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Introduction Hemorrhage is the second leading cause of death among urban trauma patients, and the provision of prehospital blood-based resuscitation can be lifesaving. We developed an efficient system to support blood-based resuscitation by an urban advanced life support ambulance system. Methods We worked with our state health department for permission for fire department paramedics to initiate blood transfusion and built protocols for field whole blood resuscitation. Our regional trauma center transfusion service provided 2 units of O positive, low-titer, leukoreduced whole blood in an internally monitored and sealed ice box weighing 10 pounds to the fire department paramedic supervisor. When notified, the supervisor transported the blood to the sites of anticipated need. Total blood use and wastage were recorded. Results Following two public hearings, we obtained state-wide approval for the initiation of emergency uncrossmatched blood transfusion by paramedics. Over a 1-year period beginning August 27, 2019, 160 units of whole blood were made available for use, and 51 units were transfused to 39 patients, 30 of whom were trauma patients. Other recipients include patients in shock from massive gastrointestinal, peripartum, or other suspected bleeding. Unused units were returned to the providing transfusion service after 1 week and used for hospital patient care without loss. The estimated cost of providing blood per mission was $0.28 and per patient transfused was $1138. Conclusions With appropriate attention to detail, it is possible to provide whole blood to an urban paramedical ambulance system with efficient blood component usage, minimal blood wastage, and low cost.

Recent innovations in computational structural biology have opened an opportunity to revise our current understanding of the structure and function of clinically important proteins. This study centres on human Oca2 which is located on mature melanosomal membranes. Mutations of Oca2 can result in a form of oculocutanous albinism which is the most prevalent and visually identifiable form of albinism. Sequence analysis predicts Oca2 to be a member of the SLC13 transporter family but it has not been classified into any existing SLC families. The modelling of Oca2 with AlphaFold2 and other advanced methods shows that, like SLC13 members, it consists of a scaffold and transport domain and displays a pseudo inverted repeat topology that includes re-entrant loops. This finding contradicts the prevailing consensus view of its topology. In addition to the scaffold and transport domains the presence of a cryptic GOLD domain is revealed that is likely responsible for its trafficking from the endoplasmic reticulum to the Golgi prior to localisation at the melanosomes and possesses known glycosylation sites. Analysis of the putative ligand binding site of the model shows the presence of highly conserved key asparagine residues that suggest Oca2 may be a Na+/dicarboxylate symporter. Known critical pathogenic mutations map to structural features present in the repeat regions that form the transport domain. Exploiting the AlphaFold2 multimeric modelling protocol in combination with conventional homology modelling allowed the building of a plausible homodimer in both an inward- and outward-facing conformation supporting an elevator-type transport mechanism.

BACKGROUND There is substantial investment in layperson and first responder training involving tourniquet use for hemorrhage control. Little is known however about prehospital tourniquet application, field conversion, or outcomes in the civilian setting. We describe the experience of a metropolitan region with prehospital tourniquet application. METHODS We conducted a retrospective cohort study characterizing prehospital tourniquet use treated by emergency medical services (EMS) in King County, Washington, from January 2018 to June 2019. Emergency medical services and hospital records were abstracted for demographics, injury mechanism, tourniquet details, clinical care, and outcomes. We evaluated the incidence of tourniquet application, who applied the device (EMS, law enforcement, or layperson), and subsequent course. RESULTS A total of 168 patients received tourniquet application, an incidence of 5.1 per 100,000 person-years and 3.48 per 1,000 EMS responses for trauma. Tourniquets were applied for penetrating trauma (64%), blunt trauma (30%), and bleeding ateriovenous fistulas (7%). A subset was critically ill: 13% had systolic blood pressures of

Background Sepsis risk stratification tools typically predict mortality, although stays in the intensive care unit (ICU) of 24 hours or longer may be more clinically relevant for emergency department disposition. Objective To explore predictors of ICU stay of 24 hours or longer among infected, hypotensive emergency department patients. Methods A secondary analysis of 2 prospective, observational studies of adult patients with severe sepsis or an infection with a systolic blood pressure less than 90 mm Hg in 3 urban, academic emergency departments was performed. Patients with hypotension and infection were included. Patients with emergency department intubation, vasopressor administration, and/or death were excluded. The primary outcome was ICU stay of 24 hours or longer or death in less than 24 hours. Multivariable logistic regression was used to predict ICU stay of 24 hours or longer. Results Of 233 patients, 108 (46.4%) had ICU stays of 24 hours or longer. History of heart failure (odds ratio, 3.6; 95% CI, 1.5-8.3), bicarbonate level less than 20 mEq/L (odds ratio, 2.0; 95% CI, 1.1-3.8), respiratory rate greater than 20/min (odds ratio, 2.0; 95% CI, 1.1-3.7), and creatinine level greater than 2.0 mg/dL (odds ratio, 3.6; 95% CI, 1.9-6.7) were independent predictors of ICU stay of 24 hours or longer (area under curve, 0.74). The presence of 1 of these factors predicted ICU stay of 24 hours or longer (area under curve, 0.74) with 82.4% sensitivity and 49.6% specificity. Conclusions These exploratory results show that heart failure, bicarbonate level of less than 20 mEq/L, tachypnea, or creatinine level greater than 2.0 mg/dL increases the likelihood of an ICU stay of 24 hours or longer among infected, hypotensive emergency department patients.

Objectives: Traumatic hand injuries present to emergency departments frequently. Pain secondary to these injuries is typically managed with opioids, which may be inadequate and have side effects. Ultrasound (US)-guided forearm nerve blocks have emerged as an alternative modality for patients with acute pain from isolated extremity injuries. Methods: We performed a non-blinded, consecutive, randomized pragmatic trial of US-guided forearm nerve blocks using medium and long-acting anesthetic versus usual care for a six-day period around July 4th, 2017. Adults who sustained a traumatic or blast injury of their hands were considered. Consecutive emergency department patients were consented, enrolled and randomized into a study group (block) or control (standard care). The study group received a US-guided forearm block using a 50/50 mix of 1% lidocaine and 0.5% bupivacaine. The primary outcome was median pain scores via a 100-point visual analog scale at 15, 60, and 120 minutes after the nerve block compared to the baseline pain score. The secondary outcome was mean morphine equivalents administered. Results: Sixteen patients were screened and 12 were randomized: six to the treatment group and six to the control group. Median pain reduction from baseline at 15, 60, and 120 minutes in the forearm block group was -35 (IQR=10), -30 (IQR=50), and -20 (IQR=70, versus -5 (IQR=10), -20.5 (IQR=20), -20 (IQR=70) in the control group. At all time points, patient-reported pain scores decreased significantly over baseline in the forearm block group, whereas non-significant reductions in pain scores occurred in the control group. Conclusion: US-guided forearm blocks for acute traumatic hand injuries resulted in greater pain relief when compared to usual care.

Purpose In hospital-based studies, patients intubated by physicians while in an inclined position compared to supine position had a higher rate of first pass success and lower rate of peri-intubation complications. We evaluated the impact of patient positioning on prehospital endotracheal intubation in an EMS system with rapid sequence induction capability. We hypothesized that patients in the inclined position would have a higher first-pass success rate. Methods Prehospital endotracheal intubation cases performed by paramedics between 2012 and 2017 were prospectively collected in airway registries maintained by a metropolitan EMS system. We included all adult (age ≥ 18 years) non-traumatic, non-arrest patients who received any attempt at intubation. Patients were categorized according to initial positioning: supine or inclined. The primary outcome measure was first pass success with secondary outcomes of laryngoscopic view and challenges to intubation. Results Of the 13,353 patients with endotracheal intubation attempted by paramedics during the study period, 4879 were included for analysis. Of these, 1924 (39.4%) were intubated in the inclined position. First pass success was 86.3% among the inclined group versus 82.5% for the supine group (difference 3.8%, 95% CI: 1.5%–6.1%). First attempt laryngeal grade I view was 62.9% in the inclined group versus 57.1% for the supine group (difference 5.8%, 2.0–9.6). Challenges to intubation were more frequent in the supine group (42.3% versus 38.8%, difference 3.5%, 0.6–6.3). Conclusion Inclined positioning was associated with a better grade view and higher rate of first pass success. The technique should be considered as a viable approach for prehospital airway management.

BACKGROUND International guidelines emphasize advanced airway management during out-of-hospital cardiac arrest (OHCA). We hypothesized that increasing endotracheal intubation attempts during OHCA were associated with a lower likelihood of favorable neurologic survival at discharge. METHODS This retrospective, observational cohort evaluated the relationship between number of intubation attempts and favorable neurologic survival among non-traumatic OHCA patients receiving cardiopulmonary resuscitation (CPR) from January 1, 2015-June 30, 2019 in a large urban emergency medical services (EMS) system. Favorable neurologic status at hospital discharge was defined as a Cerebral Performance Category score of 1 or 2. Multivariable logistic regression, adjusted for age, sex, witness status, bystander CPR, initial rhythm, and time of EMS arrival, was performed using the number of attempts as a continuous variable. RESULTS Over 54 months, 1205 patients were included. Intubation attempts per case were 1 = 757(63%), 2 = 279(23%), 3 = 116(10%), ≥4 = 49(4%), and missing/unknown in 4(

Background: Recent strides in computational structural biology have opened up an opportunity to understand previously uncharacterised proteins. The under-representation of transmembrane proteins in the Protein Data Bank highlights the need to apply new and advanced bioinformatics methods to shed light on their structure and function. This study focuses on a family of transmembrane proteins containing the Pfam domain PF09335 ('SNARE_ASSOC'/ ‘VTT ‘/’Tvp38’/'DedA'). One prominent member, Tmem41b, has been shown to be involved in early stages of autophagosome formation and is vital in mouse embryonic development as well as being identified as a viral host factor of SARS-CoV-2. Methods: We used evolutionary covariance-derived information to construct and validate ab initio models, make domain boundary predictions and infer local structural features. Results: The results from the structural bioinformatics analysis of Tmem41b and its homologues showed that they contain a tandem repeat that is clearly visible in evolutionary covariance data but much less so by sequence analysis. Furthermore, cross-referencing of other prediction data with covariance analysis showed that the internal repeat features two-fold rotational symmetry. Ab initio modelling of Tmem41b and homologues reinforces these structural predictions. Local structural features predicted to be present in Tmem41b were also present in Cl-/H+ antiporters. Conclusions: The results of this study strongly point to Tmem41b and its homologues being transporters for an as-yet uncharacterised substrate and possibly using H+ antiporter activity as its mechanism for transport.

BackgroundRigorous assessment of occupational COVID-19 risk and personal protective equipment (PPE) use are not well-described. We evaluated 9-1-1 emergency medical services (EMS) encounters for patients with COVID-19 to assess occupational exposure, programmatic strategies to reduce exposure, and PPE use.MethodsWe conducted a retrospective cohort investigation of lab-confirmed COVID-19 patients in King County, WA who received 9-1-1 EMS responses from February 14, 2020 to March 26, 2020. We reviewed dispatch, EMS, and public health surveillance records to evaluate the temporal relationship between exposure and programmatic changes to EMS operations designed to identify high-risk patients, protect the workforce, and conserve PPE.ResultsThere were 274 EMS encounters for 220 unique COVID-19 patients involving 700 unique EMS providers with 988 EMS person-encounters. Use of “full” PPE including mask, eye protection, gown and gloves (MEGG) was 67%. There were 151 person-exposures among 129 individuals, who required 981 quarantine days. Of the 700 EMS providers, 3 (0.4%) tested positive within 14 days of encounter. Programmatic changes were associated with a temporal reduction in exposures. When stratified at the study encounters midpoint, 94% (142/151) of exposures occurred during the first 137 EMS encounters compared to 6% (9/151) during the second 137 EMS encounters (pConclusionLess than 0.5% of EMS providers experienced COVID-19 illness within 14 days of occupational encounter. Programmatic strategies were associated with a reduction in exposures, while achieving a measured use of PPE.

Key Points Question What is the clinical presentation to emergency medical services among persons with coronavirus disease 2019 (COVID-19)? Findings This cohort study of 124 patients with COVID-19 revealed that most patients with COVID-19 presenting to emergency medical services were older and had multiple chronic health conditions. Initial concern, symptoms, and examination findings were heterogeneous and not consistently characterized as febrile respiratory illness. Meaning The findings of this study suggest that the conventional description of febrile respiratory illness may not adequately identify COVID-19 in the prehospital emergency setting., This cohort study describes patient characteristics and prehospital presentation of patients with coronavirus disease 2019 (COVID-19) cared for by emergency medical services (EMS) in King County, Washington., Importance The ability to identify patients with coronavirus disease 2019 (COVID-19) in the prehospital emergency setting could inform strategies for infection control and use of personal protective equipment. However, little is known about the presentation of patients with COVID-19 requiring emergency care, particularly those who used 911 emergency medical services (EMS). Objective To describe patient characteristics and prehospital presentation of patients with COVID-19 cared for by EMS. Design, Setting, and Participants This retrospective cohort study included 124 patients who required 911 EMS care for COVID-19 in King County, Washington, a large metropolitan region covering 2300 square miles with 2.2 million residents in urban, suburban, and rural areas, between February 1, 2020, and March 18, 2020. Exposures COVID-19 was diagnosed by reverse transcription–polymerase chain reaction detection of severe acute respiratory syndrome coronavirus 2 from nasopharyngeal swabs. Test results were available a median (interquartile range) of 5 (3-9) days after the EMS encounter. Main Outcomes and Measures Prevalence of clinical characteristics, symptoms, examination signs, and EMS impression and care. Results Of the 775 confirmed COVID-19 cases in King County, EMS responded to 124 (16.0%), with a total of 147 unique 911 encounters. The mean (SD) age was 75.7 (13.2) years, 66 patients (53.2%) were women, 47 patients (37.9%) had 3 or more chronic health conditions, and 57 patients (46.0%) resided in a long-term care facility. Based on EMS evaluation, 43 of 147 encounters (29.3%) had no symptoms of fever, cough, or shortness of breath. Based on individual examination findings, fever, tachypnea, or hypoxia were only present in a limited portion of cases, as follows: 43 of 84 encounters (51.2%), 42 of 131 (32.1%), and 60 of 112 (53.6%), respectively. Advanced care was typically not required, although in 24 encounters (16.3%), patients received care associated with aerosol-generating procedures. As of June 1, 2020, mortality among the study cohort was 52.4% (65 patients). Conclusions and Relevance The findings of this cohort study suggest that screening based on conventional COVID-19 symptoms or corresponding examination findings of febrile respiratory illness may not possess the necessary sensitivity for early diagnostic suspicion, at least in the prehospital emergency setting. The findings have potential implications for early identification of COVID-19 and effective strategies to mitigate infectious risk during emergency care.

Acute aortic dissection is a time-critical emergency that air medical teams must be capable of transporting. Aortic dissections can manifest a myriad of complications in which prompt recognition and tailored treatments may mitigate additional physiological burden and limit dissection flap propagation. The purpose of this review is to discuss specific critical scenarios that air medical providers may be faced with and to equip them with a pathophysiological understanding of the disease and best practices for the management of acute aortic dissections.

PURPOSE Diverted prescription opioids are significant contributors to drug overdose mortality. Street price has been suggested as an economic metric of the diverted prescription opioid black market. This study examined variables that may influence the street price of diverted oxycodone and oxymorphone. METHODS A cross-sectional study was conducted utilizing data from the previously validated, crowdsourcing website StreetRx. Street price reports of selected oxycodone and oxymorphone products, between August 22, 2014 and June 30, 2016, were considered for analysis. Geometric means and 95% confidence intervals were calculated comparing prices per milligram of drug in US dollars. Univariate and multivariable regressions were used to examine the influence of dosage strength, drug formulation, and bulk purchasing on street price. RESULTS A total of 5611 oxycodone and 1420 oxymorphone reports were analyzed. Across various dosages and formulations, geometric mean prices per milligram ranged between $0.12 and $1.07 for oxycodone and $0.73 and $2.90 for oxymorphone. For a 2-fold increase in dosage strength, there is a 24.0% (95% CI: -28.1%, -19.6%, P

The epidemic of prescription opioid overdose and mortality parallels the dispensing rates of prescription opioids, and the availability of increasingly potent opioid analgesics. The common assumption that more potent opioid analgesics are associated with higher rates of adverse outcomes has not been adequately substantiated. We compared the rate of serious adverse events among commonly prescribed opioid analgesics of varying potency. Serious adverse events (SAEs; defined as death, major medical effect, or hospitalization) resulting from exposure to tablets containing seven opioid analgesics (oxycodone, hydrocodone, morphine, hydromorphone, oxymorphone, tapentadol, and tramadol) captured by the Researched Abuse, Diversion and Addiction-Related Surveillance (RADARS®) System Poison Center Program were evaluated from 2010 through 2016. Rates of SAEs were adjusted for availability through outpatient dispensing data and regressed on morphine milligram equivalents (MME). There were 19,480 cases of SAE during the 7-year study period. Hydrocodone and oxycodone contributed to 77% of SAE cases. Comparing rates of outcome by relative potency, a hierarchy was observed with hydromorphone (8.02 SAEs/100 kg) and tapentadol (0.27 SAE/100 kg) as the highest and lowest rates, reflecting a 30-fold difference among individual opioid products. SAE rate and potency were related linearly—SAEs increased 2.04 per 100 kg drug dispensed for each 1-unit rise in MME (p = 0.004). Linear regression of SAE/100 kg drug dispensed and drug potency identified that MME comprised 96% of the variation observed. In contrast, potency did not explain variation seen using other study denominators (prescriptions dispensed, dosage units dispensed, and the number of individuals filling a prescription). Potency of a prescription opioid analgesic demonstrates a significant, highly positive linear relationship with exposures resulting in SAEs per 100 kg drug dispensed reported to poison centers. Potency should be carefully considered from both individual provider and public health perspectives.

Massive upper gastrointestinal hemorrhage represents a highly morbid, resource intensive disease entity that requires rapid diagnostic and therapeutic delivery in parallel with mobilization of in-hospital providers for definitive intervention. This report details a unique case demonstrating exceptional collaboration spanning multiple healthcare systems, a novel use of resuscitative endovascular balloon occlusion of the aorta, and a discussion on resuscitative airway management in the setting of massive upper gastrointestinal hemorrhage.

Objective To validate an ocular phantom as a realistic educational tool utilizing in vivo and phantom optic nerve sheath (ONS) images obtained by ultrasound. Methods This prospective study enrolled 51 resident physicians from the Denver Health Residency in Emergency Medicine (EM) and 10 ultrasound fellowship-trained EM attending physicians. Participants performed optic nerve sheath diameter (ONSD) measurements on five in vivo and five phantom ocular ultrasound images and rated the realism of each image on a 5-point Likert scale. Chi-square analysis was performed to evaluate the subjective “realness” of in vivo and phantom images. Results Sixty-one participants performed ONSD measurements. Mean Likert scale values were 3.43 (95% confidence interval: 3.31–3.55) for in vivo images and 3.41 (95% confidence interval: 3.28–3.54) for phantom images. There was no statistical difference in subjective “realness” between in vivo and phantom ONSD ultrasound images among EM residents. Ultrasound fellowship-trained EM attending physicians aptly differentiated between in vivo (p < 0.01) and phantom (p < 0.01) images, as compared with EM residents. Conclusion Our ocular phantom simulates in vivo posterior ocular anatomy. EM resident physicians found the phantom indistinguishable from in vivo images. Our ONS model provides an inexpensive and realistic educational tool to teach bedside ONSD sonography.

Objectives To compare the degree of agreement of sonographic optic nerve sheath diameter (ONSD) measurements by ultrasound fellowship–trained and resident emergency medicine (EM) physicians. Methods Ten ultrasound fellowship–trained EM attending physicians from multiple institutions and 51 resident EM physicians at a single residency were enrolled to measure the ONSD using a computerized ruler on five separate still-frame sonograms of adult eyes that included the retrobulbar optic nerve. Descriptive and bivariate statistics for each ultrasound image were calculated to compare median ONSD measurements among groups. Intraclass correlation coefficients (ICCs) were calculated to estimate the inter-rater reliability. Results Although the median ONSD measurement of each image did not significantly differ between resident and ultrasound fellowship–trained EM physicians, we found greater variation in agreement of ONSD measurements by resident EM physicians (ICC 0.50; 95% confidence interval 0.25–0.89) than ultrasound fellowship–trained EM physicians (ICC 0.73; 95% confidence interval 0.44–0.96). Conclusions Although both resident and ultrasound fellowship–trained EM physicians showed good inter-rater reliability of ONSD measurements, variation in agreement among ultrasound fellowship–trained EM physicians may be as wide as 0.44, suggesting that even in skilled hands, ultrasound measurement of the ONSD may not be as dependable a screening tool for elevated intracranial pressure as previously suggested in the literature.

While potassium cyanide poisoning has been well described, the toxicity of potassium gold cyanide is less well understood. This case describes an 84-year-old man who presented after an intentional ingestion of 0.5–1 teaspoons of potassium gold cyanide. Despite antidotal therapy, the patient rapidly developed severe lactic acidosis, multiorgan dysfunction and ultimately expired. While the patient’s clinical findings were consistent with acute cyanide poisoning, a serum cyanide level was below the toxic threshold. Previous reports have suggested that gold toxicity may also contribute to the effects of potassium gold cyanide, and may have played a role in the patient’s rapid decline. In addition to treatment of cyanide toxicity, management of acute gold toxicity should also be considered in potassium gold cyanide ingestion.

In the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (ROP), 4099 infants weighing less than 1251 g at birth underwent sequential ophthalmic examinations, beginning at age 4 to 6 weeks, to monitor the incidence and course of ROP. Overall, 65.8% of the infants developed ROP to some degree; 81.6% for infants of less than 1000 g birth weight. As expected, ROP incidence and severity were higher in lower birth weight and gestational age categories. Black infants appeared less susceptible to ROP, of all severity categories, than nonblack infants. The timing of retinal vascular events correlated more closely with postconceptional age than with postnatal age, implicating the level of maturity more than postnatal environmental influences in governing the timing of these vascular events. These results include the current incidence of various severity stages of ROP found in the United States and provide new. insight into the development of ROP.

The ultrastructure of left posterior papillary muscles isolated from adult guinea pigs was examined before and after 30 min of hypoxia. A rapid decline in developed tension was observed during early hypoxia but at the time of fixation the activity had stabilized at 29% of the prehypoxia value. Control muscles bathed only in oxygenated Tyrode's solution resembled intact muscle fixed in situ , except for the presence of more intramitochondrial granules. Hypoxic muscles showed no signs of severe damage. Myofibrils were normal except for widened Z bands. Mitochondria were very often swollen and seldom contained intramitochondrial granules. Since the disappearance of intramitochondrial granules was also observed in hypoxia, additional cytochemical studies were performed to determine the content of the intramitochondrial granules. Unstained sections of post-osmicated control and hypoxic muscle containing intramitochondrial granules were examined. The granules before and after the hypoxic period had an average diameter of 330 . Electron dense granules were not removed by decalcifying agents, 2% formic acid or 2 m m EDTA without prior oxidation by 5% periodic acid or 2% hydrogen peroxide. Inorganic material in granules was not seen after microincineration at 500°C. The intramitochondrial granules do not change in size, yet they increase in number after prolonged incubation in 95% oxygen and decrease in number in 95% nitrogen. The number of granules may be related to the availability of substrate for the organic matrix of the granules.

Progressive morphological changes have been quantitated in ischemic and control regions of canine hearts previously assessed biochemically and physiologically. Muscle strips removed after a 5 or 10-min occlusion of the left circumflex artery were compared to those removed after reperfusion for 20 or 60 min following 10 min occlusion and to those removed immediately from normal and sham-operated dogs. Decreased glycogen content and decreased mitochondrial matrix were observed in fibers from ischemic regions as early as 5 min after ligation. Changes in the mitochondrial volume fraction were calculated by the point counting method and changes in the number of lipid droplets per unit area were determined. Mitochondrial volume fractions in ischemic regions were not significantly higher when compared to control regions of the same hearts, and were similar to the values measured for 10 and 70-min sham-operated dogs. We conclude that in early acute ischemia considerable variability in the different control groups emerges with extensive sampling and must be considered in interpreting ultrastructural changes.

Enzymatically active cardiac sarcoplasmic reticulum (SR) fractions contain glycogen. Previous biochemical and morphological studies indicate that the glycogen particles are membrane associated. In the present study, further evidence for membrane-associated glycogen particles in these cardiac SR fractions is presented: (1) morphological parameters, (2) enzymatic digestion by glucoamylase and alpha-amylase and (3) cytochemical staining by two different methods. Dense granules comparable in size (20–30 nm diameter), electron density and substructure to glycogen particles observed in intact cardiac muscle and in glycogen preparations isolated from skeletal muscle were seen. Most of these glycogen particles were removed by amylase digestion except for glycogen particles closely adhering to vesicle membranes. Two different cytochemical techniques (bismuth subnitrate and silver proteinate) revealed a positive reaction product over the glycogen particles. These findings provide further support for the biochemical finding of a structured enzyme complex involving the SR, glycogenolytic enzymes and glycogen.

Injuries to the head have been steadily increasing in the past quarter of a century, and fractures of the mandible in particular have increased manyfold. The illustration (fig. 1) from Fomon's textbook 1 shows the various sites of fractures and the frequency of occurrence. While this is an accurate and standard chart, the present situation presents a more complex picture. The forces causing head injuries seem to be more intense, with the result that the fractures are frequently multiple and the displacement of the fragments extremely complicating. Broken jaws have been recorded in medical history since 3,000 B. C., according to Breasted's 2 translation of the Edwin Smith surgical papyrus. Since this recording of such an injury, there have been numerous methods of treatment. We have tried many of these with varying degrees of success. Until the advent of skeletal fixation. there has not been a universal method of treatment

Accidents of all types have been the cause of extensive research and surveys. Despite the commendable efforts of safety conferences in all fields, despite the fine educational program of the National Safety Council in our schools, the annual accident rate is, and will continue to be, high. With motor vehicles being responsible for the greatest number of accidents, these figures from the National Safety Council are pertinent. The total number of fatal accidents in 1946 was 33,700, an increase of 20 per cent over the preceding year and of 38 per cent over 1944. With the National Safety Council ratio commonly used, of 35 injuries to each death, the 1946 approximate total of nonfatal vehicle injuries is 1,200,000. With the continued increase in travel, the probable number of victims of motor accidents in need of prompt and efficient care is too appalling to estimate. Consequently, the need for providing this