红花栝楼鲨烯合酶基因的克隆及其序列分析

目的克隆红花栝楼鲨烯合酶(squalene synthase,SS)的基因并进行序列分析,为进一步研究葫芦科植物三萜合成通路关键酶SS的正选择位点与功能的关联性分析奠定基础。方法根据绞股蓝与罗汉果SS基因c DNA比对分析的结果,设计SS的5’端简并引物,采用3’RACE扩增红花栝楼SS全长c DNA基因。结果获得红花栝楼SS c DNA全长共1 466个核苷酸,其中包括一个含有1 254个核苷酸的开放读码框,编码417个氨基酸残基。通过NCBI的Blast比对,发现红花栝楼SS基因编码的氨基酸序列与已知植物SS基因编码的氨基酸序列同源性为78%~94%,核苷酸的同源性为74%~93%。结论成功克隆了红花栝楼SS的全长c DNA,为进一步研究红花栝楼SS基因结构、基因表达、基因突变提供了基础,并为葫芦科植物三萜合成通路关键酶SS的正选择位点与功能的关联性分析提供了数据支持。     

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提要：口腔黏膜原发恶性黑色素瘤是一种少见的恶性肿瘤,具有易复发、易转移、预后较差的特点。由于病例数稀少,临床及随访资料匮乏,并且缺少通行的黏膜恶性黑色素瘤分期分级标准。因此,对口腔黏膜原发恶性黑色素瘤还缺乏全面深入的认识。本文通过回顾相关文献,从流行病学、临床、病理、诊断和鉴别诊断以及分类等方面来概述口腔黏膜原发恶性黑色素瘤的特点。     

基于新型扫频光源生物测量仪测量的全角膜屈光力和传统角膜屈光力计算IOL度数的准确性比较

目的：比较基于新型扫频光源生物测量仪测量的全角膜屈光力（TK）和传统角膜屈光力（K）计算人工晶状体（IOL）度数的准确性。方法：前瞻性自身对照研究。收集2021年5—11月在北京大学人民医院眼科因双眼年龄相关性白内障行白内障超声乳化联合衍射型三焦点IOL植入术的患者29例（58 眼）。使用IOLMaster 700扫频光学生物测量仪进行术前眼轴长度、前房深度、中央角膜厚度、晶状体厚度、前后表面角膜屈光力、TK、白到白角膜直径的测量。分别使用K和TK按照目前常用IOL度数计算公式（SRK/T、Haigis、Holladay2及Barrett Universal Ⅱ）及额外新增加的Barrett TK Universal Ⅱ公式计算IOL度数及预测屈光度数。术后1、3个月进行最佳矫正远视力检查及主觉验光。计算绝对预测误差、绝对预测误差均值、绝对预测误差中位数（MedAE）及各个公式预测误差值在±0.25、±0.50、±0.75、±1.00D内所占的百分比。采用Wilcoxon符号秩和检验和McNemar's卡方检验进行数据分析。结果：TK值和K值的差异平均值（TK-K）为0.007D,二者之间的组内相关系数为0.996 （P<0.001）,提示二者之间有良好的一致性。在Haigis和Barrett Universal Ⅱ公式,使用TK值计算的MedAE略小于K值计算的MedAE;在SRK/T和Holladay2公式,使用K值计算的MedAE略小于TK值计算的MedAE。Barrett TK Universal Ⅱ比Barrett Universal Ⅱ公式预测误差值在±0.25、±0.50D内所占的百分比略高,而SRK/T、Haigis及Holladay2公式K值计算比TK值计算预测误差值在±0.25、±0.50D内所占的百分比略高,差异均没有统计学意义。结论：基于新型扫频光源生物测量仪测量的TK值在不同IOL度数计算公式中的IOL度数计算的准确性与K值一致,利用TK值在Barrett TK Universal Ⅱ公式的计算准确性更高。     

Double nuclei in endomyocardial biopsy: A comparative study of the incidence in myocarditis and chronic right ventricular overloading

Summary The incidence of double nuclei in myocarditis and in cases with right ventricular overloading (CRVO) was histopathologically assessed in a minimum of 100 longitudinally cut myocytes in specimens obtained at right ventricular endomyocardial biopsy. In myocarditis, the incidence of double nuclei was shown to be 5.8 ± 1.8 and in CRVO and in normal heart tissue it was seen in 3.0 ± 0.8 and 3.2 ± 0.9% (m±S.D.), respectively, of the population of myocytes. It is concluded that double nuclei result from either the activity or the reparative process of myocarditis and that it is not the expression of chronic right ventricular overloading. It is suggested that quantitative assessment of the frequency of double nuclei is an useful method in the interpretation of myocardial biopsy.This study was supported by a Grant from the Japan Research Promotion Society for Cardiovascular Diseases     

Frequency of erythrocyte pyruvate kinase deficiency in Chinese infants

The incidence of deficiency of the enzyme pyruvate kinase (PK) in Chinese infants was determined. Both the standard assay of erythrocyte pyruvate kinase enzyme activity and a fluorescent screening test (standardized) were used. The results of these two tests were compared. Of 1,159 infant cord blood samples studied, 26 (or 2.2%) had abnormally low levels of PK activity using the screening test, as did 24 of the samples tested by the enzyme assay. The results indicate that the frequency of a defective PK gene in the population of Guangzhou is significantly lower (p less than .05) than the previously reported defective gene frequency of 3.4% in Hong Kong. They also demonstrate the critical importance of standardization of the screening test, if most accurate estimates of gene frequency are to be derived by using this test.     

Measurement of the ratio of glomerular filtration rate to plasma volume from the technetium-99m diethylene triamine pentaacetic acid renogram: comparison with glomerular filtration rate in relation to extracellular fluid volume

Individual kidney glomerular filtration rate (IKGFR) can be measured from the renogram from the rate of uptake of technetium-99m diethylene triamine penta-acetic acid (^99mTc-DTPA). A blood sample is required to derive IKGFR in millilitres per minute, which is then usually normalised to body surface area. We describe a technique which does not require a blood sample, is already normalised for plasma volume and uses the robust Patlak plot for measuring renal uptake. The rate of kidney uptake, dR(t)ldt, at time = 0, as a fraction of the injected dose, is equal to the fraction of the plasma volume (PV) filtered per minute, i.e. IKGFR/PV. The gradient dR(0)/dt cannot be accurately measured directly but is equal to [ · LV(0)], where is the renal uptake constant (proportional to IKGFR) and LV is the count rate over a left ventricular ROI. LV(0) was obtained by extrapolation of LV(t), while a is the slope of the Patlak plot up to 3 min. GFR/PV (i.e. right plus left kidneys) in patients with normal renal function was about 0.04 min^–1, as would be expected from normal values of GFR (120 ml/min) and plasma volume (3 l). GFR/PV correlated significantly with the ratio of GFR to extracellular fluid volume (ECV), measured from the terminal exponential of the plasma clearance curve (GFR/PV = 3.2.GFR/ECV + 5.3 ml/min/1 [r = 0.82,n = 82]). GFR/PV (r = 0.74) and GFR/ECV (r = 0.82) both correlated inversely and non-linearly with plasma creatinine in 43 studies where the measurement was made within 1 week of the^99mTcDTPA study. They also correlated significantly with the plasma cyclosporin trough level in 14 patients with dermatomyositis on the 30 occasions when this measurement was made within 1 week of the renogram (r = –0.38,P < 0.05 for GFR/PV andr = –0.77,P < 0.001 for GFR/ECV). The ratio of GFR/PV to GFR/ECV is the ratio of extracellular fluid volume to plasma volume, and this was 4.0 (SD 0.99). We conclude that both GFR/PV and GFR/ECV can be easily measured with^99mTc-DTPA and are physiologically valid expressions of GFR. Although GFR/PV and GFR/ECV correlate with each other, the question is raised as to which of the two fluid volumes is the most appropriate for normalising GFR. Correspondence to: A.M. Peters     

嗜肺军团菌血清10型致军团病爆发流行并分离培养成功

１９９２年２～３月，北京市郊某宾馆发生了一起上呼吸道感染流行。流行病学调查及细菌学检查证明，这是一起嗜肺军团菌血清１０型（Ｌｐ１０）引起的宾馆军团病爆发流行，感染率为２４．３２入（９／３７），患病率为１３．５１％（５／３７）。由Ｌｐ１０引起的军团病爆发流行在世界上属首次报道，而Ｌｐ１０分离培养成功在国内尚属首次。     

急性低压缺氧对人体血清内源性类洋地黄物质含量的影响

用放射免疫法测定了16名健康飞行人员清晨和急性低压缺氧后（10：00）的血清内源性类洋地黄物质（EDLS）含量，并以16名健康地面人员相应时间的测定作对照。结果发现，实验组与对照组清晨血清EDLS含量分别为0．63±0．07与0．60±0．07ng／ml，两组相比，光显著性差异（P＞0．05）。实验组急性低压缺氧后，血清中的EDLS含量0．63±0．10ng／ml，与相应测定的对照组0．52±0．10ng／ml相比，有显著性差异（P＜0．01）。结果提示，急性中度缺氧能增加EDLS分泌、而正常人血清EDLS含量有明显生理性波动。急性中度缺氧后，血清中EDL含量的增加，可能是一种保护性的应激反应。     

Distribution of normal and abnormal fluid collections in the glenohumeral joint: Implications for MR arthrography

Although magnetic resonance (MR) images of the glenohumeral joint frequently demonstrate intraarticular fluid, no specific criteria have, to the authors' knowledge, been published that allow accurate assessment of the amount of fluid present. Also, despite the increasing use of MR arthrography of the shoulder, the optimal amount of intra-articular fluid that should be used with this technique has not been determined. The authors progressively distended the glenohumeral joint in six cadaveric shoulder specimens with a dilute gadopentetate dimeglumine solution and obtained MR images after injection of 2, 5, 10, 15, and 20 mL of the solution. The pattern of fluid distribution was evaluated, and these results were then used to estimate the amount of fluid that was present in the glenohumeral joint on MR images of 20 shoulders obtained in 12 asymptomatic volunteers. In 14 of these shoulders, intraarticular fluid was present; however, in none was more than 2 mL evident. Results of the cadaveric study also indicated that 15 mL of intraarticular fluid appears to be the optimal amount for MR arthrography.     

乳腺良恶性病变组织c-met蛋白和转化生长因子α的表达及意义

应用免疫组化法测定５０例乳腺癌和１２例乳腺良性病变组织中ｃｍｅｔ蛋白及转化生长因子α（ＴＧＦα）的表达。结果：乳腺癌组织中ｃｍｅｔ蛋白及ＴＧＦα表达阳性率分别为２６．０％和４２．０％,乳腺良性病变组织中两者表达阳性率分别为８．３％和２５．０％;组织学分级为Ⅰ级,雌激素受体（ＥＲ）、孕激素受体（ＰＲ）及癌胚抗原（ＣＥＡ）为阴性的病例中,ｃｍｅｔ蛋白及ＴＧＦα表达阳性率明显低于组织学分级Ⅲ级,ＥＲ、ＰＲ及ＣＥＡ为阳性者（ｃｍｅｔ及ＰＲＰ＜０．０１;ＴＧＦα、ＰＲ和ＣＥＡＰ＜０．０５;余Ｐ＞０．０５）。本实验结果提示：ｃｍｅｔ蛋白及ＴＧＦα表达可能与乳腺癌发生发展及体机内分泌状态有较密切关系