The use of human placenta for purification of normal and immune animal sera

There was described and efficient and economical approach for the removal of toxic substances from normal and immune sera from various species of animals with the use of human placenta tissue. Purification brings about to perceptible losses of neither serum-specific activity nor the original volume. Being simple the method does not require any special equipment and can be used in conditions of low-volume or in laboratory production of serum preparations. There are considered as well possible origins of serum toxicity as mechanism of antitoxic activity of placenta.

FATE OF DEFINED ANTIGENS IN THE NEWBORN CHIMPANZEE

Seven newborn chimpanzees injected at the time of birth with BSA and HoGG cleared the injected antigens at an exponential rate without evident antibody production following initial injection. When challenged with the same antigens, 4 of 7 injected with BSA and 4 of the 6 injected with HoGG were immune. Tolerance of BSA was seen in 3 of 7 chimpanzees and tolerance of HoGG in 2 of 6 chimpanzees. The initial response to BSA and HoGG of both the adult and newborn chimpanzees is an exponential decay of the antigen without a rapid phase of degradation. Re-injection of the antigens in an immune animal results in a rapid clearance and antibody production. These data suggest that newborn primates may react immunologically to foreign proteins either by antibody production or by immunological tolerance—the inhibition of antibody production to subsequent exposures to the same antigen. The dosage, maturity, and other factors which determine which outcome will follow a given exposure are not revealed by these studies. Therefore, it must be assumed that newborn primates, including humans, may be sensitized by foreign proteins administered parenterally or orally.

STUDIES ON THE MECHANISM OF IMMUNITY IN TYPHUS FEVER

The intradermal inoculation of Mexican typhus virus into immune guinea pigs produces a local reaction which is similar in its appearance to the lesion observed in the skin of normal animals submitted to the same treatment. The reaction in the immune animal appears earlier and fades sooner than the lesion in the normal guinea pig. The inoculation of heat-killed or formalin-killed Rickettsiae produces no significant reactions at the site of the intradermal injection in typhus immune guinea pigs. The virus, inoculated intradermally, has been recovered from the local lesion 72 hours after the injection into typhus immune guinea pigs. Normal guinea pigs and persons without a history of typhus fever present a congestion and some swelling of the skin at the site of the intradermal injection of formalinized Mexican Rickettsiae. The reaction appears 24 hours after the inoculation and fades within 48 hours. Heating the formalinized Rickettsia suspensions at 70°C. for 30 minutes renders them inactive in normal men and guinea pigs. From the experiments reported in this paper it seems that the reactions observed in typhus immune guinea pigs submitted to a second inoculation of typhus virus, belong to the group of reactions presented by tuberculous animals (Koch's phenomenon) and the accelerated takes shown by immune persons submitted to revaccination with vaccinia virus. A heat labile substance has been demonstrated in the formalinized Rickettsia bodies, which produces a reaction in the skin of normal men and guinea pigs.

THE FATE OF ANTIGEN (PROTEIN) IN AN ANIMAL IMMUNIZED AGAINST IT

When proteins such as horse serum or crystalline egg albumin which have been selected because they produce the phenomena of immunity are introduced into a normal animal they diffuse widely in the tissue, enter the blood stream, and are disseminated throughout the body. The same substances introduced into an immune animal are fixed at the site of entry and are not found in the blood. When protein is injected into the skin of an immune animal acute inflammation (Arthus phenomenon) occurs at the site of injection and brings about destruction of the foreign substance.

Observations on the Evolution of Immunity in Disease

The following experiments constitute an attempt to follow out in detail the stages by which immunity is established, in the course of a generalised bacterial infection (Pseudotuberculosis of rabbits). Two aspects of immunity are considered, firstly the presence, in the circulating fluids, of specific antibacterial substances, and secondly the power of rapidly producing such substances in answer to the specific stimulus. That is to say, attention is directed, not only to the quantity of specific antibodies present on any day of the disease, but also to the response which the animal can make to various doses of bacterial vaccine. For the immune animal is both more vigorous and more sensitive than the normal, in its reaction to a renewed dose of poison (Wassermann and Citron, 1905). Naturally the facts established with regard to one disease only, cannot be predicated at once of other diseases, in other animals. Still it is hoped that the systematic study of one disease may give some help in coordinating the large but somewhat disjointed mass of clinical observation which is already available.