Differences in the Knowledge and Experience of Physicians and Dentists About Medication-Related Osteonecrosis of the Jaw in Osteoporotic Patients.

AIM: Prevention of medication-related osteonecrosis of the jaw (MRONJ) in patients with osteoporosis requires the cooperation of physicians and dentists. We investigated the knowledge, experience, and behaviour related to medical and dental cooperation for MRONJ prevention in patients with osteoporosis between physicians and dentists practising in the Shiga prefecture. MATERIALS AND METHODS: We conducted a cross-sectional study to investigate the cooperation between practising physicians and dentists for preventing osteonecrosis of the jaw (ONJ) in patients with osteoporosis using 2 separate questionnaires from July 28, 2018, to February 3, 2019. RESULTS: Of 461 dentists who were sent the questionnaires at their dental clinics, 307 (67%) responded via fax. Of 846 physicians who were sent the questionnaire at their clinics, 378 (45%) responded via fax. Of these, 268 (32%) were finally analysed because 110 (13%) physicians had never treated patients with osteoporosis; 50% dentists and 24% physicians were familiar with the MRONJ position paper in Japan, and 39% dentists and 9% physicians had encountered MRONJ in their clinical practice. A total of 30% physicians had requested oral health care by a dentist before administering bone-modifying agents (BMA) therapy. The knowledge and experience of MRONJ differed between physicians and dentists. CONCLUSION: The behaviour of physicians and dentists was insufficient to enable medical and dental cooperation for the prevention of MRONJ in patients with osteoporosis. The lack of cooperation between physicians and dentists during osteoporosis treatment in the Shiga prefecture in Japan is documented in this study.

Expressions of ezrin, ERK, STAT3, and AKT in tongue cancer and association with tumor characteristics and patient survival.

BACKGROUND: Ezrin, ERK, STAT3, and AKT are proteins that are overexpressed in various types of cancer, although their expressions in tongue cancer has received less focus. This study aimed to address associations between the expression levels of these proteins and with characteristics of the tumor and patient survival. METHODS: We performed immunohistochemical staining of ezrin, ERK, STAT3, and AKT in tumors from patients with tongue carcinoma in situ (CIS, n = 17) and tongue squamous cell carcinoma (SCC, n = 46). Statistical differences between the SCC versus the CIS cohorts were estimated by calculations of bivariate odds ratios of low versus high expression of the proteins. Fisher's exact tests were used to appraise interassociations between the proteins, as well as expression levels versus patient and tumor characteristics. Survival based on Kaplan-Meier statistics in combination log-rank tests were used to address potential effects of the patient and tumor characteristics versus 5-year survival rate. RESULTS: The relative high: low expression of all four proteins in the two cohorts differed, and particularly ERK was markedly overexpressed in the SCC versus the CIS cohort (odds ratio = 45.3, p < .01). The relative high: low expression each protein versus patient and tumor characteristics; showed associations between AKT expression and T stage (p = .002) plus node metastases (p = .12), and between ERK expression and drinking (p = .01) and smoking history (p = .01). There was no significant difference observed between ERK and the three other molecules, nor any significant difference between the degree of expression of each protein and the 5-year disease-specific survival rate. CONCLUSION: Ezrin, ERK, STAT3, and AKT appear to be involved in the progress from carcinoma in situ in the tongue into squamous cell carcinoma. ERK in particular is overexpressed, suggesting that ERK may be a novel therapeutic target for preventing tongue cancer.

ERK phosphorylation functions in invadopodia formation in tongue cancer cells in a novel silicate fibre-based 3D cell culture system.

To screen for additional treatment targets against tongue cancer, we evaluated the contributions of extracellular signal-related kinase (ERK), AKT and ezrin in cancer development. Immunohistochemical staining showed that ERK and ezrin expressions were significantly higher in invasive squamous cell carcinoma than in carcinoma in situ. To investigate the roles of ERK and ezrin in cancer development, we used the non-woven silica fibre sheet CellbedTM with a structure resembling the loose connective tissue morphology in a novel 3D culture system. We confirmed that the 3D system using CellbedTM accurately mimicked cancer cell morphology in vivo. Furthermore, cell projections were much more apparent in 3D-cultured tongue cancer cell lines than in 2D cultures. Typically, under conventional 2D culture conditions, F-actin and cortactin are colocalized in the form of puncta within cells. However, in the 3D-cultured cells, colocalization was mainly observed at the cell margins, including the projections. Projections containing F-actin and cortactin colocalization were predicted to be invadopodia. Although suppressing ezrin expression with small interfering RNA transfection caused no marked changes in morphology, cell projection formation was decreased, and the tumour thickness in vertical sections after 3D culture was markedly decreased after suppressing ERK activity because both the invasion ability and proliferation were inhibited. An association between cortactin activation as well as ERK activity and invadopodia formation was detected. Our novel 3D culture systems using Cellbed™ are simple and useful for in vitro studies before conducting animal experiments. ERK contributes to tongue cancer development by increasing both cancer cell proliferation and migration via cortactin activation.

The novel association between red complex of oral microbe and body mass index in healthy Japanese: a population based cross-sectional study.

Microbiota has been thought to be one of important environmental factors for obesity or Type 2 diabetes mellitus. Among oral microbe, Porphyromonas gingivalis, Treponema denticola and Tannellera forsythia are known as risk factors, so called red complex, for periodontitis. Red complex could also be a risk factor for obesity. However, recent study indicated that obesity was not improved by periodontal therapy. Thus, we performed a cross sectional study to reveal the association of oral microbe with body mass index in a healthy population. Healthy individuals were randomly recruited. The infections of oral microbe were identified by Taqman polymerase chain reaction. The relationships between number of red complex and body mass index or waist circumference were analyzed. Two hundred and twenty-two apparently healthy Japanese were enrolled. BMI and waist circumference as well as age, periodontitis, number of brushing teeth were significantly associated with the number of red complex after adjusting covariance. The effect size of body mass index or waist circumference was 0.023 (p = 0.028) or 0.024 (p = 0.024), respectively. Body mass index and waist circumference were independently associated with the number of red complex among apparently healthy Japanese. The current observation implies the possibility that oral microbe was associated with obesity in healthy population.

Periodontitis and Porphyromonas gingivalis in preclinical stage of arthritis patients.

PURPOSE: To determine whether the presence of periodontitis (PD) and Porphyromonas gingivalis (Pg) in the subgingival biofilm associates with the development of rheumatoid arthritis (RA) in treatment naïve preclinical stage of arthritis patients. METHODS: We conducted a prospective cohort study of 72 consecutive patients with arthralgia who had never been treated with any anti-rheumatic drugs or glucocorticoids. Periodontal status at baseline was assessed by dentists. PD was defined stringently by the maximal probing depth≧4 mm, or by the classification by the 5th European Workshop in Periodontology (EWP) in 2005 using attachment loss. Up to eight plaque samples were obtained from each patient and the presence of Pg was determined by Taqman PCR. The patients were followed up for 2 years and introduction rate of methotrexate (MTX) treatment on the diagnosis of RA was compared in patients with or without PD or Pg. RESULTS: Patients with PD (probing depth≧4mm) had higher arthritis activity (p = 0.02) and higher risk for future introduction of MTX treatment on the diagnosis of RA during the follow up than patients without PD (Hazard ratio 2.68, p = 0.03). Arthritis activity and risk for MTX introduction increased with the severity of PD assessed by EWP, although not statistically significant. On the other hand, presence of Pg was not associated with arthritis activity (p = 0.72) or the risk for MTX introduction (p = 0.45). CONCLUSION: In treatment naïve arthralgia patients, PD, but not the presence of Pg, associates with arthritis activity and future requirement of MTX treatment on the diagnosis of RA.

Risk factors and indices of osteomyelitis of the jaw in osteoporosis patients: results from a hospital-based cohort study in Japan.

BACKGROUND: Several studies have reported osteomyelitis of the jaw (OMJ) as a side effect of bisphosphonates (BPs), and the risk of oral BPs has been recently clarified. However, other systemic risk factors of OMJ remain unclear. Importantly, the possibility of risk classification based on the clinical characteristics of patients has not been explored. Here, we clarified risk factors of OMJ and evaluate the predictive accuracy of risk indices in osteoporosis patients. METHODS: We performed sub-analysis using a database developed for a retrospective cohort study in patients taking medications for osteoporosis at Kyoto University Hospital. Risk indices for OMJ were constructed using logistic regression analysis, and odds ratios (OR) for OMJ cases and 95% confidence intervals (CI) were estimated. Potential risk factors included in the statistical analysis were age; sex; diabetes; use of oral BPs, corticosteroids, cancer chemotherapy, antirheumatic drugs, and biologic agents; and their interactions. Risk indices were calculated by the sum of potential risk factors of an individual patient multiplied by the regression coefficients. The discriminatory power of the risk indices was assessed by receiver operating characteristic (ROC) analysis. RESULTS: In analysis of all patients, oral BPs (OR: 4.98, 95% CIs: 1.94-12.75), age (OR: 1.28, 95% CI: 1.06-1.60) and sex-chemotherapy interaction (OR: 11.70, 95% CI: 1.46-93.64) were significant risk factors of OMJ. Areas under the ROC curves of these risk indices provided moderate sensitivity or specificity regardless of group (0.683 to 0.718). CONCLUSIONS: Our data suggest that oral BP use, age, and sex-chemotherapy are predictors of OMJ in osteoporosis patients. The risk indices are moderately high, and allow the prediction of OMJ incidence.

Mastication and risk for diabetes in a Japanese population: a cross-sectional study.

BACKGROUND: Associations between mastication and insufficient nutrient intake, obesity, and glucose metabolism have been shown in previous studies. However, the association between mastication and diabetes has not been clarified. Our objective was to examine the association between mastication, namely masticatory performance or rate of eating, and diabetes in a population-based cohort. METHODS: We conducted a cross-sectional study of the association between mastication and diabetes in the Nagahama Prospective Cohort Study, an ongoing study which recruits citizens of Nagahama City in Shiga Prefecture, central Japan. 2,283 male and 4,544 female residents aged 40-74 years were enrolled from July 2009 to November 2010. Masticatory performance was evaluated by spectrophotometric measurement of color changes after masticating color-changeable chewing gum. Categorical rate of eating (fast, intermediate or slow) was self-assessed using a questionnaire. RESULTS: 177 males (7.7%) and 112 (2.4%) females were diagnosed with diabetes. We divided participants into four groups by quartile of masticatory performance, namely Q1 (lowest), 2, and 3 and 4 (highest). Compared to the lowest performance group, the multivariable adjusted odds ratio (OR) of diabetes was 0.91 (95% confidence interval (CI), 0.58-1.4) in Q2, 0.77 (95% CI, 0.48-1.2) in Q3, and 0.53 (95% CI, 0.31-0.90) in the highest group in males, and 1.2 (95% CI, 0.73-2.0), 0.95 (95% CI, 0.54-1.6) and 0.56 (95% CI, 0.30-1.0) in females. We also estimated ORs of diabetes by rate of eating. Compared to the fast eating group, ORs in males were 0.87 (95% CI, 0.61-1.2) in the intermediate group and 0.38 (95% CI, 0.16-0.91) in the slow group, and ORs in females were 0.92 (95% CI, 0.59-1.4) and 1.5 (95% CI, 0.73-3.0). CONCLUSIONS: These findings support the hypothesis that higher masticatory performance and slow eating prevent the occurrence of diabetes.

Assessing anteroposterior basal bone discrepancy with the Dental Aesthetic Index.

OBJECTIVE: To investigate dental appearance and cephalometric features, using a sample of orthognathic and/or orthodontic patients. A special interest was to identify the relationship of the Dental Aesthetic Index (DAI) with anteroposterior basal bone discrepancy (APBBD) and cephalometric indicators. MATERIALS AND METHODS: A full sample of 159 patients in two Japanese hospitals was used. Each patient was assessed with a preorthodontic dental cast and cephalometric radiography. RESULTS: Malocclusion with APBBD was more prevalent among high DAI subjects (P  =  .034, OR  =  1.04, 95% CI: 1.00-1.08), Class III malocclusion patients (P  =  .048, OR  =  2.32, 95% CI: 1.01-5.34) and male patients (P  =  .008, OR  =  2.96, 95% CI: 1.33-6.61). Participants scoring 88 points (the highest score in this sample) of the DAI had 16.84 times the risk of APBBD of those who scored 17 points (the lowest score in this sample). Patients with APBBD presented with a greater adjusted ANB angle (t  =  -8.10, P < .001) and a larger adjusted A-B/NF appraisal (t  =  -9.65, P < .001). The SNA angle (P < .001), the SNB angle (P  =  .002), the adjusted ANB angle (P  =  .001), and the adjusted A-B/NF appraisal (P  =  .035) were associated with DAI scores in cubic regression models. CONCLUSION: This study has demonstrated a relationship between the DAI and APBBD. Feasibility of using the adjusted ANB angle and the adjusted A-B/NF appraisal to assess severity of APBBD has been confirmed. The DAI may provide a supportive method to evaluate orthognathic needs. Future investigations are indicated.

A pragmatic method for electronic medical record-based observational studies: developing an electronic medical records retrieval system for clinical research.

OBJECTIVE: The use of electronic medical record (EMR) data is necessary to improve clinical research efficiency. However, it is not easy to identify patients who meet research eligibility criteria and collect the necessary information from EMRs because the data collection process must integrate various techniques, including the development of a data warehouse and translation of eligibility criteria into computable criteria. This research aimed to demonstrate an electronic medical records retrieval system (ERS) and an example of a hospital-based cohort study that identified both patients and exposure with an ERS. We also evaluated the feasibility and usefulness of the method. DESIGN: The system was developed and evaluated. PARTICIPANTS: In total, 800 000 cases of clinical information stored in EMRs at our hospital were used. PRIMARY AND SECONDARY OUTCOME MEASURES: The feasibility and usefulness of the ERS, the method to convert text from eligible criteria to computable criteria, and a confirmation method to increase research data accuracy. RESULTS: To comprehensively and efficiently collect information from patients participating in clinical research, we developed an ERS. To create the ERS database, we designed a multidimensional data model optimised for patient identification. We also devised practical methods to translate narrative eligibility criteria into computable parameters. We applied the system to an actual hospital-based cohort study performed at our hospital and converted the test results into computable criteria. Based on this information, we identified eligible patients and extracted data necessary for confirmation by our investigators and for statistical analyses with our ERS. CONCLUSIONS: We propose a pragmatic methodology to identify patients from EMRs who meet clinical research eligibility criteria. Our ERS allowed for the efficient collection of information on the eligibility of a given patient, reduced the labour required from the investigators and improved the reliability of the results.

Risk of osteomyelitis of the jaw induced by oral bisphosphonates in patients taking medications for osteoporosis: a hospital-based cohort study in Japan.

Oral bisphosphonates (BPs) represent the first line of prevention and treatment for osteoporosis. However, several studies have reported osteonecrosis of the jaw (ONJ), also known as osteomyelitis of the jaw (OMJ), as a side effect of these drugs. Although absolute risk is suggested to be low, information to date on the relative risk or attributable risk has in fact been limited. Here, we estimated risk of oral BPs for OMJ in osteoporosis patients taking oral BPs compared with other osteoporosis drugs. Using an electronic medical records retrieval system and manual confirmation of OMJ, we conducted a retrospective cohort study of patients taking medications for osteoporosis at Kyoto University Hospital between November 2000 and October 2010. To evaluate relative risks of oral BPs for OMJ, logistic regression analysis was performed and odds ratios (ORs) and 95% confidence interval (CIs) were estimated. In addition, sensitivity analyses were performed according to hierarchical diagnosis. A total of 4129 patients (59.6%) were prescribed BPs while 2794 (40.3%) received other osteoporosis drugs. Absolute risk for OMJ was estimated to range from 0.46% to 0.99% (95% CIs: 0.25-0.66 to 0.69-1.2) among patients receiving oral BPs and 0.071% to 0.17% (95% CIs: 0-0.17 to 0.022-0.33) among patients receiving other osteoporosis drugs. The attributable risks of oral BPs for OMJ were estimated to range from 0.38% to 0.81% (95% CIs: 0.38-0.39 to 0.80-0.81). ORs (95% CIs) adjusted for confounding factors were 5.0 (1.9-12.9) to 6.0 (1.3-26.1) for confirmed cases only. In terms of absolute and attributable risks, the risk of oral BPs for OMJ is considered to be less than 1% in patients with osteoporosis. However, oral BPs may increase the risk of OMJ compared with patients treated with other osteoporosis medications and the risk of side effects should be kept in mind.

Hypertension, periodontal disease, and potassium intake in nonsmoking, nondrinker african women on no medication.

The purpose of this cross-sectional study was to investigate the association of periodontitis and/or tooth loss with hypertension by excluding the common confounders. Eighty-one Tanzanian women who were aged 46-58 years, nonsmokers, nonalcoholic drinkers, and on no medication underwent clinical examination. Multiple-regression analysis showed that the severity of periodontitis was significantly correlated with increased systolic blood pressure and diastolic blood pressure. Simple-regression analysis indicated that the severity of periodontitis was inversely correlated with 24-hour urinary excretion of potassium (r = -0.579, P = 0.0004) and also inversely with the frequency of intakes of green vegetables (r = -0.232, P = 0.031) and fruits (r = -0.217, P = 0.0043). Low-potassium intake in the diet mostly accompanied by low dietary fiber intake increases BP as well as periodontal inflammation. Potassium intake may be an important factor linking periodontitis and hypertension in middle-aged nonsmoking and nonalcoholic women on no medication, although chronic inflammation such as periodontitis may cause hypertension through a more direct mechanism.

Isoflavones regulate innate immunity and inhibit experimental colitis.

BACKGROUND AND AIM: Dysregulated immune responses in the gut to luminal antigens can cause inflammatory bowel diseases (IBD). The roles played by dietary antigens in the pathogenesis or prevention of IBD are poorly understood. Soybean isoflavones are digested in large amounts and have many biological activities. The aim of this study was to determine whether isoflavones in aglycon and bioavailable forms have any effect on gut immunity and protect the host from tissue damage in a mouse model of colitis. METHODS: We administered daidzein-rich isoflavone aglycones (DRIA) to mice for 1 week and then treated them with 2% dextran sodium sulfate (DSS) in drinking water for 4 days to induce colitis. The effect of DRIA was evaluated by examining the histopathology of the colon, body weight changes, and functional analysis of mesenteric lymph node cells (MLN). RESULTS: DRIA inhibited interleukin (IL)-6 and IL-8 production by Toll-like receptor (TLR)2, and TLR4-stimulated monocytes in a dose-dependent manner. The mice administered DRIA had less inflammation and tissue damage in the colon than the control mice. This protective effect of DRIA was associated with a decrease in interferon-gamma, IL-6, and IL-12p40 secretion, and an increase in IL-10 secretion and low cell-activation status of antigen-presenting cells (APC) in MLN. CONCLUSION: Ingested DRIA can downregulate the functions of APC and inhibit DSS colitis.

CD4+CD25+ T cells regulate colonic localization of CD4 T cells reactive to a microbial antigen.

BACKGROUND: In patients with inflammatory bowel diseases, T-cell activation driven by microflora has been implicated as a mechanism causing clonal expansion and infiltration of CD4+ T cells in colonic lamina propria (LP). We explored a regulatory mechanism preventing infiltration of CD4+ T cells specific to a microbe-associated antigen in the gut. METHODS: SCID mice were reconstituted with CD4+ T cells specific to ovalbumin (OVA) and were orally administered with Escherichia coli engineered to produce OVA. RESULTS: OVA-specific CD4+ T cells (KJ1-26+) were recruited to colonic LP in an Ag-dependent manner, which was inhibited by adoptive transfer of naturally occurring CD4+CD25+ T (Treg) cells. KJ1-26+ T cells and Treg cells are localized preferentially to the colonic follicles that contain dendritic cells. In mice given Treg cells, LP CD4+ T cells showed a decrease in proliferative and interferon gamma response and an increase in transforming growth factor beta1 response to OVA stimulation. Treg cells inhibited both antigenic activation of effector CD4+ T cells and class II/CD80/CD86 up-regulation of dendritic cells. CONCLUSION: : Treg cells suppress recruitment of CD4+ T cells specific to a microbe-associated antigen to LP, which was associated with colocalization of effector CD4+ T cells and Treg cells in colonic follicles.

Antigenic activation of Th1 cells in the gastric mucosa enhances dysregulated apoptosis and turnover of the epithelial cells.

Colonization of Helicobacter pylori in the stomach leads to chronic gastritis with massive infiltration by Th1 cells. To assess a role played by those T cells in the remodeling of gastric epithelium, we activated gastric T cells utilizing mice with CD4 T cells bearing transgenic TCR with or without deficiency in either IL-4 or IFN-gamma or IL-12. Mice developed gastritis upon injection of an antigen into gastric mucosa. While neutrophil infiltration occurred even with a control antigen, infiltration by transgenic T cells was dependent on the specific antigen. The numbers of epithelial cells undergoing apoptosis and regeneration were increased in the mice with infiltrating T cells producing IFN-gamma and the alignment of those cells in the glands was markedly dysregulated. In contrast, mice deficient in Th1 response showed no increase in cell division and apoptosis of epithelial cells. Thus, Th1 type T cells infiltrating into gastric mucosa play an independent role in controlling turnover of epithelial cells.

A liver tolerates a portal antigen by generating CD11c+ cells, which select Fas ligand+ Th2 cells via apoptosis.

Administration of an antigen (Ag) per oral route leads to apoptosis of Ag-specific CD4(+) T cells and to development of Th2 cells expressing Fas ligand (FasL) in the liver. We determined whether presentation of an ingested Ag in the liver alone was enough to select these FasL(+)Th2 cells and explored how this selection was achieved in the liver. Ovalbumin (OVA) administered orally was colocalized with class II(+) cells in the periportal and parenchymal area of the liver. On coculture with naive OVA-specific CD4(+) T cells, hepatic CD11c(+) cells from mice fed OVA generated Ag-specific Th2 cells. This was achieved by apoptosis of CD4(+) T cells, decrease of interleukin 12 (IL-12) secretion, and increase of IL-18 secretion by the CD11c(+) cells. Addition of IL-12 to this coculture prevented apoptosis of the CD4(+) T cells, which was associated with up-modulation of IL-2 receptor beta chain expression. Administration of IL-12 to mice fed OVA prevented apoptosis of OVA-specific CD4(+) T cells in the liver. Moreover, adoptive transfer of hepatic CD11c(+) cells from mice fed OVA together with OVA-specific CD4(+) T cells led to development of Th2 cells as well as apoptosis of the transferred CD4(+) T cells in the lymph nodes of the recipient mice on immunization with OVA. In conclusion, presentation of an ingested Ag by hepatic CD11c(+) cells selects Th2 cells resistant to apoptosis in the liver, which is mediated in part by down-regulation of IL-12 secretion by the former cells.

Nutritional variation and cardiovascular risk factors in Tanzania--rural-urban difference.

OBJECTIVE: To assess the relationship between dietary factors and cardiovascular (CVD) risk factors in middle-aged men and women, in urban, rural and pastoral settings in Tanzania. DESIGN: Cross-sectional epidemiological study designed according to the protocol of the World Health Organisation (WHO) Cardiovascular Diseases and Alimentary Comparison (CARDIAC) study. SETTING: Three centres in Tanzania, namely Dar es Salaam (urban), Handeni (rural) and Monduli (pastoral population). SUBJECTS: The subjects, aged 47-57 years, were recruited randomly from administrative lists available from each centre. OUTCOME MEASURES: Blood pressure (BP) was measured using a centrally calibrated automatic BP machine (Khi machine). Dietary history of the participants was obtained using a standard questionnaire designed on the basis of a seven-day recall system. Height, weight, serum total cholesterol (TC) and high-density lipoprotein cholesterol (HDLC), haemoglobin A1c, sodium, potassium and magnesium were measured. RESULTS: The prevalence of hypertension (BP > or = 140/90 mmHg or antihypertensive drug use), obesity (body mass index (BMI) > or = 30 kg/m2) and hypercholesterolaemia (TC > 5.2 mmol/l) were lowest in the rural area. Consumption of green vegetables, milk, coconut milk, meat, and fish varied significantly between the three areas. Important determinants for BP among men were BMI (p < 0.001), and salt intake (p < 0.05). Among women, TC (p < 0.05), age (p < 0.05), BMI (p < 0.001) and coconut milk consumption (p < 0.001) were important BP determinants. Salt intake was positively associated with systolic BP (SBP) and diastolic BP (DBP) in men but not among women (both SBP and DBP p < 0.05 respectively). Dietary determinants of serum TC were meat, fish and green vegetable consumption. CONCLUSION: Differences in dietary habits contributed significantly to the urban-rural-pastoral variations in CVD risk pattern in Tanzania.

Helper CD4+ T cells for IgE response to a dietary antigen develop in the liver.

BACKGROUND: Although T-cell responses to food antigens are normally inhibited either by deletion, active suppression, or both of antigen-specific T cells, T helper cells for IgE response to a food antigen still develop by unknown mechanisms in a genetically susceptible host. OBJECTIVE: We determined the site at which those IgE helper T cells develop. METHODS: We administered ovalbumin (OVA) orally to DO11.10 mice and studied CD4+ T cells in Peyer's patches, the spleen, and the liver. Helper activity for IgE response was assessed by adoptively transferring those CD4+ T cells to naive BALB/c mice, followed by systemic immunization with OVA. RESULTS: OVA-specific CD4+ T cells were deleted by cell death in the liver and Peyer's patches of DO11.10 mice fed OVA. OVA-specific CD4+ T cells that survived apoptosis in the liver expressed Fas ligand and secreted IL-4, IL-10, and transforming growth factor beta(1). CD4+ T cells producing IFN-gamma were deleted in the liver by repeated feeding of OVA. On transfer of CD4+ T cells to naive mice and systemic immunization with OVA, a marked increase in OVA-specific IgE response developed only in the mice that received hepatic CD4+ T cells from OVA-fed mice, the effect of which was not observed in the recipients of hepatic CD4+ T cells deficient in IL-4. In addition, significant suppression of delayed-type hypersensitivity and IgG(1)/IgG(2a) responses to OVA was observed in the recipients of hepatic CD4+ T cells, and this suppression required Fas/Fas ligand interaction. CONCLUSION: Together, these results suggested that a food antigen might negatively select helper T cells for IgE response to the antigen by preferential deletion of T(H)1 cells in the liver.

Differential localization of colitogenic Th1 and Th2 cells monospecific to a microflora-associated antigen in mice.

BACKGROUND & AIMS: Clonal expansion of T cells is associated with inflammatory bowel diseases, which indicates antigenic activation of the T cells. We investigated whether the introduction of CD4 T cells specific to a microflora would initiate colitis and assessed the cytokine requirements for colitogenic CD4 T cells. METHODS: Severe combined immunodeficiency disease (SCID) mice were reconstituted with CD4 T cells, which were either deficient in interleukin (IL)-4/interferon (IFN)-gamma production or differentiated in vitro to T-helper (Th) 1/Th 2 and bearing a transgenic T-cell receptor (TCR) specific to ovalbumin (OVA), and then inoculated with an Escherichia coli-producing OVA (ECOVA). Clinical and histologic manifestations of colitis were assessed. RESULTS: Mice with ECOVA colonization and OVA-specific CD4 T cells developed colitis with histologic features of focal infiltration by mononuclear cells, destruction of crypts, and loss of goblet cells. Further, infiltration was initiated in pre-existing lymph follicles. Th1- and IL-4 deficient T cells were diffusely localized in the lamina propria and submucosa, whereas Th2- and IFN-gamma-deficient T cells were localized preferentially in lymph follicles. CONCLUSIONS: A microbe-associated antigen, non-cross-reactive to colonic tissue, can drive antigen-specific CD4 T cells to cause colitis in SCID mice. Although the presence of IFN-gamma and IL-4 in the effector CD4 T cells was not an absolute requirement for the development of colitis, they seemed to regulate it in part by modulating migration of the effector T cells.

Prevalence of overweight and hypertension in Tanzania: special emphasis on resting energy expenditure and leptin.

1. In the present study we investigated the difference in the distribution of selected cardiovascular disease risk factors among three middle-aged Tanzanian populations with different lifestyles. 2. The prevalence of hypertension and overweight was higher in urban areas than in rural areas. Plasma leptin concentration was also highest in urban areas. Based on these results, we speculated that overweight in the urban population may be partly due to adiposity. 3. Resting energy expenditure was lower in urban areas than in other areas for both genders. These findings suggest that the high prevalence of overweight in the urban population may be partly due to low physical activity levels.

Administration of an antigen at a high dose generates regulatory CD4+ T cells expressing CD95 ligand and secreting IL-4 in the liver.

Ags administered orally at a high dose are absorbed in immunogenic forms and perfuse the liver, which raises a question regarding the relevance of hepatic lymphocyte activation to the systemic hyporesponsiveness against the ingested Ag. Oral administration of 100 mg of OVA to the mice led to massive cell death of OVA-specific (KJ1-26+)CD4+ T cells by Fas-Fas ligand (FasL)-mediated apoptosis in the liver, which was associated with the emergence of hepatic KJ1-26+CD4+ T cells expressing FasL. Hepatic CD4+ T cells in OVA-fed mice secreted large amounts of IL-4, IL-10, and TGF-beta(1) upon restimulation in vitro and inhibited T cell proliferation. Adoptive transfer of these hepatic CD4+ T cells to naive mice and subsequent antigenic challenge led to suppression of T cell proliferation as well as IgG Ab responses to OVA; this effect was mostly abrogated by a blocking Ab to FasL. i.p. administration of an Ag at a high dose also generated hepatic CD4+FasL+ T cells with similar cytokine profile as T cells activated by oral administration of Ags at a high dose. Finally, we did not see an increase in FasL+ cells in the hepatic CD4+Vbeta8+ T cell subset of MRL/lpr/lpr mice given staphylococcal enterotoxin B, indicating the requirement for Fas-mediated signals. These hepatic CD4+FasL+ regulatory cells may explain the tolerogenic property of the liver and play roles in systemic hyporesponsiveness induced by an Ag administered at a high dose.