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101.
C. Vilches J.-M. Garcia-Pacheco R. de Pablo S. Puente M. Kreisler 《Tissue antigens》1996,48(5):589-592
A novel HLA-DQB1 allele was detected by oligotyping in the Bubi population of Equatorial Guinea. In order to characterize the new allelic variant, a RT-PCR method which permitted the cloning of its complete coding region was designed. With this method, we have determined the nucleotide sequence of the new DQB1*0612 allele, related to *0604 and *0609 but differing from them at polymorphic codon 70. A proposal for the improvement of the sequencing strategies of HLA class II alleles is made. 相似文献
102.
Hans-Jürgen Rode Joachim Jakob Bugert Michaela Handermann Paul Schnitzler Roland Kehm Waltraud Janssen Hajo Delius Gholamreza Darai 《Virus genes》1994,9(1):61-75
The complete DNA nucleotide sequence of theEcoRI DNA fragment N (0.235 to 0.258 viral map units) of equine herpes virus type 2 (EHV-2) strain T400/3 was determined. This DNA fragment comprises 4237 bp with a base composition of 55.23% G+C and 44.77% A+T. Nineteen open reading frames (ORFs) of 50-287 amino acid (aa) residues were detected. ORF number 10 is located between the nucleotide position 2220 and 2756 coding for a protein of 179 amino acid residues. This protein shows significant homology to the cytokine synthesis inhibitory factor (CSIF; interleukin 10) of human (76.4%) and mouse (68.5%), and to the Epstein-Barr virus (EBV) protein BCRF1 (70.6%). The existence of an interleukin 10 (IL-10) analogous gene within the genome of the EHV-2 was confirmed by screening the genome of nine EHV-2 strains using specific oligonucleotide primers corresponding to the 5 and 3 region of this particular gene by polymerase chain reaction. In all experiments an 870 bp DNA product was amplified. The specifity of the amplified DNA fragments obtained from individual EHV-2 strains was confirmed by DNA-DNA hybridization experiments. The DNA sequence analysis of the amplified DNA products of the EHV-2 strain LK was carried out. This analysis revealed the identity of the corresponding IL-10 gene (540 bp) of this strain to the IL-10 gene of EHV-2 strain T400/3. The presented data indicate that the EHV-2 genome harbors a viral interleukin 10-like gene. This is further evidence that the IL-10 gene can be present in the genomes of members of the Herpesviridae family. 相似文献
103.
Kohji Okabe Kenji Kitamura Hirosi Kuriyama 《Pflügers Archiv : European journal of physiology》1987,409(6):561-568
The 4-aminopyridine (4AP) sensitive outward current of enzymatically dispersed single smooth muscle cells of the rabbit main pulmonary artery were investigated using the voltage clamp method. When the cell was exposed to physiological salt solution (PSS) in the bath and high K+ in the pipette no inward current was generated by depolarization of the membrane, but when 4AP was present in the bath or when Cs+ with tetraethylammonium+ (Cs+-TEA+) in the pipette, an inward current was generated. This current was enhanced by Ba2+ or high Ca2+ and was blocked by inorganic or organic Ca2+ channel blockers.The outward current was partly inhibited by the Ca2+ channel blockers, Ca2+-free or Mn2+ containing solution. The residual outward current was blocked by external application of 10 mM 4AP, whereas it was inhibited by half with 100 mM TEA+. To investigate further natures of 4AP sensitive outward current, the following experiments were done in the bath solution containing 2.5 mM Mn2+. The reversal potential of this outward current, estimated from the tail current, remained the same in Na+-deficient solution, but shifted to near the K+-equilibrium potential in Cl– deficient solution. Thus, the main current carrier for the outward current seems to be K+, but Cl– may participate to some extent. The amplitude of the outward current decreased slowly. However, the reversal potential was not changed, suggesting the reduction in amplitude of the outward current was not due to the accumulation of K+ on the outer surface of the membrane. As 4AP inhibited the outward current to a greater extent at lower than higher membrane potential levels, 4AP bound to the channel may be dislodged at higher levels. When pH of the bath solution was modified from 7.3 to 8.0, inhibitory actions of 4AP were enhanced (pKa value of 4AP=9.17). Thus, a non-ionized form of 4AP may act as a channel blocker. We conclude that in smooth muscle cells of the pulmonary artery, lack of an action potential in physiological solution may partly be due to a small inward current as well as a large contribution of the 4AP sensitive outward current. 相似文献
104.
Activation of N-methyl-D-aspartate (NMDA) receptors can induce tetrodotoxin (TTX)-resistant membrane potential oscillations as well as fictive locomotion in the in vitro preparation of the lamprey spinal cord. The ionic basis of these oscillations were investigated in the presence of N-methyl-D,L-aspartate and TTX. Addition of blocking agents (2-amino-5-phosphonovalerate and tetraethylammonium (TEA)) and selective removal or substitution of certain ions (Mg2+, Ca2+, Na+, Ba2+) were used in the analysis of the oscillations. The depolarizing phase of the oscillation requires Na+ ions but not Ca2+ ions. The depolarization becomes larger if TEA is administered in the bath, which presumably is due to a blockade of potassium (K+) channels activated during the depolarizing phase. The repolarization appears to depend on a Ca2+ entry, which presumably acts indirectly by an activation of Ca2+-dependent K+ channels. Together with the NMDA-induced voltage dependence, this will bring the membrane potential back down to a hyperpolarized level. 相似文献
105.
N. Casamitjana J. Gil E. Campos M. Santos N. Nogués A. Ribera E. Palou 《Tissue antigens》2001,58(4):269-271
We report here the identification of a novel DQB1*06 allele, DQB1*0618, found in a bone marrow donor. The new allele was detected during routine DNA-based HLA typing by an ambiguous pattern of probe hybridization, obtained by polymerase chain reaction using sequence-specific oligonucleotides (PCR-SSO). Molecular cloning and sequencing confirmed that the new allele is identical to DQB1*0609 at exon 2 except for 3 nucleotide substitutions at positions 353, 356 and 367, also found in other alleles. These nucleotide changes may explain its anomalous reactivity. 相似文献
106.
用血清学方法研究显示中国人胰岛素依赖性糖尿病(IDDM)与HLA-DR9相关。鉴于白种人中的研究显示IDDM与HLA-DQβ链第57位氨基酸相关,Asp-57对IDDM呈抗性,non-Asp与IDDM易感性相关。我们用PCR技术扩增了中国人中血清学DR9纯合的IDDM患者和正常对照的HLA-DQB1基因第二外显子并测定了核苷酸顺序,结果未发现IDDM特异HLA-DQB1等位基因,但发现IDDM病人HLA-DQB157位均为天冬氨酸。表明中国IDDM患者中的HLA-DQB157位天冬氨酸不一定具有保护个体抵抗IDDM的足够能力。IDDM易感性可能涉及多个基因位点的变化,另外还可能与其它遗传因素及环境因素有关。 相似文献
107.
H. Dlouhá B. Bíbr J. Ježek J. Zicha 《Pflügers Archiv : European journal of physiology》1976,366(2-3):277-279
Summary In 20, 40 and 60-day-old rats the filtration rate was studied, using Baines modification of Hanssen's Na4Fe(14CN)6 method enabeling the determination of single nephron glomerular filtration rate (SNGFR) ratio between superficial (S), intercortical (I) and juxtamedullary (J) nephrons. The proximal tubule lengths were determined as well. A close correlation was obtained between age and S/I, I/J and S/J of proximal tubule lengths and between age and I/J, S/J14C-activities of ferrocyanide. Presented findings confirm the data on the increasing role of superficial nephrons in the course of postnatal development of rat. 相似文献
108.
A common Ile796Val polymorphism of the human SREBP cleavage-activating protein (SCAP) gene 总被引:3,自引:0,他引:3
We identified a new common amino acid polymorphism of isoleucine/valine at codon 796 in exon 16 of the gene for human sterol
regulatory element binding protein (SREBP) cleavage-activating protein (SCAP), a central regulator of lipid synthesis and
metabolism in animal cells. It can be detected as an MslI restriction fragment length polymorphism. The allelic frequencies were: isoleucine (A) allele, 0.57 and valine (G) allele,
0.43. This polymorphism may be useful for genetic studies of disorders affecting intracellular lipid metabolism and hyperlipidemia.
Received: August 17, 1999 / Accepted: August 19, 1999 相似文献
109.
Grande G Cafarelli E 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2003,150(4):449-457
Vibration of the patellar tendon recruits motor units in the knee extensors via excitation of muscle spindles and subsequent
Ia afferent input to the α-motoneuron pool. Our first purpose was to determine if the recruitment threshold and firing rate
of the same motor unit differed when recruited involuntarily via reflex or voluntarily via descending spinal pathways. Although
Ia input is excitatory to the α-motoneuron pool, it has also been shown paradoxically to inhibit itself. Our second purpose
was to determine if vibration of the patellar tendon during a voluntary knee extension causes a change in the firing rate
of already recruited motor units. In the first protocol, 10 subjects voluntarily reproduced the same isometric force profile
of the knee extensors that was elicited by vibration of the patellar tendon. Single motor unit recordings from the vastus
lateralis (VL) were obtained with tungsten microelectrodes and unitary behaviour was examined during both reflex and voluntary
knee extensions. Recordings from 135 single motor units showed that both recruitment thresholds and firing rates were lower
during reflex contractions. In the second protocol, 7 subjects maintained a voluntary knee extension at 30 N for approximately
40–45 s. Three bursts of patellar tendon vibration were superimposed at regular intervals throughout the contraction and changes
in the firing rate of already recruited motor units were examined. A total of 35 motor units were recorded and each burst
of superimposed vibration caused a momentary reduction in the firing rates and recruitment of additional units. Our data provide
evidence that Ia input modulates the recruitment thresholds and firing rates of motor units providing more flexibility within
the neuromuscular system to grade force at low levels of force production.
Electronic Publication 相似文献
110.
M. Watanabe 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1990,80(2):296-309
Summary Single unit activity was recorded from the dorsolateral prefrontal cortex of two monkeys which were trained on a stimulus-reward association task. The monkeys were trained on a reaction time task overlapped with a classical conditioning paradigm. The sequential events of the task were as follows: (1) lever pressing to start the trial; (2) presentation of a visual cue for 1 s; (3) delay period of 1 s; (4) imperative stimulus presentation; and (5) release of the lever by the animal. The visual cue signaled whether or not a drop of fruit juice would be given (its associative significance) for the animal's release response instead of signaling what response the animal should perform (its behavioral significance). In this task, the animal had to release the lever even on the trial where no juice was given in order to advance to the next trial. A total of 423 units showed activity changes in relation to one or more of the task events, such as the cue presentation, delay, release response and reward delivery. Among 313 units which showed cue-related activity changes, 179 units showed differential activity in relation to the different cues. A majority of them (Type M; n = 120) showed activity changes in relation to whether the cue indicated juice delivery or not, independent of its physical properties. The activity of 13 units (Type P) was related to the physical properties of the stimulus, and the activity of the remaining 46 units (Type MP) appeared to be related to both aspects of the stimulus. Sustained activity changes during the delay period were observed in 68 Type M, in 3 Type P and in 24 Type MP units. The results suggest that the prefrontal cortex plays important roles in the stimulus-reward association and that prefrontal units are involved in higher order information processing, extracting and retaining the associative significance of the stimulus independent of its physical properties. 相似文献