抑癌基因ING1蛋白在早期肺癌组织中的表达及意义

目的 研究抑癌基因ING1的蛋白表达产物p33ING1在肺癌发生、发展中的作用.方法 用免疫组化SP法检测p33ING1在40例肺癌和10例正常肺组织中的表达.结果 p33ING1在肺癌组织中的阳性表达率(57.5%)明显低于正常肺组织(100.0%),P<0.05.p33ING1表达与淋巴结转移、TNM分期及组织分化有关.结论 p33ING1低表达在肺癌的发生、发展中可能起重要作用;其对判断肺癌的恶性程度、浸润甚至转移有重要价值.     

大肠癌C-erbB-2蛋白产物的表达

大肠癌Ｃ＿ｅｒｂＢ＿２蛋白产物的表达黄文谢宗贵王要军孙自勤济南军区总医院消化科山东省济南市２５００３１主题词癌基因结直肠肿瘤免疫组织化学Ｓｕｂｊｅｃｔｈｅａｄｉｎｇｓｏｎｃｏｇｅｎｅｓｃｏｌｏｒｅｃｔａｌｎｅｏｐｌａｓｍｓｉｍｍｕｎｏｈｉｓｔｏｃ...     

抑癌基因p16在胆管癌中表达的意义

目的研究p16基因产物在人肝外胆管癌中的表达及其意义.方法应用免疫组织化学技术检测51例肝外胆管癌组织中p16表达,并分析其意义.结果51例肝外胆管腺癌P16蛋白的阳性率为43.1%,其阳性率在肿瘤的病理分级及神经侵润等方面差异有显著性(P<0.05),中位生存期在P16蛋白阳性的肿瘤中比阴性的长(23mo vs 8mo,P<0.05),P16蛋白阳性比P16阴性肿瘤手术切除率高(52.9% vs 23.5%,P<0.05).结论p16基因可能在胆管肿瘤的发生、发展中起重要作用,与胆管癌分化不良、神经侵润、生存时间及能否切除有密切关系.     

抑癌基因P16在肺鳞癌和肺腺癌中的表达及临床意义

目的 探讨p16基因产物在肺鳞癌和肺腺癌中的表达及其意义。方法 本组56例原发性非小细胞肺癌，其中鳞癌37例，腺癌19例。用免疫组织化学PCR法检测患者肺癌新鲜标本p16蛋白表达水平。结果 56例肺癌标本中p16蛋白阳性表达率为58.9%（33／56），伴有淋巴结转移者其阳性表达率41.4%（12／29）显著低于无淋巴结转移者（P16阳性表达率为77.8%（21／27），P＜0.01）。P16蛋白阴性表达者的1年、3年生存率分别为59.7%、44.1%，显著低于p16蛋白阳性表达者85.2%、71.8%。结论 p16蛋白表达与肺鳞癌和肺腺癌的组织类型，淋巴结转移及预后有关。p16蛋白状态可作为判断肺癌预后的指标之一。     

癌基因和抑癌基因在肺癌研究中的应用和发展趋势

癌基因和抑癌基因在肺癌研究中的应用和发展趋势王孟山张广宇肺癌对人类健康的危害日益严重，最新统计表明：肺癌死亡率上升幅度居各类肿瘤之首，至９０年代已达１７．５４／１０万。现代肿瘤分子生物学研究揭示：肺癌的发生、发展和演变与细胞原癌基因的激活和抑癌基因的...     

胃癌p16基因产物表达的研究

胃癌ｐ１６基因产物表达的研究张丹，王继红，姜彦多，刘晓波抑癌基因的缺失和功能丧失在肿瘤发生发展中起着十分重要的作用。ｐ１６基因是最近发现的一个参与细胞周期调控的抑癌基因，其抑癌作用和在恶性肿瘤中的高频率突变［１］，提示参与了肿瘤的发生过程。本研究应用...     

肝细胞癌中wwox基因启动子甲基化与蛋白表达的关系

目的:探讨wwox基因启动子甲基化及蛋白表达与肝细胞性肝癌的关系.方法:通过甲基化特异性PCR(methylation specific polymerase chain reaction,MSP)方法及免疫组织化学(immunohistochemestry,IHC)法分别检测60例肝细胞性肝癌组织和癌旁组织中wwox基因启动子甲基化状态和蛋白表达水平.结果:癌组织及癌旁组织中wwox基因启动子甲基化阳性率分别为41.67%(25/60)和8.33%(5/60)(P=0.000).WWOX蛋白在癌和癌旁组织中的表达具有显著性差异[35.00%(21/60)vs70.00%(42/60),P=0.001].wwox基因启动子甲基化和蛋白表达与肝外转移、肿瘤直径、肿瘤细胞分化密切相关(P=0.007,0.014,0.011);WWOX蛋白表达与临床分期、肿瘤直径、肿瘤细胞分化密切相关(P=0.018、0.023、0.001).wwox基因启动子甲基化与蛋白表达显著负相关(γ=-0.408,P=0.001).结论:启动子区甲基化是wwox基因失活的重要机制.wwox启动子区异常甲基化可能参与了肝癌的发生发展,在肝癌的进展发挥重要作用.     

肿瘤抑制基因CDKN2与肺癌

肿瘤抑制基因ＣＤＫＮ２与肺癌温桂兰范希光饶纬华肿瘤抑制基因ＣＤＫＮ２也称ｐ１６ＩＮＫ４Ａ、ＭＴＳ１，自从１９９４年美国盐湖城Ｋａｍｂ和Ｋｏｌｎｉｃｋ报道以来，受到医学界广泛关注，已成为肿瘤分子生物学、分子遗传学等领域研究的热点。研究表明ＣＤＫＮ２基因...     

CD105在肺癌组织中的表达及其与预后的关系

应用免疫组织化学SP法检测CD105在70份肺癌癌组织及40份癌旁组织标本中的表达,结果CD105在癌组织中的阳性表达率明显高于癌旁组织,其表达与肺癌临床分期有关;CD105不同表达的化疗患者中位生存时间明显长于非化疗者,以化疗CD105阴性者最长;COX回归分析显示,CD105与肺癌患者的预后有关.认为CD105与肺癌的发生、发展密切相关,可作为评价肺癌预后的指标.     

Classification and characterization of hereditary types 2A, 2B, 2C, 2D, 2E, 2M, 2N, and 2U (unclassifiable) von Willebrand disease.

All variants of type 2 von Willebrand disease (VWD) patients, except 2N, show a defective von Willebrand factor (VWF) protein (on cross immunoelectrophoresis or multimeric analysis), decreased ratios for VWF:RCo/Ag and VWF:CB/Ag and prolonged bleeding time. The bleeding time is normal and FVIII:C levels are clearly lower than VWF:Ag in type 2N VWD. High resolution multimeric analysis of VWF in plasma demonstrates that proteolysis of VWF is increased in type 2A and 2B VWD with increased triplet structure of each visuable band (not present in types 2M and 2U), and that proteolysis of VWF is minimal in type 2C, 2D, and 2E variants that show aberrant multimeric structure of individual oligomers. VWD 2B differs from 2A by normal VWF in platelets, and increased ristocetine-induced platelet aggregation (RIPA). RIPA, which very likely reflects the VWF content of platelets, is normal in mild, decreased in moderate, and absent in severe type 2A VWD. RIPA is decreased or absent in 2M, 2U, 2C, and 2D, variable in 2E, and normal in 2N. VWD 2M is usually mild and characterized by decreased VWF:RCo and RIPA, a normal or near normal VWF multimeric pattern in a low resolution agarose gel. VWD 2A-like or unclassifiable (2U) is distinct from 2A and 2B and typically featured by low VWF:RCo and RIPA with the relative lack of high large VWF multimers. VWD type 2C is recessive and shows a characteristic multimeric pattern with a lack of high molecular weight multimers, the presence of one single-banded multimers instead of triplets caused by homozygosity or double hereozygosity for a mutation in the multimerization part of VWF gene. Autosomal dominant type 2D is rare and characterized by the lack of high molecular weight multimers and the presence of a characteristic intervening subband between individual oligimers due to mutation in the dimerization part of the VWF gene. In VWD type 2E, the large VWF multimers are missing and the pattern of the individual multimers shows only one clearly identifiable band, and there is no intervening band and no marked increase in the smallest oligomer. 2E appears to be less well defined, is usually autosomal dominant, and accounts for about one third of patients with 2A in a large cohort of VWD patients.     

Different RBC aggregating properties of the Aalpha2Bbeta2gammaA2 and Aalpha2Bbeta2gammaAgamma' subpopulations of human fibrinogen

Human fibrinogen (TF) has been separated into two fractions: F1 - homodimers with respect to the gamma chain, and F2 - heterodimers composed of gammaA and gamma' polypeptides. Their rouleaux-inducing properties were as follows: (1) both, at the same concentration of 0.8%, were less effective than TF; (2) F1 produced larger rouleaux even under static conditions of a hemocytometer where F2 was silent; (3) F2 induced the process when a suspension was gently sheared between microscopic slides. Since the synthetic peptide gamma'(414-427) inhibited the rouleau formation in a mixture with F2, the C-terminal amino acids of the gamma' polypeptide probably bind the molecule to the cell. The inhibition was feebly visible in the native ratio of F1/F2, implicating a compensatory effect of F1.     

Task2 potassium channels set central respiratory CO2 and O2 sensitivity

Task2 K⁺ channel expression in the central nervous system is surprisingly restricted to a few brainstem nuclei, including the retrotrapezoid (RTN) region. All Task2-positive RTN neurons were lost in mice bearing a Phox2b mutation that causes the human congenital central hypoventilation syndrome. In plethysmography, Task2^−/− mice showed disturbed chemosensory function with hypersensitivity to low CO₂ concentrations, leading to hyperventilation. Task2 probably is needed to stabilize the membrane potential of chemoreceptive cells. In addition, Task2^−/− mice lost the long-term hypoxia-induced respiratory decrease whereas the acute carotid-body-mediated increase was maintained. The lack of anoxia-induced respiratory depression in the isolated brainstem–spinal cord preparation suggested a central origin of the phenotype. Task2 activation by reactive oxygen species generated during hypoxia could silence RTN neurons, thus contributing to respiratory depression. These data identify Task2 as a determinant of central O₂ chemoreception and demonstrate that this phenomenon is due to the activity of a small number of neurons located at the ventral medullary surface.     

Influence of Mixed Na2O/K2O on Chemical Durability and Spectral Properties of P2O5-Al2O3-BaO-K2O-Na2O-Nd2O3 Phosphate Glasses

A series of 56P₂O₅-7.5Al₂O₃-5.9BaO-(28.56-x)K₂O-xNa₂O-1.51Nd₂O₃ phosphate glasses with different Na/(Na+K) ratios, which were specially designed for high-power laser application, were prepared by a high-temperature melting method. Except for the density, refractive index, glass transition temperature, and DC conductivity, the chemical durability and spectral properties, as emphasized by high-power and high-energy laser material, were further measured and analyzed. Regarding the chemical durability, the dissolution rates of these glasses do not show an evident mixed alkali effect with increasing the Na/(Na+K) ratio, although the effect is obvious for the glass transition temperature and DC conductivity. To better understand the nature of the dissolution mechanism, the ionic release concentrations of every element are determined. Both Na and K undergo ion exchange, but the ion exchange rate of K is much larger than that of Na. In terms of the spectral properties, the J–O parameters, emission cross-section, radiation lifetime, fluorescence lifetime, effective bandwidth, fluorescence branching ratio, and quantum efficiency are determined from absorption and emission spectra. The trend of Ω₂ deviating from linearity indicates that the coordination environment symmetry of Nd³⁺ ions and the covalence of Nd-O also present an evident mixed alkali effect. The most important finding is that the emission cross-section and fluorescence lifetime of Nd³⁺ ions at 1053 nm were not affected by the change in the Na/K ratio. According to the above experimental results, the optimized value of the Na/K ratio was determined, based on which the 56P₂O₅-7.5Al₂O₃-5.9BaO-(28.56-x)K₂O-xNa₂O-1.51Nd₂O₃ glass maintains a high emission cross-section with good chemical durability.     

Structure-function of Hb Marseille-Long Island [alpha 2 beta 2 N-methionyl-2(NA2) His----Pro

Suspensions of red cells containing Hb Marseille-Long Island showed decreased oxygen affinity and low interaction with 2,3-diphosphoglycerate. Oxygen equilibrium studies of the purified component confirmed these abnormalities. Oxidation rate measurements of carbonmonoxy-Hb Marseille and carbonmonoxy-Hb A by ferricyanide showed an increased rate for the former, suggesting an increased dissociation constant for carbon monoxide. Nuclear Magnetic Resonance spectra in the high field region revealed small changes in the proximal region of the heme pocket. These results indicated that the mutation causes a perturbation at a distance from the mutation site.     

PON2 and ATP2B2 gene polymorphisms with noise-induced hearing loss

Background

Noise-induced hearing loss (NIHL) is a complex disease induced by a combination of genetic and environmental factors. Paraoxonase2 (PON2) gene involved in the regulation of reactive oxygen species, and affecting the vulnerability of cochlea to NIHL, and ATPase, calcium-transporting, plasma membrane 2 (ATP2B2) gene which encodes plasma membrane calcium-transporting ATPase isoform 2 (PMCA2) are the candidate genes relating to the attack of NIHL. In this study, we investigated whether ATP2B2 and PON2 polymorphisms were associated with NIHL in Chinese of Han nationality population.

Methods

We performed a case-control study between six single nucleotide polymorphisms (SNPs) (rs1719571, rs3209637 and rs4327369 within ATP2B2, rs12026, rs7785846 and rs12704796 within PON2) and NIHL in 454 subjects. All the SNPs were genotypes, using the TaqMan MGB probe assay. Odds ratios (ORs) were calculated with 95% confidence intervals (95% CIs) with logistic regression analysis to test the level of association for SNPs.

Results

In our study, 221 subjects with hearing loss and 233 subjects without hearing loss were recruited. The frequencies of the CG and CG + GG genotype of rs12026 (PON2) conferred risk factors for NIHL with adjusted OR values of 2.62 (95% CI, 1.69–4.06) and 2.48 (95% CI, 1.63–3.78), respectively. This kind of significance was also found at locus rs7785846, where genotypes CT and CT + TT were the risk types, with adjusted ORs of 2.52 (95% CI, 1.62–3.93) and 2.35 (95% CI, 1.54–3.58), respectively. We performed stratified analysis per noise exposure level, when it came to rs7785846 and rs12026 in the >92 dB(A) noise exposure group, the subjects who carried heterozygote were of significantly (P<0.01) higher susceptibility to NIHL than homozygote carriers. By contrast, no significantly higher risk was found for any rs12704796 genotypes or any genotypes in ATP2B2 (P>0.05), which may suggest that these SNPs did not have significant effects on noise susceptibility across noise exposure.

Conclusions

Our research suggested that PON2 might play a role in the etiology of NIHL in Chinese of Han nationality population.     

First-order antiferromagnetic transitions of SrMn2P2 and CaMn2P2 single crystals containing corrugated-honeycomb Mn sublattices

SrMn₂P₂ and CaMn₂P₂ are insulators that adopt the trigonal CaAl₂Si₂-type structure containing corrugated Mn honeycomb layers. Magnetic susceptibility χ and heat capacity versus temperature T data reveal a weak first-order antiferromagnetic (AFM) transition at the Néel temperature TN=53(1) K for SrMn₂P₂ and a strong first-order AFM transition at TN=69.8(3) K for CaMn₂P₂. Both compounds exhibit isotropic and nearly T-independent χ(T≤TN), suggesting magnetic structures in which nearest-neighbor moments are aligned at ≈120° to each other. The ³¹P NMR measurements confirm the strong first-order transition in CaMn₂P₂ but show critical slowing down above TN for SrMn₂P₂, thus also evidencing second-order character. The ³¹P NMR measurements indicate that the AFM structure of CaMn₂P₂ is commensurate with the lattice whereas that of SrMn₂P₂ is incommensurate. These first-order AFM transitions are unique among the class of (Ca, Sr, Ba)Mn₂ (P, As, Sb, Bi)₂ compounds that otherwise exhibit second-order AFM transitions. This result challenges our understanding of the circumstances under which first-order AFM transitions occur.

The Mn-based 122-type pnictides AMn2Pn2 (A= Ca, Sr, Ba; Pn = P, As, Sb, Bi) have received attention owing to their close stoichiometric 122-type relationship to high-Tc iron pnictides. The undoped Mn pnictides are local-moment antiferromagnetic (AFM) insulators like the high-Tc cuprate parent compounds (1–3). The BaMn2Pn2 compounds crystallize in the body-centered tetragonal ThCr2Si2 structure as in AFe2As2 (A = Ca, Sr, Ba, Eu), whereas the (Ca,Sr)Mn2Pn2 compounds crystallize in the trigonal CaAl2Si2-type structure (4). Recently, density-functional theory (DFT) calculations for the 122 pnictide family have suggested that the trigonal 122 transition-metal pnictides that have the CaAl2Si2 structure might compose a new family of magnetically frustrated materials in which to study the potential superconducting mechanism (5, 6). It had previously been suggested on theoretical grounds that CaMn₂Sb₂ is a fully frustrated classical magnetic system arising from proximity to a tricritical point (7–9).The electrical resistivity ρ and heat capacity Cp versus temperature T of single-crystal CaMn₂P₂ were reported in ref. 10. The compound is an insulator at T = 0 and undergoes a first-order transition of some type at 69.5 K. The Raman spectrum of CaMn₂P₂ at T = 10 K showed new peaks compared to the spectrum at 300 K, whereas the authors’ single-crystal X-ray diffraction measurements showed no difference in the crystal structure at 293 and 40 K. They suggested that the results of the two types of measurements could be reconciled if a superstructure formed below 69.5 K (10). The authors’ magnetic susceptibility χ(T) measurements below 400 K revealed no evidence for a magnetic transition.Here we report the detailed properties of trigonal CaMn₂P₂ and SrMn₂P₂ (11) single crystals. We present the results of single-crystal X-ray diffraction (XRD), electrical resistivity ρ in the ab plane (hexagonal unit cell) versus temperature T, isothermal magnetization versus applied magnetic field M(H), magnetic susceptibility χ(T), heat capacity Cp(H,T), and ³¹P NMR measurements. We find from Cp(T), χ(T), and NMR that CaMn₂P₂ exhibits a strong first-order AFM transition at TN=69.8(3) K whereas SrMn₂P₂ shows a weak first-order transition at TN=53(1) K but with critical slowing down on approaching TN from above as revealed from NMR, a characteristic feature of second-order transitions. Thus, remarkably, the AFM transition in SrMn₂P₂ has characteristics of both first- and second-order transitions. The χ(T) data also reveal the presence of strong isotropic AFM spin fluctuations in the paramagnetic (PM) state above TN up to our maximum measurement temperatures of 900 and 350 K for SrMn₂P₂ and CaMn₂P₂, respectively. This behavior likely arises from spin fluctuations associated with the quasi–two-dimensional nature of the Mn spin layers (12) together with possible contributions from magnetic frustration. Our single-crystal XRD data at room temperature and high-resolution synchrotron XRD data at T = 20 K for SrMn₂P₂ and CaMn₂P₂ demonstrate conclusively that there is no structure change of either compound on cooling below their respective TN.Our studies of SrMn₂P₂ and CaMn₂P₂ thus identify the only known members of the class of materials with general formula AMn2Pn2 containing Mn2+ spins S = 5/2 that exhibit first-order AFM transitions, where A = Ca, Sr, or Ba and the pnictogen Pn= P, As, Sb, or Bi. In particular, only second-order AFM transitions are found in CaMn2As2 (13), SrMn2As2 (13–15), CaMn2Sb2 (8, 9, 16–19), SrMn2Sb2 (16, 19), and CaMn2Bi2 (20).