Search Results (1,670)

Background: The continuous evolution of SARS-CoV-2 and the emergence of novel variants with numerous mutations have heightened concerns surrounding the possibility of cross-species transmission and the establishment of natural animal reservoirs for the virus, but the host range of emerging SARS-CoV-2 variants has not been fully explored yet. Methods: We employed an in vitro model comprising VSV∆G* pseudotyped viruses bearing SARS-CoV-2 spike proteins to explore the plausible host range of SARS-CoV-2 emerging variants. Results: The overall host tropism of emerging SARS-CoV-2 variants are consistent with that of the SARS-CoV-2 wuhan-hu-1 strain with minor difference. Pseudotyped viruses bearing spike protein from RaTG13 and RmYN02 can enter cell cultures from a broad range of mammalian species, revealing that mink and hamsters may act as potential intermediate hosts. We further investigated 95 potential site-specific mutations in the SARS-CoV-2 spike protein that could impact viral infectivity across different species. The results showed that 13 of these mutations notably increased the transduction rates by more than two-fold when compared to the wild-type spike protein. Further examination of these 13 mutations within cell cultures from 31 different species revealed heightened sensitivity in cells derived from palm civets, minks, and Chinese horseshoe bats to the VSV∆G*-SARS2-S mutants. Specific mutations, such as L24F, R158G, and L212I, were seen to significantly enhance the capacity for SARS-CoV-2 of cross-species transmission. Conclusions: This study offers critical insights for the ongoing surveillance and monitoring efforts of SARS-CoV-2 evolution, emphasizing the need for the vigilant monitoring of specific mutations in both human and animal populations. Full article

Mercury (Hg) has been extensively studied due to its impact on the environment and health, but its effects on wild mammal populations are still poorly known. Therefore, the use of biomonitors has gained importance. Our objective was to report and compare, for the first time, the amount of mercury in small mammals belonging to three trophic guilds and to provide an initial toxicology perspective in the Mezquital Valley, a critically polluted area of Central Mexico. We quantified total Hg from the hair and liver of a nectarivorous bat (Leptonycteris yerbabuenae), an insectivorous bat (Corynorhinus townsendii) and a granivorous mouse (Peromyscus melanophrys) using atomic absorption spectrometry during the dry and rainy seasons. We compared the mercury concentrations between seasons, species and matrices. In all species, the average mercury content was higher in hair than liver, and there was no correlation between matrices. There was no difference in mercury content among species. Hg concentrations in the livers of P. melanophrys and C. townsendii were lower during the dry season than the rainy season, suggesting a seasonal decline in mercury availability. All of the values detected were below the neurotoxicity threshold reported in small mammals (10 ppm); however, we propose constant monitoring of Hg in their environment and confirm the utility of these species as biomonitors. Full article

Ulva prolifera, known as Aonori in Japan, is an edible alga species that is mass-cultivated in Japan. Supplementation with Aonori-derived biomaterials has been reported to enhance metabolic health in previous studies. This was an experimental study that evaluated the metabolic health effects of NBF2, a formula made of algal and junos Tanaka citrus-derived biomaterials, on obesity and type 2 diabetes (T2DM). We used 18 obese and hyperglycemic Otsuka Long-Evans Tokushima Fatty (OLETF) rats that were assigned randomly to three groups of six animals: a high-dose NBF2 drink (20 mg/kg) group, a low-dose (10 mg/kg) NBF2 drink group and the control group that received 2 mL of tap water daily for a total of six weeks. We also used eight LETO rats as the normal control group. In addition to the glucose tolerance test (OGTT), ELISA and real-time PCR assays were performed. High-dose and lowdose NBF2 improved insulin sensitivity, as well as glycemic and lipid profiles, as compared with control rats. The OGTT showed that both NBF2 groups and LETO rats had normalized glycemia by the 90-min time-point. NBF2 up-regulated PPARα/γ-mRNA and Sirt2-mRNA gene expressions in BAT and improved the blood pressure profile. These findings suggest that the NBF2 formula, which activates PPAR-α/γ mRNA and Sirt2-mRNA, may reverse dyslipidemia and hyperglycemia in T2DM. Full article

L-ascorbic acid (AsA, vitamin C) plays a vital role in preventing various diseases, particularly scurvy. AsA is known for its antioxidant properties, which help protect against reactive oxygen species generated from metabolic activities; however, at high doses, it may exhibit pro-oxidative effects. The final step in AsA biosynthesis is catalyzed by L-gulono-γ-lactone oxidase (GULO). This enzyme is present in many organisms, but some animals, including humans, guinea pigs, bats, and other primates, are unable to synthesize AsA due to the absence of a functional GULO gene. The GULO enzyme belongs to the family of aldonolactone oxidoreductases (AlORs) and contains two conserved domains, an N-terminal FAD-binding region and a C-terminal HWXK motif capable of binding the flavin cofactor. In this review, we explore AsA production, the biosynthetic pathways of AsA, and the localization of GULO-like enzymes in both animal and plant cells. Additionally, we compare the amino acid sequences of AlORs across different species and summarize the findings related to their enzymatic activity. Interestingly, a recombinant C-terminal rat GULO (the cytoplasmic domain of the rat GULO expressed in Escherichia coli) demonstrated enzymatic activity. This suggests that the binding of the flavin cofactor to the HWXK motif at the C-terminus is sufficient for the formation of the enzyme’s active site. Another enzyme, GULLO7 from Arabidopsis thaliana, also lacks the N-terminal FAD-binding domain and is strongly expressed in mature pollen, although its activity has not been specifically measured. Full article

Background and Objectives: Allergy to dust mites (HDMs) plays an important role in atopic dermatitis (AD). However, the role of this allergy in other dermatoses is little known. The aim of this study was to assess hypersensitivity to HDMs in patients with AD or hand disease using the basophil activation test. Material and Methods: A total of 52 patients with AD, 57 with hand eczema disease, and 68 healthy volunteers qualified for this study. Diagnosis was based on the Hanifin and Rajka criteria, dermatological assessment, and exclusion of other dermatoses. The participants underwent skin prick tests (SPTs), a basophil activation test (BAT) with D. pteronyssinus allergen extract, and the concentration of specific IgE (sIgE) for the same allergen in blood serum was determined. Results: Positive results in all tests (SPT, sIgE, and BAT) were obtained (24 (46.2%) patients with AD, 9 (15.8%) with hand disease, and none in the control group for p < 0.05). The results of the SPT, sIgE, and BAT correlated with each other in the AD and hand eczema groups (Spearmen correlation test, r = 0.72 or 0.85, p < 0.05). However, the BAT was positive more often than the SPT and sIgE for D. pteronyssinus. Conclusions: House dust mite hypersensitivity is common in patients with AD and eczema. The BAT may be more sensitive for assessing sensitization to house dust mites, especially in patients with hand eczema. Full article

A novel jeilongvirus was identified through next-generation sequencing in cell cultures inoculated with spleen and kidney extracts. The spleen and kidney were obtained from a Peromyscus gossypinus rodent (cotton mouse) found dead in the city of Gainesville, in North-Central Florida, USA. Jeilongviruses are paramyxoviruses of the subfamily Orthoparamyxovirinae that have been found in bats, cats, and rodents. We designated the virus we discovered as Gainesville rodent jeilong virus 1 (GRJV1). Preliminary results indicate that GRJV1 can complete its life cycle in various human, non-human primate, and rodent cell lines, suggesting that the virus has a generalist nature with the potential for a spillover event. The early detection of endemic viruses circulating within hosts in North-Central Florida can significantly enhance surveillance efforts, thereby bolstering our ability to monitor and respond to potential outbreaks effectively. Full article

In this article, the development of a bat-ray-inspired underwater vehicle is presented; although the propulsion of the vehicle is based on traditional thrusters, the shape of the ray’s fins was used as a model to design the body of the vehicle; this architecture allows the independent control of the forward velocity and the full attitude of the vehicle using only two thrusters and two articulated fins. The compact design of the robot, along with the high dexterity of the architecture, allows the vehicle to submerge and emerge vertically as well as navigate horizontally. The mathematical model of the proposed vehicle, including dynamics and propulsion system, is presented and validated using numerical simulations. Finally, experimental tests are presented to demonstrate the capabilities of the proposed design. Full article

Over the past three years, new SARS-CoV-2 variants have continuously emerged, evolving to a point where an immune response against the original vaccine no longer provided optimal protection against these new strains. During this time, high-throughput neutralization assays based on pseudoviruses have become a valuable tool for assessing the efficacy of new vaccines, screening updated vaccine candidates against emerging variants, and testing the efficacy of new therapeutics such as monoclonal antibodies. Lentiviral vectors derived from HIV-1 are popular for developing pseudo and chimeric viruses due to their ease of use, stability, and long-term transgene expression. However, the HIV-based platform has lower transduction rates for pseudotyping coronavirus spike proteins than other pseudovirus platforms, necessitating more optimized methods. As the SARS-CoV-2 virus evolved, we produced over 18 variants of the spike protein for pseudotyping with an HIV-based vector, optimizing experimental parameters for their production and transduction. In this article, we present key parameters that were assessed to improve such technology, including (a) the timing and method of collection of pseudovirus supernatant; (b) the timing of host cell transduction; (c) cell culture media replenishment after pseudovirus adsorption; and (d) the centrifugation (spinoculation) parameters of the host cell+ pseudovirus mix, towards improved transduction. Additionally, we found that, for some pseudoviruses, the addition of a cationic polymer (polybrene) to the culture medium improved the transduction process. These findings were applicable across variant spike pseudoviruses that include not only SARS-CoV-2 variants, but also SARS, MERS, Alpha Coronavirus (NL-63), and bat-like coronaviruses. In summary, we present improvements in transduction efficiency, which can broaden the dynamic range of the pseudovirus titration and neutralization assays. Full article

The aim of this study was to optimize a basophil activation test in the detection of allergy to the house dust mite Dermatophagoides pteronyssinus in children with allergic respiratory diseases. This study involved 32 cases, 13 girls and 19 boys aged 4–17 years, with perennial asthma or allergic rhinitis caused by D. pteronyssinus. The control group consisted of 13 girls and 19 boys aged 4–17 years with seasonal allergic asthma or rhinitis provoked by Timothy or birch pollen. House dust mite (HDM) allergy was excluded in the controls based on their medical history, skin prick test (SPT) results and sIgE determination. In all patients, a basophil activation test (BAT) was performed with five dilutions of D. pteronyssinus allergen (the dilution series ranged from 22.5 to 0.00225 ng/mL). The results were analyzed by using the receiver operating characteristics (ROC) to determine the optimal allergen concentrations, outcome measures and cut-off points that would differentiate most accurately between HDM-allergic and non-allergic patients. As a “gold standard”, criteria for allergen-specific immunotherapy with D. pteronyssinus or respective pollens were applied by an experienced pediatric allergist following the guidelines of the European Academy of Allergy and Clinical Immunology. The highest diagnostic efficiency was yielded by the protocol assuming a cut-off value of 9.76% activated basophils after activation with a single allergen concentration of 2.25 ng/mL (sensitivity 90.6%, specificity 100%). This protocol yielded 3 (4.7%) misclassifications, all false negative, when compared with the “gold standard”. There was a strong correlation with the BAT results at 22.5, 2.25 and 0.225 ng/mL (respectively r = 0.90 and r = 0.78, p < 0.001), as well as between the BAT at 2.25 ng/mL and SPT (r = 0.82, p < 0.001) and between the SPT and sIgE levels (r = 0.78, p < 0.001). High cross-reactivity between D. pteronyssinus and D. farinae was confirmed based on the BAT at 22.5 ng/mL (r = 0.82, p < 0.001). In conclusion, the BAT showed very good concordance with the result of a meticulous process of decision-making that combined validated allergy tests (SPT, sIgE) with expert guidelines, specialist knowledge and experience. Facing the risk of the incorrect qualification of patients for costly, long-lasting and potentially risky allergen-specific immunotherapy, the inclusion of a basophil activation test into diagnostic process seems fully justified. Full article

The diagnosis of drug-induced anaphylaxis (DIA) is a serious health problem. The Basophil activation test (BAT) is considered a specific in vitro provocation, and compared to in vivo provocation, it is more convenient, cheaper, and safer for the patient. This study aimed to evaluate the usefulness of the BAT in the diagnosis of DIA. This study included 150 patients referred to a reference allergy clinic with suspected drug allergies. All patients underwent a detailed clinical evaluation supplemented with the BAT. Positive BAT results were obtained in two out of 21 patients who were to receive the COVID-19 vaccine. The sensitivity and specificity of the BAT were 40% and 75% for the COVID-19 vaccine, 67% and 58% for DMG PEG 2000, and 100% and 75% for PEG 4000, respectively. Nine out of 34 patients with suspected antibiotic allergies had positive BAT results with 14 different antibiotics. Positive BAT results were also obtained with NSAIDs in two patients and with local anesthetics in three patients. The confirmation of allergy by the BAT improves the safety profile of the diagnostic work-up as it may defer the need for drug provocation, preventing potential anaphylactic reactions. Full article

Modern power systems are growing in complexity due to the installation of large generators, long transmission lines, the addition of inertialess renewable energy resources (RESs) with zero inertia, etc., which can all severely degrade the system frequency stability. This can lead to under-/over-frequency load shedding, damage to turbine blades, and affect frequency-sensitive loads. In this study, we propose a methodology to improve the two critical frequency stability indices, i.e., the frequency nadir and the rate of change of frequency (RoCoF), by formulating an optimization problem. The size and placement location of battery energy storage systems (BESSs) are considered to be the constraints for the proposed optimization problem. Thereafter, the optimization problem is solved using the three metaheuristic optimization algorithms: the particle swarm optimization, firefly, and bat algorithm. The best performing algorithm is then selected to find the optimal sizing and placement location of the BESSs. The analyses are all performed on the IEEE 9-bus and IEEE 39-bus test systems. Several scenarios which consider multiple generator outages, increased/decreased loading conditions, and the addition of RESs are also considered for both test systems in this study. The obtained results show that under all scenarios, the proposed method can enhance system frequency compared to the existing method and without BESSs. The proposed method can be easily upscaled for a larger electrical network for obtaining the optimized BESS size and location for the improvement of the system frequency stability. Full article

Circadian rhythms are found in a wide range of organisms and have garnered significant research interest in the field of chronobiology. Under normal circadian function, metabolic regulation is temporally coordinated across tissues and behaviors within a 24 h period. Metabolites, as the closest molecular regulation to physiological phenotype, have dynamic patterns and their relationship with circadian regulation remains to be fully elucidated. In this study, untargeted brain metabolomics was employed to investigate the daily rhythms of metabolites at four time points corresponding to four typical physiological states in Vespertilio sinensis. Key brain metabolites and associated physiological processes active at different time points were detected, with 154 metabolites identified as rhythmic. Analyses of both metabolomics and transcriptomics revealed that several important physiological processes, including the pentose phosphate pathway and oxidative phosphorylation, play key roles in regulating rhythmic physiology, particularly in hunting and flying behaviors. This study represents the first exploration of daily metabolic dynamics in the bat brain, providing insights into the complex regulatory network of circadian rhythms in mammals at a metabolic level. These findings serve as a valuable reference for future studies on circadian rhythms in nocturnal mammals. Full article

RaTG13 is phylogenomically the closest related coronavirus to SARS-CoV-2; consequently, understanding the provenance of this high-value genome sequence is important in understanding the origin of SARS-CoV-2. While RaTG13 was described as being generated from a Rhinolophus affinis fecal swab obtained from a mine in Mojiang, Yunnan, numerous investigators have pointed out that this is inconsistent with the low proportion of bacterial reads in the sequencing dataset. Metagenomic analysis confirms that only 10.3% of small-subunit (SSU) rRNA sequences in the dataset are bacterial, which is inconsistent with a fecal sample. In addition, the bacterial taxa present in the sample are shown to be inconsistent with fecal material. The assembly of mitochondrial SSU rRNA sequences in the dataset produces a sequence 98.7% identical to R. affinis mitochondrial SSU rRNA, indicating that the sample was generated from R. affinis or a closely related species. In addition, 87.5% of the reads in the dataset map to the Rhinolophus ferrumequinum genome, and 62.2% of these map to protein-coding genes, indicating that the dataset represents a Rhinolophus sp. transcriptome rather than a fecal swab sample. Differential gene expression analysis reveals that the pattern of expressed genes in the RaTG13 dataset is similar to that of RaTG15, which was also collected from the Mojiang mine. GO enrichment analysis reveals the overexpression of spermatogenesis- and olfaction-related genes in both datasets. This observation is consistent with a mating plug found in female Rhinolophid bats and suggests that RaTG13 was mis-sampled from such a plug. A validated natural provenance of the RaTG13 dataset throws into relief the unusual features of the SARS-CoV-2 genome. Full article

Dietary changes expose consumers to risks from Anisakis larvae in seafood, leading to parasitic diseases and allergies. Anisakis is recognized by EFSA as a significant hazard, with potential oncogenic implications. Diagnostic advancements, like the Basophil Activation Test (BAT), enhance sensitivity and accuracy in identifying Anisakis sensitization, complementing traditional IgE tests. We conducted a cross-sectional study on patients with allergic symptoms from April 2021 to April 2023 at two outpatient clinics in western Sicily. Our goal was to assess the prevalence of Anisakis-related allergies and to identify risk profiles using specific Anisakis IgE and the BAT, especially in regions with high raw fish consumption. The study evaluated specific Anisakis IgE as a screening tool for Anisakis sensitization, using questionnaires, blood samples, and immuno-allergology analyses. Anisakis-specific IgE values were compared with the BAT results, with statistical analyses including Fisher’s exact test and logistic regression. The results showed an 18.5% seroprevalence of Anisakis IgE, while the BAT as a second-level test showed 4.63%, indicating the BAT’s superior specificity and accuracy. The study highlighted the importance of the BAT in diagnosing Anisakis sensitization, especially in cases of cross-reactivity with Ascaris and tropomyosin. The findings confirm the BAT’s exceptional specificity in identifying Anisakis sensitization and support using Anisakis-specific IgE for population-based risk profiling. The BAT can effectively serve as a confirmatory test. Full article

Mites from the Demodecidae and Psorergatidae can optimally use mammalian hosts by inhabiting a number of different microhabitats in their skin. Hence, in individual hosts, several species of parasites from these groups have been described in different microhabitats. There are few data on their co-occurrence either at the host species level or at the host individual level. Most research has addressed the co-occurrence of Demodecidae in carnivorans, ungulates, soricomorphs, and rodents, while the co-occurrence of both families was found in bats. The present study examines the possibility of their co-occurrence in a Eurasian rodent—Apodemus flavicollis. It is a suitable model for such analyses, because representatives of both families have been demonstrated here so far, and our findings extend the list of specific Demodecidae in A. flavicollis with two new species: Demodex tenuis sp. nov. from the lip region and D. mediocris sp. nov. from the chin region. The study also includes the first record of Psorergates muricola in this host, which occurred in the genital–anal region. Therefore, the findings confirm the possibility that different Demodecidae and Psorergatidae species can co-occur in the same host in different body regions. This paper also includes a checklist of Demodecidae and Psorergatidae in rodents around the world. Full article