Earl H. Fife

Fluorescent-antibody technic for serodiagnosis of Trypanosoma cruzi infection.

Summary A fluorescent-antibody technic for serodiagnosis of American trypanosomiasis is presented. While nonspecific staining regularly occurs in tests using dried smears of trypanosomes, specificity is excellent when reactions are conducted in test tubes and drying of organisms is prevented. Serologic findings indicate the fluorescent-antibody procedure, used either independently or in conjunction with the complement fixation reaction, can play an important role in serodiagnosis of T. cruzi infection. An improved method for purifying antibody prior to conjugation with fluorescein also is given. Advantages of purification by isoelectric precipitation with dilute HCl over ammonium sulfate as a precipitant are noted.

Burkitt's lymphoma and malaria

Abstract An analysis of malarial parasitaemia, splenomegaly, antimalarial antibodies, immunoglobulin levels, and reticuloendothelial phagocytic function was undertaken in patients with Burkitts lymphoma in Uganda. The results reveal no difference between the Burkitt patients and controls, with the exception of lower IgM levels among the lymphoma patients. This study provides partial support for the epidemiological evidence incriminating malaria as a co-factor in the aetiology of Burkitts lymphoma.

SEROLOGICAL CHARACTERISTICS AND GENERAL CHEMICAL NATURE OF THE IN VITRO EXOANTIGENS OF T. CRUZI.

Serologic, immunologic, and chemical properties of substances produced during in vitro cultivation of Trypanosoma cruzi were investigated. After cultivation of the organisms, the medium contained an antigen which fixed complement in the presence of homologous antisera and produced detectable circulating antibody when injected into experimental animals. Different serologic patterns were observed in an evaluation of the antigen in parallel complement fixation tests using standard somatic antigens as reference. Chemical analyses of the product indicate that it is a complex substance, possibly a glycoprotein. The findings suggest that exoantigen produced during culture of the organism differs from previously described somatic antigens. Complement fixation tests are the methods of choice for serodiagnosis of Trypanosoma cruzi infection, particularly in cases of chronic infection (Pifano, 1960; Maekelt, 1960). However, the crude somatic antigens of T. cruzi used in the CF tests have been shown to lack specificity (Kelser, 1936; Liem and van Thiel, 1941; Romana and Gil, 1946; Chaffee et al., 1956). Treatment of somatic antigen with benzene and chloroform (de Freitas and Almeida, 1949) increased specificity but resulted in a loss of sensitivity. Recently, Fife and Kent (1960) prepared a purified protein antigen which gave excellent results in diagnostic tests, virtually eliminating cross reactivity except with sera from patients with mucocutaneous leishmaniasis. Development of feasible methods for mass cultivation of T. cruzi within cellulose sacs (Fife and Kent, 1960) made possible studies of an alternative, and previously unexplored T. cruzi antigen source, namely the exoantigens which might be produced during the in vitro cultivation of the parasite. Antigens liberated by parasites maintained in media have been Received for publication 7 August 1964. * From work done by the senior author in partial fulfillment of the M.S. degree at Howard University, Washington, D. C. t This work was presented, in part, at the 1st International Congress of Parasitology, Rome, 21-26 September 1964. previously studied (Sadun and Norman, 1957; Minning et al., 1958; Kagan and OliverGonzalez, 1958; Anderson et al., 1962; Sleeman et al., 1963). In addition, limited chemical analyses of similar products have been performed (Stirewalt, 1959; Stirewalt, 1963; Sleeman et al., 1963). In general, the investigations indicate that the antigenic materials liberated by organisms maintained in vitro are less complex than the somatic antigens, and that similar products liberated in vivo may play an important role in the immunogenic response of the host. The present study was conducted to dedermine whether detectable antigenic substances were produced by T. cruzi during in vitro cultivation and, if so, to study their serologic characteristics and general chemical

A New Method for Isolation and Fractionation of Complement Fixing Antigens from Plasmodium knowlesi.

Summary A new method is presented for nonchemical isolation and fractionation of the malaria parasite Plasmodium knowlesi. Since the mechanical fragility of erythrocytes is considerably greater than that of the Plasmodia, it was possible to preferentially fragment the red cell membrane without apparent alteration of the parasites. This was achieved by utilizing the precisely controlled conditions obtained with a French pressure cell operated at 1500-2000 psi. Parasites isolated by this method were subsequently fragmented at higher pressures (20,000 psi) and the solubil-ized substances fractionated by gel filtration. Fractions showing the major complement fixing activity reacted strongly with P. knowlesi antisera, were colorless, exhibited no anticomplementary properties and showed no serologic evidence of red cell contaminants. The findings indicate that the method may provide essential material for further studies on plasmodial composition and be of particular value for isolation of other intra-erythro-cytic parasites.

Effect of pH on human complement activity.

WHILE investigating the effect of acetylsalicylic acid (aspirin) on complement (C′) activity, it was observed that incorporation of 40 mg per cent of the drug in a well-buffered reagent diluent, 0.15 M triethanolamine buffered salt (TBS) solution1, significantly increased the haemolytic activity of human complement (HuC′)2. Since it was also noted that the drug slightly reduced the pH of the reaction mixture, the studies were extended to investigate the effect of pH. change on HuC′ activity.

Serum immunoglobulin D and malaria antibodies in South Vietnamese residents

Abstract Serum immunoglobulin D concentrations were found to be elevated in Vietnamese and Montagnard but not in Cambodian residents of a Vietnam village which is highly endemic for malaria. Although a high frequency of positive malaria CF tests was demonstrated in all three groups, there was no significant correlation between the serum IgD levels and the malaria CF titres. Serum IgD levels in Vietnamese residents of a non-malarious community were similar to those of United States blood donors, however, in the former groups, a high frequency (i.e., 90%) of low titre CF reactions was observed, compared to a frequency of 8% low titre CF reactions in the U.S. donors.

Tissue Antibody and Complement Levels in Runt Disease

Summary Complement fixation tests with liver and spleen antigens derived from various animal species showed no increase of circulating tissue antibody levels in rats suffering from runt disease. Complement levels, on the other hand, were markedly decreased and degree of reduction appeared to be related to severity of the disorder.

The Serodiagnosis of Early Syphilis How to Utilize the Newer Laboratory Tests

B. J. Fogel, M.D., Captain, M.C., Department of Serology, Assistant Chief, Pediatric Service, Walter Reed Army Hospital; R. W. Sanders, Microbiologist, Department of Serology; E. H. Fife, Jr., M.S., Assistant Chief, Department of Serology; R. I. Anderson, Ph.D., Lt. Col., M.S.C., Chief, Department of Serology. IE proven susceptibility of Treponema pallidum to penicillin therapy and the sharp decline in reported cases of syphilis following World War II gave rise in the last decade to the general belief that the disease might