Fred G. Emmings

Cryotherapy for cancer of the lip and oral cavity

Cryotherapy with modern apparatus utilizing liquid nitrogen was used to control malignant and benign lesions of the lip and oral cavity in 5 patients. The reasons for the choice of therapy included resistance to radiotherapy, lesions in areas not amenable to excision without disabling bone sacrifice (palate, mandible) and severe cardiac disease which made the risk of operation prohibitive. Usually local anesthesia was used. One patient died of acute myocardial infarction 4 months after treatment and at autopsy no residual tumor was found in the treated area. The other patients are free of local recurrence at this time and none have palpable regional lymph nodes. Additional clinical evaluation is required but the results suggest that cryotherapy merits more extensive trial in selected patients in whom the customary methods of treatment have failed or cannot be used without great risk.

Immunization of Macaca fascicularis (Macaca irus) Monkeys with Streptococcus mutans: Specificity of Antibody Responses in Saliva

M fascicularis monkeys were immunized subcutaneously in the vicinity of the major salivary glands and by retrograde infusion into the parotid duct, with a vaccine containing Formalin-killed S mutans strain 6715 cells and culture-fluid antigens. Indirect immunofluorescent staining was used to titrate and classify antibodies. Subcutaneous immunization induced only a serum response, whereas intraductal infusion stimulated both an IgA antibody response in the parotid fluid and a serum response. Immunized and nonimmunized control groups were orally infected with S mutans strain 6715. The establishment in dental plaque was quantitated by recovery of the infecting organism on selective media and by immunofluorescent staining of plaque smears taken from individual tooth surfaces. The establishment of S mutans strain 6715 was noticeably inhibited in immune monkeys. Immunofluorescent assays for antibody also showed that serum and parotid fluid containing serum IgA antibodies cross reacted with other d serotype and a serotype strains but not representative b and c strains. Immune and control groups were then orally infected with S mutans strain GS-5, a c serotype strain, and no inhibition in establishment was detected of the non-cross-reacting type c organism in the immune group. A latter series of booster immunizations via the intraductal route resulted in a significant decrease in parotid fluid flow. Histological investigations showed inflammatory cell infiltration and replacement of epithelium by connective tissue in the glands from immunized monkeys. A separate group of monkeys, younger than the first, was immunized with the same vaccine via the duct only. In this group, immunizations were given at shorter intervals, but the immunization response was similar to that observed in the first group. The investigations reviewed here and new experiments reported show that immunization of monkeys with S mutan strain 6715 via the parotid duct elicited a reproducible IgA antibody response in the parotid fluid as well as a serum antibody response. Inhibition of colonization on tooth surfaces in immune monkeys showed specificity for the immunizing strain suggesting that inhibition was antibody mediated.

Effects of antibodies on adherence and cell-associated glucan production by Streptococcus mutans cells.

Studies reported here show that hyperimmune rabbit serums can have profound inhibitory effects on adherence of S mutans to smooth surfaces and that this reduction in adherence is correlated with the reduction of CAG. The latter was measured by an assay developed in our laboratory that estimates CAG production by measuring the uptake of 14C glucose-labeled sucrose into components which can be extracted by dilute alkali. This is a direct demonstration of the effect of antibody on a metabolic function of S mutans that is important in virulence. The direct correlation bewteen inhibition of CAG production, and inhibition of adherence by an antibody, suggests that the inhibition of adherence is brought about by reduction of CAG synthesis. Further studies reported here show that the inhibition of adherence and of CAG synthesis is much more effective in homologous antiserums as compared to heterologous antiserums. These results point to the need for in vivo experiments to test the effects of vaccines on colonization by heterologous as well as homologous S mutans strains.

The IgA Antibody-Forming Cell Response in the Rabbit Submandibular Gland Following Several Different Methods of Immunization

Secretory IgA (sIgA) is found in the saliva of humans and other animals where its principle sources are the major salivary glands. Taubman and Smith (1) showed that salivary IgA antibody, induced by vaccination with cariogenic S. mutans, was correlated with a decrease in dental caries in rats. The practical use of the secretory immune system in protection against disease in humans depends partly on a clear understanding of the mechanisms which govern the induction of a secretory immune response. There are numerous reports showing that topical application of antigen to the gastrointestinal or respiratory tracts can result in induction of sIgA antibodies (cf. reviews 11,12). It is not clear however, how best to induce sIgA antibody production in solid organs such as the salivary and lacrimal glands. In this study we systematically examined several methods of immunization designed to stimulate a secretory immune response in the salivary glands of rabbits.

Purification, Characterization, and Immunogenicity of Cell-Associated Glucan from Streptococcus mutans

Appropriate immunization with whole cell vaccines of S mutans appear to induce antibodies that inhibit implantation of S mutans on tooth surfaces and associated dental caries. To better understand the mechanisms by which vaccination prevents S mutans implantation and dental caries, and to prepare antigens whose effectiveness and safety can be tested in animal models of caries, we set out to purify and chemically characterize the CAG of S mutans. The CAG of S mutans strain 6715 was prepared by extracting cells with potasssium hydroxide at 100 C. After neutralization and extensive washing, the water-insoluble product was characterized by a battery of chemical analyses and found to be a relatively pure glucan. The CAG was weakly immunogenic in rabbits when administered in Freunds complete adjuvant. In monkeys (M irus) immunized via the parotid duct with an aqueous solution of CAG, a definite but weak serum IgG, IgM, IgA, and salivary IgA antibody response was observed. Absorption experiments showed that the CAG induced antibodies that cross reacted with Sephadex G-25 and others that reacted with unique determinants on CAG. Retention of native antigenic determinants through the purification procedures was verified by the observations that antiserums to CAG reacted with whole cells of S mutans and by the fact that antiserums to S mutans cells reacted with CAG.