Common underlying diseases do not contribute in determining the causes of sudden unexplained death

Background Underlying diseases have a statistically significant positive correlation to sudden death. However, sudden unexplained death （SUD） is different from sudden death, as there is no clinical evidence to support the sudden death due to the original underlying disease, nor a lethal pathological basis to be found during autopsy. In addition, SUD are more common in young, previously healthy individuals, usually without any signs of disease, with no positive lesions found after autopsy. Therefore, a causal relationship between SUD and the underlying disease needs to be further explored. This study aimed to explore the role that common underlying diseases play in patients with SUD and to reveal the correlation between them. Methods The medical records, history and case information of 208 patients with SUD were collected for the survey. All these SUD occurred in the emergency room of Peking University Third Hospital from January 2006 to December 2009. The patients were stratified by with and without common underlying diseases. To examine possible associations between the underlying diseases and the cause of unexplained sudden death, the chi-squared and Fisher＇s exact tests were used. Results Among the 208 patients, 65 were diagnosed with common underlying diseases while 143 were not. Within these two groups, there were 45 patients for whom the clear cause of death was determined. However, there were no statistically significant differences or strong associations （x2=1.238, P 〉0.05） between the 11 patients with （16.90%） and 34 without （23.78%） common underlying disease among these 45 patients. We also found that occurrence of the common underlying diseases, such as neurological system, cardiovascular and pulmonary system diseases, are not statistically significant （P 〉0.05） in the diagnosis of the SUD. Conclusion Common underlying diseases make no obvious contributions to SUD and are not useful in diagnosing the underlying reasons for death.

Streptozotocin induced Alzheimer's disease like changes and the underlying neural degeneration and regeneration mechanism

Alzheimer’s disease（AD）is a neurodegenerative disorder which is remarkably characterized by pathological hallmarks that include neurofibrillary tangles,neuronal loss extracellular senile plaques containing aggregated amyloid beta（Aβ）,and neurofibrillary tangles composed of the hyperphosphorylated form of the microtubule protein tau.It is the most common form of dementia which is characterized by severe neurodegenerative changes such as loss of neurons and synapses in brain（Kamat et al.,2014）.

Clinical features of elderly patients with COVID-19 in Wuhan,China

BACKGROUND Elderly patients with coronavirus disease 2019(COVID-19)who have comorbidities,frailty or profound disabilities experience poor outcomes.We analyzed the clinical characteristics of elderly patients from Wuhan who had COVID-19 during the early stages of the pandemic.AIM To identify factors affecting the early mortality of elderly patients with COVID-19.METHODS The records of 234 patients who were 65-years-old or more and were hospitalized in Wuhan Huoshenshan Hospital from February 4 to March 4,2020 were reviewed.All patients had confirmed COVID-19 and the final date of follow-up was April 4,2020.RESULTS There were 163 cases of mild disease(69.66%),39 cases of severe disease(16.67%)and 32 cases of critical disease(13.68%).Twenty-nine patients died within 1 mo(12.40%),all of whom had critical disease.Surviving patients and deceased patients had no significant differences in age or chronic diseases.Overall,the most common symptoms were fever(65.4%),dry cough(57.3%),fatigue(47.4%)and shortness of breath(41%).The deceased patients had higher levels of multiple disease markers(C-reactive protein,D-dimer,lactate dehydrogenase,alanine amino transferase,aspartate aminotransferase,creatinine kinase and creatinine kinase-MB)and higher incidences of lymphocytopenia and hypoproteinemia.CONCLUSION This single-center study of elderly patients from Wuhan,China who were hospitalized with COVID-19 indicated that age and chronic diseases were not associated with mortality.Hypertension,diabetes and cardiovascular disease were the most common comorbidities and the most common symptoms were fever,dry cough,fatigue and shortness of breath.Lymphocytopenia,increased levels of D-dimer and other markers indicative of damage to the heart,kidneys or liver were associated with an increased risk of death.

Effects of COVID-19 on the liver:The experience of a single center

BACKGROUND The coronavirus disease 2019(COVID-19)was perhaps the most severe global health crisis in living memory.Alongside respiratory symptoms,elevated liver enzymes,abnormal liver function,and even acute liver failure were reported in patients suffering from severe acute respiratory disease coronavirus 2 pneumonia.However,the precise triggers of these forms of liver damage and how they affect the course and outcomes of COVID-19 itself remain unclear.AIM To analyze the impact of liver enzyme abnormalities on the severity and outcomes of COVID-19 in hospitalized patients.METHODS In this study,684 depersonalized medical records from patients hospitalized with COVID-19 during the 2020-2021 period were analyzed.COVID-19 was diagnosed according to the guidelines of the National Institutes of Health(2021).Patients were assigned to two groups:those with elevated liver enzymes(Group 1:603 patients),where at least one out of four liver enzymes were elevated(following the norm of hospital laboratory tests:alanine aminotransferase(ALT)≥40,aspartate aminotransferase(AST)≥40,gamma-glutamyl transferase≥36,or alkaline phosphatase≥150)at any point of hospitalization,from admission to discharge;and the control group(Group 2:81 patients),with normal liver enzymes during hospitalization.COVID-19 severity was assessed according to the interim World Health Organization guidance(2022).Data on viral pneumonia complications,laboratory tests,and underlying diseases were also collected and analyzed.RESULTS In total,603(88.2%)patients produced abnormal liver test results.ALT and AST levels were elevated by a factor of less than 3 in 54.9%and 74.8%of cases with increased enzyme levels,respectively.Patients in Group 1 had almost double the chance of bacterial viral pneumonia complications[odds ratio(OR)=1.73,P=0.0217],required oxygen supply more often,and displayed higher biochemical inflammation indices than those in Group 2.No differences in other COVID-19 complications or underlying diseases were observed between groups.Preexisting hepatitis of a different etiology was rarely documented(in only 3.5%of patients),and had no impact on the severity of COVID-19.Only 5(0.73%)patients experienced acute liver failure,4 of whom died.Overall,the majority of the deceased patients(17 out of 20)had elevated liver enzymes,and most were male.All deceased patients had at least one underlying disease or combination thereof,and the deceased suffered significantly more often from heart diseases,hypertension,and urinary tract infections than those who made recoveries.Alongside male gender(OR=1.72,P=0.0161)and older age(OR=1.02,P=0.0234),diabetes(OR=3.22,P=0.0016)and hyperlipidemia(OR=2.67,P=0.0238),but not obesity,were confirmed as independent factors associated with more a severe COVID-19 infection in our cohort.CONCLUSION In our study,the presence of liver impairment allows us to predict a more severe inflammation with a higher risk of bacterial complication and worse outcomes of COVID-19.Therefore,patients with severe disease forms should have their liver tests monitored regularly and their results should be considered when selecting treatment to avoid further liver damage or even insufficiency.