Langerhans-like dendritic cells generated from cord blood progenitors internalize pollen allergens by macropinocytosis, and part of the molecules are processed and can activate autologous naive T lymphocytes

Background: The safety and efficacy of sublingual immunotherapy have been demonstrated in moderate allergic asthma and seasonal rhinitis. However, not much is known about the precise mechanism of action of the allergen when it crosses the oral mucosa. Objective: To define this mechanism, we investigated the role of Langerhans’ cells in the capture and internalization of allergens. Methods: We generated dendritic cells in vitro with the phenotypic characteristics of Langerhans-like dendritic cells (LLDCs) from cord blood CD34⁺ progenitors. We used two recombinant major allergens: Bet v 1 and Phl p 1 labeled with FITC. Results: Internalization of allergens and control proteins was dose- and time-dependent and related to the immature state of the cells. LLDCs internalized allergens with a high efficiency in comparison with control molecules. Allergens were only internalized by macropinocytosis, as demonstrated by the use of various inhibitors. Addition of intracellular pH-modifying molecules indicated that only a part of the allergens was accumulated in acidic vesicles, whereas the majority remained in other cytoplasmic structures. Pulse-chase experiments calculated a half-life of 4 hours, suggesting that part of the molecules were not metabolized in the lysosome. Allergen internalization by LLDCs might be followed by processing in some experiments, as demonstrated by activation of autologous T lymphocytes in 4 of 9 experiments. Conclusion: These elements showed that Langerhans’ cells present in mucosa might play an active role in immune responses to allergens. (J Allergy Clin Immunol 2000;105:1194-1201.)     

The friction and wear patterns of orthodontic brackets and archwires in the dry state

Frictional resistance at the bracket-archwire interface has been demonstrated to impede tooth movement when sliding mechanics are used. Thus, the coefficients of friction of titanium and stainless steel brackets used in conjunction with stainless and ion-implanted beta-titanium archwires were investigated using a single contact interface between the brackets and archwires. The wear patterns between the brackets and the.016- in flat archwire surfaces were also examined using scanning electron microscopy and energy dispersive x-ray analysis. Stainless steel brackets tested with. 016-in flat stainless steel wire surfaces recorded the lowest coefficient of static friction mean (0.289), whereas titanium brackets paired with.016-in flat ion-implanted beta-titanium wire surfaces produced the highest mean (0.767). Stainless steel brackets had significantly (P <.05) lower coefficients of friction than titanium brackets for all wires except.020-in round stainless steel wires. Ion-implanted beta-titanium wires generally had significantly larger coefficients of friction than stainless steel wires. The increased friction of the titanium and ion-implanted beta-titanium alloys is also reflected in the severity of their wear patterns. An inverse relationship between friction and archwire surface dimension was generally found for ion-implanted beta-titanium wires. Round stainless steel wires demonstrated lower coefficients of kinetic friction than the flat stainless steel wire surfaces.     

Expression of IL-15 in inflammatory pulmonary diseases

BACKGROUND: IL-15 is a T(H)1-related cytokine that shares many biologic activities with IL-2. Both cytokines bind a specific alpha subunit, and they share the same beta and gamma common receptor subunits for signal transduction. IL-15 has recently been shown to be upregulated in T cell-mediated inflammatory disorders, such as rheumatoid arthritis and inflammatory bowel diseases. However, the role and expression of IL-15 in inflammatory lung disease has not been investigated. OBJECTIVE: In the present study we have evaluated the expression of IL-15 mRNA and protein in bronchial biopsy specimens obtained from patients with sarcoidosis (n = 8), tuberculosis (n = 7), chronic bronchitis (n = 10), and bronchial asthma (n = 8) and compared its expression with that seen in normal control subjects (n = 11). METHODS: In situ hybridization and immunocytochemistry were used to detect the number of cells expressing IL-15 mRNA and protein, respectively, within sections of bronchial tissues from all subject groups. In addition, double immunocytochemistry was used to characterize the cellular source of IL-15. RESULTS: The number of IL-15(+) cells was significantly higher within tissue from patients with sarcoidosis, tuberculosis, and chronic bronchitis compared with that in asthmatic patients and normal control subjects. Similar results were obtained for IL-15 immunoreactivity by using immunohistochemistry. Furthermore, double immunostaining revealed that neutrophils and macrophages are the major source of IL-15. CONCLUSION: These results suggest that the expression of IL-15 may be associated with T(H)1-mediated chronic inflammatory diseases of the lung.     

The relationship between intercanthal dimension and the widths of maxillary anterior teeth

STATEMENT OF PROBLEM: One of the difficult aspects of complete denture prosthodontics is the selection of appropriately sized maxillary anterior teeth. Many attempts have been made to establish methods of estimating the combined width of maxillary anterior teeth and/or central incisors. PURPOSE: The aim of this investigation was to determine whether a relationship exists between the intercanthal dimension and 4 mesiodistal width combinations of the maxillary anterior teeth. MATERIAL AND METHODS: The maxillary anterior teeth of 443 adult subjects were examined. Intercanthal distance was measured between the median angles of the palpebral fissure. The mean widths of the 2 central incisors, the combined widths of the central incisors, the combined width of the 4 incisors, and the combined width of the 6 anterior teeth were determined intraorally at their widest dimension. Pearson correlation coefficients were calculated to determine the relationship between intercanthal distance and the 4 measurements of maxillary anterior teeth (alpha=.05). RESULTS: Although the Pearson correlation coefficients were relatively small, a significant relationship existed between intercanthal dimension and the 4 maxillary teeth dimensions (P<.0001). It was found that biometric ratios of 1:0.267 and 1:1.426 could be used to estimate the central incisor width and the combined widths of the 6 anterior teeth, respectively. CONCLUSION: Within the limitations of this study, the results suggest that intercanthal distance can be used as a preliminary method for determining the width of the maxillary anterior teeth for edentulous patients.     

Prevalence of subjective dry mouth and burning mouth in hospitalized elderly patients and outpatients in relation to saliva, medication, and systemic diseases

OBJECTIVE: The purpose of this study was to investigate the prevalence of self-reported symptoms of dry mouth and burning mouth in the frail elderly. We expected to find the studied symptoms more frequently in the frail elderly than in those who were healthier. STUDY DESIGN: We examined 175 home-living elderly patients (mean age with SD, 82 +/- 5.7 years) hospitalized because of sudden worsening of their general health. For comparison, 252 elderly outpatients (mean age with SD, 77 +/- 5.7 years) from the same community were studied. The subjects' medical diagnoses and prescribed drugs used daily were recorded, their oral health examined, and saliva samples taken for analyses of flow rates, yeasts, and a variety of biochemical factors. RESULTS: The results showed that 63% of the hospitalized patients and 57% of the outpatients complained of dry mouth. The respective percentages of burning mouth were 13% in the hospitalized and 18% in the outpatients. The dentate status affected the feeling of dry mouth and burning mouth, but there were no consequent differences in concentrations of salivary biochemical constituents, yeast counts, and buffering capacity between patients with or without the symptoms except that hospitalized patients complaining of dry mouth more often had low salivary buffering than those without the symptom. Dry mouth was also more prevalent among the hospitalized patients who used several drugs daily, whereas no such association was found with the burning-mouth symptom. Use of analgesics appeared to safeguard against both the symptoms. Dry mouth and burning mouth were seldom reported simultaneously, although low salivary flow rate was a common finding in patients with burning mouth. The strongest explanatory factors for burning mouth were psychiatric disease among the outpatients (OR 8.7, CI 1.4-54.1, P <.05) and use of psychiatric drugs among the hospitalized (OR 4.2, CI 0.9-20.0, P =.07). For dry mouth, the strongest explanatory factors were respiratory disease in the outpatients (OR 2.0, CI 1.0-3.8, P <.05) and low salivary flow rate in the hospitalized elderly (OR 3.7, CI 1.4-10, P <.05). In all patients (n = 427), use of psychiatric drugs was the strongest explanatory factor for dry mouth (OR 2.1, CI 1.2-3.5, P <.01), whereas analgesic medication was found to protect against burning mouth (OR 0.5, CI 0.3-0.9, P <.05). CONCLUSION: The subjective feelings of dry mouth and burning mouth appeared to be a complex issue among the elderly population studied. The 2 symptoms were seldom reported at the same time. The appearance of symptoms did not directly correlate with general health, except in the case of psychiatric diseases and medications, which should be taken into account.     

Distal aortic diameter and peripheral arterial occlusive disease

OBJECTIVE: Several studies have reported an association between abdominal aortic dilatation and peripheral arterial occlusive disease. Narrowing of aortic diameter, also called abdominal aortic hypoplasia, and peripheral arterial occlusive disease have received insufficient attention. Precise estimates of the relationship between aortic hypoplasia and peripheral arterial occlusive disease are lacking. In this study, we assessed the relationship between abdominal aortic diameter and peripheral arterial occlusive disease. METHODS: In this cross-sectional study, we analyzed 1572 patients 18 to 79 years of age, newly referred to the vascular center of our hospital with clinically manifest atherosclerotic arterial disease or for treatment of cardiovascular risk factors. Diameter measurements were used to subdivide patients according to tertiles of abdominal aortic diameter. Peripheral arterial occlusive disease was assessed by adjusted Rose questionnaire, ankle-brachial pressure index, and the presence of gangrene or leg ulcers. RESULTS: Compared with patients with normal aortic diameter, peripheral arterial occlusive disease was twice as prevalent in patients at both ends of the aortic diameter spectrum. When the lowest tertile was compared with the middle tertile in male patients, the adjusted odds ratio was 1.7 (95% CI, 1.0-3.1). When the highest tertile was compared with the middle tertile, the adjusted odds ratio was 2.1 (95% CI, 1.2-3.4). Similar results were found in female patients. The adjusted odds ratio of lowest versus middle tertile was 2.4 (95% CI, 1.1-5.0) and 1.8 (95% CI, 0.8-4.0) when the highest tertile was compared with the middle tertile. CONCLUSION: The risk of peripheral arterial occlusive disease was increased in the lower and upper distribution of aortic diameter. Apparently, both patients with an aortic diameter too large and patients with an aortic diameter too small are prone to peripheral arterial occlusive disease. This is the first large study that shows that small aortic diameter is associated with peripheral arterial occlusive disease.     

Immunomorphologic studies of mast cell heterogeneity, location, and distribution in the rat conjunctiva

Mast cells are crucial components of immediate and some delayed-type hypersensitivity reactions. They play a pivotal role in allergic conjunctivitis and other immunoinflammatory disorders of the ocular surface, yet little is known of their distribution and heterogeneity in the conjunctiva of potential animal models, such as the rat. In this study, mast cell types were investigated in histologic sections and corneal-conjunctival-lid whole mounts by using toluidine blue, alcian blue–safranin, and immunohistochemical staining methods (anti-rat mast cell proteinase [RMCP] antibodies). Quantitative analyses were performed on corneal-conjunctival-lid whole mounts by using the optical dissector procedure to obtain the density of mast cells per unit volume in different regions of the conjunctiva. Single and double immunohistochemical analyses revealed that the mast cells in the conjunctiva of the limbus, fornices, and lid margin were strongly RMCP I⁺, suggesting that they were of the connective tissue phenotype. Mast cells containing the mucosal mast cell proteinase RMCP II were not present in the normal conjunctiva. Histochemical analysis revealed that the maturity of the connective tissue mast cells, as assessed by the presence or absence of safranin (heparin)-positive granules in their cytoplasm varied in different regions. In the lid margin 60% to 78% of the mast cells were solely alcian blue–positive, whereas in the fornices 68% to 78% were safranin-positive. In the limbus the predominant type of mast cell was either safranin-positive or contained mixed granules. Mast cell densities were greatest close to the lid margin (10,000 to 12,000 cells/mm³), followed by the limbus (3400 to 4800 cells/mm³) and were rare in the remainder of the conjunctiva (500 to 1000 cells/mm³), with the exception of the region around the nictitating membrane. This study of rat conjunctival mast cells provides essential baseline data for future studies of the role of mast cells in models of allergic conjunctivitis. (J ALLERGY CLIN IMMUNOL 1996;97:1375-86.)