931 resultados para ANTIBODIES ABSORPTION


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Although Porphyromonas gingivalis is a defined pathogen in periodontal disease, many subjects control the infection without experiencing loss of attachment. Differences in host susceptibility to the disease may be reflected in the pattern of humoral antibodies against specific P. gingivalis antigens. The aim of this study was to determine the presence of antibodies against immunodominant P. gingivalis antigens as well as the isotype and subclass of anti-P. gingivalis antibodies against outer membrane antigens in four groups of patients: P. gingivalis-positive, 1) with and 2) without periodontitis, and P. gingivalis-negative, 3) with and 4) without periodontitis. Antigens of molecular weight 92, 63, and 32 kDa and lipopolysaccharide were found to be immunodominant. Group 1 subjects showed a significantly higher response to the 92 and 63 kDa antigens compared with other groups. The response to lipopolysaccharide was significantly higher in group 1, and lower in group 4 than in groups 2, 3. Immunoglobulin G(1) (IgG(1)), IgG(2) and IgM antibodies against P. gingivalis outer membrane were present in all subjects, while only some subjects were seropositive for IgG(3), IgG(4) and IgA. There were no differences in concentrations for IgG(1), IgG(3) and IgM. The IgG(2) concentration in group 4 was significantly higher than in groups 1 and 2, while the IgG(4) concentration in group 4 was significantly lower than in other groups. The frequency of seropositivity for IgG(4) and IgA was lowest in group 4, while IgG; seropositivity was almost exclusively seen in healthy patients iii groups 2, 4. These findings suggest that the presence of IgG(3) may reflect non-susceptibility to the disease, while lack of IgG(4) may be indicative of periodontal health and lack of infection.

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Mouse monoclonal antibodies (mAbs) were raised against the major capsid protein, L1, of human papillomavirus type 16 (HPV16), produced in Escherichia coil with the expression plasmid pTrcL1. Epitope specificity could be assigned to 11 of these 12 antibodies using a series of linear peptides and fusion proteins from HPV16. One mAb (MC53) recognized a novel linear epitope that appears to be unique to the HPV16 genotype. A further 11 mAbs were characterized as recognizing novel and previously defined linear and conformational epitopes shared among more than one HPV genotype. The apparently genotype specific mAb could be useful for the development of diagnostic tests for vegetative virus infection in clinical specimens. (C) 1998 Academic Press.

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The Mellow and Autler-Townes probe absorption spectra of a three-level atom in a cascade configuration with the lower transition coherently driven and also coupled to a narrow bandwidth squeezed-vacuum field are studied. Analytical studies of the modifications caused by the finite squeezed-vacuum bandwidth to the spectra are made for the case when the Rabi frequency of the driving field is much larger than the natural linewidth. The squeezed vacuum center frequency and the driving laser frequency are assumed equal. We show that the spectral features depend on the bandwidth of a squeezed vacuum field and whether the sources of the squeezing field are degenerate (DPA) or nondegenerate (NDPA) parametric amplifiers. In a broadband or narrow bandwidth squeezed vacuum generated by a NDPA, the central component of the Mellow spectrum can be significantly narrower than that in the normal vacuum. When the source of the squeezed vacuum is a DPA, the central feature is insensitive to squeezing. The Rabi sidebands, however, can be significantly narrowed only in the squeezed vacuum produced by the DPA. The two lines of the Autler-Townes absorption spectrum can be narrowed only in a narrow bandwidth squeezed vacuum, whereas they are independent of the phase and are always broadened in a broadband squeezed vacuum.

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Carbohydrate-deficient transferrin (CDT) has emerged as the best new marker for alcohol abuse. Recently plasma immunoglobulin A (IgA) reactivity with acetaldehyde (AcH)-modified proteins, or the modified proteins per se, have been proposed as a markers for high levels of alcohol consumption. In this study, we have compared CDT, IgA reactivity with AcH adducts (IgA ASR), and AcH-modified albumin with conventional markers of high alcohol intake in groups with well-defined drinking histories, The plasma activity of ALT, AST, and gamma-glutamyltransferase increased steadily with increasing alcohol consumption, CDT and AcH-modified albumin showed a similar pattern, whereas IgA ASR appeared only to be elevated after a threshold level of consumption had been reached, Neither CDT IgA ASR or AcH-modified albumin correlated strongly with any of the conventional markers or each other. This study shows that CDT, IgA ASR, AcH-modified albumin, and the conventional markers are not related, but suggests that the concurrent use of CDT and IgA ASR may lead to better identification of high alcohol intake.

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The Parkes Half-Jansky Flat-Spectrum Sample contains a large number of sources with unusually red optical-to-near-infrared (NIR) continua. If this is to be interpreted as extinction by dust in the line of sight, then associated material might also give rise to absorption in the soft X-ray regime. This hypothesis is tested using broadband (0.1-2.4 keV) data from the ROSAT All-Sky Survey. Significant (>3 sigma confidence level) correlations between the optical (and NIR)-to-soft X-ray continuum slope and optical extinction are found in the data, consistent with absorption by material with metallicity and a range in the gas-to-dust ratio as observed in the local ISM. Under this simple model, the soft X-rays are absorbed at a level consistent with the range of extinctions (0 < A(V) < 6 mag) implied by the observed optical reddening. Excess X-ray absorption by warm (ionized) gas, (i.e., a warm absorber) is not required by the data.

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We present numerical and analytical results for the Mollow probe absorption spectrum of a coherently driven two-level system in a narrow bandwidth squeezed vacuum field. The spectra are calculated for the case where the Rabi frequency of the driving field is much larger than the natural linewidth and the squeezed vacuum carrier frequency is detuned from the driving laser frequency. The driving laser is on resonance. We show that in a detuned squeezed vacuum the standard Mellow features are each split into triplets. The central components of each triplet are weakly dependent on the squeezing phase but the sidebands strongly depend on the phase and can have dispersive or absorptive/emissive profiles. We also derive approximate analytical expressions for the spectral features and find that the multi-peak structure of the spectrum can be interpreted either via the eigenfrequencies of a generalized Floquet Hamiltonian or in terms of three-photon transitions between dressed stales involving a probe field photon and a correlated photon pair from the squeezed vacuum field.

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Aims Topical sunscreens are routinely applied to the skin by a large percentage of the population. This study assessed the extent of absorption of a number of common chemical sunscreen agents into and through human skin following application of commercially available products. Methods Sunscreen products were applied to excised human epidermis in Franz diffusion cells with the amount penetrating into and across the epidermis assessed by h.p.l.c. for 8 h following application. Results All sunscreen agents investigated penetrated into the skin (0.25 g m(-2) or 14% of applied dose), but only benzophenone-3 passed through the skin in significant amounts (0.08 g m(-2) or 10% of the applied dose). With one exception, suncreen agents in corresponding products marketed for adults and children had similar skin penetration profiles. Conclusions Whilst limited absorption across the skin was observed for the majority of the sunscreens tested, benzophenone-3 demonstrated sufficiently high penetration to warrant further investigation of its continued application.

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In a randomized trial involving 71 postmenopausal osteoporotic women with vertebral compression fractures, radiocalcium absorption studies using the Ca-45 single isotope method (alpha) were performed at baseline and after 8 months of treatment with either continuous combined hormone replacement therapy (HRT, as piperazine estrone sulfate 0.625-0.937mg daily +/- medroxyprogesterone acetate 2.5 mg daily depending on uterine status) or HRT plus calcitriol 0.25 mu g twice daily. A calcium supplement of 600 mg nocte was given to only those women who had a daily calcium intake of less than 1 g per day at baseline, as assessed by recalled dietary intake. There was a significant decrease 0.74 (+/- 0.35 SD) to 0.58 (+/- 0.22), Delta alpha = -0.17 (+/- 0.26), p<0.0005] in alpha at 8 months compared with baseline in the HRT-treated group, but a significant increase [0.68 (+/- 0.31) to 0.84 (+/- 0.27), Delta alpha = +0.16 (+/- 0.30), p<0.003] in the HRT-plus-calcitriol treated patients, resulting in alpha being significantly higher after 8 months in the latter group than in the HRT-only group. Although 72% of the patients had been supplemented with calcium between the first and second studies, separate analyses revealed that the change in calcium intake had not affected the result. Further breakdown of the groups into baseline 'normal' absorbers (alpha greater than or equal to 0.55) and 'malabsorbers' (alpha <0.55) revealed that alpha decreased with HRT treatment only in the normal absorbers, and remained stable in the malabsorbers. Conversely, following HRT plus calcitriol treatment, alpha increased only in the malabsorbers, the normal absorbers in this group remaining unchanged. In conclusion, our data show that HRT, of the type and dose used in this study, did not produce an increase in absorption efficiency; it was in fact associated with a fall. increased absorption efficiency cannot be achieved unless calcitriol is used concurrently, and then only in patients with malabsorption. Calcitriol also had a significant effect in normal absorbers in that it prevented the decline in alpha seen with HRT alone, and thus should be considered in all patients with postmenopausal osteoporosis treated with HRT.

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Plant performance is, at least partly, linked to the location of roots with respect to soil structure features and the micro-environment surrounding roots. Measurements of root distributions from intact samples, using optical microscopy and field tracings have been partially successful but are imprecise and labour-intensive. Theoretically, X-ray computed micro-tomography represents an ideal solution for non-invasive imaging of plant roots and soil structure. However, before it becomes fast enough and affordable or easily accessible, there is still a need for a diagnostic tool to investigate root/soil interplay. Here, a method for detection of undisturbed plant roots and their immediate physical environment is presented. X-ray absorption and phase contrast imaging are combined to produce projection images of soil sections from which root distributions and soil structure can be analyzed. The clarity of roots on the X-ray film is sufficient to allow manual tracing on an acetate sheet fixed over the film. In its current version, the method suffers limitations mainly related to (i) the degree of subjectivity associated with manual tracing and (ii) the difficulty of separating live and dead roots. The method represents a simple and relatively inexpensive way to detect and quantify roots from intact samples and has scope for further improvements. In this paper, the main steps of the method, sampling, image acquisition and image processing are documented. The potential use of the method in an agronomic perspective is illustrated using surface and sub-surface soil samples from a controlled wheat trial. Quantitative characterization of root attributes, e.g. radius, length density, branching intensity and the complex interplay between roots and soil structure, is presented and discussed.

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A number of mathematical models have been used to describe percutaneous absorption kinetics. In general, most of these models have used either diffusion-based or compartmental equations. The object of any mathematical model is to a) be able to represent the processes associated with absorption accurately, b) be able to describe/summarize experimental data with parametric equations or moments, and c) predict kinetics under varying conditions. However, in describing the processes involved, some developed models often suffer from being of too complex a form to be practically useful. In this chapter, we attempt to approach the issue of mathematical modeling in percutaneous absorption from four perspectives. These are to a) describe simple practical models, b) provide an overview of the more complex models, c) summarize some of the more important/useful models used to date, and d) examine sonic practical applications of the models. The range of processes involved in percutaneous absorption and considered in developing the mathematical models in this chapter is shown in Fig. 1. We initially address in vitro skin diffusion models and consider a) constant donor concentration and receptor conditions, b) the corresponding flux, donor, skin, and receptor amount-time profiles for solutions, and c) amount- and flux-time profiles when the donor phase is removed. More complex issues, such as finite-volume donor phase, finite-volume receptor phase, the presence of an efflux. rate constant at the membrane-receptor interphase, and two-layer diffusion, are then considered. We then look at specific models and issues concerned with a) release from topical products, b) use of compartmental models as alternatives to diffusion models, c) concentration-dependent absorption, d) modeling of skin metabolism, e) role of solute-skin-vehicle interactions, f) effects of vehicle loss, a) shunt transport, and h) in vivo diffusion, compartmental, physiological, and deconvolution models. We conclude by examining topics such as a) deep tissue penetration, b) pharmacodynamics, c) iontophoresis, d) sonophoresis, and e) pitfalls in modeling.

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Background. Carbamazepine (Carba) is an anticonvulsant and psychotropic drug used widely for the treatment of intellectual disability and severe pains, but the incidence of hyponatremia is a common related occurrence. This hyponatremia is frequently attributed to a SIADH induced by this drug. It is also known that Carba is used to decrease the urinary volume in Diabetes Insipidus (DI) because it has an antidiuretic effect. Lithium (Li) is one of the most important drugs used to treat bipolar mood disorders. However Li has the undesirable capacity to induce DI. Nowadays, the association of these drugs is used in the treatment of patients with psychiatric and neurological problems. Methods. In vivo and in vitro (microperfusion) experiments were developed to investigate the effect of Carba in the rat Inner Medullary Collecting Duct (IMCD). Results. The results revealed that Carba was able to stimulate the V2 vasopressin receptor-Protein G complex increasing the water permeability (Pf) and water absorption. In vivo studies showed that in rats with lithium-induced DI, Carba decreased the urinary volume and increased the urinary osmolality. AQP2 expression was increased both in normal IMCD incubated with Carba and in IMCD from lithium-induced DI after Carba addition to the diet, when compared with the control. Conclusion. These results showed that the hyponatremia observed in patients using this anticonvulsant drug, at least in part, is due to the Carba capacity to increase IMCD`s Pf and that the Lithium-Carbamazepine association is beneficial to the patient.

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Background: Many questions remain unanswered about premature atherosclerosis in rheumatoid arthritis (RA). Besides inflammation, some studies have suggested the role of autoantibodies on its pathogenesis. Objective: The aim of this study was to investigate the presence of antibodies against phospholipids, beta2-glycoproteinl (beta2-gpl), lipoprotein lipase, and heat shock proteins (Hsp) in RA patients and to evaluate their possible association with subclinical carotid atherosclerosis. Methods: Seventy-one RA patients and 53 age- and sex-matched controls were selected to perform anticardiolipin antibodies (aCL) (IgG and IgM), anti-beta2-gpl (IgG, IgM, and IgA), anti-lipoprotein lipase (anti-LPL), anti-Hsp 60, and anti-Hsp 65 by ELISA tests. Intima-medial thickness (IMT) of common carotid and presence of plaques were assessed by high-resolution B-mode ultrasonography. Exclusion criteria were smoking, diabetes, and arterial hypertension. Lipoproteins, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and fibrinogen levels, as well as health assessment questionnaire (HAQ) and disease activity score (DAS) 28 were also evaluated. Results: Age (48.93 +/- 12.31 vs. 45.37 +/- 9.37 years; p = 0.20) and body mass index (BMI) (p = 0.69) were similar in RA and controls, as well as female gender (p = 0.56). The mean IMT was similar between RA and controls (0. 721 +/- 0.16 vs. 0.667 +/- 0.14 turn, p = 0.07) but the frequency of plaques was higher in RA (14.1% vs. 1.9%; p = 0.02). In RA patients, IMT measurements did not differ according to the presence or absence of these antibodies: IgG aCL (0.62 +/- 0.64 vs. 0.72 +/- 0.17 mm, p = 0.24), IgM aCL (0.65 +/- 0.79 vs. 0.73 +/- 0.17 mm, p = 0.33), anti-Hsp 60 (0.78 +/- 0.20 vs. 0.71 +/- 0.16 mm, p = 0.27), anti-Hsp 65 (0.73 +/- 0.16 vs. 0.72 +/- 0.17 mm, p = 0.77), IgG anti-beta2-gpl (0.73 +/- 0.16 vs. 0.71 +/- 0.17 mm, p = 0.72), and anti-CCP (0.71 +/- 0.16 vs. 0.76 +/- 0.20 mm, p = 0.36). In addition, IMT did not correlate with antibodies titers: IgG aCL (r = -0.09, p = 0.47), IgM aCL (r = - 0.15, p = 0.21), anti-Hsp 60 (r = 0.10, p = 0.42), anti-Hsp 65 (r = 0.05, p = 0.69), IgG anti-beta2-gpl (r = - 0.07, p = 0.57), IgM anti-beta2-gpl (r = - 0.05, p = 0.69), IgA anti-beta2-gpl (r = 0.03, p = 0.79), and anti-CCP (r = - 0.07, p = 0.57). RA patients with plaques had a significantly higher age compared to those without plaques (p = 0.001), as well as higher mean IMT (p < 0.001), total cholesterol (p = 0.001), and LDL (p = 0.003). Conclusions: In RA a clear association between all autoantibodies studied herein and increased IMT or presence of plaques was not observed. The great prevalence of carotid atherosclerosis in RA was related to age, total and LDL cholesterol, as identified in normal population. (c) 2008 Elsevier Masson SAS. All rights reserved.

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Background: Anti-lipoprotein lipase antibodies have been described in rare cases of patients with hypertriglyceridemia. However, no systematic study evaluating these antibodies in patients with this lipid abnormality has been undertaken. Objectives: To analyze the correlation of anti-lipoprotein lipase (anti-LPL) antibodies with other laboratory findings in patients with hypertriglyceridemia but no autoimmune disease. Methods: We evaluated 44 hypertriglyceridemic patients without autoimmune disease. Clinical and laboratory evaluations included analyses of comorbidities, fasting lipid profile and anti-LPL antibodies. Results: Mean patient age was 55 +/- 10 years; 46% of the patients were female and 64% were Caucasian. The mean disease duration was 94.4 months and mean body mass index 28.7 +/- 3.6 kg/m(2); 34.0% were diabetic, 25.0% were obese, 72.7% had systemic arterial hypertension, 75% were sedentary, 15.9% were smokers, 56.8% had a family history of dyslipidemia, 45.5% had a family history of coronary insufficiency, 20.5% had acute myocardial infarction, 9.0% had undergone revascularization and 11.0% angioplasty, 79.5% were being treated with statins and 43.2% were taking fibrates. Median triglyceride levels were 254 mg/dl (range 100-3781 mg/dl), and total cholesterol level was 233 +/- 111 mg/dl. High-density lipoprotein was 42.6 +/- 15.4 mg/dl, low-density lipoprotein 110.7 +/- 42.4 mg/dl and very low-density lipoprotein 48 +/- 15 mg/dl. Anti-LPL antibodies were identified in 2 patients (4.5%), both of whom had a family history of dyslipidemia, coronary insufficiency and acute myocardial infarction; one had undergone myocardial revascularization and percutaneous transluminal coronary angioplasty, and both were using fibrates and had normal triglyceride levels. Conclusions: Our findings demonstrate a correlation between the immune response and dyslipoproteinemia in hypertriglyceridemic patients, suggesting that autoimmune disease contributes to the dyslipidemia process.

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Background: The antiatherogenic functions of high density lipoprotein (HDL-C) include its role in reverse cholesterol transport, but to what extent the concentration of HDL-C interferes with the whole-body cholesterol metabolism is unknown. Therefore, we measured markers of body cholesterol synthesis (desmosterol and lathosterol) and of intestinal cholesterol absorption (campesterol and beta-sitosterol) in healthy subjects that differ according to their plasma HDL-C concentrations. Methods: Healthy participants presented either low HDL-C (<40 mg/dl, n = 33,17 male and 16 female) or high HDL-C (>60 mg/dl, n = 33, 17 male and 16 female), BMI <30 kg/m(2), were paired according to age and gender, without secondary factors that might interfere with their plasma lipid concentrations. Plasma concentrations of non-cholesterol sterols were measured by the combined GC-MS analysis. Results: Plasma desmosterol did not differ between the two groups; however, as compared with the high HDL-C participants, the low HDL-C participants presented higher concentration of lathosterol and lower concentration of the intestinal cholesterol absorption markers campesterol and beta-sitosterol. Conclusion: Plasma concentrations of HDL, and not the activities of LCAT and CETP that regulate the reverse cholesterol transport system, correlate with plasma sterol markers of intestinal cholesterol absorption directly, and of cholesterol synthesis reciprocally. (C) 2010 Elsevier B.V. All rights reserved.

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Two humanized monoclonal antibody constructs bearing the same variable regions of an anti-CD3 monoclonal antibody, whole IgG and FvFc, were expressed in CHO cells. Random and site-specific integration were used resulting in similar expression levels. The transfectants were selected with appropriate selection agent, and the surviving cells were plated in semi-solid medium for capture with FITC-conjugated anti-human IG antibody and picked with the robotic ClonePix FL. Conditioned media from selected clones were purified by affinity chromatography and characterized by SDS-PAGE, Western-blot, SEC-HPLC, and isoelectric focusing. Binding to the target present in healthy human mononuclear cells was assessed by flow cytometry, as well as by competition between the two constructs and the original murine monoclonal antibody. The humanized constructs were not able to dislodge the murine antibody while the murine anti-CD3 antibody could dislodge around 20% of the FvFc or IgG humanized versions. Further in vitro and in vivo pre-clinical analyses will be carried out to verify the ability of the humanized versions to demonstrate the immunoregulatory profile required for a humanized anti-CD3 monoclonal antibody.