An Update on the Chemokine System in the Development of NAFLD.

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world. Sustained hepatic inflammation is a key driver of the transition from simple fatty liver to nonalcoholic steatohepatitis (NASH), the more aggressive form of NAFLD. Hepatic inflammation is orchestrated by chemokines, a family of chemoattractant cytokines that are produced by hepatocytes, Kupffer cells (liver resident macrophages), hepatic stellate cells, endothelial cells, and vascular smooth muscle cells. Over the last three decades, accumulating evidence from both clinical and experimental investigations demonstrated that chemokines and their receptors are increased in the livers of NAFLD patients and that CC chemokine ligand (CCL) 2 and CCL5 in particular play a pivotal role in inducing insulin resistance, steatosis, inflammation, and fibrosis in liver disease. Cenicriviroc (CVC), a dual antagonist of these chemokines' receptors, CCR2 and CCR5, has been tested in clinical trials in patients with NASH-associated liver fibrosis. Additionally, recent studies revealed that other chemokines, such as CCL3, CCL25, CX3C chemokine ligand 1 (CX3CL1), CXC chemokine ligand 1 (CXCL1), and CXCL16, can also contribute to the pathogenesis of NAFLD. Here, we review recent updates on the roles of chemokines in the development of NAFLD and their blockade as a potential therapeutic approach.

Tumor-infiltrating lymphocytes predict survival outcomes in patients with cervical cancer treated with concurrent chemoradiotherapy.

OBJECTIVES: To (i) identify correlations between selected immunogenic factors and clinicopathological characteristics, (ii) determine whether intratumoral abundance of various specific tumor-infiltrating lymphocytes (TILs) is a prognostic indicator in women with Stage II and III cervical cancer who undergo treatment with cisplatin-based concurrent chemoradiotherapy (CCRT), and (iii) investigate subtypes of FOXP3+ T cells in 15 fresh samples of cervical cancer. METHODS: In this retrospective study, intratumoral lesions in colposcopic biopsies from 55 women with advanced cervical cancer who subsequently underwent CCRT at our institution were subjected to automatic immunological staining using the following six mouse monoclonal antibodies: anti-CD3, anti-CD4, anti-CD8, anti-CD20, anti-CD206, and anti-FOXP3. Associations between the findings on automatic scoring of the number of each type of TIL in each specimen and various clinicopathological characteristics were analyzed, as were associations between the abundance of various specific types of TIL and survival. Subtypes of FOXP3+ TILs in 15 additional fresh tumor samples were also investigated using flow cytometry. RESULTS: Infiltration with CD8+ TILs was associated with pelvic lymph node metastasis. Abundant infiltration by CD3+, CD4+, CD8+, CD206+, and FOXP3+ TILs were statistically significant indicators of better progression-free and overall survival. Regarding subtypes of FOXP3+ TILs, non-Tregs (Fr-III) were found in all samples tested for this. CONCLUSIONS: The abundance of various specific intratumoral TILs may be prognostic indicators in patients with advanced cervical cancer undergoing CCRT.

Pirfenidone prevents and reverses hepatic insulin resistance and steatohepatitis by polarizing M2 macrophages.

Nonalcoholic steatohepatitis (NASH) is associated with lipotoxic liver injury, leading to insulin resistance, inflammation, and fibrosis. Despite its increased global incidence, very few promising treatments for NASH are available. Pirfenidone is an antifibrotic agent used to treat pulmonary fibrosis; it suppresses the pulmonary influx of T cells and macrophages. Here, we investigated the effect of pirfenidone in a mouse model of lipotoxicity-induced NASH via a high-cholesterol and high-fat diet. After 12 weeks of feeding, pirfenidone administration attenuated excessive hepatic lipid accumulation and peroxidation by reducing the expression of genes related to lipogenesis and fatty acid synthesis and enhancing the expression of those related to fatty acid oxidation. Flow cytometry indicated that pirfenidone reduced the number of total hepatic macrophages, particularly CD11c+CD206-(M1)-type macrophages, increased the number of CD11c-CD206+(M2)-type macrophages, and subsequently reduced T-cell numbers, which helped improve insulin resistance and steatohepatitis. Moreover, pirfenidone downregulated the lipopolysaccharide (LPS)-induced mRNA expression of M1 marker genes and upregulated IL-4-induced M2 marker genes in a dose-dependent manner in RAW264.7 macrophages. Importantly, pirfenidone reversed insulin resistance, hepatic inflammation, and fibrosis in mice with pre-existing NASH. These findings suggest that pirfenidone is a potential candidate for the treatment of NASH.

Developing a Decision-Aid Website for Breast Cancer Surgery: An Action Research Approach.

BACKGROUND: Patients with early-stage breast cancer have numerous options when choosing the type of breast surgery method to be applied. Each of these options lead to a similar long-term survival rate, but result in significant differences in appearance, function, cost, recurrence rate, and various other relevant considerations. However, the time available for detailed communication with each patient is often limited in clinics, which puts these women under great psychological stress and can hinder their surgery-related decision making. OBJECTIVE: The objective of this study was to develop a multipurpose surgery decision-making website providing medical information, psychological support, and decision-related simulation for women during breast cancer surgery-related decision making. METHODS: Using the 4 steps of action research, which involve multigroup teamwork via regular team meetings, the following were performed: (1) Planning: searching, analyzing, and evaluating health websites to consensually decide the major infrastructure; (2) Action: work was performed simultaneously in 4 groups, which consisted of medical information collection and editing, patient interviews and data extraction, webpage content design, and programming to create or host the website; (3) Evaluation: the website was tested by clinical experts and focus groups of former breast cancer patients to assess its effectiveness and pinpoint appropriate improvements; and (4) Reflection: constant dialogue was conducted between the various participants at each step, which was used as the foundation and motivation of next plan-action-evaluation-reflection circle. RESULTS: Using the action research approach, we completed the development of our website, which includes the following: (1) "Woman's Voice"-an animated comic depicting the story of a female breast cancer patient with interspersed questions for the users that will help them better empathize with the experience; (2) "Cancer Information Treasure House"-providing breast cancer surgery-related information through text, tables, pictures and a presentation video; (3) "Decision-making Simulator"-helping patients think through and check the pros and cons of the different surgical options via visual-based interactions including "Stairs Climbing" and "Fruit of Hope"; and (4) "Recommended Links"-providing reliable websites for further reference. Additionally, we have further improved the website based on the feedback received from postsurgery breast cancer patients and clinicians. We hope to continue improving to better meet both the patients' and health providers' needs and become a practical decision-making aid for patients undergoing breast cancer surgery. CONCLUSIONS: We have created the first breast cancer surgery decision-making assistance tool in Taiwan using a "Web-based" and multifunctional website design. This site aims to provide health care knowledge, psychological healing, and emotional support functions, as well as decision-making capability enhancement simulations. We look forward to assisting breast cancer patients in their decision-making process and expect our website to increase patient's autonomy and improve their communication with clinicians.

The association of matrix metalloproteinas-2 promoter polymorphisms with lung cancer susceptibility in Taiwan.

Matrix metalloproteinases-2 (MMP2) has been reported to be overexpressed in various types of cancer. However, the contribution of various genotypes of MMP2 to lung cancer is controversial and not yet been examined in Taiwan. Therefore, in the current study, we investigated the association of MMP2 genotypes with lung cancer risk among Taiwanese. In this hospital-based, case-control study, 358 lung cancer patients and 716 age- and gender-matched healthy controls were recruited, and the genotypic distributions of MMP2-1306 and MMP2- 735 were determined. Then, their association with lung cancer was evaluated, and their interaction with personal smoking status was also examined via stratification analysis. The results showed that the percentages of variant CT and TT at MMP2-1306 were 17.3% and 1.7% among the lung cancer patients, respectively, much lower than those of 28.7% and 2.4%, respectively, among the healthy controls (P for trend = 0.0001). The allelic frequency distribution analysis showed that the variant T allele at MMP2-1306 conferred a statistically significantly lower lung cancer risk than the wild-type C allele (adjusted odds ratio = 0.54, 95% confidence interval = 0.41-0.72, P = 0.0001). There was an obvious effect of MMP2-1306 genotype on lung cancer risk among the subpopulations of ever smokers but not nonsmokers. As for the genotypes of MMP2-735, there was no such differential distribution in the aspects of genotypic or allelic frequencies, or combinative effects with smoking status. The genotypes of MMP2-1306 may act as a biomarker in determining personal susceptibility to lung cancer in Taiwan. The contribution of MMP2 genotypes alone and its joint effects with personal cigarette smoking habit on lung cancer susceptibility should be taken into consideration of the clinical practices for early detection and prediction of lung cancer in Taiwan.

Reply to the Letter to the Editor by Li et al.: Bioinformatics Analysis in Mice with Diet-Induced Nonalcoholic Steatohepatitis Treated with Astaxanthin and Vitamin E.

n/a.

Hepatic Transcriptome Profiles of Mice with Diet-Induced Nonalcoholic Steatohepatitis Treated with Astaxanthin and Vitamin E.

Astaxanthin alleviates hepatic lipid accumulation and peroxidation, inflammation, and fibrosis in mice with high-cholesterol, high-cholate, and high-fat (CL) diet-induced nonalcoholic steatohepatitis (NASH) [...].

Effects of TBEP on the induction of oxidative stress and endocrine disruption in Tm3 Leydig cells.

The flame retardant tris (2-butoxyethyl) phosphate (TBEP) is a frequently detected contaminant in the environment. In the cultured TM3 cells (originated from ATCC), effects of TBEP on the induction of oxidative stress and endocrine disruption were evaluated. It was observed that exposure to 100 µg/mL TBEP for 24 h significantly reduced the viability of TM3 cells. The mRNA levels of genes related to oxidative stress including Sod, Gpx1, Cat, and Gsta1 were changed in a dose-dependent and/or time-dependent manner after exposure to 30 and 100 µg/mL TBEP for 6, 12, or 24 h. Moreover, notable decrease in glutathione (GSH) contents and increases in oxidized glutathione (GSSG) contents as well as the antioxidant enzyme activities like superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase were found in the group treated with 100 µg/mL TBEP for 24 h, indicating that TBEP induced oxidative stress in TM3 Leydig cells. In addition, the expression of genes related to testosterone (T) synthesis including cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), cytochrome P450 17α-hydroxysteroid dehydrogenase (P450-17α), and 17ß-hydroxysteroid dehydrogenase (17ß-HSD) and T levels in medium were remarkably declined by the treatment of 100 µg/mL TBEP for 24 h. And TBEP could inhibit the expression of P450-17α and 17ß-HSD and T levels up-regulated by hCG in TM3 cells. Taken together, these findings indicated that TBEP can induce oxidative stress and alter steroidogenesis in TM3 cells. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1276-1286, 2016.

Micronutrient Antioxidants and Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) is one of the most important chronic liver diseases worldwide and has garnered increasing attention in recent decades. NAFLD is characterized by a wide range of liver changes, from simple steatosis to nonalcoholic steatohepatitis, cirrhosis, and hepatocellular carcinoma. The blurred pathogenesis of NAFLD is very complicated and involves lipid accumulation, insulin resistance, inflammation, and fibrogenesis. NAFLD is closely associated with complications such as obesity, diabetes, steatohepatitis, and liver fibrosis. During the progression of NAFLD, reactive oxygen species (ROS) are activated and induce oxidative stress. Recent attempts at establishing effective NAFLD therapy have identified potential micronutrient antioxidants that may reduce the accumulation of ROS and finally ameliorate the disease. In this review, we present the molecular mechanisms involved in the pathogenesis of NAFLD and introduce some dietary antioxidants that may be used to prevent or cure NAFLD, such as vitamin D, E, and astaxanthin.

Pericardial Effusion Detection on Post-Mortem Computed Tomography Images Using Convolutional Neural Networks.

Pericardial effusion can be a sign of significant underlying diease and, in some cases, may lead to death. Post-mortem computed tomography (PMCT) is a well-established tool to assist death investigation processes in the forensic setting. In practice, the scarcity of well-trained radiologists is a challenge in processing raw whole-body PMCT images for pericardial effusion detection. In this work, we propose a Pericardial Effusion Automatic Detection (PEAD) framework to automatically process raw whole-body PMCT images to filter out the irrelevant images with heart organ absent and focus on pericardial effusion detection. In PEAD, the standard convolutional neural network architectures of VGG and ResNet are carefully modified to fit the specific characteristics of PMCT images. The experimental results prove the effectiveness of the proposed framework and modified models. The modified VGG and ResNet models achieved superior detection accuracy than the standard architecture with reduced processing speed.

Cenicriviroc Suppresses and Reverses Steatohepatitis by Regulating Macrophage Infiltration and M2 Polarization in Mice.

The inhibition of hepatic macrophage and Kupfer cell recruitment and activation is a potential strategy for treating insulin resistance and nonalcoholic steatohepatitis (NASH). Cenicriviroc (CVC), a dual C-C chemokine receptor 2 (CCR2) and CCR5 antagonist, has shown antifibrotic activity in murine models of NASH and has been evaluated in clinical trials on patients with NASH. This study investigated the effects of CVC on macrophage infiltration and polarization in a lipotoxic model of NASH. C57BL/6 mice were fed a high-cholesterol, high-fat (CL) diet or a CL diet containing 0.015% CVC (CL + CVC) for 12 weeks. Macrophage recruitment and activation were assayed by immunohistochemistry and flow cytometry. CVC supplementation attenuated excessive hepatic lipid accumulation and peroxidation and alleviated glucose intolerance and hyperinsulinemia in the mice that were fed the CL diet. Flow cytometry analysis revealed that compared with the CL group, mice fed the CL + CVC diet had fewer M1-like macrophages, more M2-like macrophages, and fewer T cell counts, indicating that CVC caused an M2-dominant shift of macrophages in the liver. Similarly, CVC decreased lipopolysaccharide-stimulated M1-like macrophage activation, whereas it increased interleukin-4-induced M2-type macrophage polarization in vitro. In addition, CVC attenuated hepatic fibrosis by repressing hepatic stellate cell activation. Lastly, CVC reversed insulin resistance as well as steatosis, inflammation, and fibrosis of the liver in mice with pre-existing NASH. In conclusion, CVC prevented and reversed hepatic steatosis, insulin resistance, inflammation, and fibrogenesis in the liver of NASH mice via M2 macrophage polarization.

Circ_0068481 Affects the Human Pulmonary Artery Smooth Muscle Cells' Progression by miR-361-3p/KLF5 Axis.

BACKGROUND: Uncontrolled proliferation of pulmonary artery smooth muscle cells (PASMCs) contributes to the pathogenesis of pulmonary arterial hypertension (PAH). In this work, we defined the precise part of circ_0068481 in PASMC proliferation and migration induced by hypoxia. We hypothesized that circ_0068481 enhanced hypoxia-induced PASMC proliferation, invasion, and migration through the microRNA (miR)-361-3p/Krüppel-like factor 5 (KLF5) pathway. METHODS: Human PASMCs (hPASMCs) were exposed to hypoxic (3% O2) conditions. Circ_0068481, miR-361-3p, and KLF5 levels were gauged by qRT-PCR and western blot. Cell viability, proliferation, invasion, and migration were detected by XTT, EdU incorporation, transwell, and wound-healing assays, respectively. Dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays were performed to confirm the direct relationship between miR-361-3p and circ_0068481 or KLF5. RESULTS: Circ_0068481 expression was increased in the serum of PAH patients and hypoxia-induced hPASMCs. Downregulation of circ_0068481 attenuated hypoxia-induced promotion in hPASMC proliferation, invasion, and migration. Circ_0068481 directly targeted miR-361-3p, and miR-361-3p downregulation reversed the inhibitory effects of circ_0068481 silencing on hypoxia-induced hPASMC proliferation, invasion, and migration. KLF5 was a direct miR-361-3p target, and miR-361-3p upregulation mitigated hypoxia-induced hPASMC proliferation, invasion, and migration by inhibiting KLF5 expression. Moreover, circ_0068481-induced KLF5 expression by binding to miR-361-3p in hypoxic hPASMCs. CONCLUSIONS: Circ_0068481 knockdown ameliorated hypoxia-induced hPASMC proliferation, invasion, and migration at least in part through the miR-361-3p/KLF5 axis.

Neuropathic pain in hereditary coproporphyria.

Acute porphyrias are rare diseases with varying incidences worldwide. These diseases are disorders of heme biosynthesis characterized by acute attacks of neurological symptoms. Acute porphyria should be considered in patients with unexplained abdominal pain or neurological damage. Clinical manifestations of acute porphyria are nonspecific and are associated with multiple organ systems. This report examines a rare case of an uncommon type of acute porphyria in a patient with an initial presentation of abdominal pain and progressive polyneuropathy.

Neo-Antigen-Reactive T Cells Immunotherapy for Colorectal Cancer: A More Personalized Cancer Therapy Approach.

Colorectal cancer (CRC) is the second most common malignancy in women and the third most frequent cancer in men. Evidence has revealed that the survival of patients with metastatic CRC is very low, between one and three years. Neoantigens are known proteins encoded by mutations in tumor cells. It is theorized that recognizing neoantigens by T cells leads to T cell activation and further antitumor responses. Neoantigen-reactive T cells (NRTs) are designed against the mentioned neoantigens expressed by tumor cells. NRTs selectively kill tumor cells without damage to non-cancerous cells. Identifying patient-specific and high immunogen neoantigens is important in NRT immunotherapy of patients with CRC. However, the main challenges are the side effects and preparation of NRTs, as well as the effectiveness of these cells in vivo. This review summarized the properties of neoantigens as well as the preparation and therapeutic outcomes of NRTs for the treatment of CRC.

Evaluation of CD4+ cells infiltration as a prognostic factor in cervical intraepithelial neoplasia 2.

OBJECTIVE: To identify candidate predictors for the prognosis of cervical intraepithelial neoplasia 2 (CIN2) lesions and evaluate the prognostic value of the local immune response. METHODS: One hundred fifteen CIN2 patients were enrolled. The percentage of p16-, minichromosome maintenance complex component 2- or apolipoprotein B mRNA editing enzyme catalytic subunit 3G (APOBEC3G)-positive cells was determined immunohistochemically. Tumor-infiltrating lymphocytes (TILs) in intertumoral lesions were scored using an automated system. CIN3 disease progression and regression rates were estimated by the Kaplan-Meier method. A case-control study was conducted to screen CIN2 prognostic factors in 10 regression and 10 progression patients. Selected factors were examined in a cohort study to determine their prognostic value for CIN2. RESULTS: Among all participants, the cumulative progression and regression rates at 60 months were 0.477 and 0.510, respectively. In the case-control study, p16- and APOBEC3G-positive cells were higher in the progression group (p=0.043, p=0.023). Additionally, CD4+ cell infiltration was enhanced in the regression group (p=0.023). The cohort study revealed a significantly increased progression rate in patients with elevated p16-positive cells (p<0.001), and increased CD4+ TIL infiltration was associated with better regression (p=0.011). Kaplan-Meier analysis according to human papillomavirus (HPV) positivity revealed a greater CIN3 development risk in HPV16-positive patients than in HPV16-negative cases. Finally, multivariate analysis identified HPV16 infection and CD4+ TIL infiltration as independent prognostic factors in CIN2 regression. CONCLUSION: CD4+ TIL infiltration in intertumoral lesions was related with CIN2 regression. Our findings suggest CD4+ TIL infiltration may be useful for the triage of CIN2 patients.

The Association of DNA Ligase 1 Rs20579 Polymorphism With Lung Cancer Risk Among Taiwanese.

BACKGROUND/AIM: Impaired DNA repair capacity may play a critical role in genome instability and carcinogenesis. However, the impact of DNA ligase 1 (Lig1) genotypes on tumorigenesis remains unclear. This study aimed to investigate the contribution of Lig1 rs20579 genotypes to the risk of developing lung cancer, and review the related literature. MATERIALS AND METHODS: Polymerase chain reaction-restriction fragment length polymorphism analysis was used to determine the genotypes of Lig1 rs20579 and evaluate their association with lung cancer risk among 358 lung cancer cases and 716 age- and sex-matched cancer-free control subjects. RESULTS: The distribution of GG, AG, and AA genotypes for Lig1 rs20579 was 77.1%, 20.8%, and 2.1% among the controls, and 76.0%, 21.5%, and 2.5% among the lung cancer cases (p for trend=0.8686). There was no significant difference in the distribution of AG and AA genotypes between the two groups (p=0.8257 and 0.8098, respectively). Allelic frequency analysis indicated that individuals carrying the variant A allele for Lig1 rs20579 had a non-significant 1.07-fold higher risk of developing lung cancer than those carrying the wild-type G allele [95% confidence interval (CI)=0.82-1.40, p=0.6639]. Furthermore, no differential distribution of the Lig1 rs20579 genotype was found among non-smokers (p=0.9910) or smokers (p=0.9001). CONCLUSION: In contrast to Americans, Lig1 rs20579 genotypes do not appear to play a critical role in determining susceptibility to lung cancer among Taiwanese individuals.

Identifying the core concepts of pharmacology education: A global initiative.

BACKGROUND AND PURPOSE: In recent decades, a focus on the most critical and fundamental concepts has proven highly advantageous to students and educators in many science disciplines. Pharmacology, unlike microbiology, biochemistry, or physiology, lacks a consensus list of such core concepts. EXPERIMENTAL APPROACH: We sought to develop a research-based, globally relevant list of core concepts that all students completing a foundational pharmacology course should master. This two-part project consisted of exploratory and refinement phases. The exploratory phase involved empirical data mining of the introductory sections of five key textbooks, in parallel with an online survey of over 200 pharmacology educators from 17 countries across six continents. The refinement phase involved three Delphi rounds involving 24 experts from 15 countries across six continents. KEY RESULTS: The exploratory phase resulted in a consolidated list of 74 candidate core concepts. In the refinement phase, the expert group produced a consensus list of 25 core concepts of pharmacology. CONCLUSION AND IMPLICATIONS: This list will allow pharmacology educators everywhere to focus their efforts on the conceptual knowledge perceived to matter most by experts within the discipline. Next steps for this project include defining and unpacking each core concept and developing resources to help pharmacology educators globally teach and assess these concepts within their educational contexts.

Single-layered graphene oxide nanosheet/polyaniline hybrids fabricated through direct molecular exfoliation.

In this study, we used direct molecular exfoliation for the rapid, facile, large-scale fabrication of single-layered graphene oxide nanosheets (GOSs). Using macromolecular polyaniline (PANI) as a layered space enlarger, we readily and rapidly synthesized individual GOSs at room temperature through the in situ polymerization of aniline on the 2D GOS platform. The chemically modified GOS platelets formed unique 2D-layered GOS/PANI hybrids, with the PANI nanorods embedded between the GO interlayers and extended over the GO surface. X-ray diffraction revealed that intergallery expansion occurred in the GO basal spacing after the PANI nanorods had anchored and grown onto the surface of the GO layer. Transparent folding GOSs were, therefore, observed in transmission electron microscopy images. GOS/PANI nanohybrids possessing high conductivities and large work functions have the potential for application as electrode materials in optoelectronic devices. Our dispersion/exfoliation methodology is a facile means of preparing individual GOS platelets with high throughput, potentially expanding the applicability of nanographene oxide materials.

Mycoplasma pneumoniae and Chlamydia pneumoniae Coinfection with Acute Respiratory Distress Syndrome: A Case Report.

Community-acquired pneumonia caused by Mycoplasma pneumoniae or Chlamydia pneumoniae is usually mild. Mycoplasma pneumoniae-related and C. pneumoniae-related acute respiratory distress syndromes (ARDSs) are rare. Moreover, to our knowledge, there are no published reports on ARDS caused by M. pneumoniae and C. pneumoniae coinfection. Here, we report a case of an immunocompetent young woman who was co-infected with M. pneumoniae and C. pneumoniae and was started on treatment with piperacillin and clarithromycin. Two days later, she developed ARDS. She recovered rapidly following a change of antibiotic treatment to levofloxacin and was discharged on day 12. We conducted exome sequencing followed by alternative filtering to search for candidate ARDS-related genes. We identified an intronic variant of unknown significance within leucine-rich repeat-containing 16A (LRRC16A), a gene previously identified as a significant locus for platelet count with a possible role in ARDS. This is a rare case of ARDS in a young adult caused by M. pneumoniae and C. pneumoniae coinfection. This case suggests that ARDS in young adults may be correlated with variants in LRRC16A. This requires confirmation by further case reports.

Students' experience of online learning during the COVID-19 pandemic: A province-wide survey study.

Online learning is currently adopted by educational institutions worldwide to provide students with ongoing education during the COVID-19 pandemic. Even though online learning research has been advancing in uncovering student experiences in various settings (i.e., tertiary, adult, and professional education), very little progress has been achieved in understanding the experience of the K-12 student population, especially when narrowed down to different school-year segments (i.e., primary and secondary school students). This study explores how students at different stages of their K-12 education reacted to the mandatory full-time online learning during the COVID-19 pandemic. For this purpose, we conducted a province-wide survey study in which the online learning experience of 1,170,769 Chinese students was collected from the Guangdong Province of China. We performed cross-tabulation and Chi-square analysis to compare students' online learning conditions, experiences, and expectations. Results from this survey study provide evidence that students' online learning experiences are significantly different across school years. Foremost, policy implications were made to advise government authorises and schools on improving the delivery of online learning, and potential directions were identified for future research into K-12 online learning.