bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chronic Opioid Use and Central Sleep Apnea, Where Are We Now and Where To Go? A State of the Art Review
Authors: Wang David , Yee Brendon J. , Grunstein Ronald R. , Chung Frances 
Published: April 2021

Opioids are commonly used for pain management, perioperative procedures, and addiction treatment. There is a current opioid epidemic in North America that is paralleled by a marked increase in related deaths. Since 2000, chronic opioid users have been recognized to have significant central sleep apnea (CSA). After heart failure–related Cheyne-Stokes breathing (CSB), opioid-induced CSA is now the second most commonly seen CSA. It occurs in around 24% of chronic opioid users, typically after opioids have been used for more than 2 months, and usually corresponds in magnitude to opioid dose/plasma concentration. Opioid-induced CSA events often mix with episodes of ataxic breathing.
The pathophysiology of opioid-induced CSA is based on dysfunction in respiratory rhythm generation and ventilatory chemoreflexes. Opioids have a paradoxical effect on different brain regions, which result in irregular respiratory rhythm. Regarding ventilatory chemoreflexes, chronic opioid use induces hypoxia that appears to stimulate an augmented hypoxic ventilatory response (high loop gain) and cause a narrow CO2 reserve, a combination that promotes respiratory instability.
To date, no direct evidence has shown any major clinical consequence from CSA in chronic opioid users. A line of evidence suggested increased morbidity and mortality in overall chronic opioid users. CSA in chronic opioid users is likely to be a compensatory mechanism to avoid opioid injury and is potentially beneficial. The current treatments of CSA in chronic opioid users mainly focus on continuous positive airway pressure (CPAP) and adaptive servo-ventilation (ASV) or adding oxygen. ASV is more effective in reducing CSA events than CPAP. However, a recent ASV trial suggested an increased all-cause and cardiovascular mortality with the removal of CSA/CSB in cardiac failure patients. A major reason could be counteracting of a compensatory mechanism. No similar trial has been conducted for chronic opioid-related CSA. Future studies should focus on (1) investigating the phenotypes and genotypes of opioid-induced CSA that may have different clinical outcomes; (2) determining if CSA in chronic opioid users is beneficial or detrimental; and (3) assessing clinical consequences on different treatment options on opioid-induced CSA.
Propofol for Induction and Maintenance of Anesthesia in Patients With Brugada Syndrome: A Single-Center, 25-Year, Retrospective Cohort Analysis
Authors: Flamée Panagiotis , Viaene Kea , Tosi Maurizio , Nogueira Carvalho Hugo , de Asmundis Carlo , Forget Patrice , Poelaert Jan 
Published: April 2021

BACKGROUND:
Propofol administration in patients with Brugada syndrome (BrS) is still a matter of debate. Despite lacking evidence for its feared arrhythmogenicity, up to date, expert cardiologists recommend avoiding propofol. The main aim of this study is to assess the occurrence of malignant arrhythmias or defibrillations in patients with BrS, during and 30 days after propofol administration. The secondary aim is to investigate the occurrence of adverse events during propofol administration and hospitalization, as the 30-day readmission and 30-day mortality rate.

METHODS:
We performed a retrospective cohort study on patients with BrS who received propofol anytime from January 1, 1996 to September 30, 2020. Anesthesia was induced by propofol in both groups. In the total intravenous anesthesia (TIVA) group, anesthesia was maintained by propofol, while in the BOLUS group, volatile anesthesia was provided. The individual anesthetic charts and the full electronic medical records up to 30 postprocedural days were scrutinized.

RESULTS:
One hundred thirty-five BrS patients who underwent a total of 304 procedures were analyzed. The TIVA group included 27 patients for 33 procedures, and the BOLUS group included 108 patients for 271 procedures. In the TIVA group, the median time of propofol infusion was 60 minutes (interquartile range [IQR] = 30–180). The estimated plasma or effect-site concentration ranged between 1.0 and 6.0 µg·mL−
1 for target-controlled infusion (TCI). The infusion rate for manually driven TIVA varied between 0.8 and 10.0 mg·kg−
1·h−
1. In the BOLUS group, the mean propofol dose per kilogram total body weight was 2.4 ± 0.9 mg·kg−
1. No malignant arrhythmias or defibrillations were registered in both groups. The estimated 95% confidence interval (CI) of the risk for malignant arrhythmias in the BOLUS and TIVA groups was 0-0.011 and 0-0.091, respectively.

CONCLUSIONS:
The analysis of 304 anesthetic procedures in BrS patients, who received propofol, either as a TIVA or as a bolus during induction of volatile-based anesthesia, revealed no evidence of malignant arrhythmias or defibrillations. The present data do not support an increased risk with propofol-based TIVA compared to propofol-induced volatile anesthesia. Prospective studies are needed to investigate the electrophysiologic effects of propofol in BrS patents.
Local Anesthetics Inhibit Transient Receptor Potential Vanilloid Subtype 3 Channel Function in Xenopus Oocytes
Authors: Horishita Reiko , Ogata Yuichi , Fukui Ryo , Yamazaki Ryo , Moriwaki Kuniaki , Ueno Susumu , Yanagihara Nobuyuki , Uezono Yasuhito , Yokoyama Yuka , Minami Kouichiro , Horishita Takafumi 
Published: April 2021

BACKGROUND:
The transient receptor potential vanilloid subtype 3 (TRPV3) channel is activated by innocuous temperature and several chemical stimuli. It is proposed to be involved in pathological pain development and is therefore considered a potential target for treating pain. Local anesthetics have been used for patients with both acute and chronic pain. Although blockage of the voltage-gated sodium channel is the primary mechanism by which local anesthetics exert their effects, they cannot be explained by this mechanism alone, especially in pathologic states such as chronic pain. Indeed, the effects of local anesthetics on multiple targets involved in the pain pathway have been reported. It has also been suggested that modulating the function of transient receptor potential (TRP) channels (eg, TRPV1 and transient receptor potential ankyrin 1 [TRPA1]) is one of the mechanisms of action of local anesthetics. However, the effects of local anesthetics on TRPV3 have not been reported.

METHODS:
We expressed TRPV3 in Xenopus oocytes and investigated the effects of local anesthetics on 2-aminoethoxydiphenyl borate (2APB)–induced currents using 2-electrode voltage-clamp techniques.

RESULTS:
Clinically used local anesthetics inhibited the 2APB-activated currents from the TRPV3 channel in a concentration-dependent manner at pharmacologically relevant concentrations with half maximal inhibitory concentration (IC50) values of 2.5 (lidocaine), 1.4 (mepivacaine), 0.28 (ropivacaine), and 0.17 (bupivacaine) mmol/L, respectively. Conversely, these local anesthetics also directly induced currents at higher concentrations, although these currents were quite small compared to the 2APB-induced currents. We found that the inhibition of TRPV3 by lidocaine is noncompetitive and independent of intracellular signaling cascades. 2APB-induced TRPV3 currents were reduced by extracellular N-(2,6-dimethylphenylcarbamoylmethyl) triethylammonium bromide (QX-314) but not by intracellular QX-314 nor benzocaine. Moreover, lidocaine showed a use-dependent block in TRPV3 inhibition. Finally, QX-314 appeared to slightly permeate the activated TRPV3 channel pore based on examination of oocytes coexpressing TRPV3 and a sodium channel. These results suggest that local anesthetics could inhibit TRPV3 channel function by extracellular interactions of their charged forms with the channel pore.

CONCLUSIONS:
Local anesthetics inhibited TRPV3 2APB-induced currents at pharmacologically relevant concentrations when TRPV3 was expressed in Xenopus oocytes. These effects seem to occur via an extracellular interaction between the charged form of the anesthetic with the TRPV3 channel pore. These results help to elucidate the mechanisms of action of local anesthetics.
Measuring Marriage and Cohabitation: Assessing Same-Sex Relationship Status in the Current Population Survey
Authors: Manning Wendy D. , Payne Krista K. 
Published: April 2021

Abstract
Since June 26, 2015, marriages to same-sex couples have been legally recognized across every state in the United States, bringing new challenges to measuring relationship status in surveys. Starting in 2015 for select households and in 2017 for all households, the Current Population Survey (CPS) used a new household roster that directly identified same-sex and different-sex cohabiting and married couples. We gauge how the estimates and characteristics of same-sex couples vary according to old and new roster categories using the 2015/2016 and 2017/2018 CPS. Employing the new roster, we distinguish the sociodemographic characteristics of married and cohabiting same-sex couples. These findings have implications for the measurement of same-sex couples and our understanding of marriage among sexual minorities.
Unprofessional
Authors: Carpenter Bennett , Goldblatt Laura , Hanson Lenora 
Published: April 2021

AbstractThis article analyzes the case of Avital Ronell, Amy Hungerford's response to striking Yale graduate students, and higher education funding to argue that such instances illustrate the precise features of rampant professionalization—its pressures, demands, and imperatives—in the midst of the radical transformation of the material conditions that first produced its practices. Despite the increasingly limited ability for faculty to determine how their fields intersect with and are conditioned by forces beyond the confines of their carefully delimited communities, particularly those of the capitalist market economy, collectively the professoriate acts otherwise. As a whole, faculty continue to churn out academic progeny through a long period of apprentissage for positions that, taken in aggregate, no longer exist. Intensified discourses and anxieties around professionalization emerge to fill this gap, both registering the latent crisis and suggesting a means for its overcoming. Building on these examples, the authors suggest that professionalization remains a tactic through which academic laborers self-discipline but that today such self-disciplining tends to operate through the contradictory entwinement of (worker) reproduction and (institutional) reputation. The article closes with a new figure: that of the “unprofessional,” suggesting that our task is to shift the expectations set by professionalization that our own reproduction can only be ensured through its congealment in the commodity of reputation.
Due Time
Authors: Maldonado David A. , Meiners Erica R. 
Published: April 2021

AbstractAt this political moment within the university, mass incarceration and its most recognizable constituents, the prisoner and the prison, are at a predictable tipping point: the violence of inclusion. Neoliberal multiculturalism appears capacious enough to hold select representations of mass incarceration in its pursuit of new markets and deft enough to deploy this difference to whitewash other forms of institutional violence. Building from a long genealogy of scholarship and organizing that maps the coconstitutiveness of the university with our prison-industrial complex, this essay makes visible emergent lines and arrangements of power and resistance that inhibit and build abolition.
Characterization of epithelial domains in the nasal passages of chick embryos: spatial and temporal mapping of a range of extracellular matrix and cell surface molecules during development of the nasal placode
Authors: Croucher S. J. , Tickle C. 
Published: April 2021

ABSTRACTThe formation of the nasal passages involves complex morphogenesis and their lining develops a spatially ordered pattern of differentiation, with distinct domains of olfactory and respiratory epithelium. Using antibodies to the neural cell adhesion molecule (N-CAM), keratan sulphate and heparan sulphate proteoglycan (HSPG) and a panel of lectins (agglutinins of Canavalia ensiformis (ConA), Dolichos biflorus (DBA), peanut (PNA), Ricinis communis (RCA1), soybean (SBA), Ulex europaeus (UEA1), and wheatgerm (WGA)), we have documented cell surface characteristics of each epithelial domain. Binding of antibodies to N-CAM and to keratan sulphate, and the lectins ConA, PNA, RCA1, SBA and WGA marks the olfactory epithelial domain only. The restriction of N-CAM to the sensory region of the epithelium has also been reported in the developing ear. This striking similarity is consistent with the idea that N-CAM may be involved in the division of functionally and histologically distinct cell groups within an epithelium.We traced the olfactory-specific cell markers during development to gain insights into the origin of the epithelial lining of the nasal passages. AU reagents bind at early stages to the thickened nasal placode and surrounding head ectoderm and then become progressively restricted to the olfactory domain. The expression of these characteristics appears to be modulated during development rather than being cell autonomous.The distribution of keratan sulphate was compared with collagen type II in relation to the specification of the chondrocranium. Keratan sulphate and collagen type II are only colocalized at the epithelial-mesenchymal interface during early nasal development. At later stages, only collagen type II is expressed at the interface throughout the nasal passages, whereas keratan sulphate is absent beneath the respiratory epithelium.
Retinoic acid-induced spina bifida: evidence for a pathogenetic mechanism
Authors: Alles Ajit J. , Sulik Kathleen K. 
Published: April 2021

ABSTRACT
Treatment of C57B1/6J mice with three successive doses of all-trans retinoic acid (28 mg kg-1 body weight) on 8 day, 6h (8d,6h), 8d,12h, and 8d,18h of gestation resulted in a high incidence (79%, 31/39 fetuses) of spina bifida with myeloschisis (spina bifida aperta) in near term fetuses. Twelve hours following the last maternal dose (9d,6h), the caudal aspects of treated embryos, were abnormal, with eversion of the neural plate at the posterior neuropore, as compared to its normal concavity in comparably staged control specimens. This eversion persisted in affected embryos through the time that the posterior neuropore should normally close. The distribution of cell death in control and experimental embryos was determined using vital staining with Nile blue sulphate and with routine histological techniques. Twelve hours following the maternal dosing regimen, experimental embryos showed evidence of excessive cell death, predominantly in the mesenchyme associated with the primitive streak and in the endoderm of the tail gut, both of which are readily identifiable sites of physiological cell death at this stage of development. In addition, the presumptive trunk neural crest cells located in the dorsal midline, cranial to the posterior neuropore, exhibited a marked amount of cell death in the experimental embryos. We propose that the major factor in the generation of spina bifida in this model is excessive cell death in the tail gut and mesenchyme ventral to the neuroepithelium of the posterior neuropore. This causes a disparity in growth between the ventral and dorsal regions of the tail causing the relatively faster growing dorsal region (the neural plate) to evert, preventing caudal neural tube closure. Mesenchymal deficiencies resulting from excessive cell death in the gastrulating mesoderm would also account for the lack of tail formation and the abnormally formed lumbosacral vertebrae observed in this model. Previous investigations have suggested that the pathogenesis of a number of retinoic acid-induced malformations is related to excessive cell death in regions of physiological cell death. The current investigation explores the role of this phenomenon in the pathogenesis of experimental spina bifida.
The Time-Dependent Mechanical Properties of the Human Heel Pad in the Context of Locomotion
Authors: Ker Robert F. 
Published: April 2021

ABSTRACT
Previous measurements of the mechanical properties of the heel pad, especially of the energy loss during a cycle of compressive loading and unloading, have given contrasting values according to whether the investigators used isolated single impacts (e.g. pendulum tests; energy loss approximately 48 %) or continuous oscillations (energy loss approximately 30 %). To investigate this discrepancy, rest periods were inserted between single compressive cycles, giving intermittent loading as in locomotion. The energy loss, measured as the percentage area of the hysteresis loop, was found to change linearly with the logarithm of the rest time. It was approximately 33 % when the rest time was 1 s. Each 10-fold increase in the rest time added approximately 3.7 % to the energy loss. Thus, with rest times appropriate to locomotion, the pad is far from fully relaxed. The springy heel pad may help to reposition the foot during the transfer of load from the heel to the forefoot. Information is also included on the load–deformation curves for the heel pad and the way in which these change with rest time. This is presented as equations which may be useful in future models relating the mechanical properties of the heel to either its structure or its function.
Effect of Chemical Anoxia on Protein Kinase C and Na+/K+-ATPase in Hepatocytes of Goldfish (Carassius Auratus) and Rainbow Trout (Oncorhynchus Mykiss)
Authors: Schwarzbaum Pablo J. , Bernabeu Ramón O. , Krumschnabel Gerhard , Biasi Christina , Wieser Wolfgang 
Published: April 2021

ABSTRACT
Protein kinase C (PKC) and Na+/K+-ATPase in hepatocytes from the anoxia-tolerant goldfish (Carassius auratus) and the anoxia-intolerant rainbow trout (Oncorhynchus mykiss) were studied to determine their role in the anoxic response of these cells. PKC and Na+/K+-ATPase activities were measured for up to 90 min in the absence (normoxia) and presence (chemical anoxia) of 2 mmol l−1 sodium cyanide. PKC activity of normoxic cells from both species remained constant for the entire experimental period. Addition of cyanide had no effect on PKC activity of trout cells, which was maintained at 25 % of maximal PKC activity. In goldfish hepatocytes, PKC activity remained constant at 56 % of maximal PKC activity for 30 min but fell to 27 % after 90 min of anoxic exposure.
ATPase activity was measured in hepatocytes exposed to 100 nmol l−1 phorbol-12,13-dibutyrate (PdBu), a treatment which enhanced PKC activity to its maximum level. In trout cells, there was no significant change in Na+/K+-ATPase activity whereas in goldfish hepatocytes a significant increase to about 150 % of the respective controls was observed. On the basis of the experimental evidence that in hepatocytes of goldfish (1) PKC and Na+/K+-ATPase activities decreased in parallel during chemical anoxia and (2) a stimulation of PKC activity by PdBu increased Na+/K+-ATPase activity, we postulate that PKC activity in goldfish, but not in trout, may be implicated in the Na+/K+-ATPase inhibition observed under anoxia.
Maintenance Of The K+ Activity Gradient in Insect Muscle Compared In Diptera and Lepidoptera: Contributions of Metabolic and Exchanger Mechanisms
Authors: Fitzgerald Elizabeth M. , Djamgoz Mustafa B. A. , Dunbar Stuart J. 
Published: April 2021

ABSTRACT
Using a comparative approach, the mechanisms involved in maintenance of the transmembrane K+ activity gradients in the larval body-wall muscles of two insects, Phormia terraenovae (Diptera) and Spodoptera exigua (Lepidoptera), have been investigated. Double-barrelled K+-selective microelectrodes were used to obtain simultaneous measurements of intracellular K+ activity and membrane potential, whilst ordinary microelectrodes were used to monitor input resistance. By application of a variety of general metabolic blockers, the K+ gradients in both P. terraenovae and S. exigua muscle were found to be maintained, at least in part, by a metabolic component. Differences in sensitivity to dinitrophenol of the two insects suggested that the ATP-dependence of maintenance of the K+ gradient was significantly higher in P. terraenovae than in S. exigua. Vanadate sensitivity suggested that both insects possess P-type ATPases. The K+ activity gradient in P. terraenovae muscles was also found to be ouabain-sensitive, indicating the involvement of a Na+/K+-ATPase. In contrast, the K+ gradient in S. exigua muscles proved to be totally insensitive to ouabain but sensitive to amiloride.
Application of the H+/K+-ATPase-specific inhibitor SCH 28080 suggested the presence of an H+/K+ pump similar to the mammalian gastric H+/K+-ATPase in the lepidopteran muscles. P. terraenovae muscles, however, were found to be totally insensitive to this inhibitor. Using the anion (Cl-)-dependent transport inhibitors bumetanide and SITS (4-acetamide-4-isothiocyanostilbene-2,2-disulphonic acid), P. terraenovae muscles were shown not to possess a Cl--dependent K+ transport mechanism. In contrast, a bumetanide-sensitive K+/Cl- cotransporter was likely to be involved in maintenance of the K+ gradient in S. exigua muscle. An additional SITS-sensitive Cl-/HCO3- exchanger could also have some indirect involvement in K+ maintenance through regulation of the inward Cl- gradient. The results are integrated in two ionic models, one for each insect, which could account for the bulk of K+ transport in the body-wall muscles of these insects.
Transient Hovering Performance of Hummingbirds Under Conditions of Maximal Loading
Authors: Chai Peng , Chen Johnny S. C. , Dudley Robert 
Published: April 2021

ABSTRACT
Maximal load-lifting capacities of six ruby-throated hummingbirds (Archilochus colubris) were determined under conditions of burst performance. Mechanical power output under maximal loading was then compared with maximal hovering performance in hypodense gas mixtures of normodense air and heliox. The maximal load lifted was similar at air temperatures of 5 and 25 °C, and averaged 80 % of body mass. The duration of load-lifting was brief, of the order of 1 s, and was probably sustained via phosphagen substrates. Under maximal loading, estimates of muscle mass-specific mechanical power output assuming perfect elastic energy storage averaged 206 W kg−1, compared with 94W kg−1 during free hovering without loading. Under conditions of limiting performance in hypodense mixtures, maximal mechanical power output was much lower (131 W kg−1, five birds) but was sustained for longer (4 s), demonstrating an inverse relationship between the magnitude and duration of maximum power output. In free hovering flight, stroke amplitude and wingbeat frequency varied in inverse proportion between 5 and 25 °C, suggesting thermoregulatory contributions by the flight muscles. Stroke amplitude under conditions of maximal loading reached a geometrical limit at slightly greater than 180 °. Previous studies of maximum performance in flying animals have estimated mechanical power output using a simplified actuator disk model without a detailed knowledge of wingbeat frequency and stroke amplitude. The present load-lifting results, together with actuator disc estimates of induced power derived from hypodense heliox experiments, are congruent with previous load-lifting studies of maximum flight performance. For ruby-throated hummingbirds, the inclusion of wingbeat frequency and stroke amplitude in a more detailed aerodynamic model of hovering yields values of mechanical power output 34 % higher than previous estimates. More generally, the study of performance limits in flying animals necessitates careful specification of behavioral context as well as quantitative determination of wing and body kinematics.