Super-Resolution Spatial Proximity Detection with Proximity-PAINT.

Visualizing the functional interactions of biomolecules such as proteins and nucleic acids is key to understanding cellular life on the molecular scale. Spatial proximity is often used as a proxy for the direct interaction of biomolecules. However, current techniques to visualize spatial proximity are either limited by spatial resolution, dynamic range, or lack of single-molecule sensitivity. Here, we introduce Proximity-PAINT (pPAINT), a variation of the super-resolution microscopy technique DNA-PAINT. pPAINT uses a split-docking-site configuration to detect spatial proximity with high sensitivity, low false-positive rates, and tunable detection distances. We benchmark and optimize pPAINT using designer DNA nanostructures and demonstrate its cellular applicability by visualizing the spatial proximity of alpha- and beta-tubulin in microtubules using super-resolution detection.

Antibody escape by polyomavirus capsid mutation facilitates neurovirulence.

JCPyV polyomavirus, a member of the human virome, causes progressive multifocal leukoencephalopathy (PML), an oft-fatal demyelinating brain disease in individuals receiving immunomodulatory therapies. Mutations in the major viral capsid protein, VP1, are common in JCPyV from PML patients (JCPyV-PML) but whether they confer neurovirulence or escape from virus-neutralizing antibody (nAb) in vivo is unknown. A mouse polyomavirus (MuPyV) with a sequence-equivalent JCPyV-PML VP1 mutation replicated poorly in the kidney, a major reservoir for JCPyV persistence, but retained the CNS infectivity, cell tropism, and neuropathology of the parental virus. This mutation rendered MuPyV resistant to a monoclonal Ab (mAb), whose specificity overlapped the endogenous anti-VP1 response. Using cryo-EM and a custom sub-particle refinement approach, we resolved an MuPyV:Fab complex map to 3.2 Å resolution. The structure revealed the mechanism of mAb evasion. Our findings demonstrate convergence between nAb evasion and CNS neurovirulence in vivo by a frequent JCPyV-PML VP1 mutation.

Mortality and Morbidity in Office-Based General Anesthesia for Dentistry in Ontario.

Our objective was to estimate the prevalence of mortality and serious morbidity for office-based deep sedation and general anesthesia (DS/GA) for dentistry in Ontario from 1996 to 2015. Data were collected retrospectively in 2 phases. Phase I involved the review of incidents, and phase II involved a survey of DS/GA providers. In phase I, cases involving serious injury or death for dentistry under DS/GA, sourced from the Office of the Chief Coroner of Ontario and from the Royal College of Dental Surgeons of Ontario (RCDSO), were reviewed. Phase II involved a survey of all RCDSO-registered providers of DS/GA in which they were asked to estimate the number of DS/GAs administered in 2015 and the number of years in practice since 1996. Clinician data were pooled to establish an overall number of DS/GAs administered in dental offices in Ontario from 1996 to 2015. Prevalence was calculated using phase I (numerator) and phase II (denominator) findings. The estimated prevalence of mortality in the 20-year period from 1996 to 2015 was 3 deaths in 3,742,068 cases, with an adjusted mortality rate of 0.8 deaths per 1 million cases. The estimated prevalence of serious morbidity was 1 injury in 3,742,068 cases, which adjusts to a serious morbidity rate of 0.25 per 1 million cases. The mortality rate found in this study was slightly lower than those published by earlier studies conducted in Ontario. The risk of serious morbidity was found to be low and similar to other studies investigating morbidity in office-based dental anesthesia.

Moral foundations are not moral propositions.

Joshua May responds to skepticism about moral knowledge via appeal to empirical work on moral foundations. I demonstrate that the moral foundations literature is not able to do the work May needs. It demonstrates shared moral cognition, not shared moral judgment, and therefore, May's attempt to defeat general skepticism fails.

Quantifying absolute addressability in DNA origami with molecular resolution.

Self-assembled DNA nanostructures feature an unprecedented addressability with sub-nanometer precision and accuracy. This addressability relies on the ability to attach functional entities to single DNA strands in these structures. The efficiency of this attachment depends on two factors: incorporation of the strand of interest and accessibility of this strand for downstream modification. Here we use DNA-PAINT super-resolution microscopy to quantify both incorporation and accessibility of all individual strands in DNA origami with molecular resolution. We find that strand incorporation strongly correlates with the position in the structure, ranging from a minimum of 48% on the edges to a maximum of 95% in the center. Our method offers a direct feedback for the rational refinement of the design and assembly process of DNA nanostructures and provides a long sought-after quantitative explanation for efficiencies of DNA-based nanomachines.

Ontario Dentists' Estimation of Patient Interest in Anesthesia.

Objective: To investigate Ontario dentists' perceptions of patient interest in sedation and general anesthesia (GA) during treatment and patient fear and avoidance of dental treatment. Methods: Using the Royal College of Dental Surgeons of Ontario roster, we randomly selected 3001 practising Ontario dentists, from among those who listed an email address, to complete a 16-question survey by mail or online. Demographic information (e.g., gender, size and type of primary practice, and years of experience) was collected as well as dentist reports of patient interest in sedation/GA and level of fear regarding treatment. Analysis included sample t-tests to compare Ontario dentist responses with patient responses to a 2002 national survey. Results: 1076 dentists participated (37.9% response rate), comprised of 69.7% males, 84.4% general practitioners, 0.5­42 years of practice (mean 20.6 years), and 40.6% from cities with a population larger than 500,000. Dentists underestimated patients' interest in sedation/GA, with dentists and patients reporting patients "Not interested" as 66.8% and 43.9%, respectively, and "Interested depending on cost," 19.8% v. 42.3%. Dentists also underestimated patient interest in sedation/GA for specific dental procedures including scaling, fillings/crowns, root canal therapy and periodontal surgery (p < 0.01). Dentists overestimated patient fear levels ("Somewhat afraid," 19.9% v. 9.8%; "Very afraid," 10.6% v. 2.0%; "Terrified," 6.0% v. 3.5%) and the proportion of patients avoiding dental care (13.3% v. 7.6%). Conclusion: Dentists underestimate patients' preference for sedation/GA and overestimate their fear and avoidance of dental care. The significant disparities between the views of dentists and patients may affect the availability and provision of sedation and general anesthesia in Ontario dental practices.

Pharmacotherapy in Temporomandibular Disorders: A Review.

Temporomandibular disorder (TMD) is a collective term that includes disorders of the temporomandibular joint (TMJ) and of the masticatory muscles and their associated structures. TMDs are characterized by pain, joint sounds and restricted mandibular movement, and drugs are widely used in the management of that pain. Pharmacological agents commonly used for the treatment of TMDs include non-steroidal anti-inflammatory drugs (NSAIDs), opioids, corticosteroids, muscle relaxants, antidepressants, anticonvulsants and benzodiazepines. In this paper, we discuss these agents and the potential adverse drug reactions and interactions associated with their use. Temporomandibular disorder (TMD) is a collective term used for a number of clinical problems that involve the masticatory muscle complex, the temporomandibular joint (TMJ) and associated structures. TMD is one of the most common disorders in the maxillofacial region. Signs and symptoms of TMD may include pain, impaired jaw function, malocclusion, deviation from the midline on opening or closing the jaw, limited range of motion, joint noises and locking.1 Among other signs and symptoms, headaches and sleep disturbances can appear concomitantly.2 This disorder is most prevalent in people aged 20-40 years.3 Approximately 33% of the population have at least 1 TMD symptom, and 3.6-7.0% of the population have TMD with sufficient severity to seek treatment.3 There is some evidence to suggest that anxiety, stress and other emotional disturbances exacerbate TMD.4 As many as 75% of patients with TMD have a significant psychological abnormality.5 Most TMD symptoms resolve over time, but, for a significant number of patients, this may take a year or more.3 Treatment is directed toward reducing pain and improving function. Many non-invasive therapies, such as self-care, physical therapy and appliance therapy, are commonly used for the treatment of TMD.3 Pharmacological intervention has been used for many years, and the most effective pharmacological agents for the treatment of TMD include analgesics, non-steroidal anti-inflammatory drugs (NSAIDs), opioids, corticosteroids, anxiolytics, muscle relaxants, antidepressants, anticonvulsants and benzodiazepines. However, we found only 1 relevant Cochrane study, which included 11 randomized controlled trials of pharmacotherapy for TMD.6 In this article, we review the pharmacology and research supporting the use of a host of pharmacologic agents that have been prescribed for patients who have TMD. The decision to select any of these agents depends on a full understanding of the drug's risks and benefits.

Postoperative Pain in Children After Dentistry Under General Anesthesia.

The objective of this study was to determine the prevalence, severity, and duration of postoperative pain in children undergoing general anesthesia for dentistry. This prospective cross-sectional study included 33 American Society of Anesthesiology (ASA) Class I and II children 4-6 years old requiring multiple dental procedures, including at least 1 extraction, and/or pulpectomy, and/or pulpotomy of the primary dentition. Exclusion criteria were children who were developmentally delayed, cognitively impaired, born prematurely, taking psychotropic medications, or recorded baseline pain or analgesic use. The primary outcome of pain was measured by parents using the validated Faces Pain Scale-Revised (FPS-R) and Parents' Postoperative Pain Measure (PPPM) during the first 72 hours at home. The results showed that moderate-to-severe postoperative pain, defined as FPS-R ≥ 6, was reported in 48.5% of children. The prevalence of moderate-to-severe pain was 29.0% by FPS-R and 40.0% by PPPM at 2 hours after discharge. Pain subsided over 3 days. Postoperative pain scores increased significantly from baseline (P < .001, Wilcoxon matched pairs signed rank test). Moderately good correlation between the 2 pain measures existed 2 and 12 hours from discharge (Spearman rhos correlation coefficients of 0.604 and 0.603, P < .005). In conclusion, children do experience moderate-to-severe pain postoperatively. Although parents successfully used pain scales, they infrequently administered analgesics.

PHARMACOTHERAPY FOR THE ELDERLY DENTAL PATIENT.

Current demographic data clearly show that the North American population is aging, and projections suggest that the percentage of older people will increase. The elderly often suffer from multiple chronic conditions that affect their quality of life, use of health services, morbidity and mortality. Also, in those of advanced age, the pharmacokinetics and pharmacodynamics of many drugs are altered. Polypharmacy increases the incidence of adverse drug reactions and drug interactions in this population. Thus, the dentist must be continually aware of the pharmacologic status of each patient and consider the likelihood of interactions between drugs prescribed by the dentist, drugs prescribed by the physician and drugs that are self-administered, including over-the-counter medications and natural supplements. In this article, we discuss pharmacokinetic and pharmacodynamic changes in the elderly patient, polypharmacy and the changes in prescribing for our dental patients. Specific emphasis is placed on the drugs commonly prescribed by dentists: local anesthetics, analgesics and antibiotics.

App Store for EHRs and Patients Both.

The Substitutable Medical Applications, Reusable Technologies (SMART) Platforms project ( www.smartplatforms.org ) seeks to develop an iPhone-like health information technology platform with substitutable apps constructed around core services. It is funded by a grant from the Office of the National Coordinator of Health Information Technology's Strategic Health IT Advanced Research Projects (SHARP) Program. SMART technologies enable existing electronic health records and HIT platforms to run substitutable apps. Substitutability is the capability inherent in a system of replacing one application with another of similar functionality. We created a patient-facing SMART instance using the open source Indivo personally controlled health record (PCHR). The SMART "read-only" API has been deployed on multiple systems, including the Cerner installation at Boston Children's Hospital and the World Vista EHR. We sought to SMART-enable Indivo, the open source reference PCHR upon which HealthVault and other PCHRs were modeled. PCHRs provide patients with a secure repository of their health information that can be exposed to apps across a programming interface. We updated the open source Indivo PCHR to support the SMART API, enabling Indivo to act as a patient-facing apps platform, running the same or similar versions of apps that face clinicians.

The effect of smoking on the bioavailability of metronidazole in plasma and saliva.

BACKGROUND: Cigarette smoking is considered to be a major risk factor for periodontal disease, and the antimicrobial agent metronidazole is commonly used for treatment of periodontitis. The authors evaluated the effect of cigarette smoking on the bioavailability of metronidazole in plasma and saliva. METHODS: Thirteen smokers and 13 nonsmokers received a single oral dose of 750 milligrams of metronidazole. Study personnel collected blood and saliva samples at baseline and at 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24 and 48 hours after metronidazole administration. The authors quantified plasmatic and salivary metronidazole concentrations by means of high-performance liquid chromatography, and they determined the pharmacokinetic parameters and analyzed them statistically by using the Mann-Whitney test and nonpaired t test (α = 5 percent). RESULTS: The authors detected a significant reduction in plasmatic metronidazole concentrations in smokers at 1 hour, 1.5 hours and 2 hours compared with nonsmokers (P < .05). They also found a significant reduction in the maximum concentration in plasma in smokers as compared with that of nonsmokers (P < .05). The authors observed no statistically significant differences in the salivary concentration or pharmacokinetics between the two groups, however (P > .05). CONCLUSION: Cigarette smoking interfered with the bioavailability of metronidazole in plasma but not in saliva. Practice Implications. The clinical significance of these findings needs to be investigated further to verify the effectiveness of metronidazole in smokers.

Recognition and management of complications during moderate and deep sedation. Part 2: cardiovascular considerations.

The risk for cardiovascular complications while providing any level of sedation or general anesthesia is greatest when caring for patients already medically compromised. It is reassuring that significant untoward events can generally be prevented by careful preoperative assessment, along with attentive intraoperative monitoring and support. Nevertheless, providers must be prepared to manage untoward events should they arise. This continuing education article will review cardiovascular complications and address their appropriate management.

Alternative mandibular nerve block techniques: a review of the Gow-Gates and Akinosi-Vazirani closed-mouth mandibular nerve block techniques.

BACKGROUND: and Overview. The limited success rate of the standard inferior alveolar nerve block (IANB) has led to the development of alternative approaches for providing mandibular anesthesia. Two techniques, the Gow-Gates mandibular nerve block and the Akinosi-Vazirani closed-mouth mandibular nerve block, are reliable alternatives to the traditional IANB. The Gow-Gates technique requires the patient's mouth to be open wide, and the dentist aims to administer local anesthetic just anterior to the neck of the condyle in proximity to the mandibular branch of the trigeminal nerve after its exit from the foramen ovale. The Akinosi-Vazirani technique requires the patient's mouth to be closed, and the dentist aims to fill the pterygomandibular space with local anesthetic. CONCLUSION: Both techniques are indicated for any type of dentistry performed in the mandibular arch, but they are particularly advantageous when the patient has a history of standard IANB failure owing to anatomical variability or accessory innervation. CLINICAL IMPLICATIONS: Having the skill to perform these alternative anesthetic techniques increases dentists' ability to provide successful local anesthesia consistently for all procedures in mandibular teeth.

Recognition and management of complications during moderate and deep sedation part 1: respiratory considerations.

The risk for complications while providing any level of sedation or general anesthesia is greatest when caring for patients having significant medical compromise. It is reassuring that significant untoward events can generally be prevented by careful preoperative assessment, along with attentive intraoperative monitoring and support. Nevertheless, we must be prepared to manage untoward events should they arise. This continuing education article will review respiratory considerations and will be followed by a subsequent article addressing cardiovascular considerations.

Paresthesias in dentistry.

Alterations to normal oral sensory function can occur following restorative and surgical dental procedures. Paresthesia is defined as an abnormal sensation, such as burning, pricking, tickling, or tingling. Paresthesias are one of the more general groupings of nerve disorders known as neuropathies. This article reviews the extent of this oral complication as it relates to dental and surgical procedures, with specific emphasis on paresthesias associated with local anesthesia administration. This review establishes a working definition for paresthesia as it relates to surgical trauma and local anesthesia administration, describes the potential causes for paresthesia in dentistry, assesses the incidence of paresthesias associated with surgery and local anesthesia administration, addresses the strengths and weaknesses in research findings, and presents recommendations for the use of local anesthetics in clinical practice.

Occurrence of paresthesia after dental local anesthetic administration in the United States.

BACKGROUND: Several studies have suggested that the likelihood of paresthesia may depend on the local anesthetic used. The purpose of this study was to determine if the type of local anesthetic administered had any effect on reports of paresthesia in dentistry in the United States. METHODS: The authors obtained reports of paresthesia involving dental local anesthetics during the period from November 1997 through August 2008 from the U.S. Food and Drug Administration Adverse Event Reporting System. They used chi(2) analysis to compare expected frequencies, on the basis of U.S. local anesthetic sales data, with observed reports of oral paresthesia. RESULTS: During the study period, 248 cases of paresthesia occurring after dental procedures were reported. Most cases (94.5 percent) involved mandibular nerve block. The lingual nerve was affected in 89.0 percent of cases. Reports involving 4 percent prilocaine and 4 percent articaine were 7.3 and 3.6 times, respectively, greater than expected (chi(2), P < .0001) on the basis of local anesthetic use by U.S. dentists. CONCLUSIONS: These data suggest that paresthesia occurs more commonly after use of 4 percent local anesthetic formulations. These findings are consistent with those reported in a number of studies from other countries. CLINICAL IMPLICATIONS: Until further research indicates otherwise, dentists should consider these results when assessing the risks and benefits of using 4 percent local anesthetics for mandibular block anesthesia.

Preparing dental office staff members for emergencies: developing a basic action plan.

BACKGROUND AND OVERVIEW: A medical emergency can occur in any dental office, and managing it successfully requires preparation. The dentist should develop a basic action plan that is understood by all staff members. The goal is to manage the patient's care until he or she recovers fully or until help arrives. The most important aspect of almost all medical emergencies in dentistry is to prevent or correct insufficient oxygenation of the brain or heart. The dentist or a staff member needs to position (P) the patient appropriately. He or she then needs to assess and, if needed, manage the airway (A), breathing (B) and circulation (C). The dentist and staff members then can consider 'D,' which stands for definitive treatment, differential diagnosis, drugs or defibrillation. A team approach should be used, with each staff member trained in basic life support and understanding the role expected of him or her ahead of time. Clear and effective communication is essential during any emergency. CONCLUSIONS: All staff members should understand the basic action plan so that they can put it into effect should any emergency arise in the dental office. CLINICAL IMPLICATIONS: Preparing staff members is integral to the successful management of a medical emergency in the dental office.

Survey of local anesthetic use by Ontario dentists.

OBJECTIVE: Local anesthetics are believed to be the most frequently used drugs in clinical dentistry, and although they are generally regarded as safe, some adverse reactions can be expected and do occur. The purpose of this study was to obtain, by means of a mail survey, information on the types and amounts of local anesthetics used by Ontario dentists during 2007. MATERIALS AND METHODS: A survey requesting data on the annual use of injectable local anesthetics was mailed to all 8,058 dentists licensed by the Royal College of Dental Surgeons of Ontario in 2007. RESULTS: The effective response rate to the single mailing was 17.3% (1,395 respondents). By extrapolation, the estimated use of local anesthetics by all Ontario dentists during 2007 was determined to be about 13 million cartridges, which represents an average of 1,613 cartridges per dentist per year. Lidocaine with epinephrine 1:100,000 was the most commonly used formulation with 37.31% of total anesthetic use, followed by articaine with 1:200,000 epinephrine (27.04%) and articaine with 1:100,000 epinephrine (17.16%). Overall, local anesthetics combined with a vasoconstrictor accounted for more than 90% of total anesthetic use. A minority of survey respondents (15.68%) indicated that their pattern of anesthetic use had changed significantly in the past few years. Patterns of use were similar for early and late survey respondents. These data provide a current account of the use of local anesthetics by Ontario dentists.

Retrospective review of voluntary reports of nonsurgical paresthesia in dentistry.

OBJECTIVE: Paresthesia is an adverse event that may be associated with the administration of local anesthetics in dentistry. The purpose of this retrospective study was to analyze cases of paresthesia associated with local anesthetic injection that were voluntarily reported to Ontario"s Professional Liability Program (PLP) from 1999 to 2008 inclusive, to see if the findings were consistent with those from 1973 to 1998 from this same source. MATERIALS AND METHODS: All cases of nonsurgical paresthesia reported from 1999 to 2008 were reviewed; cases involving surgical procedures were excluded. Variables examined included patient age and gender, type and volume of local anesthetic, anatomic site of nerve injury, affected side and pain on injection or any other symptoms. RESULTS: During the study period, 182 PLP reports of paresthesia following nonsurgical procedures were made; all but 2 were associated with mandibular block injection. There was no significant gender predilection, but the lingual nerve was affected more than twice as frequently as the inferior alveolar nerve. During 2006-2008 alone, 64 cases of nonsurgical paresthesia were reported to PLP, a reported incidence of 1 in 609,000 injections. For the 2 local anesthetic drugs available in dental cartridges as 4% solutions, i.e., articaine and prilocaine, the frequencies of reporting of paresthesia were significantly greater than expected (chi2, exact binomial distribution; p < 0.01) based on their level of use by Ontario dentists. These data suggest that local anesthetic neurotoxicity may be at least partly involved in the development of postinjection paresthesia.

Effect of time on clinical efficacy of topical anesthesia.

The objective of this study was to determine the effect of time on the clinical efficacy of topical anesthetic in reducing pain from needle insertion alone as well as injection of anesthetic. This was a randomized, double-blind, placebo-controlled, split-mouth, clinical trial which enrolled 90 subjects, equally divided into 3 groups based upon time (2, 5, or 10 minutes) of topical anesthetic (5% lidocaine) application. Each group was further subdivided into 2: needle insertion only in the palate or needle insertion with deposition of anesthetic (0.5 mL 3% mepivacaine plain). Each subject received drug on one side and placebo on the other. Subjects recorded pain on a 100-mm visual analog scale (VAS). The results showed that for needle insertion only, 5% lidocaine reduced pain as determined by a significant difference in mean VAS after 2 minutes (20.1 mm, P < .002), 5 minutes (15.7 mm, P < .022), and 10 minutes (13.7 mm, P < .04), as analyzed by paired t tests. For needle insertion plus injection of local anesthetic, a significant difference in mean VAS was noted only after 10 minutes (14.9 mm, P < .031), yet pain scores for both topical anesthetic and placebo were elevated at this time point resulting in no reduction in actual pain. Time of application did not result in a significant difference in effect for either needle insertion only or needle insertion plus injection of local anesthetic, as analyzed by 1-way analysis of variance (ANOVA). In conclusion, topical anesthetic reduces pain of needle insertion if left on palatal mucosa for 2, 5, or 10 minutes, but has no clinical pain relief for anesthetic injection.