Assessment of the mutagenicity of dichloroacetic acid in lacI transgenic B6C3F1 mouse liver

Dichloroacetic acid (DCA) is a chlorination byproduct found in finished drinking water. When administered in drinking water this chemical has been shown to produce hepatocellular adenomas and carcinomas in B6C3F1 mice over the animal's lifetime. In this study, we investigated whether mutant frequencies were increased in mouse liver using treatment protocols that yielded significant tumor induction. DCA was administered continuously at either 1.0 or 3.5 g/l in drinking water to male transgenic B6C3F1 mice harboring the bacterial lacI gene. Groups of five or six animals were killed at 4, 10 or 60 weeks and livers removed. At both 4 and 10 weeks of treatment, there was no significant difference in mutant frequency between the treated and control animals at either dose level. At 60 weeks, mice treated with 1.0 g/l DCA showed a 1.3-fold increase in mutant frequency over concurrent controls (P = 0.05). Mice treated with 3.5 g/l DCA for 60 weeks had a 2.3-fold increase in mutant frequency over the concurrent controls (P = 0.002). The mutation spectrum recovered from mice treated with 3.5 g/l DCA for 60 weeks contained G:C-->A:T transitions (32.79%) and G:C-->T:A transversions (21.31%). In contrast, G:C-->A:T transitions comprised 53.19% of the recovered mutants among control animals. Although only 19.15% of mutations among the controls were at T:A sites, 32.79% of the mutations from DCA-treated animals were at T:A sites. This is consistent with the previous observation that the proportion of mutations at T:A sites in codon 61 of the H-ras gene was increased in DCA-induced liver tumors in B6C3F1 mice. The present study demonstrates DCA-associated mutagenicity in the mouse liver under conditions in which DCA produces hepatic tumors.      

Fatty acid balance studies in term infants fed formula milk containing long-chain polyunsaturated fatty acids

Long-chain polyunsaturated fatty acids (LCP) are thought to be required for optimal nervous system development in the newborn. A commercial milk formula containing LCP (Aptamil-LCP) with a fatty acid profile closely resembling breast milk, has recently been introduced for term infants. The absorption of fatty acids in term infants was examined in a double-blind randomized controlled trial comparing Aptamil-LCP ( n = 20) and standard Aptamil ( n = 20). Formula-fed newborn infants were studied from birth for 14 d. Fat balances (3 d) were performed from d 10. A 3-d stool collection was performed from d 10 in a parallel breastfed group ( n = 21). Plasma samples were taken on d 6. Median fat excretion (mg kg⁻¹) was 897.1, 615.0 and 355.2 with Aptamil, Aptamil-LCP and breastfeeding, respectively. The median total fat absorption coefficient in Aptamil-LCP-fed infants was higher than in those fed standard Aptamil ( p < 0:01). These findings were accounted for by differences in the excretion and absorption of long-chain saturated fatty acids (C14:0, C16:0 and C18:0). Higher fat excretion was associated with bulkier and firmer stools. Only trace amounts of LCP were detected in the stools of all groups. This accounted for less than 4% of dietary intake in Aptamil-LCP-fed infants. No differences in the utilization of LCP from Aptamil-LCP and breast milk feeding were apparent. Plasma phospholipid fatty acid composition data reflected differences in dietary LCP intake. Thus, PL LCP levels were highest in the breastfed infants and lowest in the Aptamil-fed infants, with values for the Aptamil-LCP-fed group falling in between.     

安徽省2007～2008年志贺氏菌流行株菌型分布及脉冲场分子分型

目的了解安徽省志贺氏菌的流行菌型,并建立脉冲场凝胶电泳（PFGE）分子分型方法,为菌痢防控提供理论基础。方法对22株志贺氏菌进行血清分型、药物敏感试验和PFGE试验。结果22株志贺氏菌血清分型：B群19株,占总数86.5%;C群1株,占总数的4.5%;D群2株,占总数的9.0%。成功建立了菌痢的PFGE分子分型方法,并将我省22株流行株分为若干带型。试验结果进一步作聚类分析。结论安徽省菌痢流行株以福氏为主;安徽省PFGE分子分型方法和初步带型数据库对提高细菌检测水平有一定意义。     

超声对甲状腺术后瘢痕组织的诊断应用

甲状腺术后瘢痕组织是甲状腺局部分切除术后由于手术方式及缝线填充而形成的组织,甲状腺术后瘢痕组织形成及其发生发展过程同一般的组织损伤修复病理过程一样,为渐进老化阶段的结缔组织,其内小血管稀少,胶原纤维增多[1]。由于甲状腺术后瘢痕组织其质地较硬,活动性差,超声声像图上表现缺乏典型特征,与癌灶极其相似,因此鉴别较困难。本文将介绍超声对于甲状腺术后的随诊应用,分析甲状腺术后瘢痕组织的超声检查特点并着重介绍超声动态观察甲状腺术后瘢痕组织的应用及其发展前景。     

吡柔比星(THP)膀胱灌注预防腺性膀胱炎术后复发的疗效观察

目的 评价吡柔比星(THP)膀胱灌注预防腺性膀胱炎术后复发的疗效。方法 对30例腺性膀胱炎患者行经尿道汽化电切术,术后定期应用THP(40mg/50ml)膀胱内灌注化疗。结果 30例患者随访5～20个月,平均14.5个月,3例复发(10％)。未见有全身性药物不良反应,仅2例血白细胞降至3000个/ml。结论THP膀胱灌注预防腺性膀胱炎术后复发疗效满意,病人耐受性好,副作用小。     

舌黏膜尿道成形治疗尿道狭窄的初步报告

目的:探讨舌黏膜补片法尿道成形治疗尿道狭窄的疗效。方法:采用舌黏膜尿道成形治疗尿道狭窄14例。尿道狭窄段3.5~14cm,平均6.2cm;术前耻骨上膀胱造瘘8例,余6例排尿均较为困难,最大尿流率2.5~5.5ml/s,平均3.8ml/s。结果:术后随访2~8个月,1例因伤口感染致尿道皮肤瘘,余患者均排尿通畅,最大尿流率增至22~51ml/s,平均29.6ml/s。结论:舌黏膜具有取材方便、对患者创伤小、抗感染力强等特点,是一种较好的尿道替代物,尤其适合尿道狭窄段<6cm的患者。     

直视下尿道内切开术治疗尿道狭窄20年经验总结

目的 总结直视下尿道内切开术(direct vision internal urethrotomy,DVIU)治疗尿道狭窄的经验.方法 回顾性分析1990年6月至2010年6月20年间DVIU治疗尿道狭窄或闭锁患者361的临床资料.年龄16～72岁,平均38岁.病程3～78个月,平均16个月.狭窄或闭锁长度0.2～2.0 cm,平均1.1 cm.狭窄长度≤1.0 cm 238例,其中≤0.5 cm 63例(组1),0.6～1.0 cm 175例(组2),瘢痕厚度≤1.0 cm 148例,＞1.0 cm 90例;狭窄长度1.1～2.0 cm 123例,其中1.1～1.5cm 85例(组3),1.6～2.0 cm 38例(组4),瘢痕厚度≤1.0 cm 44例,＞1.0 cm 79例.结果 361例中手术失败3例.320例获随访,随访时间12～120个月,平均42个月.因狭窄复发而接受开放手术174例(54.4%),4组中转开放手术率分别为3.3%、49.7%、83.3%和97.1%.狭窄长度≤1.0cm者获随访207例,其中瘢痕厚度≤1.0 cm转开放手术27.2%(37/136),瘢痕厚度＞1.0 cm转开放手术60.6%(43/71).狭窄长度＞1.0 cm者获随访113例,其中瘢痕厚度≤1.0 cm转开放手术78.6%(33/42),瘢痕厚度＞1.0 cm转开放手术84.5%(60/71).结论 当尿道狭窄长度≤0.5 cm时,DVIU术后转开放手术的比例明显减少;狭窄长度≤1.0 cm,瘢痕厚度≤1.0 cm者,DVIU也可获较好疗效.

Abstract：

Objective To summarize the experience and evaluate the efficacy of treatment of urethral stricture using direct visual internal urethrotomy (DVIU).Methods The clinical data of 361 patients (age range 16 -72 years, mean age 38 years) with urethral stricture who underwent urethrotomy from 1990 to 2010 was retrospectively analyzed.The disease course ranged from three months to 78 months with a mean of 16 months.The stricture length ranged from 0.2 to 2.0 cm (mean 1.1 cm).Stricture length was split into four main groups:stricture length≤0.5 cm in 63 (group 1 ), stricture length ranging between 0.6 and 1.0 cm in 175 ( group 2), stricture length ranging between 1.0 and 1.5 cm in 85 ( group 3 ) , and stricture length ranging between 1.6 and 2.0 cm in 38 ( Group 4).Of the 238 patients with length less than 1.0 cm there were 148 who's scar thickness were less than 1.0 cm, and 90 who's scar thickness were greater than 1.0 cm.Of the 123 patients with length less than 2.0 cm there were 69 who's scar thickness was less than 1.0 cm, and 54 who's scar thickness was greater than 1.0 cm.Results Three patients with DVIU failed because of long occlusion and false passage.Three hundred and twenty patients were followed-up from 12 to 120 months (mean:42).Re-openiag procedures were performed on 174 patients (54.4%) due to recurrence.The re-openiag procedure rate was 3.3%, 49.7%, 83.3% and 97.1% in Group1, Group2,Group3 and Group4, respectively.On the basis of scar thickness, of the 207 patients with stricture length less than 1.0 cm, 38 of 136 patients (27.9%) with scar thickness less than 1.0 cm underwent opening operation, and 43 of 71 patients (60.6%) with scar thickness more than 1.0 cm underwent opening operation.One hundred and thirteen patients with stricture length more than 1.0 cm, 33 of 42 patients (78.6%) with scar thickness less than 1.0 cm underwent opening operation, and 60 of 71 patients (84.5%) with scar thickness more than 1.0 cm underwent opening operation.Conclusions Good efficacy can be achieved in patients whose urethral stricture length is less than 0.5cm or whose stricture length and scar thickness is less than 1.0 cm using DVIU.     

Meta-analysis of retrojugular versus antejugular approach for carotid endarterectomy

Introduction

The retrojugular approach for carotid endarterectomy (CEA) has been reported to have the advantages of shorter operative time and ease of dissection, especially in high carotid lesions. Controversial opinion exists with regard to its safety and benefits over the conventional antejugular approach.

Methods

A systematic review of electronic information sources was conducted to identify studies comparing outcomes of CEA performed with the retrojugular and antejugular approach. Synthesis of summary statistics was undertaken and fixed or random effects models were applied to combine outcome data.

Findings

A total of 6 studies reporting on a total of 740 CEAs (retrojugular approach: 333 patients; antejugular approach: 407 patients) entered our meta-analysis models. The retrojugular approach was found to be associated with a higher incidence of laryngeal nerve damage (odds ratio [OR]: 3.21, 95% confidence interval [CI]: 1.46–7.07). No significant differences in the incidence of hypoglossal or accessory nerve damage were identified between the retrojugular and antejugular approach groups (OR: 1.09 and 11.51, 95% CI: 0.31–3.80 and 0.59–225.43). Cranial nerve damage persisting during the follow-up period was similar between the groups (OR: 2.96, 95% CI: 0.79–11.13). Perioperative stroke and mortality rates did not differ in patients treated with the retrojugular or antejugular approach (OR: 1.26 and 1.28, 95% CI: 0.31–5.21 and 0.25–6.50).

Conclusions

Currently, there is no conclusive evidence to favour one approach over the other. Proof from a well designed randomised trial would help determine the role and benefits of the retrojugular approach in CEA.     

柠檬酸对分化型甲状腺癌患者首次131I治疗后唾液腺功能的保护作用

目的：探讨柠檬酸对术后首次行¹³¹I治疗（简称清甲治疗）的分化型甲状腺癌（DTC）患者唾液腺功能的影响,阐明柠檬酸对¹³¹I治疗的甲状腺癌患者唾液腺功能的保护作用。方法：经患者知情同意,随机选择准备首次行¹³¹I治疗的68例甲状腺乳头状癌患者,随机分为对照组和柠檬酸组,每组34例。对照组患者无特殊准备,柠檬酸组患者于¹³¹I治疗前1周及治疗后3周内每天含柠檬酸1 min（0.2 g/次）后吐出。2组患者分别于¹³¹I治疗前24 h及¹³¹I治疗后3个月行2次^99mTcO^4-唾液腺显像检查,计算第15分钟摄取指数（15 min UI）和排泌分数（SR）,评估唾液腺功能。结果：与¹³¹I治疗前比较,对照组患者¹³¹I治疗后右侧腮腺和双侧颌下腺15 min UI差异无统计学意义（P>0.05）,左侧腮腺15 min UI降低（P<0.05）;与¹³¹I治疗前比较,柠檬酸组患者¹³¹I治疗后双侧腮腺及双侧颌下腺15 min UI差异无统计学意义（P>0.05）;与对照组比较,柠檬酸组患者¹³¹I治疗前后双侧腮腺和双侧颌下腺15 min UI差异均无统计学意义（P>0.05）。与¹³¹I治疗前比较,对照组患者双侧腮腺治疗后SR降低（P<0.05）,双侧颌下腺SR差异无统计学意义（P>0.05）,柠檬酸组患者双侧腮腺和双侧颌下腺治疗后SR差异无统计学意义（P>0.05）;与对照组¹³¹I治疗后比较,柠檬酸组患者双侧腮腺SR升高（P<0.05）,双侧颌下腺SR差异无统计学意义（P>0.05）。结论：DTC患者术后首次¹³¹I治疗后唾液腺排泌功能可能受损,短期口含柠檬酸对唾液腺具有保护作用,可以减轻唾液腺的放射性损伤。     

Normal rotator cuff: MR imaging with conventional and fat-suppression techniques

The signal intensity and morphologic characteristics of the rotator cuff and surrounding structures at magnetic resonance (MR) imaging were investigated with five pulse sequences in 15 asymptomatic subjects. In all subjects, a focal region of relative increased signal intensity corresponding to the critical zone was observed in the supraspinatus tendon just proximal to its insertion. Soft-tissue signal intensity (isointense with muscle) was also located between the supraspinatus tendon and underlying joint capsule, interposed between the conjoined leaves of the supraspinatus and infraspinatus tendons, and superolateral to the conjoined cuff tendon, near its insertion. These regions were most conspicuous and most clearly defined with fat-suppression imaging. Small amounts of fluid were observed within the joint space and its recesses, the bicipital tendon sheath, and the subacromial-subdeltoid bursa. These and other MR imaging findings of this study previously have been regarded as indicative of rotator cuff abnormalities. These results will help refine the criteria for diagnosis of rotator cuff disorders with MR imaging.