Rhinoceros beetle (Trypoxylus dichotomus) cuticular hydrocarbons contain information about body size and sex.

Japanese rhinoceros beetle (Trypoxylus dichotomus) males have exaggerated horns that are used to compete for territories. Larger males with larger horns tend to win these competitions, giving them access to females. Agonistic interactions include what appears to be assessment and often end without escalating to physical combat. However, it is unknown what information competitors use to assess each other. In many insect species chemical signals can carry a range of information, including social position, nutritional state, morphology, and sex. Specifically, cuticular hydrocarbons (CHCs), which are waxes excreted on the surface of insect exoskeletons, can communicate a variety of information. Here, we asked whether CHCs in rhinoceros beetles carry information about sex, body size, and condition that could be used by males during assessment behavior. Multivariate analysis of hydrocarbon composition revealed patterns associated with both sex and body size. We suggest that Rhinoceros beetles could be communicating information through CHCs that would explain behavioral decisions.

Impact of Chemoprophylaxis on Thromboembolism Following Operative Fixation of Pelvic Fractures.

BACKGROUND: Venous thromboembolism (VTE) is a common cause of serious morbidity and mortality. While chemoprophylaxis decreases VTE, there is the theoretical risk of increased hemorrhagic complications. The purpose of this study was to evaluate the impact of preoperative anticoagulation on VTE and bleeding complications in patients with blunt pelvic fractures requiring operative fixation. METHODS: Patients with blunt pelvic fractures requiring operative fixation over 10.5 years were identified. Patients were stratified by age, severity of shock, operative management, and timing and duration of anticoagulation. Outcomes were evaluated to determine risk factors for bleeding complications and VTE. RESULTS: 310 patients were identified: 212 patients received at least one dose of preoperative anticoagulation and 98 received no preoperative anticoagulation. 68% were male with a mean injury severity score and Glasgow Coma Scale of 26 and 13, respectively. Bleeding complications occurred in 24 patients and 21 patients suffered VTE. Patients with VTE had a greater initial severity of shock (resuscitation transfusions, 4 vs. 2 units, P = .02). Despite longer time to mobilization (4 vs. 3 days, P = .001), patients who received their scheduled preoperative doses within 48 hours of arrival had no significant differences in the number of deep vein thrombosis events (5.2% vs. 5.7%, P = .99), but fewer episodes of pulmonary embolism (PE) (1.5% vs. 6.8%, P = .03) with no difference in bleeding complications (7.5% vs. 8%, P = .87) compared to either patients who had their doses held until after 48 hours of arrival or received no preoperative anticoagulation. DISCUSSION: Preoperative anticoagulation prior to pelvic fixation reduced the risk of PE without increasing bleeding complications. Preoperative anticoagulation is safe and beneficial in this group of patients.

Better Late than Never? Adherence to Adjuvant Therapy Guidelines for Stage III Colon Cancer in an Underserved Region.

INTRODUCTION: In 2008, the American College of Surgeons Commission on Cancer (CoC) issued a quality guideline for stage III colon cancer (CC) recommending adjuvant chemotherapy (AC) within 120 days of diagnosis. We examined adherence in a healthcare system serving a region with disparities in CC outcomes. METHODS: In a retrospective analysis of patients (2005-2014) with stage III CC in a multi-hospital healthcare system, the associations between adherence, clinicopathologic, demographic, geographic, and socioeconomic data and overall survival (OS) were examined. RESULTS: Of 1171 CC patients, 438 (37.4%) had stage III disease with 63% (n = 276) receiving AC and 37% (n = 162) not. AC conferred a 5-year OS advantage (62.4 vs. 42.5%, p < 0.0001). Younger age independently predicted AC receipt (OR = 0.95, p < 0.0001). Of 252 AC patients < 80 years, 75.8% were CoC guideline compliant (GC) whereas 24.2% were not (nGC). Although there was no OS difference between GC and nGC, both had superior survival (p < 0.0001) compared to non-AC patients. Surgical complications trended towards independent association with non-compliance (p = 0.07) CONCLUSION: Guideline compliance in our system (63%) is lower than the CoC Estimated Performance Rate (72.4%). Age influenced absolute receipt of AC while surgical complications may impact guideline compliance. Even when administered beyond 120 days, AC was associated with a survival benefit.

Goldmann tonometer error correcting prism: clinical evaluation.

PURPOSE: Clinically evaluate a modified applanating surface Goldmann tonometer prism designed to substantially negate errors due to patient variability in biomechanics. METHODS: A modified Goldmann prism with a correcting applanation tonometry surface (CATS) was mathematically optimized to minimize the intraocular pressure (IOP) measurement error due to patient variability in corneal thickness, stiffness, curvature, and tear film adhesion force. A comparative clinical study of 109 eyes measured IOP with CATS and Goldmann prisms. The IOP measurement differences between the CATS and Goldmann prisms were correlated to corneal thickness, hysteresis, and curvature. RESULTS: The CATS tonometer prism in correcting for Goldmann central corneal thickness (CCT) error demonstrated a reduction to <±2 mmHg in 97% of a standard CCT population. This compares to only 54% with CCT error <±2 mmHg using the Goldmann prism. Equal reductions of ~50% in errors due to corneal rigidity and curvature were also demonstrated. CONCLUSION: The results validate the CATS prism's improved accuracy and expected reduced sensitivity to Goldmann errors without IOP bias as predicted by mathematical modeling. The CATS replacement for the Goldmann prism does not change Goldmann measurement technique or interpretation.

1: 1 Transfusion strategies are right for the wrong reasons.

BACKGROUND: Early assessment of clot function identifies coagulopathies after injury. Abnormalities include a hypercoagulable state from excess thrombin generation, as well as an acquired coagulopathy. Efforts to address coagulopathy have resulted in earlier, aggressive use of plasma emphasizing 1:1 resuscitation. The purpose of this study was to describe coagulopathies in varying hemorrhagic profiles from a cohort of injured patients. METHODS: All injured patients who received at least one unit of packed red blood cells (PRBC) in the first 24 hours of admission from September 2013 to May 2015 were eligible for inclusion. Group-Based Trajectory Modeling, using volume of transfusion over time, was used to identify specific hemorrhagic phenotypes. The thromboelastography profile of each subgroup was characterized and group features were compared. RESULTS: Four hemorrhagic profiles were identified among 330 patients-minimal (MIN, group 1); patients with large PRBC requirements later in the hospital course (LH, group 2); massive PRBC usage (MH, group 3), and PRBC transfusion limited to shortly after injury (EH, group 4). All groups had an R-time shorter than the normal range (3.2-3.5, p = NS). Patients in group 3 had longer K-times (1.8 vs. 1.2-1.3, p < 0.05), significantly flatter α-angles (66.7 vs. 70.4-72.8, p < 0.05), and significantly weaker clot strength (MA 54.6 vs. 62.3-63.6, p < 0.05). Group 3 had greater physiologic derangements at admission and worse overall outcomes. CONCLUSION: Hemorrhagic profiles suggest a rapid onset of clot formation in all subgroups but significantly suppressed thrombin burst and diminished clot strength in the most injured. Patients are both hypercoagulable, with early and precipitous clot formation, and also have a demonstrable hypocoagulability. The exact cause of traumatic hypocoagulability is likely multifactorial. Goal-directed resuscitation, as early as institution of the massive transfusion protocol, may be more effective in resuscitating the most coagulopathic patients. LEVEL OF EVIDENCE: Prognostic study, level III.

Clot dynamics and mortality: The MA-R ratio.

INTRODUCTION: The coagulopathy of trauma, illustrated by a short R-time, is common and well understood. The physiology behind this may be early thrombin burst with rapid clot formation. Rapid consumption of fibrinogen, however, may result in weak clot and substrate depletion, resulting in low MA. While these characteristics are interesting, utilizing thromboelastography (TEG) to identify those at risk of subsequent bleeding diathesis, especially in those who do not demonstrate early signs of physiologic derangement, is challenging. We have developed a novel ratio utilizing TEG values to describe patients at specific risk of traumatic coagulopathy. The purpose of this study was to create a single TEG value, which would reflect both the hypercoagulability and hypocoagulability of TIC. We hypothesized that this ratio, at admission, would be indicative of TIC and predictive of both blood product transfusion volumes and subsequent mortality. METHODS: Patients admitted via the highest activation criteria at one of two Level I trauma centers were included if they received at least 1 unit of packed red blood cells in the first 24 hours of admission. The admission TEG was collected, and a ratio was calculated by dividing the MA by the R-time (MA-R). MA-R quartiles were developed, and multivariable logistic regression was utilized to determine odds of mortality. RESULTS: Three hundred thirty patients with admission TEG were included. In all patients, median age was 35 years (interquartile range, 25-54 years), Injury Severity Score (ISS) was 20 (interquartile range, 13-29), 76% were male, and 43% had penetrating trauma. The MA-R groups were based on quartiles. Multivariable analysis, controlling for mechanism of injury, ISS, and admission pH, showed that increasing ratios were associated with decreased odds of death. The lowest MA-R ratios were also significantly associated with higher ISS, higher rates of blunt injury, and higher plasma utilization without a significant difference in packed red blood cell administration. CONCLUSIONS: Patients with the lowest MA-R ratios demonstrated the highest mortality rates. This novel ratio may prove highly useful to predict at-risk patients early, when other physiologic indicators are absent. The mechanism driving this finding may rest in fibrinogen depletion, resulting in weak clot. Patients with low MA-R ratios may benefit from earlier resuscitation with cryoprecipitate, rather than the traditional use of plasma found in current massive transfusion protocols. LEVELS OF EVIDENCE: Prognostic study, Level I.

Goldmann Tonometer Prism with an Optimized Error Correcting Applanation Surface.

PURPOSE: We evaluate solutions for an applanating surface modification to the Goldmann tonometer prism, which substantially negates the errors due to patient variability in biomechanics. METHODS: A modified Goldmann or correcting applanation tonometry surface (CATS) prism is presented which was optimized to minimize the intraocular pressure (IOP) error due to corneal thickness, stiffness, curvature, and tear film. Mathematical modeling with finite element analysis (FEA) and manometric IOP referenced cadaver eyes were used to optimize and validate the design. RESULTS: Mathematical modeling of the optimized CATS prism indicates an approximate 50% reduction in each of the corneal biomechanical and tear film errors. Manometric IOP referenced pressure in cadaveric eyes demonstrates substantial equivalence to GAT in nominal eyes with the CATS prism as predicted by modeling theory. CONCLUSION: A CATS modified Goldmann prism is theoretically able to significantly improve the accuracy of IOP measurement without changing Goldmann measurement technique or interpretation. Clinical validation is needed but the analysis indicates a reduction in CCT error alone to less than ±2 mm Hg using the CATS prism in 100% of a standard population compared to only 54% less than ±2 mm Hg error with the present Goldmann prism. TRANSLATIONAL RELEVANCE: This article presents an easily adopted novel approach and critical design parameters to improve the accuracy of a Goldmann applanating tonometer.