The Evolution of Fangs, Venom, and Mimicry Systems in Blenny Fishes

Venom systems have evolved on multiple occasions across the animal kingdom, and they can act as key adaptations to protect animals from predators. Consequently, venomous animals serve as models for a rich source of mimicry types, as non-venomous species benefit from reductions in predation risk by mimicking the coloration, body shape, and/or movement of toxic counterparts. The frequent evolution of such deceitful imitations provides notable examples of phenotypic convergence and are often invoked as classic exemplars of evolution by natural selection. Here, we investigate the evolution of fangs, venom, and mimetic relationships in reef fishes from the tribe Nemophini (fangblennies). Comparative morphological analyses reveal that enlarged canine teeth (fangs) originated at the base of the Nemophini radiation and have enabled a micropredatory feeding strategy in non-venomous Plagiotremus spp. Subsequently, the evolution of deep anterior grooves and their coupling to venom secretory tissue provide Meiacanthus spp. with toxic venom that they effectively employ for defense. We find that fangblenny venom contains a number of toxic components that have been independently recruited into other animal venoms, some of which cause toxicity via interactions with opioid receptors, and result in a multifunctional biochemical phenotype that exerts potent hypotensive effects. The evolution of fangblenny venom has seemingly led to phenotypic convergence via the formation of a diverse array of mimetic relationships that provide protective (Batesian mimicry) and predatory (aggressive mimicry) benefits to other fishes. Our results further our understanding of how novel morphological and biochemical adaptations stimulate ecological interactions in the natural world

Raptor wing morphing with flight speed

In gliding flight, birds morph their wings and tails to control their flight trajectory and speed. Using high-resolution videogrammetry, we reconstructed accurate and detailed three-dimensional geometries of gliding flights for three raptors (barn owl, Tyto alba; tawny owl, Strix aluco, and goshawk, Accipiter gentilis). Wing shapes were highly repeatable and shoulder actuation was a key component of reconfiguring the overall planform and controlling angle of attack. The three birds shared common spanwise patterns of wing twist, an inverse relationship between twist and peak camber, and held their wings depressed below their shoulder in an anhedral configuration. With increased speed, all three birds tended to reduce camber throughout the wing, and their wings bent in a saddle-shape pattern. A number of morphing features suggest that the coordinated movements of the wing and tail support efficient flight, and that the tail may act to modulate wing camber through indirect aeroelastic control

Minimal stress shielding with a Mallory-Head titanium femoral stem with proximal porous coating in total hip arthroplasty

<p>Abstract</p> <p>Background</p> <p>As longevity of cementless femoral components enters the third decade, concerns arise with long-term effects of fixation mode on femoral bone morphology. We examined the long-term consequences on femoral remodeling following total hip arthroplasty with a porous plasma-sprayed tapered titanium stem.</p> <p>Methods</p> <p>Clinical data and radiographs were reviewed from a single center for 97 randomly selected cases implanted with the Mallory-Head Porous femoral component during primary total hip arthroplasty. Measurements were taken from preoperative and long-term follow-up radiographs averaging 14 years postoperative. Average changes in the proximal, middle and diaphyseal zones were determined.</p> <p>Results</p> <p>On anteroposterior radiographs, the proximal cortical thickness was unchanged medially and the lateral zone increased 1.3%. Middle cortical thickness increased 4.3% medially and 1.2% laterally. Distal cortical thickness increased 9.6% medially and 1.9% laterally. Using the anteroposterior radiographs, canal fill at 100 mm did not correlate with bony changes at any level (Spearman's rank correlation coefficient of -0.18, 0.05, and 0.00; p value = 0.09, 0.67, 0.97). On lateral radiographs, the proximal cortical thickness increased 1.5% medially and 0.98% laterally. Middle cortical thickness increased 2.4% medially and 1.3% laterally. Distal cortical thickness increased 3.5% medially and 2.1% laterally. From lateral radiographs, canal fill at 100 mm correlated with bony hypertrophy at the proximal, mid-level, and distal femur (Spearman's rank correlation coefficient of 0.85, 0.33, and 0.28, respectively; p value = 0.001, 0.016, and 0.01, respectively).</p> <p>Conclusion</p> <p>Stress shielding is minimized with the Mallory-Head titanium tapered femoral stem with circumferential proximal plasma-sprayed coating in well-fixed and well-functioning total hip arthroplasty. Additionally, the majority of femora demonstrated increased cortical thickness in all zones around the stem prosthesis. Level of Evidence: Therapeutic Level III.</p

Age and frailty are independently associated with increased COVID-19 mortality and increased care needs in survivors: results of an international multi-centre study

INTRODUCTION: Increased mortality has been demonstrated in older adults with COVID-19, but the effect of frailty has been unclear.METHODS: This multi-centre cohort study involved patients aged 18years and older hospitalised with COVID-19, using routinely collected data. We used Cox regression analysis to assess the impact of age, frailty, and delirium on the risk of inpatient mortality, adjusting for sex, illness severity, inflammation, and co-morbidities. We used ordinal logistic regression analysis to assess the impact of age, Clinical Frailty Scale (CFS), and delirium on risk of increased care requirements on discharge, adjusting for the same variables.RESULTS: Data from 5,711 patients from 55 hospitals in 12 countries were included (median age 74, IQR 54-83; 55.2% male). The risk of death increased independently with increasing age (&gt;80 vs 18-49: HR 3.57, CI 2.54-5.02), frailty (CFS 8 vs 1-3: HR 3.03, CI 2.29-4.00) inflammation, renal disease, cardiovascular disease, and cancer, but not delirium. Age, frailty (CFS 7 vs 1-3: OR 7.00, CI 5.27-9.32), delirium, dementia, and mental health diagnoses were all associated with increased risk of higher care needs on discharge. The likelihood of adverse outcomes increased across all grades of CFS from 4 to 9.CONCLUSIONS: Age and frailty are independently associated with adverse outcomes in COVID-19. Risk of increased care needs was also increased in survivors of COVID-19 with frailty or older age

Between Commerce and Empire: David Hume, Colonial Slavery, and Commercial Incivility

Eighteenth-century Enlightenment thought has recently been reclaimed as a robust, albeit short-lived, cosmopolitan critique of European imperialism. This essay complicates this interpretation through a study of David Hume’s reflections on commerce, empire and slavery. I argue that while Hume condemned the colonial system of monopoly, war and conquest, his strictures against empire did not extend to colonial slavery in the Atlantic. This was because colonial slavery represented a manifestly uncivil institution when judged by enlightened metropolitan sensibilities, yet also a decisively commercial institution pivotal to the eighteenth-century global economy. Confronted by the paradoxical ‘commercial incivility’ of modern slavery, Hume opted for disavowing the link between slavery and commerce, and confined his criticism of slavery to its ancient, feudal and Asiatic incarnations. I contend that Hume’s disavowal of the commercial barbarism of the Atlantic economy is part of a broader ideological effort to separate the idea of commerce from its imperial origins and posit it as the liberal antithesis of empire. The implications of analysis, I conclude, go beyond the eighteenth-century debates over commerce and empire, and more generally pertain to the contradictory entwinement of liberalism and capitalism

A Retrospective Chart Review to Determine Lateral Ankle Instability Treatment based off of the Degree of Varus Tilt

Category: Ankle Introduction/Purpose: One of the most common injuries in the United States is the ankle sprain, accounting for 10-15% of sport injuries. Without proper treatment, about one-third of patients reinjure the same ankle and can progress to chronic lateral ankle instability. An ankle can be clinically evaluated by performing an inversion stress test and measuring the degree of varus tilt. The purpose of this retrospective chart review was to examine if a correlation exists between the degree of varus tilt on a stress x-ray and whether the patients were treated conservatively or surgically. Additionally, this chart review aims to confirm the validity of the guidelines of an abnormal talar tilt value, which is said to be a value greater than 10 degrees. Methods: A total of 584 patients between January 1st, 2016 and June 27th, 2019 were clinically diagnosed with lateral ankle instability and had an inversion stress x-ray. All 584 patients were seen and diagnosed by the same foot and ankle orthopedic surgeon in Columbus, Ohio. Of the 584 patients, 40 had bilateral lateral ankle instability and bilateral stress xrays, given a total of 624 ankles originally included in this chart review. Once the patient’s charts were reviewed, 32 ankles were excluded because their ankle surgery did not involve correction of the lateral ankle instability. A total of 592 ankles (293 left and 299 right) were included in this review. The degree of varus tilt on all 592 ankles were determined by measuring the angle between the tibial plafond and the top of the talus. The angles were compared to the patients with surgical and conservative treatment. Results: The chart review showed that as the degree of varus tilt increases, the more likely the patient is to fail conservative treatment and need surgical correction. The types of conservative treatment that the patients failed were a combination of a brace, boot, physical therapy, orthotics, shoe changes, injection, and casting. The patients who had a varus tilt below 2.5 degrees were treated conservatively 60% of the time, where patients that had a varus tilt over 20.1 degrees were treated surgically 75% of the time. The review also showed a significant number of patients who were treated surgically with a varus tilt value less than 10 degrees (209 of 472 ankles), warranting further evaluation into what is considered an abnormal talar tilt. Conclusion: It is clear that patients with a higher degree of varus tilt have more ankle instability and are more likely to fail conservative treatment and require surgical correction. Additionally, this chart review showed that many patients needed surgical correction even with a low varus tilt value on stress x-ray. Further evaluation needs to be completed to determine what value is considered an abnormal varus tilt. One possible explanation of our findings is that the inversion stress test does not evaluate the subtalar joint, which can contribute to chronic lateral ankle instability. </jats:sec

A Retrospective Chart Review to Examine Failed Modified Brostrom Procedures for Chronic Lateral Ankle Instability

Category: Ankle; Other Introduction/Purpose: Recurrent ankle injuries can lead to chronic ankle instability requiring surgical stabilization. Since the anterior talofibular ligament (ATFL) is the weakest of the lateral ankle ligaments, repair is often required in cases of chronic lateral ankle instability. Damage to the calcaneofibular ligament (CFL) is less common than the ATFL, but additional repair of it in these cases may be necessary to avoid this recurrent instability. A modified Brostrom procedure has been a widely accepted surgical approach to chronic lateral ankle instability if conservative measures fail. However, cases of recurrent instability even after initial stabilization surgery can present. The purpose was to examine reasoning for and rate of revision surgeries attempting to fix chronic lateral ankle instability as it relates to the ATFL and CFL integrity. Methods: A retrospective chart review was conducted to assess outcomes of a modified Brostrom procedure to determine underlying reasoning of the need for revision surgery by utilizing results of the anterior drawer and varus tilt tests. The files of these patients were examined via electronic health records to determine the reasoning for surgery. The preoperative and postoperative results of the anterior drawer test (ADT) and varus tilt test were used to examine ATFL and CFL integrity, respectively, in addition to operative notes. Results: 172 patients met criteria having undergone a modified Brostrom dual ligament repair procedure for lateral ankle instability by a single orthopedic foot and ankle surgeon. With a 3.49% revision rate in the patient population, the only similarity found in all of the patients was the presence of a positive varus tilt test indicating the CFL was a major contributor of failed correction via the modified Brostrom procedure. One patient had a positive ADT, and one had a mildly positive ADT. These ADT and varus tests were performed at various time points in the care of the patients. The average length between surgeries was calculated to be 624.2 days. This revision rate is higher than past studies but was limited to a few years under examination. Conclusion: In conclusion, the anterior drawer and varus tilt tests are utilized to determine the integrity of the ATFL and CFL in the lateral ankle ligament complex. In failed modified Brostrom procedures examined, the positive result was consistently in the varus tilt test, indicating that the CFL is the ligament most affected in these patients requiring additional surgery. However, these physical exam tests are only one way to examine the ankle and do not take additional pathologies of the lateral ankle into account. Additional studies are needed to examine long-term outcomes of the modified Brostrom procedure and reasoning for failure. </jats:sec

A Retrospective Chart Review to Examine Intra-Compartment Pressures and Post-Operative Outcomes of Chronic Exertional Compartment Syndrome

Category: Other Introduction/Purpose: Chronic exertional compartment syndrome (CECS) is defined as reversible, insufficient blood supply to a fascial compartment’s contents. Patients with this condition have abnormally elevated pressures within specific fascial compartments, causing decreased blood flow to that area. This temporary loss of blood supply produces a feeling of tightness in the affected muscles, pain, and possibly local paresthesia. Surgical treatment involves a fasciotomy, which releases the implicated compartment’s fascia. This procedure creates additional space for muscle expansion and more adequate blood supply to the appropriate tissues.The purpose of this study is to review the surgical outcomes of patients diagnosed with lower extremity CECS whom received a fasciotomy, assessing correlations between resting intramuscular compartment pressures and surgical outcomes. Methods: A retrospective chart analysis was performed of the senior author’s patients between January 1st, 2013 and June 30th, 2019. Patients included in this study presented with symptoms consistent with lower extremity CECS and had the diagnosis confirmed, either unilaterally or bilaterally, via the resting intramuscular pressure cutoff (&gt;=15 mmHg) outlined by the Pedowitz criteria. These patients subsequently received fasciotomies for the syndrome. Results: Out of the 37 patients included in this study, 30 (81.1%) reported improvement in their post-operative pain scores. There was a trend (P &gt; 0.1523) between resting intra-compartment pressures and post-operative pain improvement. Conclusion: Our study suggests a positive trend between higher resting intra-compartment pressures and post-operative pain improvement. Due to the limited number of study participants, no correlations could be determined. However, this data is significant because it demonstrates the importance of the Pedowitz diagnostic criteria, as it is the first study showing a relationship between the resting pressure criteria and surgical outcomes. Further research is necessary to determine if there is a correlation between higher intramuscular pressures and positive surgical outcomes. </jats:sec

A Retrospective Chart Review Examining Gabapentin’s Potential Neuroprotective Effects in Peripheral Nerve Blocks

Category: Other Introduction/Purpose: Regional anesthesia is routinely used in association with outpatient surgical procedures to mitigate postoperative pain. This has been associated with better surgical outcomes and decreased post-surgical opioid consumption. Administration of a nerve block; however, can lead to complications. These complications are typically due to nerve damage caused by the injection and leading to lasting neurologic symptoms unrelated to the surgical procedure itself. Although nerve block complications are rare and temporary, lasting complications can be debilitating. Based upon a few total knee arthroplasty studies this study theorized that Gabapentin could be used as a neuroprotectant thereby decreasing the rates of lasting complications from peripheral nerve blocks. This study compares the number of nerve block complications with and without the use of Gabapentin peri/post operatively. Methods: This study was completed through retrospective chart analysis of the senior author’s patients from January 2019 to September 2019. Charts of patients that received a preoperative nerve block were used to calculate rates of lasting complications. The rate of complications in this subset of patients was compared to the group of patients who did not receive this medication pre and post operatively from an earlier study. Results: Nerve block complication rates when administering 600mg of gabapentin 1-hour pre-surgery along with 100 mg of gabapentin three times daily for three days post-surgery, was 7.69% (N = 78; P=0.4261). However, there was an insufficient number of study participants to make a definitive conclusion. Conclusion: Administration of pre and post-operative gabapentin does not decrease nerve block complication rates when compared to no pre and post-operative gabapentin to a statistically significant amount. This was largely due to limited sample size, which was a major limitation of this study. A previous study was done with the same physician and the same patient population. In this study they found a 10.1% complication rate, seen in the evaluation of 855 patients charts. Due to a discrepancy in sample size, a conclusion cannot be made but further research is necessary to understand gabapentin’s potential neuroprotective effects in nerve blocks. </jats:sec