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Red cell agglutination which is not related to reaction between antibody and antigen may be caused by a number of so-called nonspecific effects. For example, high serum protein levels (i.e. high gamma-globulin) may give false positive results in some blood typing tests1. The agglutination produced by such agents may usually be reversed following dilution with saline. The purpose of this paper is to describe and characterize an unusual cold precipitable and water precipitable serum globulin which was able to cause rapid irreversible agglutination of red cells under the conditions of slide typing techniques. Because this globulin was present in sera of Rh-negative persons who were mistakenly typed as Rh-positive, we wish to emphasize the importance of repeated red cell washings and saline tube tests in the typing of persons who are Rh (or other blood type) negative and whose sera may also possess large amounts of proteins reactive in agglutination tests. A practical demonstration of the importance of such procedures is indicated by the following case. Late in 1955 we were afforded the opportunity of studying blood from a patient with tuberculosis and anemia who on two previous occasions (1951 and 1955) had been typed as B Rh-positive and was transfused with Rh-positive blood. Typing had been carried out using only the rapid slide technique. Repeat typing in our laboratory showed that his red cells were rapidly and irreversibly agglutinated on the slide in the presence of incomplete anti-Rh serum. However, when the tube test was carried out, his washed red cells in 2 % saline suspension were not agglutinated by anti-Rh serum. The results indicated that this Rh-negative patient had on two occasions been inadvertantly typed as Rh-positive and on both occasions was transfused with Rh-positive blood on the basis of compatible high protein cross match tests. Therefore, the blood given in 1955 represented a potent booster dose of Rh antigen as was indicated by the subsequent antibody response demonstrated only by means of the antihuman globulin technique (fig. 1). Happily, despite the

Sulfate is an important component relating to normal proteoglycan secretion and normal motility in the marine sponge, Microciona prolifera. The following alterations were observed in sponge cells when sulfate free artificial sea water was used as the suspension medium: 1) impairment of aggregation, 2) loss of cell movements, 3) a marked reduction in the secretion of the adhesion proteoglycan (AP). Reversal of this effect occurred if sulfate depleted cells were again rotated in sulfate containing artificial sea water. Motility and reaggregation of sulfate deprived cells could be completely restored by purified AP, but only if cells were first pre-conditioned in normal sea water. Comparisons of 35SO4(2-) uptake between normal and sulfate deprived cells which had been treated to reduce preformed secretions showed a marked increase in 35SO4(2-) uptake and incorporation which could be greatly augmented in the presence of Ca2+/Mg2+. Excessive retention of AP in sulfate starved cells demonstrated by immunostaining suggested that AP secretion and cellular motility may be controlled by a sulfate dependent secretogogue or that undersulfated AP itself had developed a secretory defect. SDS-PAGE of Triton treated cellular extracts demonstrated a 116 kDa 35SO4(2-) sulfated band which co-migrated with AP, but only in extracts derived from sulfate starved cells. Western blots prepared from such extracts incubated in the presence of a monoclonal anti-band 3 antibody demonstrated labelling of a single 97 kDa band only in material from sulfate deprived cells. The absence of this component in normal cell extracts indicated that this protein may be involved in facilitated sulfate transport. This study lends support to a heretofore unrecognized role for sulfate in cell motility and secretion.

Proteoglycans are associated with senile plaques in Alzheimer's disease and may be involved in A beta fibril formation and plaque formation. In vitro, glycosaminoglycans have been shown to inhibit the proteolysis of A beta fibrils, accelerate formation and maintain their stability. To model their interaction, we investigated the binding of a sulfated proteoglycan derived from a natural source; marine sponge Microciona prolifera aggregation factor (MAF). This species-specific re-aggregation of sponge cells has two functional properties, a Ca2+ independent cell binding activity and a Ca2+ dependent self-aggregation. It has been shown that a novel sulfated disaccharide and a pyruvylated trisaccharide are important in the Ca(2+)-dependent MAF aggregation. Aggregation demonstrated by homophilic binding of MAF subunits may be chemically distinct from other heterotypic binding effects. We investigated A beta-MAF interactions and show that MAF induces a structural transition in A beta 40 and A beta 42 from random to beta-structure as detected by circular dichroism spectroscopy. Electron microscopy revealed that the structural transition correlated with an increase in the number of A beta 40 and A beta 42 aggregated that have a truncated fibrillar morphology. Finally, MAF increased A beta-induced toxicity of nerve growth factor (NGF)-differentiated PC-12 cells in the absence of Ca2+. The addition of Ca2+ to MAF-A beta incubations resulted in a moderate attenuation of toxicity possibly due to a reduction in A beta-cell interactions caused by extensive lateral aggregation of the MAF-A beta complexes. Our results indicate that A beta is generally susceptible to proteoglycan-mediated aggregation and fibril formation. We also propose that the MAF model system may be useful in delineating these interactions and represent a means to develop and examine potential inhibitors of the proteoglycan effects.

The distributional patterns of blood group substance H and carcinoembryonic antigen (CEA) in 20 colorectal carcinomas from 17 patients, were investigated. Prognosis in these cases was more obviously related to histologic classification and pathologic stage than to BGS and CEA distributional patterns or preoperative plasma CEA levels. The distribution of H and CEA was similar to that found by other investigators for A and B blood group substances with the exception that areas of identical localization could be shown in at least some areas of each tumor studied that was positive for both antigens. The relationship of CEA and BGS is as yet unknown, but it seems probable that they can occur simultaneously in the same tissue.

Alternative possibilities for the establishment of the proper cell distribution during embryogenesis are summarized at the beginning, followed by an assessment of the examples known so far where cell-cell recognition is known to be mediated via cell surface components. In the second part the species-specific recognition process which occurs during the sorting-out of dissociated sponge cells is analysed since it may serve as a possible model for cell-cell recognition in higher animals. Three possible mechanisms for the establishment of proper cell distribution are considered. These include, first, chemotaxis; secondly, guidance of cell or cell sheet movement by extracellular matrix or by surrounding cells and thirdly, random movement followed by recognition at the final point of destination. Recognition is necessary for both of the two latter processes, i.e. for cell guidance as well as for locking the cells into their final position after random movement. Two basically different recognition mechanisms should be distinguished from each other. On the one hand cells may recognize each other with the help of macromolecules situated in or just outside of the plasmamembrane which fit to each other like enzymes and substrates or antibodies and antigens. On the other hand, cells may exchange information by exchanging cytoplasmatic components via vesicles or gap junctions. The species-specific aggregation of dissociated sponge cells is considered to be a possible model for cell-cell recognition in higher animals. A proteoglycan-like intercellular macromolecule called aggregation factor seems to mediate recognition of a given species of cells in the reaggregation process of dissociated cells. The data available at the present time suggest that a monovalent surface macromolecule (baseplate) may mediate the recognition process probably by recognizing the carbohydrate side chains of the multivalent proteoglycan aggregation factor. A cell-free system was devised to mimic this aggregation process. Addition of aggregation factor to baseplate-coated sepharose beads of approximately the size of the original sponge cells has essentially the same characteristics as the cellular system. Macromolecule-coded surface information for the recognition between cells has not been established during the embryogenesis of higher animals and remains an interesting challenge.

The effects of the intramuscular administration of BAL in a Negro harboring the sickle cell trait have been presented. It was observed that the rate of sickling was accelerated and the erythrocyte sedimentation rate was retarded in the presence of BAL both in vitro and apparently in vivo. However, the administration of BAL produced none of the pathologic sequelae characteristic of sickle cell disease.

The method of filter paper electrophoresis was used to study proteins and protein-bound polysaccharides in sera obtained from subjects before and after a single booster dose of diphtheria toxoid, and in sera from allergic subjects. The electrophoretic patterns of precipitating antitoxic sera resembled those found in normal non-immune sera. However, skin-sensitizing antitoxic sera were distinguished by a relatively large beta globulin component and a small or indistinct alpha2 globulin. Fusion of both components was present in some sera containing this variety of antitoxin. Considerable amounts of serum-bound polysaccharides in these sera migrated relatively slowly in contrast to the behavior of polysaccharides of precipitating antitoxic sera which migrated faster when tested under similar conditions. Alterations in proteins and carbohydrates were most readily observed in specimens containing high titers of antitoxin. There were no demonstrable differences between the electrophoretic behavior of sera obtained from subjects before or after immunization with toxoid. Electrophoretic patterns of serum from allergic subjects who developed marked eosinophilia showed attenuation of the alphas globulin associated with a relative preponderance of slow migrating protein-bound polysaccharides. These alterations were not present in sera obtained from the same persons before and after the development of eosinophilia. Changes in the proteins and polysaccharides could not be demonstrated with consistency in subjects with mild to moderate hay-fever symptoms. One person who developed severe acute hay-fever symptoms showed alterations in the beta and alpha2 globulins. Rheumatic fever subjects showed no unusual changes in the distribution of serum components. However, transition from the acute process to convalescence is graphically demonstrated by the marked decreases in gamma and alpha globulins and in protein-bound carbohydrates.

Summary Immunization with single vs. repeated doses of diphtheria toxoid was carried out in human subjects to determine the effects of the mode and schedule of administering this antigen upon antitoxin titers and upon immediate wheal responses. A similar study was carried out using repeated doses of tetanus toxoid. Schick positive persons who remained Schick positive did not develop wheal reactions to toxoid. Schick negative persons who were immunized orally did not show appreciable increases in antitoxin titer or in immediate wheal reactions. All Schick negative persons who received repeated parenteral doses of toxoid showed considerable increases in antitoxin titer and immediate wheal reactions until after the time that toxoid was discontinued. The same amount of toxoid given in one dose usually caused a marked increase in antitoxin titer up to about 3 weeks, and this was followed by a rapid decrease in titer. Wheal reactions were not present as frequently or in as marked degree in persons who received one dose of toxoid as in persons who were repeatedly immunized. Delayed reactions occurred many times in most Schick negative persons who received repeated doses of parenteral toxoid, but did not occur in persons who received only one dose of toxoid. Delayed reactions following a dose of toxoid generally occurred prior to the onset of immediate wheal reactions. Evidence is presented for the concept that immediate wheal reactions, as inflammatory responses, are coincidentally within the framework of the immune response. The degree of coincidence may be influenced by modes and schedules of immunization. These factors may be important in complex formation, and complexes may in turn provide the potential for wheal reactions.

Summary Schick tests and immunization with a single uniform dose of fluid diphtheria toxoid were carried out in two groups of persons who had not knowingly been exposed to toxoid during the preceding 5 years: a) 57 individuals with a personal or familial history of allergy, and b) 91 persons with no history of allergy. In confirmation of earlier results, it was found that immediate wheal reactions, when present, occurred in Schick negative persons but not in Schick positive persons. A history of allergy was found to be of significance in the occurrence of wheal reactions which developed in Schick negative subjects in response to toxoid. Most skin reactions were mild to moderate and were unaccompanied by reagins in the circulating blood. In confirmation of other workers, the present study indicated that personal and family histories of allergic diseases occur more frequently together than a family history in the absence of personal involvement, or a personal history in the absence of familial disease.

HeLa cells were used in the mixed agglutination reaction to determine optimal conditions for demonstrating blood group H activity by this method. The following parameters were studied in the mixed agglutination reaction: (1) derivation of cell line, (2) cell viability, (3) effects of antibody titer, (4) source and type of antibody. Studies with primary human amnion cells indicated that over a 30-day period of cultivation in vitro there were losses in specific ABO blood group activity. Addition of blood group precursors to establish human amnion cell lines FL-J and F-D indicated that blood group B antigen could be synthesized and maintained in vitro.

Amnion cells, primary and in culture, along with the infant's own erythrocytes, were tested by mixed agglutination for blood groups A, B, H, M, N, Tja, Rho(D), Yta, I and i. Studies were carried out on cell cultures ranging in age from one day to 39 days. Only A, B, H, Tja, I and i could be demonstrated on amnion cells. Decrease in the number of cells positive for Tja, and possibly for A and B, was observed in the course of cell passages. In cultures positive for H, the percentage of positive cells, although small, generally continued as long as the culture was studied.

The presence of cross-reacting hemagglutinins in fresh water catfish maintained under laboratory conditions enabled a classification of the fish into two distinct groups. The erythrocytes and serum from groups I and II used as reagents in testing other individuals permitted similar distinctions in catfish obtained from several different sources. The agglutinogen in erythrocytes from group I individuals was A-like in nature, based upon agglutination studies using lima bean lectin and human anti-A hemagglutinins; it also possessed Forssman-like activity as inferred from differential absorption studies using guinea pig kidney and bovine erythrocytes. The demonstration that hemagglutinins in group II sera were highly cross-reactive with human erythrocytes, including A1 and A1B, thus suggested a basis for interactions with group I red cells. The basis for a reciprocal effect, namely agglutination of group II cells by group I sera, was less clear, but may be related to the widespread reactivity of these sera against all human erythrocytes tested.

SummaryThis paper has described further experiences with a passive transfer technic which depends upon the ability of intradermal antitoxin to neutralize Schick toxin introduced simultaneously or later at the same sites. Partial, total or no inhibition of toxic reactions indicates the amount of antitoxin remaining at the skin sites. The amount of antitoxin which has disappeared may be calculated by difference, assuming that 1 Lf toxin = 1 Unit of antitoxin. On the basis of this test 50% of antitoxin introduced at skin sites was generally found to disappear in 10 to 14 hours. No difference in disappearance from the skin was observed between precipitating antitoxin, non-precipitating antitoxin and skin sensitizing antitoxin.

Among a group of 131 young adults tested, there was a high degree of correlation between the occurrence of immediate skin reactions of the wheal and erythema type produced by purified diphtheria toxoid and personal or familial history of allergy of the hay-fever type. Of 39 Schick-negative subjects who received a "booster" dose of purified diphtheria toxoid, 19 showed no immediate skin reactions before immunization. The development of skin sensitivity in these subjects was associated with the production of non-precipitating circulating antitoxin. Three subjects produced 20 units or more antitoxin per cc. serum following immunization, without demonstrable precipitins. Despite the fact that none showed immediate skin reactions to Schick toxoid prior to immunization, all 3 possessed a high degree of skin sensitivity to toxoid following immunization.

SummaryIn Baltimore during the past 3 years the gravis type of diphtheria bacillus has, as heretofore, been absent or rare. However, during this period there have been isolated, chiefly from clinical cases of diphtheria and contacts thereof, but also from casual carriers, many virulent and nonvirulent diphtheria bacilli characterized by (a) the production of minute colonies on blood-agar media containing potassium tellurite, and (b) slow, slight or irregular fermentation of dextrose. These characters are very frequently found together and for such organisms the designation minimus type is suggested as a convenience in discussion. Other virulent strains have been found which regularly ferment saccharose. The saccharose-fermenting strains studied do not appear to differ in other respects from ordinary diphtheria bacilli. A relationship between the minimus type of C. diphtheriae, and recent epidemiological and clinical observations in Baltimore, as well as the possible value of bacterial antigens in addition...

Erythrocytes derived from fresh water catfish, Ictalurus nebulosus (Le Sueur) and Ictalurus catus (Linneaus), referred to as groups I and II, were capable of eliciting specific immune responses as demonstrated by cross-immunization, stimulation of goats and rabbits, and absorption studies of immune antisera. Two forms of immune response were elicited in goats and rabbits, one against an antigen common to erythrocytes from individuals of groups I and II, and the other against a Forssman-like antigenic substance present on group I, but not group II, erythrocytes. The presence of two classes of immunoglobulins formed during immune responses was suggested on the basis of differences in sensitivity of agglutinins to mercaptoethanol before and after antigenic stimulation. Members of group I possessed a soluble blood group substance in serum and mucus, as demonstrated by agglutination-inhibition tests in the presence of human anti-A antiserum, lima bean lectin, and hemagglutinins in serum from group II individuals.

SummaryProperties of fractions of diphtheria antitoxic wheal reactive serum have been described. The ability of these fractions to sensitize human skin has been related to their protein and antitoxin content. Two methods of cold ethanol fractionation were employed to obtain serum components, some of which were then subfractionated electrophoretically in a starch supporting medium. The results of passive transfer tests suggest that skin sensitization is best expressed in fractions which contain gamma globulin and a non-gamma (β or α2) globulin. The point of view is adopted that the serum under consideration contains antitoxic reagins, and that they represent antitoxin whose behavior is modified by the coexistence of a labile protein protective serum factor.

Summary Five of eight brown bullhead catfish surviving a 6-week series of three immunizing injections of human secretor saliva, mixed with Freund's complete adjuvant, produced high titered heteroagglutinins against human erythrocytes of all A-B-O types. Agglutination-inhibition and cell absorption tests indicated potent fractions of activity specific for human A, B, or O erythrocytes corresponding to the A-B-O group of the secretor saliva injected. Bullfrog erythrocytes with B-like specificity were agglutinated only by the hyperimmune plasma from the catfish injected with group B saliva. Sheep erythrocytes were weakly hemolyzed but not agglutinated by the catfish plasma specimens. The usefulness of the brown bullhead catfish, both from the point of view of the quantities of blood obtainable by repeated bleedings, as well as the immunologic competence of the species to produce specific high titered antibodies in response to injected antigenic materials of major interest in human blood group studies, has been clearly established.

Summary The disappearance of I131 and I131 toxoid from injection sites was studied in the skin of normal Schick positive and Schick negative subjects. The curve of disappearance of I131 toxoid was in three phases; (1) equilibration, which occurred both in Schick positive and Schick negative persons immediately after injection; (2) exponential phase, which was observed in Schick positive persons subsequent to the equilibration phase; (3) immune elimination, which occurred in Schick negative subjects subsequent to the equilibration phase. Immune elimination appeared to be responsible for shortened survival of I131 toxoid in local sites as suggested by its relatively rapid removal from skin in the Schick negative person and in subjects who received preformed I131 toxoid antitoxin complexes. When delayed reaction occurred following I131 toxoid, there was seen an unexpected degree of retention of the isotope in Schick negative persons. Apart from variable results associated with delayed reactions, the half-life of I131 toxoid in skin sites injected with toxoid was estimated at a) 3 to 5 days in Schick positive persons; b) Immediate wheal reactions occurred commonly when I131 toxoid was present in a Schick-negative person with a high titer of circulating antitoxin. In this circumstance wheal reactions occurred in the phase of immune elimination of I131 toxoid. Two successive doses of I131 diphtheria toxoid given to each person caused wheal reactions in all instances. Delayed reactions after toxoid appeared to assist this process by slowing the release of antigen from the injection site. The data suggest that immediate wheal reactions occur in hyperimmune persons in association with the formation in skin of antigen-antibody complexes.

“Naturally occurring” isohemagglutinins and heterophilic agglutinins in 10 fresh water catfish (Ictalurus nebulosus, Le Sueur, and Ictalurus catus, Linneaus), disappeared from circulating blood following a decrease in storage temperature from 25C° to 5°C. They reappeared subsequent to an increase in storage temperature from 5°C to 25°C. The changes in agglutinating activity were accompanied by corresponding alterations in total body weight, total serum proteins and in certain electrophoretic components. It is suggested that the change in immunologic status is but one reflection of general metabolic shifts associated with fluctuations in ambient temperature.

1. The immunological properties of two contrasting types of human antisera, each containing a high titer of diphtheria antitoxin, have been investigated. 2. Sera which contain only non-precipitating antitoxin exhibit most of the properties of atopic reagin-containing sera. This type of antitoxin is capable of sensitizing normal human skin to toxin or toxoid and remains for many weeks in the injected area. It exhibits no Danysz effect, does not fix complement unless very large amounts of serum are used, and can be specifically coprecipitated by addition of precipitating antitoxin and toxin. On the other hand, it is capable of sensitizing guinea pigs to fatal anaphylactic shock. Heating at 56°C. for 4 hours destroys the skin-sensitizing properties and results in almost quantitative conversion to a modified antitoxin which is capable of blocking the wheal and erythema reaction caused by injection of toxoid into sensitized skin. Heating at 56°C. does not result in an appreciable loss of neutralizing power as judged by tests in rabbit and human skin. The anaphylactogenic property of nonprecipitating antibody is likewise unaffected by heat at 56°C. 3. Precipitating antitoxin is incapable of sensitizing normal skin to toxin or toxoid and disappears rapidly from the injected sites. It fixes complement to high titer and sensitizes guinea pigs to fatal anaphylactic shock. It was possible to demonstrate inhibition of the wheal and erythema reaction in sensitized skin by injecting certain mixtures of precipitating antitoxin and toxoid. 4. The two antitoxic sera studied in greatest detail represented extreme cases. Many persons immunized with toxoid developed both precipitating and nonprecipitating antitoxin simultaneously.

Naturally occurring anti-M antibodies were found in the serum of a five-month-old Negro twin as revealed by a discrepancy between the cell blood group and the reverse blood group. The corresponding twin did not possess this antibody. There was no apparent cause for its presence, although it was of interest that the mother was type MN. The possibility is discussed that transfer of maternal red cells to the fetus occurred and that the M agglutinogen persisted in the infant following birth until the time that it was able to respond by forming anti-M antibodies.

Summary and ConclusionThe performance of agglutination tests, using the blood cells of mice of 5 inbred strains and 8 types of F1 and F2 hybrid mice, have shown that human sera can be differentiated, apart from the usual intra-group reactions, by their ability to agglutinate mouse erythrocytes. The differentiation of human sera on this basis depended on the presence or absence of a specific agglutinin (Mo agglutinin). It was found to bear no specific relationship to either the A-B-0 blood groups or the Rh factor. Five of the 37 human sera tested (approximately 14%) did not contain the Mo agglutinin. Mouse erythrocytes adsorbed the Mo agglutinin but not α and β agglutinins or the rabbit cell agglutinin. Human erythrocytes of the a and β group and rabbit red cells adsorbed their specific agglutinins, but not the Mo agglutinin.

Publisher Summary This chapter discusses an experiment in which enzyme comparisons between normal sera derived from patients with acute myeloid leukemia, a malignancy occasionally characterized by losses in ABO blood group phenotypic expression, was studied. In the experiment, serum glycosyltransferase enzymes associated with blood groups A and H were assayed by the transfer of radioactively labeled sugars to low-molecular-weight (LMW) acceptors. In the assays for the H gene-associated (1→2)-α-L-fucosyl-transferase, phenyl β-D-galactopyranoside was used as the LMW acceptor. The chapter illustrates a figure in which the results of assays on the sera of 101 normal group O donors, 26 patients with acute myeloid leukemia, and 28 patients with non-disseminated carcinomas are summarized. The differences between normal H transferase values and those in acute leukemia do not appear to be caused by disease associated changes in the amounts of endogenous high-molecular-weight (HMW) acceptors.

Cancer-associated alterations of blood groups or their precursors occur most frequently in car-cinoma and in leukemia. Antigens most often affected are those of the ABO(H), Ii, Lewis, MNT and P systems. The blood group changes in cancer may involve one system or multiple systems. When reported in leukemias, blood group deficiencies have usually been confined to A and H antigens, but in some cases, have been accompanied by other blood group system defieiences. Gene specified a-2-L-fucosyltransferase deficiency is a common precursor abnormality in untreated acute leukemia. The changes observed in adenocarcinomata and other solid tissue tumors are varied. Some tumor cell surfaces lack or are deficient in blood group determinants, whereas, gains of antigen have been reported in other tumors, at times inappropriately expressed relative to erythrocytic determinants.

A closer orientation of blood banking toward optimal donor and patient care will depend upon an enlargement of the manpower pool of physicians with specific competence in this area. Toward this end, programs must be developed within medical school curricula, and comprehensive postgraduate training programs must be available for those interested in committing themselves fully to this specialty. Continuing education must be made available to part-time blood banking professionals in order that they remain abreast of newer developments. Recognition of their skills can now come about through competence testing and certification programs. Improvements in management of the blood resource may then be expected to occur in parallel with the increase in numbers and quality of the professionals within this unique specialty.

A controlled trial of passive immunization for prevention of post-transfusion viral hepatitis was carried out in order to determine whether effective levels of antibody were present in the "convalescent" immune serum globulin used in the study. This globulin was prepared selectively from plasma of donors giving a history of overt viral hepatitis two or more years earlier. The proportion of contributors to the globulin who had B hepatitis was unknown but the final product contained a low titer of antibody to the surface antigen of hepatitis B virus (anti-HBs). The failure of 20 ml of immune serum globulin to reduce the incidence of type B post-transfusion hepatitis (7/93) below that of placebo-treated controls (8/102) was not unexpected in view of the globulin's low titer of anti-HBs. However, more than two thirds of the post-transfusion cases were not type B and were as plentiful among globulin recipients (17/93) as among controls (17/102). Although some of the donors from whom the immune serum globulin was obtained may once have had the same type(s) of hepatitis as the non-B cases currently observed in transfusion recipients, the globulin apparently did not contain enough specific antibody to confer protection in the dose schedule tested.

Summary This study confirms the finding of a number of previous investigators that platelets show group specificity characteristics in common with red cells. Additional evidence suggests that group substance may be adsorbed to the platelet surface rather than intrinsic in the platelet. Platelet group A substance can be inactivated by a specific enzyme without apparent damage to the platelet. No increase in titratable group substance could be demonstrated after platelet lysis. Group O platelets, after incubation with soluble group A and/or B substance acquired typing characteristics similar to group A and/or B platelets. Resume Ce travail confirme les decouvertes de nombreux chercheurs suivant lesquelles les plaquettes, au meme titre que les erythrocytes, possedent les caracteristiques specifiques de groupe. De plus, il semblerait evident que les substances de groupe soient plutet absorbees a la surface des plaquettes que faisant partie integrante du stroma plaquettaire. La substance de groupe A des plaquettes peut etre inactivee par un enzyme specifique, sans toutefois que la plaquette soit alteree de maniere visible. Apres la lyse plaquettaire, on ne peut pas demontrer d'augmentation du taux des substances de groupes. Apres incubation avec des substances de groupe A ou B, les plaquettes O acquierent les caracteristiques des plaquettes des groupes A, B ou AB, respectivement. Zusammenfassung Die vorliegenden Untersuchungen bestatigen den Befund zahlreicher Autoren, das die Blutplattchen gruppenspezifische Substanzen enthalten, die in den Erythrozyten ebenfalls vorkommen. Die vorliegenden Befunde deuten darauf hin, das diese Gruppensubstanzen an der Plattchenoberflache adsorbiert sind und keine eigentlichen Zellbestandteile darstellen. Es gelingt, die A-Blutgruppensubstanz der Plattchen enzymatisch zu inaktivieren. ohne das die Plattchen nennenswert geschadigt werden. Nach Lysierung der Plattchen fand sich uberdies keine Zunahme der titrierbaren Gruppensubstanz. Plattchen von Individuen der Blutgruppe O zeigten nach Behandlung mit geloster A- bzw. B-Substanz die Eigenschaften von A- bzw. B-Plattchen.

The importance of group A hemolytic streptococcal infections in the pathogenesis of rheumatic fever is widely recognized, but little is known of the mechanism by which the streptococcal infection gives rise to the disease. The concept that an antigen-antibody interaction may be involved in the origin of the pathologic processes has received increasing attention, and recent antibody studies (1, 2) provide suggestive evidence in support of this point of view. For example, studies in several laboratories dealing with a variety of streptococcal antigens have demonstrated that the mean antibody response of a group of rheumatic fever patients to these antigens is greater than that of a comparable group of patients with uncomplicated streptococcal disease (3-6). In view of these findings, it is of importance to determine whether the hyperreactivity of rheumatic subjects is limited to antigens derived from the streptococcus or is a reflection of a fundamental difference which would be demonstrable in an enhanced response to a va

Serums from non-immunized catfish contain hightitered thermolabile hemolytic activity for all human red cells, and for red cells of other species such as rabbits. However, after heat inactivation, these sera only weakly agglutinate human red cells. After immunization with human saliva from A-B-H secretors, catfish produce potent agglutinins which clump to approximately the same high titer human red cells of all A-B-O blood groups as well as red cells from anthropoid apes (chimpanzees and gibbons). These sera do not agglutinate red cells from human beings of the Bombay type, or monkey red cells (baboon), or animal red cells (sheep). The antibody responsible for these reactions has been designated anti-Z and detects a serological specificity (blood factor) which is inhibited by A-B-H secretor saliva, and which appears to be closely associated with A-B-H blood group substances. By absorption, from the sera of catfish injected with group O saliva anti-H has been fractionated which differs from anti-H lectin (Ulex europeus) in its cross reactions with gibbon red cells. From the serums of the catfish immunized with group A saliva, besides anti-Z and anti-H, anti-A, but not anti-C, could be fractionated. No anti-A1 component could be fractionated by absorption with A2 cells. From the serums of catfish immunized with group B saliva, the expected anti-B together with weak anti-C could be fractionated by absorption, besides anti-Z and anti-H. These findings throw further light on the serological specificities of the human A-B-H substances of red cells and secretions and illustrate the usefulness of fish as experimental animals for serological investigations.

SummaryEight Schick negative pregnant women were given repeated injections of fluid diphtheria toxoid during pregnancy to stimulate formation of reaginic antibodies as judged by IWR. Although this occurred in most cases, it was not mirrored in the cord bloods of the corresponding infants which were examined for reagins at term. In addition, the skin of all infants was unreactive in the presence of intradermal toxoid. On the other hand, IWR were elicited in these infants and their mothers when they served as recipients for passive transfer (P.K.) tests using reaginic antibodies derived from an alternate source.