Tooth substance loss resulting from mechanical, sonic and ultrasonic root instrumentation assessed by liquid scintillation

AIMS: This study investigated the loss of tooth substance (microg) by means of liquid scintillation in combination with profilometric and SEM analyses in order to evaluate the roughness and morphological changes of the root surface before and after instrumentation. METHOD: 40 polished and irradiated bovine root surfaces were scaled in vitro while covered with 50 ml distilled water using a sonic prototype (Periosonic 1/2), a magnetostrictive ultrasonic (Cavitron with Slimline inserts) scaler and a hand curette. Pressures were applied for the Periosonic, Cavitron and hand curette at 500, 500 and 30 g respectively, for 30-s intervals, up to 120 s. Loss of apatite (microg) was determined from the decays/min (32P) of the water samples using the radiochemical method of liquid scintillation. Replicas were made of the specimens for SEM and profilometric analyses. RESULTS: The least substance loss was noted significantly (p<0.01) at all time intervals after Slimline, followed by the fine sonic prototype Periosonic 2, then the Periosonic 1 and finally the hand curette. In contrast, profilometric and SEM analyses revealed the smoothest root surfaces after the hand curette, whereas Cavitron produced a less smooth surface. CONCLUSION: It can be concluded that this method can reveal very precisely small quantities of substance lost and, in combination with SEM analysis and microroughness measurements, be of considerable value in evaluating the aggressiveness and efficacy of periodontal instruments.     

Pharmacokinetics of acitretin and its 13-cis metabolite in patients on haemodialysis.

1. Plasma concentrations of acitretin and its metabolite (13-cis acitretin) were measured in six patients on haemodialysis and six subjects without renal failure following a single oral dose of 50 mg of acitretin. 2. The mean areas under the plasma concentration vs time curves of acitretin and its metabolite were about 50% lower in patients on haemodialysis. 3. No retinoids were detectable in the dialysate.     

Platelets in inflammation and atherogenesis

Platelets represent an important linkage between inflammation, thrombosis, and atherogenesis. Inflammation is characterized by interactions among platelets, leukocytes, and ECs. These interactions trigger autocrine and paracrine activation processes that lead to leukocyte recruitment into the vascular wall. Platelet-induced chronic inflammatory processes at the vascular wall result in development of atherosclerotic lesions and atherothrombosis. This Review highlights the molecular machinery and inflammatory pathways used by platelets to initiate and accelerate atherothrombosis.     

Adenosine stress cardiac magnetic resonance imaging for the assessment of ischemic heart disease

Aims  This prospective study was designed to determine the diagnostic value of adenosine stress cardiac magnetic resonance imaging (CMRI) in patients referred to elective coronary angiography. Methods and results  Myocardial perfusion measurements at rest and adenosine stress were performed in 141 patients (105 men, 36 women, mean age 63.4 years) at 1.5 T with a Turbo Flash sequence. Stress-induced perfusion deficits were correlated to angiographic stenoses ≥75%. The overall sensitivity for CMRI depicting coronary artery disease (CAD) with relevant stenoses was 90.4%, the specificity was 77.4%, the positive predictive value was 85.9%, the negative predictive value was 84.2% and the accuracy 85.2%. Subgroup analysis was performed for 3-vessel disease (n = 44, sensitivity 92.3%, specificity 75.0%), 2-vessel disease (n = 43, sensitivity 92.6%, specificity 92.9%), 1-vessel disease (n = 27, sensitivity 93.1%, specificity 71.4%) and patients without CAD (n = 27, specificity 70.4%) as well as for patients with prior myocardial infarction (n = 44, sensitivity 92.9%, specificity 86.7%), prior coronary artery bypass surgery (n = 21, sensitivity 88.2%, specificity 66.7%), prior coronary interventions (n = 88, sensitivity 91.9%, specificity 75.0%), or diabetics (n = 27, sensitivity 90.5%, specificity 83.3%). Conclusion  Our study shows that stress perfusion CMRI can accurately predict relevant CAD and contributes to the identification of hemodynamic relevant stenoses in patients scheduled for coronary angiography. C. Doesch and A. Seeger have equally contributed to this publication.     

Progressive abdominal pain in a 63‐year‐old man

50%–60% of patients with chronic mesenteric ischemia suffer from concomitant cardiovascular disease. We therefore suggest an extensive diagnostic screening to detect coronary artery and peripheral arterial disease in these patients.