REVIEW | doi:10.20944/preprints202011.0443.v1
Subject: Medicine & Pharmacology, Allergology Keywords: opiate; mu; kappa; delta; nociceptin; addiction; overdose; prenatal; postnatal
Online: 17 November 2020 (09:53:19 CET)
Buprenorphine, an analogue of thebaine, is a Schedule III opioid in the United States used for opioid-use disorder and as an analgesic. Research has shown drugs like buprenorphine have a complicated pharmacology with characteristics that challenge traditional definitions of terms like agonist, antagonist, and efficacy. Buprenorphine has a high affinity for the mu (MOR), delta (DOR), kappa (KOR), and intermediate for the nociceptin opioid receptors (NOR). Buprenorphine is generally described as a partial MOR agonist with limited activity and decreased response at the mu-receptor relative to full agonists. In opioid naïve patients, the drug’s analgesic efficacy is equivalent to a full MOR agonist, despite decreased receptor occupancy and the “ceiling effect” produced from larger doses. Some argue buprenorphine’s effects depend on the endpoint measured, as it functions as a partial agonist for respiratory depression, but a full-agonist for pain. Buprenorphine’s active metabolite, norbuprenorphine, attenuates buprenorphine's analgesic effects due to NOR binding and respiratory depressant effects. The method of administration impacts efficacy and tolerance when administered for analgesia. There have been eleven-thousand reports involving buprenorphine and minors (age < 19) to US poison control centers, the preponderance (89.2%) with children. The consequences of prenatal buprenorphine exposure in experimental animals and humans should continue to be carefully evaluated. In conclusion, buprenorphine’s characterization as only a partial mu-agonist is an oversimplification. Contemporary research shows the traditional explanation of the pharmacology of buprenorphine does not take into account changes to receptor theory, pharmacological terminology, route of administration, and biologically active major metabolites.
Subject: Medicine & Pharmacology, Allergology Keywords: triple-negative breast cancer; prognosis; immune system; immunoglobulin kappa C
Online: 31 May 2021 (12:27:49 CEST)
We studied the prognostic impact of tumor immunoglobulin kappa C (IGKC) mRNA expression as a marker of the humoral immune system in the FinHer trial patient population, where 1,010 patients with early breast cancer were randomly allocated to either docetaxel-containing or vinorelbine-containing adjuvant chemotherapy. HER2-positive patients were additionally allocated to either trastuzumab or no trastuzumab. Hormone receptor-positive patients received tamoxifen. IGKC was evaluated in 909 tumors using quantitative real-time polymerase chain reaction, and the influence on distant disease-free survival (DDFS) was examined using univariable and multivariable Cox regression and Kaplan-Meier estimates. Interactions were analyzed using Cox regression. IGKC expression, included as continuous variable, was independently associated with DDFS in a multivariable analysis including also age, molecular subtype, grade, and pT and pN stage (HR 0.930, 95% CI 0.870 – 0.995, P = 0.034). An independent association with DDFS was also found in a subset analysis of triple-negative breast cancers (TNBC) (HR 0.843, 95% CI 0.724 – 0.983, P = 0.029), but not in luminal (HR 0.957, 95% CI 0.867 – 1.056, P = 0.383) or HER2-positive (HR 0.933, 95% CI 0.826 – 1.055, P = 0.271) cancers. No significant interaction between IGKC and chemotherapy or trastuzumab administration was detected (Pinteraction = 0.855 and 0.684, respectively). These results show that humoral immunity beneficially influences the DDFS of patients with early TNBC.
Subject: Life Sciences, Other Keywords: Dopamine, Kappa Opioid Receptors, Ventral Tegmental Area, Nucleus Accumbens, Prefrontal Cortex
Online: 12 July 2019 (13:10:41 CEST)
Neural circuits that enable an organism to protect itself by promoting escape from immediate threat and avoidance of future injury are conceptualized to carry an “aversive” signal. One of the key molecular elements of these circuits is the kappa opioid receptor (KOR) and its endogenous peptide agonist, dynorphin. In many cases, the aversive response to an experimental manipulation can be eliminated by selective blockade of KOR function, indicating its necessity in transmitting this signal. The dopamine system, through its contributions to reinforcement learning, is also involved in processing of aversive stimuli, and KOR control of dopamine in the context of aversive behavioral states has been intensely studied. In this review, we have discussed the multiple ways in which the KORs regulate dopamine dynamics with a central focus on dopamine neurons and projections from the ventral tegmental area. At the neuronal level, KOR agonists inhibit dopamine neurons both in the somatodendritic region as well as at terminal release sites, through various signaling pathways and ion channels, and these effects are specific to different synaptic sites. While the dominant hypotheses are that aversive states are driven by decreases in dopamine and increases in dynorphin, reported exceptions to these patterns indicate these ideas require refinement. This is critical given that KOR is being considered as a target for development of new therapeutics for anxiety, depression, pain, and other psychiatric disorders.
ARTICLE | doi:10.20944/preprints201812.0085.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: chitosan; kappa-carrageenan; polyelectrolyte complex; gold nanoparticles encapsulation; glucose oxidase; bionanocomposite.
Online: 6 December 2018 (13:15:35 CET)
In this work, an enzymatic sensor, based on a bionanocomposite film consisting of a polyelectrolyte complex (PEC) [Chitosan/kappa-carrageenan] doped with gold nanoparticles (AuNPs) encapsulating glucose oxidase (GOD) deposited on a gold electrode (Au) for glucose sensing, is described. Using the electrocatalytic synergy of AuNPs and GOD as a model of enzyme, the variation of the current (µA) as a function of the log of the glucose concentration (log [glucose]), shows 3 times higher sensitivity for the modified electrode (283.9) compared to that of the PEC/GOD modified electrode (93.7), with a detection limit of about 5 µM and a linearity range between 10µM and 7mM. The response of the PEC/AuNPs/GOD based biosensor also presents good reproducibility, stability and negligible interfering effects from ascorbic acid, uric acid, urea and creatinine. The applicability of the PEC/AuNPs/GOD based biosensor was tested in glucose-spiked saliva samples and acceptable recovery rates were obtained.
ARTICLE | doi:10.20944/preprints202103.0241.v1
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: $(\kappa,\mu,\nu)$-space, pseudoparallel, Ricci-generalized pseudoparallel and 2-pseudoparallel submanifolds.
Online: 9 March 2021 (07:38:10 CET)
In this article, the geometry of pseudoparallel, Ricci-generalized pseudoparallel and 2-Ricci-generalized pseudoparallel invariant submanifolds of an almost $\alpha$-cosymplectic $(\kappa,\mu,\nu)$ space has been searched under the some conditions. We also give some characterizations for such submanifolds. I think that obtained new results contribute to differential geometry.
ARTICLE | doi:10.20944/preprints202003.0095.v1
Subject: Medicine & Pharmacology, Other Keywords: CLSI; EUCAST; ESBL Urinary tract infections; Escherichia coli; Klebsiella pneumoniae; Kappa coefficient
Online: 5 March 2020 (14:58:31 CET)
Aims: The lack of information about the inter variability of the test results obtained by CLSI and EUCAST requires further clarifications to interpret antimicrobial susceptibility patterns better. This study aimed to compare the CLSI and EUCAST interpretations of the antimicrobial susceptibility test results of the ESBL–producing uropathogenic Escherichia coli and Klebsiella pneumonia strains. Methods: After obtaining 157 ESBL-producing E. coli and 95, ESBL-producing K. pneumonia isolates from the urine specimens of the patients, Kirby-Bauer’s disc diffusion method was used for conducting antimicrobial susceptibility test. The test procedures and the interpretation of the results were carried out according to the year 2017 versions of both of the two guidelines. For the statistical comparison of concordance between the two guidelines, the Kappa coefficients and the concordance rates were calculated. Results: The results were graded in the range from perfect to poor agreement. For E. coli, interpretations of the AST results revealed a moderate to perfect agreement between both methods. Weighted Kappa agreement scores in the range from 0.42 to 1. The agreement for AMC, TPZ30/6, ceftazidime 10, meropenem, and aztreonam was poor without any inconsistencies. For Klebsiella, the kappa agreement score was in the range from 0.25 to 1. It was incompatible with AMC, TPZ 30/6, ceftazidime 10, aztreonam; there was poor agreement for cefepime, amikacin and ertapenem. Conclusions: Our results showed agreement between the two guidelines for uropathogenic extended-spectrum ß-lactamase producing Escherichia coli and Klebsiella pneumoniae but also showed inconsistencies between two guidelines. Therefore, the results of our study contribute to the comparison of these guidelines for interpreting antibiotic susceptibilities.
ARTICLE | doi:10.20944/preprints202211.0031.v1
Subject: Life Sciences, Molecular Biology Keywords: GPCRs; Kappa opioid receptor; Salvinorin A; Natural products; docking; molecular dynamics simulations; dynophores
Online: 1 November 2022 (14:20:16 CET)
The natural product Salvinorin A (SalA) was the first nitrogen-lacking agonist discovered for the opioid receptors and exhibits high selectivity for the kappa opioid receptor (KOR) turning SalA into a promising analgesic to overcome the current opioid crisis. Since SalA’s suffers from poor pharmacokinetic properties, particularly the absence of gastrointestinal bioavailability, fast metabolic inactivation and subsequent short duration of action, the rational design of new tailored analogs with improved clinical usability is highly desired. Despite being known for decades, the binding mode of SalA within the KOR remains elusive as several conflicting binding modes of SalA were proposed hindering the rational design of new analgesics. In this study, we rationally determined the binding mode of SalA to the active state KOR by in silico experiments (docking, molecular dynamics simulations, dynophores) in the context of all available mutagenesis studies and structure-activity relationship (SAR) data. To the best of our knowledge this is the first comprehensive evaluation of SalA’s binding mode since the determination of the active state KOR crystal structure. SalA binds above the morphinan binding site with its furan pointing towards the intracellular core while the C2-acetoxy group is oriented towards the extracellular loop 2 (ECL2). SalA is solely stabilized within the binding pocket by hydrogen bonds (C210ECL2, Y3127.35, Y3137.36) and hydrophobic contacts (V1182.63, I1393.33, I2946.55, I3167.39). With the disruption of this interaction pattern or the establishment of additional interactions within the binding site we were able to rationalize the experimental data for selected analogs. We surmise the C2-substituent interactions as important for SalA and its analogs to be experimentally active, albeit moderate frequency within MD simulations of SalA. We further identified the non-conserved residues 2.63, 7.35, and 7.36 responsible for the KOR subtype selectivity of SalA. We are confident that the elucidation of the SalA binding mode will promote the understanding of KOR activation and the facilitate the development of novel analgesics that are urgently needed.
ARTICLE | doi:10.20944/preprints202104.0170.v1
Subject: Biology, Anatomy & Morphology Keywords: abdominal subcutaneous adipocytes; angiotensinogen; nuclear factor-kappa B; lipopolysaccharide; tumor necrosis factor-alpha
Online: 6 April 2021 (11:28:00 CEST)
Central adiposity is one of the significant determinants of obesity-related hypertension risk, which may arise due to the abdominal fat depot's pathogenic inflammatory nature. Pro-inflammatory cytokines and adipokines up-regulation through nuclear factor-kappa B (NF-κB) activation in adipose tissue has been considered an essential function in the pathogenesis of obesity-related hypertension. This study aimed to ascertain the NF-κB inhibitor (SN50) effect on TNF-α and angiotensinogen (AGT) secretion and expression in mediating the anti-inflammatory effect through its impact on NF-κB activity in humans adipose tissue. Primary human adipocytes were isolated from 20 subjects among 10 overweight and 10 obese with and without hypertension and treated with 10ng/ml LPS in the presence and absence of NF-κB inhibitor, SN50 (50μg/ml). TNF-α secretion and NF-κB p65 activity were detected in supernatants extracted from cultured cells treated and untreated with LPS (10ng/ml) and SN50 (50μg/ml) using enzyme-linked immunosorbent assay (ELISA). The western blot technique detected the protein of NF-κB p65 and AGT. Gene expression of TNF-α and AGT was detected in cells and performed using quantitative real-time polymerase chain reaction (RT-PCR). Treatment of AbdSc adipocytes with LPS (10ng/ml) caused a significant increase in NF-κB p65 among overweight and obese subjects with and without hypertension (P= 0.001) at 24 hours incubation. In contrast, SN50-NF-κB inhibitor causes a reduction of NF-κB p65 in overweight (P= <0.001) and obese subjects with and without hypertension (P= 0.001) at 24 hours incubation. Treatment of AbdSc adipocytes with 10ng/ml LPS caused a significant increase in TNF-α secretion in overweight and obese subjects at all-time points (P= <0.001), whereas SN50 leads to a decrease in TNF-α secretion at 3 and 12 hours incubation. Treatment of AbdSc adipocytes with LPS (10ng/ml) caused increased TNF-α and AGT gene expression twofold compared with untreated cells, whereas, in the presence of SN50, it reduces mRNA AGT levels in both groups. Taken together, these adipokines with NF-κB activation may represent essential biomarkers to evaluate hypertension risk and to provide insight into the pathogenesis of obesity-related hypertension.
ARTICLE | doi:10.20944/preprints201911.0218.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Landsat; Google Earth; water index; unsupervised image classification; supervised image classification; Kappa coefficient
Online: 19 November 2019 (03:10:17 CET)
To address three important issues related to extraction of water features from Landsat imagery, i.e., selection of water indexes and classification algorithms for image classification, collection of ground truth data for accuracy assessment, this study applied four sets (ultra-blue, blue, green, and red light based) of water indexes (NWDI, MNDWI, MNDWI2, AWEIns, and AWEIs) combined with three types of image classification methods (zero-water index threshold, Otsu, and kNN) to 24 selected lakes across the globe to extract water features from Landsat-8 OLI imagery. 1440 (4x5x3x24) image classification results were compared with the extracted water features from high resolution Google Earth images with the same (or ±1 day) acquisition dates through computing the Kappa coefficients. Results show the kNN method is better than the Otsu method, and the Otsu method is better than the zero-water index threshold method. If the computational cost is not an issue, the kNN method combined with the ultra-blue light based AWEIns is the best method for extracting water features from Landsat imagery because it produced the highest Kappa coefficients. If the computational cost is taken into account, the Otsu method is a good choice. AWEIns and AWEIs are better than NDWI, MNDWI and MNDWI2. AWEIns works better than AWEIs under the Otsu method, and the average rank of the image classification accuracy from high to low is the ultra-blue, blue, green, and red light-based AWEIns.
ARTICLE | doi:10.20944/preprints202008.0553.v1
Subject: Social Sciences, Education Studies Keywords: disability statistics; kappa; intraclass correlation coefficient; young adolescents; functional difficulties; special education; survey; health behaviour
Online: 25 August 2020 (11:48:46 CEST)
Determining disability prevalence is an important area for population statistics, especially among young adolescents. The Washington Group on Disability Statistics is one source of reporting disabilities through functional difficulties. However, young adolescents self-reporting this measure is in its infancy. The purpose of this study was to carry out an intra-rater test-retest reliability study on a modified set of items for self-reporting functional difficulties. Young adolescents (n=74; boys=64%; age m=13.7, SD=1.8) completed a self-reported version of the child functioning module in a supervised classroom. The second administration took place two weeks later. Intraclass correlation coefficient (ICC) and Kappa (k) statistics were used to test reliability of the items, and interpretation through Landis & Koch, and Cohen, respectively. The majority of items had substantial or moderate agreement, although there was only fair agreement for self-care (ICC=0.59), concentration (ICC=0.50), and routine (ICC=0.54). Kappa statistics of behaviour were interpreted to be large (k=0.65), and seeing (k=0.49), walking (k=0.49), and speaking (k=0.49) difficulties were moderate. The majority of the items in the self-reported version of the child functioning module can be used in a scale format, although some caution may be required on items of self-care and concentration when used as a dichotomous variable.
REVIEW | doi:10.20944/preprints202208.0419.v1
Subject: Life Sciences, Other Keywords: Alcohol; Dynorphin; Kappa Opioid Receptor; DYN/KOR; Anxiety; Depression; Negative Affective States; Withdrawal; Microdialysis; Dynorphin-immunoreactivity
Online: 24 August 2022 (10:52:52 CEST)
Alcohol use disorder (AUD) represents major public and socioeconomic issues. Alcohol exerts its phar-macological effects by altering different neurotransmitter systems, such as g-aminobutyric acid (GABA), glutamate, opioids, etc. Recent evidence suggests that the dynorphin (DYN)/kappa opioid receptor (KOR) system mediates the negative affective states associated with alcohol withdrawal. This system is also in-volved in stress-mediated alcohol intake in alcohol-dependent subjects. The DYN/KOR system probably exerts its action in the central nucleus of the amygdala (CeA) to mediate the negative affective states as-sociated with alcohol withdrawal. This article aims to review the current literature regarding the role of the DYN/KOR system in the actions of alcohol. We first review the literature regarding the effect of alcohol on the level of the peptide and its receptor, and the role of the endogenous DYN/KOR system in alcohol reward and negative affective states associated with alcohol withdrawal is then discussed. We also review the literature regarding the effects of KOR ligands on these processes.
ARTICLE | doi:10.20944/preprints202108.0318.v1
Subject: Social Sciences, Education Studies Keywords: Inter-rater reliability; preservice teacher performance assessment; PACT; edTPA; weighted kappa; cognitive task analysis; qualitative; quantitative
Online: 16 August 2021 (10:51:52 CEST)
The Performance Assessment for California Teachers (PACT) is a high stakes summative assessment that was designed to measure pre-service teacher readiness. We examined the inter-rater reliability (IRR) of trained PACT evaluators who rated 19 candidates. As measured by Cohen’s weighted kappa, the overall IRR estimate was .17 (poor strength of agreement). IRR estimates ranged from -.29 (worse than expected by chance) to .54 (moderate strength of agreement); all were below the standard of .70 for consensus agreement. Follow up interviews of 10 evaluators revealed possible reasons we observed low IRR, such as departures from established PACT scoring protocol, and lack of, or inconsistent, use of a scoring aid document. Evaluators reported difficulties scoring the materials that candidates submitted, particularly the use of Academic Language. Cognitive Task Analysis (CTA) is suggested as a method to improve IRR in the PACT and other teacher performance assessments such as the edTPA.
ARTICLE | doi:10.20944/preprints201808.0197.v1
Subject: Biology, Plant Sciences Keywords: Cudratricusxanthone L; Cudrania tricuspidata; Neuroinflammation; Nuclear factor-kappa B (NF-κB); Mitogen-activated protein kinase (MAPK)
Online: 9 August 2018 (20:43:24 CEST)
Neuroinflammatory responses are implicated in the pathogenesis of neurodegenerative diseases. In neurodegenerative diseases, neuroinflammatory reactions to neuronal injury are modulated by microglial cells, which are vital innate immune cells in the central nervous system. Activated microglial cells release proinflammatory cytokines, mediators, and neurotoxic factors that induce fatal neuronal injury. The present study investigated the anti-neuroinflammatory effects of cudratricusxanthone L (1), which was isolated from Cudrania tricuspidata. This compound reduced the levels of lipopolysaccharide-stimulated inflammatory mediators and cytokines, including nitric oxide, prostaglandin E2, interleukin (IL)-1β, tumor necrosis factor-α, IL-6, and IL-12. These effects suggested that cudratricusxanthone L (1) suppressed the nuclear factor-kappa B (NF-κB) signaling pathway. Specifically, cudratricusxanthone L (1) also attenuated the phosphorylation of Jun kinase and inhibited p38 mitogen-activated protein kinase (MAPK) signaling in BV2 and rat primary microglial cells. These results indicated that cudratricusxanthone L (1) effectively repressed neuroinflammatory processes in BV2 and rat primary microglial cells by inhibiting NF-κB and the MAPK signaling pathway.
ARTICLE | doi:10.20944/preprints201707.0033.v1
Subject: Medicine & Pharmacology, Gastroenterology Keywords: hepatic inflammation; high-fat-cholesterol diet; hypertension; mitogen-activated protein kinase; nonalcoholic steatohepatitis; nuclear factor erythroid 2-related factor 2 pathway; nuclear factor-kappa B; spontaneously hypertensive rat; stroke-prone spontaneously hypertensive5/Dmcr; Wistar Kyoto
Online: 14 July 2017 (10:54:38 CEST)
Populations with essential hypertension have a high risk of nonalcoholic steatohepatitis (NASH). In this study, we investigated the mechanism that underlies the progression of hypertension-associated NASH by comparing differences in the development of high fat and cholesterol (HFC) diet-induced NASH among three strains of rats, i.e., two hypertensive strains comprising spontaneously hypertensive rats and the stroke-prone spontaneously hypertensive 5/Dmcr, and the original Wistar Kyoto rats as the normotensive control. We investigated histopathological changes and molecular signals related to inflammation in the liver after feeding with the HFC diet for 8 weeks. The diet induced severe lobular inflammation and fibrosis in the livers of the hypertensive rats, whereas it only caused mild steatohepatitis in the normotensive rats. Increased activation of proinflammatory signaling (transforming growth factor-β1/mitogen-activated protein kinases pathway) was observed in the hypertensive strains fed with the HFC diet. In addition, the HFC diet suppressed the nuclear factor erythroid 2-related factor 2 pathway in the hypertensive rats and led to lower increases in the hepatic expression of heme oxygenase-1, which has anti-oxidative and anti-inflammatory activities. In conclusion, these signaling pathways might play crucial roles in the development of hypertension-associated NASH.