Effects of universal masking on Massachusetts healthcare workers' COVID-19 incidence.

BACKGROUND: Healthcare workers (HCWs) and other essential workers are at risk of occupational infection during the COVID-19 pandemic. Several infection control strategies have been implemented. Evidence shows that universal masking can mitigate COVID-19 infection, though existing research is limited by secular trend bias. AIMS: To investigate the effect of hospital universal masking on COVID-19 incidence among HCWs compared to the general population. METHODS: We compared the 7-day average incidence rates between a Massachusetts (USA) healthcare system and Massachusetts residents statewide. The study period was from 17 March (the date of first incident case in the healthcare system) to 6 May (the date Massachusetts implemented public masking). The healthcare system implemented universal masking on 26 March, we allotted a 5-day lag for effect onset and peak COVID-19 incidence in Massachusetts was 20 April. Thus, we categorized 17-31 March as the pre-intervention phase, 1-20 April the intervention phase and 21 April to 6 May the epidemic decline phase. Temporal incidence trends (i.e. 7-day average slopes) were compared using standardized coefficients from linear regression models. RESULTS: The standardized coefficients were similar between the healthcare system and the state in both the pre-intervention and epidemic decline phases. During the intervention phase, the healthcare system's epidemic slope became negative (standardized ß: -0.68, 95% CI: -1.06 to -0.31), while Massachusetts' slope remained positive (standardized ß: 0.99, 95% CI: 0.94 to 1.05). CONCLUSIONS: Universal masking was associated with a decreasing COVID-19 incidence trend among HCWs, while the infection rate continued to rise in the surrounding community.

Can the pattern of vertebral marrow oedema differentiate intervertebral disc infection from degenerative changes?

AIM: To evaluate whether various patterns of bone marrow oedema could be used to discriminate between infection and degenerative change. MATERIALS AND METHODS: Seventy patients with imaging features suspicious for discitis and available clinical follow-up were blindly reviewed for vertebral marrow oedema on sagittal short-tau inversion recovery (STIR) images according to the following patterns: I, vertebra oedema is adjacent to the intervertebral space and sharply-marginated; II, vertebral oedema is adjacent to the intervertebral space but not sharply marginated from normal marrow or involves the entire vertebral body; and III, vertebral oedema is distant from the endplate with intervening hypointense marrow signal. RESULTS: Of 45 patients with a clinical diagnosis of discitis, pattern II was the most common oedema pattern (64%). Approximately 20% and 9% of discitis patients showed patterns I and III, respectively. In patients with degenerative changes, 44% patients showed pattern I, 32% showed pattern II, and 24% showed pattern III. Pattern II had a sensitivity, specificity, and positive predictive value of 0.64, 0.68, and 0.78 for diagnosing spine infection, respectively. CONCLUSIONS: Although bone marrow oedema in infective discitis most often extends from the disc space and has indistinct margins, the oedema may also have sharp margins or be remote from the involved intervertebral space. Bone marrow oedema patterns of infective discitis overlap with those of degenerative disease and are not sufficiently reliable to exclude infection in cases with magnetic resonance imaging findings suggestive of discitis.

3D T2 MR Imaging-Based Measurements of the Posterior Cervical Thecal Sac in Flexion and Extension for Cervical Puncture.

BACKGROUND AND PURPOSE: The current standard technique for cervical puncture involves prone positioning with neck extension. The purpose of this study was to compare measurements of the posterior cervical thecal sac during neck flexion and extension in supine and prone positions by using high-resolution MR imaging to help determine the optimal positioning for cervical puncture. MATERIALS AND METHODS: High-resolution T2-weighted MR imaging was performed of the cervical spine in 10 adult volunteers 18 years of age and older. Exclusion criteria included the following: a history of cervical spine injury/surgery, neck pain, and degenerative spondylosis. Images of sagittal 3D sampling perfection with application-optimized contrasts by using different flip angle evolutions were obtained in the following neck positions: supine extension, supine flexion, prone extension, and prone flexion. The degree of neck flexion and extension and the distance from the posterior margin of the spinal cord to the posterior aspect of the C1-C2 thecal sac were measured in each position. RESULTS: The mean anteroposterior size of the posterior C1-C2 thecal sac was as follows: 4.76 mm for supine extension, 3.63 mm for supine flexion, 5.00 mm for prone extension, and 4.00 mm for prone flexion. Neck extension yielded a larger CSF space than flexion, independent of supine/prone positioning. There was no correlation with neck angle and thecal sac size. CONCLUSIONS: The posterior C1-C2 thecal sac is larger with neck extension than flexion, independent of prone or supine positioning. Given that this space is the target for cervical puncture, findings suggest that extension is the ideal position for performing the procedure, and the decision for prone-versus-supine positioning can be made on the basis of operator comfort and patient preference/ability.

Enhanced sensitivity detection of protein immobilization by fluorescent interference on oxidized silicon.

We present a silicon chip-based approach for the enhanced sensitivity detection of surface-immobilized fluorescent molecules. Green fluorescent protein (GFP) is bound to the silicon substrate by a disuccinimidyl terephtalate-aminosilane immobilization procedure. The immobilized organic layers are characterized by surface analysis techniques, like ellipsometry, atomic force microscopy (AFM) and X-ray induced photoelectron spectroscopy. We obtain a 20-fold enhancement of the fluorescent signal, using constructive interference effects in a fused silica dielectric layer, deposited before immobilization onto the silicon. Our method opens perspectives to increase by an order of magnitude the fluorescent response of surface immobilized DNA- or protein-based layers for a variety of biosensor applications.

La prevalence des dysfonctions craniomandibulaires chez les patients ages

Ce travail rapporte les resultats d'une enquete epidemiologique transversale et analytique sur la prevalence des dysfonctions craniomandibulaires. Notre etude a ete realisee au Centre de Consultations et Traitements Dentaires de Casablanca chez 100 patients ages de 50 ans et plus. Pour evaluer les symptomes des dysfonctions de l'appareil manducateur (DAM); nous avons utilise l'indice d'anamnese d'Helkimo ; 72de notre echantillon rapportent des symptomes de DAM; le bruit articulaire est le symptome le plus rapporte (64). 67de notre population cible decrivent des habitudes nocives : 28ont de mauvaises postures; 18serrent leurs machoires et 16grincent des dents. L'analyse statistique a revele une association entre les habitudes nocives et l'apparition des DAM. 32de ces individus ont une perte de calage posterieur; 23sont porteurs de PAT; et 10sont des edentes complets non appareilles; nous n'avons pas trouve d'association entre l'etat dentaire et l'apparition des DCM

Modular microsystem for epithelial cell culture and electrical characterisation.

We have realised a microsystem for the culture and electrical characterisation of epithelial cell layers for cell-based diagnostic applications. The main goal of this work is to achieve both cell culture and impedimetric and potentiometric characterisation on a single device. The miniaturised cell culture system enables the uses of scarce epithelial cells, as obtained from transgenic mice or from human biopsies. The device is completely modular and offers high flexibility: a polycarbonate membrane used as cell substrate is glued in between two moulded Polydimethylsiloxane (PDMS) layers to form a sandwich, which is placed between two stacks, containing the microfluidic channels and integrated measurement electrodes. The polycarbonate membrane sandwich can be removed, replaced or analysed at any time. We have characterised the impedimetric properties of our microsystem, demonstrated epithelial cell layer growth within it, and have done the initial electrical characterisation of epithelial cell layers.

Emergency medical services providers and weapons in the prehospital setting.

OBJECTIVES: To investigate emergency medical services (EMS) providers' experience with weapons encountered while working, and evaluate the training they have received regarding searching for and confiscating weapons in the field. METHODS: This was a descriptive, cross-sectional survey anonymously completed by a convenience sample of EMS providers in the metropolitan Boston and Los Angeles (LA) areas. RESULTS: Of 2,672 surveys distributed, 2,224 (83%) were returned. Forty-two percent of the respondents (39% of Boston and 46% of LA) reported searching patients for weapons, and 62% (51% of Boston and 76% of LA) reported finding weapons. The LA respondents were more likely than the Boston respondents to have found a firearm. Twenty-seven percent of the respondents reported they had found more than five weapons in their careers. One thousand seven hundred seventy-two (80%) providers replied that they would report discovered weapons, most frequently to law enforcement personnel. Providers with higher EMS education and ones who received weapons-related training were more likely to search for, find, and report weapons. Four hundred fifty-one (20%) respondents reported receiving formal weapons-related training, 291 (13%) considered their initial EMS training on weapons-related topics to be adequate, and 292 (13%) considered their continuing education in these areas adequate. CONCLUSIONS: These data suggest that weapons encountered in the field are a widespread problem for EMS providers. Although many EMS providers search for and find weapons on their patients, most of them feel they have been inadequately trained in this area. Prospective studies are needed to document the actual incidence of weapon encounters in the prehospital setting. Multidisciplinary discussions are needed to address the above issues.

Prehospital thrombolysis: an idea whose time has come.

Aggressive reperfusion therapy for myocardial infarction (MI) characterized by acute ST-segment elevation leads to improved patient outcome. Furthermore, use of thrombolytic therapy is highly time-dependent: reperfusion therapy is beneficial within 12 h, but the earlier it is administered, the more beneficial it is. Thus, the focus of both prehospital and emergency department management of patients with acute MI is on rapid identification and treatment. There are many components to the time delays between the onset of symptoms of acute MI and the achievement of reperfusion in the occluded infarct-related artery. Time delays occur with both the patient and the prehospital emergency medical system, although patient delays are more significant. This article focuses on the prehospital management of acute MI, including (1) the rationale for rapid reperfusion in patients with acute MI, (2) the factors related to time delays in patient presentation to the hospital, and (3) strategies for reducing time delays, both patient- and medical system-based.

Field experience with prehospital advance directives.

STUDY OBJECTIVE: Some states have enacted legislation authorizing EMS providers to adhere to prehospital advance directives (ADs) in the terminally ill. This study was conducted to assess EMS providers' knowledge of and experience with prehospital ADs. METHODS: An anonymous survey was conducted of 142 EMS providers employed by a local, private ambulance service in the northeastern United States. The survey was administered during a 2-month period from January to March 1995. RESULTS: Of 142 participating providers, 106 (74.6%) completed questionnaires. Respondents included EMTs (61. 3%), paramedics (33.9%), and chair van operators (4.8%). The majority (58.6%) had at least 5 years of field experience. Almost all respondents (93.4%) were familiar with ADs, usually do-not-resuscitate orders. Most providers (78.3%) consider ADs before implementing extraordinary life support measures in terminally ill patients. Few (28.0%) have implemented prehospital ADs without medical control. The most commonly reported objections to withholding life support measures were fear of legal consequences, personal difficulty withholding care they are trained to provide, and ambiguity in the ADs received. Nearly all respondents (96.7%) support enactment of prehospital AD statutes. CONCLUSION: Most prehospital care providers recognize the need to withhold resuscitative care in terminally ill patients who have prepared ADs. However, a sizable minority fail to consider prehospital ADs as a routine part of their practice. The majority of our respondents support enactment of prehospital AD statutes to minimize confusion and provide legal authorization to limit resuscitation.

Chemically etched fiber tips for near-field optical microscopy: a process for smoother tips.

An improved method for producing fiber tips for scanning near-field optical microscopy is presented. The improvement consists of chemically etching quartz optical fibers through their acrylate jacket. This new method is compared with the previous one in which bare fibers were etched. With the new process the meniscus formed by the acid along the fiber does not move during etching, leading to a much smoother surface of the tip cone. Subsequent metallization is thus improved, resulting in better coverage of the tip with an aluminum opaque layer. Our results show that leakage can be avoided along the cone, and light transmission through the tip is spatially limited to an optical aperture of a 100-nm dimension.

An occult cause of persistent nausea and vomiting.

We report a patient with multiple negative evaluations during emergency department visits and inpatient admissions for unexplained, intermittent nausea, vomiting, and abdominal pain. The etiology of her symptoms was not revealed until her 13th hospital visit, when head magnetic resonance imaging suggested active neurocysticercosis. Central etiologies should be considered for intractable nausea and vomiting in neurologically intact patients even if head computed-assisted tomography scan is negative.

End-tidal CO2 measurement in the detection of esophageal intubation during cardiac arrest.

Measurement of end-tidal carbon dioxide (ETCO2) has been used to detect accidental esophageal tube placement in noncardiac arrest situations. The purpose of our study was to determine whether ETCO2 measurement could distinguish tracheal from esophageal tube placement during closed-chest massage (CCM). Twelve large dogs were anesthetized, and endotracheal tubes were placed in both the trachea and the esophagus. Placement was verified by fiberoptic endoscopy. Ventricular fibrillation was induced by a 60-Hz discharge through a right ventricular pacemaker. After four minutes of cardiac arrest, CCM was initiated and continued for 20 minutes. The dogs were divided into two groups: Group A was ventilated through the tracheal tube, and group B was ventilated through the esophageal tube. Unused tubes were removed. ETCO2 was recorded continuously beginning two minutes before arrest until the end of the experiment. There were no significant between-group differences in mean arterial pressure, weight, blood loss, IV fluid volume administered, or prearrest arterial blood gases. ETCO2 differed significantly between the two groups throughout CCM (P = .001). In group A, ETCO2 ranged from 13 to 34 mm Hg (median, 20 mm Hg). In group B, ETCO2 ranged from 2 to 11 mm Hg (median, 3 mm Hg). In this experimental model, measurement of ETCO2 reliably distinguished esophageal from tracheal intubation during cardiac arrest and CCM. If confirmed in human beings, this may prove to be a quick, reliable method of detecting esophageal intubation during cardiac arrest.