Seroepidemiology of Epstein--Barr virus-associated diseases--I. A pilot evaluation using a radiometric quantitative complement fixation test.
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Antibodies, Viral↗
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Results for “quantitative complementation”
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Complementation testing identifies genes mediating effects at quantitative trait loci underlying fear-related behavior.
Knowing the genes involved in quantitative traits provides an entry point to understanding the biological bases of behavior, but there are very few examples where the pathway from genetic locus to behavioral change is known. To explore the role of specific genes in fear behavior, we mapped three fear-related traits, tested fourteen genes at six quantitative trait loci (QTLs) by quantitative complementation, and identified six genes. Four genes, Lamp, Ptprd, Nptx2, and Sh3gl, have known roles in synapse function; the fifth, Psip1, was not previously implicated in behavior; and the sixth is a long non-coding RNA, 4933413L06Rik, of unknown function. Variation in transcriptome and epigenetic modalities occurred preferentially in excitatory neurons, suggesting that genetic variation is more permissible in excitatory than inhibitory neuronal circuits. Our results relieve a bottleneck in using genetic mapping of QTLs to uncover biology underlying behavior and prompt a reconsideration of expected relationships between genetic and functional variation.
Animals↗
Temperature-sensitive mutants of simian virus 40. I. Isolation aand preliminary characterization of B/C gene mutants.
Sixteen temperature-sensitive mutants of simian virus 40 were isolated after treatment of wild-type virus with UV light, nitrous acid, or nitrosoguanidine. All of the mutants were assigned to the B complementation group on the basis of quantitative complementation analyses. Characterization of several representative mutants revealed that under restrictive conditions such mutants produced immunologically identifiable tumor and viral capsid antigens, induced the synthesis of cellular DNA, and replicated infectious viral DNA. In addition, mutant particles produced at 33 degrees were more heat-labile than wild-type virus. This collection of mutants will be useful in an analysis of SV40 particle morphogenesis.
Animals↗
Passive immunization against Pseudomonas with a ribosomal vaccine-induced immune serum and immunoglobulin fractions.
Passive protection of mice against Pseudomonas aeruginosa using specific antisera and immunoglobulin fractions induced by immunizing rabbits with a ribosomal vaccine is reported. The results demonstrated that protection by the ribosomal vaccine against challenge with live organisms can be serum mediated. Previous work has shown that the vaccine can be separated into two components on the basis of molecular weight and that both higher (peak A)- and lower (peak B)-molecular-weight fractions were capable of inducing active immunity in mice. The present report indicates that both fractions are also capable of eliciting the production of mouse-protective antibody in rabbits. Agar gel diffusion with antisera to peaks A and B or unfractionated vaccine indicated a common antigenic component among them in addition to an extra antigen in unfractionated vaccine not present in peak B. Passive hemagglutination with antisera to peaks A and B demonstrated high-titer agglutinating antibody only with antiserum to peak A when a method of erythrocyte sensitization for lipopolysaccharide antigens was used. Also, passive hemagglutination was greatly inhibited by small amounts of lipopolysaccharide prepared from the same organism from which the vaccine was made. Both antisera to peaks A and B fixed complement with either A or B antigens. Antisera to peaks A and B, when reacted with peak B antigen, had about the same complement fixation titer (as determined by a quantitative complement fixation test). However, when peak A antigen was used, antiserum to peak A had about twice the complement fixation titer that antiserum to peak B had. These results are consistent with previous observations which suggest that the ribosomal vaccine contains lipopolysaccharide in addition to an unidentified immunogenic principle associated with ribosomes. Furthermore, this immunogen was present in both peaks A and B, but detectable amounts of lipopolysaccharide were present only in peak A. The relative importance of the immunoglobulin G (IgG) and IgM classes of antibodies was also compared. The results indicated that both IgG and IgM isolated from immune rabbit serum are protective in mice. Only IgG precipitated with the vaccine in agar gel diffusion, but both IgG and IgM were active in passive hemagglutination and in complement fixation. The passive hemagglutination titer of the IgM was higher than that of the IgG, but the complement fixation titer of the IgG was higher than that of the IgM. The mouse-protective capability of the IgG and IgM was about the same.
Animals↗
An improved quantitative micro-complement fixation test.
The technical procedures for a simple quantitative micro-complement (C) fixation test are described. Major advantages of the present technique compared with the previously described method are: a) a simple measurement of the residual hemolytic activity of C by counting the radioactivity released from 51Cr-labeled sensitized sheep erythrocytes (51Cr-EA); b) an increased sensitivity of the test, brought about by the use of a relatively small number of 51CR-EA per reaction volume; and c) an increased specificity of the test, achieved by maintaining a constant amount of C available for the specific antigen--antibody reaction.
Adenoviridae↗
Collaborative complementation study of temperature-sensitive mutants of herpes simplex virus types 1 and 2.
Twenty-three complementation groups of herpes simplex virus type 1 (HSV-1) and 20 of HSV-2 were identified by qualitative and quantitative complementation analysis from among 43 temperature-sensitive (ts) mutants of HSV-1 and 29 ts mutants of HSV-2 which had been isolated independently in 10 laboratories.
Genes, Viral↗
Duplication of the haemoglobin alpha-gene.
Gene duplication is one of the basic processes underlying evolutionary changes. The gamma-chains of human foetal haemoglobin is coded by multiple structural genes. The delta-chains of Hb A2 can be regarded as a duplication of the beta-locus. We have presented the first evidence for the presence of two major alpha-chain loci in man. The alpha-gene appears to have duplicated recently, since apart of the single point mutations characterizing Hb J-Buda and Hb G-Pest, the two alpha-gene products seem to be identical. Sensitive immunochemical measurement techniques may reveal structural differences which might escape detection by chemical methods based on differences in charge and/or chromatographic behaviour. Anti-alpha-chain sera recognizing the single amino acid substitution in alphaJ-Buda could be raised in rabbits. The anti-alpha-chain sera were found to be more powerful tools for detecting differences in the primary structure of the chain than the immune sera raised against the whole tetramer. None of the immune sera could reliably differentiate Hb G-Pest from Hb A1. The relative strength of complement fixation of the alpha-chains from haemoglobin A1 F and A2 was compared by hybridizing these human haemoglobins with caninehaemoglobin and measuring the quantitative complement fixation of the different hybrids with anti-Hb A1 and anti-alphaA1 rabbit immune sera. No antigenic difference among the alpha-chains from haemoglobins A1, A2 and F could be detected by this method either with anti-A1 or with anti-alphaA1 sera. These results do not exclude the possibility of conformational differences between the alpha-chains in native Hb A and Hb F. The antigenic activity of the alpha-chains of Hb A from normal subjects (alphaA1) and of the alpha-chains of Hb A from a double heterozygote for alphaJ-Buda and alphaG-Pest (alphaA1) were compared by the complement fixation technique. Definite differences could be detected in the relative strength of complement fixation by alphaA1 and alphaA1 with anti-alphaA1 serum. Final decision as to whether alpha-chain duplication is a universal phenomenon or whether it is restricted to only a part of mankind cannot be drawn until the presence of a silent alpha-thalassaemia gene is not excluded in some debated cases by reliable chemical methods. Measurement of alpha-globin genes in Hb H disease with cDNA enriched in alpha-globin sequences provided direct evidence that a non-thalassaemic subject has to have at least four alpha-globin genes per diploid cell.
Chromosome Mapping↗
Chemically-induced temperature sensitive mutants of dengue virus type 2. I. Isolation and partial characterization.
Temperature sensitive (ts) mutants of dengue virus type 2 (DEN-2, TH-36 isolate) were induced by replication in primary hamster kidney cells treated with 5-azacytidine. Seven ts mutants were obtained from 138 clones isolated by an immunofluorescent cloning technique. Of these 7 ts mutants, 5 were sufficiently stable to permit partial characterization. Complementation was detected at very low but statistically significant levels between some ts mutants at 40 degrees C. Viral double-stranded RNA production was evaluated in LLC-MK2 cells at 30 degrees and 40 degrees C by micro-quantitative complement fixation. The results of complementation tests and RNA production tests indicated that the 4 of 5 stable ts mutants constitute 3 separate complementation groups (2 RNA+ and 1 RNA-groups), while a fifth ts mutant was RNA- but non-complementable. The data presented here indicate that a genetic system can be developed without employing traditional plaque or cytopathology methods. Further, the 5 DEN-2 ts mutants are believed to represent the only set of complementation-positive flavivirus mutants so far isolated.
Azacitidine↗
[The induction and disappearance of complement-fixing antibodies in the blood serum of experimental animals under the antigenic action of Trichomonas vaginalis, T. hominis and T. tenax].
For studying the dynamics of induction and disappearing of complement-fixing antibodies (CFA) specific to Trichomonas vaginalis, T. hominis and T. tenax we have immunized rabbits intravenously with live individuals of the protozoa as well as intravenously, intramuscularly and subcutaneously with individuals killed at 56 degrees C. Each method of immunization was carried out by 5 inoculations with intervals of 10 days. For carrying out quantitative complement fixation we have taken blood from the ear vein of all immunized rabbits immediately before the immunization and also after it, each 10th day during one year. The dynamics of rising and lowering of titres depended on the species of trichomonads and on the method of immunization. The antigens of T. vaginalis and T. hominis induced CFA in much higher titres as antigens of T. tenax. Titres of CFA specific for all three species of above-mentioned trichomonads rose most rapidly and to the highest level when the immunization of rabbits was carried out intravenously with live individuals of protozoa. Normalization of the titres of CFA has taken place during one year at least.
Animals↗
Myeloid membrane markers. I. Expression of marker antigens specific for murine granulocytes and their precursor cells.
Bone marrow cells were investigated by immunoelectromicroscopy and by quantitative photometric immunoradioautography with a rabbit antiserum against murine bone marrow cells. The serum was absorbed with murine spleen, liver and thymus cells until it no longer reacted with thymocytes and lymph node cells in a quantitative complement fixation test. The antiserum stained granulopoietic but not erythropoietic or lymphopoietic cells. The density of the myeloid antigen on single cells increased with the differentiation from immature to mature granulopoietic cells. While the increase of label was statistically not significant at the level of differentiation from promyelocyte to myelocyte and metamyelocyte to band neutrophil, there was a remarkable gain of label from myeloblast to promyelocyte and from band neutrophil to segmented neutrophil. This was evident under the electron microscopy using peroxidase-labeled antibodies and could be measured quantitatively with photometric immunoradioautography using 125I-labeled antibodies.
Absorption↗
A quantitative micro-complement fixation method in studies of human wart viruses.
This report offers a description of a quantitative micro-complement fixation method (Cikes, 1975) for detecting human wart virus antigens and their specific antibodies, and proof of the specificity of the reactions being detected. The increased sensitivity demonstrated by chromium-release measurement is compared to the results of visual interpretation of complement fixation.
Antibodies, Viral↗
Exploring the emerging concept of precision rehabilitation: a qualitative study.
PURPOSE: This descriptive qualitative study explored knowledge users' perspectives on precision rehabilitation concepts, barriers, facilitators, and future directions as part of a convergent mixed methods scoping review. MATERIALS AND METHODS: Sixteen clinicians, administrators, and researchers from three North American tertiary care rehabilitation centers were recruited using convenience and snowball sampling to participate in individual semi-structured interviews. Conventional qualitative content analysis followed a deductive thematic approach based on predetermined categories. RESULTS: Analyses revealed three main themes: (1) Although precision rehabilitation shares foundational concepts with precision medicine, there are certain elements, such as personalization, that are uniquely expressed; (2) Rehabilitation-specific facilitators to precision approaches include the use of unobtrusive technology to collect large amounts of data in real-world contexts, while barriers include rehabilitation's typically small, heterogeneous sample sizes; and (3) The future of precision rehabilitation will require collaborative data-sharing to focus on determining care trajectories that enhance functional outcomes. CONCLUSION: Findings provide the first qualitative synthesis of knowledge users perspectives to complement quantitative evidence and inform the emerging field of precision rehabilitation.
Humans↗
Antigenic determinants of bovine myelin encephalitogenic protein recognized by rabbit antibody to myelin encephalitogenic protein.
The antigenic determinants of bovine myelin encephalitogenic protein were investigated by quantitative complement fixation and hapten inhibition using rabbit anti-monkey protein and anti-bovine protein and purified and characterized fragments of bovine protein. The two regions of bovine encephalitogenic protein containing determinants were sequences 1 to 43 and 90 to 170. One rabbit antiserum recognized a determinant(s) probably in residues 15 to 40 while for another rabbit antiserum the determinant of 1 to 43 resided in 1 to 20. The determinant(s) of residues 90 to 170 involved the region around the tryptophan at position 116. Fragment 44-89, which contains the major encephalitogenic determinant for the rabbit, was virtually devoid of any reactivity with the rabbit anti-encephalitogenic protein. It appears that portions of the protein other than the encephalitogenic site are responsible for stimulation of bone marrow-derived cells and antibody production. In demonstrating selected regions of the protein as sites for antigenic determinants, the present immunochemical studies also suggest that the protein might have a more folded conformational alignment than previously suspected.
Amino Acids↗
Antigenic similarity of morphologic type CIII1 bacteriophages.
The aim of the study was to demonstrate antigenic differentiation among bacteriophages belonging to the same morphologic type--CIII1 according to Krzywy and Slopek or A2 according to Ackermann. Twenty-six bacteriophages which multiplied on various strains of bacteria of the genera Escherichia, Shigella and Klebsiella, were studied. Serologic tests were done by the quantitative complement fixation test. Immune sera against 5 phi E. coli. D8 Sh. flexneri, G35 Sh. sonnei and Kl7 Klebsiella bacteriophages were obtained from rabbits. It was shown that bacteriophages of CIII1 morphologic type, with morphologically identical virion had different antigenic specificity. On the basis of results obtained the phages could be divided into eight serologic groups. The bacteriophages for which antisera were obtained belonged to four different serologic groups. All bacteriophages had some common antigens with 5 phi E. coli phage. The similarity points to a phylogenetic relationship among phages of CIII1 morphologic type.
Antibodies, Viral↗
Quantitation of antibody-complement mediated lysis of tumor cells.
An assay for quantitating antibody-complement mediated killing based on the release of 125I from 125IUdR labelled target cell is described. The temporal delay between antibody--complement damage and the release of nuclear material was shortened by treatment of the cells with a combination of trypsin and DNase. This treatment increased the rate of release of the labelled nuclear material from damaged cells without causing labelled nuclear material to be released from undamaged cells. The low level of spontaneous release of 125I from the target cells allows this assay to be used for experiments carried out over long time periods or in experiments involving extensive manipulations of the cells.
Animals↗
Immunologic studies in hypersensitivity pneumonitis--quantitative precipitins and complement-fixing antibodies in symptomatic and asymptomatic pigeon breeders.
Quantitative precipitation and complement fixation tests were performed on sera from a group of patients with hypersensitivity pneumonitis (pigeon breeders' disease). Their antibody levels were compared to a selected group of similarly exposed but asymptomatic subjects. The quantity of precipitating antibodies was generally greater in serum from symptomatic breeders, although quantities in the serum from some of the asymptomatic subjects were greater than that seen in ill breeders. Complement-fixing antibodies were detected in the serum of both groups. Here again, complement-fixing activity was generally greater in the serum of ill breeders. However, one asymptomatic breeder showed complement-fixing activity greater than most of the symptomatic breeder group. These findings indicate that the presence of complement-fixing antibodies per se in serum to pigeon gamma-globulin is not sufficient to cause the symptoms of pigeon breeders' disease. We suggest that other factor(s) may be involved, such as lgE- or cell-mediated hypersensitivity.
Animals↗
Comparison of several in vitro assay methods for the quantitative determination of complement consumption ('binding') by gammaglobulin preparations.
Unspecifically induced activation of Complement (C) in solution can be caused either by denatured Ig molecules and by polymeric aggregates of same or more specifically by antigen-antibody complexes. As a quality criteria, e.g. for i.v.-IgG preparations, it is agreed by the majority of people concerned that the activation of C via the classical pathway might not be unspecifically initiated. Therefore, the generally used assay systems are based on quantitating the degree of consumption of C undergoing an antigen-independent, 'frustrated' activation via the classical pathway. There are principally two different types of test modifications which were investigated: a) C is being kept constant and protein is diluted or b) protein is being kept constant and C is titrated. When a group of differing IgG preparations or IgG fragments was assayed for its so-called 'anticomplementary' activity in various already described test methods, the particular test results from the individual test methods could not unequivocally be compared with each other because some of the methods had not been optimized with regard to the amount of reagents or test substance used; only a rough estimate of the data was obtained. The value of the not standardized assays remains, therefore, questionable reasonably good and reproducible results are obtained when the amount in particular of C added as well as its quality have been adequately optimized and standardized. This allows a refined differentiation of various IgG preparations by a reliable and unadjusted quantitation of C consumption. If for example, inappropriate and not optimized rations of C amboceptor (e.g. slight C excess) was used, a suppressed C consumption was found. It seems advisable to accept prophylactic testing of anticomplementary activity for quality control as one out of several other in vitro and in vivo parameters which potentially might predict safety for the patient, the physician, and also for the producer. However, it is agreed that, irrespective of in vitro tests, in vivo testing in animals and clinical proof of safety is undoubtedly needed.
Animals↗
Direct demonstration and quantitation of the first complement component in human serum.
The first component of complement, C1, can be demonstrated and quantitated in normal and pathological human serums by simple immunochemical techniques. All of the C1q, C1r, and C1s detected in normal serum was found to be in the C1 complex. A simple modification of these methods permitted the quantitation of free C1s in the presence of macromolecular C1, a technique which may prove useful in screening pathological serums.
Calcium↗