Gastrointestinal Disease and COVID-19: A Review of Current Evidence.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has had an unprecedented and catastrophic impact on humanity and continues to progress. In addition to typical respiratory symptoms such as fever, cough, and dyspnea, a large percentage of COVID-19 patients experience gastrointestinal (GI) complaints, with the most common symptoms being diarrhea, nausea, vomiting, and abdominal discomfort. SUMMARY: We comprehensively summarize the latest knowledge of the adverse effects of COVID-19 and therapeutic drugs on the GI system, as well as related disease pathogenesis, and then provide a discussion focusing on the management and vaccination of patients who have inflammatory bowel disease (IBD) and GI cancer. The virus can affect the digestive system via binding to ACE2 receptors and subsequent gut microbiome dysbiosis. Through a variety of molecular pathways and mechanisms, numerous drugs for the treatment of COVID-19 could interfere with GI function and lead to multiple clinical manifestations, which may further intensify the risk and severity of GI symptoms of COVID-19 infection, such as nausea, vomiting, gastroparesis, and gastric ulcers. KEY MESSAGES: We should monitor GI manifestations closely while managing COVID-19 patients and take timely measures to reduce the incidence of SARS-CoV-2 infections in GI cancer patients. IBD patients should receive vaccination timely, but corticosteroid use should be minimized when they are vaccinated. Simultaneously, for persons with IBD who have known or suspected COVID-19, immunosuppressive agents, especially thiopurines, should be avoided/minimized if possible.

Finite element method-based study for spinal vibration characteristics of the scoliosis and kyphosis lumbar spine to whole-body vibration under a compressive follower preload.

PURPOSE: To analyze the dynamic response of the lumbosacral vertebrae structure of a scoliosis spine and a kyphosis spine under whole-body vibration. METHODS: Typical Lenke4 (kyphosis) and Lenke3 (scoliosis) spinal columns were used as research objects. A finite element model of the lumbosacral vertebrae segment was established and validated based on CT scanning images. Modal, harmonic response, and transient dynamic analyses were performed on the lumbar-sacral scoliosis model using the finite element software abaqus. RESULTS: The first four resonance frequencies of kyphosis spine extracted from modal analysis were 0.86, 1.45, 8.51, and 55.71 Hz. The first four resonance frequencies of scoliosis spine extracted from modal analysis were 0.76, 1.45, 10.51, and 63.82 Hz. The scoliosis spine had the maximum resonance amplitude in the transverse direction, while the kyphosis spine had the maximum resonance amplitude in the anteroposterior direction. The dynamic response in transient analysis exhibited periodic response over time at all levels. CONCLUSION: The scoliosis and kyphosis deformity of the spine significantly complicates the vibration response in the scoliosis and kyphosis areas at the top of the spine. Scoliosis and kyphosis patients are more likely to experience vibrational spinal diseases than healthy people. Besides, applying vertical cyclic loads on a malformed spine may cause further rotation of scoliosis and kyphosis deformities.

Evaluation of phytohormone facilitation in microalgal biomass production using mathematical modeling.

How to improve the growth efficiency of microalgae is the bottleneck of microalgae large-scale application. The addition of trace substances can promote the growth of microalgae, but there is no suitable model that can be used to predict the effects of trace substance concentrations on the growth of microalgae. In the present study, a mathematical model based on hormesis is proposed to describe the effects produced by trace substances on the biomass of microalgae and applied to assess the dose-response of four phytohormones on Scenedesmus sp. LX1 with a high coefficient of determination (R2 ≥ 0.90). Several new mathematical parameters, such as starting effective dose (SD), inflection point dose (PD), concentration for 0 % of maximal effect, end effective dose (ED), maximum stimulatory effect (MSE), and maximum inhibitory effect (MIE), were extracted and useful to help researchers in applying trace substances to assist in the production of microalgal biomass for data reference and prediction. In concrete terms, the above model parameters can be well applied to screen the trace substances, dominant algal species and determine the concentration range. This study provides valuable insights into the potential of using phytohormones to enhance the biomass production of microalgae and offers a new approach to optimizing the culture of microalgae.

Potential Adverse Effects of Dexamethasone Therapy on COVID-19 Patients: Review and Recommendations.

In the context of the coronavirus disease 2019 (COVID-19) pandemic, the global healthcare community has raced to find effective therapeutic agents against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To date, dexamethasone is the first and an important therapeutic to significantly reduce the risk of death in COVID-19 patients with severe disease. Due to powerful anti-inflammatory and immunosuppressive effects, dexamethasone could attenuate SARS-CoV-2-induced uncontrolled cytokine storm, severe acute respiratory distress syndrome and lung injury. Nevertheless, dexamethasone treatment is a double-edged sword, as numerous studies have revealed that it has significant adverse impacts later in life. In this article, we reviewed the literature regarding the adverse effects of dexamethasone administration on different organ systems as well as related disease pathogenesis in an attempt to clarify the potential harms that may arise in COVID-19 patients receiving dexamethasone treatment. Overall, taking the threat of COVID-19 pandemic into account, we think it is necessary to apply dexamethasone as a pharmaceutical therapy in critical patients. However, its adverse side effects cannot be ignored. Our review will help medical professionals in the prognosis and follow-up of patients treated with dexamethasone. In addition, given that a considerable amount of uncertainty, confusion and even controversy still exist, further studies and more clinical trials are urgently needed to improve our understanding of the parameters and the effects of dexamethasone on patients with SARS-CoV-2 infection.