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101.
Triploid origin of the gibel carp as revealed by 5S rDNA localization and chromosome painting 总被引:2,自引:0,他引:2
5S ribosomal DNA (rDNA) was isolated and sequenced from the gibel carp Carassius auratus gibelio with 162 chromosomes and crucian carp Carassius auratus with 100 chromosomes, and fluorescent probes for chromosome localization were prepared to ascertain the ploidy origin and
evolutionary relationship between the two species. Using fluorescence in-situ hybridization (FISH), major 5S rDNA signals were localized to the short arms of three subtelocentric chromosomes in the gibel
carp and to the short arms of two subtelocentrics in the crucian carp. In addition, some minor signals were detected on other
chromosomes of both species. Simultaneously, six chromosomes were microdissected from the gibel carp metaphase spreads using
glass needles, and the isolated chromosomes were amplified in vitro by degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR). Significantly, when the DOP-PCR-generated probes
prepared from each single chromosome were hybridized, three same-sized chromosomes were painted in each gibel carp metaphase,
whereas only two painted chromosomes were observed in each crucian carp metaphase spread. The data indicate that gibel carp
is of triploid origin in comparison with diploid crucian carp. 相似文献
102.
Dr C. J. Whitters T. W. Macfarlane D. Mackenzie H. Moseley R. Strang 《Lasers in medical science》1994,9(4):297-303
Pulsed Nd-YAG laser irradiation of bacteria has been suggested as a possible means of treating contaminated intra-oral sites
although relatively few studies have been conducted. In this investigation, the antimicrobial activity of a pulsed Nd-YAG
laser was assessed in vitro for a range of oral bacteria using several pulse energies and exposure durations. Pure cultures
of each organism were lased in saline suspensions followed by standard colony counting techniques for test and control samples.
Microbial inhibition was found to be organism-dependent and varied with energy dose and pulse energy. For all nine test species
120-mJ laser pulses proved more efficient than 80-mJ pulses, with 99.9% kills compared with around 90% kills after exposure
to 1800 pulses. These killing activity levels compare favourably with those achieved with other lasers in vitro. 相似文献
103.
M Buchelt H P Kutschera T Katterschafka H Kiss B Schneider R Ullrich 《Lasers in surgery and medicine》1992,12(4):375-381
Erb:YAG and Hol:YAG laser ablation rates of fibrocartilage and nucleus pulposus were measured in vitro simulating clinical conditions. After ablation macroscopic and microscopic appearance of the ablation site was investigated. Hol:YAG and Erb:YAG laser mean ablation rates increased almost linearly with rising energies, showing higher total ablation rates for the Hol:YAG laser due to its higher achievable energy density. At comparable energy densities the Erb:YAG laser appears to be more effective with respect to the corresponding ablation rates. Consequently, the ablational threshold proved to be lower for the Erb:YAG laser. Whereas during Hol:YAG laser ablation, some smoke formation and considerable tissue shrinking occurred, these effects could not be observed during Erb:YAG laser ablation. Consequently macroscopic and microscopic inspection showed some thermal damage after Hol:YAG and only minimal alterations after Erb:YAG laser ablation. Adjacent thermal damage was determined and proved to be lower for the Erb:YAG laser. In our opinion the characteristics of each laser system provide certain advantages for special clinical indications. 相似文献
104.
Summary To characterize and compare the pathologic, hemodynamic and electrocardiographic changes of both transeatheter laser and electrical
energy on ventricle, 33 subendocardial myocardium lesions were induced at energy 60, 120 and 240 Joules by either transcatheter
laser irradiation or electrical shock in 7 anesthetized dogs. The following results were observed: 1) Both laser and electrical
ablation on myocardium created nonhomogeneous myocardium injury, but laser ablation caused mainly focal tissue vaporization
and necrosis, while electrical shock induced widespread tissue degenerations; 2) Both laser and electrical induced-lesion
dimensions increased parallel to the total dosage of energy; 3) Laser ablation caused mainly (90%) single ventricular premature
beats and 86 % of them occurred within the first minute after energy discharged, while ventricular tachycardias were found
in any electrical energy groups; ventricular fibrillations occurring during laser and electrical ablation were 5 % and 13
% respectively (P< 0.01): 4) A decrease in aortic blood pressure and an increase in central verous pressure induced by laser ablation were
significantly less than that produced by the same amount of electrical energy (P<0.0l). Our preliminary results have shown that transeatheter laser ablation has great potential for becoming a practical
method in the management of refractory tachycardias. 相似文献
105.
目的:定量分析乳牙合面的龋病敏感点位,为指导临床预防和治疗龋病提供依据。方法:采用激光荧光检测仪(DIAGNOdent)检测156名5~6岁儿童共561颗患龋的乳磨牙合面,记录合面龋坏最严重的位点。结果:在上颌第2乳磨牙中,龋坏最严重的位点有60.1%发生在远中窝。在下颌第2乳磨牙中,龋坏最严重的位点有51.2%发生在舌沟;而在下颌第1乳磨牙中,龋坏最严重的位点则易发生在远中窝,占该牙记录位点的34.9%。结论:不同的牙合面患龋严重部位具有统计学规律,提示这些位点是龋坏容易发生和发展的地方,是临床上预防和治疗不可忽略的重要部位。 相似文献
106.
弱激光血疗法的发展及展望 总被引:3,自引:1,他引:2
本文主要介绍了弱激光血疗的机制及其在我国的发展过程.弱激光血疗法起源于前苏联的紫外光量子疗法,传入我国后经历了静脉内照射疗法,离体血液激光照射回输疗法,口咽部照射伴吸氧疗法,鼻腔内照射疗法等.本文对各种疗法的特点及临床应用进行了详细叙述.有些学者认为,中医的观点也能揭示激光血疗的机制.从中医辨证的角度,人的体质分为虚证和实证.结合中医针灸的虚则补之,实则泻之的原理,根据患者的虚实状况,采用含有中医补泻信息的调制激光照射血液,同时加照相关敏感穴位,促进疗效,以体现中医的辨证施治的原则可取得更好的疗效. 相似文献
107.
In this study we test the theory that the presence of the conserved vertebrate telomeric sequence (T(2)AG(3))(n) at the centromeres of Australian marsupial 2n = 14 complements is evidence that these karyotypes are recently derived, which is contrary to the generally held view that the 2n = 14 karyotype is ancestral for Australasian and American marsupials. Here we compare the distribution of the (T(2)AG(3))( n ) sequence and constitutive heterochromatin in the presumed ancestral 2n = 14 complement and in complements with known rearrangements. We found that where there were moderate to large amounts of constitutive heterochromatin, the distribution of the (T(2)AG(3))(n) sequence reflected its presence as a native component of satellite DNA rather than its involvement in past rearrangements. The presence of centromeric heterochromatin in all Australian 2n = 14 complements therefore suggests that centromeric sites of the (T(2)AG(3))(n) sequence do not represent evidence for recent rearrangements. 相似文献
108.
Laying the Cytotaxonomic Foundations of a New Model Grass, Brachypodium distachyon (L.) Beauv. 总被引:2,自引:0,他引:2
Brachypodium distachyon is a ubiquitous, temperate grass species which is being developed and exploited as an alternative model to rice, in order to gain access to important syntenic regions of the genomes of less tractable relatives such as wheat. As part of this initiative, this paper describes for the first time the cytotaxonomy of members of the polyploid series of this species, and challenges the assumption that the series evolved simply by chromosome doubling. In situ hybridization using genomic DNA probes and rDNA markers uncovers a hybrid origin of several of the polyploid ecotypes, and sheds light upon the complex evolution of this species and its close relatives. 相似文献
109.
595nm激光对兔耳瘢痕成纤维细胞增殖与凋亡的影响 总被引:2,自引:2,他引:0
目的:探讨595nmVbeam激光照射对增生性瘢痕动物模型伤口愈合过程中成纤维细胞增殖与凋亡的影响。方法:成年大耳白兔20只,建立兔耳腹侧面增生性瘢痕模型,对比研究在瘢痕形成过程中595nmVbeam激光照射对兔耳瘢痕成纤维细胞的影响,采用免疫组化方法检测增殖细胞核抗原(PCNA)蛋白表达和细胞凋亡的原位检测。结果:兔耳增生性瘢痕经595nmVbeam激光照射后,按不同时间段取材进行免疫组化染色并与对照组比较,高倍镜下观察结果,显示PCNA蛋白表达明显减弱,细胞凋亡增加。结论:595nmVbeam激光照射可抑制兔耳增生性瘢痕成纤维细胞的增殖过程,诱导细胞凋亡。应用595nmVbeam激光预防和治疗瘢痕是可行的。 相似文献
110.
Tobias Forschner Stefan Buchholtz Eggert Stockfleth 《Journal der Deutschen Dermatologischen Gesellschaft》2007,5(6):467-475
Vitiligo is a skin disease with a worldwide prevalence ranging from 0.5% to 4%. Conservative therapies include photochemotherapy, phototherapy with UVB radiation (broadband UVB 290–320 nm, narrow band UVB 311 nm), systemic steroids and pseudocatalase. Modern therapeutic options include treatment with topical immunomodulators (tacrolimus, pimecrolimus), analogues of vitamin D3, excimer laser and surgery/transplantation. Our analysis compares these therapies for vitiligo and the evidence levels supporting their effectiveness. Conclusions: The face and neck respond best to all therapeutic approaches, while the acral areas are least responsive. For generalized vitiligo, phototherapy with UVB radiation is most effective with the fewest side effects; PUVA is the second best choice.Topical corticosteroids are the preferred drugs for localized vitiligo. They may be replaced by topical immunomodulators which display comparable effectiveness and fewer side effects.The effectiveness of vitamin D analogues is controversial with limited data. Surgical therapy can be very successful, but requires an experienced surgeon and is very demanding of time and facilities, thus limiting its widespread use. L-phenylalanine therapy appears effective on the face but enjoys neither widespread use nor extensive data support. No single therapy for vitiligo can be regarded as the most effective as the success of each treatment modality depends on the type and location of vitiligo. 相似文献