Method for determination of root curvature radius using cone-beam computed tomography images

This article describes and discusses a method to determine root curvature radius by using cone-beam computed tomography (CBCT). The severity of root canal curvature is essential to select instrument and instrumentation technique. The diagnosis and planning of root canal treatment have traditionally been made based on periapical radiography. However, the higher accuracy of CBCT images to identify anatomic and pathologic alterations compared to panoramic and periapical radiographs has been shown to reduce the incidence of false-negative results. In high-resolution images, the measurement of root curvature radius can be obtained by circumcenter. Based on 3 mathematical points determined with the working tools of Planimp(R) software, it is possible to calculate root curvature radius in both apical and coronal directions. The CBCT-aided method for determination of root curvature radius presented in this article is easy to perform, reproducible and allows a more reliable and predictable endodontic planning, which reflects directly on a more efficacious preparation of curved root canals.     

Introducing systematic dispatcher-assisted cardiopulmonary resuscitation (telephone-CPR) in a non-Advanced Medical Priority Dispatch System (AMPDS): Implementation process and costs

Objective

In order to improve the quality of our Emergency Medical Services (EMS), to raise bystander cardiopulmonary resuscitation rates and thereby meet what is becoming a universal standard in terms of quality of emergency services, we decided to implement systematic dispatcher-assisted or telephone-CPR (T-CPR) in our medical dispatch center, a non-Advanced Medical Priority Dispatch System. The aim of this article is to describe the implementation process, costs and results following the introduction of this new “quality” procedure.

Methods

This was a prospective study. Over an 8-week period, our EMS dispatchers were given new procedures to provide T-CPR. We then collected data on all non-traumatic cardiac arrests within our state (Vaud, Switzerland) for the following 12 months. For each event, the dispatchers had to record in writing the reason they either ruled out cardiac arrest (CA) or did not propose T-CPR in the event they did suspect CA. All emergency call recordings were reviewed by the medical director of the EMS. The analysis of the recordings and the dispatchers’ written explanations were then compared.

Results

During the 12-month study period, a total of 497 patients (both adults and children) were identified as having a non-traumatic cardiac arrest. Out of this total, 203 cases were excluded and 294 cases were eligible for T-CPR. Out of these eligible cases, dispatchers proposed T-CPR on 202 occasions (or 69% of eligible cases). They also erroneously proposed T-CPR on 17 occasions when a CA was wrongly identified (false positive). This represents 7.8% of all T-CPR.No costs were incurred to implement our study protocol and procedures.

Conclusions

This study demonstrates it is possible, using a brief campaign of sensitization but without any specific training, to implement systematic dispatcher-assisted cardiopulmonary resuscitation in a non-Advanced Medical Priority Dispatch System such as our EMS that had no prior experience with systematic T-CPR. The results in terms of T-CPR delivery rate and false positive are similar to those found in previous studies. We found our results satisfying the given short time frame of this study.Our results demonstrate that it is possible to improve the quality of emergency services at moderate or even no additional costs and this should be of interest to all EMS that do not presently benefit from using T-CPR procedures.EMS that currently do not offer T-CPR should consider implementing this technique as soon as possible, and we expect our experience may provide answers to those planning to incorporate T-CPR in their daily practice.     

Release of cell-free DNA into the bloodstream leads to high levels of non-tumor plasma DNA during tumor progression in rats

To examine the implications of cell-free DNA in the plasma in neoplastic disease, it is necessary to clarify various features of this DNA, such as the contribution of DNA from the host's normal cells and the kinetics of the release of this latter DNA. To quantify non-tumor DNA in the plasma of tumor-bearing rats and to correlate levels of this DNA with tumor progression, we injected DHD/K12-PROb colon cancer cells subcutaneously into BD-IX rats and recorded tumor diameters weekly. After euthanasia, we collected plasma from each rat and quantified non-mutated and mutated DNA in the plasma. Overall, levels of non-mutated (non-tumor) DNA in plasma of tumor-bearing animals were significantly higher than those in healthy animals measured by real-time PCR (p=0.001). However, 5 weeks after inoculation, levels were similar to those in healthy animals. As a whole, levels of non-mutated DNA were not significantly related to tumor size or to metastasis. However, when we excluded animals that were analyzed earliest, we found a positive and statistically significant correlation between levels of non-mutated DNA and tumor diameter (p=0.002). Release of cell-free DNA into the plasma during tumor progression appears to follow a predictable time course in a homogeneous population. In addition, large amounts of non-tumor DNA are released during tumor progression and, in particular, at early stages. Our findings support the hypothesis that interactions between tumor cells and host cells result in release of cell-free DNA.     

Bioluminescence inhibition assays for toxicity screening of wood extractives and biocides in paper mill process waters

The risk associated with wood extractives, biocides, and other additives in pulp and paper mill effluents was evaluated by performing a characterization of process waters and effluents in terms of toxicity and chemical analysis. The individual toxicity of 10 resin acids, two unsaturated fatty acids, and three biocides was estimated by measuring the bioluminescence inhibition with a ToxAlert 100 system. Median effective concentration values (EC50) of 4.3 to 17.9, 1.2 to 1.5, and 0.022 to 0.50 mg/L were obtained, respectively. Mixtures of these three families of compounds showed antagonistic effects. Chemical analysis of process waters was performed by liquid chromatography- and gas chromatography-mass spectrometry. Biocides such as 2-(thiocyanomethylthio)-benzotiazole (TCMTB) (EC50 = 0.022 mg/L) and 2,2-dibromo-3-nitrilpropionamide (DBNPA) (EC50 = 0.50 mg/L) were the most toxic compounds tested and were detected at concentrations of 16 and 59 microg/L, respectively, in a closed-circuit recycling paper mill. Process waters from kraft pulp mills, printing paper mills, and packing board paper mills showed the highest concentration of resin acids (up to 400 microg/L) and accounted for inhibition percentages up to 100%. Detergent degradation products such as nonylphenol (NP) and octylphenol (OP) and the plasticizer bisphenol A (BPA) were also detected in the waters at levels of 0.6 to 10.6, 0.3 to 1.4, and 0.7 to 187 microg/L, respectively. However, once these waters were biologically treated, the concentration of detected organic compounds diminished and the toxicity decreased in most cases to values of inhibition lower than 20%.     

The vascular smooth muscle of great arteries: local control site of arterial buffering function?

INTRODUCTION AND OBJECTIVES: To characterize the viscoelastic properties of the aorta and pulmonary arteries and the effects of vascular smooth muscle activation on arterial buffering function. MATERIAL AND METHOD: Aortic and pulmonary artery pressure and diameter were measured in six anesthetized sheep under baseline conditions, and during arterial hypertension induced by mechanical vascular occlusion (passive), and i.v. phenylephrine (active). Arterial wall elasticity and viscosity were calculated, and buffering function was characterized: a) locally as the viscosity/elasticity ratio, and b) globally for each circuit, as the time-constant of ventricular relaxation. RESULTS: Viscoelasticity was higher in the aorta than in the pulmonary artery (p < 0.05), however, parietal buffering function was similar in both. Global buffering function was highest in the systemic circuit (p < 0.05). During passive hypertension, elasticity was significantly increased with no change in viscosity; this led to a significant reduction in local buffering function, and in global buffering function in each circuit. During active hypertension, viscosity increased (p < 0.05), while local and global buffering functions returned to baseline values. CONCLUSIONS: The viscosity/elasticity ratio was higher in the aorta than in the pulmonary artery, and arterial wall buffering function was similar in both vessels. Systemic global buffering function was higher than pulmonary circuit buffering function. Elasticity depends on intravascular pressure, whereas viscosity is a marker of the degree of smooth muscle activation. Smooth muscle activation may benefit the cardiovascular system by maintaining local and global buffering functions.     

Celiac disease in Brazilian adults

Forty-eight adult patients with celiac disease between 15 and 68 years of age (mean, 41 years) were studied. Sixty-seven percent were female and 33% were male patients. Most of the patients were white (98%). The main clinical features were diarrhea (90%), weight loss (70%), and abdominal pain (56%). On physical examination, the main findings were pallor (40%), aphthous stomatitis (31%), and arthralgia (23%). Associated disorders included diabetes mellitus type I, osteoporosis, and atopy (6% each); dermatitis herpetiformis and depression (4% each); and hypothyroidism, hyperthyroidism, duodenal carcinoma, and Gilbert syndrome (2% each). The histologic results according to Marsh criteria (modified by Rostami) are as follows: type I, 10%; type II, 21%; type IIIa, 19%; type IIIb, 17%; and type IIIc, 33%. The sensitivity and specificity for the antiendomysium antibody-immunoglobulin A test were 92% and 100%, respectively, when considering the whole group of patients; however, the sensitivity (but not the specificity) decreased to 86% when taking into account only the group of patients with mild histologic alterations (Marsh type I, II, and IIIa).CONCLUSION: In general, the authors' results are similar to those described in developing countries, indicating that celiac disease might have the same spectrum of presentation regardless of the region studied.     

Fluoroscopic cardiac anatomy for catheter ablation of tachycardia

The understanding of cardiac anatomy is crucial for the interventional arrhythmologist. In spite of the introduction of several nonfluroscopic navigational tools, some of them capable of reconstructing a computer-based surrogate of the endocardial surface of the heart cavities, simple fluoroscopy with or without the aid of angiographic techniques is still the most widely used method to guide mapping and ablation procedures. In some instances, fluoroscopic and angiographic methods have no possible replacement to unravel certain arrhythmologically useful anatomic landmarks. New interpretations of cardiac architecture show the need to challenge some traditional anatomic views, like the concept of septums within the heart. The fluoroscopic anatomy also needs to be reconsidered in the light of the new attitudinally oriented nomenclature. This article presents an overview of the fluoroscopic anatomy of the heart. When pertinent, some anatomical concepts are discussed in more detail like the triangle of Koch, the pyramidal space, and the interatrial groove. In the sections on the atria and on the ventricles, the authors focus on the anatomic information that is relevant for mapping and ablation from a fluoroscopic viewpoint, providing some hints on how best to depict the morphological features from the stance of the interventional arrhythmologist. The Visible Human Slice and Surface Server using data sets from the Visible Human Male and Female Project, has been used to facilitate the understanding of the fluoroscopic anatomy.