Epitope selection and their placement for increased virus neutralization in a novel vaccination strategy for porcine epidemic diarrhea virus utilizing the Hepatitis B virus core antigen

Porcine epidemic diarrhea virus (PEDV) is a member of the Alphacoronaviridae genus within the Coronaviridae family. It is the causative agent of porcine epidemic diarrhea, a disease that can have mortality rates as high as 100% in suckling piglets. PEDV causes severe economic loss, and has been in existence for decades. A panzootic starting in 2010 renewed interest in the development of a universal vaccine toward PEDV. This report details several design changes made to a Hepatitis B virus core antigen (HBcAg)-based recombinant vaccine strategy, and their effect in vivo. Initially, several multi-antigen vaccine candidates were able to elicit antibodies specific to three out of four B-cell epitopes inserted into the chimeric proteins. However, a lack of virus neutralization led to a redesign of the vaccines. The focus of the newly redesigned vaccines was to elicit a strong immune response to the YSNIGVCK amino acid motif from PEDV. Genetically modified new vaccine candidates were able to elicit a strong antibody (Ab) response to the YSNIGVCK epitope, which correlated with an increased ability to neutralize the CO strain of PEDV. Additionally, the location of the inserted PEDV epitopes within the vector protein was shown to affect the immune recognition toward the native HBcAg during vaccination.     

A mobile laminar airflow unit to reduce air bacterial contamination at surgical area in a conventionally ventilated operating theatre

The aim of this study was to evaluate the efficacy of a mobile laminar airflow (LAF) unit in reducing bacterial contamination at the surgical area in an operating theatre supplied with turbulent air ventilation. Bacterial sedimentation was evaluated during 76 clean urological laparotomies; in 34 of these, a mobile LAF unit was added. During each operation, settle plates were placed at four points in the operating theatre (one at the patient area and three at the perimeter), a nitrocellulose membrane was placed on the instrument table and an additional membrane near the wound. During four operations, particle counting was performed to detect particles > or =0.5 microm. Mean bacterial sedimentation on the nitrocellulose membrane on the instrument table was 2730 cfu/m(2)/h under standard ventilation conditions, whereas it decreased significantly to a mean of 305 cfu/m(2)/h when the LAF unit was used, i.e. within the suggested limit for ultraclean operating theatres (P=0.0001). The membrane near the wound showed a bacterial sedimentation of 4031 cfu/m(2)/h without the LAF unit and 1608 cfu/m(2)/h with the unit (P=0.0001). Particle counts also showed a reduction when the LAF unit was used. No significant difference was found at the four points in the operating theatre between samplings performed with, and without, the LAF unit. Use of a mobile LAF unit with turbulent air ventilation can reduce bacterial contamination at the surgical area in high-risk operations (e.g. prosthesis implant).     

复方芩部丹颗粒治疗阴虚火旺型耐多药肺结核

目的观察复方芩部丹颗粒辅助化疗药物治疗阴虚火旺型耐多药肺结核(MDR-PTB)强化期的临床疗效。方法采用多中心、随机、平行对照临床研究,纳入符合标准MDR-PTB患者72例,治疗组、对照组各36例。对照组采用基础化疗方案(6 Amk,Pa,Lfx+15 Pa,Lfx)+X(X药物由各中心专家根据患者个体病况选择,原则不超过3种)治疗,治疗组在给予基础化疗方案的同时服用复方芩部丹颗粒。观察比较2组治疗前、强化期治疗结束时(治疗第6个月)痰结核菌培养、痰抗酸杆菌涂片、胸片、中医证候积分。结果强化期治疗结束时,治疗组、对照组痰菌转阴率无统计学意义(P0.05);痰涂片阳性分级计数2组分别与治疗前比较均有显著性下降(P0.05),2组间比较有统计学意义(P0.05);在胸片病灶吸收、空洞闭合缩小、中医证候积分方面,治疗组优于对照组,2组间比较有统计学意义(P0.05)。结论复方芩部丹颗粒能降低阴虚火旺型MDR-PTB患者痰液结核菌含量,降低传染性,能促进阴虚火旺型MDR-PTB患者肺部病灶吸收、空洞缩小及闭合,减轻患者症状。     

糖类抗原CA19-9光激化学发光免疫分析方法的建立

目的:建立一种检测人血清糖类抗原CA19-9(CA19-9)浓度的光激化学发光免疫分析方法。方法:采用2株针对不同抗原表位的抗CA19-9抗体,其中一株抗体用来包被发光微粒,另一株抗体标记生物素,以双抗体夹心法检测血清中CA19-9浓度,并与Roche公司试剂(电化学发光法)进行比较。结果:发光微粒浓度为25 mg/ml、生物素标记抗体浓度为16.17 mg/ml时,监测范围为0 U/ml～500 U/ml,灵敏度为0.27 U/ml,平均回收率为101.26%,批内变异系数(CV)为1.67%～4.35%,批间CV为1.12%～3.25%,与CEA、CA12-5、CA15-3的交叉反应率低,稳定性好,与电化学发光免疫分析法的符合率高(符合率=98.8%,γ=0.991)。结论:光激化学发光免疫分析方法测定CA19-9具有高灵敏度、精密度和准确性,与电化学发光免疫分析法的符合率高,适用于临床测定。     

Analysis of flow within a left ventricle model fully assisted with continuous flow through the aortic valve

Blood compatibility of a ventricular assist device (VAD) depends on the dynamics of blood flow. The focus in most previous studies was on blood flow in the VAD. However, the tip shape and position of the VAD inflow cannula influence the dynamics of intraventricular blood flow and thus thrombus formation in the ventricle. In this study, blood flow in the left ventricle (LV) under support with a catheter-type continuous flow blood pump was investigated. The flow field was analyzed both numerically and experimentally to investigate the effects of catheter tip shape and its insertion depth on intraventricular flow patterns. A computational model of the LV cavity with a simplified shape was constructed using computer-aided design software. Models of catheters with three different tip shapes were constructed and each was integrated to the LV model. In addition, three variations of insertion depth were prepared for all models. The fully supported intraventricular flow field was calculated by computational fluid dynamics (CFD). A transparent LV model made of silicone was also fabricated to analyze the intraventricular flow field by the particle image velocimetry technique. A mock circulation loop was constructed and water containing tracer particles was circulated in the loop. The motion of particles in the LV model was recorded with a digital high-speed video camera and analyzed to reveal the flow field. The results of numerical and experimental analyses indicated the formation of two large vortices in the bisector plane of the mitral and aortic valve planes. The shape and positioning of the catheter tip affected the flow distribution in the LV, and some of these combinations elongated the upper vortex toward the ventricular apex. Assessment based on average wall shear stress on the LV wall indicated that the flow distribution improved the washout effect. The flow patterns obtained from flow visualization coincided with those calculated by CFD analysis. Through these comparisons, the numerical analysis was validated. In conclusion, results of these numerical and experimental analyses of flow field in the LV cavity provide useful information when designing catheter-type VADs.     

Chitosan nanoparticles as non-viral gene delivery systems: Determination of loading efficiency

Chitosan has been studied for use in particle delivery systems for therapeutic purposes, since one of its most important applications is as a non-viral vector in gene therapy. Due to its positive charge, it is capable of forming DNA complexes (polyplexes) obtained through several methods and with the property of protecting nucleic acids. Two methods for obtaining the nanoparticles of chitosan-nucleic acids are reported in this study: simple complexation (of depolymerized chitosan or of different chitosan salts with plasmid) and ionic gelation (by adsorption of plasmid in the nanoparticles or by encapsulation of plasmid into nanoparticles). The determination of the loading efficiency of chitosan nanoparticles with the plasmid is carried out by electrophoretic mobility of the samples on agarose gel. Furthermore, the nanoparticles have been characterized according to their morphology, size and surface charge using AFM, TEM, laser diffraction and dynamic light scattering techniques. The polyplexes obtained have been found to be spherical and nanometric in size (between 100–230 nm) with a zeta potential between 37 and 48 mV. Positive results have been obtained by agarose gel electrophoresis for all studied cases: a concentration of between 20 and 30 μg/mL of chitosan salts is required while for the remaining chitosan samples studied, 100% loading efficiency does not occur until a concentration equal to 100 μg/mL (regardless of previous depolymerisation and the method performed). Chitosan–plasmid nanocapsules have been obtained at the polymer concentrations worked with (between 0.025 and 0.2%).     

Osteoclasts and Biomaterials

Abstract There is a growing market of biomaterials for orthopedic applications. As soon as these materials are surgically introduced into the constantly remodeling bone of the patient, they start to interact with the local cells: osteoblasts and osteoclasts. At the first glance, the bone building osteoblasts seem to be the more important cells for osseointegration of implants. However, it is mainly the bone resorbing action of osteclasts that determines the longevity of the implant. In this paper, we give a short overview over the current understanding of osteoclast biology; we review the interaction between biomaterials, biomaterial particles and osteoclasts, and the effects of treatment with antiosteoclastic agents like bisphosphonates on biomaterial implant healing.     

Pion radiotherapy at LAMPF

Clinical investigations of pi meson radiotherapy were conducted by the Cancer Research and Treatment Center of the University of New Mexico and the Los Alamos National Laboratory from 1974 until 1982. Two hundred and thirty patients have been treated for a variety of locally advanced primary and metastatic neoplasms. One hundred and ninety-six patients have been followed for a minimum of 18 months. Crude survival data range from 11% for unresectable pancreatic carcinoma to 82% for Stages C and D1 adenocarcinoma of the prostate. Acute tolerance of normal tissues is approximately 4500 pion rad in 36 fractions over 7 weeks. Severe chronic reactions have appeared with increasing frequency after doses in excess of 4000 pion rad.     

沉降法测定大气真菌粒子含量的探讨

本工作用 ANDERSEN 生物粒子采样器法和平皿沉降法在北京西单对大气真菌粒子的含量进行了一年的对比观测实验。结果表明,在同一次大气真菌粒子沉降量的采样中,放置的采样皿数对测定结果没有明显影响。大气真菌粒子沉降量与大气真菌粒子含量呈非常显著的正相关关系。由本实验得出的关系式能较准确、简便的计算大气真菌粒子的含量。