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Results for “quantitative complementation”

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PubMed1976

The differential diagnosis between preeclamptic toxemia and glomerulonephritis in patients with proteinuria during pregnancy.

The renal biopsies from 123 patients who presented with proteinuria during pregnancy have been reviewed. Forty-seven showed glomerulonephritis that could be diagnosed on morphological grounds or on a clear-cut history of urine abnormalities before pregnancy. Fifty of the remaining 76 had been followed after pregnancy. In these 50 patients, a retrospective diagnosis of glomerulonephritis or preeclamptic toxemia was based on the persistence or disappearance of proteinuria and/or hematuria three or more months after pregnancy. Among 22 in whom a biopsy diagnosis of "pure" preeclamptic toxemia had been made, 19 showed disappearance of urine abnormalities after pregnancy, thus confirming the biopsy diagnosis. A retrospective analysis showed focal and segmental glomeris group but none in the preeclamptic toxemia group. Other differences could not be defined without quantitative evaluation; however, the glomeruli appeared to be more cellular in the glomerulonephritis group. The presence of IgA, IgG, IgM, Complement, and fibrin was not of value in distinguishing glomerulonephritis from preeclamptic toxemia.

Arteries↗
PubMed2005

[Nucleic-acid based diagnostics in clinical microbiology].

BACKGROUND: Detection of nucleic acids from infectious agents now has a fundamental role in diagnostic microbiology laboratories. Nucleic acid amplification methods have promoted this development. MATERIAL AND METHODS: In this study we give a review of the field based on searches in Medline and our own experience. RESULTS AND INTERPRETATION: Nucleic acid sequencing, hybridisation and electrophoresis complement the gene technology available for microbiological diagnosis. Recently, equipment for automated extraction of nucleic acids and real-time quantitative PCR has contributed to faster, more reliable and robust nucleic acid detection. An increasing number of microbiological agents and virulence genes can now be diagnosed in a variety of patient samples and supplemented with additional nucleic acid-based methods for genotyping and quantitative monitoring of drug resistance and therapeutic response.

Bacterial Infections↗
PubMed2006

An example of demographic anthropology, the study of matrimonial exchanges--endogamy, choice of spouse and preferential marriage.

The development of demographic studies in anthropology is directly linked to the success of population genetics. The anthropodemographic or anthropogenetic approach is thus underpinned by questions of genetics. While demographers focus on population dynamics and renewal in quantitative terms, population geneticists refer not to individuals but to the sets of genes carried by individuals in a population. Their aim is to detect the factors and processes which influence the genetic evolution of a group, i.e. which modify gene frequencies from one generation to the next. Among them are the factors which affect modes of reproduction. To illustrate the association of these three approaches, i.e. demographic, anthropological and genetic, I use here the example of matrimonial exchanges--which lie at the heart of the population renewal process--among the Dogon of Boni, a Malian ethnic group living in the southern Sahel. We can see how successive analyses--starting with endogamy at macroscopic level and moving down to the individual with choice of spouse and preferential marriage-- combining both quantitative and qualitative approaches, can be used to obtain a detailed description of matrimonial exchanges which shed light upon and complement the three different viewpoints.

Demography↗
PubMed1984

Gene dosage and complementation analysis of ataxia telangiectasia lymphoblastoid cell lines assayed by induced chromosome aberrations.

An approach of general applicability to mammalian radiosensitive mutants has been used in the analysis of gene dosage and complementation in ataxia telangiectasia (A-T). Thymidine residues in DNA of one parental lymphoblastoid cell line were substituted with bromodeoxyuridine before fusion with a second parental cell line, to allow differential staining of the two sets of chromosomes. Following gamma-irradiation, induced chromosome aberrations were scored in diploid and homokaryon cells from each parental line as well as in heterokaryons. Four complementation groups were ascertained among 7 A-T cell lines. Analysis of heterokaryons formed between appropriate combinations of normal, A-T homozygote and A-T heterozygote cells, gave a quantitative measure of gene dosage and demonstrated increasing radiosensitivity with increasing numbers of A-T alleles.

Ataxia Telangiectasia↗
PubMed1977

Evidence for monoclonal proliferation in prolymphocytic leukemia of T-cell orgin. A cytogenetic and Quantitative immunoautoradiographic analysis.

B- and T-cell markers were studied in a patient with prolymphocytic leukemia, a rare variant of chronic lymphocytic leukemia. Thymus-derived features were identified on the membrane of the neoplastic lymphocytes using the following cellsurface markers: Heterologous T-cell antigen, sheep erythrocyte receptor, surface immunoglobulin, complement receptor, Fc receptor and mouse erythrocyte receptor. Cytogenetic studies of leukemic cells from unstimulated and mitogen-stimulated cultures revealed a consistent karyotype characterized by marker chromosomes and a decreased chromosome number, whereas chromosomal analysis of hair root cells yielded a normal karyotype. A uniform expression of T-cell antigens measured on single leukemic cells by quantitative microphotometric immunoautoradiography correlated with the cytogenetic findings which are compatible with a descent from one progenitor cell.

Aged↗
PubMed1990

Complement-mediated antibody-dependent enhancement of HIV-1 infection requires CD4 and complement receptors.

In this study it is demonstrated that complement-mediated antibody-dependent enhancement (C'-ADE) of HIV-1 infection in vitro is blocked by murine monoclonal antibodies to CD4 and complement receptor type 2 (CR2) while HIV-1 infection in the absence of C'-ADE is blocked by anti-CD4 but not anti-CR2 monoclonal antibodies. The anti-CR2 murine monoclonal antibody, OKB7, blocked C'-ADE of HIV-1 infection at concentrations greater than 1 microgram/ml. The anti-CD4 monoclonal antibody, OKT4a, but not OKT4f blocked C'-ADE at concentrations greater than 0.06 microgram/ml. HIV-1 infections were quantitated by cytopathic effect, indirect immunofluorescence, and reverse transcriptase release. It appears from these in vitro studies that C'-ADE of HIV-1 infection requires both CD4 and complement receptors while HIV-1 infection in the absence of antibody and complement requires only CD4.

Antibodies, Monoclonal↗
PubMed1978

Passive immune haemolysis -- a class specific antibody assay for use in the pig.

An antibody assay is described based on the principle of complement mediated lysis of sheep red blood cells labelled with antigen. The technique provides a sensitive class specific assay enabling antibody in all three major immunoglobulin classes to be quantitated independently. The assay may be performed in tubes allowing precise measurement of antibody concentration, or in microtitre plates which provides a rapid estimation of antibody titre.

Animals↗
PubMed2005

A rice quantitative trait locus for salt tolerance encodes a sodium transporter.

Many important agronomic traits in crop plants, including stress tolerance, are complex traits controlled by quantitative trait loci (QTLs). Isolation of these QTLs holds great promise to improve world agriculture but is a challenging task. We previously mapped a rice QTL, SKC1, that maintained K(+) homeostasis in the salt-tolerant variety under salt stress, consistent with the earlier finding that K(+) homeostasis is important in salt tolerance. To understand the molecular basis of this QTL, we isolated the SKC1 gene by map-based cloning and found that it encoded a member of HKT-type transporters. SKC1 is preferentially expressed in the parenchyma cells surrounding the xylem vessels. Voltage-clamp analysis showed that SKC1 protein functions as a Na(+)-selective transporter. Physiological analysis suggested that SKC1 is involved in regulating K(+)/Na(+) homeostasis under salt stress, providing a potential tool for improving salt tolerance in crops.

Base Sequence↗
PubMed1987

Quantitation and antigenic characterization of bound C3 of circulating immune complexes in systemic lupus erythematosus, rheumatoid arthritis, and primary biliary cirrhosis.

In recent years defective function of the complement-mediated clearance of immune complexes (IC) has been reported in patients with immune complex disease. The defect has been found at different levels in the clearance system. An important event in this sequential system is the binding of C3-coated particles to C3 receptors on erythrocytes and phagocytes. This study focuses on immunochemical properties of IC-bound C3 that reflect the functional state of the molecule. Sera from patients with primary biliary cirrhosis (PBC), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE) and from normal subjects were analyzed for their level of C3 precipitable in 2.7% (w/v) polyethylene glycol (PEG). The mean levels for the patient categories were significantly higher than that for the normal subjects. The immunochemical study revealed several differences among the different forms of PEG-precipitable C3. All forms expressed C3(D) antigens which are expressed by immune complex-associated and denatured forms but not by soluble physiological forms of C3. The expression of these antigens was proportionately lower for the complex-associated C3 of PBC compared to that of RA and SLE. Furthermore, employing monoclonal anti-C3(D) antibodies against the C3c and the C3d domain, distinct differences could be detected among all forms of PEG-precipitable C3. Sera from RA and SLE, in particular, contained PEG-precipitable C3 that exhibited distinctive immunochemical features with respect to these epitopes.

Antibodies↗
PubMed1980

Quantitative determination of circulating immune complexes by inhibition of the hemolytic activity of polyclonal IgM rheumatoid factor.

A practical and sensitive method for detection and quantification of soluble complement-fixing immune complexes in sera of patients with various disease states has been developed. The assay is based on inhibition of complement-dependent sheep red cell hemolysis mediated by polyclonal IgM rheumatoid factor. Aggregated human IgG was used as an in vitro model of C-fixing human immune complexes and was quantified by its ability to inhibit hemolysis of sensitized sheep red cells by isolated IgM rheumatoid factor. The limit of sensitivity of this assay was 1--3 micrograms/ml. Fixation of complement in competition with isolated IgM rheumatoid factor, resulting in inhibition of hemolysis of sensitized sheep red cells, was used for detection and quantification of immune complexes in human sera. IgM rheumatoid factor was incubated with sensitised sheep red cells followed by addition of test sera; guinea pig complement was added; and the amount of IgM rheumatoid factor mediated hemolysis was determined spectrophotometrically and referred to a standard curve of inhibition of hemolysis by increasing amounts of aggregated human gamma-globulin. Good discrimination between sero-positive rheumatoid arthritis and systemic lupus erythematosus patients compared with normal and hospitalized subjects was found.

Antigen-Antibody Complex↗
PubMedDate not supplied

Quantitation of T cell depletion by limiting dilution analysis.

BACKGROUND: We evaluated a culture method for enumeration of residual T cells remaining in marrow after treatment with antibody and complement or with immunotoxin. METHODS: Marrow cells were cultured at limiting dilutions with phytohemagglutinin in the presence of Epstein Barr virus transformed human lymphoblastoid cells, and supernates were tested three days later for IL-2 by a cell proliferation assay. This method provides a simple, reliable, objective and rapid enumeration of T cells in marrow before and after treatment. RESULTS: Approximately 6% of untreated marrow mononuclear cells can produce IL-2 in such clonal cultures. Treatment with antibodies and complement under conditions identical to those used for our previous clinical trials produced a 3.7 log depletion of IL-2 precursors, whereas treatment with a ricin A chain anti-CD3 immunotoxin produced a 3.0 log depletion. CONCLUSIONS: Clinical correlations are in progress for assessing whether T cell depletion evaluated with the present method equals previous techniques. The extreme depletion of T cells accomplished by these methods may partly account for the high graft failure rate seen in our clinical trials.

Antibodies, Monoclonal↗
PubMed1988

Altered replicase specificity is responsible for resistance to defective interfering particle interference of an Sdi- mutant of vesicular stomatitis virus.

The in vitro resistance of an Sdi- mutant of vesicular stomatitis virus to interference by wild-type defective interfering (DI) particles was expressed quantitatively in a cell-free replication system derived from mutant-infected cells. Added wild-type DI particle templates were replicated very poorly by extracts of Sdi- mutant-infected cells. However, the addition of purified viral polymerase (a complex of L and NS proteins) from wild-type vesicular stomatitis virus allowed efficient replication of wild-type DI particle genomes in these cell extracts. Added wild-type NS protein alone did not complement DI particle genome replication in these cell extracts, but it did complement a defect in the in vitro transcriptional activity of Sdi- mutant virus. These results clearly implicate the vesicular stomatitis virus polymerase complex in the inability of Sdi- mutants to replicate DI particles and in the quantitative escape from DI particle interference in evolving virus populations.

Animals↗
PubMed1990

Expression of complement alternative pathway proteins by endothelial cells. Differential regulation by interleukin 1 and glucocorticoids.

We have studied the secretion of proteins of the alternative pathway of complement C3, factor B and factor H by human umbilical vein endothelial cells (HUVEC). Results showed that factor H and factor B are quantitatively secreted in abundance whereas C3 could only be detected when the cells are maintained in culture during long periods of time. Interferon-gamma stimulated factor H, factor B and, to a lesser extent, C3 secretions. Interleukin (IL) 1 had a differential effect on spontaneous C3, factor B and factor H secretions. In the presence of IL 1, there was a significant secretion of C3 occurring within a short period of culture. IL 1 also stimulated factor B secretion. There was a synergistic stimulating effect between IL 1 and interferon-gamma to bring C3 and factor B productions by HUVEC to very high levels. In contrast, factor H secretion was consistently inhibited by IL 1. Local increase in C3 and factor B secretions by endothelial cells in the presence of IL 1 may have important implications in the inflammatory reaction. In striking contrast, the glucocorticoid dexamethasone (DXM) had modulatory effects which are consistent with its anti-inflammatory properties. DXM, at therapeutic concentrations, decreased C3 and factor B secretions and increased factor H secretion. Local modulation of complement protein secretion by DXM appears to be a new mechanism by which this glucocorticoid may control inflammation.

Complement C3b Inactivator Proteins↗
PubMed1981

51cr-release assay for quantitation of membrane bound and solubilized Thy-1 antigen.

A method for quantitative determination of mouse Thy-1 antigen is presented. Antigen to be assayed is incubated with anti-Thy-1 serum and remaining antibody activity is measured by adding 51Cr-labelled thymocytes and complement. The detection limit corresponds to the amount of Thy-1 antigen exposed on the surface of 25,000 thymocytes, which can be calculated to correspond to approximately 0.5 ng. The assay was designed to be performed in the presence or absence of detergent, and is therefore a useful tool for quantitation of Thy-1 in purification procedures and studies on the biological significance of this membrane antigen.

Animals↗
PubMed1993

Identification and quantification of complement regulator CD46 on normal human tissues.

CD46 is a cell-surface regulatory molecule that prevents lysis of autologous human cells by activated complement. It has been well characterized on leucocytes, reproductive cells and various cultured cell lines and is considered to be ubiquitously expressed. We now extend these analyses and describe CD46 in a variety of different human tissues. Strong expression was observed by immunohistology on epithelial cells lining exocrine ducts and glands, such as salivary gland and pancreas and on kidney tubules and glomerular epithelium. Quantitative tissue expression was measured by radioimmunoassay and confirmed histological observations. Thus, CD46 is highly expressed on cells in contact with extracellular fluids thought not to contain large quantities of complement but which may still be subjected to complement attack thereby necessitating the presence of complement regulators to prevent non-specific destruction of cells.

Antigens, CD↗
PubMed2003

Tumor cell-collagen interactions: Identification and semi-quantitative evaluation of selectively-expressed genes by combination of differential display- and multiplex-PCR.

It is widely acknowledged that the presence of extracellular matrix components as substrates can drastically modulate the phenotype and gene expression of cultured cells, including tumor cells. A number of published reports indicated that substrates made from two peculiar collagen species, i.e. type V and OF/LB, which are abnormally deposited in the stroma of primary ductal infiltrating carcinoma (d.i.c.) of the breast "in vivo," were able to exert marked and opposite effects on "in vitro" viability, growth and invasiveness of the 8701-BC cell line, isolated from d.i.c.-affected breast epithelium. To complement such functional data on the effect of cell-collagen interactions with information at molecular level, we have utilized a combination of differential display- and semi-quantitative multiplex-PCR techniques with the aim of detecting variations in the expression levels of selected genes by cells maintained in either culture condition. Here we report some prototypical data on the identification and semi-quantitation of three of the differentially-amplified PCR products found, i.e. HSP2A and MSF-B which are up-regulated in cells grown onto OF/LB collagen substrate, and SRCAP which is prominently down-regulated in the presence of type V collagen substrate. This protocol represents a powerful tool for evaluating changes in the levels and patterns of gene expression which can be theoretically adapted to any experimental model system.

Journal Article↗