Matrix metalloproteinases and their inhibitors in gingival mast cells in persons with and without human immunodeficiency virus infection

BACKGROUND: Mast cells are a prominent cell type in the gingival infiltrate in periodontitis. In this study we examined the expression by gingival mast cells of matrix metalloproteinases, MMP-1, MMP-2, MMP-8 and the tissue inhibitors of metalloproteinases, TIMP-1 and TIMP-2. METHODS: Gingival specimens from 12 human immunodeficiency virus-negative (HIV-) and 15 HIV-positive (HIV+) patients with chronic marginal periodontitis (CMP), and from 10 HIV- and four HIV+ controls with clinically healthy gingiva (HG) were examined after double immunofluorescence staining for mast cell tryptase, combined with antibodies for MMP-1, MMP-2, MMP-8 or their inhibitors TIMP-1 and TIMP-2. RESULTS: In the HIV+CMP, HIV+HG and HIV-CMP groups, all mast cells expressed MMP-1 and MMP-8, whereas a smaller proportion (40-60%) in the HIV-HG controls displayed such staining. The former groups also displayed a significantly higher proportion (39-64%) of mast cells expressing MMP-2 as compared with the HIV-HG group (21-31%). All groups displayed similar proportions of TIMP-1 expressing mast cells (86-100%), whereas significantly increased proportions of TIMP-2+ mast cells were seen in the HIV+CMP, HIV+HG and HIV-CMP groups (18-25%) as compared with the HIV-HG group (8-13%). Mast cells were the cell type that most prominently expressed MMP-1 and MMP-8. MMP-2 expression was also strong in mast cells, but was also similarly expressed in other cell types. CONCLUSION: The chronically inflamed periodontal lesions in the present study appeared with little evidence of mast cell degranulation. The results show, however, that mast cells in inflamed gingiva have the potential to degrade extracellular matrix if appropriately triggered.     

Longitudinal study of the influence of removable partial denture and chemical control on the levels of Streptococcus mutans in saliva

Some studies have evaluated the salivary levels of mutans streptococci (MS) in removable partial denture (RPD) users. Saliva samples (2.0 mL) were obtained from 31 patients in six periods: (T0): immediately before installation of RPD; (T8): 8 days after T0; (T48): 48 days after T0; (T92): 92 days after T0; (T140): 140 days after T0 and (T189): 189 days after T0. The samples were vortexed and serially diluted from 10(-1) to 10(-6) in 0.05 m phosphate buffer (pH 7.4). From each dilution, 0.025 mL was plated on Mitis Salivarius Bacitracin (MSB). The plates were incubated in 5% CO2 at 37 degrees C for 72 h. There was an increase (t-test, P < 0.05) in the number of MS between periods T0 and T48 (mean/s.d., CFU mL(-1) of saliva): T0: 2.26/4.43 x 10(6) and T48: 0.47/1.48 x 10(8). After this, intensive treatment with CHX was accomplished in 29 patients. Saliva samples were obtained after treatment in four periods: (T24 h): 24 h after T0; (T14): 14 days after T24 h; (T28): 28 days after T24 h, and (T63): 63 days after T24 h. The number of MS in saliva did not decrease (t-test, P > 0.05). A new CHX formulation was applied in 15 patients. Saliva samples were obtained in periods: (T0): before new CHX application; (T24 h): 24 h after T0 and (T82): 82 days after T0. The new CHX reduced MS levels in saliva: (mean/s.d., CFU mL(-1) of saliva): T0: 6.64/8.47 x 10(6) and T24 h: 3.2/4.27 x 10(5) (sign rank, P < 0.05). In conclusion, there was a significant increase in the number of MS in saliva after the installation of RPD. The intensive treatment with a properly formulated CHX was effective in the reduction of MS, between 24 h and 82 days after its application.     

Activation of pain by sumatriptan

OBJECTIVE: To demonstrate that sumatriptan may induce activation or aggravation of pain at sites of inflammation caused by trauma or disease. METHODS: Case reports from the national pharmaco vigilancecenters of 2 countries, The Netherlands and New Zealand, are presented. These reports come from programs that use 2 methodologies to monitor drugs for adverse reactions: spontaneous reporting and a prospective observational cohort study. The potential mechanisms for pain production by sumatriptan are discussed in detail. RESULTS: Thirteen case reports of activation of pain by sumatriptan following injury and 8 associated with inflammatory diseases are presented. Most patients had one or more positive rechallenges. This type of reaction occurred at a higher rate with the subcutaneous formulation than with the oral preparation. Pain mostly was severe but short-lasting; pain was prolonged in some patients with inflammatory disease. CONCLUSIONS: A strong association has been demonstrated between the use of sumatriptan and the production of pain at sites of inflammation, and there is a plausible pharmacological mechanism for this reaction. Pain activation may be a class effect of the selective serotonergic agonists used in the treatment of migraine.     

Bacterial communication and group behavior

The existence of species-specific and interspecies bacterial cell-cell communication and group organization was only recently accepted. Researchers are now realizing that the ability of these microbial teams to communicate and form structures, known as biofilms, at key times during the establishment of infection significantly increases their ability to evade both host defenses and antibiotics. This Perspective series discusses the known signaling mechanisms, the roles they play in both chronic Gram-positive and Gram-negative infections, and promising therapeutic avenues of investigation.     

Tracheal spindle cell tumor in a child

Tracheal tumors in the pediatric population are rare neoplasms that have devastating consequences if not evaluated and diagnosed in a timely fashion. As illustrated by this case, the tumors typically do not become symptomatic until marked airway obstruction occurs, and patients may present with acute respiratory distress. Radiologic advances, including 3-D CT tracheal reconstruction, are invaluable in the diagnosis of and surgical planning for tracheal neoplasms.     

Cochlear implantation after radical mastoidectomy: management of a challenging case

Due to increasing experience and technological improvement, the selection criteria for cochlear implantation have improved. Cochlear implant application can now be performed in selected patients with pathological middle ear lesions. The surgical approach to a patient with a history of bilateral radical mastoidectomy is addressed in detail. The benefits of cochlear implantation in this case are also discussed.     

Implications of carrier identification in newborn screening for cystic fibrosis

OBJECTIVE: To investigate the psychosocial implications for families whose infant was identified as a cystic fibrosis carrier by newborn screening. DESIGN: Prospective psychosocial assessment. SETTING: Primary care. RESPONDENTS: Study: (a) families of an affected infant identified by screening (n = 9); (b) families of a carrier infant identified by screening (n = 10). Control: group of mothers from the general population (n = 82). INTERVENTIONS: Questionnaires and semistructured interviews. MAIN OUTCOME MEASURES: Attitude to screening, assessments of the mother/baby relationship, anxiety, wellbeing. RESULTS: All families were in favour of screening, with no evidence that the mother/baby relationship, anxiety or wellbeing had been adversely affected. Parents, however, did identify problems in terms of the service delivery protocol and genetic counselling practice. CONCLUSION: Six months after disclosure, carrier identification was not perceived by parents to be problematic.     

Laser fluorescence in assessing the hygienic status of oral cavity

The issue related with an objective evaluation of a hygienic status of the oral cavity and a method to solve it by modern laser technologies are addressed in the paper. The efficiency of bacteriological and of laser-fluorescence express-diagnostics is comparatively analyzed. A hygienic index and its clinical value are substantiated.