Retrograde transneuronal transfer of the C-fragment of tetanus toxin

The transport of the C-fragment of tetanus toxin after intramuscular injection was studied with immunohistochemical techniques. Brainstems and spinal cords of mice were examined after injections of C-fragment into the tongue or forearm. Labelled motorneurons were observed within 6 h. By two days after injection, the bulk of detectable C-fragment had passed out of motorneurons into the surrounding neuropil. C-fragment, like native tetanus toxin, appears to be transferred from motorneurons to presynaptic structures to an extent not observed with other proteins. It is useful in the study of retrograde transneuronal transfer since it lacks the toxicity of tetanus toxin.     

A mathematical model for the hemolysin of measles virus

A combination of theoretical and empirical approaches have been utilized to develop an accurate and reproducible method for the quantitation of the hemolysin activity associated with measles virus virions. Such a method will be of use in the study of the physiological and biochemical mechanisms involved in viral-induced hemolysis and cell fusion.     

Insurer Views on Reimbursement of Preventive Services in the Dental Setting: Results From a Qualitative Study

Objectives. We explored insurers’ perceptions regarding barriers to reimbursement for oral rapid HIV testing and other preventive screenings during dental care.Methods. We conducted semistructured interviews between April and October 2010 with a targeted sample of 13 dental insurance company executives and consultants, whose firms’ cumulative market share exceeded 50% of US employer-based dental insurance markets. Participants represented viewpoints from a significant share of the dental insurance industry.Results. Some preventive screenings, such as for oral cancer, received widespread insurer support and reimbursement. Others, such as population-based HIV screening, appeared to face many barriers to insurance reimbursement. The principal barriers were minimal employer demand, limited evidence of effectiveness and return on investment specific to dental settings, implementation and organizational constraints, lack of provider training, and perceived lack of patient acceptance.Conclusions. The dental setting is a promising venue for preventive screenings, and addressing barriers to insurance reimbursement for such services is a key challenge for public health policy.Health care providers, the public health community, payers, and health services researchers are increasingly recognizing oral health as a crucial component of the medical home, as well as the potential role of dentists as partners to perform public health screening and to engage patients who may not be receiving regular preventive health services.1–7 Previous research demonstrated high dental care utilization among key populations such as smokers, individuals at elevated risk for HIV, and individuals at risk for diabetes; many at-risk individuals use dental services even when they do not regularly receive primary medical care services.8–11 Furthermore, rapid advances have been made in salivary diagnostics for early disease detection and routine health monitoring. Emergence of the oral rapid HIV and hepatitis C tests has prompted calls for more aggressive screening in the dental setting.12,13 Increased attention is also focusing on the use of clinical periodontal markers and self-reported risk factors to detect undiagnosed diabetes.5,9,14The dental venue has been identified as an untapped resource for the provision of oral rapid HIV screening.8 The Centers for Disease Control and Prevention’s revised 2006 guidelines advocated routine opt-out HIV screening and near-universal screening in diverse settings.15 The oral health component of the Healthy People 2020 initiative includes the aim to “increase the proportion of adults who receive preventive interventions in dental offices [OH-14],” specifically, smoking cessation services [OH-14.1], oral cancer screenings [OH-14.2], and tests and referrals for glycemic control [OH-14.3].16 In a survey of dentists, the majority of respondents endorsed the importance of dental screening for specified systemic conditions, such as cardiovascular disease, hypertension, diabetes, and HIV; almost all respondents highly valued chairside medical screening in dental settings.4Despite this broadening view of dentists’ professional role, actual provision of preventive screenings, including cardiovascular and HIV screenings, is low.17 Low provision of routine tobacco cessation service delivery has also been documented, despite high perceived importance as part of the dentist’s professional responsibility.11 Furthermore, research has shown that dentists are not fully assuming the responsibility of conducting thorough oral cancer screenings, although this screening has been characterized as the single most essential service a dentist can offer and is one of the few dental services that can save a patient’s life when routinely performed.18Dentists’ reluctance to perform medical screenings in their clinical practice is multifactorial; cited barriers to performing HIV oral rapid screening, oral cancer examinations, and tobacco cessation services are lack of training and expertise, time constraints, scope of practice, confidentiality, low perceived disease prevalence, and low index of suspicion.4,19–23Limited insurance reimbursement is another major barrier to broad implementation of comprehensive public health screening in the dental setting.24 From a payer perspective, the feasibility and cost-effectiveness of broad dental chairside screenings remain unclear.8 Insurer perspectives regarding such questions are rarely explored. We investigated attitudes of dental insurers toward expanding routine screening, including oral rapid HIV testing, in the dental setting to promote early diagnosis and treatment of prevalent systemic diseases.     

Simultaneous distal radial fractures and carpal bones injuries in children: a review article

Accurate diagnosis is crucial in effectively managing and treating both the radial and carpal fractures. Injuries to the carpal bones are not usually associated with fractures of the distal radius; however, the presence of a distal radius fracture does not preclude an associated carpal injury. The purpose of this review article is to compile cases of past reported distal radius fractures and simultaneous carpal injuries to restate its low prevalence within the pediatric population while still serving as a collective reference for management and treatment. After an electronic literature search was performed, we identified 18 published articles and 28 cases dealing with combined distal radial and carpal bones injuries in the pediatric population. As the mechanism of injury is similar for both fractures, despite the low incidence, orthopedic surgeons need to rule out carpal injury with a distal forearm fracture. Failure to treat both injuries appropriately may result in an unsatisfactory clinical result.     

In vivo intracardiac optical coherence tomography imaging through percutaneous access: toward image-guided radio-frequency ablation

Complete catheter-tissue contact and permanent tissue destruction are essential for efficient radio-frequency ablation (RFA) during cardiac arrhythmia treatment. Current methods of monitoring lesion formation are indirect and unreliable. The purpose of this study is to evaluate the feasibility of using optical coherence tomography (OCT) catheter to image endocardial wall in actively beating hearts through percutaneous access. We reported the first in vivo intracardiac OCT imaging through percutaneous access with a thin and flexible OCT catheter. This is a critical step toward image-guided RFA in a clinical setting. A cone-scanning forward-viewing OCT catheter was advanced into beating hearts through percutaneous access in four swine. The OCT catheter was steered by an introducer to touch the endocardial wall. We are able to acquire high quality OCT images in beating hearts, observe the polarization-related artifacts induced by the birefringence of myocardium, and readily evaluate catheter-tissue contact. The observations indicate that OCT could be a promising technique for in vivo guidance of RFA.