Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) gains access to host cells by attaching to angiotensin-converting enzyme 2 (ACE2). Vitamin D (VitD) can upregulate ACE2 and has an antagonistic effect on Renin, which exerts a vasodilatation and anti-inflammatory effect against coronavirus disease (COVID-19). However, it may also facilitate viral entry by increasing ACE2 as the main SARS-CoV-2 receptor and mediates ROS production through NADPH oxidase, as a double-edged sword effect. Lung function and the immune system are also influenced by VitD through several mechanisms, including increased natural antibiotics (Defensin and Cathelicidin) and upregulated transforming growth factor-β. A higher IgA, Th2/Th1 ratio, and T-regulatory cells are attributable to VitD effects on the immune cells, while these changes may also be a double-edged sword in COVID-19. Although VitD supplementation might be highly recommended in COVID-19, the administration's dosage and route could be challenging. Furthermore, this issue has not been mentioned in various studies so far. So, the report aimed to explain the current challenges with the application of VitD in COVID-19. 相似文献
Cluster Computing - Internet of things has become an essential principle of human life with the widespread acceptance of intelligent environments, where everyday objects can communicate through the... 相似文献
In vitro experiments show that the cells possibly responsible for radiation-induced acute myeloid leukemia (rAML) exhibit low-dose hyper-radiosensitivity (HRS). In these cells, HRS is responsible for excess cell killing at low doses. Besides the endpoint of cell killing, HRS has also been shown to stimulate the low-dose formation of chromosomal aberrations such as deletions. Although HRS has been investigated extensively, little is known about the possible effect of HRS on low-dose cancer risk. In CBA mice, rAML can largely be explained in terms of a radiation-induced Sfpi1 deletion and a point mutation in the remaining Sfpi1 gene copy. The aim of this paper is to present and quantify possible mechanisms through which HRS may influence low-dose rAML incidence in CBA mice. To accomplish this, a mechanistic rAML CBA mouse model was developed to study HRS-dependent AML onset after low-dose photon irradiation. The rAML incidence was computed under the assumptions that target cells: (1) do not exhibit HRS; (2) HRS only stimulates cell killing; or (3) HRS stimulates cell killing and the formation of the Sfpi1 deletion. In absence of HRS (control), the rAML dose-response curve can be approximated with a linear-quadratic function of the absorbed dose. Compared to the control, the assumption that HRS stimulates cell killing lowered the rAML incidence, whereas increased incidence was observed at low doses if HRS additionally stimulates the induction of the Sfpi1 deletion. In conclusion, cellular HRS affects the number of surviving pre-leukemic cells with an Sfpi1 deletion which, depending on the HRS assumption, directly translates to a lower/higher probability of developing rAML. Low-dose HRS may affect cancer risk in general by altering the probability that certain mutations occur/persist.
The aim of this study was to microencapsulate caffeine by the emulsion technique, trying to control its release from a medicated chewing gum. Three formulations were prepared using alginate, alginate-starch, and alginate-starch with chitosan coating as the wall materials. These microcapsules were characterized with regard to the morphology studied by using an optical microscope and scanning electron microscopy (SEM), particle size, and encapsulation efficiency. The microcapsules were then incorporated into the chewing gums. The chewing gums were characterized by thermal behavior (by differential scanning calorimetry [DSC]), texture profile analysis [TPA], and sensory evaluation. Furthermore, the release of caffeine from the chewing gum was studied in vitro using the masticatory simulator and in vivo by a chew-out study. The microcapsules revealed a spherical form and high encapsulation efficiency, representing the success of the technique. The outcomes indicated that it is possible to encapsulate caffeine with the techniques employed and the microcapsules prolonged the release of caffeine throughout mastication. The chewing gum containing alginate-starch with chitosan-coated microcapsules showed the great potential of the microcapsule in controlling the release of the caffeine from the chewing gum, thereby delaying its bitterness. 相似文献
In the last decade, significant progress has been made in expanding the scope and depth of publicly available immunological
databases and online analysis resources, which have become an integral part of the repertoire of tools available to the scientific
community for basic and applied research. Herein, we present a general overview of different resources and databases currently
available. Because of our association with the Immune Epitope Database and Analysis Resource, this resource is reviewed in
more detail. Our review includes aspects such as the development of formal ontologies and the type and breadth of analytical
tools available to predict epitopes and analyze immune epitope data. A common feature of immunological databases is the requirement
to host large amounts of data extracted from disparate sources. Accordingly, we discuss and review processes to curate the
immunological literature, as well as examples of how the curated data can be used to generate a meta-analysis of the epitope
knowledge currently available for diseases of worldwide concern, such as influenza and malaria. Finally, we review the impact
of immunological databases, by analyzing their usage and citations, and by categorizing the type of citations. Taken together,
the results highlight the growing impact and utility of immunological databases for the scientific community. 相似文献