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1.
肺癌在中国恶性肿瘤的发病率位居第一,随着低剂量薄层CT在肺癌筛查中的广泛应用,临床发现更多表现为非完全实性结节的肺腺癌,目前众多研究使CT影像学特征和肺腺癌病理的关系得到更进一步的认知,虽然CT能对部分非完全实性结节做出定性和定位诊断,但仍有部分非完全实性结节诊断困难,PET-CT结合了病灶的代谢信息和精确的定位信息,从而提高对肺部结节诊断的敏感性、特异性、准确性,综合多个文献PET-CT在非完全实性结节中的诊断分期价值较CT无明显提升,却在评估预后和制定合适手术方案上可以起到一定的作用,本文就PET-CT在SSN中的应用价值进行阐述。 相似文献
2.
We have utilized a key biochemical determinant of muscle fiber type, myosin isoform expression, to investigate the initial developmental program of future fast and slow skeletal muscle fibers. We examined myosin heavy chain (HC) phenotype from the onset of myogenesis in the limb bud muscle masses of the chick embryo through the differentiation of individual fast and slow muscle masses, as well as in newly formed myotubes generated in adult muscle by weight overload. Myosin HC isoform expression was analyzed by immunofluorescence localization with a battery of anti-myosin antibodies and by electrophoretic separation with SDS-PAGE. Results showed that the initial myosin phenotype in all skeletal muscle cells formed during the embryonic period (until at least 8 days in ovo) consisted of expression of a myosin HC which shares antigenic and electrophoretic migratory properties with ventricular myosin and a distinct myosin HC which shares antigenic and electrophoretic migratory properties with fast skeletal isomyosin. Similar results were observed in newly formed myotubes in adult muscle. Future fast and slow muscle fibers could only be discriminated from each other in developing limb bud muscles by the onset of expression of slow skeletal myosin HC at 6 days in ovo. Slow skeletal myosin HC was expressed only in myotubes which became slow fibers. These findings suggest that the initial commitment of skeletal muscle progenitor cells is to a common skeletal muscle lineage and that commitment to a fiber-specific lineage may not occur until after localization of myogenic cells in appropriate premuscle masses. Thus, the process of localization, or events which occur soon thereafter, may be involved in determining fiber type. 相似文献
3.
Characterization of the Pseudomonas aeruginosa recA gene: the Les- phenotype. 总被引:3,自引:2,他引:1
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The Les- phenotype (lysogeny establishment deficient) is a pleiotropic effect of the lesB908 mutation of Pseudomonas aeruginosa PAO. lesB908-containing strains are also (i) deficient in general recombination, (ii) sensitive to UV irradiation, and (iii) deficient in UV-stimulated induction of prophages. The P. aeruginosa recA-containing plasmid pKML3001 complemented each of these pleiotropic characteristics of the lesB908 mutation, supporting the hypothesis that lesB908 is an allele of the P. aeruginosa recA gene. The phenotypic effects of the lesB908 mutation may be best explained by the hypothesis that the lesB908 gene product is altered in such a way that it has lost synaptase activity but possesses intrinsic protease activity in the absence of DNA damage. The Les- phenotype is a result of the rapid destruction of newly synthesized phage repressor, resulting in lytic growth of the infecting virus. This hypothesis is consistent with the observations that increasing the number of copies of the phage repressor gene by increasing the multiplicity of infection (i.e., average number of phage genomes per cell) or by introducing the cloned phage repressor gene into a lesB908 mutant will also suppress the Les- phenotype in a phage-specific fashion. 相似文献
4.
烟青虫感染核型多角体病毒后围食膜的病变 总被引:3,自引:1,他引:3
昆虫的围食膜是衬在昆虫中肠内一种网状的结构,它可充作虫体抵御外来病原侵染的一道屏障。关于鳞翅目昆虫幼虫感染了昆虫病毒后围食膜的病变问题,国内外鲜有报道。尤锡镇和康慧娟(1985)曾以实验证明家蚕围食膜对核型多角体病毒有灭活作用,而且认为核型多角体病毒不能侵染和破坏围食膜。Derksen和Granados(1988)则证明染病幼虫的围食膜因不同杆状病毒(包括两种核型多角体病 相似文献
5.
对κ-卡拉胶进行酸降解得到三种卡拉胶低聚糖,并进一步琥珀酰基化得到分子量分别为2720、4000和5960的κ-卡拉胶琥珀酰衍生物(A、B和C)。对产物进行FT-IR表征,并测得其琥珀酰基取代度(DS)分别为0.61、0.29和0.83。检测了三种κ-卡拉胶琥珀酰衍生物对超氧阴离子自由基O2.-、DPPH自由基、羟基自由基.OH以及过氧化氢的清除活性。结果表明:随着取代度的增加,其清除超氧阴离子自由基O2.-和DPPH自由基的能力增强;随着分子量的增加,其清除羟基自由基.OH和过氧化氢的能力增强。这可能与衍生物的羟基含量、取代基团的性质以及取代度等因素有关。 相似文献
6.
7.
RG Maharaj C Alexander C H Bridglal A Edwards H Mohammed TA Rampaul S Sanchez GP Tanwing K Thomas 《Mental health in family medicine》2013,10(2):81-88
Objectives Somatoform disorders are common in international primary care settings, but have been little studied in the developing world. The objective of this study was to determine the prevalence of severe undifferentiated somatoform disorder, and its relationship to depression and anxiety, among patients attending walk-in clinics in Trinidad.Methods The study participants, who were all aged 18 years or older and attending walk-in clinics at 16 randomly selected health centres, were surveyed between May and August 2007 using the PRIME-MD questionnaire.Results There were 594 participants (the response rate was 92%), of whom 72.7% were female. Their ages ranged from 18 to 93 years, and 54.5% were over 50 years of age. In total, 37.2% were married and 25.9% were single. Indo-Trinidadians represented 43.1% and Afro-Trinidadians represented 36% of the study sample; 56.5% of the participants reported that their income was less than US$ 400 per month, and 65.7% were unemployed. At walk-in clinics in Trinidad, the estimated prevalence of severe undifferentiated somatoform disorder was 10.3% (95% CI: 7.86–12.74), that of hypochondriasis was 28.5% (95% CI: 24.9–32.1), and that of body dysmorphic disorder was 15.8% (95% CI: 11.9–18.7). Severe undifferentiated somatoform disorder was statistically significantly associated with gender and ethnicity but not with age, level of education, employment status or income. Chi-square testing found significant associations between the presence of severe undifferentiated somatoform disorder and both depression and anxiety (P < 0.05), between hypochondriasis and both anxiety and depression (P < 0.05), and between body dysmorphic disorder and depression (P < 0.05) but not anxiety. Regression analysis suggested that the demographic features that predicted severe undifferentiated somatoform disorder were being female or Indo-Trinidadian.Conclusions Walk-in clinics in Trinidad that serve older patients on a lower income have a high proportion of patients with somatoform disorders as measured by the PRIME-MD scale. These patients exhibit many features of anxiety and depression. These findings have implications for medical training and service delivery. 相似文献
8.
Kuo YM Crawford F Mullan M Kokjohn TA Emmerling MR Weller RO Roher AE 《Molecular medicine (Cambridge, Mass.)》2000,6(5):430-439
BACKGROUND: Amyloid-beta (A beta) accumulates in plaques and as cerebral amyloid angiopathy (CAA) in the brains of both Alzheimer's disease (AD) patients and transgenic A betaPPswe/tg2576 (tg2576) mice. Increasingly, evidence in humans and mice shows this process to be modulated by apolipoprotein E (apoE). MATERIALS AND METHODS: To explore this relationship, we measured apoE and A beta levels in brains of tg2576 mice and controls at intervals between 2 and 20 months. In addition, A beta concentrations in plasma and muscle of these animals were also quantified. RESULTS: Quite strikingly, we found that the amount of tg2576 mice brain apoE was elevated by an average of 45%, relative to the control mice from 2 months on. The level of brain apoE soared after 14 months to almost 60% greater than the level found in control mice. A beta concentrations in brains before 9 months were less than 2 ng/mg of protein, but by 14 months concentrations rose to 8.7 ng/mg, and by 20 months to 47 ng/mg. In plasma, we noted that the levels of A beta in tg2576 mice declined from above 30 ng/ml prior to 12 months to 14 ng/ml by 14 months. Histology showed that A beta plaques and CAA began to be discernible in the tg2576 mice at about 9 and 20 months of age, respectively. CONCLUSIONS: ApoE was immunocytochemically detected in neuritic plaques that were positive for thioflavine-S. We suggest that the elevation of brain apoE in tg2576 mice participates in an age-related dysregulation of A beta clearance and signals the start of A beta sequestration during the time of cognitive dysfunction. 相似文献
9.
Martin EL Reinhardt RL Baum LL Becker MR Shaffer JJ Kokjohn TA 《Canadian journal of microbiology》2000,46(2):180-187
Both the moderately halophilic bacterium, Halomonas elongata, and the extremely halophilic archaea, Halobacterium salinarum, can be found in hypersaline environments (e.g., salterns). On complex media, H. elongata grows over a salt range of 0.05-5.2 M, whereas, H. salinarum multiplies over a salt range of 2.5-5.2 M. The purpose of this study was to illustrate the effect that solar (UV-A and UV-B) and germicidal radiation (UV-C) had on the growth patterns of these bacteria at varied salt concentrations. Halomonas elongata grown on a complex medium at 0.05, 1.37, and 4.3 M NaCl was found to be more sensitive to UV-A and UV-B radiation, as the salt concentration of the medium increased. Halobacterium salinarum grown on a complex medium at 3.0 and 4.3 M NaCl did not show a significant drop in viability after 39.3 kJ.m-2 of UV-A and UV-B exposure. When exposed to UV-C, H. elongata exhibited substantially more sensitivity than H. salinarum. In H. elongata, differential sensitivity to UV-C was observed. At 0.05 M NaCl, H. elongata was less sensitive to UV-C than at 1.37 and 4.3 M NaCl. Both bacteria showed some photoreactivation when incubated under visible light following both UV-A, UV-B, and UV-C exposure. Mutagenesis following UV-C exposure was demonstrated by both organisms. 相似文献
10.
Shin-Ru Shih Tzu-Yun Chu Gadarla Randheer Reddy Sung-Nain Tseng Hsiun-Ling Chen Wen-Fang Tang Ming-sian Wu Jiann-Yih Yeh Yu-Sheng Chao John TA Hsu Hsing-Pang Hsieh Jim-Tong Horng 《Journal of biomedical science》2010,17(1):13