Comparison between five commonly used two-dimensional methods of human bite mark overlay production from the dental study casts.

Aim: The present study was conducted to determine the most accurate bite mark overlay fabrication technique by studying two physical characteristics, i.e., area and rotation of biting edges of anterior teeth of thirty volunteers. The objective of the study was to evaluate the reliability and efficacy of five commonly used methods of human bite mark overlays using two dimensional (2D) digital images of dental study casts as a gold standard, to rank different methods according to statistically based determination of relative accuracy of each method and to determine its feasibility in Forensic science. Materials and Methods: Overlays were produced from the biting surfaces of six upper and six lower anterior teeth of 30 volunteers using the following five methods: a) hand tracing from study casts, b) hand tracing from wax impressions, c) xerographic method, d) radiopaque impression method and e) 2D computer-based method. Area of the biting edges of the anterior teeth and relative rotation of each anterior tooth were measured and compared. Results: The xerographic method was determined to be the more accurate method with respect to tooth area and rotation. Hand tracing methods, from either wax impressions of teeth or directly from study casts, were determined to be inaccurate and subjective. Conclusions: It is recommended that forensic odontologists discontinue the use of hand tracing overlays in bite mark comparison cases as there is lot of scope for manipulation and observer bias.

Congestive heart failure in unoperated tetralogy of Fallot: can hypoxia be a cause?

A 10-year-old boy with tetralogy of Fallot and congestive heart failure underwent a right-sided modified Blalock-Taussig anastomosis because of severe biventricular dysfunction and repeated hypercyanotic spells. Postoperatively, there was improvement in systemic oxygen saturation and myocardial function. We postulate that congestive heart failure occurred because of severe myocardial hypoxia and its elimination resulted in markedly improved cardiac performance.

Surgical outcome of staged univentricular-type repairs for patients with univentricular physiology and pulmonary hypertension.

BACKGROUND: There is no consensus about the most appropriate limits of pulmonary artery pressure and vascular resistance in case of patients undergoing univentricular or one and one-half ventricular repair. This study was conducted to analyze the mortality and morbidity of a heterogenous group of patients with a functionally univentricular heart and pulmonary artery hypertension, undergoing pulmonary artery banding followed by univentricular-type repairs. METHODS AND RESULTS: Out of 254 patients undergoing pulmonary artery banding for a functionally univentricular heart with increased pulmonary blood flow, 148 patients underwent definitive second stage surgery. Post-band hemodynamic evaluation revealed persistently high pulmonary artery pressure (> 18 mmHg), and pulmonary vascular resistance (>2.0 Woods units/m2) in 78.3% patients. Sixteen patients with moderate right ventricular hypoplasia were given a one and one-half ventricle repair (Group I), 82 patients a bidirectional Glenn connection (Group II), and 50 patients a fenestrated total cavopulmonary connection (Group III). The overall mortality following second stage surgery for the high pulmonary artery pressure group (n=116) was 30.17%, while none of the low pulmonary artery pressure group died (p=0.0009). Pulmonary hypertensive crises and/or systemic desaturation were the main causes of death at second stage repair. All mortality occurred in patients with mean pulmonary artery pressure > 18 mmHg and pulmonary vascular resistance > 3.5 Woods units/m2. Survivors from this group had persistent morbidity in the form of superior vena caval syndrome and suboptimal oxygen saturation (70-75%). CONCLUSIONS: It is advisable not to proceed with definitive second stage repair if post-pulmonary artery banding mean pulmonary artery pressure is over 25 mmHg and pulmonary vascular resistance exceeds 4.0 Woods units/m2. These patients may possibly be deemed to have undergone definitive palliation during their pulmonary artery banding.

Validation of ELISA test kits for detection of beta-agonist residues in meat.

Three ELISA test kits, the Randox ELISA beta-agonist test kit, Euro-Diagnostica test kit, and Ridascreen beta-agonist test kit, were evaluated for screening of meat and liver for beta-agonist residues in fortified and field-incurred samples. It was found that the Randox beta-agonist test kit was more suitable as a screening tool due to its accuracy, ease of use, and lower cost. The tests were able to detect beta-agonist residues at the minimum level of detection, as claimed by the suppliers. The performance of the method as assessed through recovery rates of beta-agonists in fortified samples was satisfactory with a low coefficient of variation (1-3%). Repeatability, as measured through the coefficient of correlation was also satisfactory. For field-incurred positive samples, the test kit showed a sensitivity of 100% and a low rate of false positives for goat and cow tissues. However, a high rate of apparent false positives was obtained for tissues of swine.