72,437 research outputs found
Effects of precipitation conditions on the membrane morphology and permeation characteristics
[[abstract]]The permeability and permselectivity of asymmetric and particulate membranes towards glucose and proteins of various molecular sizes were studied. It was found that the skin layer of asymmetric membranes was permeable to glucose and insulin but effectively prevent the permeation of immunoglobulins. This result parallels our interest for the development of artificial pancreas. It was also found that skinless particulate membranes exhibited not only high permeation rates with respect to albumin and immunoglobulins but also good selectivity between these components. Thus, particulate membranes has the potential to be used in separating albumin from immunoglobulins for treating disorders related to immunoglobulin abnormalities.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[incitationindex]]E
Comparison of serum immunoglobulin G half-life in dairy calves fed colostrum, colostrum replacer or administered with intravenous bovine plasma.
In calves, passive immunity of immunoglobulins can be acquired through ingestion of colostrum or colostrum replacers. Plasma can been used to supplement immunoglobulins in healthy or sick calves. Serum half-life of colostral derived immuglobulin G (IgG) is estimated to be 20 days. Half-life of IgG is important in determining response to antigens and timing of vaccination in calves. To date studies evaluating half-life of colostrum replacer or plasma derived IgG are lacking. The objectives of this study were to compare the serum half-life of IgG derived from colostrum, colostrum replacer and plasma in dairy calves reared up to 35 days of age. Thirty Jersey calves were randomly assigned to receive colostrum or colostrum replacer by oroesophageal tubing or plasma by intravenous administration. Serum samples were collected at 2, 5, 7, 10, 14, 21, 28 and 35 days. Serum IgG concentrations were determined by radial immunodiffusion. The results indicated that half-life for IgG in colostrum fed (28.5 days) or plasma transfused calves (27.3 days) was longer than colostrum replacer fed calves (19.1 days). Further studies are required to evaluate pathogen specific immunoglobulins in order to recommend vaccination timing in calves fed colostrum replacers
Alterations in immunoglobulin levels in uninfected children born to HIV infected women
Background
Immunoglobulin levels are known to be elevated in HIV infected children. However, little is known about the effect of maternal HIV infection and the maternal altered immune system on immunoglobulin levels in uninfected children. As few data are available on immunoglobulins from young healthy children, we used data from uninfected children born to hepatitis C virus (HCV) infected women as a comparison.
Methods
Prospective data on immunoglobulin levels were available from birth to 5 years for children enrolled in the European Collaborative Study (ECS) of children born to HIV-1 infected women and from birth to 24 months for children enrolled in the European Paediatric HCV Network (EPHN). Children born to HIV/HCV co-infected women were excluded. Smoothers (running means) illustrated patterns of immunoglobulins over age by infection status. Associations between infant and maternal factors and child log10 total IgG, IgM and IgA levels were quantified in linear regression analyses allowing for repeated measures within child. Further analyses were performed using only data of HIV exposed uninfected children to investigate associations between child immunoglobulins and maternal immunological and virological factors and anti-retroviral therapy exposure.
Results
1751 HIV uninfected, 190 HIV infected children (ECS), 173 HCV uninfected and 30 HCV infected children (EPHN) were included. HIV infected children had higher levels of all immunoglobulins compared to uninfected children over all ages. HIV uninfected children had significantly higher IgG, IgM and IgA levels than HCV uninfected children upto at least 24 months, adjusting for gender, prematurity and race. Prematurity was associated with significantly lower levels of immunoglobulins upto 24 months. Children born to African women had higher IgG and IgA levels upto 24 months than those born to white women but lower IgM in the first 6 months.
Among HIV uninfected children higher IgG levels were associated with elevated maternal IgG levels, as well for measurements from 18 months to 5 years of age. No significant effect of maternal CD4 count was observed. ART exposure was associated with significantly lower IgG levels at 6-24 months. Race was not associated with immunoglobulin levels in multivariable analyses in this sub-group.
Conclusions
These findings indicate significant alterations in immunoglobulin levels in uninfected children born to HIV infected women. This suggests that exposure to an activated maternal immune system is associated with an altered humoral response in children without antigen stimulation, and warrants further research
Antagonistic Autoantibodies to Insulin-Like Growth Factor-1 Receptor Associate with Poor Physical Strength
Natural autoantibodies to the IGF1 receptor (IGF1R-aAb) have been described in relation to Graves' ophthalmopathy. Other physiological roles of natural IGF1R-aAb are not known. We hypothesized that IGF1R-aAb may be related to muscle development. Serum samples (n = 408) from young overweight subjects (n = 143) were collected during a lifestyle intervention study. Anthropometric parameters, along with leptin, IGF1 and IGF1R-aAb concentrations, were analyzed, and the subjects were categorized into positive or negative for IGF1R-aAb. Eleven out of 143 subjects (7.7%) were positive for IGF1R-aAb. Identified IGF1R-aAb were molecularly characterized and showed antagonistic activity in vitro impairing IGF1-mediated IGF1R activation. Mean body weight, height or age were similar between IGF1R-aAb-positive and -negative subjects, but IGF1 concentrations differed. Jumping ability, as well as right and left handgrip strengths, were lower in the IGF1R-aAb-positive as compared to the IGF1R-aAb-negative subjects. We conclude that natural IGF1R-aAb are detectable in apparently healthy subjects and are capable of antagonizing IGF1-dependent IGF1R activation. Moreover, the presence of IGF1R-aAb is associated with poor physical strength. Although the causality of this association is unclear, the data imply a potential influence of IGF1R autoimmunity on muscle development
Effect of Direct-Fed Microbials and Enzyme Supplementation in Prepartum Holstein Cows on Colostrum and Calf Immunity
In cows, colostrum is composed of several antibodies and nutrients to provide immunity and energy to the calf. Feeding calves high quality colostrum has been shown to improve calf health, leading to reduced mortality in calves and greater milk production in cows. The addition of direct-fed microbials (DFM) to cow diets has been theorized to improve feed efficiency and milk production, with studies showing mixed results. However, few experiments have studied the effect of feeding DFM on colostrum quality. In this experiment two treatments were given, 1) DFM and 2) DFM and enzymes (DFME). Colostrum was analyzed to determine if yield, composition, and immunoglobulin (IgG and IgA) concentration were affected. Calf serum IgG and IgA concentrations were analyzed to determine if 24 h concentrations and apparent efficiency of absorption (AEA) were affected. There were no differences with regard to yield or IgA concentration. The percent of ash showed a positive trend, indicating a higher percentage with the treatments (P = 0.067). The treatments had no effect on the additional components analyzed. The results for the IgG concentration were not significant although an increase was observed from 79.1 mg/mL in the control to 91.1 mg/mL in the DFME treatment. Neither treatment had an effect on calf immunoglobulin concentration or AEA. Based on the results, feeding DFM or DFME improves percent ash and might increase IgG concentration, but further research is necessary
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