Evaluation of MR angiographic technique in the assessment of thoracic outlet syndrome.

AIM: To evaluate two-dimensional time of flight (2D TOF) and three-dimensional contrast-enhanced magnetic resonance angiographic (3DCE MRA) techniques in the assessment of patients with suspected thoracic outlet syndrome (TOS) of vascular origin. MATERIALS AND METHODS: Fifty-five consecutive examinations, in 51 patients with suspected TOS of vascular origin, were examined using either a 1T or 1.5T Siemens magnetic resonance imaging (MRI) unit, using either 2D TOF (n=13) or 3DCE MRA (n=42). Examinations were performed with the arms abducted (n=27) or both abducted and adducted (n=28). The source images and MIPs were reviewed retrospectively and assessed for image quality and the presence of significant persistent stenosis or impingement (a >60% reduction in the diameter of the subclavian vessels at the thoracic outlet or evidence of post-stenotic dilatation). When significant impingement was identified, the images were reformatted with multiplanar reconstruction to determine the cause. RESULTS: Images were sub-optimal in 53% 2D TOF and 10% 3DCE MRA examinations. 3DCE MRA offered vessel coverage from the aortic arch to the distal axilliary arteries, whereas, 2D TOF sequences gave more limited coverage. Eight patients were found to have significant impingement (n=7) or stenosis (n=1) of the subclavian artery attributable to TOS. 3DCE MRA also demonstrated other relevant significant stenoses not attributable to TOS (n=5). All cases of impingement were either seen only, or more prominently, on sequences with the arms abducted. Reformatting the 3DCE MRA studies demonstrated the cause of impingement. CONCLUSIONS: Both 2D TOF and 3DCE MRA may demonstrate TOS with significant arterial impingement. In comparison with 2D TOF sequences, 3DCE MRA offers extensive vessel coverage, is less prone to artefact and frequently demonstrates the underlying cause of TOS when studies are reformatted. Evidence of impingement should be sought from sequences performed with the arms abducted and venous phase sequences may show corroborative venous impingement.

[Clinical attitudes toward periodontal risk]. / Attitudes cliniques face au risque parodontal.

After having defined the conditions that will start the loss of attached gingiva, the author develops the characteristic of the patient at periodontal risk. He then explains the value of the interview as well as that of the clinical and microbiological exams, insisting on the therapeutic outcome of those exams, and on the effect of the flora.

Effects of sanguinarium, chlorhexidine and tetracycline on neutrophil viability and functions in vitro.

The effectiveness of an ideal antimicrobial agent depends on its ability to kill microbes with minimal toxicity to host cells. Depending on the treatment regimen, antimicrobial agents come into contact with host cells for various intervals of time. Sanguinarium (SANG), chlorhexidine (CHX) and tetracycline (TET) are 3 antimicrobial agents frequently used in the management of periodontal infections. However, their effects on host immune cells during different treatment regimens are not known. Due to their ability to serve as the first line of host defense against microbial infections, we have compared the effects of these antimicrobial agents on human neutrophil functions and viability. The results show that SANG is not lytic to neutrophils from peripheral blood or crevicular fluid, at all concentrations tested. However, exposures of neutrophils to very low concentrations of SANG (0.001%) inhibits neutrophil chemotaxis, oxidative metabolism and degranulation within 5 min. Increasing the exposure time results in a similar inhibition of neutrophil functions, albeit at 50-100 fold lower concentrations of SANG. CHX rapidly disrupts the cell membrane of both crevicular and peripheral blood neutrophils at concentrations above 0.005% within 5 min, and inhibition of all neutrophil functions is due to its lytic properties. While TET is least toxic to neutrophils, a dose dependent inhibition of neutrophil functions is dependent on the calcium concentrations of the cellular environment, and is observed only above 0.04% or higher concentrations in the absence of calcium. The data suggest that a critical cumulative concentration of these drugs is essential for their toxicity and inhibition of neutrophil functions. Therefore, both the length of exposure and the dose of the drug both are critical while considering the effectiveness of SANG, CHX or TET in the treatment of infections. Furthermore, due to differences in their mechanisms of action, the consequences of their effects on neutrophils may have significant bearing on tissue pathology as well as on their therapeutic efficacy.

Characterization of sodium-dependent glucose transport in sheep tracheal epithelium.

The nonmetabolizable glucose analogue methyl(alpha-D-[U-14C]gluco)pyranoside ([14C]AMG) was used to study sodium-dependent glucose transport in two preparations: 1) discs punched from strips of sheep tracheal epithelium, and 2) freshly enzyme-isolated sheep tracheal epithelial cells. In discs, cellular accumulation of [14C]AMG was saturable and exhibited a Michaelis-Menten constant (Km) for AMG of 0.63 +/- 0.15 mM. Uptake was linear over 30 min and was inhibited maximally by 100 microM phlorizin [inhibition constant (Ki) approximately 20 nM], by replacement of external sodium with choline or by addition of 10 mM D-glucose (Ki = 0.19 +/- 0.02 mM). Accumulative uptake was activated, in a concentration-dependent manner, by external sodium [affinity constant (Ka) approximately 23 mM] with a Hill coefficient of greater than one but was abolished on depolarizing with high external potassium. In the presence of sodium, D-galactose and AMG both inhibited uptake of [14C]AMG, whereas L-glucose, D-fructose, and D-mannose were ineffective. In isolated cells, [14C]AMG accumulated only in the presence of external sodium and uptake was inhibited by the addition of D-glucose (Ki approximately 0.2 mM), D-galactose, and AMG but not by L-glucose or D-xylose. We conclude that sheep tracheal epithelium exhibits sodium-dependent glucose uptake with a very high affinity for phlorizin, which indicates the presence of a novel isoform of the transporter.

[Postoperative inhalation treatment after paranasal sinus interventions. A placebo-controlled, double-blind and randomized study]. / Postoperative Inhalationsbehandlung nach Nasennebenhöhleneingriffen. Eine plazebokontrollierte, doppelblinde und randomisierte Studie.

A placebo-controlled, double-blind study with Ems brine inhalations as postoperative treatment after endoscopic endonasal sinus surgery was conducted on 30 patients. After informed consent had been obtained, the patients were treated with either Ems brine or saline solution (200 ml) 3 times a day for 10 days. The parameters measured were rhinomanometry, X-ray films of the sinuses, endoscopy, saccharin clearance and a subjective evaluation by the physician and by the patient based on a visual analogue scale. The difficulty of choosing parameters for assessing the treatment was that comparable clinical studies and a single predictive parameter were not available. The bacteriological test and the saccharin clearance test were not significantly different between the two groups. Recovery, swelling, crusting, bleeding and signs of inflammation, opacity on sinus X-ray films, and nasal flow as measured by rhinomanometry were all significantly better in the group inhaling brine solution (P less than 0.05).

Polymorphonuclear neutrophil function in recurrent aphthous stomatitis.

Polymorphonuclear neutrophils (PMN) are the predominant cell type in the established lesion of recurrent aphthous stomatitis (RAS). The function of these cells was studied in 15 patients with RAS and 15 age and sex matched controls. Production of oxygen radicals was assessed using cytochrome-c and nitroblue tetrazolium dye (NBT) reduction assays. Oxidative metabolism was found to be similar for experimental and control groups in both stimulated and non-stimulated assays. Adherence to glass surfaces by PMN was also measured. Adherence of PMN, both from patients and controls, was significantly reduced by serum, but to a lesser extent by serum from patients compared to controls. This effect of serum on adherence was reversed by phorbol myristate acetate (PMA) stimulation. These studies suggest that increased adherence of stimulated PMN, due to humoral factors, may be involved in perpetuating ulcerative lesions in RAS.

The effect of sanguinarine on human peripheral blood neutrophil viability and functions.

Human polymorphonuclear cell (PMN) viability, morphology, adherence, chemotaxis, oxidative metabolism, degranulation and phagocytosis were evaluated following treatment with sanguinarine (SANG). SANG was noncytotoxic to PMNs at all concentrations tested (0.31-200 microM). SANG entered the PMNs rapidly without altering the membrane fluidity and localized in the nuclear matrix. SANG (1.56-6.21 microM) inhibited chemotaxis, chemokinesis and adhesion in a dose-dependent manner, with a complete inhibition at 6.2 microM concentration. Concentrations of SANG up to 1.56 microM did not affect PMN oxidative burst; however, higher concentrations were found to inhibit basal as well as PMA-induced superoxide anion generation. The effect of SANG was time- and dose-dependent, and could be reversed if the PMNs were exposed to 12.5 microM or lower concentrations of SANG for less than 5 min. Autologous serum increased the tolerance of PMNs to SANG. Exogenous Ca2+ or Mg2+ did not alter the SANG-mediated inhibition of PMN functions. Treatment of PMNs with 3.12 microM or higher concentrations of SANG also resulted in inhibition of PMN degranulation and phagocytosis. The results suggest that SANG-mediated inhibition of PMN functions, without cytolysis or resultant release of inflammatory mediators, may have clinical implications.

In vitro survival of Bacteroides intermedius in five transport media, alone or in the presence of Streptococcus sanguis.

The survival rate of Bacteroides intermedius was first tested in monoculture, and Streptococcus sanguis was then added in 5 different transport media; 2 nonnutritious media, the viability-preserving medium of the University of Göteborg No. IV (VMG IV), reduced transport fluid (RTF), and 3 nutritious media, thioglycolate medium (TG), peptone yeast extract medium (PY) and PY medium with 1% glucose (PYG). All manipulations were carried out in an anaerobic chamber. After a given transport time (6 or 24 h) aliquots were spread on plates containing solid PY medium by means of an automated spiral system device, thus permitting counts after incubation. The slight variations in the counts of B. intermedius in monoculture, not exceeding 0.5 log10 in the 5 media tested, indicated its good survival capability, i.e. at least 24 h. By contrast, when S. sanguis was added, it was only possible to use nutritious media such as PY or TG for 6 h. In the glocose-containing media (PYG, TG), the multiplication of rapidly glucose-fermenting microorganisms such as streptococci influenced the B. intermedius survival rate. Therefore, the transport time for oral microbiological samples needs to be reduced as much as possible. The use of excessively rich media (particularly media containing a high level of glucose) should be avoided.

[Immune response during experimental periodontitis in mice]. / Réponse immunitaire au cours des parodontitis expérimentales cehz la souris.

Four groups of mice, each of a different genotype, were orally inoculated with Actinomyces viscosus. The resulting periodontal bone loss was monitored and the isotype specific anti-A. viscosus serum humoral immune responses measured by ELISA. Maximum periodontal bone loss occurred in all genotypes with inoculation of 1.6 x 107 colony forming units of A. viscosus. IgG and IgM isotype levels increased with inoculation of 1.6 x 107 colony forming units of A. viscosus in three of the four groups, indicating that IgA may be important in producing periodontal bone loss.

[Mixed lymphocytic reaction in periodontal diseases]. / La réaction lymphocitaire mixte au cours des maladies parodontales.

The autologous mixed lymphocyte reaction is the in vitro expression of the regulation of the immune response. This article deals with the current knowledge of the subject and try to demonstrate that the mixed lymphocyte reaction is modified during some of the periodontal diseases.

[Iatrogenic interdental brushing. Apropos of a case]. / Le brossage interdentaire iatrogene. A propos d'un cas.

A case of severe dentinal abrasion most probably due to erroneous use of interproximal brushes is shown and discussed as well.

[Air polishing instruments. Review of literature]. / Les appareils aéropolisseurs. Revue de littérature.

The popularity of polishing air devices (AP) is rising with the increased distribution of commercial units in both United States and European dental offices and clinics. The instrument's efficiency and effectiveness in stain removal has been demonstrated with minimal impact on soft tissue trauma and abrasion. This article reviews the literature on AP. Future research is indicated to explore surgical clinical applications of airpowder polishing as well as more detailed information regarding the biological basis for its use.

[Current classification of periodontal diseases]. / Classification actuelle des maladies parodontales.

Since the last 15 years, tremendous progress have been made on epidemiology, microbiology, natural history, immunology, and periodontal tissue response to different treatment modalities. Thus, we are able to suggest today a relatively new classification of the different periodontal diseases far from the one based on the concept of "the periodontal disease". This article aims to help clinicians in understanding the classification of such diseases allowing better treatment and eventually better results.