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Results for “quantitative complementation”

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PubMed1955

The antigenic similarity of human low density lipoproteins.

THE FOLLOWING HUMAN LOW DENSITY LIPOPROTEINS WERE PREPARED: beta-lipoproteins of densities greater than 1.040 (A, B,C) a beta-lipoprotein of -S(1.063) = 5 (D), a lipoprotein of -S(1.063) = 19 (E), and a lipoprotein of -S(1.063) = 70 (F). Data are presented which show the immunochemical homogeneity of the D lipoprotein rabbit-anti-D lipoprotein system. Cross-reactions between antibody to A and D lipoproteins and the above lipoproteins have been demonstrated by quantitative precipitation, quanitative complement fixation, and single and double diffusion in agar. The antigenic similarities appear to be associated with the protein portions of the molecule. The antisera produced did not differentiate the low density lipoprotein classes.

Animals↗
PubMed1958

Characterization of a factor formed in the course of adenovirus infection of tissue cultures causing detachment of cells from glass.

Infectious tissue culture fluids of the majority of serotypes of adenovirus at low dilutions detach HeLa or KB cells from glass surfaces within a few hours after inoculation. A reproducible method for testing cell detachment was devised. The factor present in infectious tissue culture fluids and responsible for cell detachment is trypsin-sensitive and non-dialyzable; it is smaller and more resistant to the effect of heat or ultraviolet light than the infectious virus particle. Cell detachment activity was found to be temperature-dependent, and the cell-detaching titer of infectious tissue culture fluids was not affected by repeated exposure to HeLa cells. Inhibition of cell detachment by human or rabbit sera was observed only when other antibodies to adenovirus antigens were also present, but the antibody inhibiting cell detachment could not be correlated quantitatively with complement-fixing or homologous neutralizing antibody.

Adenoviridae↗
PubMed1969

Immunologic studies of water-soluble human amyloid fibrils. Comparative studies of eight amyloid preparations.

Eight preparations of soluble amyloid and degraded amyloid (DAM) were compared immunologically. Unlike amyloid fibrils, six of eight preparations of DAM proved to be relatively strong immunogens. Antisera to DAM reacted weakly or not at all with normal human serum or extracts of normal tissues, but were specifically reactive with amyloid fibrils or DAM. Comparative studies of DAM'S from eight different subjects showed some degree of cross-reactivity among them, yet demonstrated that they were not identical. Similar conclusions were obtained by quantitative precipitin and complement fixation analyses. Comparison of the amyloid fibrils with the homologous DAM by complement fixation and absorption studies demonstrated the existence in DAM of antigenic determinants that were lacking or inaccessible in the native fibrils. A search for amyloid precursors and antibodies to amyloid in the sera of 12 patients proved unsuccessful.

Amyloid↗
PubMed1996

Genetic interactions between naturally occurring alleles at quantitative trait loci and mutant alleles at candidate loci affecting bristle number in Drosophila melanogaster.

Previously, we mapped quantitative trait loci (QTL) affecting response to short-term selection for abdominal bristle number to seven suggestive regions that contain loci involved in bristle development and/or that have adult bristle number mutant phenotypes, and are thus candidates for bristle number QTL in natural populations. To test the hypothesis that the factors contributing to selection response genetically interact with these candidate loci, high and low chromosomes from selection lines were crossed to chromosomes containing wild-type or mutant alleles at the candidate loci, and the numbers of bristles were recorded in trans heterozygotes. Quantitative failure to complement, detected as a significant selection line*cross effect by analysis of variance, can be interpreted as evidence for allelism or epistasis between the factors on selected chromosomes and the candidate loci. Mutations at some candidate loci (bb, emc, h, Dl, Hairless) showed strong interactions with selected chromosomes, whereas others interacted weakly (ASC, abd, Scr) or not at all (N, mab, E(spl)). These results support the hypothesis that some candidate loci, initially identified through mutations of large effect on bristle number, either harbor or are close members in the same genetic pathway as variants that contribute to standing variation in bristle number.

Alleles↗
PubMed1999

Q methodology, risk training and quality management.

The results of a Q methodological study of professional understandings of the notion of risk in mental health services within the UK are discussed in relation to the relevance for staff training and quality assurance. The study attempted to access the diversity of understandings of risk issues amongst a multi-professional group of staff (n = 60) attending inter-agency risk training workshops in 1998. Q methodology is presented as both an appropriate means for such inquiry and as a novel experiential technique for training purposes. A tentative argument is advanced that the qualitative accounts generated by Q research could assist in systematic reviews of quality, complementing the singularly quantitative approaches typically represented in the audit process.

Attitude of Health Personnel↗
PubMed1989

Participant observation and its place in the study of illicit drug abuse.

Participant observation has long been utilized as a valuable research methodology in the study of illicit drug abuse. It should not be viewed in isolation, but seen as an essential complement to the quantitative analysis of trends in drug use, such as epidemiological studies and the monitoring of services for drug users. Fieldwork conducted at the Drug Indicators Project and other relevant studies highlight the practical and ethical problems faced by the participant observer, including issues of access, co-operation and confidentiality. This is particularly pertinent when working with drug users not in contact with services. When working with drug users in a treatment context, the need to be flexible and sensitive to the needs of agency staff is stressed, and the ways in which participant observers can operate as volunteers are explored. Contemporary concern about HIV infection, AIDS, and risk behaviour amongst drug users, raises the potential for an expansion and redefinition of the role of the participant observer to take on some of the functions of health educator, and two options are suggested.

Humans↗
PubMed1983

The use of solid medium to study effects of cadmium, copper and zinc on yeasts and yeast-like fungi: applicability and limitations.

A defined solid medium has been used to examine the responses of Aureobasidium pullulans, Saccharomyces cerevisiae and Sporobolomyces roseus to cadmium, copper and zinc. Experiments where aliquot volumes of metal salt solutions were added to wells in the centre of agar plates revealed marked differences between these organisms. The yeast-like fungus A. pullulans was the least sensitive but S. cerevisiae was more sensitive to cadmium than zinc: the reverse was true for S. roseus. Quantitative data, which complemented the qualitative results, were obtained by measurement of metal concentrations in the plates.

Cadmium↗
PubMed1994

An evaluation of nurse-led team care within a rehabilitation ward for elderly people.

This small exploratory study evaluated the effects of introducing a system of nurse-led team care on a ward providing intensive nursing and rehabilitation to elderly people. A quasi-experimental design compared three variables between the study ward and two similar wards within the unit. These were: quality of care, job satisfaction, length of patient stay. Quantitative data were complemented by semi-structured interviews with team members and by observation of team meetings. Quality of care scores showed an improvement on the study ward, but no difference on the main comparison ward. There were no differences between nurse job satisfaction between the study and comparison wards or in length of patient stay throughout the period of evaluation. Observation of team meetings suggested that communication was more structured and focused on the study ward and that patient goals were more clearly specified. Interviews suggested three main factors in successful implementation of the change to nurse-led team care: commitment of the team, open communication about difficulties, the support of managers and medical staff. The main effects noted were: partnership with patients, equality between team members, improved decision making and quality of care. Further studies of nurse-led team care are required, and the stress and anxiety for staff consequent on developing the nurse's role in this way should be considered.

Aged↗
PubMed1983

Studies on subcellular fractions which are involved in myelin membrane assembly: isolation from developing mouse brain and characterization by enzyme markers, electron microscopy, and electrophoresis.

An extensive scheme for the subcellular fractionation of myelinating mouse brain is presented. Several centrifugation procedures for the separation of membranes involved in myelinogenesis are critically appraised, and guidelines for selection of centrifugation conditions are given. Characteristics of subcellular fractions are presented in the form of electron micrographs; also presented are distribution of RNA and protein; electrophoretic profiles of membrane proteins, and verification of the myelin-specific basic proteins, proteolipid protein, and glycoprotein by the immuno-electroblot technique; and the distribution of eight marker enzyme activities. Myelin-related membranes were found to differ both qualitatively and quantitatively in their complement of myelin-specific proteins. These myelin-containing fractions appear to represent different stages of myelination that coexist in developing mouse brain. These results provide the fundamental methodologies and background information for kinetic radioisotope analysis of intracellular events in the assembly of myelin presented in a companion article.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗
PubMed1967

Immunological time scale for hominid evolution.

Several workers have observed that there is an extremely close immunological resemblance between the serum albumins of apes and man. Our studies with the quantitative micro-complement fixation method confirm this observation. To explain the closeness of the resemblance, previous workers suggested that there has been a slowing down of albumin evolution since the time of divergence of apes and man. Recent evidence, however, indicates that the albumin molecule has evolved at a steady rate. Hence, we suggest that apes and man have a more recent common ancestry than is usually supposed. Our calculations lead to the suggestion that, if man and Old World monkeys last shared a common ancestor 30 million years ago, then man and African apes shared a common ancestor 5 million years ago, that is, in the Pliocene era.

Animals↗
PubMed1972

Enzyme evolution in the Enterobacteriaceae.

An immunological approach has been used for the study of alkaline phosphatase evolution in bacteria of the family Enterobacteriaceae. Antisera were prepared against alkaline phosphatase from Escherichia coli and Klebsiella aerogenes and tested against the unpurified alkaline phosphatases of 32 strains of enterobacteria by double diffusion and quantitative micro-complement fixation. The immunological relationships detected among the alkaline phosphatases of enterobacteria agree approximately with those reported for five other enzymes, as well as with the tryptic peptide pattern similarities found for two other enzymes, and with the relationships detected by interspecific deoxyribonucleic acid hybridization tests.

Alkaline Phosphatase↗
PubMed1968

Immunological studies on dermatophytes. 3. Further analyses of the reactivities of neutral polysaccharides with rabbit antisera to Microsporum quinckeanum, Trichophyton schoenleinii, Trichophyton rubrum, Trichophyton interdigitale, and Trichophyton granulosum.

The serological reactivities of polysaccharides isolated from five species of dermatophytes, Microsporum quinckeanum, Trichophyton granulosum, T. interdigitale, T. rubrum, and T. schoenleinii, with rabbit antisera to these species were studied qualitatively by precipitation in gel and quantitatively by complement-fixation analyses. Significant differences in the serological reactivities of the galactomannans I were detected with antisera to T. schoenleinii and T. interdigitale. The differences appeared to be related to the specificity of these antisera for the galactofuranose residues in the polysaccharides. Antisera to M. quinckeanum, T. granulosum, or T. rubrum did not detect differences between the galactomannans I. The serological reactivities of the galactomannans II were different with each of the five antisera. The reactivities of the glucans could be correlated with the amount of alpha 1 --> 6 linked glucopyranose residues when antisera to T. schoenleinii and M. quinckeanum were used.

Animals↗
PubMed1999

The design and effectiveness of therapeutic community research in Europe: an overview.

An overview of the state of the art of research on the treatment services of the therapeutic community for drug addicts in Europe is presented. This research tradition has largely been fragmented and local in its implementation. There has been a scientific gap concerning evaluation research and the treatment services offered by the therapeutic community. The American research antecedents to the European tradition are reviewed. The essential European groups, research designs and results are presented for each country with something greater than an ad hoc study experience. The strengths and weaknesses of the research designs, results and organizations are critically assessed. Recommendations for future research are presented and referenced to specific recommendations for therapeutic community research coming out of an American National Institute on Drug Abuse Technical Review. Among the conclusions of the overview is the need for more qualitative phenomenological research to complement the existing quantitative approach.

Community Mental Health Services↗
PubMed1977

E and EAC rosettes in man and nonhuman primates and the effect of thymosin in vitro.

E (erythrocyte) and EAC (erythrocytes coated with antibody and complement) rosettes were quantitated in baboons, cebus monkeys and cotton-topped marmosets. There was poor correlation between E rosette levels and other parameter of T-lymphocyte function. In nonhuman primates, E rosettes were increased in the presence of thymosin fraction V, while human E rosettes were not affected.

Animals↗
PubMed1999

Differential expression of connexin43 and desmin defines two subpopulations of medial smooth muscle cells in the human internal mammary artery.

Upregulation of connexin43-gap junctions is associated with transition of contractile vascular smooth muscle cells (SMCs) to the synthetic state. To determine whether phenotypically distinct subpopulations of medial SMCs differentially express connexin43, we investigated the human distal internal mammary artery, a structurally heterogeneous vessel with features ranging from elastic to elastomuscular to muscular. Immunoconfocal microscopy combined with quantitative analysis and complemented by in situ hybridization showed that SMCs in the elastic medial regions expressed high levels of connexin43 but low levels of desmin, whereas those of muscular medial regions expressed low levels of connexin43 but high levels of desmin. Ultrastructurally, SMCs of both regions were of the contractile phenotype, but the former cells were irregular in shape with relatively prominent synthetic organelles whereas the latter were spindle shaped with fewer synthetic organelles. Vimentin, smooth muscle alpha-actin, calponin, h-caldesmon, and myosin heavy chains (SM1 and SM2) were equally highly expressed by most cells in both subpopulations. The connexin43/desmin expression pattern of SMCs in regions of intimal thickening resembled those of elastic medial regions. These findings refine the view suggested from previous studies that high levels of connexin43 expression are associated with SMCs of a less contractile/more synthetic phenotype. In the internal mammary artery, the 2 subpopulations of SMCs with markedly different connexin43 expression levels both represent a differentiated contractile phenotype, but the subpopulation showing high levels of connexin43-gap junctions is characterized by low levels of desmin and structural features that reflect a more synthetic tendency.

Aged↗
PubMedDate not supplied

Visualization of airflows in push-pull ventilation systems applied to surface treatment tanks.

A pilot installation was designed that simulates a surface treatment tank fitted with a push-pull ventilation system. The installation contained elements for measuring and controlling the operational variables (flow rate and tank temperature) and smoke generating equipment for injecting smoke through the holes of the push unit and from the tank surface. Visual observation and video recording of the flows involved meant it was possible to follow the qualitative behavior of the push flow rate along the tank surface and to identify any emissions not captured by the exhaust system. It was possible to differentiate the initial semifree push curtain, its impact with the tank surface, the wall jet that moved toward the exhaust, and its entrance into the exhaust. The methodology proposed is complemented by a quantitative technique for measuring the efficiency, using sulfur hexafluoride as tracer, which permits the causes and location of losses in the ventilation system to be determined.

Air Movements↗
PubMed1984

Ontogeny of the immune system: fetal lamb as a model.

We examined adult sheep lymphocytes for the following surface markers: Surface membrane immunoglobulin, antigen identified by anti-sheep thymocyte globulin and complement receptors. We quantitated sheep peripheral blood mononuclear leukocyte proliferative responses to mitogens and alloantigens, and demonstrated a neutrophil-directed chemotactic factor (N-LDCF) liberated by mitogen-stimulated sheep mononuclear cells. A comparison of adult and fetal sheep from 120-150 d of gestation demonstrated that 1) fetal sheep had adult proportions of surface membrane Ig+ and T+ lymphocytes but a significant decrease in FcIgG receptor+ lymphocytes, 2) proliferative responses of fetal sheep blood mononuclear cells to mitogens and alloantigens were comparable to adult responses, and 3) fetal mononuclear leukocytes failed to produce the lymphokine, N-LDCF, in response to mitogen stimulation.

Age Factors↗
PubMed2005

The role of neural synchronization in the emergence of cognition across the wake-sleep cycle.

Searching for the neural code underlying consciousness and cognition is one of the most important activities in contemporary neuroscience. Research with neuronal oscillations at the level of single-neuron, local cell assemblies, and network system have provided invaluable insights into different mechanisms of synaptic interactions involved in the emergence of cognitive acts. A cognitive neuroscience of conscious experience is gradually emerging from behavioral and neuroimaging studies, which can be successfully complemented with the quantitative EEG findings discussed here. This review is an attempt to highlight the value of state-dependent changes in human neurophysiology for a better understanding of the neurobiological substrate underlying those aspects of cognition drastically affected by sleep states. Recent advances related to synchronization mechanisms potentially involved in brain integration processes are discussed, emphasizing the value of scalp and intracranial EEG recordings at determining local and large-scale dynamics in the human brain. Evidence supporting the critical role of state-dependent synchrony in brain integration comes mainly from studies on the theta and gamma oscillations across the wake-sleep continuum, as revealed by human intracranial recordings. This review blends results from different levels of analysis with the firm conviction that state-dependent brain dynamics at different levels of neural integration can provide a deeper understanding of neurobiological correlates of consciousness and sleep functions.

Animals↗