Plate osteosynthesis of the mandibular condyle

The aim of this study is to evaluate and compare the biomechanical stability of various osteosynthesis materials for mandible condylar-process fractures. On 160 porcine mandibles, four different monocortical plating techniques (40 per group) were investigated. Condyles were fractured at a defined location from the incisure to the posterior border. After correct anatomical reduction the fractures were plated, using four different techniques. Osteosynthesis materials used were the delta plate, the trapezoid plate, the dynamic compression plate and double mini-plates. Each group was subjected to linear loading in lateral to medial, medial to lateral, anterior to posterior and posterior to anterior directions by a universal mechanical testing machine TIRAtest 2720. Yield load, yield displacement were measured for the different plates. Statistically significant differences were noted between the fixation groups in all four directions. Rigid internal fixation with double mini plates showed the best stability in all directions except posterior to anterior. In this direction, the delta-plate resisted the highest loads. In the three other directions, the delta plate was second best with data similar to double miniplates but lower in magnitude.     

A simulation of hand impairments: Effects on upper extremity function and implications toward medical impairment rating and disability determination

Objectives: To determine whether simulation of significant impairment of the hand will have a predictable impact on degree of functional loss at the wrist and hand.Design: Single subject repeat measures using before-after trial comparisons and healthy volunteer subjects.Setting: Occupational therapy section of a large academic medical center.Other Participants: Twenty adult volunteer student subjects from an occupational therapy education (OTE) department were included. All were between ages 18 and 43 years, right hand dominant, and in excellent general health. There were 19 women and 1 man, reflecting gender distribution of the OTE student body.Intervention: A simulated fusion of the carpometacarpal (CMC) joint of the thumb was achieved by immobilization in an individually fabricated splint designed to maximally restrict motion at the first CMC joint. Impairment ratings (baseline vs splinted) according to the AMA Guides were obtained by Greenleaf testing, and upper extremity function was quantitatively assessed before and after splinting.Main Outcome Measures: Measures of upper extremity function included grip and pinch strength, wrist torque, and speed of performance on the Valpar Small Tools test, Jebsen Hand Function test, and an exploratory measure, the Functional Life Activity Test (FLAT).Results: Significant impairments were achieved for all subjects after splinting and according to Greenleaf testing. Splinting resulted in significant reductions in grip and pinch strength, wrist torque, and significant slowing of performance on the Valpar, Jebsen, and FLAT tests. Regressions of degree of impairment on degree of functional loss after splinting, and according to each of the above measures, were not significant.Conclusions: Impairment of the hand was simulated to a mild-to-moderate degree as measured according to the AMA Guides. This imposed significant reductions in motion at key joints of the wrist and hand as well as significant reductions in grip and pinch strength and wrist torque. A corresponding and significant slowing of performance on a variety of measures of upper extremity function of an industrial and nonindustrial nature was also seen. However, and for the first time, correlation and regression reveals that it is not possible to predict degree of functional loss attributable to degree of impairment for the hand. It thus appears that, for mild-to-moderate clinical impairments, the associated impairment rating is a poor estimator of functional loss at the hand and should be used cautiously, if at all, as a criterion for disability determination.     

Enhancement of T helper type 1 immune responses against hepatitis B virus core antigen by PLGA nanoparticle vaccine delivery.

Currently, there is a need for therapeutic vaccines that are effective in inducing robust T helper type 1 (Th1) immune responses capable of mediating viral clearance in chronic hepatitis B infection. Hepatitis B therapeutic vaccines were designed and formulated by loading the hepatitis B core antigen (HBcAg) into poly(D,L-lactic-acid-co-glycolic acid) (PLGA) nanoparticles with or without monophospholipid A (MPLA), a Th1-favoring immunomodulator. These particles were around 300 nm in diameter, spherical in shape and had approximately 50% HBcAg encapsulation efficiency. A single immunization with a vaccine formulation containing (MPLA+HBcAg) coformulated in PLGA nanoparticles induced a stronger Th1 cellular immune response with a predominant interferon-gamma (IFN-gamma) profile than those induced by HBcAg alone, free (HBcAg+MPLA) simple mixture or HBcAg-loaded nanoparticles in a murine model. More importantly, the level of HBcAg-specific IFN-gamma production could be increased further significantly by a booster immunization with the (HBcAg+MPLA)-loaded nanoparticles. In summary, these results demonstrated that codelivery of HBcAg and MPLA in PLGA nanoparticles promoted HBcAg-specific Th1 immune responses with IFN-gamma production. These findings suggest that appropriate design of the vaccine formulation and careful planning of the immunization schedule are important in the successful development of effective HBV therapeutic vaccines.     

Evaluation of Ion Torrent sequencing technology for rapid clinical human leucocyte antigen typing

The development of techniques to define the human leucocyte antigen (HLA) region has proven to be challenging due to its high level of polymorphism. Within a clinical laboratory, a technique for high‐resolution HLA typing, which is rapid and cost effective is essential. NGS has provided a rapid, high‐resolution HLA typing solution, which has reduced the number of HLA ambiguities seen with other typing methods. In this study, the One Lambda NXType NGS kit was tested on the Ion Torrent PGM platform. A total of 362 registry donors from four ethnic populations (Europeans, South Asians, Africans and Chinese) were NGS HLA typed across 9‐loci (HLA‐A, ‐B, ‐C, ‐DRB1,‐DRB345 ‐DQB1 and ‐DPB1). Concordance rates of 91%–98% were obtained (for HLA‐A, ‐B, ‐C, ‐DRB1, ‐DQB1 and ‐DPB1) when compared to historical PCR‐SSO HLA types, and the identification of uncommon alleles such as A*24:07:01 and C*04:82 were observed. A turnaround time of four days was achieved for typing 44 samples. However, some limitations were observed; primer locations did not allow all ambiguities to be resolved for HLA Class II where Exon I and IV amplification are needed (HLA‐DRB1*04:07:01/04:92, HLA‐DRB1*09:01:02/*09:21 and HLA‐DRB1*12:01:01/*12:10). This study has demonstrated high‐resolution typing by NGS can be achieved in an acceptable turnaround time for a clinical laboratory; however, the Ion Torrent workflow has some technical limitations that should be addressed.     

Acute diverticulitis in renal transplant patients: should we treat them differently?

Background

Current guidelines suggest that transplant patients with acute diverticulitis should be managed aggressively with early operative intervention to reduce morbidity and mortality. This study compared the treatment choices and clinical outcomes between renal transplant patients and immunocompetent patients with acute diverticulitis.

Ablation of nonsustained or hemodynamically unstable ventricular arrhythmia originating from the right ventricular outflow tract guided by noncontact mapping

Conventional activation or pacemapping is effective in guiding ablation of ventricular tachyarrhythmia originating from right ventricular outflow tract (RVOT). However, in selected patients with hemodynamically unstable or nonsustained tachycardia, noncontact mapping may be an effective alternative method to guide ablation in RVOT. Five patients with symptomatic hypotension during ventricular tachycardia (VT) or nonsustained tachyarrhythmia originating from the RVOT had radiofrequency ablation guided by noncontact mapping. All patients had a history of syncope and the tachyarrhythmias were refractory to antiarrhythmic therapy. Four patients had spontaneous sustained VT of a cycle length from 250 to 300 ms and one had symptomatic ventricular ectopic beats. Two patients were diagnosed to have arrhythmogenic right ventricular cardiomyopathy (ARVC). Sustained VT with hypotension was induced in two patients and nonsustained VT in three patients. Isopotential color maps were used to locate the earliest activation site of the tachyarrhythmia in RVOT. Three patients had tachyarrhythmia exit sites at the septal region and two at lateral region of RVOT. Low voltage area and diastolic activity were detected in the two patients with ARVC. Radiofrequency ablation guided by noncontact mapping was performed during sinus rhythm in all patients. The number of ablation attempts ranged from 1 to 14. After follow-up for 12 +/- 5.8 months, there was no recurrence of tachyarrhythmia and syncope in all five patients. Noncontact mapping is a safe and effective alternative method to guide ablation of hemodynamically unstable or nonsustained ventricular arrhythmia originating from RVOT.