Experimental evaluation of ten clinically used arterial prostheses

The arterial grafts currently in use are classified into five basic categories; 10 different commercially available prostheses were chosen to represent these categories. The Vascutek and Bionit are made from knitted Dacron and have medium porosity, requiring preclotting by the surgeon. The DeBakey Soft Woven and Plasma TFE grafts are made from woven Dacron and have low porosity, not requiring preclotting under most circumstances. Also studied were woven and knitted grafts with leakage resistance referred to as impervious Dacron grafts: the Vascutek Gelseal, the Bard Albumin Coated DeBakey Vasculour II, the Microvel with Hemashield, and the albumin saturated, autoclaved DeBakey Soft Woven graft. Gore-Tex and Impra are expanded polytetrafluoroethylene grafts which do not require preclotting. For each type, five grafts 6 cm long and 8 mm in diameter were implanted in the descending thoracic aorta of healthy adult dogs for 16 weeks. The physical characteristics, biocompatibility, and healing patterns varied according to the structure and treatment of the grafts. Pretreatment with biomaterials during manufacture is quite effective in preventing transinterstices blood loss during implantation, but results in altered physical qualities, increased thrombogenicity and delayed healing in comparison to the effects of preclotting with autogenous blood at the time of implantation.     

Low-grade carotid artery stenosis is associated with progression of brain atrophy and cognitive decline. The SMART-MR study

Asymptomatic low-grade carotid artery stenosis (LGCS) is a common finding in patients with manifest arterial disease, however its relationship with brain MRI changes and cognitive decline is unclear. We included 902 patients (58 ± 10 years; 81% male) enrolled in the Second Manifestations of Arterial Disease – Magnetic Resonance (SMART-MR) study without a history of cerebrovascular disease. LGCS was defined as 1–49% stenosis on baseline carotid ultrasound, whereas no LGCS (reference category) was defined as absence of carotid plaque. Brain and white matter hyperintensity (WMH) volumes and cognitive function were measured at baseline and after 4 (n = 480) and 12 years (n = 222) of follow-up. Using linear mixed-effects models, we investigated associations of LGCS with progression of brain atrophy, WMH, and cognitive decline. LGCS was associated with greater progression of global brain atrophy (estimate −0.03; 95%CI, −0.06 to −0.01; p = 0.002), and a greater decline in executive functioning (estimate −0.02; 95%CI, −0.031 to −0.01; p < 0.001) and memory (estimate −0.012; 95%CI, −0.02 to −0.001; p = 0.032), independent of demographics, cardiovascular risk factors, and incident brain infarcts on MRI. No association was observed between LGCS and progression of WMH. Our results indicate that LGCS may represent an early marker of greater future brain atrophy and cognitive decline.     

胚胎嗅鞘细胞再移植治疗晚期脊髓损伤1例

目的:对晚期脊髓损伤患者开展嗅鞘细胞再移植治疗,探讨其对神经功能的继续改善效果。方法:①患者男性,27岁,哈萨克斯坦籍,2001年9月20日遭霰弹枪击急诊手术后,双下肢不能运动及感觉消失,尿便失禁,右下肢阵发性钝痛。诊断为陈旧性完全性脊髓损伤(T12),美国脊髓损伤协会标准脊髓功能分级为A级。2002年9月30日第1次行脊髓胚胎嗅鞘细胞移植术,2007年2月5日行第2次脊髓胚胎嗅鞘细胞移植术。治疗方案患者知情同意。②取4个月流产胚胎(孕妇及其家属均知情同意)的嗅球,消化成单个嗅鞘细胞后培养2周,细胞浓度约2×1010L-1。于患者相应脊髓损伤上端(平T11椎体)做1个锁孔,直径约3cm,在脊髓损伤部位与正常脊髓交界处沿中线于无血管区,分两点用4.5号细针共注入100μL(第1次手术)、50μL(第2次手术)嗅鞘细胞悬液,细胞数均为1×106个。第2次移植术前进行供、受体细胞HLA配型,术后口服FK506胶囊2mg,2次/d,共42d。结果:①第1次术后3个月,排尿能控制6h,双足运动功能改善,性功能改善,阴茎勃起功能改善,疼痛减轻。②第2次术后10d,双下肢双足皮肤泌汗功能改善,右下肢疼痛减轻,腹部皮肤感觉稍有好转,针刺觉左侧由术前T10皮节消失好转至T10减退。较第2次移植前椎旁躯体感觉诱发电位有所改善,双侧椎旁电位从T10下降到T12。结论:胚胎嗅鞘细胞二次移植能继续改善晚期脊髓损伤患者的神经功能。但移植的细胞数量、容积、注射点位置等需深入探讨。     

The LIFESTYLE study: costs and effects of a structured lifestyle program in overweight and obese subfertile women to reduce the need for fertility treatment and improve reproductive outcome. A randomised controlled trial

Background

In the Netherlands, 30% of subfertile women are overweight or obese, and at present there is no agreement on fertility care for them. Data from observational and small intervention studies suggest that reduction of weight will increase the chances of conception, decrease pregnancy complications and improve perinatal outcome, but this has not been confirmed in randomised controlled trials. This study will assess the cost and effects of a six-months structured lifestyle program aiming at weight reduction followed by conventional fertility care (intervention group) as compared to conventional fertility care only (control group) in overweight and obese subfertile women. We hypothesize that the intervention will decrease the need for fertility treatment, diminish overweight-related pregnancy complications, and will improve perinatal outcome.

Methods/Design

Multicenter randomised controlled trial in subfertile women (age 18-39 year) with a body mass index between 29 and 40 kg/m². Exclusion criteria are azoospermia, use of donor semen, severe endometriosis, premature ovarian failure, endocrinopathies or pre-existent hypertensive disorders. In the intervention group the aim is a weight loss of at least 5% to10% in a six-month period, to be achieved by the combination of a diet, increase of physical activity and behavioural modification. After six months, in case no conception has been achieved, these patients will start fertility treatment according to the Dutch fertility guidelines. In the control group treatment will be started according to Dutch fertility guidelines, independently of the patient's weight.

Outcome measures and analysis

The primary outcome measure is a healthy singleton born after at least 37 weeks of gestation after vaginal delivery. Secondary outcome parameters including pregnancy outcome and complications, percentage of women needing fertility treatment, clinical and ongoing pregnancy rates, body weight, quality of life and costs. Data will be analysed according to the intention to treat principle, and cost-effectiveness analysis will be performed to compare the costs and health effects in the intervention and control group.

Discussion

The trial will provide evidence for costs and effects of a lifestyle intervention aiming at weight reduction in overweight and obese subfertile women and will offer guidance to clinicians for the treatment of these patients.

Trial registration

Dutch Trial Register NTR1530     

Immunohistologic Analysis of Estrogen Receptor Expression in Breast Carcinoma Precursor Lesions

Abstract: The growth of invasive breast carcinoma is facilitated by abnormal expression of estrogen receptor (ER), however, the status of ER during disease histogenesis is poorly defined. The extent of ER immunostaining (expressed as percentage of positive cells) was semiquantitated in the invasive (ICA) and corresponding in situ (CIS) components of 50 formalin-fixed, paraffin-embedded breast carcinomas and then compared to staining in normal terminal duct lobular units (TDLU) or hyperplastic lesions (if present) in the same tissue sections. Morphologically normal TDLUs from most cases (61%) exhibited ER staining in 11–30% of epithelial cells; only 10% of the cases had TDLUs demonstrating immunoreactivity in more than 50% of cells. In contrast, 80% of the hyperplastic lesions showed ER staining in more than 30% of epithelial cells, with 44% demonstrating immuoreactivity in more than 50% of epithelial cell nuclei (p = 0.01, chi-square test). Although most in situ carcinomas showed even more extensive ER staining than hyperplasias (>70% of cells were positive in 50% of cases), a significant subset (28%) of CIS exhibited staining in less than 10% of cells (p = 0.002, chi-square test). Invasive carcinomas were less often extensively immunoreactive (i.e., >50% of cells positive) than CIS (32% versus 58% for CIS) and there were five cases (10%) in which the CIS component was ER positive but the invasive component was ER negative. Finally, ER-positive carcinomas were significantly more often accompained by extensive CIS and/or proliferative breast disease (p = 0.007 and 0.003, respectively). The divergent levels of ER expression observed between premalignant, preinvasive, and invasive lesions suggests that inappropriate regulation of hormone receptors may be a factor that promotes early growth or progression in breast neoplasia, and ER-positive breast carcinomas are characterized by a different, possibly lengthier, histogenesis than ER-negative malignancies with a greater frequency of background hyperplastic lesions and a larger preinvasive component.     

萘甲异喹对离体豚鼠心肌的作用

萘甲异喹(NI)呈浓度依赖性地降低离体豚鼠心房收缩力和频率。其拮抗豚鼠左房肌Iso正性肌力作用的PD2₂′值为5.4,Ver为5.8。NI10μmol/L明显降低豚鼠乳头肌收缩力;缩短快反应APD,以对APD₂₀影响最大,但不影响APA和V_max。对高K⁺去极化慢反应动作电位,NI产生浓度依赖性负性肌力作用,同时明显降低APA,V_max,缩短APD;提高细胞外液Ca²⁺浓度可使其抑制作用逆转。结果提示NI具有钙通道阻滞作用。     

Volume calculation by means of SPECT: analysis of imaging acquisition and processing factors

To assess the effect of image acquisition and processing factors on the volume calculated from single photon emission computed tomography (SPECT) images, the authors evaluated technical factors including image matrix size, size of the region of interest (ROI), activity concentration in the region, amount of background subtraction, type of reconstruction filter, section thickness, and number of projections. They found that the percentage of background subtraction was the single most important factor affecting volume calculation. The smaller the volume, the greater the amount of background subtraction needed before the ROI is drawn. As an acceptable means to circumvent the varying percentage of background subtraction for different volumes, a calibration curve was constructed relating the true volume with the calculated volume for a fixed percentage of background subtraction. The use of a 128 X 128 acquisition matrix and zooming of the reconstructed images were necessary for accurate calculation of volumes smaller than 300 mL.     

毛梗稀莶抗生育活性成分的研究

自菊科植物毛梗豨莶Siegesbeckia glabrescens Mak的全草中分得一个新的二萜甙,命名为豨莶新甙(neodarutoside),经光谱(IR,¹ HNMR,¹³ CNMR和MS)分析,确定结构为(I);同时分得的二萜有豨莶精醇(darutigenol,Ⅳ)和豨莶甙(d&rutoside,Ⅴ)。豨莶甙(Ⅴ)在20～40 mg/kg剂量时,对大鼠有明显抗早孕作用。     

Molecular phenotype of a human lymphoblastoid cell-line homoplasmic for the np 7445 deafness-associated mitochondrial mutation

We have studied mitochondrial gene expression and metabolic function in a human lymphoblastoid cell-line homoplasmic for the np 7445, deafness- associated mitochondrial DNA mutation. The mutation maps to the 3' termini of the oppositely oriented genes encoding cytochrome oxidase subunit I (COI) and tRNA-ser(UCN). In comparison with control lymphoblastoid cells, we detected a marked depletion (> 60%) of tRNA- ser(UCN). There was, however, no significant impairment of respiratory function, no alteration to the structure or abundance of COI mRNA or its precursors, and no detectable abnormality of mitochondrial protein synthesis. We also found considerable tissue-variation in the abundance of tRNA-ser(UCN). We propose that the tissue-specific phenotype associated with this mutation results from an inherent deficiency in the processing of the mutant pre-tRNA, that becomes limiting for protein synthesis only in a restricted set of cells of the auditory system in which the tRNA is, for other reasons, already at a critically low level.