ABSTRACT
In 131 adults and 107 aging healthy subjects of both sexes, the percentage of the T lymphocytes in peripheral blood and the cytotoxic activities of NK and K cells, were determined. No age-related differences have been found in the number of peripheral blood lymphocytes, the binding of NK cells to the K562 targets, the percentage of E rosette forming cells and the ADCC level. An increased proportion of T suppressor lymphocytes in elderly subjects and a large inter- and intra-individual variation of NK cells activity in both adult and aged subjects were found.
Subject(s)
Aging , Antibody-Dependent Cell Cytotoxicity , Cytotoxicity, Immunologic , Rosette Formation , T-Lymphocytes/immunology , Adult , Aged , Female , Humans , Killer Cells, Natural/immunology , Male , Middle AgedABSTRACT
A number of 700 guinea pigs were immunized by parenteral route with non-toxigenic Corynebacterium diphtheriae strains, then inoculated with various doses of homologous and heterologous toxigenic C. diphitheriae strains. The results showed that non-toxigenic C. diphtheriae strains confer a certain degree of protection when the challenge is done with homologous toxigenous strains, especially when not more than 500 million germs/ml are used for the challenge dose. This suggests that the carriage of non-toxigenic diphtheriae bacilli is a useful phenomenon for maintaining an immune balance in diphtheria in the present epidemiological context, and that their sterilization is not opportune.
Subject(s)
Carrier State/immunology , Diphtheria/immunology , Vaccination , Animals , Antigens, Bacterial/isolation & purification , Bacterial Vaccines , Corynebacterium diphtheriae , MiceSubject(s)
Bacteriophages , Corynebacterium/isolation & purification , Animals , Bacteriophages/classification , Bacteriophages/isolation & purification , Corynebacterium Infections/microbiology , Corynebacterium diphtheriae/isolation & purification , Corynebacterium pyogenes/isolation & purification , Humans , In Vitro TechniquesABSTRACT
A study of diphtheria in Iran was undertaken during the summer of 1969. Diphtheria was found to be more common among the younger people and to reach its peak 3 months after the start of the school term, during the coldest period of the year. Owing to the liberal use of antibiotics a number of modified clinical cases were observed. Of the strains isolated, 89.7% were gravis, 1.3% intermedius and 9% mitis. Phage typing of these strains showed that the mitis and intermedius strains could only be typed by adapted phages and the majority of gravis strains were phage type XIV, which is the epidemic type seen in other countries.As the mass immunization campaign reduces the incidence of diphtheria in Iran, the epidemiological pattern of the disease will change as seen in the U.K. and U.S.A. It is, therefore, suggested that in the future further studies of diphtheria in Iran be undertaken in order to provide us with information about the changing epidemiological pattern of the disease.