Measurement of brain lactate during visual stimulation using a long TE semi‐LASER sequence at 7 T

Estimation of metabolic changes during neuronal activation represents a challenge for in vivo MRS, especially for metabolites with low concentration and signal overlap, such as lactate. In this work, we aimed to evaluate the feasibility of detecting lactate during brain activation using a long (144 ms) semi‐LASER sequence at 7 T. spectra were acquired on healthy volunteers ( ) during a paradigm with 15 min of visual stimulation. Outer‐volume signals were further attenuated by the use of saturation slabs, and macromolecular signals in the vicinity of the inverted lactate peak were individually fitted with simulated Lorentzian peaks. All spectra were free of artefacts and highly reproducible across subjects. Lactate was accurately quantified with an average Cramér‐Rao lower bound of 8%. Statistically significant ( , one‐tailed ‐test) increases in lactate ( 10%) and glutamate ( 3%) levels during stimulation were detected in the visual cortex. Lactate and glutamate changes were consistent with previous measurements. We demonstrated that quantification of a clear and non‐contaminated lactate peak obtained with a long TE sequence has the potential of improving the accuracy of functional MRS studies targeting non‐oxidative reaction pathways.     

Isotypic antibody response to plaque anaerobes in periodontal disease

BACKGROUND: It has been suggested that locally produced immunoglobulin (Ig)A could be more protective than IgG and that there could be a relationship between crevicular fluid-specific IgA levels and the onset of periodontal disease. This study was designed to investigate this hypothesis regarding specific immune responses towards 4 plaque anaerobes in gingival crevicular fluid and saliva from patients with periodontopathies and controls. METHODS: Gingival crevicular fluid (GCF) and whole saliva were collected from 35 adults with periodontitis and 24 periodontally healthy adults (controls). Antigens were extracted from Actinomyces actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, and Fusobacterium nucleatum and used to set up specific enzyme-linked immunosorbent assay (ELISA) tests to assess IgA and IgG levels to these microorganisms in the fluids collected. RESULTS: The crevicular fluid of periodontitis patients contained significantly higher levels of IgG to the 4 microorganisms tested than that of controls (P < 10(-6) for all comparisons). IgA levels to the 4 bacteria were statistically significantly much higher in control crevicular fluid (P < 10(-7) for all comparisons). Controls also had statistically significantly higher levels of specific salivary IgA than patients (P < 0.02 for all comparisons). CONCLUSIONS: These data support the potentially protective role of specific IgA directed to oral microorganisms involved in the onset and development of periodontal disease.     

Langerin+ versus CD1a+ Langerhans cells in human gingival tissue: a comparative and quantitative immunohistochemical study

Langerhans cells (LC) are dendritic cells of the immune system able to capture intraepithelial pathogens and migrate to regional lymph nodes to present them to naive T cells. Up to now immunohistological studies on human gingival LC have been carried out using antibodies against HLA-DR or CD1a molecules. A new marker of LC called Langerin (CD207) and described, among other subcellular localisations, in the Birbeck granules is now available in immunohistochemistry. The purpose of this in situ study was to quantify and to compare Langerin+ versus CD1a+ LC number in order to show differences in the expression of these molecules, if any, and to determine which marker is the most specific. The present study was conducted using nine frozen healthy gingival samples. Double immunofluorescence procedures were performed with an anti-Langerin antibody revealed by FITC and with an anti-CD1a-PE antibody. Mounted slides were analysed by fluorescence microscopy and quantifications were performed on projected slides associated with a grid of 0.015 mm(2). Our results have shown that 1/ the number of CD1a+ LC was significantly increased (P=0.01) when compared with Langerin+ LC 2/ 92% of Langerin+ LC co-expressed CD1a 3/ only 82% of CD1a+ cells co-expressed Langerin 4/ a positive correlation was noted between CD1a+ and Langerin+ LC numbers. The present study has revealed the heterogeneity in the phenotype of gingival LC population and shown that Langerin seems the most specific marker for the study of LC.     

Preemptive rofecoxib and dexamethasone for prevention of pain and trismus following third molar surgery *

Objective The goal of this preliminary randomized prospective clinical trial was to compare the analgesic efficacy and the reduction in trismus of preoperative rofecoxib, intraoperative dexamethasone, and both rofecoxib and dexamethasone following third molar extraction surgery. Study design Thirty-five subjects requiring surgical removal of at least 1 partial bony impacted mandibular third molar were invited to participate in this double-blind and double-dummy placebo-controlled clinical trial. Subjects were randomly assigned into 1 of 4 treatment groups: (1) placebo po preoperatively and placebo IV intraoperatively; (2) rofecoxib 50 mg po preoperatively and placebo IV intraoperatively; (3) placebo po preoperatively and dexamethasone10 mg IV intraoperatively; and (4) rofecoxib 50 mg po preoperatively and dexamethasone 10 mg IV intraoperatively. Subjects completed a diary assessing postoperative pain onset and intensity using categorical and visual analogue scales. Interincisal opening was assessed 1, 2, 3, and 7 days postoperatively using a Therabite ruler. Results This randomized controlled clinical trial enrolled 35 subjects. Two subjects did not meet the inclusion criteria and 4 did not return completed diaries. The mean age of the remaining 29 subjects (11 males, 18 females) was 22.8 years (+/- 0.6 year). The active treatments tended to delay the need for initial pain medication. When compared to other active treatments and to placebo, the combination of preoperative rofecoxib and intraoperative dexamethasone significantly reduced initial pain intensity ( P < .05). Baseline interincisal opening was 52.6 mm (+/- 6.2). The greatest decrease in interincisal opening was 43.3% for the placebo group at 24 hours. Preoperative rofecoxib alone showed a decrease in interincisal opening of 42.3% ( P = ns) at 24 hours. Intraoperative dexamethasone alone showed a decrease in the interincisal opening of 24.1% of baseline ( P < .05 vs placebo). The group receiving the combination of rofecoxib and dexamethasone showed a decrease in interincisal opening of 23.7% of baseline ( P < .05 vs placebo). Conclusions The results of this trial indicate that the use of intraoperative dexamethasone is an effective therapeutic strategy for limiting trismus following surgical removal of impacted third molars. The combination of preoperative rofecoxib 50 mg and intraoperative dexamethasone 10 mg was most effective in minimizing pain and trismus following third molar surgery.     

The anchorage of Brånemark and ITI implants of different lengths. I. An experimental study in the canine mandible

Abstract: The anchorage of machined Brånemark and ITI TPS‐coated implants of various lengths was investigated in an animal model. Brånemark fixtures 7 and 10 mm long and ITI implants 6 and 10 mm long were inserted in the mandible of dogs and were reverse‐torqued after 3 months of healing. The failing mode was different for the two implant systems. For the ITI implants, loosening coincided with the peak reverse‐torque values. For the Brånemark fixtures, two reverse‐torque values were identified and recorded, a ‘start to rotate’ and a peak value. The ‘start to rotate’ values for the 7 and 10 mm Brånemark fixtures were 36.67 and 38.57 Ncm, respectively, the peak values were 61.88 and 69.13 Ncm. The increase in implant length from 7 to 10 mm did not significantly improve the anchorage. The mean reverse‐torque values for the 6‐ and 10‐mm ITI implants were 104.66 and 192.25 Ncm, respectively; the difference was statistically significant. The mean removal torque of the 6‐mm ITI implant was higher than the 7‐ and 10‐mm Brånemark implants. It is suggested that the distinct anchorage magnitude and the distinct loosening patterns registered for both implant systems might be related to the various surface states. The latter might account for the different failure tendencies mentioned in the literature for short Brånemark and ITI implants.     

Angioleiomyoma of the tongue

A case of angioleiomyoma of the tongue is detailed. The patient sought treatment for a painless, rubbery mass of 10 years duration. The tumor was unusual, appearing bilobed, with the dorsal aspect whitish in color and a blue ventral component. Occasional episodes of numbness were noted. Biopsy of the lesion demonstrated bundles of smooth muscle cells surrounding numerous vascular spaces. The patient was lost to follow-up; as a result, a complete surgical excision of the tumor was not performed.