Outline of clinical diagnostics of the internal diseases of domestic animals.

Mode of access: Internet.

Climate diagnostics bulletin /

Mode of access: Internet.

Outlines of clinical diagnostics of the internal diseases of domestic animals

Mode of access: Internet.

Preparation of immuno-stimulating complexes (ISCOMs) by ether injection

preparation of liposomes, as a new, continuous and potentially scaleable method for the preparation of ISCOMs. Phosphatidylcholine (PC) and cholesterol (Chol) were dissolved in ether, which was injected into an aqueous solution, maintained at 55 degrees C, containing Quil A. The influences of the following variables on ISCOM formation were investigated: ratio of PC:Quil A:Chol used, pumping rate, total lipid mass and concentration of buffer salts and Quil A in the aqueous phase. All samples were characterized by negative stain transmission electron microscopy, photon correlation spectroscopy and sucrose ultracentrifugation gradient. It was demonstrated that ISCOMs could be produced by this method but the homogeneity of the preparation was influenced by the conditions used. Homogeneous ISCOM preparations were consistently produced only when the weight ratio of PC:Quil A:Chol was 5:3:2 with a total lipid mass of 20 mg, the Quil A dissolved in a 0.01 M phosphate buffer at a concentration of 6 mg in 4 ml, and the ether solution injected into the warmed buffer solution at a rate of 0.2 ml/min. Changing any of these variables resulted in more heterogeneous preparations in which ISCOMs typically co-existed with other colloidal structures such as worm-like and helical micelles, liposomes, lamellae and lipidic particles. (C) 2005 Elsevier B.V. All rights reserved.

Saponins from Quillaja saponaria Molina: Isolation, Characterization and Ability to Form Immuno Stimulatory Complexes (ISCOMs)

ISCOMs have received much attention as vaccine adjuvants due to their immunostimulatory effects. They are colloidal particles typically comprised of phospholipids, cholesterol and Quil A, a crude mixture of saponins extracted from the bark of Quillaja saponaria Molina. We have previously shown that ISCOMs can be prepared by ether injection wherein an ether solution of phospholipids and cholesterol in a mass ratio of 5:2 is injected into a solution of Quil A at a mass ratio of 7 lipids: 3 Quil A. The aim of this study was firstly to isolate and characterise discrete fractions of Quil A and secondly to investigate which of these fractions were able to form ISCOMs by the method of ether injection. Six fractions of Quil A were isolated by semi-preparative reverse phase high performance liquid chromatography (RP-HPLC) and characterised by analytical HPLC, liquid chromatography tandem mass spectrometry (LC-MS) and the qualitative Liebermann- Burchard and Molisch tests for triterpenoids and carbohydrates respectively. ISCOMs were subsequently prepared from the isolated fractions by the method of ether injection and the resulting preparations characterized by photon correlation spectroscopy (PCS) and negative stain transmission electron microscopy (TEM). The molecular weights of the major compounds in the fractions ranged from ∼1200 to ∼2300 Da; all fractions tested positive for triterpenoids and saccharides and four of the fractions were identified as QS-7, QS-17, QS-18 and QS-21 by analysis (LC-MS and analytical HPLC). Injection of ether solutions of lipids into aqueous solutions of QS-17, QS-18 or QS-21 all resulted in homogeneous ISCOM dispersions. The combination of lipids and QS-7 by ether injection produced lamellae and liposomes as the prominent structures and a minor amount of ISCOMs. The remaining two hydrophilic, low molecular weight fractions of Quil A did not produce ISCOMs, instead liposomes and helical structures predominated in the samples.

Computer-aided biotechnology:from immuno-informatics to reverse vaccinology

Genome sequences from many organisms, including humans, have been completed, and high-throughput analyses have produced burgeoning volumes of 'omics' data. Bioinformatics is crucial for the management and analysis of such data and is increasingly used to accelerate progress in a wide variety of large-scale and object-specific functional analyses. Refined algorithms enable biotechnologists to follow 'computer-aided strategies' based on experiments driven by high-confidence predictions. In order to address compound problems, current efforts in immuno-informatics and reverse vaccinology are aimed at developing and tuning integrative approaches and user-friendly, automated bioinformatics environments. This will herald a move to 'computer-aided biotechnology': smart projects in which time-consuming and expensive large-scale experimental approaches are progressively replaced by prediction-driven investigations.

Immuno-potentiating activity of surfactant vesicles in DNA and subunit vaccination

Enhanced immune responses for DNA and subunit vaccines potentiated by surfactant vesicle based delivery systems outlined in the present study, provides proof of principle for the beneficial aspects of vesicle mediated vaccination. The dehydration-rehydration technique was used to entrap plasmid DNA or subunit antigens into lipid-based (liposomes) or non-ionic surfactant-based (niosomes) dehydration-rehydration vesicles (DRV). Using this procedure, it was shown that both these types of antigens can be effectively entrapped in DRV liposomes and DRV niosomes. The vesicle size of DRV niosomes was shown to be twice the diameter (~2µm) of that of their liposome counterparts. Incorporation of cryoprotectants such as sucrose in the DRV procedure resulted in reduced vesicle sizes while retaining high DNA incorporation efficiency (~95%). Transfection studies in COS 7 cells demonstrated that the choice of cationic lipid, the helper lipid, and the method of preparation, all influenced transfection efficiency indicating a strong interdependency of these factors. This phenomenon has been further reinforced when 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE): cholesteryl 3b- [N-(N’ ,N’ -dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol)/DNA complexes were supplemented with non-ionic surfactants. Morphological analysis of these complexes using transmission electron microscopy and environmental scanning electron microscopy (ESEM) revealed the presence of heterogeneous structures which may be essential for an efficient transfection in addition to the fusogenic properties of DOPE. In vivo evaluation of these DNA incorporated vesicle systems in BALB/c mice showed weak antibody and cell-mediated immune (CMI) responses. Subsequent mock challenge with hepatitis B antigen demonstrated that, 1-monopalmitoyl glycerol (MP) based DRV, is a more promising DNA vaccine adjuvant. Studying these DRV systems as adjuvants for the Hepatitis B subunit antigen (HBsAg) revealed a balanced antibody/CMI response profile on the basis of the HBsAg specific antibody and cytokine responses which were higher than unadjuvated antigen. The effect of addition of MP, cholesterol and trehalose 6,6’-dibehenate (TDB) on the stability and immuno-efficacy of dimethyldioctadecylammonium bromide (DDA) vesicles was investigated. Differential scanning calorimetry showed a reduction in transition temperature of DDA vesicles by ~12°C when incorporated with surfactants. ESEM of MP based DRV system indicated an increased vesicle stability upon incorporation of antigen. Adjuvant activity of these systems tested in C57BL/6j mice against three subunit antigens i.e., mycobacterial fusion protein- Ag85B-ESAT-6, and two malarial antigens - merozoite surface protein-1, (MSP1), and glutamate rich protein, (GLURP) revealed that while MP and DDA based systems induced comparable antibody responses, DDA based systems induced powerful CMI responses.

Case-based Reasoning Method for Real-time Expert Diagnostics Systems

The method of case-based reasoning for a solution of problems of real-time diagnostics and forecasting in intelligent decision support systems (IDSS) is considered. Special attention is drawn to case library structure for real-time IDSS (RT IDSS) and algorithm of k-nearest neighbors type. This work was supported by RFBR.

Groud of Model for the Generalized Criterion Forming at Differential Diagnostics of Dermatological Diseases

The basic methods of decisions making in multi-criterion conditions are considered, from which the method of the weighed total for calculation of diagnostic indexes significance in differential diagnostics of dermatological diseases is chosen.

An Idea of a Computer Knowledge Bank on Medical Diagnostics

The paper is a description of information and software content of a computer knowledge bank on medical diagnostics. The classes of its users and the tasks which they can solve are described. The information content of the bank contains three ontologies: an ontology of observations in the field of medical diagnostics, an ontology of knowledge base (diseases) in medical diagnostics and an ontology of case records, and also it contains three classes of information resources for every division of medicine – observation bases, knowledge bases, and data bases (with data about patients), that correspond to these ontologies. Software content consists of editors for information of different kinds (ontologies, bases of observations, knowledge and data), and also of a program which performs medical diagnostics.

Towards novel compact laser sources for non-invasive diagnostics and treatment

An important field of application of lasers is biomedical optics. Here, they offer great utility for diagnosis, therapy and surgery. For the development of novel methods of laser-based biomedical diagnostics careful study of light propagation in biological tissues is necessary to enhance our understanding of the optical measurements undertaken, increase research and development capacity and the diagnostic reliability of optical technologies. Ultimately, fulfilling these requirements will increase uptake in clinical applications of laser based diagnostics and therapeutics. To address these challenges informative biomarkers relevant to the biological and physiological function or disease state of the organism must be selected. These indicators are the results of the analysis of tissues and cells, such as blood. For non-invasive diagnostics peripheral blood, cells and tissue can potentially provide comprehensive information on the condition of the human organism. A detailed study of the light scattering and absorption characteristics can quickly detect physiological and morphological changes in the cells due to thermal, chemical, antibiotic treatments, etc [1-5]. The selection of a laser source to study the structure of biological particles also benefits from the fact that gross pathological changes are not induced and diagnostics make effective use of the monochromatic directional coherence properties of laser radiation.