Ultrasound-Assist Extrusion Methods for the Fabrication of Polymer Nanocomposites Based on Polypropylene/Multi-Wall Carbon Nanotubes

Isotactic polypropylenes (iPP) with different melt flow indexes (MFI) were used to fabricate nanocomposites (NCs) with 10 wt % loadings of multi-wall carbon nanotubes (MWCNTs) using ultrasound-assisted extrusion methods to determine their effect on the morphology, melt flow, and electrical properties of the NCs. Three different types of iPPs were used with MFIs of 2.5, 34 and 1200 g/10 min. Four different NC fabrication methods based on melt extrusion were used. In the first method melt extrusion fabrication without ultrasound assistance was used. In the second and third methods, an ultrasound probe attached to a hot chamber located at the exit of the die was used to subject the sample to fixed frequency and variable frequency, respectively. The fourth method is similar to the first method, with the difference being that the carbon nanotubes were treated in a fluidized air-bed with an ultrasound probe before being used in the fabrication of the NCs with no ultrasound assistance during extrusion. The samples were characterized by MFI, Optical microscopy (OM), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), electrical surface resistivity, and electric charge. MFI decreases in all cases with addition of MWCNTs with the largest decrease observed for samples with the highest MFI. The surface resistivity, which ranged from 10¹³ to 10⁵ Ω/sq, and electric charge, were observed to depend on the ultrasound-assisted fabrication method as well as on the melt flow index of the iPP. A relationship between agglomerate size and area ratio with electric charge was found. Several trends in the overall data were identified and are discussed in terms of MFI and the different fabrication methods.     

腹腔镜在直肠癌保肛手术中的应用与评价

腹腔镜技术存结直肠恶性肿瘤手术中的应用．是结直肠肿瘤手术发生的重大变革之一．该文主要对腹腔镜技术在直肠癌保肛手术中应用的原则、病例选择、技术关键进行论述，并对腹腔镜直肠癌保肛手术的可行性、肿瘤根治性、短期疗效、远期疗效进行了评价．认为腹腔镜直肠癌根治手术术后生命质量、远期疗效、卫生经济学评价将是今后需要探讨的重要目标．     

三明市第一医院2000年～2005年出生缺陷监测回顾性调查分析

目的了解三明市第一医院2000年～2005年六年间出生缺陷的流行病学特征。方法利用本院六年间出生缺陷资料进行统计分析。结果6年平均出生缺陷发生率178．65／万。前5位顺位依次是：颌面五官系统，骨骼肌肉系统，中枢神经系统，心血管系统，泌尿生殖系统。出生缺陷的发生与围产儿性别，产母居住地没有关系，而与孕母年龄关系很大，〈20岁及≥35岁孕妇出生缺陷发生率大大增加。结论加强全民健康教育，提高环境意识，做好婚前保健，优生保健和孕产期保健，开展产前筛查或产前诊断是减少出生缺陷发生的有力措施。     

门静脉淤血对肠源性内毒素血症及肝脏缺血再灌注损伤的影响

目的 探讨门静脉淤血对肠源性内毒素血症及肝脏缺血再灌注损伤的影响.方法 检测家兔肝脏原位冷灌注30 min后淤血的门静脉中内毒素含量,观察清除门静脉淤血对血清内毒素、丙氨酸转氨酶(ALT)、透明质酸(HA)、肝组织匀浆丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性及肝脏组织学改变的影响.结果 门静脉阻断30 min后,每去除2.5 ml淤血可使血清内毒素含量显著下降(F=52.698,P＜0.01),但去除7.5 ml后淤血中内毒素含量不再明显下降(F=1.243,P＞0.05).去除门静脉淤血能降低复流后血清内毒素、ALT、HA和肝组织匀浆中MDA,SOD含量,改善肝脏病理学变化.其中,去除门静脉淤血在5 ml与10 ml时效果最为明显,与不去除相比较差异有统计学意义(F=4.835,P＜0.05);去除门静脉淤血2.5 ml、15 ml时与不去除相比较差异无统计学意义(F=2.275,P＞0.05).结论 首批放出的5 ml门静脉淤血中内毒素含量极高,可能是引起肝脏损伤的主要原因;放掉门静脉淤血可以减轻肠源性内毒素血症和肝脏缺血再灌注损伤.     

Reversal of pulmonary hypertension and subsequent repair of atrial septal defect after treatment with continuous intravenous epoprostenol.

We report the first case in the world literature of a patient with an atrial septal defect, severe pulmonary hypertension, and equalization of pulmonary and systemic pressures, who underwent successful closure of an ASD following prolonged therapy with the intravenous vasodilator epoprostenol. Judicious use of continuous prostacyclin in apparently inoperable patients with congenital heart disease may be associated with significant reversal of pulmonary hypertension, and conversion to an operable state.     

转移相关基因nm23和P53及S100A4在晚期胃癌中的表达及与侵袭转移的相关性研究

目的探讨转移相关蛋白（nm23和P53及S100A4）在晚期胃癌转移发展过程中的意义。方法应用组织芯片和免疫组织化学方法研究nm23、P53和S100A4在74例胃癌患者的癌、癌旁、淋巴结转移、远处转移（肝脏、胰腺、卵巢等）组织中的表达。结果同癌旁组织相比，癌组织中P53和S100A4表达明显升高（P〈0．01），而nm23的表达明显降低（P〈0．05）；同癌组织相比，淋巴结中nm23的表达明显降低（P〈0．05）。远处转移组织S100A4表达明显升高（P〈0．01）。3者的阳性表达与胃癌的部分恶性生物学行为有关。癌组织中nm23^＋／P53^＋、P53^＋／S100A4^＋和nm23^＋／S100A4^＋的基因表型比例分别为48例（64．9％）、50例（67．6％）和39例（52．7％），其中P53^＋／S100A4^＋、nm23^＋／S100A4^＋和nm23^＋／P53^＋／S100A4^＋均与胃癌的高转移潜能相关。结论nm23和S100A4在肿瘤转移中发挥了重要作用；联合检测nm23、P53和S100A4的表达可用于评定胃癌的转移潜能。     

Development of a "leak-proof," knitted Dacron vascular prosthesis

We have developed a technique to render knitted Dacron prostheses totally impervious to blood leak by impregnating the cloth with collagen. These grafts were prepared by the manufacturer, sterilized, and have an indefinite shelf life. The objective of this study was to determine whether collagen impregnation has a deleterious effect on surface thrombogenicity and graft healing. The infrarenal aortas of 30 mongrel dogs were replaced with 6 cm X 6 mm Dacron grafts (15 collagen-impregnated and 15 control). The collagen-impregnated prostheses were visibly indistinguishable from the control. After blood flow was restored, no interstitial bleeding occurred in the collagen grafts, in contrast to the control grafts that initially leaked profusely. When they recovered, the dogs were divided into three groups: group I (five collagen, five control), group II (five collagen, four control), and group III (five collagen, three control). The grafts were harvested at 3, 6, and 9 months, respectively. Retroperitoneal healing response, capsular thickness and adherence, completeness of neointimal healing, surface fibrinolytic activator activity, and sections taken for light and scanning electron microscopy were studied and compared in a blinded fashion. In a separate set of experiments, experimental and control grafts were compared for in vivo surface thrombogenicity. The healing data were identical in the experimental and control prostheses in all parameters. Of particular interest was that initial capsule adherence was better and surface thrombogenicity less in the collagen-impregnated prosthesis. We conclude that collagen impregnation of a knitted Dacron prosthesis has no deleterious effect for the term of observation of this experiment.     

IS THE SEVERITY OF OSTEOSCLEROSIS OF FLUOROSIS PROPORTIONAL TO THE DOSE OF FLUORIDE INTAKE?

Histomorphometric study was made on a series of sections of undecalcified epiphyseal femoral specimens from rats with experimental fluorosis. The results revealed osteosclerosis in Group A (5 ppm) being more severe than that in Group B (25 ppm) With the increase of fluoride dose, the parameters fell down instead of increased in parallel. There is seemingly a threshold over which osteosclerosis in fluorosis becomes less severe. In contrast to Bely's conclusion the authors proposed that, fluoride toxi- city, besides decreasing the number of osteoblasts, may also activate the osteoblasts. The number of osteoblasts may be increased with relative lower dose of fluoride also. The net outcome is the in crement in bone volume. When toxic dose of fluoride is higher enough (higher than the proposed threshold), however, the number of osteoblasts and its activity are inhibited. So are the osteocytes. This interpretation may be the cytological basis for osteosclerosis in the experimental fluorosis.     

Adenylate cyclase activity as a predictor of thyroid tumor aggressiveness

Prior studies in our laboratory have shown that human thyroid neoplasms have a greater adenylate cyclase activity in response to thyroid stimulating hormone (TSH) than does the adjacent histologically normal thyroid tissue. However, there is little information relating activity of the TSH receptor-adenylate cyclase system to the type of thyroid neoplasm. Thyroid tissue from 67 patients was divided by clinical and histological criteria into 6 categories: normal (59), benign tumors (20), stage 1 carcinoma—intrathyroidal involvement only (25), stage 2 carcinomaregional lymph node involvement (6), stage 3 and 4 carcinoma—tissue invasion or distant metastasis (11), and medullary carcinoma (3). Adenylate cyclase activity in an 8,000 x g thyroid membrane preparation was determined in the basal state and when maximally stimulated with 300 mU/ml TSH. The cyclase responsiveness was the ratio of TSH stimulated adenylate cyclase activity compared to basal adenylate cyclase activity. The cyclase responsiveness by category is: normal, 2.8±0.2 (mean ± SEM); benign, 17.9±2.4; stage 1 carcinoma, 9.2±1.9; stage 2 carcinoma, 4.0±1.0; stage 3 and 4 carcinoma, 1.6±0.4; and medullary carcinoma, 1.05±0.04 (for the neoplasms,p <0.02 by ANOVA). Tumor stage was the only correlate with this trend as other prognostic risk factors (age, sex, a history of neck irradiation, or papillary versus follicular histology) showed no difference in cyclase responsiveness. These studies demonstrate a consistent inverse correlation between adenylate cyclase responsiveness and tumor stage or aggressiveness. Cyclase responsiveness appears to have clinical application for predicting which thyroid tumors will behave aggressively.

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Resumen Estudios previos en nuestro laboratorio han demostrado que los neoplasmas tiroideos humanos poseen una mayor actividad de adenilato ciclasa en respuesta a la administración de hormona estimulante de la tiroides (TSH) que el tejido tiroideo histológicamente normal adyacente. Sin embargo, existe muy poca información sobre la relation de la actividad del sistema receptor de TSH-adenilato ciclasa y el tipo del neoplasma tiroideo. Tejido tiroideo proveniente de 67 pacientes fue dividido mediante criterios chlínicos e histológicos en 6 categorias: normal (59), tumores benignos (20), extensión intratiroidea solamente en estado 1 (25), carcinoma-extensión ganglionar regional en estado 2 (6), carcinoma-invasión tisular o metástasis distantes en estados 3 y 4 (11), y carcinoma medular (3). La actividad de la adenilato ciclasa en una preparación de membrana tiroidea de 8,000 × g fue determinada en el estado basai y en estado de maxima estimulación con 300 mU/ml TSH. El grado de respuesta de la ciclasa fue la tasa de actividad de la adenilato ciclasa estimulada por TSH comparada con la actividad basai de la adenilato ciclasa. El grado de respuesta por categorías fue: normal, 2.8±0.2; tumor benigno, 17.9±2.4; carcinoma estado 1, 9.2±1.9; carcinoma estado 2, 4.0±1.0; carcinoma estados 3 y 4, 1.6±0.4; y carcinoma medular, 1.05±0.04 (para los neoplasmas,p < 0.02 por ANOVA). El estado del tumor apareció como el único factor de correlatión con esta gradación, ya que otros factures de pronóstico (edad, sexo, historia de irradiación cervical, histología papilar versus folicular) no demostraron diferencia en cuanto al grado de respuesta de la ciclasa. Estos estudios demuestran una consistente relación inversa entre el grado de respuesta de la adenilato ciclasa y el estado o agresividad tumoral. El grado de respuesta de la ciclasa parece tener aplicación clínica para predecir qué tumores tiroideos se habrán de comportar en forma agresiva.

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Résumé Les études antérieures provenant de nos laboratoires ont démontré une augmentation de l'activité enzymatique de l'adénylate-cyclase en réponse à la thyroïd stimulating hormone (TSH) dans le tissu thyroïdien humain tumoral, par rapport au tissu thyroïdien adjacent normal. Cependant il existe peu de données concernant l'activité du système récepteur TSH/adénylatecyclase par rapport au type de tumeur de la thyroïde. Les tissus thyroïdiens provenant de 67 patients différents ont été repartis en 6 groupes selon des critères cliniques et histologiques: normal (59), tumeur bénigne (20), cancer stade 1 (intrathyroïdien uniquement) (25), cancer stade 2 (envahissement ganglionnaire régional) (6), cancer stade 3 et 4 (envahissement tissulaire avoisinant ou métastases à distance (11), et cancer médullaire (3). A partir d'une préparation de membrane thyroïdienne centrifugée à 8,000 × g, l'activité de l'adénylate-cyclase a été déterminée en l'état basai et après stimulation maximale par 300 mU/ml de TSH. La réponse enzymatique a été mesurée comme étant le rapport de l'activité stimulée par la TSH/activité basale. Les résultats selon les 6 groupes étaient (moyen±ET): tissu normal, 2.8±0.2; tumeur bénigne, 17.9±2.4; cancer stade 1, 9.2±1.9; cancer stade 2, 4.0±1.0; cancers stade 3 et 4, 1.6±0.4; et cancer médullaire, 1.05±0.04 (p < 0.02 par l'analyse de variance pour les néoplasies). Le stade tumoral était la seule variable corrélée avec l'activité enzymatique. L'activité enzymatique n'était pas corrélée avec l'âge, le sexe, les antécédents d'irradiation cervicale antérieure ou l'histologie (papillaire vs. folliculaire). Ces études montrent un rapport inversement proportionnel entre l'activité d'adénylate-cyclase et le degré d'agressivité tumorale ou le stade. La réponse d l'adénylate-cyclase paraît avoir une application clinique: prévoir quelles tumeurs thyroïdiennes auront une évolution agressive.

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Presented at the International Association of Endocrine Surgeons in Sydney, Australia, September, 1987.

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Supported in part by the Medical Research Service of the Veterans Administration.     

肠道贾第虫病42例的临床分析

目的 :观察贾第虫病的临床表现及甲硝唑对贾第虫病的治疗作用。方法 :用甲硝唑治疗 42例贾第虫病患者 ,剂量为 0 .4g,日 3次 ,连服 7～ 10 d为一疗程 ,其中服 1个疗程的有 3 5例 ,服 2个疗程的有 5例 ,服 3个疗程的有 2例。结果 :经治疗后 ,全部患者的症状如腹泻及 (或 )腹痛等胃肠道症状均消失 ,粪检结果恢复正常。患者服药期间的不良反应轻 ,仅有轻微的胃肠道反应 ,如恶心、厌食等。结论 :甲硝唑治疗贾第虫病具有疗效好、耐受性好的优点