动态比浊法鲎试验定量分析催化剂的细菌内毒素

目的通过定量检测催化剂的细菌内毒素含量,为控制药品质量及筛选最佳生产工艺提供参考。方法应用动态比浊法及凝胶法鲎试验对催化剂的细菌内毒素进行定量和半定量检测。结果动态比浊法鲎试验定量检测了4批催化剂,其原液(原瓶加5.0mL水)细菌内毒素含量依次为20EumL-1-50EumL-1不等,样品在256倍稀释时其添加内毒素(2.0EumL-1)的回收率在75%-125%之间,此时对鲎试验反应无干扰作用,与凝胶法的检查结果一致。结论动态比浊法鲎试验可用来定量检测催化剂的细菌内毒素含量。     

Decreased bacterial clearance from the lungs of mice following primary respiratory syncytial virus infection

Virus respiratory infections often precede bacterial pneumonia in healthy individuals. In order to determine the potential role of respiratory syncytial virus (RSV) in bacterial secondary infections, a mouse sequential pulmonary infection model was developed. Mice were exposed to RSV then challenged with Streptococcus pneumoniae (StPn). Exposure of BALB/c mice to 10(6)-10(7) plaque forming units (pfu) of virus of RSV significantly decreased StPn clearance 1-7 days following RSV exposure. This finding was not restricted to StPn alone: exposure to RSV followed by Staphylococcus aureus (SA) or Pseudomonas aeruginosa(PA) resulted in similar decreases in bacterial clearance. Both bronchoalveolar lavage (BAL) cell counts and pulmonary histopathology demonstrated that RSV-StPn exposed mice had increased lung cellular inflammation compared to mice receiving StPn or RSV alone. The effect of RSV infection on bacterial clearance was dependent on the mouse genetic background: C57BL/6J mice (relatively resistant to RSV infection) demonstrated a modest change in StPn clearance following RSV exposure, whereas FVBN/J mice (similar to the BALB/cJ mice in RSV susceptibility) demonstrated a similar degree of RSV-associated decrease in StPn clearance 7 days following RSV exposure. Neutrophils from the RSV-StPn sequentially exposed BALB/cJ mice were functionally altered-produced greater levels of peroxide production but less myeloperoxidase (MPO) compared to mice receiving StPn alone. These data demonstrate that RSV infection decreases bacterial clearance, potentially predisposing to secondary bacterial pneumonia despite increased lung cellular inflammation, and suggest that functional changes occur in the recruited neutrophils that may contribute to the decreased bacterial clearance.     

人类与医学遗传学群体与家系资料分析计算机系统：连锁分析

本文简介我们用C语言编制的人类与医学遗传学群体与家系资料分析计算机系统中的连锁分析的功能,包括常染色体位点连锁分析、X染色体位点连锁分析、常染色体连锁异质性分析.对人类与医学遗传学及遗传流行病学研究都很有实用价值.     

Tolerance to lipopolysaccharide promotes an enhanced neutrophil extracellular traps formation leading to a more efficient bacterial clearance in mice

Tolerance to lipopolysaccharide (LPS) constitutes a stress adaptation, in which a primary contact with LPS results in a minimal response when a second exposure with the same stimulus occurs. However, active important defence mechanisms are mounted during the tolerant state. Our aim was to assess the contribution of polymorphonuclear neutrophils (PMN) in the clearance of bacterial infection in a mouse model of tolerance to LPS. After tolerance was developed, we investigated in vivo different mechanisms of bacterial clearance. The elimination of a locally induced polymicrobial challenge was more efficient in tolerant mice both in the presence or absence of local macrophages. This was related to a higher number of PMN migrating to the infectious site as a result of an increased number of PMN from the marginal pool with higher chemotactic capacity, not because of differences in their phagocytic activity or reactive species production. In vivo, neutrophils extracellular trap (NET) destruction by nuclease treatment abolished the observed increased clearance in tolerant but not in control mice. In line with this finding, in vitro NETs formation was higher in PMN from tolerant animals. These results indicate that the higher chemotactic response from an increased PMN marginal pool and the NETs enhanced forming capacity are the main mechanisms mediating bacterial clearance in tolerant mice. To sum up, far from being a lack of response, tolerance to LPS causes PMN priming effects which favour distant and local anti-infectious responses.     

Glycation increases the vascular clearance rate of IgG in mice.

As elevated levels of glycated IgG have been detected in the plasma of diabetics we have investigated whether glycation of IgG affects its vascular clearance rate, using a mouse model system. Polyclonal mouse IgG was aseptically incubated for 14-19 days with 0.5 M glucose in 0.1 M phosphate buffer (pH 7.4) at 37 degrees C. As control, IgG was incubated under identical conditions but with no added glucose. After incubation, both forms were labelled with 125I and injected intravenously into BALB/c mice. The rate of vascular clearance of the glycated IgG was found to be significantly higher than the control IgG in the periods 5-24 h (P < 0.001, n = 6) and 24-48 h (P < 0.01, n = 6) after injection. After 2-3 days the mice were killed and the major organs were harvested. With glycated IgG there was a significant increase in the 125I accumulated in the kidney (P < 0.02). In later experiments, dual labelling with 131I and 125I allowed mixtures of glycated and unglycated IgG to be injected into the same mouse so that the vascular clearance of both forms of IgG could be followed simultaneously. These experiments confirmed that glycation of the IgG significantly increases its vascular clearance rate.     

Economic analysis of two structured treatment and teaching programs on asthma

The aims of the present study were as follows:

• 1). to evaluate the medical outcomes of two treatment and educational asthma programs
• 2). to determine by cost-analysis both cost and economic outcome of the programs
• 3). to perform a cost-benefit analysis (determining the net cost-benefit) and a cost-effectiveness analysis (determining the cost per unit of effect and the incremental cost-effectiveness ratio) from the perspective of health program policy makers (HPP; indirect costs, i.e., loss of productivity, excluded) and of society as a whole (Saw; all costs included).

Patients were randomly assigned to a complete (CP; n = 32) or reduced (RP; n = 33) program: the RP group received a reduced education (self-reading of an educational booklet on asthma), while the CP group attended an “asthma school”, consisting of six lessons based on the same booklet and including educational videotapes. Both programs included peak-flow monitoring and treatment according to international guidelines, and follow-up. The outcome variables (asthma attacks, urgent medical examinations, admission days, working days lost) did not differ significantly between CP and RP. Morbidity savings were $1894.70 (CP) and $1697.80 (RP) according to Saw, and $1349.50 and $1301.80, respectively, according to HPP. The net cost-benefit was $1181.50 for CP and $1028.00 for RP, and the cost-benefit ratio per dollar spent was 1:2.6 for CP and 1:2.5 for RP, according to Saw. One day of admission prevented had a cost of $110.20 (CP) and $94.10 (RP). CP gave slightly better results and was slightly more cost-effective than RP in improving patients' welfare. It cannot be excluded that the retrospective analysis used to determine baseline costs might have inflated differences for both groups. Sensitivity analysis was slightly in favor of RP when the outcome variables were tested at their upper and lower 95% CI.     

Antibody-mediated bacterial clearance from the lower respiratory tract of mice requires complement component C3

To assess the contribution of complement to respiratory immunity in the context of a natural bacterial infection, we used mice genetically deficient in complement components and the murine pathogen Bordetella bronchiseptica. Complement component C3 was not required for the control of bacterial infection or for the generation of infection-induced protective immunity. However, C3-deficient (C3(-/-)) mice were severely defective, compared to wild type, in vaccine-induced protective immunity. Adoptively transferred immune serum from convalescent wild-type or C3(-/-) animals rapidly cleared B. bronchiseptica from the lungs of wild-type mice but did not affect its growth in C3(-/-) mice, indicating that the defect is not in the generation of protective immunity, but in its function. Immune serum was effective in C5-deficient mice but had little effect in the lungs of mice lacking either Fcgamma receptors (FcgammaR) or CR3, suggesting bacterial clearance is not via direct complement-mediated lysis. Together, these data indicate that complement is required for antibody-mediated clearance of Bordetella and suggest the mechanism involves C3 opsonization of bacteria for phagocytosis that is both CR3- and FcgammaR-dependent.     

Boosting the IL-22 response using flagellin prevents bacterial infection in cigarette smoke-exposed mice

The progression of chronic obstructive pulmonary disease (COPD), a lung inflammatory disease being the fourth cause of death worldwide, is marked by acute exacerbations. These episodes are mainly caused by bacterial infections, frequently due to Streptococcus pneumoniae. This susceptibility to infection involves a defect in interleukin (IL)-22, which plays a pivotal role in mucosal defense mechanism. Administration of flagellin, a Toll-like receptor 5 (TLR-5) agonist, can protect mice and primates against respiratory infections in a non-pathological background. We hypothesized that TLR-5-mediated stimulation of innate immunity might improve the development of bacteria-induced exacerbations in a COPD context. Mice chronically exposed to cigarette smoke (CS), mimicking COPD symptoms, are infected with S. pneumoniae, and treated in a preventive and a delayed manner with flagellin. Both treatments induced a lower bacterial load in the lungs and blood, and strongly reduced the inflammation and lung lesions associated with the infection. This protection implicated an enhanced production of IL-22 and involved the recirculation of soluble factors secreted by spleen cells. This is also associated with higher levels of the S100A8 anti-microbial peptide in the lung. Furthermore, human mononuclear cells from non-smokers were able to respond to recombinant flagellin by increasing IL-22 production while active smoker cells do not, a defect associated with an altered IL-23 production. This study shows that stimulation of innate immunity by a TLR-5 ligand reduces CS-induced susceptibility to bacterial infection in mice, and should be considered in therapeutic strategies against COPD exacerbations.     

Measurement of hepatic blood flow in the rat using fractional clearance of indocyanine green and colloidal radiogold

Two new methods are described to measure hepatic blood flow in the anaesthetized rat. These methods are based on the fractional clearance and extraction of indocyanine green, which is removed by hepatocytes, and of colloidal radiogold, which is removed by Kupffer cells. Hepatic blood flow was found to be 2.11±0.35 ml·min^–1·g liver^–1 (mean ±SD) and 2.01±0.31 ml·min^–1·g liver^–1, respectively, with these two substances (P>0.80).     

Finite and infinitesimal representations of the vasculature: ocular drug clearance by vascular and hydraulic effects

New methods are presented for simulating steady-state drug concentration in vitreous, choroid, and sclera from an intravitreal device. Clearance by choroidal flow and intraocular pressure (IOP) -induced Darcy hydraulic flow are included. Two methods are proposed for modeling the vasculature using simple one-dimensional models for simulating drug concentration profiles from intravitreal devices. The finite choroid method adds a concentration-dependent sink term to the convective diffusion equation, allowing for a continuous but rapid decrease in concentration throughout the choroid region. The infinitesimal choroid method uses a combination of a simple flux boundary condition and a redefinition of the dependent variable to account for the impact of the vascular drain by a discontinuous drop in concentration across the exterior vitreous boundary. This eliminates the need for a choroidal region, reducing finite element memory requirements, enabling the choroid to be made arbitrarily thin. The impact of permeating fluid induced by IOP on convection was examined, using hydraulic coefficients for ocular tissue recently made available [Xu, J. [et_al.], Pharm. Res. 17:664–669 (2000)], allowing for drug efflux through the outer sclera. Transport becomes diffusion limited at high vascular clearance. Hydraulic flow restricts the range in concentration predicted in the vitreous compared to zero flow. Hydraulic influences for small, rapidly cleared drugs can be neglected. © 2002 Biomedical Engineering Society. PAC2002: 8719Uv, 4266Ct, 8780-y     

Microcomputer-based period and amplitude analysis of the electroencephalogram

A multichannel microcomputer-based e.e.g. processing system is described. Using a unique method of digitisation, analogue-to-digital preprocessors perform period measurement and either peak-to-peak amplitude or absolute integral measurement on a wave-by-wave basis in real time. A scan circuit controls the high-speed transfer of preprocessor data over a shared data bus to a single-board microcomputer. The microcomputer tests for indications of artefact, sorts and accumulates the data by channel and wave category, and outputs the formated data on command or at regular intervals to external devices for storage, display, or further processing. The suitability of this type of processing system for the analysis of periodic and aperiodic components of the e.e.g. is discussed.     

利用降钙素原判断细菌感染的临床符合性分析

目的通过实验室数据和临床综合诊断分析血清降钙素原（PCT）在判断细菌感染中的临床符合性。方法对诊断感染的常规指标C反应蛋白（CRP）、白细胞计数（WBC）、中性粒细胞比例（N％）和细菌培养与PCT进行判断感染的临床符合性分析,再对PCT与临床综合诊断结论进行统计学分析来判断感染和非感染,以及不同部位感染的差异。结果当PCT大于0．5ng／ml时与常规指标的符合性大于92％,而且随着PCT的增大符合性进一步增加;PCT与常规指标之间除CRP外均差异有统计学意义（P〈0．01）;PCT的ROC曲线下面积大于全部常规指标;细菌感染与非感染组间PCT差异有统计学意义（P〈0．01）,但对肿瘤合并感染情况较难判断;PCT全身感染与局部感染之间除伤口感染外均差异有统计学意义（P〈0．01）,但在不同部位间差异无统计学意义。结论PCT与临床广泛应用判断感染的常规指标具有较好的吻合性,PCT在判断细菌感染方面选各医院适用的CUTOFF值能起到很好的作用,可以替代常规指标。     

Pathways of cellular efflux and particulate clearance after carbon instillation to the lung

The pulmonary response to the deposition of carbon particles was investigated to determine the routes of cellular efflux and the mechanisms of particulate clearance. At intervals to 6 months after the intratracheal instillation of 4 mg carbon, the lungs of mice were fixed in situ by perfusion without lavage. Within a few hours, migration of granulocytes into the bronchioles was observed; large numbers of PMNs were not seen in alveoli until 24 h. Associated with the PMN efflux there was transient oedema with no evidence of pulmonary cell necrosis. The number of free macrophages increased in response to the carbon and mononuclear cell migration into alveoli and bronchioles was also observed. The bronchiolar component of the cellular efflux indicates that PMNs and macrophages recovered from the lung by lavage are not entirely of alveolar origin. Whereas most particles, either free or in phagocytic cells, were cleared by the bronchial tree, some transepithelial passage of free particles to the interstitium was observed. Some carbon was found in hilar lymph nodes but overall lymphatic clearance was low.     

A software package for the calculation and statistical analysis of 51Cr-release assays

A software package has been developed to calculate, store, and statistically analyze the results of 51Cr-release assays. It is written in Applesoft BASIC, is 'user friendly', and contains error trapping routines to catch most common mistakes. The greeting program contains a master menu from which one of the following programs may be called up: (1) 51Cr-release calculation, (2) statistical analysis, or (3) file manager. These programs give the user the capability to rapidly reduce cpm data to % specific release and statistically analyze the results using randomized design analysis of variance (ANOVA) and Turkey's honestly significant difference (HSD) test.     

Preparation of covalent IgG complexes of defined size and their clearance from the circulation of mice

Covalent complexes of various sizes were made by coupling the photosensitive hapten, NAP (4-azido-2-nitrophenyl), to rabbit IgG and reacting the conjugates with rabbit anti-NAP antibodies. The resultant oligomers were stable, being eluted as the same discrete peaks after chromatography on gels both before and after injection into mice. Tests of their biological properties showed they fixed guinea pig complement in vitro in a size-dependent manner. Normal mice and mice with chronic endogenous circulating complexes cleared the oligomers according to size in a manner best described by a two-component exponential curve. There was no difference in the clearance rates between the two groups of mice. The advantages of these model complexes for examining the effect of circulating complexes on the mononuclear phagocyte system are discussed.     

Theoretical analysis of the transient thermal clearance method for regional blood flow measurement

In the noninvasive transient thermal clearance method a metal plate at room temperature is attached to the investigated skin. The plate is thermally insulated from the environment, and so the tissue temperature, after an initial decrease, is increased at a rate which depends both on heat convection by blood and on tissue thermal conductivity. The corresponding bioheat conductivity equation is solved and the dependence of plate temperature on time and on blood flow discussed. It is shown that, for an appropriate choice of metal and plate thickness, regional blood flow can be derived from temperature/time curves.     

Intravascular clearance of disseminating Cryptococcus neoformans in the brain can be improved by enhancing neutrophil recruitment in mice

Extrapulmonary dissemination of Cryptococcus neoformans (C. neoformans) is one of the most critical steps in the development of meningoencephalitis. Here, we report that clearance of the disseminating C. neoformans occurs within the brain microvasculature. Interestingly, the efficiency of the intravascular clearance in the brain is reduced compared to that in the lung. Intravascular clearance is mainly mediated by neutrophils, and complement C5a receptor signaling is crucial for mediating neutrophil recruitment in the vasculature. C. neoformans stimulated actin polymerization of neutrophils is critically involved in their recruitment to the lung, which is associated with the unique vascular structure detected in the lung. The relatively lower efficiency of fungal clearance in the brain vasculature correlates with less efficient recruitment of neutrophils. Accordingly, intravascular clearance of C. neoformans in the brain could be remarkably improved by increasing the recruitment of neutrophils. We conclude that neutrophils have the ability to eliminate C. neoformans arrested in the vasculature. However, insufficient recruitment of neutrophils limited the optimal clearance of this microorganism in the brain. These results imply that a therapeutic strategy aimed at enhancing the accumulation of neutrophils could help prevent cryptococcal meningoencephalitis.