Biomedical subjects

James S Hodges

Publications and source records attributed to James S Hodges.

At least 19 recordsLinked to original sources

PubMed2006

No association between selected candidate gene polymorphisms and severe chronic periodontitis.

BACKGROUND: Chronic periodontitis (CP) risk is influenced by environmental and genetic factors. Using a case-control design, we tested for associations between CP and selected DNA sequence variations (single nucleotide polymorphisms [SNPs]) in or near genes coding for proteins that play a role in the pathogenesis of this disease. METHODS: DNA was analyzed from 219 whites who were examined clinically. Cases (N=137) were >or=35 years of age with eight or more teeth having >or=5 mm of proximal clinical attachment loss. Controls (N=82) were >or=45 years of age with minimal or no proximal attachment loss or pocketing. Nine diallelic polymorphisms (gene and SNP descriptor) were studied in subjects: cytotoxic T-lymphocyte antigen-4 (CTLA-4, 49 A>G), human beta-defensin-1 (DEFB1, 692 G>A), intercellular adhesion molecule-1 (ICAM-1, 1548 A>G), Fas ligand (fasL, -844 C>T), inducible costimulator (ICOS, 3990 G>T), interleukin-6 (IL-6, -174 G>C), cysteine-cysteine chemokine receptor-5 (CCR5, 59653 C>T), osteoprotegerin (OPG, 245 T>G), and osteopontin (OPN, 707 C>T). Genotypes were determined using an automated fluorogenic 5'-nuclease, polymerase chain reaction-based assay. Gender and smoking history (pack-years) were included as covariates in logistic regression analyses. RESULTS: Heavy smoking (>10 pack-years) and male gender were significantly associated with disease (P<0.001). For all SNPs tested, the allele frequencies and distributions of genotypes did not differ between cases and controls (P>0.05). No unadjusted or adjusted odds ratios (comparing genotypes in cases versus controls) were significantly different than 1.0 (P>0.05) under any additive, dominant, or recessive inheritance model. CONCLUSIONS: None of the SNPs tested were strongly associated with generalized severe chronic periodontitis in North American whites. A potentially more fruitful approach in future studies will be to test for associations between periodontitis and haplotype blocks constructed from either multiple SNPs in candidate gene regions or from panels of markers that span the entire genome.

Adult↗

PubMed2006

The influence of dynamic occlusal interferences on probing depth and attachment level: results of the Study of Health in Pomerania (SHIP).

BACKGROUND: The purpose of this study was to investigate potential associations between dynamic occlusal interferences and signs of periodontal disease in posterior teeth based on dental and medical measurements obtained from a population-based sample in the cross-sectional epidemiological study entitled, "Study of Health in Pomerania" (SHIP). METHODS: Medical history and dental and sociodemographic parameters of 2,980 representatively selected dentate subjects, 20 to 79 years of age, were collected. The analysis was performed on posterior teeth only using a mixed linear model that considers the clustered structure of the data. The model also was adjusted with respect to known risk factors for periodontal disease. RESULTS: The presence of non-working side contacts only was significantly related to probing depth (P<0.0001) and attachment loss (P=0.001). The presence of non-working side contacts and working side contacts on the same tooth was significantly related to increased probing depth (P=0.004) but not attachment level. The effect magnitude was a mean increase of 0.13 mm for probing depth and 0.14 mm in attachment loss. Known risk factors for periodontal disease that also showed significant associations with probing depth and attachment loss included male gender, age, smoking, education, and plaque score. Other factors significantly related to probing depth and/or attachment loss were tilted teeth, restored occlusal surfaces versus sound surfaces, elongated teeth, and tooth type (molar versus premolar). CONCLUSION: The effect of non-working contacts on periodontal disease status was discernible, but weak in terms of magnitude and specificity.

Adult↗

PubMed2006

Clinical evaluation of a resin-modified glass-ionomer liner for cervical dentin hypersensitivity treatment.

PURPOSE: To evaluate the effectiveness of two agents for treating cervical dentin sensitivity associated with gingival recession or noncarious cervical lesions. METHODS: 44 patients with at least mild sensitivity affecting cervical dentin were enrolled in a longitudinal randomized clinical trial. A resin-based desensitizer or an experimental glass-ionomer was assigned to treat at most two teeth from each side of the mouth. Sensitivity was assessed by tactile and cold tests, measured with a Visual Analogue Scale at baseline, after treatment, and at 1 week, 1, 3, 6, and 12 months after treatment. Other noteworthy clinical observations were recorded. RESULTS: Both treatments effectively reduced dentin sensitivity (mixed linear model analysis). Sensitivity score for the glass-ionomer was significantly lower than for the resin-based desensitizer after treatment and at all follow-up periods (P < 0.0001). Some overhanging margins were observed in the glass-ionomer group, which could accumulate plaque and cause gingivitis. Despite material loss from some teeth treated with the glass-ionomer, the follow-up sensitivity scores were still lower than baseline scores.

Adult↗

PubMed2005

Generalized spatial structural equation models.

It is common in public health research to have high-dimensional, multivariate, spatially referenced data representing summaries of geographic regions. Often, it is desirable to examine relationships among these variables both within and across regions. An existing modeling technique called spatial factor analysis has been used and assumes that a common spatial factor underlies all the variables and causes them to be related to one another. An extension of this technique considers that there may be more than one underlying factor, and that relationships among the underlying latent variables are of primary interest. However, due to the complicated nature of the covariance structure of this type of data, existing methods are not satisfactory. We thus propose a generalized spatial structural equation model. In the first level of the model, we assume that the observed variables are related to particular underlying factors. In the second level of the model, we use the structural equation method to model the relationship among the underlying factors and use parametric spatial distributions on the covariance structure of the underlying factors. We apply the model to county-level cancer mortality and census summary data for Minnesota, including socioeconomic status and access to public utilities.

Bayes Theorem↗

PubMed2005

The surface free energy of dental gold-based materials.

OBJECTIVE: A gold composite material (Captek) has been developed which is claimed to resist plaque deposition. This study's aim was to compare the surface free energy (SFE) of this composite material with that of a type III casting gold. METHODS: Contact angle measurements, using the Wilhelmy technique, were made on four bar-shaped samples of each material, using five test liquids (diiodomethane, ethylene glycol, formamide, glycerol and water) and four measurements per sample per liquid. For each material, the dispersive, Lewis acid and Lewis base components of SFE (gamma(S)D, gamma(S)+, gamma(S)-, respectively) were estimated by least squares analysis and also by a Bayesian method. RESULTS: The gold composite material and the type III casting gold did not differ significantly in their gamma(S)D values (95% confidence interval for gold composite minus type III gold, -5.0 to +2.7). Both materials had low gamma(S)+ values in common with most solids. The gold composite had a significantly lower Lewis base component of SFE than the type III gold-8.4 mN/m for the former material compared to 19.1 mN/m for the latter (95% confidence interval for gold composite minus type III gold, -16.4 to -4.9). The difference between materials could be related to the lack of non-precious metals and the structure of the gold composite material. CONCLUSIONS: It is hypothesized that difference in gamma(S)- components of SFE may be an important parameter in predicting bacterial adhesion and plaque resistance. Methods that only determine SFE as a single parameter may be unable to differentiate adequately between dental restorative materials.

Bayes Theorem↗

PubMed2005

The wetting of surface-treated silicone impression materials by gypsum mixes containing disinfectants and modifiers.

PURPOSE: This work evaluated wettability of silicone impression surfaces by gypsum mixes containing disinfectants. MATERIALS AND METHODS: Two types of dental stone were modified by mixing with aqueous solutions of either sodium hypochlorite or povidone iodine. These materials were subjected to further modification by adding a mixture of 1% gum arabic and 0.132% calcium hydroxide to reduce the water requirement of the hemihydrate. Mix consistency tests were carried out to determine the effect of the disinfectants and the modifying additives on the mix fluidity. Contact angles of the mixed materials were measured when they were poured against a polyvinylsiloxane impression material that had undergone the following treatments (1) no treatment (control), (2) surfactant treated, (3) disinfectant treated, and (4) treated with both surfactant and disinfectant. One-way analysis of variance (ANOVA) was carried out using Dunnett's method to determine if experimental groups were significantly different from the control. RESULTS: Gypsum mix consistency was reduced by the presence of combined gum arabic and calcium hydroxide additives. Contact angle data showed that the additives and disinfectants incorporated into the gypsum had, in general, no beneficial effect on the wetting of an untreated silicone surface, or a surface treated with surfactant. In some instances, better wetting was obtained with disinfectant-treated surfaces, and surfaces that had been disinfected and treated with surfactant. CONCLUSIONS: Fluidity of the mixed gypsum was affected by the modifying additives. Chemical disinfectants incorporated in gypsum have little effect on the wetting behavior of dental gypsum. Modifying dental stone powders with gum arabic and calcium hydroxide additives (before mixing at the manufacturers' recommended liquid/powder ratios), improved the wetting behavior of the mixed materials in some cases, but results were not consistent.

Analysis of Variance↗

PubMed2005

Self-reported toothache experience in an adult population in Benin City, Edo State, Nigeria.

PURPOSE: This pilot study was conducted to estimate the prevalence of self-reported toothache, bleeding gums and oral ulcer experiences, reasons for dental visits and associated sociodemographic factors among adults living in Benin City, Edo State, Nigeria. MATERIALS AND METHODS: This cross-sectional study was based on a convenience sample in an urban setting. Out of the 540 persons surveyed, 508 had complete usable information, 48% males and 52% females, and aged 18 - 54 years. A closed questionnaire was used to collect the data at two large medical outpatient facilities and a university community. RESULTS: The proportion reporting toothache experience in the previous 12 months was 34%; painful/ bleeding gums 28%, and oral ulcers/painful spots 14%. Univariate analysis showed that toothache experience was associated with time since last dental visit (p < 0.001), age (p < 0.001), gender (p < 0.001) and education (p < 0.001). Experience with bleeding gums was associated with gender (p < 0.001), education (p < 0.001) and last dental visits (p < 0.001). Oral ulcers were associated with gender (p = 0.004), age (p < 0.001) and last dental visits (p < 0.001). Fewer males than females reported toothache (25% vs. 42%, OR 1.65) but more males reported bleeding gums (37% vs. 19%, OR = 0.34) and oral ulcers (19% vs. 10% OR = 0.33). CONCLUSIONS: Toothache experience was the most prevalent oral health problem reported by adults. Oral health problems were associated with age, gender and last dental visits.

Adolescent↗

PubMed2004

A protocol for determining the surface free energy of dental materials.

OBJECTIVE: The purpose of this study was to develop a standard methodology for measuring the surface free energy (SFE), and its component parts, of dental biomaterials. METHODS: The contact angle of each of four samples of two materials--low density polyethylene and poly(methyl methacrylate)--was measured three times in each of six liquids (1-bromonaphthalene, diiodomethane, ethylene glycol, formamide, glycerol and distilled water). Critical surface tension estimates were obtained from Zisman plots. Data were then analyzed by the least-squares method to estimate the components of SFE. Estimates were also made for each of 12 liquid triplets, and by maximum likelihood and Bayesian analyses. RESULTS: The use of liquid triplets could yield misleading estimates of the components of SFE. A testing protocol is suggested in which multiple test liquids are used, and multiple methods of statistical analyses employed. SIGNIFICANCE: SFE is important, in that high SFE is desirable when adhesion is required, but undesirable if plaque resistance is needed. Methodology that avoids some of the limitations of existing studies has been proposed.

Bayes Theorem↗

PubMed2004

The association of periodontal disease parameters with systemic medical conditions and tobacco use.

OBJECTIVES: The objective of this study was to determine if an association existed between periodontal disease and various systemic medical conditions and tobacco use. MATERIAL AND METHODS: The study design was a case-controlled, retrospective chart review. Patient charts (n=2006) were selected from more than 13,000 active patients attending the University of Minnesota dental clinics. These charts were examined to determine patient's self-reported systemic condition and smoking history. In addition, the number of missing teeth and bone loss were recorded. Two examiners collected the data. One examiner abstracted patient's medical history from the standard clinic medical questionnaire. The second examiner assessed the radiographs and dental charts to determine bone loss and number of missing teeth. Each examiner was blind to the findings of the other. RESULTS: After adjusting for age, sex, diabetes and smoking (yes/no) status, seven conditions were significantly (p=0.0003-0.04) related to bone loss or number of missing teeth (vascular disease, heart surgery, vascular surgery, heart attack, thyroid problems, arthritis, stomach ulcers). From these conditions, thyroid problems and arthritis had a negative association with bone loss. CONCLUSIONS: These findings support the results from previous investigators that a number of systemic conditions and smoking are closely associated with missing teeth or bone loss.

Aged↗

PubMed2003

SYM 2081, an agonist that desensitizes kainate receptors, attenuates capsaicin and inflammatory hyperalgesia.

Excitatory amino acids acting at non-NMDA receptors contribute to transmission of nociceptive information. SYM 2081 ((2S,4R)-4-methyl glutamic acid) desensitizes kainate receptors, one subtype of non-NMDA receptors, to subsequent release of excitatory amino acids and thus may attenuate transmission of nociceptive information. To determine if SYM 2081 can prevent development of hyperalgesia, SYM 2081 (10, 50 or 100 mg/kg, i.p.) was administered prior to injection of capsaicin into the hindpaw of rats, which produces mechanical and heat hyperalgesia. To determine if SYM 2081 can reduce ongoing inflammatory hyperalgesia, SYM 2081 (10 or 100 mg/kg, i.p.) was administered after development of carrageenan-evoked hyperalgesia. Intraplantar injection of capsaicin produced an increase in hindpaw withdrawal frequency to mechanical stimuli (from 4+/-2 to 41+/-7%; mean+/-S.E.M.) and a decrease in withdrawal latency to heat (from 12.3+/-0.3 to 5.9+/-0.4 s) in rats that received vehicle. In contrast, rats that received SYM 2081 (100 mg/kg) prior to injection of capsaicin exhibited a lower hindpaw withdrawal frequency (18+/-4%) and a longer withdrawal latency (7.7+/-0.5 s). Intrathecal (1-100 microg/5 microl), but not intraplantar (10 or 100 microg/50 microl), injection of SYM 2081 attenuated the development of capsaicin-evoked heat hyperalgesia suggesting that SYM 2081's antihyperalgesic effects were due to its central effects. Furthermore, SYM 2081 completely reversed ongoing carrageenan-evoked mechanical hyperalgesia and partially (approximately 50%) reversed ongoing heat hyperalgesia. The present study demonstrates that administration of a high-potency ligand that selectively desensitizes kainate receptors attenuates the development of mechanical and heat hyperalgesia and attenuates ongoing inflammatory hyperalgesia.

Animals↗

PubMed2003

The modulation of tissue factor by endothelial cells during heat shock.

Tissue factor (TF) initiates the extrinsic coagulation cascade on the surface of macrophages and endothelial cells. In septic patients, the extrinsic coagulation cascade is activated. When septic patients are febrile, mortality is decreased. The purpose of this study was to investigate the role of elevated temperatures on TF expression by endothelial cells during a sepsis-like challenge. Human endothelial vein cells (HUVECs) were incubated with lipopolysaccharide (LPS) or interleukin-1 beta (IL-1 beta) for 0, 2, 4, 6, or 8 h. At the 0-h time point, some HUVECs were heat shocked at 43 degrees C for 2 h and then recovered at 37 degrees C for 0, 2, 4, or 6 h. Heat-shocked and non-heat-shocked LPS-stimulated HUVECs were analyzed for TF-specific mRNA expression by ribonuclease protection assay (RPA), surface TF expression by flow cytometry, and TF activity by a two-stage clotting assay. Heat shocked LPS-stimulated HUVECs expressed significantly reduced TF-specific mRNA, TF surface protein levels, and TF surface activity when compared with non-heat-shocked, LPS-stimulated HUVECs (p < 0.0125, p < 0.0125, and p < 0.0001, respectively; repeated measures analysis of variance, ANOVA). If heat shock models elevated core temperature, these results suggest that fever may protect the host during sepsis by reducing TF activity on the surface of endothelial cells.

Base Sequence↗

PubMed2003

Clinical evaluation of resilient denture liners. Part 2: Candida count and speciation.

PURPOSE: The purpose of this study was to count and to speciate Candida isolated from 2 resilient denture liners, Molloplast-B and MPDS-SL. MATERIALS AND METHODS: A group of 20 patients each had 1 maxillary denture and 2 mandibular dentures fabricated. One mandibular denture was lined with Molloplast-B, and 1 was lined with MPDS-SL. Each denture was used for 3 months. At the end of the 3-month period, the mandibular denture was surrendered, and a 5 x 5-mm circular resilient liner sample was obtained from the tissue surface of the lingual flange. Samples were processed, and Candida was isolated and counted. Speciation of Candida was performed using CHROMagar Candida and API 20C AUX strips. RESULTS: Molloplast-B had, on average, 5 times as many CFU/sample as MPDSL-SL, but this difference was not significant (p = 0.26). A sign test gave a similar nonsignificant trend (p = 0.057). CHROMagar identified several Candida species, and confirmation was made using API 20C AUX strips. One patient was lost to follow-up. Of 19 Molloplast-B samples, 7 had no growth, 4 grew C. albicans, 3 grew C. parapsilosis, 2 grew C. glabrata, 1 grew C. tropicalis, 2 grew a Trichosporon spp., and 2 grew a nonidentifiable colony. The analogous counts for 19 MPDS-SL samples were 10, 4, 1, 3, 0, 1, and 1 (p = 0.45 for culture positively, exact McNemar test). CONCLUSIONS: Candida growth on Molloplast-B was not significantly different from growth on MPDS-SL. Several yeast species were cultured from each material. The rates of culture-positive testing did not differ between the 2 resilient denture liners.

Adult↗

PubMed2003

Clinical evaluation of a new resilient denture liner. Part 1: Compliance and color evaluation.

PURPOSE: A new experimental resilient denture liner (MPDS-SL; Lai Laboratories, Burnsville, MN) and Molloplast-B (Buffalo Dental Manufacturing, Syosset, NY) were clinically evaluated for compliance and color change over a 1-year period. MATERIALS AND METHODS: In this crossover study, each of 20 patients had 2 dentures fabricated with long-term, silicone-based resilient liners, 1 denture with Molloplast-B and the other with MPDS-SL. Each denture was used for 6 months, during which time each patient kept a journal detailing his or her use and cleaning regimen. The 2 materials were assessed for compliance and color at the beginning of the study and again after 3 months and 6 months of use. Compliance was determined by applying a 3-lb force to the surface of the material following a square-wave pattern, using a closed-loop servohydraulic testing system. The force and position values were recorded using a storage oscilloscope. Compliance was measured at 3 locations on each denture and analyzed using data-acquisition software. Images of the dentures were captured using a zoom stereomicroscope with a charge-coupled video camera and image analysis software. The color was measured at 3 locations on each denture; RGB and L* a* b* were calculated. RESULTS: Compliance increased from baseline to 3 months and from 3 months to 6 months for almost all locations on both materials. Molloplast-B and MPDS-SL differed in average change in compliance at 6 months; the average change in compliance from baseline to 6 months was 453 (standard error, 46) for Molloplast-B and 284 (standard error, 46) for MPDS-SL (p = 0.019). For both materials, color changed significantly from baseline to 3 months and from baseline to 6 months (p < 0.01). MPDS-SL changed significantly less than Molloplast-B from baseline to 6 months for R (p = 0.039), G (p = 0.037), B (p = 0.005), and L* (p = 0.042). CONCLUSION: For both materials, compliance increased over 6 months of wear. The color change for MPDS-SL was considerably less significant than that for Molloplast-B.

Aged↗

PubMed2003

On the precision of the conditionally autoregressive prior in spatial models.

Bayesian analyses of spatial data often use a conditionally autoregressive (CAR) prior, which can be written as the kernel of an improper density that depends on a precision parameter tau that is typically unknown. To include tau in the Bayesian analysis, the kernel must be multiplied by tau(k) for some k. This article rigorously derives k = (n - I)/2 for the L2 norm CAR prior (also called a Gaussian Markov random field model) and k = n - I for the L1 norm CAR prior, where n is the number of regions and I the number of "islands" (disconnected groups of regions) in the spatial map. Since I = 1 for a spatial structure defining a connected graph, this supports Knorr-Held's (2002, in Highly Structured Stochastic Systems, 260-264) suggestion that k = (n - 1)/2 in the L2 norm case, instead of the more common k = n/2. We illustrate the practical significance of our results using a periodontal example.

Bayes Theorem↗

PubMed2003

Total-etch versus self-etch adhesive: effect on postoperative sensitivity.

BACKGROUND: Self-etching adhesives are believed to prevent postoperative sensitivity when used under posterior resin-based composite restorations. The authors tested a twofold hypothesis: a self-etch, or SE, adhesive would result in less postoperative sensitivity than a total-etch, or TE, adhesive; an SE adhesive would result in poorer enamel marginal integrity than a TE adhesive. METHODS: Patients were selected on the basis of requiring Class I and II restorations in molars and premolars. The authors placed 30 restorations with the SE material (Clearfil SE Bond, Kuraray America, New York) and 36 restorations with Prime & Bond NT (Dentsply Caulk, Milford, Del.), which uses 34 percent phosphoric acid to etch enamel and dentin simultaneously. Preparations were of standard design, with all margins in enamel without beveling. Upon rubber dam isolation, the authors conditioned the enamel and dentin walls with the self-etching primer (for Clearfil SE Bond) or etched with the proprietary 34 percent phosphoric acid (for Prime & Bond NT), followed by application of the corresponding dentin adhesive. Teeth were restored with the proprietary hybrid resin-based composite indicated for posterior restorations: Clearfil AP-X for Clearfil SE Bond or Esthet-X Micro Matrix Restorative for Prime & Bond NT. The restored teeth were evaluated preoperatively and at two weeks, eight weeks and six months postoperatively for sensitivity to cold (ice), air and masticatory forces, as well as for marginal discoloration. RESULTS: Analysis of variance revealed no statistically significant differences in postoperative sensitivity between the SE and TE materials at any recall time. Marginal discoloration was rated as "absent" for all restorations at six months. Only one tooth displayed sensitivity to occlusal forces at six months. CONCLUSION: The SE adhesive did not differ from the TE adhesive in regard to sensitivity and marginal discoloration. CLINICAL IMPLICATIONS: Postoperative sensitivity may depend on the restorative technique rather than on the type of dentin adhesive used.

Acid Etching, Dental↗

PubMed2003

Patient perceptions of professionalism in dentistry.

The purpose of this study was to examine how patients perceived the professionalism of University of Minnesota School of Dentistry students, faculty, and staff. Professionalism is defined by the authors as an image that will promote a successful relationship with the patient. Patients within comprehensive care clinics were asked to assess physical attributes and behaviors of the dental care providers using a questionnaire. The patients read statements dealing with characteristics of the dental care providers and responded as to whether they agreed, were neutral, or disagreed with the statement. The surveyed population consisted of 103 males and 97 females, 64 percent of whom lacked insurance coverage. Fifty-one percent of the patients were between the ages of forty-four and sixty-nine, but the overall age distribution was dispersed over a range of eighteen to one hundred. Our research found that all dental care providers displayed a professional appearance as well as behavior. The attire of the dental care provider affected the comfort and anxiety levels of patients, as did first impressions of both students and faculty. Most patients reported that students and faculty displayed effective time management and used appropriate language during the appointment. Finally, hairstyle, makeup, and jewelry appeared to have little effect on patients' opinions of the various dental care providers.

Adolescent↗

PubMed2003

Bond strengths of tooth-colored posts, effect of sealer, dentin adhesive, and root region.

PURPOSE: To evaluate the effect of sealer, dentin bonding agent, and root region on the push-out bond strengths of three tooth colored posts. METHODS: 24 extracted human single rooted maxillary central incisors and canines were endodontically-treated using gutta percha and Roth's 801 or AH26 sealer. Posts (Cosmopost, Fibrekor, or Parapost Fiber White) were placed using one of two adhesive systems (Parapost Cement Conditioner with Parapost Cement, or One-Step with Hi-X Post self-cure resin cement). The push-out test was performed on different sections of the root to measure bond strengths. RESULTS: Cosmopost showed significantly lower mean bond strengths than either Fibrekor or Parapost. Bond strengths of the posts in the crown section were significantly higher than those in any of the three root areas measured. Neither the eugenol-containing sealer nor the bonding agent type had any effect on bond strength. Post type and root region significantly affected bond strength while sealer type or bonding agent had no effect on bond strength.

Analysis of Variance↗

PubMed2002

Streptococcus sanguis modulates type II collagen-induced arthritis in DBA/1J mice.

Native type II collagen is tolerogenic when given orally or i.p. to DBA/1J mice and induces autoimmune arthritis when given s.c. in CFA. The tolerogenic epitope is contained in cyanogen bromide fragment 11 (CB11) and is structurally mimicked by PGEQGPK within the platelet aggregation-associated protein (PAAP) on Streptococcus sanguis. To learn whether S. sanguis modulates transmucosally the Ag-specific development of autoimmune arthritis, DBA/1J pups were given live S. sanguis, CB11, or type II collagen intragastrically. Feeding S. sanguis at 6 days postpartum delayed the onset of arthritis, and reduced the rate, final severity, and percentage of affected limbs. Next, PAAP(+) S. sanguis and type II collagen were tested for T cell cross-reactivity. T cells primed with the tolerogenic epitope of type II collagen proliferated more when incubated with PAAP(+) S. sanguis than with PAAP(-) Streptococcus gordonii or type II collagen, suggesting an Ag-specific transmucosal tolerogenic effect. In neonatal mice, therefore, bacterial surface Ags that mimic self can transmucosally stimulate Ag-specific inhibitory T cells. In adult mice immunized with type II collagen, these Ag-specific inhibitory T cells manifest later as attenuated arthritis. The PAAP(+) S. sanguis appear to activate adult memory, rather than naive, type II collagen-specific T cells, suggesting that systemic challenge with commensal self-mimicking microorganisms may perpetuate existing autoimmunity, but not initiate autorecognition.

Administration, Oral↗