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PubMed1975

[Studies on cross reactions of antisera against nucleotid-protein conjugates with denaturated desoxyribonucleic acids].

The reactivity of anti-nucleotide-sera (anti-UMP, anti-AMP, anti-GMP) with denatured DNA's of 10 different sources was investigated by means of quantitative complement fixation. The haptene specificity of the anti-nucleotide antibodies was shown by haptene inhibition of the reaction with DNA. Anti-UMP showed cross-reactions with other pyrimidine-derivatives, but to a lesser extent; anti-GMP cross-reacted with adenine structures. Quantitative differences were observed in the reaction of anti-UMP, anti-AMP and anti-GMP with DNA's of various (G + C)-contents. These differences could not be correlated in all cases with the overall base composition of the DNA.

Animals↗
PubMed1969

Breakdown products of C 3 in human synovial fluids.

Activation of the complement sequence results in conversion of the third component of complement (C'3) to an inactive product (C'3i) and the elaboration of additional fragments of smaller molecular weights and faster electrophoretic mobilities. Immunoelectrophoretic analysis of fresh synovial fluids with an anti-human C'3 antiserum disclosed in some a variable degree of conversion of C'3 to C'3i, but a more striking finding was an additional line in the alpha-globulin region. This faster migrating protein gave a reaction of partial identity with C'3/C'3i. With this antiserum a similar pattern developed when fresh human serum was incubated with immune complexes, or aggregated gamma-globulin. The same breakdown product of C'3 was obtained by treatment of fresh human serum with Zymosan, ammonium, hydrazine, agar, or dextran. Heating serum at 56 degrees C for 1 hr destroys the breakdown product; aging of serum produces it. Breakdown products of C'3 were looked for in 49 synovial fluids from patients with a variety of joint diseases. A significant correlation was found between the demonstration of the fast migrating breakdown product of C'3 and the diagnosis of rheumatoid arthritis and the presence of rheumatoid factor. A similar immunoelectrophoretic pattern was not found in the serum of any of the patients studied. When human gamma-globulin, which has been reduced and alkylated, is heat aggregated it loses the ability to fix human complement but still reacts with rheumatoid factor. Addition of reduced, aggregated gamma-globulin to fresh normal human serum produced no conversion of C'3, but when incubated with serum containing a high titer of rheumatoid factor, there was conversion of C'3 and the appearance of a breakdown product. Quantitative complement fixation studies with fresh serum from normal subjects and patients with rheumatoid arthritis disclosed complement fixation by reduced, aggregated gamma-globulin. The per cent of complement fixation was proportional to the titer of rheumatoid factor present in the test serum. These findings were interpreted as showing that rheumatoid factor can fix complement.The possibility is discussed that the presence of breakdown products of C'3 in the synovial effusions of most patients with seropositive rheumatoid arthritis and the ability of rheumatoid factor to fix complement are related phenomena.

Animals↗
PubMedDate not supplied

[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↗
PubMed1977

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↗
PubMedDate not supplied

Health promotion through healthy public policy: the contribution of complementary research methods.

The focus of the "new public health" is moving from the level of individuals to the level of organizations, communities, and broader social policies. Traditional quantitative methods which are appropriate at the level of individual behaviour change, require adaptation and refinement when sociopolitical change becomes the mechanism for health promotion. Because of their training and experience, health services researchers and health educators, especially psychologists, are understandably resistant to making necessary methodologic changes. Well-designed and carefully conducted qualitative studies, using techniques such as ethnographic interviews, participant observation, case studies, or focus group activities, are required to complement quantitative approaches. These studies can fill gaps where quantitative techniques are suboptimal or even inappropriate. Hard qualitative techniques can also support soft quantitative methods. Their utility in process evaluation is now beyond dispute. Recent work at the New England Research Institute is used to illustrate the role of qualitative research in the evaluation of health promotion through planned sociopolitical change.

Health Policy↗
PubMed1970

Genetic characteristics of conditional lethal mutants of vesicular stomatitis virus induced by 5-fluorouracil, 5-azacytidine, and ethyl methane sulfonate.

One hundred and seventy-five temperature-sensitive (ts) mutants of vesicular stomatitis virus (type Indiana-C) induced by 5-fluorouracil (FU), 5-azacytidine (ACR), and ethyl methane sulfonate (EMS) have been assigned to four complementation groups by a qualitative test. Group I contains 151 mutants; group II, 2 mutants; group III, 1 mutant; and group IV, 15 mutants; 6 are unclassified. FU was much more effective as a mutagen than either ACR or EMS. The proportion of the mutants belonging to groups I and IV, however, was similar in the case of all three mutagens. Fifteen mutants from groups I and IV have been used to obtain quantitative complementation data. Both groups appear to be homogeneous. Complementation yields increase with increasing multiplicity, but the number of particles per cell required to elicit maximal complementation is small. The pattern of genetic recombination parallels that of complementation. No recombination could be detected in crosses within group I (<0.001%) or group IV (<0.07%), whereas recombination (0.31 to 3.4%) was observed in crosses between groups I and IV. Recombination frequency did not increase with multiplicity above an input of 0.6 plaque-forming units per cell. Many group I mutants have very low reversion rates, and BHK 21 clone 13 cells infected with one of these mutants have been "cured" of infection by prolonged exposure at the restrictive temperature.

Animals↗
PubMed1975

Quantitative determination of antibody in idiopathic thrombocytopenic purpura. Correlation of serum and platelet-bound antibody with clinical response.

We studied the clinical applicability of a recently developed technic that determines antiplatelet antibody directly on the platelet surface or in serum. The technic is a quantitative complement lysis-inhibition assay. Normal platelets have less than 0.4 pg of surface IgG. All patients with idiopathic thrombocytopenic purpura who were studied had greater than that value. Surface IgG was increased in inverse proportion to the platelet count. Surface levels of greater than 1.1 pg correlated with failure to respond to prednisone therapy. Incubation of normal serums with normal platelets did not increase surface IgG of such platelets, but the incubation with thrombocytopenic serums increased their surface IgG 0.5 to 100 times. The degree of increase did not predict response to treatment. However, quantitation of surface IgG of thrombocytopenic platelets was useful in predicting response to treatment.

Absorption↗
PubMed1986

Micro-complement fixation: a quantitative estimator of protein evolution.

The quantitative immunological technique of micro-complement fixation (MC'F) has been routinely used during the past decade to assess evolutionary relationships among living vertebrate species. The large data base that has been generated, along with the excellent correlations between immunologically measured genetic distances and paleontologically derived estimates of divergence times, have formed the basis for the albumin molecular clock. Immunological distance (ID) involves a logarithmic transformation of experimentally measured antibody concentrations. The justification for this transformation has rested entirely on empirical correlations. Consequently, several other transformations have been proposed as giving better fits to particular data sets. We derive, from first principles, the relationship between ID and the amino acid sequence replacements (AAR) between compared albumins. ID is shown to be a linear estimator of AAR. This ID-AAR relationship is based on a proposed process of antibody assortment and exclusion. We present experimental data confirming that such an antibody assortment-exclusion process occurs in MC'F. This process can explain both the high sensitivity and the quantitative phylogenetic nature of the MC'F assay. The assortment-exclusion process also predicts a divergence limit beyond which MC'F data no longer provide robust phylogenetic data.

Biological Evolution↗
PubMed1978

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↗
PubMed1991

Rapid appraisal in an urban setting, an example from the developed world.

Rapid Appraisal has been used as a method to understand communities' own perceptions of their priority needs. It can be used as a tool for formulating joint action plans between communities and service planners and managers. It can also be used to complement quantitative methods of assessing needs by more in-depth qualitative understanding of socio-cultural perspectives. In the example described in this paper Rapid Appraisal is used both as action research and as a qualitative tool in order to define health and social needs of an urban, deprived community in England.

Community Health Services↗
PubMed1977

Evidence for a common tumour-associated antigen in extracts of human bronchogenic carcinoma.

Xeno-antiserum specific for antigenic components of bronchogenic carcinoma was raised in rabbits, by passively immunizing them to normal human lung antigens at the same time as immunization with a tumour extract from a squamous-cell carcinoma. Antiserum so raised contained minimal quantities of anti-normal antibody which could be removed by a single absorption with glutaral-dehyde-insolubilized normal lung extract. When tested by quantitative complement fixation with a panel of tumour extracts from surgical specimens, it was found that the antiserum gave positive complement fixation with all squamous-cell carcinoma extracts tested, and with some of the extracts from bronchogenic carcinomas of differing pathological types. The antiserum was essentially negative for pooled extracts from normal lung, liver and spleen but gave a weak positive reaction with an extract of pooled foetal lung tissue.

Antibodies, Neoplasm↗
PubMed1970

Immunochemical measurement of double-stranded RNA of uninfected and arbovirus-infected mammalian cells.

A quantitative complement fixation assay which specifically measures double-stranded RNA has been used to study this RNA extracted from uninfected and arbovirus-infected cells. The double-straned RNA of the uninfected BHK-21 cells sedimented in the 12S region in sucrose gradients. The double-stranded RNA of Sinbis virus-infected cells, as measured immunochemically, included a predominant peak at 12S, a smaller 18S peak, and polydisperse material extending into the 26-30S region. All classes of this RNA detected immunochemically showed a sharp thermal denaturation curve, and increased in amount progressively during infection, with the 12S peak predominant at all times.

Animals↗
PubMed1971

Detection of Australia antigen by radioimmunoassay.

A double-antibody radioimmunoassay has been developed for the detection of Australia antigen and antibodies to Australia antigen in human sera. The assay is simple to perform, and can be completed in 18 hr. Based on parallel studies of human sera, it is approximately 2000 times more sensitive than agar gel diffusion and 200 times more sensitive than quantitative complement fixation. Australia antigen or antibody to Australia antigen was demonstrated in 22 of 23 single serum samples obtained from patients acutely ill with the long-incubation form of hepatitis; eight of the sera were negative when evaluated by less sensitive techniques.

Animals↗
PubMed1985

Interleukin 2 promotes growth and cytolytic activity in human T3+4-8- thymocytes.

Human thymocytes bearing T3 but neither T4 nor T8 antigens (T3+4-8- cells) were obtained after negative selection of thymocytes, either fresh or cultured in medium containing recombinant interleukin 2 (IL-2), by treatment with Na1/34, OKT4A and B9.4 monoclonal antibodies (which recognize T6, T4, and T8 antigens, respectively) and complement. Quantitative flow cytometry showed a 98% pure population of T3+4-8- lymphocytes, which included proliferating cells. The growth and maturation requirements of these thymocytes were characterized and related to the T3-receptor complex and IL-2 pathways, thought to be used by mature lymphocytes. The results show that addition of recombinant IL-2 promotes, in a dose-dependent way, proliferation and acquisition of effector functions by cultured T3+4-8- thymocytes, the growth being inhibitable by monoclonal antibody 33B73 (anti-Tac). Furthermore, cytolytic activity of T3+4-8- cells induced by recombinant IL-2 is specifically blocked by monoclonal antibody OKT3, showing that it operates via the T3-receptor complex and does not require either T4 or T8 molecules. The finding of in vitro responsiveness to recombinant IL-2 in T3+4-8- thymocytes suggests a role of IL-2 in the growth and maturation of cells committed to the T-cell lineage, during intrathymic differentiation, prior to expression of T4 and T8 molecules.

Antibodies, Monoclonal↗
PubMed2026

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↗
PubMed1975

Yersinia pestis: correlation of ultrastructures and immunological status.

Ultrastructural identification and localization of the fraction 1 "envelope" antigen in the plague bacillus Yersinia pestis were the primary objectives of this brief study. The antigenicity of extra-cellular material between the bacilli in undisturbed cultured colonies and that of the pathogen per se were measured and correlated by means of the semi quantitative complement fixation method after incubation for 72 h at 37 C. When the amount of extracellular substance in wild-type T1 (virulent) bacteria was compared by electron microscopy with that in avirulent strains of Y. pestis, with and without passage through guinea pigs, we found that the material of interest was greatly attenuated or even absent in colonies that had not been passed through animals, whereas passage markedly augmented production of the material. We also explored the requirement for larger quantities of Ca(2+) and Mg(2+) in the culture media and discovered that without these ions production of the extracellular material was limited. These observations support the hypothesis that this extracellular substance between cultured Y. pestis bacilli of various strains represents the source of the fraction 1 envelope antigen.

Antigens, Bacterial↗
PubMed1973

Genetic study of suppressor-sensitive mutants of the Bacillus subtilis bacteriophage phi 29.

With bacteriophage phi29 of Bacillus subtilis 133, suppressor-sensitive (sus) hydroxylamine mutants have been isolated. Intracistronic and intercistronic quantitative complementation placed the mutants in 13 cistrons, and three-factor crosses have been used to assign an unambiguous order for 10 cistrons. Recombination frequencies have been presented for several regions of the genome to facilitate comparison of the sus system with the previously published temperature-sensitive mapping systems.

Bacillus subtilis↗
PubMed1974

Murine type-C virus group-specific antigens: interstrain immunochemical, biophysical, and amino acid sequence differences.

The 30,000-molecular-weight internal protein, p30, was purified from seven strains of mouse type-C viruses. The individual p30's showed variation in isoelectric points and also intrastrain heterogeneity. The individual p30's could be distinguished by peptide map and quantitative complement fixation techniques with relatedness estimates of >95%. Amino terminal sequence analysis showed variability at position 4 for several p30's with complete homology otherwise through 24 residues. The intrastrain heterogeneity in p30 isoelectric points could not be explained by common contaminants, as shown by peptide mapping, and is more likely based on post-transcriptional modifications. These data provide a chemical basis for the recently described type-specific immunological properties of individual p30's.

Amino Acid Sequence↗