Rapid immunochemical identification of enterococci with use of a centrifugal analyzer after a brief antigen-extraction step.

1981 ◽  
Vol 27 (2) ◽  
pp. 293-296
Author(s):  
S S Levinson
Keyword(s):  
Optimal Conditions ◽  
Antigen Concentration ◽  
Precipitin Reaction ◽  
Extraction Step ◽  
Streptomyces Albus ◽  
Specific Antisera ◽  
Immunochemical Identification ◽  
Pure Cultures ◽  
Biochemical Media ◽  
Absorbance Changes

Abstract The precipitin reaction between antigens from enterococci and group-specific antisera was monitored turbidimetrically with a centrifugal analyzer. Linear standard curves (absorbance vs antigen concentration) were developed for studying optimal conditions for enzymic extraction of the antigen by use of an enzyme-containing filtrate from Streptomyces albus. This extraction was optimized by adding to the filtrate 1 mg of lysozyme per milliliter and incubating the bacteria for 40 min at 52 degrees C. The assay was adjusted so that detection of enterococci was indicated by positive absorbance changes near 0.1 A. When the concentration of bacteria from which the antigen was extracted was within a standardized range, non-enterococci produced no positive absorbance changes. Reproducibility of standard antigen and antisera solutions was excellent during three months. The procedure provides an objective, well-controlled means for identifying clinically important enterococci from pure cultures in about 1 h. In contrast, current methods involving biochemical media require as long as 48 h.

scholarly journals CULTURE OF RED OAK VORONEZH UPLAND OAK

2020 ◽  
Vol 8 (1) ◽  
pp. 176-180
Author(s):  
Aleksey Chernodubov
Keyword(s):  
Mixed Culture ◽  
Environmental Conditions ◽  
Arable Land ◽  
Red Oak ◽  
Optimal Conditions ◽  
Optimal Density ◽  
Pure Cultures ◽  
Soil Preparation ◽  
Growing Conditions ◽  
Intensive Growth

The influence of some agrotechnical methods of planting 29-35-year-old artificial plantations of red oak on growth and productivity in the type of growing conditions – fresh substrate Was studied. Soils-gray forest loamy. It was found that the best indicators of preservation (55%) were revealed during continuous soil preparation in contrast to furrow cutting (19-32%). This is due to the optimal conditions for survival and adaptation to new environmental conditions. The optimal density of 5.6 thousand pieces per ha, which is achieved when placing 2, 5x0, 7 m. the scheme of mixing rocks is Important. In pure cultures of red oak on furrows the stock makes 132-163 m3/ha. At creation of the mixed culture of 5dkr5dch on an arable land it is respectively equal – 435 and 205 m3/ha. At the scheme of mixing of 3dkr2yao2lp2klo the stock decreases to 147 m3/ha. According to schemes of mixing the highest productivity (487-488 m3 / ha) is revealed at structure of 7dkr3b or 6dkr2yao2klo. At these compositions the most intensive growth on height and stocks of wood is noted. This is due to the fact that the red oak needs fitting breed because of its biological characteristics.

Highly Efficient Regeneration Method for Analginum-Saturated Activated Carbon

2013 ◽  
Vol 781-784 ◽  
pp. 2071-2075
Author(s):  
Zhao You Zhu ◽  
Wan Ling Wang ◽  
Li Li Wang ◽  
Ying Long Wang
Keyword(s):  
Activated Carbon ◽  
Solvent Extraction ◽  
Treatment Time ◽  
Activated Carbons ◽  
Influence Factors ◽  
Optimal Conditions ◽  
Thermal Regeneration ◽  
Extraction Step ◽  
Efficient Regeneration ◽  
Optimized Conditions

The regeneration of Analginum-saturated powdered activated carbon (PAC) using solvent extraction and thermal regeneration was investigated in detail to get the optimal conditions. In the solvent extraction step, various influence factors, such as pH of solvent, treatment time, and temperature were studied respectively. In addition, the optimal conditions of thermal regeneration were determined to be 500 °C, 120 min, with blowing N2 gas at 80 mL/min. Under the optimized conditions, the regeneration efficiency of spent PAC reached as high as 95.1%. This study provides a useful reference of regeneration method for other spent activated carbons.

scholarly journals A STUDY OF THE CROSS-REACTIVITY OF ANTIPURIN-6-OYL SERUM WITH DEOXYRIBONUCLEIC ACID (DNA)

1965 ◽  
Vol 121 (1) ◽  
pp. 19-38 ◽  
Author(s):  
Vincent P. Butler ◽  
Stuart W. Tanenbaum ◽  
Sam M. Beiser
Keyword(s):  
Deoxyribonucleic Acid ◽  
Complement Fixation ◽  
Cross Reactivity ◽  
Passive Cutaneous Anaphylaxis ◽  
Relative Order ◽  
Protein Conjugates ◽  
Precipitin Reaction ◽  
Specific Antisera ◽  
The Cross ◽  
Fixation Reaction

The specificity of the reaction of antipurin-6-oyl sera with thermally denatured DNA has been studied by means of hapten inhibition techniques. The relative order of effectiveness of various haptens as inhibitors of the complement fixation reaction between DNA and antipurin-6-oyl serum was found to be comparable to their relative order of effectiveness as inhibitors of the precipitin reaction between purin-6-oyl-protein conjugates and antipurin-6-oyl serum. Antipurin-6-oyl antibody has been purified and has been shown to be capable of reacting with thermally denatured DNA. It is concluded that the reactivity of these purine-specific antisera with DNA is a property of antibody with specificity for the purin-6-oyl moiety. In addition, the reaction between antipurinoyl sera and DNA has been demonstrated by the techniques of radioimmunoelectrophoresis and passive cutaneous anaphylaxis.

A METHOD OF TYPING HAEMOPHILUS INFLUENZAE BY THE PRECIPITIN REACTION

1948 ◽  
Vol 26e (3) ◽  
pp. 197-199 ◽  
Author(s):  
Catherine F. C. MacPherson
Keyword(s):  
Haemophilus Influenzae ◽  
Bacterial Culture ◽  
Positive Test ◽  
Clinical Material ◽  
Respiratory Pathogens ◽  
Saline Extract ◽  
Precipitin Reaction ◽  
Specific Antisera ◽  
Specific Polysaccharide ◽  
Derivatives Of

A method of typing H. influenzae by the precipitin reaction is described. The procedure consists of dissolving the bacterial culture in 90% phenol to destroy the specificity of the somatic proteins followed by alcoholic precipitation of the denatured proteins and type specific polysaccharide. The carbohydrate is extracted from the precipitate with saline and portions of the saline extract added to samples of the six type specific antisera. A positive test is indicated only by a marked turbidity, which develops within five minutes after mixing and denotes the extraction of at least 0.01 mgm. of polysaccharide. A strong positive test is, of course, regularly obtained in the case of cultures shown to be encapsulated by the usual capsular swelling technique. However, the method was devised as an attempt to ascertain whether non-typable (by the capsular swelling technique) derivatives of strains of known type or non-typable, but suspected respiratory pathogens, isolated from clinical material, contained detectable quantities of any of the known type specific polysaccharides.

scholarly journals STUDIES ON THE IMMUNOCHEMISTRY OF STREPTOCOCCAL MUCOPEPTIDE

1966 ◽  
Vol 124 (2) ◽  
pp. 155-171 ◽  
Author(s):  
Walter W. Karakawa ◽  
Richard M. Krause
Keyword(s):  
Cell Walls ◽  
Antigenic Determinant ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Amino Acid Residues ◽  
Precipitin Reaction ◽  
Peptide Moiety ◽  
Streptomyces Albus ◽  
D Cell ◽  
Group D

Streptococcal mucopeptide, solubilized by either ultrasonic treatment or lysozyme, gave a precipitin reaction with rabbit antimucopeptide serum. A haptenic inhibitor of this reaction, which was composed of alanine, glutamic acid, and lysine in a mole ratio of 4:1:1, was isolated from a Streptomyces albus enzymes digest of Group D cell walls by ion exchange chromatography. When selected antisera were employed, greater than 90% inhibition of the mucopeptide quantitative precipitin reaction was achieved with 2 mg/ml of this inhibitor, whereas a hexosamine fraction with minimal concentrations of amino acid residues was inactive in this respect. These results suggest that the peptide moiety is an antigenic determinant of mucopeptide. Preliminary results indicate that the hexosamine polymer of the mucopeptide is a secondary antigenic determinant.

scholarly journals HEMOLYTIC STREPTOCOCCUS LYMPHADENITIS IN GUINEA PIGS

1939 ◽  
Vol 70 (4) ◽  
pp. 347-359 ◽  
Author(s):  
C. V. Seastone
Keyword(s):  
Guinea Pigs ◽  
Virulent Strain ◽  
Cervical Lymphadenitis ◽  
Non Invasive ◽  
Naturally Occurring ◽  
Precipitin Reaction ◽  
Bactericidal Antibody ◽  
Pure Cultures ◽  
Highly Virulent ◽  
Infective Agent

A group of guinea pigs carrying a chronic streptococcus cervical lymphadenitis has been studied. The chronic disease may be transmitted with pure cultures of streptococci isolated from the naturally occurring abscesses. Its probable mode of transmission under natural conditions was shown to be the ingestion of the infective agent. The spontaneous appearance of an acutely fatal variant was observed. Infection with the chronic strains protected animals against the highly virulent strain. Such immunity could not be passively transferred to either mice or guinea pigs, nor could any opsonizing, precipitating, or bactericidal antibody be associated with it. The presence of allergy could not be correlated with this immunity. The dissociation of the chronic and acute strains was investigated and non-invasive phases isolated. No precipitin reaction attributable to an antigenic virulence factor could be demonstrated. No protection was obtained with vaccines or aggressins.

scholarly journals STUDIES ON THE BACTERIOPHAGES OF HEMOLYTIC STREPTOCOCCI

1958 ◽  
Vol 108 (6) ◽  
pp. 803-821 ◽  
Author(s):  
Richard M. Krause
Keyword(s):  
Cell Walls ◽  
Rabbit Antiserum ◽  
Chemical Properties ◽  
Physical Chemical ◽  
Precipitin Reaction ◽  
Streptomyces Albus ◽  
Serological Reactivity ◽  
Group A ◽  
Almost All ◽  
Enzyme Group

The lysis of cell walls of hemolytic streptococci by a phage-associated lysin has been described. A method is presented for preparing the lysin from Group C streptococcal phage lysates. Following lysis almost all of the cell wall carbohydrate is recovered in solution. This material has the serological reactivity, physical-chemical properties, and values for nitrogen, rhamnose, and glucosamine similar to those of the carbohydrate isolated from the cell walls by the Streptomyces albus enzyme. Group C carbohydrate isolated by either enzyme inactivates Group C bacteriophage. The protein liberated by the lysin from Group A Type 6 cell walls gives a type-specific precipitin reaction with homologous rabbit antiserum. Preliminary data are presented on the ammonium sulfate fractionation and the electrophoretic separation of a protein fraction with the serological reactivity of M protein.

Predicting behavior of an enzyme-linked immunoassay model by using commercially available neural network software

1993 ◽  
Vol 39 (12) ◽  
pp. 2478-2482 ◽  
Author(s):  
F T Vertosick ◽  
T Rehn
Keyword(s):  
Neural Network ◽  
Cross Validation ◽  
Optimal Conditions ◽  
Antigen Concentration ◽  
Elisa System ◽  
Feed Forward Network ◽  
Antibody Titers ◽  
Predicting Behavior ◽  
Input Variables ◽  
Network Software

Abstract Setting up new immunoassays can be a laborious and expensive task. A relatively new form of multivariate analysis known as neural networks can be applied to this problem with potential savings in reagents and technician time. Neural network software programs for personal computers are now available. We applied one such software package (Brainmaker) to a model ELISA system for measuring human serum albumin. Random combinations of four variable ELISA conditions (antigen concentration, primary and secondary antibody titers, and time for chromagen development) were used to train a three-layered feed-forward network. The trained network was then used to predict measured absorbances as a function of the four input variables in separate cross-validation sets. The network adequately predicted the effect of the input variables on the absorbance produced. With use of such methods, optimal conditions for the linear dependence of absorbance on antigen concentration can be evaluated on the computer rather than in the laboratory, with subsequent savings of time and money.

The Growth of Herpesvirus mulatto in Human Fibroblast

1974 ◽  
Vol 32 ◽  
pp. 244-245
Author(s):  
Glennelle Washington ◽  
Philip P. McGrath ◽  
Peter R. Graze ◽  
Ivor Royston
Keyword(s):  
Rhesus Monkey ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Peripheral Blood ◽  
Human Fibroblast ◽  
Rhesus Monkeys ◽  
Human Fibroblasts ◽  
Electron Microscopic ◽  
Specific Antisera ◽  
Peripheral Blood Leucocytes

Herpes-like viruses were isolated from rhesus monkey peripheral blood leucocytes when co-cultivated with WI-38 cells. The virus was originally designated rhesus leucocyte-associated herpesvirus (LAHV) and subsequently called Herpesvirus mulatta (HVM). The original isolations were from juvenile rhesus monkeys shown to be free of antibody to rhesus cytomegalic virus. The virus could only be propagated in human or simian fibroblasts. Use of specific antisera developed from HVM showed no relationship between this virus and other herpesviruses. An electron microscopic study was undertaken to determine the morphology of Herpesvirus mulatta (HVM) in infected human fibroblasts.

Amorphous silica coating on α-alumina particles

1995 ◽  
Vol 53 ◽  
pp. 210-211
Author(s):  
J. W. Mellowes ◽  
C. M. Chun ◽  
I. A. Aksay
Keyword(s):  
Amorphous Silica ◽  
Heterogeneous Nucleation ◽  
Homogeneous Nucleation ◽  
Silica Coating ◽  
Full Density ◽  
Optimal Conditions ◽  
Fine Grained ◽  
Alumina Particles ◽  
Complete Mullitization ◽  
Powder Compacts

Mullite (3Al2O32SiO2) can be fabricated by transient viscous sintering using composite particles which consist of inner cores of a-alumina and outer coatings of amorphous silica. Powder compacts prepared with these particles are sintered to almost full density at relatively low temperatures (~1300°C) and converted to dense, fine-grained mullite at higher temperatures (>1500°C) by reaction between the alumina core and the silica coating. In order to achieve complete mullitization, optimal conditions for coating alumina particles with amorphous silica must be achieved. Formation of amorphous silica can occur in solution (homogeneous nucleation) or on the surface of alumina (heterogeneous nucleation) depending on the degree of supersaturation of the solvent in which the particles are immersed. Successful coating of silica on alumina occurs when heterogeneous nucleation is promoted and homogeneous nucleation is suppressed. Therefore, one key to successful coating is an understanding of the factors such as pH and concentration that control silica nucleation in aqueous solutions. In the current work, we use TEM to determine the optimal conditions of this processing.

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