AB STRACT It was investigated whether or not the human blood group isoantibodies A and B could be induced by immunogenic stimuli via natural routes with a kind of antigenic substance to which all humans are commonly exposed, or if the appearance of these antibodies is independent of antigenic stimuli as has long been believed.Escherichia coli O, which possess high human blood group B and faint A activity in vitro, were fed to healthy humans and those with intestinal disorders. 80% of the sick individuals of blood group 0 and A responded with a significant rise of anti-B antibodies which was frequently de novo in infants; significant increase of anti-A isoantibodies among blood group 0 individuals was less frequent. Over one-third of the healthy individuals also had a significant isoantibody increase. Intestinal lesions favor isoantibody stimulation by intestinal bacteria; this view was supported by the study of control infants. Persons of blood group A responded more frequently with anti-B and anti-E. coli 086 antibody production than those of blood group 0. Isoantibody increase was accompanied with antibody rise against E. coli O. Inhalation of E. coli 086 or blood group AH(0)-specific hog mucin also evoked isoantibodies.The induced isoantibodies were specifically inhibited by small amounts of human blood group substances. E. coli Ow-induced anti-blood group antibodies in germfree chickens and preexisting blood group antibodies in ordinary chickens were neutralized by intravenous injection of E. coli O lipopolysaccharide.This study demonstrates that human isoantibodies A and B are readily elicited via physiological routes, by

While anti-human blood group B agglutinins are present in the majority of ordinary White Leghorn chicks by the age of 30 days, none could be demonstrated in germfree chicks up to the age of 60 days. Anti-B agglutinins in trace amounts were first found in germfree chicks 66 days old and increased to an average titer of about 1:2 by 91 days of age. This titer amounts to about 10 per cent of that found in ordinary chicks. The appearance of antibody in low titer is attributed to trace amounts of non-living antigenic contaminants penetrating the germfree barrier. The necessity of appropriate absorption in order to obtain well defined specificities was pointed out. Several means commonly used to differentiate between normal and immune antibodies were employed in this investigation. None showed a difference between anti-B agglutinins from ordinary chicks and from germfree chicks intentionally immunized with blood group B active E. coli O86 or with B active preparations from human meconium. The implications of these findings on the origin of natural agglutinins are discussed. It is concluded, that measurable anti-human blood group B agglutinins in White Leghorn chicks are acquired early in life and are not inherited. The possibilities as well as limitations of present day germfree technique for this kind of immunological research have been considered.

The capillary pressure (ψ) in unsaturated porous media is known to be a function of temperature (T). Temperature affects the surface tension (σ) of the pore water, but possibly also the angle of contact (γ). Because information on the temperature dependence of γ in porous media is rare, we conducted experiments with three wettable soils and their hydrophobic counterparts. The objectives were (i) to determine the temperature dependence of the water retention curve (WRC) for wettable and water-repellent soils, (ii) to assess temperature effects on the apparent contact angle γ A derived from those WRCs, and (iii) to evaluate two models (Philip-de Vries and Grant-Salehzadeh) that describe temperature effects on ψ. Columns packed with natural or hydrophobized soil materials were first water saturated, then drained at 5, 20, and 38°C, and rewetted again to saturation. Capillary pressure and water content, θ, at five depths in the columns were measured continuously. The observations were used to determine the change in γ A with T, as well as a parameter β 0 that describes the change in ψ with T It was found that the Philip-de Vries model did not adequately describe the observed relation between ψ and T A mean value for β 0 of −457 K was measured, whereas the Philip-de Vries model predicts a value of −766 K. Our results seem to confirm the GrantSalezahdeh model that predicts a temperature effect on γ A For the sand and the silt we studied, we found a decrease in γ A between 1.0 to 8.5°, when the temperature was increased from 5 to 38°C. Both β 0 and γ A were only weak functions of θ. Furthermore, it seemed that for the humic soil under study, surfactants, i.e., the dissolution of soil organic matter, may compound the contact angle effect of the soil solids. RightsWorks produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted. Chahal (1964Chahal ( , 1965, reported that neither entrappedThe capillary pressure ( ) in unsaturated porous media is known

Group B streptococci remain a serious cause of morbidity and mortality in neonates. GBS vaccine or immunoglobulin administered iv may enhance neonatal GBS immunity. Likewise, intrapartum antibiotic therapy of colonized mothers appears to reduce vertical transmission of group B streptococci and to prevent both maternal and neonatal GBS disease. However, the safety and effectiveness of routine penicillin prophylaxis less than or equal to 1 hr after birth remain in question. For example, penicillin prophylaxis appears to be of little value in infants with low birth weights (less than 2,000 g) who become symptomatic shortly after birth; however, it may reduce the incidence of disease in larger, full-term infants who acquire the group B streptococci at delivery or in the few hours immediately thereafter. The potential harm of administering penicillin to all neonates must also be considered, since routine antibiotic therapy may alter the incidence of both neonatal infections due to penicillin-resistant pathogens and possible later penicillin allergy. Theoretically, a single injection of penicillin at birth may suppress GBS disease in some neonates but not effectively treat it, allowing the disease to progress prior to diagnosis and therapy. The decision to use penicillin routinely in neonates to prevent GBS disease must therefore be made with caution. Presently, this decision must be made on a situational basis, with institutions having a high incidence of early-onset GBS disease electing to use penicillin only if the potential benefits outweigh the risks.