Levels and causes of stress among residents.

Medical and dental residents at the University of Rochester Medical Center were surveyed to measure stress and its causes. Their stress, as measured by the brief symptom inventory, showed levels slightly above those of an adult comparison group. The average levels of stress decreased with the residents' advancing levels of training. Comparison of the top quartile with the lowest quartile of scores of everyday stress showed significantly elevated stress for rotations in the emergency room, greater frequency of being on call, and lesser amount of sleep. The residents' reports showed that the bleakest three days of residency tended to occur in the first year and during intensive care rotations. Stress during these bleakest times was significantly higher than everyday levels. The residents described the major causes of distress during bleakest times as lack of sleep, inadequate support from senior professionals, large patient load, and competition from peers. "High quality" teaching rounds, a night-float system, and sick leave were felt by the residents to lessen stress. To cope with the stress, the residents reported they talked to others, tried to see humor in the situation, or slept.

Use of combined immunization routes in induction of a salivary immunoglobulin A response to Streptococcus mutans in Macaca fascicularis monkeys.

Various combinations of immunization routes were examined for ability to elicit or prolong (or both) a salivary secretory immunoglobulin A response to Streptococcus mutans strain Ingbritt (serotype c) in Macaca fascicularis monkeys. Intraductal (i.d.), per os (p.o.), and subcutaneous (s.c.) routes were utilized. Four groups of three to five monkeys each were immunized by the following schedules: group I--p.o., s.c., i.d.; group II--i.d., p.o., i.d.; group III--s.c., p.o., i.d.; and group IV--control. Immune responses in the serum and parotid fluid were quantitated by using passive hemagglutination assays with purified serotype-specific polysaccharide and by indirect immunofluorescent staining assays. Both s.c. and i.d., but not p.o., routes resulted in detectable serum antibody responses. Only i.d. immunization resulted in a measurable salivary response. Indirect immunofluorescent staining revealed specific secretory immunoglobulin A antibodies in the parotid fluid which correlated with passive hemagglutination titers. The p.o. procedures used in this study did not result either in a prolonged immune response or in measurable tolerance related to the humoral or secretory immune system.

Mucosal graft vestibuloplasty over a xenograft: report of case.

A case is described that demonstrates the use of DDBB to eliminate an anterior undercut in the augmentation in the edentulous mandible. Subsequent vestibular extension using a free mucosal graft was performed superficially to the xenograft bed. This material is extremely useful because it is biologically bonded to underlying bone and is not jeopardized by a second surgical procedure in the graft region.

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 Freund's 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.

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.

Prevention of Streptococcus mutans infection of tooth surfaces by salivary antibody in Irus monkeys (Macaca fascicularis).

Four irus monkeys (Macaca fascicularis) were immunized with Streptococcus mutans 6715 killed cells and cell products by injection in the vicinity of the major salivary glands and by instillation into the parotid glands via the ducts. After immune group and a sham-immunized control group of monkeys were infected orally with viable strain 6715 organisms. Dental plaque samples were taken at intervals from the buccal and lingual grooves of the first permanent molars. These samples were evaluated for recovery of strain 6715 by cultural methods. In addition, individual samples were taken from 10 representative tooth surfaces and were evaluated by indirect immunofluorescent staining for strain 6715. Results showed that immune monkeys had fewer infected surfaces and fewer organisms on the infected surfaces than the control animals. These studies indicate that salivary antibody to cariogenic streptococci inhibits implantation of these organisms in dental plaque and may be protective against dental caries.

Antibody response in the parotid fluid and serum of Irus monkeys (Macaca fascicularis) after local immunization with Streptococcus mutans.

The antibody response of Macaca fascicularis in parotid saliva and serum to local immunization by two routes with Streptococcus mutans was studied and compared over 1 year. Antibodies were titrated and classified by indirect immunofluorescent staining using specific antiglobulin conjugates. Antiglucosyltransferase activity was assayed by an enzyme inhibition test. Animals were immunized first by injecting formalin-killed bacterial cells and cell products subcutaneously into the vicinity of the four major salivary glands. The monkeys were next immunized by retrograde instillation of antigen into the parotid duct. Extensive subcutaneous local immunization gave a serum response only. After parotid duct immunization, high titers of immunoglobulin A (IgA) antibody, along with traces of immunoglobulin G (IgG) immunoglobulin M (IgM) antibody, appeared in the parotid saliva, and in the serum high titers of IgG antibody were present along with lower titers of IgA and IgM. IgA antibodies in parotid fluid were shown by double immunofluorescent staining to be associated with antigenic determinants which cross-reacted with an antiserum directed to human secretory component. Titers in parotid fluids and sera fell sharply when immunization was stopped. This response pattern was reproducible. High concentrations of antibody capable of inhibiting glucosyltransferase prepared from S. mutans were found in the sera, but relatively little was detected in the parotid fluids. Extensive immunization via the parotid duct resulted in transient functional impairment of the gland, as evidenced by diminished salivary flow rates. We conclude that parotid ductal immunization can be an effective method for stimulating a salivary secretory IgA antibacterial antibody response.