Photorhabdus luminescens TccC3 Toxin Targets the Dynamic Population of F-Actin and Impairs Cell Cortex Integrity.

Due to its essential role in cellular processes, actin is a common target for bacterial toxins. One such toxin, TccC3, is an effector domain of the ABC-toxin produced by entomopathogenic bacteria of Photorhabdus spp. Unlike other actin-targeting toxins, TccC3 uniquely ADP-ribosylates actin at Thr-148, resulting in the formation of actin aggregates and inhibition of phagocytosis. It has been shown that the fully modified F-actin is resistant to depolymerization by cofilin and gelsolin, but their effects on partially modified actin were not explored. We found that only F-actin unprotected by tropomyosin is the physiological TccC3 substrate. Yet, ADP-ribosylated G-actin can be produced upon cofilin-accelerated F-actin depolymerization, which was only mildly inhibited in partially modified actin. The affinity of TccC3-ADP-ribosylated G-actin for profilin and thymosin-ß4 was weakened moderately but sufficiently to potentiate spontaneous polymerization in their presence. Interestingly, the Arp2/3-mediated nucleation was also potentiated by T148-ADP-ribosylation. Notably, even partially modified actin showed reduced bundling by plastins and α-actinin. In agreement with the role of these and other tandem calponin-homology domain actin organizers in the assembly of the cortical actin network, TccC3 induced intense membrane blebbing in cultured cells. Overall, our data suggest that TccC3 imposes a complex action on the cytoskeleton by affecting F-actin nucleation, recycling, and interaction with actin-binding proteins involved in the integration of actin filaments with each other and cellular elements.

Pseudomonas atacamensis sp. nov., isolated from the rhizosphere of desert bloom plant in the region of Atacama, Chile.

The bacterial strain M7D1T was isolated from samples of the rhizosphere of desert bloom plants on the Atacama region located in northern Chile as part of a study intended to isolate nitrifying bacteria in this adverse environment. It was previously identified as belonging to the Pseudomonas fluorescens group. In this study, the phylogenetic analysis of the 16s RNA, gyrA, rpoB and rpoD genes confirmed that this strain belongs to this group, especially Sub Group (SG) Koreensis, but it represents a potential new species. Additionally, the average nucleotide identity confirmed this as the highest identity value (0.92) with Pseudomonas moraviensis LMG 24280, which is lower than the 0.94 threshold established to classify two strains within the same species. The strain M7D1T shared a similar fatty acids methyl ester profile than the type strains of other Pseudomonas spp. previously described. Furthermore, it can be differentiated phenotypically from other related species of SG P. koreensis. Based on these results, the existence of a new species of Pseudomonas is demonstrated, for which the name Pseudomonas atacamensis is proposed. This strain presented a set of genes associated with plant growth-promoting rhizobacteria and it is a good candidate to be used for recovery of contaminated soils. However, more studies are required to demonstrate whether this bacterium is non-pathogenic, can survive in the presence of toxic compounds and promote growth or help to the stress management of plants.

An Analysis of Adherence to Tactical Combat Casualty Care Guidelines for the Administration of Tranexamic Acid.

BACKGROUND: Hemorrhage is the leading cause of potentially survivable deaths in combat. Previous research demonstrated that tranexamic acid (TXA) administration decreased mortality among casualties. For casualties expected to receive a transfusion, the Committee on Tactical Combat Casualty Care (TCCC) recommends TXA. Despite this, the use and adherence of TXA in the military prehospital combat setting, in accordance with TCCC guidelines, is low. OBJECTIVES: We sought to analyze TXA administration and use among combat casualties reasonably expected to require blood transfusion, casualties with tourniquet placement, amputations, and gunshot wounds. METHODS: Based on TCCC guidelines, we measured proportions of patients receiving prehospital TXA: casualties undergoing tourniquet placement, casualties sustaining amputation proximal to the phalanges, patients sustaining gunshot wounds, and patients receiving ≥10 units of blood products within 24 h of injury. Univariable and multivariable analyses were also completed. RESULTS: Within our dataset, 255 subjects received TXA. Four thousand seventy-one subjects had a tourniquet placed, of whom 135 (3.3%) received prehospital TXA; 1899 subjects had an amputation proximal to the digit with 106 (5.6%) receiving prehospital TXA; and 6660 subjects had a gunshot wound with 88 (1.3%) receiving prehospital TXA. Of 4246 subjects who received ≥10 units of blood products within the first 24 h, 177 (4.2%) received prehospital TXA. CONCLUSIONS: We identified low TXA administration despite TCCC recommendations. Future studies should seek to both identify reasons for limited TXA administration and methods to increase future utilization.

Notes from a field hospital south of Mosul.

This short letter from the field is offered as a rapid communiqué of the emergency medical situation in Mosul and surrounding areas on the eve of the final onslaught to liberate the city. This letter is based on emergency medical work at two World Health Organization (WHO) and Ministry of Health (MoH) Iraq lead Role II+ Field Hospital facilities south of Mosul City from April to June 2017; these facilities are currently and temporarily managed and administered by private medical industry until full handover to MoH Iraq, with WHO support and expert facilitation. The prominence of non-state actors in the conflict, using hybrid warfare tactics that maximize casualties, makes health security a particular challenge for the global community. This challenge requires health leaders and other actors in the region to set clear strategic goals that support public health of the many millions displaced, maimed and affected by the war. Whether in clinical medicine, development, peace and stability operations, or global health diplomacy, the shared values and conviction to best serve vulnerable communities and mitigate morbidity must embrace the lessons of evidenced based practice derived from military medical experience. WHO is leading the charge in disaster response for the conflict in Iraq, and many challenges remain. This might also include developing a new process in emergency medical response that utilizes private contracting to improve efficiency in delivery and overall sustainability.

Battlefield Analgesia in Tactical Combat Casualty Care.

At the start of the Afghanistan conflict, battlefield analgesia for US military casualties was achieved primarily through the use of intramuscular (IM) morphine. This is a suboptimal choice, since IM morphine is slow-acting, leading to delays in effective pain relief and the risk of overdose and death when dosing is repeated in order to hasten the onset of analgesia. Advances in battlefield analgesia, pioneered initially by Tactical Combat Casualty Care (TCCC), and the Army's 75th Ranger Regiment, have now been incorporated into the Triple-Option Analgesia approach. This novel strategy has gained wide acceptance in the US military. It calls for battlefield analgesia to be achieved using 1 or more of 3 options depending on the casualty's status: 1) the meloxicam and acetaminophen in the combat wound medication pack (CWMP) for casualties with relatively minor pain that are still able to function effectively as combatants if their sensorium is not altered by analgesic medications; 2) oral transmucosal fentanyl citrate (OTFC) for casualties who have moderate to severe pain, but who are not in hemorrhagic shock or respiratory distress, and are not at significant risk for developing either condition; or 3) ketamine for casualties who have moderate to severe pain, but who are in hemorrhagic shock or respiratory distress or are at significant risk for developing either condition. Ketamine may also be used to increase analgesic effect for casualties who have previously been given opioid medication. The present paper outlines the evolution and evidence base for battlefield analgesia as currently recommended by TCCC. It is not intended to be a comprehensive review of all prehospital analgesic options.

Tactical Combat Casualty Care: Beginnings.

Tactical Combat Casualty Care (TCCC) is a set of evidence-based, best-practice prehospital trauma care guidelines customized for use on the battlefield. The origins of TCCC were nontraditional. The TCCC program began as a Naval Special Warfare biomedical research effort launched after the realization that extremity hemorrhage, a leading cause of preventable death on the battlefield, was not being treated with a readily available and highly effective intervention: the tourniquet. This insight prompted a systematic reevaluation of all aspects of battlefield trauma care that was conducted from 1993 to 1996 as a joint effort by special operations medical personnel and the Uniformed Services University of the Health Sciences. The product of that 3-year research project was TCCC, the first-ever set of battlefield trauma care guidelines designed to combine good medicine with good small-unit tactics.

Integration of Tactical EMS in the National Park Service.

The National Park Service (NPS) has domestic responsibility for emergency medical services (EMS) in remote and sometimes tactical situations in 417 units covering over 34 million hectares (84 million acres). The crossover between conflicting patient care priorities and complex medical decision making in the tactical, technical, and wilderness/remote environments often has many similarities. Patient care in these diverse locations, when compared with military settings, has slightly different variables but often similar corresponding risks to the patients and providers. The NPS developed a Tactical EMS (TEMS) program that closely integrated many principles from: 1) Tactical Combat Casualty Care (TCCC); 2) Tactical Emergency Casualty Care (TECC); 3) and other established federal and civilian TEMS programs. Combining these best practices into the NPS TEMS Program allowed for standardized training and implementation across not only the NPS, but also paralleled other military/federal/civilian TEMS programs. This synchronization is critical when an injury occurs in a joint tactical operation, either planned (drug interdiction) or unplanned (active shooter response), so that patient care can be uniform and efficient. The components identified for a sustainable TEMS program began with strong medical oversight, protocol development with defined phases of care, identifying specialized equipment, and organized implementation with trained TEMS instructors. Ongoing TEMS program management is continuously improving situationally appropriate training and integrating current best practices as new research, equipment, and tactics are developed. The NPS TEMS Program continues to provide ongoing training to ensure optimal patient care in tactical and other NPS settings.

Translating Tactical Combat Casualty Care Lessons Learned to the High-Threat Civilian Setting: Tactical Emergency Casualty Care and the Hartford Consensus.

Combat operations necessitate bold thought and afford the opportunity to rapidly evolve and improve trauma care. The development and maturation of Tactical Combat Casualty Care (TCCC) is an important example of a critical process improvement strategy that reduced mortality in high-threat combat-related trauma. The Committee for Tactical Emergency Casualty Care (C-TECC) adapted the lessons of TCCC to the civilian high-threat environment and provided important all-hazards response principles for austere, dynamic, and resource-limited environments. The Hartford Consensus mobilized the resources of the American College of Surgeons to drive public policy regarding a more singular focus: hemorrhage control. The combined efforts of C-TECC and Hartford Consensus have helped redefine the practice of trauma care in high-threat scenarios across the United States.

The Transition to the Committee on Tactical Combat Casualty Care.

The original Tactical Combat Casualty Care (TCCC) guidelines were published in a special supplement to Military Medicine in 1996 as the terminal deliverable of a 2-year development project funded by the United States Special Operations Command (USSOCOM). Two years later, the USSOCOM Biomedical Initiatives Steering Committee (BISC) promulgated its Task Statement 5-98, in which it called for the formation of a panel of subject matter experts to update the TCCC guidelines. This article discusses the formation of the Committee on Tactical Combat Casualty Care (CoTCCC) and the changes to the original guidelines that constituted the first update.

Forward surgical care: Emerging issues and challenges.

War strategies have been evolving with time and battlefield casualty care services have been trying to keep pace with the changing demands. Technological advances in the field of trauma care have revolutionised the way in which erstwhile 'non-salvageable' lives and limbs are managed with more favourable outcome. The quality of Pre-Hospital Trauma Care Services will largely determine the survival statistics of battle casualties. The surgeon has to acknowledge the various resource constraints imposed upon him in the course of delivery of expert trauma care in the battlefield. The philosophy of Tactical Field Care and TACEVAC has, to a great extent, standardized point-of-care services and the manner in which combat casualties are managed. This has resulted in increasing favourable clinical outcome in a demanding, resource restricted and challenging environment. Training of Military Surgeons prior to induction into theatres of combat is an operational imperative and has to be based on validated guidelines promulgated by apex institutes specialised in Combat Casualty Care. CASEVAC hurdles, resource paucity, command and tactical decisions, govern casualty care and impose serious constraints that are not present in an urban setting. This article highlights the basic tenets of battlefield care, the challenges associated with it and the way forward.

[Modern methods of prehospital bleeding management based on the experience and standards of tactical medicine]. / Wspólczesne metody tamowania krwotoku w warunkach przedszpitalnych w oparciu o doswiadczenia i standardy medycyny taktycznej.

Isolated limb hemorrhage represents 60% of avoidable deaths and remains the leading cause of death in combat zone. Ideal tourniquet must be light, durable and cheap. They should completely stop the flow of arterial blood in the limb, and their attachment should be quick and easy. Tourniquets applied in correct location save lives by stopping the bleeding. Their use in civil environment appear to be particularly relevant in the mass casualties events. Modern bandages used by the military, were designed mostly in the form of an elastic bandage, which attachment has to be easy and quick. Sequential wrapping of elastic dressing around the wound produces compressive force which aim is to stem the bleeding by pressing vessel from the outside. Dressings are made of materials which adhere well to the wound, causing the seal and leave no fragments in the injured tissue. The combination of all components enables fast and effective application of the dressing in the most demanding conditions.

[Advanced methods of prehospital bleeding management based on the experience and standards of tactical medicine]. / Zaawansowane metody tamowania krwotoku w warunkach przedszpitalnych w oparciu o doswiadczenia i standardy medycyny taktycznej.

Hemostatic agents are currently used in the form of special granules or soaked gauze. Their use is particularly advantageous in difficult body location (e.g. on neck, armpit or groin), where other methods of bleeding control are impossible to use or fail. In a tactical environment tranexamic acid received first class recommendation for use in case of severe bleeding in the US Army. Its application should be considered in case of traumatic amputation, penetrating chest and abdominal trauma or hemorrhagic shock. The aim of the implementation of hypotensive resuscitation is to maintain perfusion of vital organs in patient with hypovolemia, without excessive fluid infusion. Modern method of bleeding control in combat condition are compression clamps. The purpose of these devices is to compress blood vessel by external pressure pads, especially in difficult to access arteries and large veins in the pelvis or in the distal abdominal aorta.

Comparison of supraglottic airway laryngopharyngeal tube, oropharyngeal and nasopharyngeal airway use by Polish soldiers on the manikin with difficult airway.

UNLABELLED: Airway obstruction represents 6% of avoidable deaths in a combat zone. Statistical analysis of deaths in the battlefield during combat missions in Iraq and Afghanistan shows that 1% of the soldiers are killed because of airway obstruction. The aim of the study was to objectively evaluate the use of S.A.L.T. (Supraglottic Airway Laryngopharyngeal Tube), oropharyngeal airway (OPA) and nasopharyngeal airway (NPA) on the manikin with difficult airway to assess the risk of air introduction into the stomach during ventilation trauma patient and time of insertion of each device. MATERIAL AND METHODS: A prospective study was conducted with the participation of 34 soldiers of the Polish Armed Forces (PAF). They ventilated a manikin using testing devices, to assess the volume of air entering the lungs and the stomach we used specially constructed flowmeters. The mean and median values of all measurements were calculated and compared by means of the Student's t test. RESULTS: 102 device placements and 204 ventilations were performed and evaluated during the study. The median time required for placement of S.A.L.T. was 12.44 sec vs 13.32 sec for NPA vs 9,34 sec for OPA (p<0.05). Mean volumes of air entering the lungs and stomach during ventilation with S.A.L.T. were (ml) 194.23 and 166 respectively, for NPA 218.13 vs 200.93 and for OPA 197.47 vs 169.22. CONCLUSIONS: Total volume of air entering into the stomach using S.A.L.T. was the lowest among all three devices. The use of NPA did not show any clinically important advantage, the fastest insertion time for OPA may be of value in the battlefield.

Evaluation of fluid bolus administration rates using ruggedized field intravenous systems.

OBJECTIVE: The purpose of this study was to evaluate 2 ruggedized field intravenous (IV) systems currently in use by US military medics and to determine their effect on fluid bolus administration rates. METHODS: A series of 500 mL fluid boluses consisting of either Lactated Ringer's solution or Hextend were delivered to 2 artificial intravenous training arms using a standard 18G catheter (control) and 2 separate ruggedized field IV systems. Fluid boluses were delivered under both gravity force and pressure infusion (constant 300 mm Hg), and total bolus times were recorded. RESULTS: Using Lactated Ringer's solution, the standard IV system took a mean time of 9:33 minutes (95% CI: 9:13-9:54) to deliver a 500 mL fluid bolus whereas the 2 ruggedized field systems took mean times of 14:50 minutes (95% CI: 14:00-15:40) and 12:20 minutes (95% CI: 11:54-12:45). Using Hextend, the mean bolus time for the control system was 24:39 minutes (95% CI: 22:47-26:32). The 2 ruggedized field systems required an average of 49:32 minutes (95% CI: 48:07-50:58) and 39:46 minutes (95% CI: 37:30-42:01) to deliver an equivalent bolus. Pressure infusion significantly increased flow rate in all systems. CONCLUSIONS: Ruggedized field IV systems can significantly delay fluid bolus rates. In instances where ruggedized field systems are deemed necessary, pressure infusion devices should be considered to overcome the constrictive effects of the ruggedized system.

Audit and Inventory of Federal Law Enforcement Agency Tactical Medic Bags.

Separate evidence-based, best practice guidelines and recommendations exist for the prehospital management of traumatic injuries sustained in combat settings and those encountered during high-threat civilian operational incidents. The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) Tactical Medic Program is a mature operational medicine asset supporting high-threat federal law enforcement operations. The ATF conducted an audit of its agency-issued tactical medic bags with regards to completeness, as defined by authorized medical protocols, which are aligned with current Tactical Combat Casualty Care and Tactical Emergency Casualty Care guidelines.

Where There's a War, There's a Way: A Brief Report on Tactical Combat Casualty Care Training in a Multinational Environment.

BACKGROUND: With most combat deaths occurring in prehospital settings, the US Armed Forces focuses on life-threatening conditions at or near the point of injury. Tactical Combat Casualty Care (TCCC) guidelines are required for all US Servicemembers. Multinational militaries lack this requirement, and international partner forces often have limited prehospital medical training. METHODS: From November 2019 to March 2020, military members assigned to the Role 2E at the Hamid Kazai International Airport (HKIA) North Atlantic Treaty Organization (NATO) base conducted multinational TCCC training. The standardized Joint Trauma System (JTS) TCCC curriculum consisted of two-day classroom instruction and situational training exercises. Competency was assessed through verbalized and demonstrated knowledge. After Action Reviews (AAR) were completed. RESULTS: Twelve multinational TCCC training courses trained 590 military Servicemembers and civilians from 10 countries, ranging from 16 to 62 participants (avg class size = 35). Portugal and Turkey represented the two largest participating nations with 219 and 133, respectively. Student feedback determined optimal group ratios for instruction. AARs were reviewed to categorize best practices. CONCLUSION: Multinational TCCC standardization will save lives. Most nations lack TCCC training requirements. Thus, providing opportunities for standardized training for HKIA residents helped established a multinational baseline of medical interoperability. Utilizing this curriculum in multinational environments can replicate these results. International adoption of TCCC is dynamic and ongoing and should be promulgated to reduce preventable deaths.

Bluetooth Tactical Headsets Improve The Speed of Accurate Patient Handoffs.

BACKGROUND: The Committee on En Route Combat Casualty Care recently ranked the patient handoff as their fourth research priority. Bluetooth technology has been introduced to the battlefield and has the potential to improve the tactical patient handoff. The purpose of this study is to compare the traditional methods of communication used in tactical medical evacuation by Special Operations medical personnel (radio push-to-talk [PTT] and Tactical Medic Intercom System [TM-ICS]) to Bluetooth communication. METHODS: Twenty-four simulated tactical patient handoffs were performed to compare Bluetooth and traditional methods of communication used in tactical medical evacuation. Patient scenario order and method of communication were randomized. Accuracy and time required to complete the patient handoff were determined. The study took place using a rotary-wing aircraft kept at level 2 to simulate real-world background noise. Preferred method of communication for each study participant was determined. RESULTS: There were no differences in accuracy of the received patient handoffs between groups or patient handoff transmission times at the ramp of the aircraft. However, when comparing patient handoff times to the medical team within the aircraft, Bluetooth communication was significantly faster than both TM-ICS and radio PTT, while Bluetooth PTT and radio PTT were also significantly faster than TM-ICS. Bluetooth communication was ranked as the preferred method of handoff by all study participants. CONCLUSION: The study demonstrated that utilization of Bluetooth technology for patient handover results in faster handoffs compared with traditional methods without sacrificing any accuracy in a scenario with high levels of noise.

Casualty evacuation in arctic and extreme cold environments: A paradigm shift for traumatic hypothermia management in tactical combat casualty care.

In Arctic or extreme cold environments of Alaska, trauma care is complicated by large expanses of geography and lack of forward-positioned resources. This paper presents four hypothetical vignettes highlighting austere cold medical priorities: (1) traumatic hypothermia management as part of Tactical Combat Casualty Care (TCCC) is clinically and tactically important and hypothermia needs to be reprioritized in the MARCH algorithm to MhARCH; (2) at present it is unknown which TCCC recommended medical equipment/supplies will function as designed in the extreme cold; (3) ensuring advanced resuscitative care measures are available serves as a temporal bridge until casualties can receive damage control resuscitation (DCR); and (4) current systems for managing traumatic hypothermia in TCCC and casualty evacuation (CASEVAC) are insufficient. In conclusion, numerous assessments recognise the DoD's current solutions for employing medical forces in Arctic operations are not optimally postured to save lives. There should be a joint standard for fielding an arctic supplement to current medical equipment sets. A new way of thinking in terms of an "ecosystem" approach of immediate casualty protection and movement in CASEVAC doctrine is needed to optimise these "Golden Minutes."

Analgesia and Sedation for Tactical Combat Casualty Care: TCCC Proposed Change 21-02.

Analgesia in the military prehospital setting is one of the most essential elements of caring for casualties wounded in combat. The goals of casualty care is to expedite the delivery of life-saving interventions, preserve tactical conditions, and prevent morbidity and mortality. The Tactical Combat Casualty Care (TCCC) Triple Option Analgesia guideline provided a simplified approach to analgesia in the prehospital combat setting using the options of combat medication pack, oral transmucosal fentanyl, or ketamine. This review will address the following issues related to analgesia on the battlefield: 1. The development of additional pain management strategies. 2. Recommended changes to dosing strategies of medications such as ketamine. 3. Recognition of the tiers within TCCC and guidelines for higher-level providers to use a wider range of analgesia and sedation techniques. 4. An option for sedation in casualties that require procedures. This review also acknowledges the next step of care: Prolonged Casualty Care (PCC). Specific questions addressed in this update include: 1) What additional analgesic options are appropriate for combat casualties? 2) What is the optimal dose of ketamine? 3) What sedation regimen is appropriate for combat casualties?

Cric in the Dark: Surgical Cricothyrotomy in Low Light Tactical Environments.

BACKGROUND: Surgical cricothyrotomy (SC) is a difficult procedure with high failure rates in the battlefield environment. The difficulty of this procedure is compounded in a low-light tactical environment in which white light cannot be used. This study compared the use of red-green (RG) light and red (R) light in the performance of SC in a low-light environment. MATERIALS AND METHODS: Tactical Combat Casualty Care-certified navy corpsmen (n = 33) were provided 15 minutes of standardized instruction followed by hands-on practice with the Tactical CricKit and the H&H bougie-assisted Emergency Cricothyrotomy Kit. Participants acclimated to a dark environment for 30 minutes before performing SC on a mannequin with both devices using both R and RG light in a randomized order. Application time, success, participant preference, and participant confidence were analyzed. RESULTS: There were similarly high levels of successful placement (>87.5%) in all four cohorts. Light choice did not appear to affect placement time with either of the two kits. On Likert-scale surveys, participants reported that RG decreased difficulty (p < .0001) and increased confidence (p < .0001) in performing the procedure. CONCLUSION: RG light increased confidence and decreased perceived difficulty when performing SC, though no differences in placement time or success were observed.