A case report of a teenager with severe hand, foot, and mouth disease with brainstem encephalitis caused by enterovirus 71

Metformin inhibits EV71‑induced pyroptosis by upregulating DEP domain‑containing mTOR‑interacting protein

Enterovirus 71 (EV71) infection is one of the main causes of severe hand, foot and mouth disease (HFMD), which is usually accompanied by a marked inflammatory response. The excessive inflammatory response has been implicated to serve an important role in EV71-caused HFMD. Pyroptosis is a type of inflammatory programmed cell death. Therefore, a novel treatment strategy against EV71 infection could aim to alleviate the inflammatory response through inhibition of EV71-induced pyroptosis. The present study revealed that metformin had this therapeutic potential. A cell model of EV71 infection was established, cell viability was measured by CCK8 assay, cell damage was measured by LDH release kit, and the dead and dying cells were excluded by propidium iodide staining. The intracellular levels of DEP domain-containing mTOR interacting protein (DEPTOR) and pyroptosis-associated molecules were measured by western blot analysis, the NLRP3 expression was assessed by immunofluorescence labeling, and virus titers in cell culture supernatants were determined by a cell culture infectious dose 50 assay. The results demonstrated that EV71 infection could induce pyroptosis in a time- and dose-dependent manner, and metformin could inhibit EV71-induced pyroptosis. The mechanism of metformin inhibiting EV71-induced pyroptosis was explored next. Subsequent experiments indicated that metformin could increase the levels of DEPTOR, which were decreased by EV71. Finally, overexpression of DEPTOR in cells could reduce EV71-induced pyroptosis. Overall, the present study demonstrated that metformin could exert a novel pharmacodynamic anti-pyroptosis effect in the treatment of EV71 infection by upregulating DEPTOR expression.

Recent advances in enterovirus A71 pathogenesis: a focus on fatal human enterovirus A71 infection

Enterovirus A71 (EV-A71) is one of the major pathogens responsible for hand, foot, and mouth disease (HFMD). Many HFMD outbreaks have been reported throughout the world in the past decades. Compared with other viruses, EV-A71 infection is more frequently associated with severe neurological complications and even death in children. EV-A71 can also infect adults and cause severe complications and death, although such cases are very uncommon. Although fatal cases of EV-A71 infection have been reported, the underlying mechanisms of EV-A71 infection, especially the mode of viral spread into the central nervous system (CNS) and mechanisms of pulmonary edema, which is considered to be the direct cause of death, have not yet been fully clarified, and more studies are needed. Here, we first summarize the pathological findings in various systems of patients with fatal EV-A71 infections, focussing in detail on gross changes, histopathological examination, tissue distribution of viral antigens and nucleic acids, systemic inflammatory cell infiltration, and tissue distribution of viral receptors and their co-localization with viral antigens. We then present our conclusions about viral dissemination, neuropathogenesis, and the mechanism of pulmonary edema in EV-A71 infection, based on pathological findings.

Hand, Foot, and Mouth Disease: A Narrative Review

BACKGROUND

Hand, foot, and mouth disease is a common viral disease in childhood. Because the disease has the potential to reach epidemic levels and mortality is high in some countries, early recognition of this disease is of paramount importance.

OBJECTIVE

This purpose of this article is to familiarize pediatricians with the clinical manifestations and management of hand, foot, and mouth disease.

METHODS

A search was conducted in February 2022 in PubMed Clinical Queries using the key term "hand, foot, and mouth disease". The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in English were included in this review.

RESULTS

Hand, foot, and mouth disease is characterized by a painful oral enanthem and asymptomatic exanthem on the palms and soles. Children younger than 5 years are most commonly affected. Hand, foot, and mouth disease caused by enterovirus A71 is more severe and has a higher rate of complications than that attributed to other viruses such as coxsackievirus A16. Circulatory failure secondary to myocardial impairment and neurogenic pulmonary edema secondary to brainstem damage are the main causes of death. Fortunately, the disease is usually benign and resolves in 7 to10 days without sequelae. Given the self-limited nature of most cases, treatment is mainly symptomatic and supportive. Intravenous immunoglobulin should be considered for the treatment of severe/complicated hand, foot, and mouth disease and has been recommended by several national and international guideline committees. Currently, there are no specific antiviral agents approved for the treatment of the disease. Drugs such as ribavirin, suramin, mulberroside C, aminothiazole analogs, and sertraline have emerged as potential candidates for the treatment of hand, foot, and mouth disease. Vaccination of susceptible individuals in high-risk areas and good personal hygiene are important preventative measures to combat the disease.

CONCLUSION

Familiarity of the disease including its atypical manifestations is crucial so that a correct diagnosis can be made, and appropriate treatment initiated. A timely diagnosis can help avoid contact with the affected individual and decrease the risk of an outbreak.

Effective Use of Student-Created Case Studies as Assessment in an Undergraduate Neuroscience Course

Case studies and student-led learning activities are both effective active learning methods for increasing student engagement, promoting student learning, and improving student performance. Here, we describe combining these instructional methods to use student-created case studies as assessment for an online neurovirology module in a neuroanatomy and physiology course. First, students learned about neurovirology in a flipped classroom format using free, open-access virology resources. Then, students used iterative writing practices to write an interrupted case study incorporating a patient narrative and primary literature data on the neurovirulent virus of their choice, which was graded as a writing assessment. Finally, students exchanged case studies with their peers, and both taught and completed the case studies as low-stakes assessment. Student performance and evaluations support the efficacy of case studies as assessment, where iterative writing improved student performance, and students reported increased knowledge and confidence in the corresponding learning objectives. Overall, we believe that using student-created case studies as assessment is a valuable, student-led extension of effective case study pedagogy, and has wide applicability to a variety of undergraduate courses.

Analysis of the Effect of Incentive Nursing Intervention in Children with Severe Viral Encephalitis and Myocarditis during Rehabilitation Based on Diffusion Weighted MRI

Background

Severe viral encephalitis in children causes a viral infection that damages their central nervous system. This situation arises the mental abnormalities, sudden rise in body temperature, disturbance of consciousness, and so forth in children, which can be life-threatening.

Objective

This work aimed at exploring the effect of diffusion weighted MRI on children with severe viral encephalitis and myocarditis.

Methods

This work presents a diffusion weighted MRI scanning method that involves scanning through a serial imaging device, axial scanning, and sagittal and coronal scanning. 60 children with severe viral encephalitis and myocarditis who admitted to Brain Hospital of Hunan Province from April 2017 to May 2020 were deemed as research subjects. All the children underwent CT and MRI examination, blood routine examination, and cerebrospinal fluid examination after admission. This work uses the random number table method to classify the subjects into control group and observation group, each consisting of 30 cases. Children in the control group were provided with the routine nursing intervention, whereas children in the observation group were subjected to incentive nursing intervention. The baseline data, ECG monitoring indicators, body abnormalities, and clinical symptom relief time of the two groups of children were compared and the results of diffusion weighted MRI scans were analyzed and the ADC values were counted.

Results

The two groups of children were compared on the basis of baseline data, and the variation was not statistically substantial (P > 0.05). The cases of children in the control group had higher heart rate and respiration, and physical dysfunction, language dysfunction, unconsciousness, and nervous dysfunction were more than those in the observation group. However, the cases of blood oxygen saturation were less than those of the observation group. After nursing intervention done for the control group, remission time of clinical symptoms such as convulsion, physical dysfunction, unconsciousness, and nerve dysfunction was longer relative to the observation group (all P < 0.05 are considered).

Conclusion

The diffusion weighted MRI had diagnostic significance for severe viral encephalitis and myocarditis. For children with severe viral encephalitis and myocarditis, clinical incentive nursing intervention was particularly imperative. It can not only help children to relieve symptoms and control the deterioration of the disease in a short time but also help improve the quality of life of the children and the confidence of family members to cope with the disease.

TAR DNA-Binding Protein 43 is Cleaved by the Protease 3C of Enterovirus A71

Enterovirus A71 (EV-A71) is one of the etiological pathogens leading to hand, foot, and mouth disease (HFMD), which can cause severe neurological complications. The neuropathogenesis of EV-A71 infection is not well understood. The mislocalization and aggregation of TAR DNA-binding protein 43 (TDP-43) is the pathological hallmark of amyotrophic lateral sclerosis (ALS). However, whether TDP-43 was impacted by EV-A71 infection is unknown. This study demonstrated that TDP-43 was cleaved during EV-A71 infection. The cleavage of TDP-43 requires EV-A71 replication rather than the activated caspases due to viral infection. TDP-43 is cleaved by viral protease 3C between the residues 331Q and 332S, while mutated TDP-43 (Q331A) was not cleaved. In addition, mutated 3C which lacks the protease activity failed to induce TDP-43 cleavage. We also found that TDP-43 was translocated from the nucleus to the cytoplasm, and the mislocalization of TDP-43 was induced by viral protease 2A rather than 3C. Taken together, we demonstrated that TDP-43 was cleaved by viral protease and translocated to the cytoplasm during EV-A71 infection, implicating the possible involvement of TDP-43 in the pathogenesis of EV-A71infection.

Innate Viral Sensor MDA5 and Coxsackievirus Interplay in Type 1 Diabetes Development

Type 1 diabetes (T1D) is a polygenic autoimmune disease characterized by immune-mediated destruction of insulin-producing β-cells. The concordance rate for T1D in monozygotic twins is ≈30-50%, indicating that environmental factors also play a role in T1D development. Previous studies have demonstrated that enterovirus infections such as coxsackievirus type B (CVB) are associated with triggering T1D. Prior to autoantibody development in T1D, viral RNA and antibodies against CVB can be detected within the blood, stool, and pancreata. An innate pathogen recognition receptor, melanoma differentiation-associated protein 5 (MDA5), which is encoded by the IFIH1 gene, has been associated with T1D onset. It is unclear how single nucleotide polymorphisms in IFIH1 alter the structure and function of MDA5 that may lead to exacerbated antiviral responses contributing to increased T1D-susceptibility. Binding of viral dsRNA via MDA5 induces synthesis of antiviral proteins such as interferon-alpha and -beta (IFN-α/β). Viral infection and subsequent IFN-α/β synthesis can lead to ER stress within insulin-producing β-cells causing neo-epitope generation, activation of β-cell-specific autoreactive T cells, and β-cell destruction. Therefore, an interplay between genetics, enteroviral infections, and antiviral responses may be critical for T1D development.