J. M. A. Wilton

DOUBLE BLIND CROSSOVER TRIAL OF LEVAMISOLE IN RECURRENT APHTHOUS ULCERATION

A double blind crossover trial of levamisole has been carried out in 47 patients with recurrent oral ulceration. Significant decreases in the number of ulcers and ulcer days were found after 2 months of intermittent administration of levamisole. About 64% of patients responded to the drug by a decrease in the number of ulcers of more than 50%, for two or more months. The remaining 36% of patients failed to respond to levamisole and 23% of these had an increased number of ulcers. The side-effects recorded in patients taking levamisole were comparable with those in patients on placebo, except for a flu-like syndrome in 1 patient and urticaria in another, necessitating withdrawal of the drug. The mechanism of action of levamisole in recurrent oral ulceration is not known, but it is suggested that levamisole may correct a deficiency of suppressor cells, or potentiate the cellular responses to crossreacting microbial agents.

Serum antibodies in dental caries in man

Abstract Serum haemagglutinating antibodies to 9 strains of streptococci and 2 of lactobacilli were determined in 47 subjects. These were divided into a group with a high D.M.F. index (mean 16) and another with a low D.M.F. (mean 3). Haemagglutinating antibodies were detected to all bacteria tested and in most sera from subjects with a high and low caries experience. Antibody levels to Streptococci FA-1 and KIR, cariogenic to animals, and an oral strain of Lactobacillus acidophilus were significantly raised in subjects with a high D.M.F., as compared with those having a low D.M.F. index. The cumulative antibody titre to 7 streptococci, cariogenic to animals, was significantly raised in subjects with a high caries incidence. These immunological results are consistent with the established view of a bacterial pathogenesis of dental caries in man.

ISOLATION OF RUBELLA VIRUS FROM SYNOVIAL FLUID IN FIVE CASES OF SERONEGATIVE ARTHRITIS

A cytopathic agent indistinguishable from rubella virus was isolated from the synovial fluid of five patients (two male and three female). In two patients isolations were made on two separate occasions, and in two others on five separate occasions. The patients ranged in age from 9-58 years, and they presented with a variety of clinical syndromes. In particular, none had clinical features suggestive of recent rubella infection; but most cases had very high serum rubella haemagglutination inhibition titres. The identity of the cytopathic agent was shown by a variety of virological techniques to be rubella virus.

Immunopotentiation by dental microbial plaque and its relationship to oral disease in man

Abstract The relationship between cell-mediated immunity and past caries experience, as well as experimental gingivitis, was investigated under the immunopotentiating conditions of dental plaque which had been allowed to accumulate for 28 days. The lymphoproliferative responses induced by Streptococcus mutans, plaque, Veillonella alcalescens and Actinomyces viscosus showed negative correlations with the DMF index, but positive correlations with the gingival index. No relationship with the DMF or gingival index was found with the unrelated purified protein derivative, or with the mitogen, phytohaemagglutinin. A second episode of plaque accumulation in the same subjects revealed that the lymphoproliferative response appeared earlier, was greater in magnitude and lasted longer in the second, as compared with the first plaque accumulation experiment. The results suggest that dental bacterial plaque has an immunopotentiating effect on cell-mediated immune responses to oral bacteria and facilitates recall of the immunological memory for bacterial antigens. A unified hypothesis is postulated for dental caries and gingival disease; immunopotentiation by dental microbial plaque has a protective immune effect on dental caries and a damaging, allergic effect on gingival disease.

The Relationship between Serum and Salivary Antibodies and Cell-Mediated Immunity in Oral Disease in Man

Immunity to diseases of the mouth shows considerable complexity, as the three principal immune systems, secretory and serum antibodies and cell mediated immunity, can be involved in the development and course of the diseases. Humoral and cellular immune responses to the commensal organisms, as well as to the aggregation of bacteria and their products on the tooth surface (bacterial plaque), have been studied recently. The immune responses to fungal, viral, Gram-positive and Gram-negative organisms in normal subjects, and in patients with the disease these organisms may cause, are worthy of analysis, as they may clarify the factors responsible for protection.

Passive Immunization with Antisera to Streptococcus Mutans in the Prevention of Caries in Rhesus Monkeys

1) The immunological mechanism of protection against dental caries has been investigated by passive immunization with antisera to S. mutans in the rhesus monkey. 2) Passive immunization with separated IgG, IgM and IgA from sera of immunized monkeys supports the concept that IgG, unlike IgA or IgM antibodies are protective. 3) The role of cell-mediated immunity has been explored by the use of transfer factor. This showed that protection against dental caries can be elicited by passive transfer of whole immune serum and cellular immunity, but not by cellular immunity or immune serum alone. 4) The results of active and passive immunization suggests that immuno-regulation of T and B cell interactions plays an important part in the effector mechanism of opsonization, phagocytosis and killing of S. mutans.