Aging and immunoglobulin isotype patterns in oral tolerance.

In the present review we address oral tolerance as an important biological phenomenon and discuss how it is affected by aging. Other factors such as frequency of feeding and previous digestion of the antigen also seem to influence the establishment of oral tolerance. We also analyze immunoglobulin isotypes of specific antibodies formed by tolerant and immunized animals of different ages submitted to different conditions of oral antigen administration.

Remote daytime measurements of tropospheric temperature profiles with a rotational Raman lidar.

Tropospheric temperature profiles have been measured at daytime with a rotational Raman lidar. The lidar operates in the solar-blind spectral region with KrF laser radiation that is Raman shifted in hydrogen to 276.787 nm.

Raman-shifted KrF laser radiation with low amplified spontaneous emission for a rotational Raman daytime-temperature lidar.

Various configurations of a tunable two-stage KrF laser have been investigated for providing powerful laser pulses with very low amplified spontaneous emission (ASE). The lowest fraction (0.00017%) of ASE was attained with a single-pass amplifier and a phase-conjugate Brillouin mirror.

Systemic immunization of mature mice by the oral route.

1. Mice of several strains which are susceptible to the induction of oral tolerance by a single gavage with 20 mg of ovalbumin (Ova) when young adults (7-8 weeks old) become less susceptible or refractory to tolerance induction when mature (20-40 weeks old). The antibody-forming capacity of these mature animals remains invariant compared to young adults (8-10 weeks old).

A toxoid prepared from cholera toxin by iodination.

A cholera toxoid was prepared by iodinating purified cholera toxin having an activity of 25 Limit of blueing (Lb) doses/1 microgram with 0.8 mumol of iodine monochloride per mg toxin, and the residual lesion capacity was tested in mice. The blueing dose (BD) test was strongly positive for the native toxin, and completely abolished in the iodinated toxoid when tested at up to 25 times on Lb dose.