Prediction of improvement of ventricular function after revascularization: 18F-fluorodeoxyglucose single-photon emission computed tomography vs low-dose dobutamine echocardiography

AIMS: To compare assessment of myocardial flow and glucose metabolismby single-photon emission computed tomography (SPECT) with low-dosedobutamine echocardiography in predicting improvement in regionaland global left ventricular function after coronary artery bypassgrafting. METHODS AND RESULTS: Thirty patients with regional wall motion abnormalities (meanejection fraction 32±19%) were studied with low-dosedobutamine echocardiography (5 and 10 µg . kg^–1.min^–1) and thallium-201/ ¹⁸F-fluorodeoxyglucose(FDG) SPECTprior to surgery. For comparative analysis, a 13-segment modelwas used. Postoperative improvement was predicted if the echocardiogramshowed that wall motion abnormalities were reversible duringthe dobutamine infusion and there was normal perfusion or relativelyincreased FDG uptake in perfusion defects (mismatch) in dyssynergicsegments on SPECT. After surgery, ventricular function was reassessed.An echocardiogram was taken at the 3 month follow-up with thepatient at rest. Regional wall motion had improved in 62/168(37%) revascularized segments. In predicting functional outcome,low-dose dobutamine echocardiography reached a sensitivity of89% and a specificity of 82%, with a positive predictive valueof 74% and a negative predictive value of 93%, whereas for thallium-201/FDGSPECT these values were 84%, 86%, 78% and 90%, respectively.In patients with more than two viable segments on either technique,the wall motion score index, a surrogate of global ventricularfunction, improved significantly. CONCLUSION: For the optimal prediction of functional out-come, combinedassessment of flow and FDG imaging is needed. Both thallium-201/FDGSPECT and low-dose dobutamine echocardiography appear comparableand similarly accurate in predicting improvement of left ventricularfunction after surgical revascularization.     

European study on epidemiology and the management of HCV in the haemodialysis population--Part 1: centre policy

Haemodialysis patients are known to be at risk of infection of Hepatitis C Virus (HCV) through nosocomial spread. This paper presents the first part of a study on epidemiology and management of HCV, in a haemodialysis population, conducted by the EDTNA/ERCA Research Board. Data on HCV management and infection control procedures was collected from 136 European centres using an electronic questionnaire. The study identifies a number of possible risk factors for transmission of the virus: failing to disinfect devices between patients, sharing of single-use vials to prepare drugs or infusions for different patients, inadequate sterilisation or cleaning of machines between dialysis sessions, unsatisfactory environmental cleaning and distance less than one metre between chairs.     

Ultrasound evaluation of cortical brain development in fetuses with intrauterine growth restriction

Objective: We evaluated the ultrasound appearance of brain volume and cortical development in fetuses with early growth restriction and placental insufficiency.

Methods: We examined a cohort of 20 fetuses with severe intrauterine growth restriction (IUGR) and evidence of placental insufficiency by three-dimensional (3D) ultrasound between 24 and 34 weeks. We graded cortical development and measured the supratentorial intracranial volume. The cortical grading and volume were compared to data obtained from a reference population of 28 adequate for gestational age (AGA) fetuses.

Results: Ultrasound examinations were performed in 20 fetuses with IUGR. The biometry and brain volume were significantly reduced in IUGR fetuses. There was evidence of accelerated cortical development in IUGR fetuses.

Conclusion: This study confirms that the smaller brain volume in IUGR fetuses, with normal or accelerated cortical maturation as previously depicted with postnatal MRI examination, can be demonstrated by prenatal 3D ultrasound.     

RP-HPLC法测定β-司他夫定的有关物质

目的:建立了β-司他夫定原料有关物质的RP-HPLC测定方法和水解破坏制备系统适用性试验溶液方法。方法:采用Agilent 1100型高效液相色谱仪,使用SUPELCOSIL LC-18-DB(4.6 mm×250 mm,5μm)色谱柱,以0.01 mol·L-1醋酸铵溶液-乙腈(96.5∶3.5)和0.01 mol·L-1醋酸铵溶液-乙腈(75∶25)为流动相,梯度洗脱,检测波长254 nm,柱温25℃。结果:β-司他夫定和4种已知杂质及其他未知杂质均能达到有效分离;经水解破坏产生的α-司他夫定与β-司他夫定的分离度均达2.8;β-司他夫定、胸腺嘧啶、β-胸苷与5-O’-苯甲酰-司他夫定线性范围分别为0.51~26μg·m L-1(r=1.000)、0.13~27μg·m L-1(r=1.000)、0.50~25μg·m L-1(r=1.000)、1.7~6.3μg·m L-1(r=1.000),已知杂质胸腺嘧啶、β-胸苷与5-O’-苯甲酰-司他夫定的平均加样回收率(n=9)分别为102.8%(RSD=1.5%)、100.6%(RSD=0.9%)、101.9%(RSD=2.1%);β-司他夫定与3种已知杂质的最小检出量均在2.5 ng以下;经水解破坏制备的系统适用性溶液的重复性良好;供试品溶液在4℃下的30 h内基本稳定。结论:本方法灵敏、准确、可靠,专属性强,可用于β-司他夫定原料的有关物质测定。     

Comparison of effects on systolic and diastolic left ventricular function of nebivolol versus atenolol in patients with uncomplicated essential hypertension

This was a double-blind, randomized, prospective study comparing the effects of nebivolol and atenolol on systolic diastolic left ventricular function in patients with essential hypertension. A significant difference was seen in stroke volume between these 2 drugs. The blood pressure lowering effect of atenolol was strongly related to cardiac output and heart rate reduction. The blood pressure lowering effect of nebivolol was related to a reduction in peripheral resistance and an increase in stroke volume with preservation of cardiac output. This preservation of cardiac output, together with a reduced peripheral resistance, may be potentially important in treating heart failure.     

幽门螺杆菌感染对胃黏膜病理变化的影响

背景：幽门螺杆菌(H．pylori)感染已被公认为慢性胃炎和消化性溃疡的重要危险因素，根除H．pylori能加速消化性溃疡的愈合，但其对胃黏膜病理变化的影响尚有待进一步探索。目的：了解根除H．pylori对慢性胃炎胃黏膜病理变化和癌前状态的影响。方法：采用多中心随机对照临床试验和回顾性队列研究，样本选自胃癌高发区：上海郊区的金山区和奉贤区。共纳入360例经内镜检查证实有H．pylori感染的慢性胃炎伴或不伴十二指肠溃疡患者，随机分为两组。治疗组用三联疗法(质子泵抑制剂或Hz受体阻滞剂加两种抗生素)治疗，对照组单纯慢性胃炎患者予西沙必利、十二指肠溃疡患者予西米替丁治疗。在第1年和第4年末随访胃镜，根据H．pylori是否根除将患者分为两组：H．pylori阳性组和H．pylori阴性组。所有胃黏膜活检标本由两位病理科医师统一复读。结果：至第4年末，有120例患者完成全部随访，其中H．pylori持续根除组54例，阳转组5例；H．pylori持续未根除组45例，阴转组16例。持续根除组第1年随访时，活动性炎症比例减少(P＜O．05)；第4年随访时，慢性炎症和肠化程度以及活动性炎症比例减少(P＜O．05)。持续未根除组第1年随访时，慢性炎症程度增加(P＜O．05)；第4年随访时，慢性炎症和肠化程度以及活动性炎症比例增加(P＜O．05)，萎缩程度较第1年随访时增加(P＜O．05)。结论：根除H．pylori可以减轻慢性胃炎的炎症程度，防止肠化的发生和发展。     

Studies on isolated rat adrenal cells. I. Continuous flow and batch incubation.

A procedure for the continuous flow incubation of isolated adrenal cells is described. In this way the advantages of continuous flow incubations of adrenal tissue are combined with those of isolated adrenal cells. Suspensions of isolated adrenal cells were prepared by a modification of the collagenase method. A sigmoid dose-response curve was obtained when these cells were incubated with ACTH in batch incubations. Under these conditions (in the presence of 1 mU ACTH/ml) the corticosterone production rate remained constant during at least 240 min. This production rate was linearly related to the number of cells. Pre-incubation of the cells during 3 h resulted in an increased response to ACTH. In continuous flow incubations without ACTH the corticosterone production was negligible. With 100 mu U ACTH/ml corticosterone production increased sharply after a short lag period. A maximum was reached after 60-75 min followed by a slow decrease. Cells pre-incubated in the continuous flow apparatus had a slightly diminished ACTH response without loss of affinity to ACTH. The continuous flow incubation of isolated adrenal cells offers new possibilities for the dynamic study of steroid biosynthesis in vitro. The method may also be valuable to study processes in a wide variety of other tissues.     

Human fetal and cord serum thyroid hormones: developmental trends and interrelationships

Thyroid hormone is essential for fetal and neonatal development in particular of the brain, but little is known about regulation of fetal thyroid hormone levels throughout human gestation. The purpose of this study was to clarify developmental trends and interrelationships among T(4), free T(4) (FT4), thyroxine-binding globulin (TBG), TSH, T(3), rT(3), and T(4) sulfate (T4S) levels in cord and fetal blood sera (n = 639, 15-42 wk gestation) and correlate infant levels (23-42 wk gestation) to maternal values (n = 428, 16-45 yr) and those of nonpregnant women (n = 233, 16-46 yr). In cord and fetal serum, T(4), T(3), and TBG levels increase with gestation until term; TSH, FT4, T4S, and rT(3) levels increase and peak in the late second/early third trimester and then decline to term; T(4)/TBG ratios increase until late second trimester and plateau to term. Term cord sera TSH, TBG, and all iodothyronine levels, except T(3), are higher than nonpregnant women. In the third trimester, cord serum FT4, TSH, rT(3), and T4S levels are also higher than corresponding maternal levels, but T(4), T(3), and TBG levels are lower than maternal values. The late second/early third trimester is a critical transition period in fetal thyroid hormone metabolism, which may be interrupted by preterm birth and contribute to postnatal thyroid dysfunction.     

Differential expression of sulfotransferase enzymes involved in thyroid hormone metabolism during human placental development.

Thyroid hormone is essential for normal human development, and disruption of thyroid hormone homeostasis at critical developmental stages can result in severe and often long-term effects on crucial organs such as the brain and lungs. Numerous factors control the bioavailability of receptor active thyroid hormone T(3). Sulfation, catalyzed by sulfotransferase enzymes (SULTs), is an important pathway of thyroid hormone metabolism by which T(4) is irreversibly converted to inactive reverse T(3) rather than active T(3). The human fetus and neonate have high levels of circulating sulfated iodothyronines, although the source of these is not clear. The placenta forms the link between the fetus and its mother and is involved in transfer of thyroid hormone early in pregnancy, although its capacity for sulfation is unknown. We therefore examined expression of the SULTs involved in iodothyronine metabolism during human placental development. SULT activity was measured in human placental cotyledon and membranes (amnion, chorion, and decidua basalis) from 13-42 wk of gestation, and Western blot analysis was employed to verify enzyme activity data. Phenol and catecholamine sulfotransferases were expressed at the highest levels and were generally higher in the villous than membranous tissues. SULT1A1 activity showed significant correlation with sulfation of 3,3'-T(2), suggesting that this enzyme is primarily responsible for placental T(2) sulfation. Estrogen sulfotransferase was present at extremely low levels during early pregnancy, although in mid- and late gestation increased expression in the (predominantly maternal-derived) decidual component of the placenta was observed. Hydroxysteroid sulfotransferase, T(3), reverse T(3), and T(4) SULT activities were also low in all tissues examined, and expression of SULTs 1B1 and 1C2 were essentially undetectable by Western blot analysis. The results highlight a tissue-specific regulation of SULT expression during placental development, demonstrate very low sulfation of iodothyronines suggesting that the placenta is not a major source of circulating sulfated iodothyronines in the fetus.