Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “quantitative complementation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19Linked to original sources
PubMed1983

The acetylcholine system in the brain of cyclostomes with special references to the telencephalon.

The distribution of cholinergic neurons is studied in the brains of cyclostomes (Lampetra fluviatilis and Myxine glutinosa) representing an early stage of vertebrate evolution. Histochemical localization of acetylcholinesterase (AChE) is complemented by quantitative determinations of acetylcholine (ACh), cholinacetyltransferase (ChAT) and AChE. The determinations are carried out in homogenates of whole brains, the brain regions telencephalon, diencephalon, mesencephalon and medulla oblongata. The telencephalon is further subdivided and studied in more detail.The transmitter distribution found in cyclostomes is compared to data from other vertebrates. Observations on the ACh-distribution in the telencephalon are discussed with the problems of identifying telencephalic homologies.

Acetylcholine↗
PubMed1996

[Focus groups: preliminary experiences in educational health programs in Brazil].

Since 1989, the public health education section of the University of São Paulo (USP), Brazil, has been using the focus group technique to identify educational problems and evaluate programs being developed. The focus group is a research technique that allows qualitative data to be collected through group sessions involving 6 to 15 persons with some shared trait (for example, sex, age, occupation, role in the community). The group discusses various aspects of a specified subject. This paper describes five research projects in which this technique was used. The projects were carried out by professors in the School of Public Health/USP in the state of São Paulo between 1989 and 1992 with population groups and in health institutions. These experiences showed that the technique is efficient, permitting rapid identification and in-depth analysis of problems from the point of view of the population. Among the drawbacks to the technique is that it uses a small and nonrandom sample, which means that in certain cases focus groups should be considered a complement to quantitative studies. The data described here provide knowledge of perceptions, ideas, opinions, expectations, and social images-in short, the cultural and verbal universe of the population. With this information, educators and administrators can plan and evaluate education programs on the basis of the needs and views of the people they serve, putting into practice the plan to make education more democratic and responsive to the needs of its public.

Adult↗
PubMedDate not supplied

Quantitative histologic factors for grouping childhood supratentorial neuroglial tumors.

The histologic heterogeneity of childhood supratentorial neuroglial tumors, when quantified, identifies relatively homogeneous subgroups for prognostic purposes and for assignment in clinical trials. Our sample consisted of supratentorial tumors in the Childhood Brain Tumor Consortium. The data consist of reliably identified histologic features and demographic, clinical, operative, and survival information. Factor analysis was used to identify uncorrelated "factors," each represented by a different combination of histologic features in 703 tumors. The defining histologic features were used to label each factor. The heterogeneity of each tumor was summarized using the factor scores for each factor. We compared the survival estimates of subgroups of tumors within common diagnostic classes. We identified five uncorrelated quantitative factors that accounted for much of the histologic variation. Our factor labels were Jumbo, Fibrillary, Proliferative, Spongy, an Oligodendroglial. Two thirds of tumors had high scores on two or more factors, indicating a high degree of heterogeneity among these tumors. Eighty-four percent of supratentorial tumors were accounted for by 19 nonoverlapping relatively homogeneous histologic groups. The five quantitative factors complement standard qualitative taxonomies by summarizing more completely the histologic feature aspects of a tumor than by diagnosis alone and quantify the histologic heterogeneity of individual tumors. Histologically homogeneous groups of tumors are essential for clinical trials, biologic research, and prognostic models.

Adolescent↗
PubMedDate not supplied

Quantitative histologic factors for grouping childhood infratentorial neuroglial tumors.

We employed factors analysis to quantify the degree of histologic heterogeneity of childhood infratentorial neuroglial tumors. Our data were 26 reliably ascertained histologic features in 1068 children in the Childhood Brain Tumor Consortium database. The factor analysis identified five uncorrelated quantitative "factors," each derived from a different linear combination of the 26 histologic features, that accounted for much of the histologic variation. Histologic features differed in their importance in each factor. The most important features in each factor were used for naming using simple, histologic, familiar descriptive terms: Spongy, Proliferative, Ring, Fibrillary, and Nuclear. Each tumor has a score on each factor. Two-thirds of tumors had high scores for at least two factors, indicating frequent histologic heterogeneity among these tumors. Ninety-five percent of tumors were allocated to 1 of 11 nonoverlapping histologically homogeneous groups. The five quantitative factors complement standard qualitative taxonomies by making explicit the histologic heterogeneity or homogeneity of individual tumors and provide the pathologist with a method that takes advantage of more of the histology of each tumor than conventional nomenclatures. Histologically homogeneous groups of tumors are likely to be of value in clinical trials and biologic research. Prognostic models based on these factors have been published.

Adolescent↗
PubMed1971

Production of ultrastructural membrane lesions by the fifth component of complement.

A direct quantitative relationship has been demonstrated between the number of cell bound C4,2 complexes or C5 molecules and the number of ultrastructural lesions visualized on the cell membrane subsequent to immune hemolysis. When bound C4,2 complexes exceeded bound C5 molecules, the number of ultrastructural lesions seen corresponded to the number of C5 molecules. However, in the reverse situation, with bound C5 molecules in excess of bound C4,2 complexes, the latter determined the number of lesions. During the complement-reaction sequence, the lesions first became visible in the nonlytic intermediate complex EAC1,4,2,3,5 and their number was unaffected when lysis was induced by C6-C9. Since the lesions were also demonstrable on the intermediate complex EC5,6,7, it is concluded that the protein C5 is responsible for their production. Once formed, the physical presence of the C5 molecule is no longer required for the manifestation of the lesions as indicated by persistence of lesions after removal of C5 protein by trypsin. The C5-dependent ultra-structural phenomenon has therefore been interpreted to represent a true structural change of the membrane which, however, is not accompanied by a permeability defect.

Animals↗
PubMed2005

Successful plasma therapy for atypical hemolytic uremic syndrome caused by factor H deficiency owing to a novel mutation in the complement cofactor protein domain 15.

Quantitative or functional deficiency of complement factor H results in uncontrolled complement activation. This leads to thrombotic microangiopathy and finally causes renal failure (atypical hemolytic uremic syndrome [aHUS]). By regular analysis of factor H in patients with aHUS, the authors found a complete factor H deficiency in an infant in whom aHUS developed at 8 months of age. Factor H was quantified by enzyme-linked immunosorbent assay and further analyzed by Western blot using a factor H-specific antibody. Complement activation was determined by measuring total hemolytic activity of the classical (CH50) and alternative (APH50) pathways, C3 and C3d. The sequence of factor H gene was determined. Serial factor H measurements after fresh frozen plasma infusion allowed calculation of a factor H half-life. Factor H was absent in plasma (<1 mug/mL), and the complement system was highly activated (CH50, APH50, C3 decreased; C3d increased). Genetic analysis identified a novel homozygous factor H mutation (T2770A; Y899Stop) in CCP domain 15, most likely causing defective protein secretion. Time course measurements of factor H after plasma infusion established a factor H half-life of about 6 days. By repetitive plasma infusions (20 mL/kg over about 2 to 3 hours) the authors were able to interrupt the vicious circle of thrombotic microangiopathy in a factor H-deficient patient with aHUS. Based on the measured factor H half-life of about 6 days, regular plasma infusions in 2-week intervals were given, which prevented further aHUS episodes and stopped the decline of kidney function.

Complement Factor H↗
PubMed1981

Complement-dependent cell lysis assay for quantitation of rubella antibodies.

A comparison of the capacity to detect antibody titers to rubella virus was made between the complement-dependent cell lysis (CDCL) assay and the hemagglutination inhibition (HAI) test. Titers detected by CDCL assay correlated with the HAI test. Although the CDCL assay was less convenient to conduct, it proved to be more sensitive than the HAI test.

Antibodies, Viral↗
PubMed1990

[Current overview of diagnostic possibilities of complement analysis].

The complement system is composed of at least 21 serum proteins and 8 cell surface receptors sensitive to complement components or their fragments. Qualitative and quantitative analysis of complement components in clinical samples has become standard procedure in many laboratories thanks to the availability of easy-to-perform test kits. However, interpretation of results is still a task that requires great skill and the situation are rare, in which analysis of the complement system goes beyond diagnosis into therapeutic consequences. The present paper is an update of previous similar reviews now available in the international literature; in addition, the author attempts at bringing the often complicated world of complement and clinical practice together and thus contributes to answering the question: what should the clinician know about complement?

Antigen-Antibody Complex↗
PubMed2002

Vanaso is a candidate quantitative trait gene for Drosophila olfactory behavior.

Most animals depend on olfaction for survival and procreation. Odor-guided behavior is a quantitative trait, with phenotypic variation due to multiple segregating quantitative trait loci (QTL). Despite its profound biological importance, the genetic basis of naturally occurring variation in olfactory behavior remains unexplored. Here, we mapped a single Drosophila QTL affecting variation in avoidance response to benzaldehyde, using a population of recombinant inbred lines. Deficiency complementation mapping resolved this region into one female- and one male-specific QTL. Subsequent quantitative complementation tests to all available mutations of positional candidate genes showed that the female-specific QTL failed to complement a P-element insertional mutation, l(3)04276. The P-element insertion was in the intron of a novel gene, Vanaso, which contains a putative guanylate binding protein domain, is highly polymorphic, and is expressed in the third antennal segment, the major olfactory organ of Drosophila. No expression was detected in the fly brain, suggesting that Vanaso plays a role in peripheral chemosensory processes rather than in central integration of olfactory information. QTL mapping followed by quantitative complementation tests to deficiencies and mutations is an effective strategy for gene discovery that allows characterization of effects of recessive lethal genes on adult phenotypes and here enabled identification of a candidate gene that contributes to sex-specific quantitative variation in olfactory behavior.

Amino Acid Sequence↗
PubMed1985

Anti-peripheral myelin antibody in patients with demyelinating neuropathy: quantitative and kinetic determination of serum antibody by complement component 1 fixation.

The role of anti-peripheral nerve myelin antibody (anti-PNM Ab) in the pathogenesis of acquired demyelination of peripheral nerve is unclear, in part, due to the poor correlation between antibody and disease activity. Previous studies show that only 27-50% of patients with acute demyelinating neuropathy or Guillain-Barré syndrome (GBS) had serum Abs to peripheral nerve or PNM as demonstrated by consumption of hemolytic activity of serum complement 1 (C1) fixation and transfer assay, quantitative determinations of anti-PNM Ab showed significantly high titers in the serum of patients with GBS, chronic and recurrent polyneuritis, and paraproteinemia associated with peripheral neuropathy. All 11 patients with acute-phase GBS had Ab titers 6-56 times higher than controls. In 6 GBS patients, serial Ab determinations showed that titers were highest on admission, fell rapidly the first week, and became undetectable or barely detectable by the third week. Declining Ab titers coincided with cessation of clinical progression. In 3 GBS patients, depletion of serum IgM lowered anti-PNM Ab titers significantly, whereas IgG depletion failed to produce a similar effect. This study shows that the C1 fixation and transfer assay is a sensitive method to detect anti-PNM Ab in the serum of patients with a variety of demyelinating neuropathies and provides good correlation between Ab level and the clinical course of GBS patients. It may provide important information about the pathogenesis of the demyelinating neuropathies.

Antibodies↗
PubMed1985

Double fluorescence technique for measurement of complement-fixing antibody to lymphocyte subsets.

A double fluorescent antibody method for quantitating human complement-fixing antibody to lymphocyte subclasses has been developed. The indicators in this system are a C6-deficient serum as a non-lytic source of complement, rhodamine-labeled anti-C3 and fluorescein-labeled murine monoclonal antibodies to human lymphocyte subsets. The basic procedure is to incubate lymphocytes with the unknown serum and then to add C6-deficient serum. The binding of C3 is indicated by staining with rhodamine-labeled anti-C3 and the subset class of the lymphocyte so stained is determined by binding of fluorescein-tagged anti-OKT4 or -OKT8 antibodies. The occurrence of both red and green cell surface fluorescence denotes the presence of a complement-binding antibody to the lymphocyte subset defined by the monoclonal antibody. In addition to defining the specificity of complement-fixing anti-lymphocyte antibodies, this technique is more sensitive than the microcytotoxicity assay.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Quantitation of C3 nephritic factor of alternative complement pathway by an enzyme-linked immunosorbent assay.

We have developed an enzyme-linked immunosorbent assay (ELISA) for the quantitation of C3 nephritic factor of the alternative pathway of complement (NeFA). Incubation of the NeFA-positive serum (patient KS serum) with normal human serum (NHS) in Mg-EGTA resulted in the formation of C3-B-IgG complex. No complex was formed in EDTA. At first this was detected as three types of complexes: C3-IgG, B-IgG and B-C3, by the combination of antibodies. The reaction mixture in Mg-EGTA was filtered through an ACA 22 column, from which the complexes were eluted in the same part as the first protein peak. When IgG purified from KS serum was incubated with NHS in Mg-EGTA, B-C3 complex increased in proportion to the dose of IgG. These results indicated that only one kind of complex consisting of IgG, C3 and B (IgG-C3-B) was generated by the addition of NeFA to NHS. Serum NeFA could be quantified as the titer of B-C3 complex formed after its incubation with NHS in Mg-EGTA. Using the ELISA method, NeFA was positive in five out of six patients with membranoproliferative glomerulonephritis (MPGN) type II and in only one of 17 with MPGN type I. Titers obtained by the new method were in good accordance with those by C3 conversion and C3bBb stabilization assays for NeFA, and the new method was more exact and simple than the conventional methods.

Antigen-Antibody Complex↗