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51Cr release cytotoxicity radioimmunoassay to detect immune cytotoxic reactions to rat Schwann cells in vitro.

Monolayers of rat Schwann cells incubated with 51Cr were used as targets for a cytotoxicity assay employing rabbit antiserum to galactocerebroside (R anti-GalC). Specific 51Cr release was demonstrated which was heat sensitive and complement-dependent. The assay was readily performed, reproducible and quantitative, and should prove useful in assessing anti-Schwann cell cytotoxic activity of experimental and human serum.

Animals↗

Comparison of histones in normal and xeroderma pigmentosum lymphoblastoid cells.

Histones from normal human and xeroderma pigmentosum, complementation group A (XPA), lymphoblastoid cells were compared both quantitatively, qualitatively and for binding affinity for DNA. Electrophoretic examination of the histones showed that all five major histone species were present in both cell groups and that there were no quantitative differences between normal and XPA histones. Binding affinity to [3H] mammalian DNA of the histones was determined. No significant differences were observed in binding of either normal or XPA histones to DNA.

Animals↗

Total salivary IgA, serum C3c and IgA in obese school children.

Studies of the immunologic function in adult obese humans and experimental models indicate that excess adiposity is associated with impairments in host defense mechanisms. The aim of this work was to analyze the secretory and humoral immune system in obese children (n = 105, 55 boys, 50 girls ), between 6 and 13 years of age. Samples of non-stimulated saliva and whole blood were collected from fasting patients. Total salivary IgA (IgAsal), serum C3 complement (C3c) and Immunoglobulin A (IgA) were determined by quantitative radial immunodifussion on agar gel layers ( Diffu-plate, Biocienti;fica SA ). Results, expressed as mg/dl, were compared to laboratory reference values from healthy children of either sex in the same range of age that belong to the same socioeconomic class (n = 60). Data (Mean +/- 1 SD) of the whole population were: IgAsal: 11.4 +/- 4.8 vs 14.8 +/- 6.9; C3c: 190.7 +/- 53.1 vs 126.3 +/- 45.5; IgA: 194.5 +/- 101.5 vs 157.2 +/- 19.9. Data distribution showed higher frecuencies near the zone of the highest reference values for serum C3c; when results of IgA and IgAsal were expressed as percentage of the mean reference value, 51% and 48.6% of the whole studied population presented data lower than 100% and 75% respectively. These results show a compromised secretory immune system without incidence of clinical symptoms and infections, whereas humoral immunity might not be profoundly affected.

Journal Article↗

A set of three genes regulates photoperiodic responses of flowering in rice (Oryza sativa).

Differentiation in photoperiodic response of flowering has been key to the evolution and wide geographic distribution of rice, an essentially short-day plant. Crosses were made such that the hybrid F1 plants flower later than the late-flowering parents to investigate the genetic basis underlying this differentiation. From initial experiments, three major genes for flowering time were identified from four naturally occurring variants under natural long-day conditions. An F2-derived trigenic mutant line bred-true for a day-neutral response was selected and used as the recipient to synchronize the genetic background for the major genes. Experiments conducted under various daylengths indicated that these genes are responsible for photoperiodic sensitivity and the trihybrid has a critical daylength between 13.5 and 14 h. The three genes regulate photoperiodic responses qualitatively and quantitatively through complementary and other epistatic effects, respectively. The complementation suggests that the three genes act in a linear manner to repress the transition from the vegetative to reproductive phases under long daylengths. This set of genes also provides a model to understand the genetic mechanism underlying the elongated vegetative growth period in the F1 generation, which is usually an obstacle to the use of heterosis, and the selection for early maturation in rice breeding.

Crosses, Genetic↗

Regional heterogeneity in immunoreactive macrophages/microglia in the rat pineal gland.

Using specific macrophage antibodies (OX-42, OX-6, ED-1 and ED-2), this study examined the distribution of macrophages/microglia in the pineal gland of adult rats. Except for ED-2, all antibodies labeled distinct subpopulations of macrophages/microglia in the gland; ED-2 labeling was hardly detectable. The quantitative study showed that the pineal macrophages/microglia (PMM) expressing complement type 3 receptors (OX-42) were more numerous than those expressing the major histocompatibility complex class II antigen (OX-6) or unknown cytoplasmic/lysosomal antigens (ED-1). The PMM were ubiquitous, especially the OX-42 labeled cells which were distributed from the dorsal to the ventral aspect of the gland. The macrophages/microglia labeled with OX-6 or ED-1 were localized mainly in the intermediate portion of the pineal gland. Immunolabeled cells were sparsely distributed in the distal portion of the pineal gland. A notable feature was that the OX-6 labeled macrophages/microglia showed a proximal-distal gradient in cell density. Another interesting feature was the occurrence of prominent cell aggregations around the larger blood vessels. These cells were mostly round and exhibited different immunoreactivity. Confocal microscopic study with triple immunolabeling further revealed that individual PMM cell possessed two or more different antigens (ED-1+/OX-6+, OX-42+/OX-6+ or OX-42+/ED-1+). Remarkably, a large population co-expressed ED-1+/OX-6+/OX-42+. The present results show that the expression of immunoreactive molecules in PMM varies in topographical distribution of the cells. It is suggested that this may be linked to their immunoregulatory functions in the gland.

Animals↗

Isolation and immunological characterization of a major surface glycoprotein (gp54) preferentially expressed on certain human B cells.

A major membrane glycoprotein with mol wt of approximately 54,000 has been isolated from membrane preparations of B-type lymphoid cell lines. Antiserum prepared against the isolated material specifically precipitated this glycoprotein from membranes labeled by surface radioiodination or by metabolic labeling. This antiserum was shown by complement-mediated cytotoxicity assay, membrane immunofluorescent staining, and by quantitative absorption analysis to react preferentially with certain B-lymphoblastoid cell lines, with a minor population of peripheral blood B lymphocytes, and a major population of tonsillar B lymphocytes. Certain B-cell leukemias also expressed the antigen, whereas others did not. Considerable variability was observed among positive B cells in the intensity of fluorescent staining even among the leukemic cells from a single individual. Although T cells, including T cells, were negative by direct immunofluorescent and cytotoxicity assay, evidence for low levels of the antigen on the cells of T cell lines was obtained. The whole specific antiserum and its F(ab')2 fragments stimulated B lymphocytes to proliferate. This proliferation did not produce differentiation to plasma cells and was T-cell independent. The monovalent Fab fragments had no effect. None of these preparations timulated T cells. The possibility that this antigen, termed gp54, may play some role in B-cell activation is discussed.

Antigens, Surface↗

Stimulated raman scattering of rapidly amplified short laser pulses.

The theory of transient forward stimulated Raman scattering (FSRS) of rapidly amplified short laser pulses is put forth to complement the classical theory for FSRS of stationary pulses. Quantitative conditions for FSRS suppression are identified. In particular, it is shown quantitatively how the limitation imposed by pumped pulse FSRS on the output laser intensity in plasma-based ultrapowerful backward Raman amplifiers can be overcome through a selective detuning of the Stokes resonance.

Journal Article↗

A systematic study of neutrophil degranulation and respiratory burst in vitro by defined immune complexes.

Defined immune complexes (IC) were used to compare the effect of antibodies of different classes and subclasses on neutrophil respiratory burst and degranulation. IC were made from 5-iodo-4-hydroxy-3-nitrophenacetyl (NIP) conjugated to bovine serum albumin (BSA) and chimaeric mouse-human anti-NIP monoclonal antibodies including IgA2, IgE and all four IgG subclasses. The activation of neutrophils by IC depended on antibody class and subclass, on antigen epitope density, on antigen: antibody ratio and on the medium used. The ability to generate the respiratory burst showed a different pattern to the ability to give rise to degranulation. Compared with other IC, IgA2 IC provided the strongest stimulus for neutrophil activation. IgG1 IC, IgG2 IC and IgG4 IC activated neutrophils moderately or weakly IgG3 IC were unable to stimulate the respiratory burst, but could cause strong degranulation. IgE IC could hardly cause any neutrophil response. Neutrophil degranulation in response to IgG3 IC in serum-free medium or heat-inactivated serum was fast, and it quickly reached maximum. Degranulation caused by IgA IC was relatively slow, but gradually increased during incubation. The activity of IgG1 IC, IgG2 IC and IgG4 IC generated a respiratory burst increased with antibody excess and decreased with antigen excess. The activity of IgA2 IC, however, was not affected by change of antigen and antibody ratio. A specific role of serum, possibly due to complement, was found in enhancing degranulation, both temporally and quantitatively, by IgA2 IC.

Animals↗

Antibodies against nuclear components in schistosomiasis. Results compared to values in patients with rheumatoid arthritis, systemic lupus erythematosus, and osteoarthrosis.

Occurrence of autoantibodies against nuclear material was compared in groups of patients with rheumatoid arthritis (RA n = 22), systemic lupus erythematosus (SLE n = 24), osteoarthrosis (OA n = 25), and chronic schistosomiasis mansoni (CSM n = 28). Anti-ds DNA antibody was detected by an ammonium sulphate precipitation radioimmunoassay antibodies against extractable nuclear antigen (ENA) were detected and differentiated in RNAse-resistant and RNAse-sensitive components (Sm and RNP antigens) with an ELISA technique. IgG organ-non-specific and granulocyte-specific antinuclear antibodies (ANA) were detected by immunofluorescence technique with quantitative titration of positive reactions and determination of complement-fixing properties. The results in groups of patients with SLE, RA and OA were of confirmative nature and supported that the different methods detect different systems of autoantibodies and nuclear autoantigens. In CSM it was demonstrated that 23 of 28 cases had positive reactions to the RNAse-resistant part of ENA (the Sm-antigen), a significant difference from the three other groups of patients (P less than 0.001). The antibody was in all cases of IgM class, in seven cases also of IgA class. Antibodies against nuclear material in CSM are probably a consequence of heavy disturbance of the immune system in this chronic infection with great permanent antigen load. It is a matter of discussion, whether production of these antibodies is induced by nuclear material from the host or from the parasite.

Adolescent↗

Immunologic aspects of human endometriosis.

General and specific immune function were examined in women with endometriosis. Nonspecific parameters included total leukocyte and differential counts, quantitative immunoglobulin (IgG, IgA, and IgM) determinations, total hemolytic complement, C3, C4, mitogen-induced lymphocyte stimulation, and human leukocyte antigen (HLA) typing; no differences were observed when data were compared to age-matched controls without endometriosis. In contrast, the specific immune response T-lymphocyte-mediated cytotoxicity to autologous endometrial cells was significantly reduced (P less than 0.01) in women with endometriosis. When results from patients were analyzed according to clinical severity of endometriosis, even more striking immunologic alterations were delineated. In addition, lymphocyte stimulation responses to autologous endometrial antigen were lower in patients with severe or moderate disease, approaching statistical significance (P = 0.18 and 0.12, respectively). These studies suggest an immunologic basis for development of endometriosis.

Adult↗

Spatio-temporal analysis of irregular vocal fold oscillations: biphonation due to desynchronization of spatial modes.

This report is on direct observation and modal analysis of irregular spatio-temporal vibration patterns of vocal fold pathologies in vivo. The observed oscillation patterns are described quantitatively with multiline kymograms, spectral analysis, and spatio-temporal plots. The complex spatio-temporal vibration patterns are decomposed by empirical orthogonal functions into independent vibratory modes. It is shown quantitatively that biphonation can be induced either by left-right asymmetry or by desynchronized anterior-posterior vibratory modes, and the term "AP (anterior-posterior) biphonation" is introduced. The presented phonation examples show that for normal phonation the first two modes sufficiently explain the glottal dynamics. The spatio-temporal oscillation pattern associated with biphonation due to left-right asymmetry can be explained by the first three modes. Higher-order modes are required to describe the pattern for biphonation induced by anterior-posterior vibrations. Spatial irregularity is quantified by an entropy measure, which is significantly higher for irregular phonation than for normal phonation. Two asymmetry measures are introduced: the left-right asymmetry and the anterior-posterior asymmetry, as the ratios of the fundamental frequencies of left and right vocal fold and of anterior-posterior modes, respectively. These quantities clearly differentiate between left-right biphonation and anterior-posterior biphonation. This paper proposes methods to analyze quantitatively irregular vocal fold contour patterns in vivo and complements previous findings of desynchronization of vibration modes in computer modes and in in vitro experiments.

Adult↗

Kinetic analysis of the amplification phase for activation and binding of C3 to encapsulated and nonencapsulated Cryptococcus neoformans.

Encapsulated and nonencapsulated cryptococci exhibit quantitative and qualitative differences in their activation of the complement system. We examined the kinetics for the rapid amplification phase in which C3 was activated and bound to encapsulated cryptococci, nonencapsulated cryptococci, and zymosan particles. Yeast cells were incubated in normal human serum containing 125I-labeled C3, and bound C3 fragments were measured after 1 to 64 min of incubation. A kinetic analysis showed that the apparent first-order rate constant (k') for binding of C3 to nonencapsulated cryptococci did not differ significantly from k' for binding of C3 to zymosan particles (P greater than 0.05). However, the rate constant for binding of C3 to encapsulated cryptococci was significantly (P less than 0.001) greater than k' for binding of C3 to nonencapsulated cryptococci and zymosan particles. A plot of C3 molecules bound to encapsulated cryptococci versus time cubed was nearly linear, suggesting that accumulation of C3 in the cryptococcal capsule follows the kinetics predicted by an expanding sphere. In contrast, the plot of C3 molecules bound to nonencapsulated cryptococci or zymosan particles against time was nearly linear, but those plots against time squared or time cubed were not. This result indicates that the rate-limiting step for the addition of C3 fragments to these latter yeast cells follows the kinetics of neither the perimeter of an expanding circle nor the surface of an expanding sphere. Taken together, the results indicate that the high rate of accumulation of C3 in the cryptococcal capsule is consistent with the expected geometry of an expanding sphere of bound C3 within the three-dimensional matrix of the capsule.

Complement Activation↗

Health effects of passive smoking. 6. Parental smoking and childhood asthma: longitudinal and case-control studies.

BACKGROUND: The relation of parental smoking to wheezing and asthma occurring after the first year of life was assessed by a systematic quantitative review of case-control and longitudinal studies, complementing earlier reviews of cross sectional surveys and wheezing in early childhood. METHODS: Fifty one relevant publications were identified after consideration of 1593 abstracts selected by electronic search of the Embase and Medline databases using keywords relevant to passive smoking in children. The search was completed in April 1997 and identified six studies of asthma incidence, seven of prognosis, 22 case-control studies, and 10 case series addressing disease severity. RESULTS: Maternal smoking was associated with an increased incidence of wheezing illness up to age 6 (pooled odds ratio 1.31, 95% CI 1.22 to 1.41), but less strongly thereafter (1.13, 95% CI 1.04 to 1.22). The long term prognosis of early wheezing illness was better if the mother smoked. The pooled odds ratio for asthma prevalence from 14 case-control studies was 1.37 (95% CI 1.15 to 1.64) if either parent smoked. Four studies suggest that parental smoking is more strongly associated with wheezing among non-atopic children. Indicators of disease severity including symptom scores, attack frequency, medication use, hospital attendance, and life threatening bronchospasm were in general positively related to household smoke exposure. CONCLUSIONS: The excess incidence of wheezing in smoking households appears to be largely non-atopic "wheezy bronchitis" with a relatively benign prognosis, but among children with established asthma, parental smoking is associated with more severe disease. This apparent paradox may be reconciled if environmental tobacco smoke is considered a co-factor provoking wheezing attacks, rather than a cause of the underlying asthmatic tendency.

Asthma↗

Spatial analysis of the neuronal density of aminergic brainstem nuclei in primary neurodegenerative and vascular dementia: a comparative immunocytochemical and quantitative study using a graph method.

A graph method was employed to analyse spatial neuronal patterns of pontine nuclei with ascending aminergic projections to the forebrain (nucleus centralis superior (NCS), raphes dorsalis (NRD) and locus coeruleus (LC)), in Alzheimer disease (AD), Huntington disease (HD), and vascular (VD) as well as "mixed-type" (VA) dementia, compared with non-demented controls (CO) and a small sample of brains from schizophrenics ("dementia praecox" (DP)). The quantitative evaluations by the "minimal spanning tree (MST)" were complemented by rough neurofibrillary tangle (NFT) counts and by semiquantitative immunohistochemical assessment of amyloid deposition, neuritic plaque formation, and cellular gliosis. The AD cases showed a significant decline of neuronal density in all nuclei examined, as compared with controls and DP. Neuronal loss was not significant in VD, while the mixed cases with both vascular and Alzheimer-type pathology exhibited pronounced changes of neuronal density. Amyloid deposition occurred almost exclusively in AD and VA, as a rule, being of moderate degree, except for two presenile AD cases where it was marked. NFT were significantly increased in all nuclei in AD and in the VA cases, while they only occasionally appeared beyond age 55 in HD, DP and CO. The four HD cases showed in the NCS and NRD neuronal loss as severe as in AD. This neuronal loss implicates impairment of serotoninergic and noradrenergic neuromodulation as one basic mechanism promoting dementia in AD, VA and perhaps in HD.

Adult↗

"Structural factor" in primary and secondary hypertension.

The history of research on the "structural factor" in primary hypertension is briefly reviewed, and the gradual realization of its important influence on the hemodynamics of hypertension is outlined, as seen from a "personal angle." Experiences from previous studies of normal vascular function in animals were decisive for our first hemodynamic demonstration concerning the "structural upward resetting" of the systemic resistance vessels in human primary hypertension. Subsequent quantitative studies in rats with primary and secondary hypertension complemented these studies, confirming that the critical structural changes are a rapid increase in precapillary resistance at full dilatation associated with an increase in wall/lumen ratio due mainly to media hypertrophy and occurring in both primary and renal hypertension. Analyses were also performed concerning cardiac, barostat, and venous structural resettings, which are briefly mentioned. In our first studies of human primary hypertension, we suggested that the structural factor might itself be genetically reinforced, and increasing evidence in favor of this view is now accumulating. It is further discussed how antihypertensive therapy should be directed primarily against the structural upward resetting, as dependent on the local pressure and "trophic" influences, and some of our results in rat models are outlined. Finally, as the structural factor at the systemic resistance level also invites positive feedback interactions with functional "pressor" influences, it is, in a way, more difficult to explain why 85-90% of people remain normotensive than how hypertension gradually develops in 10-15% of people. This points to some powerful and durable negative feedbacks, which are still poorly understood, because most so far known barostats are readily reset upward in hypertension. It is here that the Muirhead renomedullary depressor system, and perhaps also the unmyelinated baroreceptor-volume receptor afferents, may be of particular importance.

Adaptation, Physiological↗

Effect of antibiotics on the formation of specific antibodies.

Immune response to staphylococcal haemolysin and Haemophilus influenzae capsular antigen administered simultaneously with antibiotics was studied in rabbits. In addition to specific humoral antibodies, the quantitative values of IgG, IgA, IgM and C'3 complement were determined. Statistically significant deficiency of immune response was observed in all cases in animals which were given the antigen with the antibiotic in comparison with the controls which were immunized by the antigen alone. Statistically significant differences were also observed in the levels of immunoglobulins (mainly IgG and IgM) in animals which were given antigens simultaneously with antibiotics in comparison with animals which were given antibiotics alone.

Animals↗

Fucose-activated killer (FAK) cells: anomalous killers with augmented cytotoxic activity.

The effects of monosaccharides on various lymphocyte functions have provided useful probes for the study of cell-cell interactions. In this report, we show that a monosaccharide, alpha-L-fucose, significantly enhances the cytolytic capacity of MLC-induced or preincubated effector cells. The increase in activity was seen against cytotoxic T lymphocyte (CTL) targets (:relevant PHA blasts), natural killer cell (NK) targets (:K562), and natural cytotoxic cell (NC) targets (:MA-160). In addition, traditionally NK-insensitive targets (Raji cells, irrelevant and autologous PHA blasts) were lysed after preincubation of effector cells with fucose. Conversely, ADCC activity was not significantly increased with fucose induction. The addition of fucose directly to assay cultures did not enhance NK or CTL activity, whereas other sugars, such as alpha-methyl-D-mannoside and D-fructose, were inhibitory. The proportion of target-binding cells was not affected by preincubation with fucose, but the percentage of lytic conjugates was doubled. Significant augmentation of NK activity could be observed within 24 hr of incubation with alpha-L-fucose. Conversely, when fucose was added more than 24 hr after initiation of the culture, the increase in cytolytic activity was not observed. Parallel to the increase in cytolytic activity, after preincubation with alpha-L-fucose, an increase in the expression of a newly defined human NC cell marker, HNC-1A3, was observed. The HNC-1A3+ cells were not the major subpopulation responsible for fucose-induced activity, as ascertained by the use of positively sorted cells. The populations expressing antigens defined by the antibodies OKT8 and Leu-7 showed no quantitative change. The treatment of cells with OKM1 and complement (C) before culture eliminated fucose-enhanced killing, whereas similar treatment with OKT8 and C had no significant effect. The induction of fucose-activated killers (FAK) does not result in higher concentrations of interferon (IFN) in culture supernatants, in contrast to poly I:C, which induced both higher cytolytic activity and high titers of IFN. In addition, the induction of FAK was not sensitive to 100 ng/ml of cyclosporin A, suggesting that IL 2 did not play a major role in fucose activation of killing. These results provide strong evidence that alpha-L-fucose is capable of augmenting nonspecific activity by acting on OKM1+ precursors of cytotoxic cells and influencing a postbinding event.

Cytotoxicity Tests, Immunologic↗

French angles: a simple aid to neurodevelopmental examination.

"French angles" are the amplitude of passive movement at a single joint, which can be easily measured using a goniometer, and reflect the lengthening capacity of muscles--a component of passive tone. Fifty infants aged 1-52 weeks had their "French angles" measured by non-expert examiners using a plastic goniometer. All the angles measured, except ankle dorsiflexion, increased in a predictable, linear fashion from birth to one year of age. Thus in normal term infants passive tone gradually relaxes from birth to the age of one year. Three additional infants with known neuromuscular disorders were found to have angles outside the obtained normal range. The babies with cerebral palsy had reduced adductor angles reflecting adductor spasm, and the baby with Werdnig Hoffman syndrome had an increased adductor angle reflecting increased adductor extensibility. The results provide a quantitative measurement of neurological maturation during infancy, and should complement the routine neurodevelopmental assessment. The method proved quick, simple and reliable, and may become useful as a screening test for neuromuscular disorders.

Biomechanical Phenomena↗