Evaluation of ECG algorithms designed to improve detect of transient myocardial ischemia to minimize false alarms in patients with suspected acute coronary syndrome

Background

Patients hospitalized for suspected acute coronary syndrome (ACS) are at risk for transient myocardial ischemia. During the “rule-out” phase, continuous ECG ST-segment monitoring can identify transient myocardial ischemia, even when asymptomatic. However, current ST-segment monitoring software is vastly underutilized due to false positive alarms, with resultant alarm fatigue. Current ST algorithms may contribute to alarm fatigue because; (1) they are not designed with a delay (minutes), rather alarm to brief spikes (i.e., turning, heart rate changes), and (2) alarm to changes in a single ECG lead, rather than contiguous leads.

Diagnostic role of an immunoassay-detected polymorphism of factor IX for potential carriers of hemophilia B

In hemophilia B, assays based on a monoclonal antifactor IX specific for the Thr-148 variant of an exonic polymorphism have diagnosed carriers in selected families by either establishing linkage or by indicating the presence or absence of a given normal factor IX. The sensitivity of the immunoassays for detecting heterozygous women was explored by comparing results from immunoassays with solid-phase polyclonal v the monoclonal antifactor IXs. Factor IX with the normal Ala-148 variant gave a flat dilution curve, qualitatively distinct from factor IX with the Thr-148 variant in the monoclonal assay. The two were indistinguishable in the polyclonal assay. Mixtures of equal amounts of the two types gave an intermediate result, about half as reactive in the monoclonal as compared with the polyclonal assay system. Whereas mixtures with 10% Ala-148 and 90% Thr-148 factor IXs could not readily be distinguished from Thr-148 factor IX plasma, as little as 1% of the Thr-148 protein was detected in Ala-148 factor IX plasma. The frequency of the Ala-148 variant varied in individuals with different ethnic backgrounds; it was found in 29% of white, 12% of black, and none of Asian blood donors' factor IX genes in Seattle. Only 4% of samples from South African black men were nonreactive (ie, Ala- 148). The Thr/Ala-148 dimorphism is in strong linkage disequilibrium with Taql restriction fragment length polymorphisms (RFLPs). Three recombinations were noted in normal white genes and one in a normal black factor IX gene (less than 2% of those examined). In 34 white families with at least one woman being a possible carrier, genetically, the immunoassay results were informative in 18. RFLP analyses were informative in eight of the 15 families tested. In five families each, assignment of carrier status was made to a woman by only DNA or only immunoassay results, whereas the other approach was noninformative. The immunoassays provide a rapid, inexpensive screening test and complement DNA analysis in white women who are potential carriers of hemophilia B.     

Kinematics of 2 Reciprocating Endodontic Motors: The Difference between Actual and Set Values

Introduction

The aim of this study was to evaluate the kinematics of 2 reciprocating motors and compare it with manufacturers' declared values.

Methods

VDW Silver (VDW, Munich, Germany) and ATR Tecnika (Tecnika, Pistoia, Italy) were used in the study in 5 working modes: continuous rotation at 400 rpm on VDW Silver and ATR Tecnika and reciprocating motion on ATR Tecnika at 400 rpm and on VDW Silver in Reciproc and WaveOne mode. The polishing disk with an optical target was inserted in the contra-angle and recorded with a 1000–frames per second video camera. The direction and the amount of rotation were analyzed by computer, and the following kinematics parameters were calculated: engaging and disengaging angles, cycle rotational speeds, engaging and disengaging rotational speeds, net cycle angle, total cycle angle, and number of cycles to complete full rotation. One-way analysis of variance followed by planned pair-wise comparisons was used to compare kinematics parameters. The alpha error was set to 0.05.

Results

Analysis of variance revealed a difference between actual and set values of all 3 reciprocating modes in all kinematics parameters (P < .001). No significant difference between the actual engaging angle of Reciproc and that of the WaveOne mode was found. For reciprocating motion on the ATR Tecnika at 400 rpm, the actual engaging and disengaging angles were 8- and 9-fold greater, respectively, compared with set angles (P < .001).

Conclusions

The kinematics of reciprocating instrumentation is more complex than it seems as described only with angles and rotational speed. Actual kinematics values differ from manufacturers' declared values.     

Prevention of graft-versus-host disease by a novel immunosuppressant, PG490-88, through inhibition of alloreactive T cell expansion

BACKGROUND: PG490-88 is a water soluble, semisynthetic derivative of a novel compound PG490 (triptolide) purified from the Chinese herb Tripterygium Wilfordii Hook F. METHODS: PG490-88 was administrated into recipient mice in a model (B10.D2-->BALB/c) of lethal graft-versus-host disease (GVHD) to study the effects of PG490-88 on GVHD and on the various steps involved in the pathological course of GVHD. RESULTS: Injection of PG490-88 i.p. at a dose of 0.535 mg/kg/day for the first 3 weeks after transplantation protected all the recipients from developing GVHD up to 100 days after transplantation. PG490-88 inhibited in vivo both CD4+Vbeta3+ and CD8+Vbeta3+ T cell (alloreactive T cells in this model) expansion in the spleen by 64.09 and 34.02%, respectively, at the time when Vbeta3+ cell expansion was in the logarithmic phase (day 3 after transplantation). Intracellular cytokine staining without further in vitro activation demonstrated 47.42% inhibition of IL-2 production among CD4+ spleen cells in PG490-88-treated mice as compared to GVHD control on day 3 after transplantation. In contrast, CD25 (alpha chain of interleukin-2 receptor) expression did not differ. CONCLUSIONS: PG490-88 is highly effective in prevention of murine GVHD. The immunosuppressive effect of PG490-88 is mediated by inhibition of alloreactive T cell expansion through interleukin-2 production.     

New concepts in intestinal imaging for inflammatory bowel diseases

In the last decade, multiple imaging technologies have been developed that improve visualization of the mucosal, mural, and perienteric inflammation associated with inflammatory bowel diseases. Whereas these technologies have traditionally been used to detect and stage suspected enteric inflammation, we review new, emerging roles in detecting clinically occult inflammation (in asymptomatic patients) and inflammatory complications, predicting response prior to therapy, assessing response after therapy, and enteric healing. We compare the relative performance of these technologies in detecting inflammation, focusing on their advantages and disadvantages and how they might complement each other. We also discuss their potential benefits for patients and clinical trials, reviewing technologic developments and areas of research that could provide important insights into the pathophysiology of inflammatory bowel diseases-related enteric inflammation.     

Prognostic Significance of Skeletal Muscle Loss During Early Postoperative Period in Elderly Patients with Esophageal Cancer

Annals of Surgical Oncology -     

A prospective evaluation of computerized tomographic (CT) scanning as a screening modality for esophageal varices

Patients with cirrhosis require endoscopic screening for large esophageal varices. The aims of this study were to determine the cost-effectiveness and patient preferences of a strategy employing abdominal computerized tomography (CT) as the initial screening test for identifying large esophageal varices. In a prospective evaluation,102 patients underwent both CT and endoscopic screening for gastroesophageal varices. Two radiologists read each CT independently; standard upper gastrointestinal endoscopy was the reference standard. Agreement between radiologists, and between endoscopists regarding size of varices was determined using kappa statistic. Cost-effectiveness analysis was performed to determine the optimal screening strategy for varices. Patient preference was assessed by questionnaire. CT was found to have approximately 90% sensitivity in the identification of esophageal varices determined to be large on endoscopy, but only about 50% specificity. The sensitivity of CT in detecting gastric varices was 87%. In addition, a significant number of gastric varices, peri-esophageal varices, and extraluminal pathology were identified by CT that were not identified by endoscopy. Patients overwhelmingly preferred CT over endoscopy. Agreement between radiologists was good regarding the size of varices (Kappa = 0.56), and exceeded agreement between endoscopists (Kappa = 0.36). Use of CT as the initial screening modality for the detection of varices was significantly more cost-effective compared to endoscopy irrespective of the prevalence of large varices. CONCLUSION: Abdominal CT as the initial screening test for varices could be cost-effective. CT also permits evaluation of extra-luminal pathology that impacts management.