Impact and Predictors of Noncircular Left Ventricular Outflow Tract Shapes on Estimating Aortic Stenosis Severity by Means of Continuity Equations

Determining aortic stenosis (AS) severity is clinically important. Calculating aortic valve (AV) area by means of the continuity equation assumes a circular left ventricular outflow tract (LVOT). The full impact of this assumption in calculating AV area is unknown. Predictors of noncircular LVOT shape in patients with AS are undefined.In 109 adult patients with AS who underwent multiplanar transesophageal echocardiography, we calculated AV area by means of the standard continuity method and by a modified method involving planimetric LVOT area.We found 54 circular, 37 horizontal-oval, 8 vertical-oval, and 10 irregular LVOTs. Area derived by direct planimetry correlated better with the modified than the standard continuity method (r=0.89 vs r=0.85; both P=0.0001). Valve areas of patients with mild, moderate, or severe AS by planimetry were more often mischaracterized with use of the standard than modified method (29 vs 18; P <0.0001). Horizontal-oval AV area derived by planimetry (1.28 ± 0.55 cm²) was underestimated by the standard method (1.05 ± 0.47 cm²; P=0.001), but not by the modified method. Congenital AV morphology and low cardiac index were the only multivariate predictors of horizontal-oval shape. Low cardiac index was the only predictor of noncircular shape.More than half our patients with AS had noncircular LVOTs. Using the modified method reduces mischaracterizations of AS severity. Congenital AV morphology and low cardiac index predict horizontal-oval or noncircular shape. These data suggest the value of direct LVOT measurement to calculate AS severity in patients who have congenital AV or a low cardiac index.     

人血浆作为真皮支架对自体皮肤增殖的影响：组织学和免疫组织化学试验●☆

背景：组织工程是一个多学科研究的交叉学科，其目标是使人体损伤的组织和器官再生，通过这种假设，几乎所有的动物组织都可以在实验室进行培养。一般的方法是从需要移植的患者身上提取干细胞，在一定的支持条件下允许其生长、增殖、生产为可替换的组织。另一方面，寻找细胞能够互相联结并形成分层结构的合适的支持条件，如基质或支架等非常必要。目前用于烧烫伤治疗的材料有很多种，如胶原，透明质酸、纤维蛋白和聚乳酸及其共聚物。 目的：讨论以新型的生物材料自体血浆为支架对自体成纤维细胞和角质化细胞生长、扩张、增殖的影响。 设计：建立一种真皮再生的方法，将自体成纤维细胞浸于人血浆基质中，排除各种影响样本安全性和排斥反应的问题，应用同样的方法在新的真皮上获取角质化细胞。 时间及地点：实验于2008年在意大利曼多瓦C. Poma医院动物工厂完成。 材料：人角质化细胞和成纤维细胞取自1例58岁乳房切除患者的皮肤碎片。实验得到C. Poma医院独立伦理委员会批准，患者知情同意。 方法：从自体活组织皮肤样本中分离人角质化细胞和成纤维细胞，置于培养瓶中增殖，随后将自体血浆作为皮肤移植形成构造的支架，免疫和免疫组织化学特征显示与正常皮肤相似。 主要观察指标：将血浆样本用甲醛固定，埋入石蜡，苏木精-伊红染色，用显微镜进行细胞计数。所有样本均经免疫组织化学评估。 结果：在血浆基质上获得了多层规则形状的角质化细胞和成纤维细胞，基底膜的形成说明自体血浆是角质化细胞和成纤维细胞的生长、分化、扩展的良好支架，真皮和表皮细胞联结重建皮肤移植与正常皮肤无异。 结论：血浆作为角质化细胞和成纤维细胞分化、扩展的支架表现出良好的性能，同时实验还特别发现成纤维细胞浓缩血浆可以暂时替代皮肤，也是角质化细胞生长的强有力的支架。此外血浆还具有廉价，易于制备等优点。自体角质化细胞和成纤维细胞及自体血浆的应用，可以避免血种类型的免疫排斥反应。这种治疗方法给有慢性缺损并且需要连续移植的患者带来了希望。 doi:10.3969/j.issn.1673-8225.2009.47.001     

老年人视网膜中央血管在前部视神经的解剖特征

目的：观察老年人前部视神经视网膜中央血管的解剖特征。 方法：通过组织连续切片和计算机影像分析，观察60~82岁老年人的18只眼球标本中无解剖变异的视网膜中央动脉(CRA)15条，视网膜中央静脉（CRV）23条在筛板前、筛板区及筛板后的管径变化。 结果：老年人筛板前、筛板区、筛板后CRA平均面积的均值分别为（12.70,17.40,18.00）×10^-3mm^2_;平均周长的均值分别为0.56，0.56，0.57mm，平均周长之间相比无显著差异。CRV平均面积的均值分别为（7.00，5.40，7.90）×10^-3mm²；平均周长的均值分别为0.44，0.38，0.41mm；CRV平均周长筛板前与筛板区相比，筛板区与筛板后相比均有显著差异。 结论：老年人CRA眼球内外管径一致；CRV在筛板区管径最小。 （中华眼底病杂志，1997，13：213-214）
     

补肾抗衰口服液对大鼠衰老模型免疫器官影响的实验研究

研究补肾抗衰口服液对大鼠衰老模型免疫器官胸腺和脾脏的影响.结果显示,模型组大鼠胸腺和脾脏重量减轻,胸腺重/体重比值、脾重/体重比值减小,胸腺组织学观察,显示萎缩改变;药物组大鼠胸腺和脾脏重量、胸腺重/体重、脾重/体重比值接近正常对照组,胸腺组织学观察,未显示萎缩改变.本研究结果表明,补肾抗衰口服液能延缓胸腺和脾脏萎缩,保护机体的正常免疫功能,提示该药有抗衰老的作用.     

ENDOSCOPIC ULTRASOUND GUIDED TRUCUT BIOPSY

Endoscopic ultrasound (EUS) is sensitive for staging gastrointestinal malignancies and pancreatic lesions. EUS‐fine‐needle aspiration (EUS‐FNA) offers a diagnostic accuracy of about 60–90% for pancreatic tumors and > 90% for lymph nodes. There are several limitations of EUS‐FNA including the need for on‐site cytopathology review. In addition, accuracy of cytologic review is hampered by the presence of blood, benign epithelial cells, desmoplasia, and well‐differentiated tumors. Furthermore, the small biopsy sample and destruction of tissue architecture limits the diagnostic sensitivity for GISTs and lymphomas. Many of these problems can be overcome with use of EUS trucut biopsy (TCB) needles. These large caliber, cutting needles acquire larger tissue samples allowing preservation of tissue architecture and histologic examination. Our recently described experience with EUS‐TCB initially in swine and later humans demonstrated the safety for acquiring histologic tissue representative of the target organs sampled enabling accurate diagnosis. These studies suggested greater diagnostic accuracy of EUS‐TCB for submucosal mass lesions and lymphoma and potentially the need for fewer needle passes for solid pancreatic neoplasms. In this paper we will review the current TCB literature, device design and technique, help troubleshoot potential problems, and offer opinion as to the utility and role of this new device.     

Dysplastic naevus: histological criteria and their inter-observer reproducibility

Forty melanocytic lesions were examined in a pilot study, which was followed by a final series of 100 consecutive melanocytic lesions, in order to evaluate the inter-observer reproducibility of the histological criteria proposed for the dysplastic naevus. The specimens were examined in a blind fashion by four observers. Analysis by kappa statistics showed poor reproducibility of nuclear features, while reproducibility of architectural features was acceptable, improving in the final series. Consequently, we cannot apply the combined criteria of cytological and architectural features with any confidence in the diagnosis of dysplastic naevus, and, until further studies have documented that architectural criteria alone will suffice in the diagnosis of dysplastic naevus, we, as pathologists, shall avoid this term.     

Reactions in rat gluteal muscle to titanium implants

A new approach to the analysis of tissue-implant interaction is presented using rat gluteal muscle as implantation site and using monoclonal antibodies to identify and quantify cells around the implant. The method can be used for comparative studies on biocompatibility. In this methodological investigation, pure titanium (Ti) was studied, revealing an initial response of macrophages, followed by the formation of a fibrous membrane, in which, even at 50 and 70 d, la-expressing cells and suppressor T-lymphocytes were present.     

肝动脉解剖变异在中晚期肝癌介入治疗中的意义

目的 探讨放射学肝动脉解剖变异及其在中晚期肝癌介入导管治疗中的临床意义。方法 回顾性分析125例中晚期肝癌肝动脉造影表现及其介入治疗资料。结果 125例中107例(85．6％)有典型肝动脉分布。肝动脉变异18例(14．4％)，其中肝右动脉变异10例(8％)，而又以肝右动脉始于肠系膜上动脉者最多，占6．4％。副肝左动脉变异1例(0．8％)。肝左动脉和肝右动脉同时变异2例(1．6％)。肝总动脉变异3例(2．4％)。胃十二指肠动脉起自肝右动脉和腹腔动脉各1例(1．6％)。对123例成功进行了肝动脉化疗栓塞，2例肝右动脉变异因角度关系超选插管未成功。结论 认识肝动脉解剖变异有助于提高插管的成功率和中晚期肝癌的介入治疗疗效。     

Healthy lungs tolerate repetitive collapse and reopening during short periods of mechanical ventilation

The possible occurrence of lung damage if alveolar units are allowed to collapse and reopen breath by breath during mechanical ventilation with normal tidal volumes was investigated. Anaesthetised, paralysed, open chest rabbits were subjected to either intrathoracic negative (NEEP; n=6) or positive (PEEP; n=6) end-expiratory pressure during volume controlled mechanical ventilation. Both experimental settings were preceded by a 30 min control period and followed by a 30 min recovery period during which a PEEP of 0.2 kPa was maintained. Pao₂ and pulmonary compliance deteriorated significantly in the NEEP group during the experimental period and compared to ventilation with PEEP. Partial restoration of lung mechanics and blood gases was achieved during the recovery period. After an alveolar recruitment manoeuvre, this recovery was complete. Lung clearance studied by depositing an aerosol of technetium-99m-labelled diethylenetriamine pentaacetate (^99mTc-DTPA) in the alveoli, was significantly faster during ventilation with NEEP compared to the PEEP group ( P =0.0002) as well as the control period ( P = 0.0029). It did not recover completely during the recovery period but remained significantly faster. light microscopic histology was normal in both groups with no evidence of inflammation or epithelial disruption. We conclude that previously healthy rabbit lungs show only a transient disturbance of lung mechanics and blood gases with repetitive collapse and re-expansion. The integrity of the alveolar rnicrostructure is preserved. The disturbance in the alveolo-capillary permeability persists and may indicate surfactant related alveolo-capillary barrier dysfunction.     

Abnormal cardiac histology in severe intrauterine growth retardation infants

Four infants with severe intrauterine growth retardation (IUGR) weighing less than 1000 g at birth developed heart failure and died in our unit, where heart failure of IUGR infants is the main reason of death in extremely low birth-weight infants. The causes of their heart failure are one of the main themes in current neonatal medicine. The subjects of this study were four small for gestational age infants; all died due to heart failure 5 to 10 days after birth. Microscopic specimens of hearts from autopsies were evaluated with respect to the following characteristics: thickness of myocardial fibers, maturation of nuclei, presence of dysgenesis or necrosis in myocardium, and amount of glycogen in the heart. Neither dysgenesis nor infarction of the heart was found but hypoplasia in myocardial fibers and decreased glycogen levels were observed. Maturation delay in myocytes' nuclei did not appear to be severe. We conclude that these infants' hearts failed to adapt to postnatal hemodynamic changes because of inadequate myocardial function and inadequate glycogen reserves.