GNAS gene mutations affecting XLαs and bone health: A long neglected relationship

The GNAS locus is an imprinted site. The α-subunit of the stimulatory G protein (Gsα) and extralarge variant (XLαs) are the two important products of the GNAS locus. The abnormal expression of Gsα is associated with pseudohypoparathyroidism (PHP) and related disorders, including Albright hereditary osteodystrophy (AHO), pseudopseudohypoparathyroidism (PPHP), and progressive osseous heteroplasia (POH). XLαs protein can mimic the catalytic intracellular synthesis of cyclic adenosine monophosphate (cAMP) by Gsα in response to parathyroid hormone (PTH) stimulation, which may be involved in the pathogenesis of PPHP and POH in patients with paternal GNAS defects. A paternally inherited nonsense variant in the first exon of XLαs in an adult patient may be associated with fractures and osteopetrosis. The relationship between the XLαs product of the GNAS locus and bone remodeling may have been overlooked. Here, we summarize the phenotypes of genetic mouse models and clinical cases of XLαs variations and suggest that the abnormal paternal expression of XLαs may be associated with the development of POH and affect osteoblast and osteoclast differentiation.     

Clonal growth of human acute leukemia cells in serum-free methylcellulose medium

Ｔｈｅｇｒｏｗｔｈｏｆｌｅｕｋｅｍｉａｉｎｓｅｍｉｓｏｌｉｄｃｕｌｔｕｒｅｉｎｖｉｔｒｏｗａｓｄｅｐｅｎｄｅｎｔｏｎｔｈｅｐｒｅｓ－ｅｎｃｅｏｆｅｘｏｇｅｎｏｕｓｓｅｒｕｍ．Ｓｅｒｕｍｉｓａｍｉｘ－ｔｕｒｅｃｏｎｔａｉｎｉｎｇｌａｒｇｅｎｕｍｂｅｒｏｆｕｎｉｄｅｎｔｉｆｉｅｄｃｈｅｍｉｃａｌｃｏｍｐｏｎｅｎｔｓａｎｄｕｎｉｄｅｎｔｉｆｉｅｄｂｉｏ－ｌｏｇｉｃａｌｌｙａｃｔｉｖｅｓｕｂｓｔａｎｃｅｓ［１］,ｗｈｉｃｈｐｒｏｖｉｄｅｔｈｅｎｕｔｒｉｅｎｔｓｎｅｃｅｓｓａｒｙｆｏｒｔｈｅｃｅｌｌｇｒｏ…     

两种LASIK微型角膜刀的临床应用探讨

目的　比较ＫＮ－ ５０００ 型微型角膜刀与Ｍｏｒｉａ 微型角膜刀在ＬＡＳＩＫ 术中制作角膜瓣时的优缺点。方法　选用连续病例５６ 例１０３ 眼,随机分ＫＮ 组和Ｍｏｒｉａ 组,ＫＮ 组２８ 例５３眼,术前近视度数平均为－ ９－２１±７－４１Ｄ,散光≤－５－００Ｄ,Ｍｏｒｉａ 组２８ 人５０ 眼,术前近视度数平均为－１０－４７±３－７３Ｄ,散光≤－２－５０Ｄ,术中分别用ＫＮ－５０００ 微型角膜刀和Ｍｏｒｉａ 微型角膜刀制作角膜瓣。结果　两组病例角膜瓣边缘整齐。基质面：ＫＮ组全部术眼光滑、规则,Ｍｏｒｉａ 组部分术眼有“搓衣板”现象。瓣异常：ＫＮ组游离瓣２ 眼,Ｍｏｒｉａ 组不全瓣５ 眼。ＫＮ组角膜瓣质量优于Ｍｏｒｉａ 组,瓣异常率低于Ｍｏｒｉａ 组。结论　ＫＮ－ ５０００ 微型角膜刀在ＬＡＳＩＫ术中制瓣时性能及安全性、稳定性优于Ｍｏｒｉａ 组微型角膜刀。ＫＮ－ ５０００ 微型角膜刀还具有良好的易学性和进行ＬＡＳＩＫ角膜板层移植的功能。     

Prevention by rolipram of concanavalin A-induced T-cell-dependent hepatitis in mice

Rolipram is a type IV phosphodiesterase inhibitor endowed with powerful immunomodulatory properties. In this study, we evaluated the effects of this drug on the development of the T-cell-mediated hepatitis inducible in mice by concanavalin A. The results indicated that prophylactic treatment with either 5 or 10 mg/kg rolipram injected intraperitoneally 24 h and 1 h prior to intravenous (i.v.) challenge with 20 mg/kg concanavalin A successfully ameliorated serological and histological signs of liver damage, so that the treated mice showed lower transaminase levels in the plasma and milder mononuclear cell infiltration of the liver as compared to vehicle-treated controls. Moreover, this effect was associated with profound modifications of circulating levels of cytokines released after concanavalin A injection, with the blood levels of interferon-gamma and tumor necrosis factor-alpha being significantly lower and those of interleukin-10 higher than those of the control mice. In particular, the increased blood levels of interleukin-10 might play an important role in the anti-hepatitic effects of rolipram as coadministering this compound with anti-interleukin-10 monoclonal antibody significantly reduced its anti-inflammatory action. These results suggest that rolipram may be useful in the clinical setting for the treatment of cell-mediated immunoinflammatory diseases such as immunoinflammatory hepatitis.     

Prostate cancer old problems and new approaches

Rates of prostate cancer (PCa) have increased so dramatically over the last decade that the age adjusted incidence rate for PCa is now greater than that any other cancer among men in the United States. This review, published as a three part series, provides a state-of-art assessment of the PCa problem in its divergent aspects.Part 1 covers epidemiology, incidence and progression. Several epidemiological studies have demostrated that first degree male relatives of men with PCa are at increased risk of developing the disease. Familial and genetic factors as well as medical, anthropometric, dietary, hormonal and occupational factors involved in PCa are discussed. Postmortem examination of the prostate in men without evidence of PCa documented a high frequency of adenocarcinoma. Latent disease occurred as early as the second decade of life. Although there is no significant difference in incidence between Caucasian and African-American males, high grade prostatic intraepithelial neoplasia (HGPIN) is higher in the latter group. While dietary fat, androgens and certain environmental factors may be determinants for PCa, the exact mechanism of tumorigenesis is still relatively unknown. The current thinking of the role of genomic instability, chromosomal alterations, tumor suppressor genes and the androgen receptor are explored.     

胎儿房室结微血管构筑的扫描电镜观察

用血管铸型结合扫描电镜方法观察了7例胎儿房室结微血管构筑.微动脉反复分支呈树状,行走方式呈波浪形或螺旋形.毛细血管网可分为内外两层:外层纵行为主,以"H"或"Y"形吻合;内层弯曲行走为主,并互相交错吻合.以房室结动脉主干为界,其下方毛细血管密度较大,其上方及前方较小.房室结的上方、前下方和后下方均有微动脉连接毛细血管网.整个结的毛细血管大致可分为结后部上方、下方及前部三个区域.靠毛细血管网外层处可见管径较粗、呈袋状的微静脉.     

Motion artifact reduction with three-point ghost phase cancellation.

A novel method for "ghost" artifact suppression is introduced. It suppresses ghosts induced by motion in any direction, as well as other types of quasi-periodic signal modulation. Because it requires neither special hardware nor intensive data processing, it can be easily implemented on conventional magnetic resonance (MR) imagers. The method is based on the concept of decomposition of a ghosted complex image into a ghost mask and ideal image. A set of deliberately designed acquisitions are used to generate a set of ghosted complex images in which the ghost components are related in a simple manner. With use of equations describing image decomposition and ghost correlation, the ideal image can be calculated pixel by pixel. The ideal image obtained (representing the time-averaged spin-density distribution) is shown to be a truer representation of physical reality than the ghost-free image obtained with ordered phase encoding. In this technique, both interview and intraview effects are taken into account. The technique is also useful in simultaneously suppressing ghosts from multifrequency signal modulations such as respiratory and cardiac motions. The method was successfully tested with three time-interleaved, phase-encoding-order-shifted acquisitions. Experimental results have shown that it is a simple but effective technique.     

经迷路进路听神经瘤术后脑脊液漏的预防及处理

目的　探讨经迷路进路听神经瘤切除术后脑脊液漏发生的影响因素及处理方法。方法1999年以来采用迷路进路或扩大迷路进路听神经瘤切除术 85例 ,前 4 1例采用传统关闭术腔技术 ,后4 4例对关闭技术进行改良 ,分析其脑脊液漏的发生率。发生脑脊液漏者行保守或手术治疗。结果传统关闭技术组中脑脊液漏的发生率为 19 5 % ( 8 4 1) ,改良关闭技术组中脑脊液漏的发生率为 2 3%( 1 4 4 ) ,两组差异有显著性意义 (P =0 0 13)。传统关闭技术组中脑脊液漏多数发生在大型听神经瘤中 ,其发生率随肿瘤增大有上升的趋势。 9例脑脊液漏的患者中 ,3例经保守治疗 ;6例经手术修补成功 ,其中 5例 1次修补成功。结论　改良关闭术腔技术可显著降低经迷路进路听神经瘤切除术后脑脊液漏的发生率 ,手术修补为终止脑脊液漏的有效措施     

抗膀胱癌免疫毒素BDI-1-PEA特异杀伤肿瘤细胞的研究

新近利用抗原处理细胞(APC细胞)处理制备瘤疫效疗较为肯定,认为天然免疫细胞DC细胞瘤疫更有其应用价值.红细胞也是天然免疫细胞.能否用红细胞处理补体调理过的肿瘤细胞制备瘤苗是值得探讨的.有的学者认为红细胞是T细胞活性的调节器,我们的实验有可能为此提供的依据[Arosa FA, Currpharm Des, 2004, 10(27): 191].     

PET在肺癌诊断和分期中的应用

本文介绍正电子发射断层显像(PET)在肺癌诊断和分期中的应用概况，肯定了其临床应用价值。并简要叙述我国PET目前现状及今后展望。PET系大型医疗设备，我国未纳入医疗保险，其发展要根据社会经济发展和病人承受能力，合理布局，有限量地增加。作者指出，加强核医学科人员培训与临床各科医师(包括放射科，肿瘤科，胸外科，放射治疗等)的合作是提高PET临床应用和研究水平的关键因素。