelerate once the buccal system is complete.  相似文献   
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