bluuebunny/crossref_metadata_2025 huggingface dataset:
Pulmonary Root Mobilization and Modified Lecompte Maneuver for Transseptal Course of the Left Main Coronary Artery
Authors: Said Sameh M. , Cetta Frank
Published: November 2020

Intraconal or transseptal course of the left main coronary artery is a rare form of coronary artery anomalies which has been linked to sudden death. We present details of the surgical technique that we used to address this challenging anomaly in two cases.
CABG With Internal Thoracic Artery in Children With Congenital Heart Defects: A Good Option When It Is the Only One
Authors: Kreutzer Christian , Bastianelli Gustavo , Chiostri Benjamin , Gutierrez Guillermo , Klinger Daniel Alberto , Vaccarino Guillermo
Published: November 2020

Objective:

Coronary complications may present during or after repair of congenital heart defects. We report coronary artery bypass grafting (CABG) by internal thoracic artery (ITA) grafts to either coronary artery in children with congenital anomalies.

Methods:

Four cases who underwent CABG with ITA grafts from March 2016 to March 2020 were retrospectively reviewed.

Results:

At the time of operation, patient’s ages and weight were 7 and 20 months old and 14 and 15 years old and 6.5, 10, 40, and 45 kg, respectively. Diagnosis were anomalous origin of the left coronary artery from the pulmonary artery with leftward lateral ostial origin (n = 1), neopulmonary annulus hypoplasia post arterial switch with contiguous right coronary artery (RCA) arising from the left facing sinus (n = 1), RCA stenosis after the Ross procedure (n = 1), and right coronary ostial obstruction after aortic valve replacement in truncus arteriosus (n = 1). Procedures included left ITA to left coronary ostium (n = 1), right ventricular outflow tract (RVOT) enlargement with pulmonary valve replacement with left ITA to RCA (n = 1), RVOT enlargement with pulmonary valve replacement with right ITA to RCA (n = 1), and aortic valve re-replacement, pulmonary valve replacement, and right ITA to RCA (n = 1). At last follow-up, all four patients were asymptomatic, with normal ventricular function, and all grafts were patent.

Conclusions:

The use of CABG in children is valuable alternative when dealing with complex coronary anatomy not suitable for classic repairs. In children, graft patency is required to be longer than 50 years; therefore, use of arterial grafts seems mandatory.
Long-Term Follow-Up of Pericardium for the Ventricular Component in Atrioventricular Septal Defect Repair
Authors: IJsselhof Rinske J. , Duchateau Saniyé D. R. , Schouten Rianne M. , Slieker Martijn G. , Hazekamp Mark G. , Schoof Paul H.
Published: November 2020

Background:

Despite the improved outcome in complete atrioventricular septal defect (AVSD) repair, reoperations for left atrioventricular valve (LAVV) dysfunction are common. The aim of this study was to evaluate the effect of fresh untreated autologous pericardium for ventricular septal defect (VSD) closure on atrioventricular valve function and compare the results with the use of treated bovine pericardial patch material.

Methods:

Clinical and echocardiographic data were collected of patients with complete AVSD with their VSD closed with either untreated autologous pericardial or treated bovine pericardial patch material between January 1, 1996, and December 31, 2003. Evaluation closed in September 2019.

Results:

A total of 77 patients were analyzed (untreated autologous pericardial VSD patch: 59 [77%], treated bovine pericardial VSD patch: 18 [23%]). Median age at surgery was 3.6 (interquartile range [IQR]: 2.7-4.5) months, and median weight was 4.5 (IQR: 3.9-5.1) kg. Trisomy 21 was present in 70 (91%) patients. Median follow-up time was 17.5 (IQR: 12.6-19.8) years. Death <30 days occurred in two (3%) patients. Reinterventions occurred in eight patients (early [within 30 days] in two, early and late in one, and late in five), all in the autologous pericardium group. Log-rank tests showed no significant difference in mortality ( P = .892), LAVV reinterventions ( P = .228), or LAVV regurgitation ( P = .770).

Conclusions:

In AVSD, the VSD can safely be closed with either untreated autologous pericardium or xeno-pericardium. We found no difference in LAVV regurgitation or the need for reoperation between the two patches.
Metabolic Alkalosis in the Pediatric Patient: Treatment Options in the Pediatric ICU or Pediatric Cardiothoracic ICU Setting
Authors: Tobias Joseph D.
Published: November 2020

Metabolic alkalosis is characterized by the primary elevation of the serum bicarbonate concentration with a normal or elevated partial pressure of carbon dioxide. Although there may be several potential etiologies in the critically ill patient in the pediatric or cardiothoracic intensive care unit, metabolic alkalosis most commonly results from diuretic therapy with chloride loss. In most cases, the etiology can be determined by a review of the patient’s history and medication record. Although generally innocuous with limited impact on physiologic function, metabolic alkalosis may impair central control of ventilation, especially when weaning from mechanical ventilation. The following manuscript presents the normal homeostatic mechanisms that control pH, reviews the etiology of metabolic alkalosis, and outlines the differential diagnosis. Options and alternatives for treatment including pharmacologic interventions are presented with a focus on these conditions as they pertain to the patient in the pediatric or cardiac intensive care unit.
Use of a Digital Monitoring Platform to Improve Outcomes in Infants With a Single Ventricle
Authors: Vergales Jeffrey , Peregoy Leslie , Zalewski Jodi , Plummer Sarah Tyler
Published: November 2020

Background:

Despite advances, infants with single ventricle heart disease continue to have high morbidity and mortality in the first year of life. Home monitoring programs (HMPs) have reduced mortality and have grown to use integrative digital platforms. The objective was to evaluate how implementation of a digital HMP platform affects nutritional outcomes in infants undergoing staged single ventricle palliation.

Methods:

We conducted a retrospective, multicenter, observational study of all infants who required a neonatal operation as part of staged single ventricle palliation between 2013 and 2018. Patients were excluded if less than 35 weeks’ gestation or underwent biventricular repair in the first year of life. Implementation of a digital monitoring platform that allows for secure monitoring of nasogastric feed advancement and oxygen saturation occurred in 2016, creating the two groups in a similar surgical era.

Results:

There were 38 patients who fell under a standard HMP compared to 31 utilizing the digital platform. There was no difference in baseline demographics, anatomy, or preoperative factors between the groups. Use of a digital platform was associated with reduced postoperative length of stay (30.1 vs 33.1 days, P = .04). More children in the digital platform monitoring group were able to achieve oral feeding at one year of age (90% vs 68%, P = .03). A total of 25% of infants went home with a nasogastric tube, all but one transitioning to full oral feeds.

Conclusions:

Use of a digital, fully electronic medical record (EMR)-integrated, comprehensive HMP was associated with shorter postoperative length of stay in neonates undergoing staged single ventricle palliation and allowed for higher rates of full oral feeding.
Prevalence of Complications Following Unifocalization and Pulmonary Artery Reconstruction Procedures
Authors: Mainwaring Richard D. , Patrick William L. , Dixit Mihir , Rao Akhil , Palmon Michal , Margetson Tristan , Lamberti John J. , Hanley Frank L.
Published: November 2020

Background:

Unifocalization and pulmonary artery reconstructions have been developed to treat complex disorders of pulmonary artery development. These procedures require extremely long periods of cardiopulmonary bypass (CPB) to facilitate surgical repair. The objective of this study was to document the prevalence of complications in patients undergoing unifocalization or pulmonary artery reconstructions associated with prolonged periods of CPB.

Methods:

This was a retrospective review of 100 consecutive patients who underwent unifocalization (n = 66) or pulmonary artery reconstructions (n = 34) with CPB times in excess of five hours. Thirty-eight of these operations were primary procedures, whereas 62 were reoperations.

Results:

The median age at surgery was 15 months, median duration of CPB was 473 minutes, median number of postoperative complications was 5, and the median length of hospital stay was 24 days. The most frequently encountered complications were low cardiac output (43%), open sternum (40%), reintubation (24%), arrhythmia (17%), and bronchoscopy (17%). There was a correlation between the total number of complications and overall length of hospital stay ( R 2 = 0.64). Major adverse cardiac events (MACE) occurred in 11 patients with one hospital mortality. Patients who experienced MACE had a median length of stay that was 35 days longer (56 vs 21 days) than patients who did not experience MACE.

Conclusions:

The data demonstrate that complications were relatively frequent in this cohort of patients and had a linear association with hospital length of stay. Major adverse cardiac events were encountered at a modest prevalence but had a profound impact on measures of outcome.
Exercise-Induced Abnormalities of Regional Myocardial Deformation in Anomalous Aortic Origin of the Right Coronary Artery
Authors: Binka Edem , Zhao Ni , Wood Scott , Zimmerman Stefan L. , Thompson W. Reid
Published: November 2020

Aims:

Congenital coronary artery anomalies are uncommon and may result in sudden death. Management of asymptomatic patients with anomalous aortic origin of the right coronary artery (AAORCA) remains controversial with a lack of evidence to guide decision-making. We hypothesized that patients with AAORCA may have exercise-inducible ischemia detectable as abnormalities in regional myocardial deformation on exercise stress echocardiography (ESE).

Methods:

We reviewed clinical data, computed tomography angiography, and treadmill ESE from 33 AAORCA patients (21 unoperated, 12 operated) and 11 controls. Regional wall motion on ESE was visually assessed. Doppler tissue imaging was done pre and post exercise to evaluate regional myocardial wall deformation. The post- to pre-exercise time to peak systolic strain corrected for heart rate ratio (TPScR) for the left ventricular inferior and anterior walls of AAORCA patients was compared to controls.

Results:

No regional wall motion abnormalities were noted. The TPScR of the inferior wall was higher in unoperated (0.96 ± 0.41) but not operated (0.84 ± 0.28) AAORCA patients compared to controls (0.76 ± 0.18, P = .03 vs .23, respectively). There was no significant difference in TPScR of the anterior wall between unoperated patients and controls ( P = .08).

Conclusion:

In some AAORCA patients undergoing ESE, TPScR of the left ventricular inferior wall is elevated, suggestive of ischemia induced by exercise in myocardium supplied by the right coronary artery. Further work is needed to understand the potential role of this finding in risk assessment.
Type B Aortic Dissection Complicating Stage 1 Norwood Procedure
Authors: Venardos Neil , Browne Lorna P. , Fujiwara Takashi , Mitchell Max B.
Published: November 2020

We present a rare case of iatrogenic type B aortic dissection due to ductal cannulation during stage 1 Norwood procedure.
The Congenital Tricuspid Valve Spectrum: From Ebstein to Dysplasia
Authors: Stephens Elizabeth H. , Dearani Joseph A. , Qureshi Muhammad Y. , Ammash Naser , Maleszewski Joseph J.
Published: November 2020

Ebstein anomaly has a breadth of presentations, including “typical” and “atypical,” and can be confused with congenital tricuspid dysplasia. We summarize how to differentiate within this spectrum of disease. Both typical and atypical Ebstein have an underlying failure of delamination, but atypical Ebstein does not have ≥8mm/m2 apical septal leaflet displacement. In congenital tricuspid dysplasia, delamination is normal, while the leaflets and subvalvar apparatus are abnormal. To summarize, the sine qua non feature of Ebstein anomaly, present in both typical and atypical, is the failure of delamination. These are distinct from congenital tricuspid valve dysplasia in which the pathology is in the leaflet itself.
Three-Dimensional Congenital Heart Models Created With Free Software and a Desktop Printer: Assessment of Accuracy, Technical Aspects, and Clinical Use
Authors: Perens Gregory , Chyu Justin , McHenry Kevin , Yoshida Takegawa , Finn J. Paul
Published: November 2020

Background:

Three-dimensional printing is increasingly recognized as a valuable tool for congenital heart disease (CHD) procedural planning and education. Cost and complexity currently limit the more widespread adoption of this technology. We sought to demonstrate the accuracy of 3D printed CHD models created from contrast-enhanced magnetic resonance imaging (MRI) and computed tomography (CT) scans using free software and an inexpensive desktop fused filament fabrication (FFF) printer.

Methods:

Solid segmentations of the intracardiac blood pool were created with the program ITK-SNAP. Using the computer program Meshmixer, the segmentation model was hollowed to create a 0.8 mm shell with the inner surface representing endocardium. Three-dimensional models were created on an FFF printer. Four arteries and a ventricular septal defect (VSD) were 3D printed and measured for accuracy. Five models were used to assess candidacy for biventricular surgical repair and one to guide an interventional catheterization.

Results:

All six patients underwent intervention planned with the 3D models. The computer model shell walls all achieved specifications within 0.05 mm of the designated 0.8 mm thickness and the original solid blood pool segmentation fit within the hollowed 3D model. The 3D printed arteries and VSD all measured accurately to within 0.5 mm of their source computer model.

Conclusion:

Accurate 3D printed models of complex, pediatric CHD may be created from volumetric MRI and CT studies using free online software and printed on an inexpensive desktop printer.
Correction to: EpCAM aptamer mediated cancer cell specific delivery of EpCAM siRNA using polymeric nanocomplex
Authors: Subramanian Nithya , Kanwar Jagat R. , Athalya Prasanna kumar , Janakiraman Narayanan , Khetan Vikas , Kanwar Rupinder K. , Eluchuri Sailaja , Krishnakumar Subramanian
Published: November 2020

An amendment to this paper has been published and can be accessed via the original article.
Association between triglyceride-glucose index and risk of incident diabetes: a secondary analysis based on a Chinese cohort study
Authors: Li Xiaoli , Li Guilong , Cheng Tiantian , Liu Jing , Song Guangyao , Ma Huijuan
Published: November 2020

Background

Recent studies have suggested the triglyceride-glucose index (TyG index) may serve as a suitable substitute for insulin resistance. However, evidence for the relationship between TyG index and risk of diabetes remains limited. This study sought to explore the association of baseline TyG index with risk of developing diabetes in Chinese adults.

Methods

This retrospective cohort study was conducted using data from the health screening program in China. A total of 201,298 non-diabetic individuals were included. TyG index was calculated as Ln [fasting plasma glucose (mg/dL) × fasting triglyceride level (mg/dL) / 2]. Diabetes was defined as fasting plasma glucose ≥126 mg/dL and/or self-reported diabetes. Cox proportion-hazard model was employed to evaluate the independent impact of baseline TyG index on future diabetes risk. Sensitivity and subgroup analyses were implemented to verify the reliability of results. Notably, data were downloaded from the DATADRYAD website, and used only for secondary analyses.

Results

During an average follow-up of 3.12 years, among 201,298 individuals aged ≥20 years, 3389 subjects developed diabetes. After adjusting for potential confounders, elevated TyG index were independently correlated with greater risk of incident diabetes (hazard ratio (HR), 3.34; 95% confidence interval (CI), 3.11–3.60). Compared with the lowest quartile (Q1), increasing TyG index (Q2, Q3, and Q4) was related to increased HR estimates of incident diabetes [HR (95% CI), 1.83 (1.49–2.26); 3.29 (2.70–4.01), and 6.26 (5.15–7.60), respectively]. Moreover, a nonlinear relationship was observed between TyG index and risk of diabetes and the slope of the curve increased accompanying the rise of TyG index. Subgroup analysis revealed the positive association was stronger among subjects with age < 40 years, body mass index ≥18.5 kg/m2 and < 24 kg/m2, or systolic blood pressure < 140 mmHg, or in females.

Conclusions

Elevated TyG index is independently correlated with increased risk of incident diabetes in Chinese adults, indicating it may represent a reliable predictor of diabetes in high-risk populations.
Evaluation of lipid ratios and triglyceride-glucose index as risk markers of insulin resistance in Iranian polycystic ovary syndrome women
Authors: Kheirollahi Asma , Teimouri Maryam , Karimi Mehrdad , Vatannejad Akram , Moradi Nariman , Borumandnia Nasrin , Sadeghi Asie
Published: November 2020

Background

Insulin resistance has a vital role in the pathophysiology of polycystic ovary syndrome (PCOS). Previous investigations have shown that some lipid ratios could be a simple clinical indicator of insulin resistance (IR) in some disorders and ethnicities. The present study was conducted to evaluate the correlation between triglyceride to HDL-cholesterol (TG/HDL-C), total cholesterol to HDL-cholesterol (TC/HDL-C), as well as fasting triglyceride-glucose (TyG) indices with IR (as measured by homeostasis model assessment of IR (HOMA-IR), quantitative insulin sensitivity check index (QUICKI) and fasting glucose to insulin ratio (FGIR)) among the Iranian women diagnosed with PCOS.

Methods

In the current study, a total of 305 women with PCOS were evaluated. TG/HDL-C, TC/HDL-C, and TyG indices were calculated. Fasting insulin level was measured using ELISA technique. IR was defined as a HOMA-IR value of ≥2.63, FG-IR value of < 8.25, and QUICKI value of < 0.33.

Results

The insulin-resistant (IR) and insulin-sensitive (IS) groups, established by the HOMA-IR, FG-IR, and QUICKI values were different in terms of TG/HDL-C, TC/HDL-C, and TyG indices. These indices were associated with IR even after adjusting for age and BMI. ROC curve analyses showed that TyG, TG/HDL-C, and TC/HDL-C strongly predicted HOMA-IR with area under the curve (AUC) of 0.639, 0.619, and 0.623, respectively (P < 0.05). Further, TC/HDL-C was a good predictor of FG-IR with AUC of 0.614 (P = 0.04).

Conclusion

TyG, TG/HDL-C, and TC/HDL-C indices might be good indicators of IR among Iranian women diagnosed with PCOS.
Chemokine CXCL13 acts via CXCR5-ERK signaling in hippocampus to induce perioperative neurocognitive disorders in surgically treated mice
Authors: Shen Yanan , Zhang Yuan , Chen Lihai , Du Jiayue , Bao Hongguang , Xing Yan , Cai Mengmeng , Si Yanna
Published: November 2020

Background

Perioperative neurocognitive disorders (PNDs) occur frequently after surgery and worsen patient outcome. How C-X-C motif chemokine (CXCL) 13 and its sole receptor CXCR5 contribute to PNDs remains poorly understood.

Methods

A PND model was created in adult male C57BL/6J and CXCR5−/− mice by exploratory laparotomy. Mice were pretreated via intracerebroventricular injection with recombinant CXCL13, short hairpin RNA against CXCL13 or a scrambled control RNA, or ERK inhibitor PD98059. Then surgery was performed to induce PNDs, and animals were assessed in the Barnes maze trial followed by a fear-conditioning test. Expression of CXCL13, CXCR5, and ERK in hippocampus was examined using Western blot, quantitative PCR, and immunohistochemistry. Levels of interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) in hippocampus were assessed by Western blot.

Results

Surgery impaired learning and memory, and it increased expression of CXCL13 and CXCR5 in the hippocampus. CXCL13 knockdown partially reversed the effects of surgery on CXCR5 and cognitive dysfunction. CXCR5 knockout led to similar cognitive outcomes as CXCL13 knockdown, and it repressed surgery-induced activation of ERK and production of IL-1β and TNF-α in hippocampus. Recombinant CXCL13 induced cognitive deficits and increased the expression of phospho-ERK as well as IL-1β and TNF-α in hippocampus of wild-type mice, but not CXCR5−/− mice. PD98059 partially blocked CXCL13-induced cognitive dysfunction as well as production of IL-1β and TNF-α.

Conclusions

CXCL13-induced activation of CXCR5 may contribute to PNDs by triggering ERK-mediated production of pro-inflammatory cytokines in hippocampus.
Investigation of different electrochemical cleaning methods on contaminated healing abutments in vitro: an approach for metal surface decontamination
Authors: Kyaw Thiha Tin , Hanawa Takao , Kasugai Shohei
Published: November 2020

Background

To evaluate the effects of electrolysis on cleaning the contaminated healing abutment surface and to detect the optimal condition for cleaning the contaminated healing abutment.

Methods

Ninety healing abutments removed from patients were placed in 1% sodium dodecyl sulfate solution and randomly divided for electrolysis with 7.5% sodium bicarbonate in the following three different apparatuses (N = 30): two stainless steel electrodes (group I), a copper electrode and a carbon electrode (group II), and two carbon electrodes (group III). The samples were placed on cathode or anode with different electric current (0.5, 1, and 1.5 A) under constant 10 V for 5 min. Electrolyte pH before and after electrolysis were measured. Then, the samples were stained with phloxine B and photographed. The proportion of stained areas was calculated. The surface was examined with a scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS).

Results

Electrolyte pH decreased after electrolysis at 1 A and 1.5 A in group I and II. Applying cathode at 1 A in group III, the amount of residual contamination was the lowest in all the conditions examined in the present study. SEM images revealed that applying cathode at 1.5 A in group I induced a rough surface from the smooth surface before the treatment. EDS analysis confirmed that the surfaces treated on cathode at 1 A in group III revealed no signs of organic contamination.

Conclusion

Electrolysis of using carbon as electrodes, placing the contaminated healing abutments on cathode, and applying the electric current of 1 A at constant 10 V in 7.5% sodium bicarbonate could completely remove organic contaminants from the surfaces. This optimized electrochemical cleaning method seems to be well worth investigation for the clinical management of peri-implant infections.
The comparison between curcumin and propolis against sepsis-induced oxidative stress, inflammation, and apoptosis in kidney of adult male rat
Authors: Abd-Elrazek Areeg , Mahmoud Sahar , Abd ElMoneim Ahmed
Published: November 2020

Background

Propolis is a honeybee product displaying an anti-inflammatory, antimicrobial, and antioxidant effect on several tested animal models. Curcumin a polyphenol extracted from turmeric that gained interest as a potentially safe and inexpensive treatment for kidney diseases.

The present study aimed to compare the protective effects of curcumin and propolis on endotoxemia-induced renal dysfunction.

Results

Sepsis induction caused a marked decline in renal GSH, GPx, and GR, as well as antioxidant enzyme activities; CAT and SOD. Elevation in LPO, NO, IL-1β, and PGE2 contents were observed as well. A marked induction in Bax contents, Bax\Bcl2 ratio, accompanied by activation of NF-kB in the kidney of sepsis-induced rats was reported. However, Prop pretreatment of endotoxemic rats was effective in controlling the depletion of renal GSH content and its correlated enzymes; Cur was more potent in maintaining the renal CAT and SOD contents, as well as, dimensioning LPO content. Despite the renal inflammatory marker IL-1β, PGE2, NO contents, Bax\Bcl2 ratio, and NF-kB activation were greatly reduced by both curcumin and propolis, only Cur pretreatment attenuated NF-kB activation in kidney tissue of septic rat.

Conclusion

Though pretreatment of either Cur or Prop to septic rats protected their kidneys against oxidation, inflammation, and apoptosis status, Cur pretreatment was superior in protecting rats’ kidney after sepsis induction.
Overview of Extensively Employed Polymeric Carriers in Solid Dispersion Technology
Authors: Nair Athira R. , Lakshman Yarlagadda Dani , Anand Vullendula Sai Krishna , Sree K. S. Navya , Bhat Krishnamurthy , Dengale Swapnil J.
Published: November 2020

Solid dispersion is the preferred technology to prepare efficacious forms of BCS class-II/IV APIs. To prepare solid dispersions, there exist a wide variety of polymeric carriers with interesting physicochemical and thermochemical characteristics available at the disposal of a formulation scientist. Since the advent of the solid dispersion technology in the early 1960s, there have been more than 5000 scientific papers published in the subject area. This review discusses the polymeric carrier properties of most extensively used polymers PVP, Copovidone, PEG, HPMC, HPMCAS, and Soluplus® in the solid dispersion technology. The literature trends about preparation techniques, dissolution, and stability improvement are analyzed from the Scopus® database to enable a formulator to make an informed choice of polymeric carrier. The stability and extent of dissolution improvement are largely dependent upon the type of polymeric carrier employed to formulate solid dispersions. With the increasing acceptance of transfer dissolution setup in the research community, it is required to evaluate the crystallization/precipitation inhibition potential of polymers under dynamic pH shift conditions. Further, there is a need to develop a regulatory framework which provides definition and complete classification along with necessarily recommended studies to characterize and evaluate solid dispersions.
Stretch-excitation correlation in the toad heart
Authors: Vityazev Vladimir A. , Azarov Jan E.
Published: November 2020

The activation sequence of the ventricular myocardium in ectotherms is a matter of debate. We studied the correlation between the ventricular activation sequence and the pattern of local stretches in 13 toads (Bufo bufo). Epicardial potential mapping was done with 56-lead sock array. Activation times were determined as dV/dt min in each lead. Initial epicardial foci of activation were found on the left side of the ventricular base, whereas regions on the apex and the right side of the base demonstrated late activation. Video recordings (50 frames/s) showed that a median presystolic stretch in left-side ventricular regions were greater than in right-side regions [4.70 (interquartile range 3.25-8.85)% vs 1.45 (interquartile range 0.38-3.05)%, p=0.028, respectively]. Intracardiac bolus injection elicited ventricular activation with a similar sequence and duration. Thus, ventricular areas of earliest activation were associated with greater presystolic stretch, implying the existence of stretch-excitation relationship in ectotherms’ hearts.
Synergetic effects of immune challenge and stress depress cortisol, inflammatory response and antioxidant activity in fish-eating Myotis
Authors: Hernández-Arciga Ulalume , Herrera M. L. Gerardo , Königsberg Mina , Valdez Ricardo A. , Flores-Martínez José Juan , Romano Marta C.
Published: November 2020

One of the most common tools in conservation physiology is the assessment of environmental stress via glucocorticoid measurement. However, little is known of its relationship with other stress related biomarkers, and how the incidence of an immune challenge during a long-term stress could affect individuals overall stress response. We investigated here the relationship between basal and post-acute stress fecal cortisol metabolite (FC) with different antioxidant enzymes, oxidative damage, and immune parameters in the fish-eating Myotis (Myotis vivesi). We found that in both basal and post-stress conditions, FC was highly related to a number of antioxidant enzymes and immune parameters, but no to oxidative damage. We also assessed changes of FC through the seasons. Basal FC samples and stress reactivity after a short-duration stress, displayed similar levels during summer, autumn and early winter, albeit lower concentrations in late winter. Stress reactivity after long-duration stress was greater in summer and early winter. Finally, we tested the effect of a simultaneous exposition to a long-strong-stress stimulus with an immune response stimulation by administrating adrenocorticotropic hormone (ACTH) and phytohemaglutanin (PHA) after 42 h. Results showed that when both stimulus were administrated, FC concentrations, inflammation and some antioxidant activity were lowered in comparison to the control and individual administration of the challenges. Our findings support the idea that animals maintain constant basal GC levels when living in challenging environments, but response to acute stress differs seasonally and immune defense mechanisms and stress response might be compromised when confronted with multiple challenges.
A direct excitatory action of lactate ions in the central respiratory network
Authors: Burton Michael T. , Santin Joseph M.
Published: November 2020

Chemoreceptors that detect O2 and CO2/pH regulate ventilation. However, recent work shows that lactate ions activate arterial chemoreceptors independent of pH to stimulate breathing. Although lactate rises in the central nervous system (CNS) during metabolic challenges, the ability for lactate ions to enhance ventilation by directly targeting the central respiratory network remains unclear. To address this possibility, we isolated the amphibian brainstem-spinal cord and found that small increases in CNS lactate stimulate motor output that causes breathing. In addition, lactate potentiated the excitatory postsynaptic strength of respiratory motor neurons, thereby coupling central lactate to the excitatory drive of neurons that trigger muscle contraction. Lactate did not affect motor output through pH or pyruvate metabolism, arguing for sensitivity to lactate anions per se. In sum, these results introduce a mechanism whereby lactate ions in the CNS match respiratory motor output to metabolic demands.
Seismic sensitivity and bone conduction mechanisms enable extratympanic hearing in salamanders
Authors: Capshaw G. , Soares D. , Christensen-Dalsgaard J. , Carr C. E.
Published: November 2020

The tympanic middle ear is an adaptive sensory novelty that evolved multiple times in all of the major terrestrial tetrapod groups to overcome the impedance mismatch generated when aerial sound encounters the air-skin boundary. Many extant tetrapod species have lost their tympanic middle ears, yet they retain the ability to detect airborne sound. In the absence of a functional tympanic ear, extratympanic hearing may occur via the resonant qualities of air-filled body cavities, sensitivity to seismic vibration, and/or bone conduction pathways to transmit sound from the environment to the ear. We used auditory brainstem response recording and laser vibrometry to assess the contributions of these extratympanic pathways for airborne sound in atympanic salamanders. We measured auditory sensitivity thresholds in eight species and observed sensitivity to low frequency sound and vibration from 0.05-1.2 kHz and 0.02-1.2 kHz, respectively. We determined that sensitivity to airborne sound is not facilitated by the vibrational responsiveness of the lungs or mouth cavity. We further observed that, although seismic sensitivity likely contributes to sound detection under naturalistic scenarios, airborne sound stimuli presented under experimental conditions did not produce vibrations detectable to the salamander ear. Instead, threshold-level sound pressure is sufficient to generate translational movements in the salamander head, and these sound-induced head vibrations are detectable by the acoustic sensors of the inner ear. This extratympanic hearing mechanism mediates low frequency sensitivity in vertebrate ears that are unspecialized for the detection of aerial sound pressure, and may represent a common mechanism for terrestrial hearing across atympanic tetrapods.
High-lipid prey reduce juvenile survivorship and delay egg-laying in a small linyphiid spider Hylyphantes graminicola
Authors: Wen Lelei , Jiao Xiaoguo , Liu Fengxiang , Zhang Shichang , Li Daiqin
Published: November 2020

Prey proteins and lipids greatly impact predator life-history traits. However, life-history plasticity offers predators the opportunity to tune the life-history traits in response to the limited macronutrients to allocate among traits. A fast-growing predator species with a strict maturation time may be prone to nutritionally imbalanced prey. Here we tested this hypothesis by examining the effect of the protein-to-lipid ratio in prey on a small sheetweb spider, Hylyphantes graminicola, with a short life-span, using adult Drosophila melanogaster as the prey. By manipulating the macronutrient content of prey to generate three prey types with different protein-to-lipid ratios (i.e., high, intermediate and low), we demonstrated that the majority of the spiders that consumed only these flies could reach full maturity. However, juvenile spiders that consumed high-lipid (low protein-to-lipid ratio) flies had a higher rate of mortality than those consuming medium-protein and high-protein flies. The prey protein-to-lipid ratio had no significant effects on the developmental duration and size at maturity. Although the prey protein-to-lipid ratio had no significant influence on mating behaviour and female fecundity, females reared on high-lipid flies exhibited a significant delay in oviposition compared to those reared on high-protein flies. We conclude that high-lipid prey has negative effects on the survival and reproductive function of H. graminicola. Our study thus provides clear evidence that low plasticity with fast development to a certain size means high nutritional requirement for protein at a cost of lower survival and prolonged time to egg laying when prey have low protein-to-lipid content in H. graminicola.
Application of concepts of concordance and health beliefs to individuals with pressure ulcers
Authors: James Amie , Holloway Samantha
Published: November 2020

The management of individuals with chronic health conditions, including patients with non-healing or complex wounds, is a challenge for healthcare systems. Current initiatives within the UK encourage patients to take an active role in managing their own health. To facilitate this, it is essential that healthcare professionals understand how health beliefs can influence health behaviours. This article examines theoretical frameworks, such as the health belief model and the multidimensional locus of control scale, and discusses the key features of concordance. Concepts of concordance, including shared decision making and patient-centred practice, are applied to research involving individuals with pressure ulcers. Consideration is also given to psychosocial factors such as cultural differences, quality of life and coping mechanisms.
Exploring the learning climate in anaesthesiology training hospitals in Ireland
Authors: Walshe Criona M , Flaherty Gerard
Published: November 2020

Background

Learning climate is defined as the learners' perception of their environment. There is growing evidence that learning climate is a major determinant of trainee behaviour. This mixed methods study evaluated the learning climate in anaesthesiology training hospitals in Ireland.

Methods

Through sequential explanatory strategy, learning climate was measured using a validated 40-item questionnaire, which was completed by 118 anaesthesiology trainees from eight training hospitals in Ireland. This was followed by two focus group interviews with 16 participants. Qualitative interpretations were derived using framework analysis.

Results

The mean learning climate score was from the questionnaire 116 (+/−15.7) out of 160. The highest level of satisfaction recorded was for the perception of atmosphere (scoring 76% of the maximum score), while learning opportunities ranked lowest (67% of the maximum score). Three key themes emerged from the focus groups: lack of resources, the transient nature of the job and the sense of a gap between consultants and trainees.

Conclusions

Overall there was an acceptable learning climate in training hospitals in Ireland, but satisfaction levels may vary and lack of learning opportunities appears to be a significant issue for trainees.
The financial cost of sharps injuries
Authors: Hambridge Kevin , Endacott Ruth , Nichols Andrew
Published: November 2020

Research into sharps injuries has focused on the volume of incidents and, to a smaller degree, the psychological impact of those incidents. This narrative literature review instead explored the financial cost of sharps injuries as reported by both UK and international studies. This involved a search of 13 electronic databases and grey literature, with no set date limits, in June 2019. Both direct and indirect costs of sharps injuries were identified, indicating the high financial costs of such incidents to healthcare systems across many different countries each year. Further research is urgently needed to address the continued prevalence of sharps injuries and to reduce the associated costs.
The ‘just culture’: why it is not just, and how it could be
Authors: Stretton Paul
Published: November 2020

Healthcare organisations have struggled to move from a culture of blame to a ‘just culture’, despite this being stated as a goal for several years. As a result of this cultural inertia, the original principles of a just culture require critical examination. A just culture is still seen primarily as a linear mechanism to apportion liability. Within our complex healthcare organisations, this approach is inadequate. This article proposes a revised approach to creating a just culture, which enables learning from all events, irrespective of outcome. There should be a focus on learning, rather than liability, with a presumption of good intention until proven otherwise. This more compassionate and respectful approach can help to move healthcare organisations towards a just culture and create an atmosphere of trust.
Redeploying junior doctors during a pandemic: reflections of a rota management team
Authors: Whitby Thomas M , Ferguson Sarah , Halfhide Clare P
Published: November 2020

Medical on-call rotas are found in every hospital, but what do you do when a pandemic occurs? This article describes the process of escalation, redeployment, de-escalation and the lessons learnt by a rota management team in a busy regional paediatric hospital.
No more nursing homes? Changes in consumer preferences for long-term care facilities following COVID-19
Authors: Schultz Amber F , Yu Jia
Published: November 2020

Since the first COVID-19 case was discovered in December 2019, over 12.1 million cases have been reported in more than 188 countries and territories. In the USA, the Centers for Disease Control and Prevention has confirmed almost 3.05 million COVID-19 cases, with more than 132 000 deaths. The COVID-19 pandemic has had a particularly dramatic impact on the elderly and those with chronic underlying medical disorders. Before the second outbreak in July, long-term care facilities were the most severely affected in terms of case numbers, especially nursing homes. This article provides information and insight into the potential changes in consumer preferences toward long-term care facility selection and the possible structural change of the long-term care industry in three aspects; structure, conduct and performance.
Influenza vaccination uptake: past lessons and future implications
Authors: Winter George
Published: November 2020

The COVID-19 pandemic has made influenza vaccination for vulnerable populations more important than ever, but uptake rates from previous years are a cause for concern. George Winter discusses the importance of learning from past vaccination campaigns, both for this influenza season and for any future COVID-19 vaccine.
For everything there was a season: phenological shifts within the flora of the Tetons
Authors: Bloom Trevor , Riginos Corinna
Published: November 2020

Around the world, phenology — the timing of ecological events — is shifting as the climate warms. This can lead to a variety of consequences for individual species and entire ecological communities, most notably when asynchronies develop between plants and animals that depend upon each other (e.g. nectar-consuming pollinators). Grand Teton National Park biologists have identified this topic (“effect of earlier plant flowering on pollinators and wildlife”) as one of their priority research needs. We have gathered, digitized, and quality-controlled phenological observations of first flowering dates collected by Frank Craighead, Jr. in the 1970s, before significant warming occurred. First flowering date for 87% of a 72-species data set correlates significantly with spring temperatures in the 1970s, suggesting that these plants should now be flowering earlier and will continue to flower earlier in the future. This year we began standardized phenological observations of these 72 species in the same location and initiated a citizen science program. Our proposed next steps are to: (1) gather and analyze further historical records of plant phenology; (2) conduct 3-5 additional years of contemporary observations; (3) link plant phenological changes with potential cascading impacts on pollinators and foragers; (4) model phenology under future climate change scenarios; and (5) implement a long-term citizen science program in the Tetons.

 

Featured photo by Shawna Wolf, taken from the AMK Ranch photo collection.
Paleoseismic study of the Northern Teton Fault, Wyoming
Authors: Thackray Glenn D. , Zellman Mark
Published: November 2020

We investigated the earthquake history of the northern portion of the Teton fault by excavating two trenches across a fault scarp near the eastern shore of Jackson Lake, near Steamboat Mountain. We identified the primary stratigraphy of the trenches, logged the trenches in detail, and collected samples for dating analyses. The trenches exposed faulted glacial sediments and overlying hill slope colluvium and alluvial sediments. Interpretation of the trench stratigraphy is ongoing. Samples are currently being analyzed using radiocarbon and luminescence dating techniques to determine the ages of the sediments and constrain the timing of fault rupture. We hosted several visitors at the trench site, including professionals and students, and introduced two interns to the process of fault trenching and documentation.

 

Featured photo from Figure 3 in report.
Beaver and state transition in Yellowstone
Authors: Brooks Marjorie L.
Published: November 2020

Extirpation of wolves from the Greater Yellowstone Ecosystem (GYE) in the 1920shypothetically triggered a behaviorally-mediated trophic cascade in which elk (Cervus elaphus), released from the fear of wolf (Canis lupus) predation, over-browsed riparian zones. Eventually, vast areas of meadow-wetland complexes transitioned to grass-lodgepole systems. The importance of beaver (Castor canadensis) in wetland losses has received less attention. Beaver abandoned most of the GYE by the 1950s, possibly due to resource limitations. Researchers from Colorado State University established an experimental system for Long Term Environmental Research in Biology (LTREB) along several streams in the Lamar Valley of Yellowstone sixteen years ago. To evaluate effects of hydrologic changes and elk browsing on productivity of willows (Salix spp.) and state transition, they built small experimental dams with browsing exclosures. In 2015, beaver began recolonizing the region. I am investigating how their biologic as well as hydrologic impacts affect the underlying mechanisms of state transition: nutrient cycling, productivity, and stream respiration. I posit that beaver are keystone species, meaning that the sustained recovery of wetland-meadow complexes is unlikely without the higher levels of riparian productivity triggered by the biological influence of beaver.

 

Featured photo by Ben Amaral on Unsplash. https://unsplash.com/photos/rohY54N6auU
Spatio-temporal ecological and evolutionary dynamics in natural butterfly populations
Authors: Gompert Zachariah , Lucas Lauren
Published: November 2020

Long term studies of wild populations indicate that natural selection can cause rapid and dramatic changes in traits, with spatial and temporal variation in the strength of selection a critical driver of genetic variation in natural populations. In 2012, we began a long term study of genome-wide molecular evolution in populations of the butterfly Lycaeides ideas in the Greater Yellowstone Area (GYA). We aimed to quantify the role of environment-dependent selection on evolution in these populations. Building on previous work, in 2017 we collected new samples, incorporated distance sampling, and surveyed the insect community at each site. We also defined the habitat boundary at anew, eleventh site. Our preliminary analyses suggest that both genetic drift and selection are important drivers in this system.

 

Featured photo from Figure 1 in report.
Are we overlooking the eco-geomorphic importance of wood in braided rivers?: A case study in Grand Teton National Park
Authors: Kasprak Alan , Mueller Erich , Sankey Joel , Wheaton Joseph M.
Published: November 2020

A decades-long body of research has hypothesized a fundamental incompatibility between braided rivers, which form due to a lack of bank cohesion and a highly-mobile channel bed, with vegetation, which stabilizes channel surfaces and hinders sediment mobilization. At the same time, many researchers have observed high densities of wood, occurring either as large jams or dense stands of mature trees, along the braid plain of multi-thread rivers worldwide. Here we seek to reconcile the perceived incompatibility of wood and braided rivers with the high densities of vegetation found along these streams using two multi-thread, gravel-bed rivers in Grand Teton National Park. In August of 2017, we completed topographic surveys along ~500 m reaches of Pacific and Pilgrim Creeks, tributaries to the Snake River in Jackson Hole. We seek to compare digital elevation models generated from these surveys with 2014 elevation data collected via airborne lidar to determine whether in-channel wood drives increases in bar density, depth variability, and in-channel habitat suitability for native salmonids. While the majority of our efforts following the August 2017 field campaign have been focused on lidar data processing and cleaning, our initial results indicate that wood is a dominant driver of bar formation in both Pilgrim and Pacific Creek, and may be the dominant driver of depth variability (e.g., pool scour) in gravel-bed braided streams in Grand Teton National Park.

 

Featured photo by Grand Teton on Flickr. https://flic.kr/p/MyszYZ