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51.
陈清轩 《基因组蛋白质组与生物信息学报(英文版)》1995,(1)
DetectionandAnalysisofanEstrous-associatedOviductalGlycoproteinDNAFragmentfromPrimatesbyPCR¥CHENQing-xuan(陈清轩);ClaytonE.Walto... 相似文献
52.
53.
Ansgar Büschges 《Developmental neurobiology》1995,27(4):488-512
Local nonspiking interneurons in the thoracic ganglia of insects are important premotor elements in posture control and locomotion. It was investigated whether these interneurons are involved in the central neuronal circuits generating the oscillatory motor output of the leg muscle system during rhythmic motor activity. Intracellular recordings from premotor nonspiking interneurons were made in the isolated and completely deafferented mesothoracic ganglion of the stick insect in preparations exhibiting rhythmic motor activity induced by the muscarinic agonist pilocarpine. All interneurons investigated provided synaptic drive to one or more motoneuron pools supplying the three proximal leg joints, that is, the thoraco-coxal joint, the coxa-trochanteral joint and the femur-tibia joint. During rhythmicity in 83% (n=67) of the recorded interneurons, three different kinds of synaptic oscillations in membrane potential were observed: (1) Oscillations were closely correlated with the activity of motoneuron pools affected; (2) membrane potential oscillations reflected only certain aspects of motoneuronal rhythmicity; and (3) membrane potential oscillations were correlated mainly with the occurrence of spontaneous recurrent patterns (SRP) of activity in the motoneuron pools. In individual interneurons membrane potential oscillations were associated with phase-dependent changes in the neuron's membrane conductance. Artificial changes in the interneurons' membrane potential strongly influenced motor activity. Injecting current pulses into individual interneurons caused a reset of rhythmicity in motoneurons. Furthermore, current injection into interneurons influenced shape and probability of occurrence for SRPs. Among others, identified nonspiking interneurons that are involved in posture control of leg joints were found to exhibit the above properties. From these results, the following conclusions on the role of nonspiking interneurons in the generation of rhythmic motor activity, and thus potentially also during locomotion, emerge: (1) During rhythmic motor activity most nonspiking interneurons receive strong synaptic drive from central rhythm-generating networks; and (2) individual nonspiking interneurons some of which underlie sensory-motor pathways in posture control, are elements of central neuronal networks that generate alternating activity in antagonistic leg motoneuron pools. © 1995 John Wiley & Sons, Inc. 相似文献
54.
55.
采用聚合酶链反应(Polymeranse Chian Reation,即PCR)技术检测结核分枝杆菌Mycobacterium tuberculosis,一年多来共检测了100例结核(肺、肾结核)患者的痰和尿液标本,结果PCR检出阳性率为81%,对照用储菌涂片抗酸染色法,阳性率为58%,用常规培养法阳性率为20%。而对50例非结核患者的痰和尿液标本的检测,PCR法仍有6%的阳性率,而用涂片或常规培 相似文献
56.
Tatsuo Kawarasaki Tetsuya Kohsaka Masaru Sone Mitsutoshi Yoshida Kimio Bamba 《Molecular reproduction and development》1995,40(4):455-459
This study was carried out to determine whether Y-bearing porcine spermatozoa could be detected by in situ hybridization using a digoxigenin (Dig)-labelled DNA probe specific to the Y chromosome produced by polymerase chain reaction (PCR). A conventional PCR (with Dig-dUTP) was performed using a set of oligonucleotide primers (5′-AAGTGGTCAGCGTGTCCATA-3′ and 5′-TTTCTCCTGTATCCTCCTGC-3′) for 236 bp fragment of porcine male-specific DNA sequence and 1.25 × 104 template white blood cells obtained from a boar. When fluorescence in situ hybridization with the Dig-labelled DNA probe was applied to the metaphase chromosome spreads prepared from both boar and gilts, the fluorescein signal was only detected on the long arm of the Y chromosome. In addition, immunocytochemical detection with the Dig-labelled DNA probe and alkaline phosphatase-labeled anti-Dig was applied to both sperm nuclei pretreated with dithiothreitol and white blood cells; 51% of sperm nuclei and 96% of white blood cells obtained from boar were labelled, whereas none of white blood cells obtained from gilts were labelled with the Dig-labelled DNA probe. The results indicated that in situ hybridization with porcine male-specific DNA probe produced by PCR made possible the direct visualization of Y-bearing porcine spermatozoa by in situ hybridization. © 1995 Wiley-Liss, Inc. 相似文献
57.
Sex-related growth rate differences in preimplantation mouse embryos were investigated. In experiment I, Day 3 embryos were recovered from reproductive tracts, classified according to developmental stage, and cultured for 24 hr in CZB medium containing glucose. Each embryo was then reclassified and stained for measurement of number of nuclei and finally sexed using the polymerase chain reaction. In experiment II, Day 4 embryos were recovered, classified, stained, and sexed as in experiment I immediately after recovery. Morphologically, there were no differences between the sexes in either of the experiments on Day 4. However, based on number of nuclei, the data showed that in vitro conditions support the development of male embryos to the blastocyst stage compared to female embryos. Furthermore, growth rate differences were observed in vivo on Day 3, as females compacted earlier than males. These results suggest that the increased cell proliferation in cultured male embryos is an artifact caused by the in vitro environment. The variation may be due to sex differences in embryonal energy metabolism during the preimplantation stage. The growth difference implies different in vitro requirements of male and female embryos. © 1995 Wiley-Liss, Inc. 相似文献
58.
Evaluation of mass spectrometric techniques for charaterization of engineered proteins 总被引:7,自引:0,他引:7
Roepstorff Peter Schram Karl H. Andersen Jens S. Rafn Kate Baldursson Trausti Krøll Jenny Poulsen Kjeld Knudsen Jens Kristiansen Karsten 《Molecular biotechnology》1995,3(1):1-7
A simple and versatile method of in vitro site-specific mutagenesis based on polymerase chain reaction (PCR) is described.
The complete method required the use of three oligonucleotide primers and two PCRs. The product of the first PCR was used
as one of the primers (megaprimer) in the second PCR. Essentially 100% of the final product incorporated the desired mutation.
The various aspects of the procedure and its application is described in detail. 相似文献
59.
Ralph Rapley 《Molecular biotechnology》1995,3(2):139-154
The exquisite specificity of monoclonal antibodies (MAb) has long provided the potential for creating new reagents for the
in vivo delivery of therapeutic drugs or toxins to defined cellular target sites or improved methods of diagnosis. However,
many difficulties associated with their production, affinity, specificity, and use in vivo have largely confined their application
to research or in vitro diagnostics. This situation is beginning to change with the recent developments in the applied molecular
techniques that allow the engineering of the genes that encode antibodies rather than the manipulation of the intact antibodies
themselves. Techniques, such as the polymerase chain reaction, have provided essential methods with which to generate and
modify the genetic constituents of antibodies, allow their conjugation to toxins or drugs, provide ways of humanizing murine
antibodies, and allow discrete modular antigen binding components to be produced. More recent developments of in vitro expression
systems and powerful phage surface display technologies will without doubt play a major role in future antibody engineering
and in the successful development of new diagnostic and therapeutic antibody-based reagents. 相似文献
60.
Abstract The firefly luciferase gene, luc , was demonstrated to hold promise as a specific marker for monitoring of genetically modified bacteria in the environment. PCR amplification and bioluminescence procedures were modified and compared for environmental monitoring of luc -tagged bacteria, using Escherichia coli as a model. The methods were used to track luc -tagged bacterial cells added to intact sediment core microcosms. Detection limits for the luc -tagged cells were the following, expressed as cells per 0.5 g of sediment: 102 , by PCR amplification; 103 , by whole cell luminescence; and 103 −104 , by measurement of luminescence in cell extracts. 相似文献