In late December 2019, the outbreak of respiratory illness was reported in Wuhan, China. After a while, the cause of this unknown pneumonia was recognized as a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by World

Zebrafish is an important model organism in biological research. One of the least explored tissues of zebrafish is blood, because the existing methods for isolating blood from this organism are tedious and irreproducible. The small volume of blood collected by these methods also prohibits many biochemical and cytological analyses. This technical obstacle limits the utilization of zebrafish in many applications, particularly in hematological research and plasma biomarker discovery. To overcome this limitation, we have established a novel method of extracting blood from zebrafish, based on the use of low centrifugal force to collect blood from a wound. This method consistently recovers more blood than traditional methods. Gel electrophoresis and flow cytometry showed that composition of blood harvested by this method is indistinguishable from traditional methods. The increase in yield enables us to perform biochemical experiments on zebrafish blood. In particular, we have demonstrated that quantitative proteomics can be performed on plasma collected from single zebrafish. Here, we have compared, by using shotgun proteomic analysis, the plasma proteomes of adult male and female zebrafish. Twenty-seven gender-dependent plasma proteins are identified and their biochemical importance discussed. Taken together, this novel technique enables analyses that were previously difficult to perform on zebrafish blood.

Vitexin is an apigenin flavone glycoside found in food and medicinal plants. It has a variety of pharmacological effects, including antioxidant, anti‐inflammatory, anticancer, antinociceptive, and neuroprotective effects. This review study summarizes all the protective effects of vitexin as an antioxidant against reactive oxygen species, lipid peroxidation, and other oxidative damages in a variety of oxidative stress‐related diseases, including seizure, memory impairment, cerebral ischemia, neurotoxicity, myocardial and respiratory injury, and metabolic dysfunction, with possible molecular and cellular mechanisms. This review describes any activation or inhibition of the signaling pathways that depend on the antioxidant activity of vitexin. More basic research is needed on the antioxidative effects of vitexin in vivo, and carrying out clinical trials for the treatment of oxidative stress‐related diseases is also recommended.

Quercetin (3,3',4',5,7-pentahydroxyflavone) is found in vegetables and fruits. It is one of the major flavonoids that is part of human diets. Quercetin has several pharmacological effects in the nervous system as a neuroprotective agent. In this review, we summarize the research on quercetin and its role in memory in both animals and humans. Articles were chosen from the Scopus, PubMed, and Web of Science databases. In this review, we describe and summarize the importance of quercetin's presence in the body, particularly in the brain; its kinetics, including its absorption, metabolism, distribution, and excretion; its behavioral effects; and some of the possible mechanisms of action of quercetin on memory in different animal models. Several important pathways that may be involved in the processes of learning and memory, long-term potentiation, and cognition may be impaired during neurological diseases or other medical conditions. As dietary quercetin is important, provision of its best formulation for delivery to the brain as a nutraceutical and in clinical translational research for the prevention or treatment of Alzheimer's disease and other types of dementia is necessary.

One attractive quality of zebrafish as a model organism for biological research is that transparency at early developmental stages allows the optical imaging of cellular and molecular events. However, this advantage cannot be applied to adult zebrafish. In this study, we explored the use of contrast-enhanced X-ray micro-computed tomography (microCT) on adult zebrafish in which the organism was stained with iodine, a simple and economical contrasting agent, after fixation. Tomographic reconstruction of the microCT data allowed the three-dimensional (3D) volumetric analyses of individual organs in adult zebrafish. Adipose tissues showed a higher affinity to iodine and were more strongly contrasted in microCT. As traditional histological techniques often involve dehydration steps that remove tissue lipids, iodine-contrasted microCT offers a convenient method for visualizing fat deposition in fish. Utilizing this advantage, we discovered a transient accumulation of lipids around the heart after ventricular amputation, suggesting a correlation between lipid distribution and heart regeneration. Taken together, microCT is a versatile technique that enables the 3D visualization of zebrafish organs, as well as other fish models, in their anatomical context. This simple method is a valuable new addition to the arsenal of techniques available to this model organism.

It has been hypothesized that antioxidant and oxidant capacities may be related to the severity of obstructive lung impairment in patients with sulfur mustard (SM)-induced lung injuries. Our study was designed to measure the level of glutathione (GSH) and malondialdehyde (MDA) activities in patients intoxicated with SM and to evaluate the relationship between their activity and the severity of pulmonary dysfunction. A total of 250 patients with a history of exposure to a single high dose of SM gas and also 60 healthy nonsmoking individuals with no history of exposure to SM were selected. All patients underwent spirometry; based on its indices they were divided into two groups: mild (n = 140) and moderate-to-severe (n = 110) pulmonary dysfunction. Also, serum GSH and MDA concentration measurements were performed for all patients and controls. The mean GSH level in controls was 29.85 +/- 3.26 micromol/ml, which was significantly higher than in patients with mild and moderate-to-severe pulmonary dysfunction (19.02 +/- 2.36 and 17.89 +/- 2.16 micromol/ml, respectively). Also, the mean MDA level in controls was 0.69 +/- 0.09 micromol/ml, which was significantly lower than in patients with mild and moderate-to-severe pulmonary dysfunction (0.74 +/- 0.05 and 0.75 +/- 0.05 micromol/ml, respectively). There was a weak linear correlation between GSH level and some of the pulmonary function indices. On the other hand, there was no significant relationship between the MDA level and pulmonary indices. Our study confirmed important alterations in the oxidative-antioxidative system in patients suffering from SM-induced lung injuries, as shown by a decreased serum level of GSH and an increased level of MDA. Individuals with moderate-to-severe SM-induced lung injuries show a greater tendency for a decreased level of GSH and an increased level of MDA than those with mild injuries; however, there is only minimal association between pulmonary function parameters and the serum level of MDA and GSH. These findings encourage us to examine therapeutic measures to correct such imbalances in future studies.

Sexual differences have been observed in the onset and prognosis of human cardiovascular diseases, but the underlying mechanisms are not clear. Here, we found that zebrafish heart regeneration is faster in females, can be accelerated by estrogen and is suppressed by the estrogen-antagonist tamoxifen. Injuries to the zebrafish heart, but not other tissues, increased plasma estrogen levels and the expression of estrogen receptors, especially esr2a. The resulting endocrine disruption induces the expression of the female-specific protein vitellogenin in male zebrafish. Transcriptomic analyses suggested heart injuries triggered pronounced immune and inflammatory responses in females. These responses, previously shown to elicit heart regeneration, could be enhanced by estrogen treatment in males and reduced by tamoxifen in females. Furthermore, a prior exposure to estrogen preconditioned the zebrafish heart for an accelerated regeneration. Altogether, this study reveals that heart regeneration is modulated by an estrogen-inducible inflammatory response to cardiac injury. These findings elucidate a previously unknown layer of control in zebrafish heart regeneration and provide a new model system for the study of sexual differences in human cardiac repair.

Coronavirus disease 2019 (COVID‐19) is a viral disease caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). The disease was first reported in December 2019 in Wuhan, China, but now more than 200 countries have been affected and the coronavirus pandemic is still ongoing. The severity of COVID‐19 symptoms can range from mild to severe. FDA approved remdesivir as a treatment of COVID‐19 so far. Various clinical trials are underway to find an effective method to treat patients with COVID‐19. This review aimed at summarizing 219 registered clinical trials in the ClinicalTrials.gov database with possible mechanisms, and novel findings of them, and other recent publications related to COVID‐19. According to our analyses, various treatment approaches and drugs are being investigated to find an effective drug to cure COVID‐19 and among all strategies, three important mechanisms are suggested to be important against COVID‐19 including antiviral, anti‐inflammatory, and immunomodulatory properties. Our review can help future studies get on the way to finding an effective drug for COVID‐19 treatment by providing ideas for similar researches.