Performance evaluation of a dental handpiece in simulation of clinical finishing using a novel 2DOF in vitro apparatus.

This paper reports on the performance evaluation of a dental handpiece in simulation of clinical finishing using a novel two-degrees-of-freedom (2DOF) in vitro apparatus. The instrumented apparatus consisted of a two-dimensional computer-controlled coordinate worktable carrying a dental handpiece, a piezoelectric force dynamometer, and a high-speed data acquisition and signal conditioning system for simulating the clinical operations and monitoring the dental finishing processes. The performance of the dental handpiece was experimentally evaluated with respect to rotational speed, torque, and specific finishing energy under the applied clinical finishing conditions. The results show that the rotational speeds of the dental handpiece decreased by increasing either the depth of cut or the feed rate at a constant clinically applied air pressure and water flowrate. They also decreased when increasing both the tangential and normal finishing forces. The specific finishing energy decreased with an increase in either depth of cut or feed rate, while the finishing torque increased as either the depth of cut or the feed rate was increased. Implications of these results were to provide guidance for proper applications of dental handpieces in clinical practice.

Artemether administered together with haemin damages schistosomes in vitro.

We conducted experiments in vitro to assess the effect of artemether in combination with haemin on adult Schistosoma japonicum, S. mansoni and S. haematobium. When schistosomes were maintained in a medium containing artemether at concentrations of 20 micrograms/mL or less for 72 h, no apparent effect on the schistosomes was seen. When the medium contained 50 or 100 micrograms/mL haemin as well as artemether, the schistosomes showed decreased motor activity 2-24 h after exposure, which was followed by the staining of the whole worm body a reddish-yellow colour, dilatation of the intestine, and extensive vesiculation of the tegument. Some of the schistosomes died 24 h after exposure, and almost all died within 48-72 h. When schistosomes were exposed to the same concentrations of haemin alone, they were stained a light yellow colour but there was no apparent effect on their survival. Our findings suggest that artemether interacts with haemin to exert a toxic effect on the worms, which might be of importance in the further elucidation of the mechanism of action of artemether on schistosomes.

Periodontal infection profiles in type 1 diabetes.

OBJECTIVES: We investigated the levels of subgingival plaque bacteria and serum IgG responses in patients with type 1 diabetes and non-diabetic controls of comparable periodontal status. MATERIAL AND METHODS: Fifty type 1 diabetes patients (mean duration 20.3 years, range 6-41) were age-and gender-matched with 50 non-diabetic individuals with similar levels of periodontal disease. Full-mouth clinical periodontal status was recorded, and eight plaque samples/person were collected and analysed by checkerboard hybridization with respect to 12 species. Homologous serum IgG titres were assessed by checkerboard immunoblotting. In a sub-sample of pairs, serum cytokines and selected markers of cardiovascular risk were assessed using multiplex technology. RESULTS: Among the investigated species, only levels of Eubacterium nodatum were found to be higher in diabetic patients, while none of the IgG titres differed between the groups, both before and after adjustments for microbial load. Patients with diabetes had significantly higher serum levels of soluble E-selectin (p=0.04), vascular cell adhesion molecule-1 (VCAM-1; p=0.0008), adiponectin (p=0.01) and lower levels of plasminogen activator inhibitor-1 (PAI-1; p=0.02). CONCLUSIONS: After controlling for the severity of periodontal disease, patients with type 1 diabetes and non-diabetic controls showed comparable subgingival infection patterns and serum antibody responses.

Percutaneous mitral valvuloplasty with a single rubber-nylon balloon (Inoue balloon): long-term results in 71 patients.

The first 71 patients with rheumatic mitral stenosis who successfully underwent single rubber-nylon balloon (Inoue balloon) percutaneous mitral valvuloplasty (PMV) from November 1985 to August 1988 had a mean follow-up period of 27.1 +/- 11.6 months (range, 14 to 48 months). Functional status before PMV was New York Heart Association (NYHA) functional class IV in two, class III in 38, and class II in 31. Pre and post PMV and follow-up mean diastolic mitral gradient by catheter method was 17.5 +/- 6.9, 2.7 +/- 3.5, and 3.3 +/- 3.4 mm Hg (p less than 0.001 pre versus post PMV and pre PMV versus follow-up; and p greater than 0.005 post PMV versus follow-up). By Doppler method the mean diastolic gradient was 17.4 +/- 5.5, 8.5 +/- 4.7, and 9.2 +/- 4.1 mm Hg, respectively (p less than 0.001 pre versus post PMV and pre PMV versus follow-up; and p greater than 0.05 post PMV versus follow-up). Mitral valve area was 1.12 +/- 0.26, 2.04 +/- 0.41, and 1.92 +/- 0.45 cm2, respectively (p greater than 0.001 pre versus post PMV and pre PMV versus follow-up; and p less than 0.05 post PMV versus follow-up). The phonocardiographic and vectorcardiographic studies and cardiopulmonary exercise testing showed significant improvement after PMV and at follow-up. At follow-up the NYHA functional class was 1 in 57 patients, class II in 13, and class III in one patient with severe mitral valve calcification and subvalvular fusion, in whom restenosis occurred 18 months after PMV.(ABSTRACT TRUNCATED AT 250 WORDS)