AUTHOREA
Log in Sign Up Browse Preprints
LOG IN SIGN UP

Preprints

Explore 22,873 preprints on the Authorea Preprint Repository

A preprint on Authorea can be a complete scientific manuscript submitted to a journal, an essay, a whitepaper, or a blog post. Preprints on Authorea can contain datasets, code, figures, interactive visualizations and computational notebooks.
Read more about preprints.

Progress of clinical application of speckle tracking echocardiography in Transcathete...
Zhiyu Guo
Zhiling Luo

Zhiyu Guo

and 4 more

June 23, 2022
The clinical application evaluation of non-invasive imaging in transcatheter aortic valve implantation has also gradually developed. The advantages of ultrasound are gradually revealed in the evaluation of cardiac function before, during and after surgery, as well as short-term and long-term follow-up. Speckle tracking echocardiography (STE) is a non-invasive and angle-dependent new ultrasound diagnostic technique, which is used to evaluate the multi-angle and multi-directional motion velocity, strain and strain rate of human myocardium. The prognosis, recovery and risk stratification have good predictive evaluation value. With the continuous development of new related technologies and parameters from STE, scholars continue to apply these new technologies and new parameters to the clinical evaluation of transcatheter aortic valve implantation. A review of the clinical application of aortic valve implantation.
Prescribing cascades in community-dwelling adults: a systematic review
Ann Doherty
Faiza Shahid

Ann Doherty

and 9 more

June 23, 2022
Abstract Background: The misattribution of an adverse drug reaction (ADR) as a symptom or illness can lead to the prescribing of additional medication, referred to as a prescribing cascade. The aim of this systematic review is to identify published prescribing cascades in community-dwelling adults. Methods: Systematic review reported in line with the PRISMA guidelines and pre-registered with PROSPERO. Electronic databases (Medline (Ovid), EMBASE, PsycINFO, CINAHL, Cochrane Library) and grey literature sources were searched. Inclusion criteria: Community-dwelling adults; Risk-prescription medication; Outcomes-initiation of new medicine to ‘treat’ or reduce ADR risk; Study type-cohort, cross-sectional, case-control and case-series studies. Title/abstract screening, full-text screening, data extraction and methodological quality assessment was conducted independently in duplicate. A narrative synthesis was conducted. Results: A total of 101 studies (reported in 103 publications) were included. Study sample sizes ranged from 126 to 11,593,989 participants and 15 studies examined older adults specifically (≥60 years). Seventy-eight of 101 studies reported a potential prescribing cascade including calcium channel blockers to loop diuretic (n=5), amiodarone to levothyroxine (n=5), inhaled corticosteroid to topical antifungal (n=4), antipsychotic to anti-Parkinson drug (n=4), and acetylcholinesterase inhibitor to urinary incontinence drugs (n=4). Identified prescribing cascades occurred within three months to one year following initial medication. Methodological quality varied across included studies. Conclusion and implications: Prescribing cascades occur for a broad range of medications. ADRs should be included in the differential diagnosis for patients presenting with new symptoms, particularly older adults and those who started a new medication in the preceding 12 months. Word count: 245
Coexistence of anti-MDA5 and anti-PL-7 in a patient with dermatomyositis: a case repo...
Hongyan Fu
Shaofeng  Sun

Hongyan Fu

and 6 more

June 23, 2022
Anti-melanoma differentiation-associated gene 5 (anti-MDA5) and anti-threonyl-tRNA synthetase (anti-PL-7) are myositis-specific autoantibodies, associated with rapidly progressive interstitial lung disease (RP-ILD). A 41-year-old woman presented productive cough, dyspnea, and muscle pain. Anti-MDA5 and anti-PL-7 were double-positive. The patient was diagnosed with dermatomyositis-associated ILD, and responded successfully to glucocorticoids and immunosuppressants.
SUBMUCOSAL ADMINISTRATION OF DEXAMETHASONE FOR DENTAL IMPLANT SURGERY
Dennis Flanagan

Dennis Flanagan

June 23, 2022
Dexamethasone can reduce post-operative pain and swelling. An appropriate administration of dexamethasone for dental surgical procedures may be local submucosal infiltration. Local delivery may produce a faster onset with more drug at the desired site of action. A single submucosal dose will unlikely produce side effects.
Diversity, relative abundance and distribution of medium and large mammals in Mago Na...
Girma Mengesha

Girma Mengesha

June 23, 2022
The objective of this study was to investigate diversity, relative abundance, and distribution of medium and large mammals in Mago National Park (MNP), Southern Ethiopia. Data collection was conducted during dry and wet seasons. A systematic sampling design was used to establish line transects along the three main habitat types, namely: Woodland, Acacia savanna, and Riverine forest. A total of 45 line transects were established through the habitats, varing in length from 1.5 to 5 km, depending on the size of the habitat. Twenty-eight medium and large mammals species were recorded in the area belonging to 8 families and 5 orders. Order Artiodactyla had the highest number of species (14 species), followed by Carnivora (8 species), whereas Perissodactyla and Proboscidea were represented by one species each. During both seasons, the highest species diversity (H’ = 2.81, and H’=2.96) was recorded in woodland habitat, but the lowest ( H’ =2.5 and H’= 2.67) in riverine forest. In terms of abundance, Tragelaphus imberbis 1773±86 (12%) was the most abundant species, while Vulpes chama was the least abundant species 104 ±13 that contributed less than 1% of the total. Most of the mammals species occurred in woodland habitat as compared to the other habitat types. Seasonal variation in abundance (number) of individuals of medium and large mammals was significantly different (X2 = 91.651, df =1, p<0.05). However, variation in species composition was not significant (X2 = 0.018, df = 1, P<0.05). It can be concluded that, Mago National Park harbour high species diversity of medium and large mammals. Conservation efoforts that could suatain the high diversity pf the species in the area in needed to main the diversity.
Three‐dimensional Mapping System Facilitated Superior Approach for Radiofrequency Abl...
Chu-Yu Hsu
Shih-Lin Chang

Chu-Yu Hsu

and 15 more

June 23, 2022
Catheter ablation for tachyarrhythmia via superior approach has been used in patients without possible inferior vena cava access such as in cases of venous occlusion or complex anomaly. Difficulty in catheter manipulation, instability, number of required vascular access, and radiation exposure of operator had been described in the procedure. Application of three-dimensional (3-D) mapping system in catheter ablation via superior approach could navigate the guiding catheter and provide more precise ablation. We reported four cases receiving catheter ablation due to atrioventricular nodal reentry tachycardia, atrial fibrillation and right ventricular arrhythmia via superior approach facilitated by 3-D mapping system with fewer vascular access and catheters.
When the Dreaded Happens: Atrio-esophageal fistula post Atrial Fibrillation Catheter...
Aamer Ubaid
Vinay Jahagirdar

Aamer Ubaid

and 5 more

June 23, 2022
Though rare, atrio-esophageal fistula is the second most common complication of cardiac catheter ablation for atrial fibrillation; acute cardiac tamponade being the leading cause [1]. We report a case of a 64-year-old male with AEF after a catheter ablation procedure for AF, that proved to be fatal.
Biuret toxicity induces accumulation of nitrogen-rich compounds in rice plants
Kumiko Ochiai
Yosuke Nomura

Kumiko Ochiai

and 3 more

June 23, 2022
Excess biuret, a common impurity in urea fertilizers, is toxic to plants. Little is known about the mechanisms of biuret toxicity in plants. A previous study had shown that transgenic rice ( Oryza sativa) plants overexpressing bacterial biuret hydrolase improved biuret tolerance. Additionally, the biuret hydrolase-overexpressing plants showed a higher 15N ratio than wild-type plants when the roots were fed 15N-labeled biuret. Here, we determined biuret accumulation in rice seedlings by directly measuring the biuret. We found that the biuret hydrolase-overexpressing plants did not contain biuret, whereas wild-type plants accumulated biuret in shoots in the order of mmol L -1 tissue water. We also found that the concentration of allantoin, a nitrogen-rich intermediate compound in the purine degradation pathway, in rice shoots under biuret toxicity was higher than those in control conditions. Inhibition of allantoinase activity by biuret was not detected, and allantoin accumulation appeared to be associated with changes in the expression of putative allantoin transporter genes. Furthermore, another nitrogenous compound citrulline, which is a nonprotein amino acid, accumulated in rice suspension cells under biuret toxicity. The accumulation of these two nitrogen-rich compounds suggests that rice plants subjected to biuret toxicity may need to reduce the generation of surplus ammonium ions.
Invited commentary on “Risk Factors for Cerebrovascular Accident after Isolated Coron...
Salvior Mok

Salvior Mok

June 23, 2022
This paper, among other findings, affirmed Society of Thoracic Surgeons' published risk model for stroke after isolated CABG, that pre-existing cerebrovascular disease, prior MI, reduced EF and poor renal function as independent risk factors for peri-operative CVA.
Recurrence of Carney complex atrial myxoma causing Lung nodules
Jie Wang,M.D.
Ping Hu

Jie Wang,M.D.

and 4 more

June 23, 2022
Background Myxomas are the most common form of benign primary cardiac tumor, most of them are located in the left atrium. When they are located in the right atrium, It may occur with pulmonary artery embolism. Methods and Results A 72-year-old woman had endured more than 5 months with chest tightness and difficulty breathing. Based on various clinical findings and data, we diagnosed this subject as Cushing’s syndrome. Emergency bedside ultrasound showed right atrial tumor, which was confirmed by coronary computed tomography angiography (CCTA).The patient underwent surgical resection of the right atrial and pulmonary artery tumors.In the two subsequent short-term reviews (one month and half a year after surgery), we found same new myxoma in the atrial septum and pulmonary nodules. Discussion Tumor recurrence is uncommon, although not unknown, after complete excision. Recurrence following surgical excision is rare, with an incidence of only 1%–3% of all myxomas, and the postoperative course is generally good. However, some myxomas occur as part of a syndrome known as Carney complex, which have some unusual features. Conclusion They face a mottled skin pigmentation, and gorgeous features of Cushing’s syndrome. Myxomas recurrence have been reported in numerous reports. In contrast with other reported cases, a specific characteristic of the present case was the short-term recurrence of Cardiac myxoma and newly grown nodules in the lungs. Patients received our recommendations for lifetime anticoagulation therapy and long-term follow-up observations.
Successful Ablation of a Wide Complex Tachycardia with Distinct Intra-Cardiac Electro...
yuval konstantino
Kirill Buturlin

yuval konstantino

and 6 more

June 23, 2022
A 13-year-old boy was hospitalized after a syncopal episode that occurred during exercise. He suddenly felt chest tightness, sweating and palpitations, followed by a transient loss of conciseness. Upon emergency medical team arrival, he was awake and oriented. Baseline ECG showed sinus rhythm at a rate of 98 bpm, with narrow QRS, and no signs of long QT, Brugada, or pre-excitation. Physical examination, blood tests, 24 hours Holter monitoring, transthoracic echocardiography and stress test were all within normal limits. Eight days later he experienced a second episode of palpitations while walking to school. ECG revealed regular wide complex tachycardia (WCT) at a rate of 200 bpm, with LBBB morphology that terminated with Adenosine (Figure 1). The clinical tachycardia was easily induced by programmed electrical stimulation (Figure 2A). Diagnostic electrophysiological maneuver (Figure 2B) was followed by successful ablation, during which a unique phenomenon was noted (Figure 3). What is the diagnosis of the tachycardia and what are the unique findings noted during and after ablation?
Computing Neighborhood Degree based TI's of Supercoronene and Triangle-shaped Discoti...
S Govardhan
Roy Santiago

S Govardhan

and 3 more

June 23, 2022
For a long time, the structure and characteristics of benzene and other arenes have piqued researchers curiosity in quantum chemistry. The structural features of polycyclic aromatic compounds, like the fundamental molecular topology, have a strong influence on their chemical and biological properties. Quantitative structure-activity and property relationship (QSAR/QSPR) techniques for predicting characteristics of polycyclic aromatic compounds (PAC) and related graphs from chemical structures have been developed in this approach. To obtain degree-based topological indices, we have many polynomials. The neighbourhood M-polynomial is one of these polynomials, which is used to produce a number of topological indices based on neighborhood degree sum. In this study, we offer the exact analytical expressions of neighborhood M-polynomial and their corresponding topological indices for supercoronene (SC), cove-hexabenzocoronene (cHBC), and triangular-shaped discotic graphene (TDG) with hexabenzocorenene (HBC) as the base molecule. The findings could help with the development of physicochemical characteristic prediction.
Reproducibility and Replicability of Flood Models -- A Discussion
Bandana Kar
Guy Schumann

Bandana Kar

and 1 more

June 22, 2022
Flooding is a frequent disaster that has a wide-spread footprint globally with significant financial and societal impacts. With availability of Earth observation data from private and public entities at varying spatial, temporal, and spectral resolution as well as data from crowdsourcing, there is no shortage of models. In fact, models and algorithms are abundant and proliferating. However, the question remains where is a global flood model when we need one? Just because models are available does not mean they are usable or accessible and adequate for emergency managers, first responders and other stakeholders who use the model outputs for preparedness, response and resource planning. Often the issue of usability stems from the fact that the models are not always reproducible or replicable. The accuracy and uncertainty associated with the models and how they change based on the scale of analysis and the resolution of input and output datasets are often not communicated properly to stakeholders so they can be part of their decision-making process. The proliferation of machine learning and data driven models that rely on historical data also adds to this problem. This paper discusses several important issues associated with global flood models and provides recommendations that could be used to increase the usability of these models.
Soil bacterial communities are influenced more by forest type than soil depth or slop...
Jiyun She
Yun Wang

Jiyun She

and 5 more

June 22, 2022
Soil depth, slope position and different plantations can influence bacterial community composition in Camellia oleifera forests. However, prior studies have focused on the impacts of different depths, slope positions, and forest types on bacterial diversity independently, without comparing their combined impacts. This study aimed to assess variation in soil bacterial community structures according to soil depth and slope position and different forest types in the same plot. The composition of soil bacterial communities was evaluated using high-throughput sequencing of the 16S rRNA gene. Results indicate that the soil organic carbon, humus, and total organic content increased, and the bacterial composition and structure were significantly altered in response to the G. jasminoides + C. oleifera low-yielding forest in comparison to the other three forest types. The highest soil bacteria numbers, Alpha and beta diversity, which improved the soil microecological environment, were associated with the G. jasminoides + C. oleifera forests and not the depth or slope position treatments. The slope position did not have a significant influence on the soil physicochemical and bacterial properties. Structural equation modeling suggested that G. jasminoides + C. oleifera significantly affected the soil bacterial community diversity by mediating the soil pH and NH 4–N. The effects of forest type on soil bacterial diversity were more important than soil depth and slope position. This specific intercropping system was found to be an effective strategy to improve soil health.
Structure and characteristics of plant-frugivore network in Guilin Botanical Garden
GuoHai Wang
Yang Huang

GuoHai Wang

and 7 more

June 22, 2022
The interaction between plants and frugivores plays a critical role in sustaining ecosystem function and community diversity, but little is known about the structure of interaction networks between fruit plants and frugivore birds in urban green spaces. We observed the interactions between plants and birds throughout the year in the Guilin Botanical Garden and assessed the characteristics of the total plant-frugivore and seasonal networks. We also analyzed the relationship between the network roles of species and ecological traits to explore the structure and characteristics of the plant-frugivore network. The interactions between a total of 14 frugivore birds and 13 fruit plant species were analyzed in the study area, the autumn and winter interaction connections contributed 38.79% and 33.15% to the total network, respectively. The specialization (H2´), and interaction evenness (E2) of the network were higher in spring and summer than that in autumn and winter. However, connectance (C), nestedness, and interaction diversity (H2) were contrary to the specialization and interaction evenness of the network. Compared to the networks (N=1000) generated by the null model, the observed network exhibited lower connectance (C), interaction diversity(H2), interaction evenness (E2), and higher nestedness and specialization (H2´). A correlation analysis combining ecological traits and network roles showed that plants with black fruit had higher species strength, whereas the other traits of plants and birds were not significantly correlated with their network parameters.
Current Status of Pediatric Oncology Nursing in Africa: Perspective of African nurses...
Glenn Afungchwi

Glenn Afungchwi

and 6 more

June 22, 2022
Authors: G.M. Afungchwi1, E. Kiteni2, M. Ndagire3, B. Maliti4, R. Kunkel5, J. Challinor6, R. Hollis71 = Cameroon Baptist Convention Health Services, Bamenda, Cameroon2 = Muhimbili National Hospital, Pediatric Oncology Unit, Tanzania3 = Uganda Cancer Institute, Kampala, Uganda4 = Zambia Cancer Diseases Hospital, Lusaka, Zambia5 = Arkansas Children’s Hospital, Arkansas, USA6 = University of California San Francisco, San Francisco, California, USA7 = Leeds Children’s Hospital, Leeds, UKAddress correspondences to Dr Glenn Mbah Afungchwi, Cameroon Baptist Convention Health Services, Department of Pediatric Oncology, Bamenda, Cameroon. Email: mbahlos@gmail.com Tel: (+237)675959629
Study on the Interaction Mechanism between Phospholipase A1 from Serratia marcescens...
Zhou Jie
Yang Meng

Zhou Jie

and 7 more

June 22, 2022
Previous studies showed a sequence encoding an auxiliary protein (PlaS) downstream of the phospholipase A1 (PlaA1) gene of Serratia marcescens. There is an interaction between PlaA1 and PlaS, which may be closely related to the high enzymatic activity property of phospholipase A1. In order to further investigate the interaction mechanism, it is necessary to explore binding sites of the interaction between PlaA1 and PlaS and the regulatory mechanism for enzymatic properties by molecular docking and site-directed mutagenesis. The results showed that the active center site of PlaA1 was encapsulated internally, and a “catalytic pocket” was formed externally by Leu197-Ser249. The docking process of PlaA1 and PlaS involved 29 and 30 amino acids, respectively, of which Phe186 and Lys238 of PlaA1 are involved in forming π-bonds and multiple hydrogen bonds. Therefore, Phe186 and Lys238 were site-directed mutated to Ala to obtain the mutant enzymes PlaA1 F186A and PlaA1 K238A, respectively. The results showed that the mutant enzymes showed no significant changes in optimum temperature and pH but poor stability. The kinetic parameters indicated that the affinity between PlaA1 and substrates was weakened, and the catalytic efficiency was reduced after mutation. Therefore, it demonstrated that Phe186 and Lys238 of PlaA1 provided non-covalent bonds conducive to the enzymatic activity and stability in the interaction between PlaA1 and PlaS, which would provide some theoretical basis for further rational design and modification of phospholipase A1 subsequently.
Experimental evidence for nature's hidden network of higher-order interactions
Milton Barbosa
G. Fernandes

Milton Barbosa

and 2 more

June 22, 2022
Transcending pairwise interactions in ecological networks remains a challenge. Higher-order interactions, the modulation of a pairwise interaction by a third species, have so far only been demonstrated in models or small isolated systems. Their ubiquity at a community level remains unknown. Using field experiments, we tested how multiple interactions within a network changed with species composition by reducing the densities of distinct species in a diverse arthropod community. We revealed an extensive hidden network of higher-order interactions modifying each other and the “visible” direct interactions. Most pairwise interactions were affected by the manipulation of a non-interacting taxonomic group. The pervasiveness of these interaction modifications challenges pairwise approaches to understanding interaction outcomes and could shift our thinking about the structure and resilience of ecological communities.
Pattern and Predictors of Medication Use among Adults in Southwestern Nigeria: A Comm...
Waheed Adedeji
Magbagbeola David  Dairo

Waheed Adedeji

and 4 more

June 22, 2022
Aim: The aim was to determine the pattern and predictors of medication use among adults in the communities of Southwestern Nigeria. Methods: A cross-sectional study was conducted among adults selected by multi-stage sampling from Oyo State communities. The questionnaires, adapted from the WHO Students’ Drug Use Questionnaire and previous studies, were pretested and interviewer-administered. The respondents’ socio-demographic characteristics, the pattern of medication use, prescribers and sources of drug acquisition were obtained. Binary logistic regression was used to determine the predictor of medications used. Results: Of the 999 respondents, 501 resided in rural communities while 498 dwelled in urban areas. The mean (±SD) age of the respondents was 38±15years. The median (range)% prevalence of medication use were: lifetime use, 58.2(17.7-81.0), current use, 31.2(8.9-65.9) and past use, 20.3(9.2-28.9). Medications were mainly obtained from patent medicine stores, median (range%), 71(65-80). The commonly used drugs were paracetamol,626(67.6), Nonsteroidal anti-inflammatory drugs, 174(18.8), artemether/lumefantrine, 422(68.2), Ampicillin/cloxacillin, 220(48.6), and chlorpheniramine, 59(40.4). Factors predictive of current medication use, AOR (95% CI) were: antimalarial [male, 0.7(0.5, 0.9)]; antibacterial [male, 0.6(0.4-0.9)]; analgesics [married, 1.5(1.1-2.2), presence of health facilities, 0.5(0.3-0.7), and shorter distance to health facility, 1.5(1.1-2.1)]. Conclusion: Antimalarials, antibacterial and analgesics were commonly used and inappropriately obtained by adults in Southwestern Nigeria. Factors predictive of current medication use were gender, marital status, the presence of health facilities and distance to health facilities. There is a need for more extensive countrywide medication use studies and enlightenment programs to ensure the appropriate use of medications.
First chromosome scale genomes of ithomiine butterflies (Nymphalidae: Ithomiini): com...
Jérémy GAUTHIER
Joana Meier

Jérémy GAUTHIER

and 23 more

June 22, 2022
The ithomiine butterflies (Nymphalidae: Danainae) represent the largest known radiation of Mullerian mimetic butterflies. They dominate by number the mimetic butterfly communities, which include species such as the iconic neotropical Heliconius genus. Despite recent studies carried out on ithomiine ecology and genetic structure, no reference genome was available for the tribe. Here, we generated high-quality, chromosome-scale genome assemblies of two Melinaea species, Melinaea marsaeus and Melinaea menophilus, and a draft genome of Ithomia salapia. We obtained genomes with a size ranging from 396 Mb to 503 Mb across the three species and scaffold N50 of 40.5 Mb and 23.2 Mb for the two chromosome-scale assemblies. Using collinearity analyses we identified massive rearrangements between the two closely related Melinaea species. A detailed annotation of transposable elements and genes was performed, resulting in the identification of 24,341, 31,081 and 31,976 genes in I. salapia, M. marsaeus and M. menophilus, respectively. We used a specialist annotation to target chemosensory genes, which is crucial for host plant detection and mate recognition in mimetic species. A comparative genomic approach revealed independent gene expansions in ithomiines and particularly in gustatory receptor genes. These first three genomes of ithomiine mimetic butterflies constitute a valuable addition and a welcome comparison to existing biological models of mimicry, such as Heliconius, and will enable further understanding of the mechanisms of adaptation and the genetic bases underpinning mimicry.
Left Main and Two Vessels Coronary Aneurysms Presented as Out of Hospital Cardiac Arr...
Khaled Al Khodari
Raad Alhaj Tahtouh

Khaled Al Khodari

and 3 more

June 22, 2022
A 37-year-old patient was admitted secondary to ventricular fibrillation induced out of hospital cardiac arrest. Coronary angiogram revealed left main, left anterior descending, and right coronary arteries aneurysms. The patient underwent bypass surgery with 4 grafts. Ejection fraction improved from 30% upon admission to 45% at 3-months’ follow up.
Successful desensitization after hypersensitivity reaction to cisplatin in a patient...
Arisa Kinouchi
Hiroki Ishii

Arisa Kinouchi

and 3 more

June 22, 2022
Hypersensitivity reaction (HSR) to cisplatin can result in discontinuation of chemoradiotherapy in patients with head and neck squamous cell carcinoma (HNSCC). We present a nasopharyngeal carcinoma patient with cisplatin hypersensitivity successfully treated with cisplatin-desensitization. Desensitization therapy may be safe and beneficial in patients with HNSCC who develop HSR to cisplatin.
Higenamine ameliorated myocardial ischemia/reperfusion injury via Prx2 and arginine m...
Fei Zhao
Kai Tang

Fei Zhao

and 11 more

June 22, 2022
Background and Purpose Myocardial ischemia/reperfusion (MI/R) injury is the main clinical problem of coronary heart disease. Higenamine (HG), a cardiotonic active component isolated from aconiti tuber, exhibits cardioprotective effects. However, its exact mechanism in MI/R is limited. Experimental Approach The oxidative stress induced by H2O2 in H9c2 and MI/R rat model was established. Metprolol, evidenced to ameliorate MI/R injury, was used as the positive control. Cardiac impairment indexes, were detected in vitro and in vivo. Changes of peroxiredoxins (Prxs), important anti-oxidative stress proteins in MI/R were also evaluated. Adenovirus induced Prx2 down-regulation and specific inhibitor of Prx2 was employed to determine the exact mechanism of HG in vitro and in vivo. Metabolomic analysis of MI/R rats with or without HG administration based on UPLC-MS/MS was further performed. Key Results HG significantly reduced the oxidative stress, improve cardiac dysfunction and decrease cardiac infarct size against MI/R via Prx2 activation, which was stronger than those in positive control treated rats. Additionally, HG altered metabolism of arginine and proline and biosynthesis of arginine during MI/R. Mechanically, HG increased the levels of Prx2, accompanied with decreased apoptotic protein, in vitro and in vivo expressions. However, down-regulation of Prx2 markedly blocked all the cardioprotective effect of HG. Conclusion and Implications Our work systematicly demonstrated that HG possessed a strong cardioprotective effect against MI/R by up-regulating cardiac expression of Prx2 and modulating disordered metabolism of arginine and glutamine in heart. We provided HG as the potential to further explore therapeutic strategy for MI/R.
Effect of different doses of dexmedetomidine on the median effective concentration of...
Hai-yan  Chen
Fang Deng

Hai-yan Chen

and 5 more

June 22, 2022
Background: Dexmedetomidine could be an ideal adjuvant to propofol during gastrointestinal endoscopy because it provides both analgesia and sedation without respiratory depression. This study investigates the effect of different doses of dexmedetomidine on the median effective concentration of propofol during gastrointestinal endoscopy. Methods: 90 adult patients were randomly assigned to Group Control , Group DEX0.5 (0.5 μg/kg dexmedetomidine), or Group DEX1.0 (1.0 μg/kg dexmedetomidine) . Anaesthesia during endoscopy was implemented by plasma target-controlled infusion (TCI) of propofol with different doses of dexmedetomidine. TCI concentration of the first patient for each group was 2.5 μg/ml and the consecutive adjacent concentration gradient was 0.5 μg/mL. EC50 of TCI propofol for gastrointestinal endoscopy was determined by using the modified Dixon’s up-and-down method. Cardiovascular variables were also measured. Results: EC50 of TCI propofol and 95% confidence interval (CI) for gastrointestinal endoscopy were, 3.77 (3.48-4.09), 2.51 (2.27-2.78) and 2.10 (1.90-2.33) μg/mL in Group Control, Group DEX0.5 and Group DEX1.0. The average percent change from baseline in HR was 2.8 (8.9), -7.4 (7.7) and -10.5 (8.8) (P<0.001), and the average percent change from baseline in MAP was -10.6 [-24.7; 3.5], -9.5 [-29.2; 11.4] and -4.0 [-27.3; 15.5] (P = 0.034) in Group Control, Group DEX0.5 and Group DEX1.0, respectively. Conclusions: Dexmedetomidine reduced the EC50 of TCI propofol. A 0.5-1 μg/kg dexmedetomidine caused a decrease in HR without bradycardia. The decrease in dosage of propofol with increasing doses of dexmedetomidine caused more stable MAP. Dexmedetomidine is an ideal adjuvant drug to propofol during gastrointestinal endoscopy.
← Previous 1 2 3 4 5 6 7 8 9 10 11 … 953 954 Next →
Authorea
  • Home
  • About
  • Product
  • Preprints
  • Pricing
  • Blog
  • Twitter
  • Help
  • Terms of Use
  • Privacy Policy