This study aims to establish a high-performance size-exclusion chromatography (HPSEC) method for determining the content of the classical swine fever virus (CSFV) E2 protein and screen the optimal stabilizer to enhance the stability of this protein. The optimal detection conditions were determined by optimizing the composition of the mobile phase, and characteristic chromatographic peaks were identified by SDS-PAGE and Western blotting. The specificity, repeatability, precision, linearity, limit of detection (LOD), and limit of quantitation (LOQ) of the method were assessed. The method established was used to determine the content of CSFV E2 protein antigen and vaccine. Differential scanning fluorimetry (DSF) was employed to screen the buffer system, pH, and salt ion concentrations, and sugar, amino acid, and alcohol stabilizers were further screened. The results showed that using a 200 mmol/L phosphate buffer provided the best column efficiency. An antigen-specific chromatographic peak appeared at the retention time of 18 min, which was identified as the CSFV E2 protein by SDS-PAGE and Western blotting. The method exhibited high specificity for detecting the CSFV E2 protein, with no absorbance peak observed in the blank control. The relative standard deviation (RSD) of the peak area for six repeated injections of the CSFV E2 protein was 0.74%, indicating good repeatability of the method. The RSD for repeated detection of two different concentrations of CSFV E2 protein samples by different operators at different time points was less than 2%, suggesting good intermediate precision of the method. The peak area of the CSFV E2 protein was linearly related to its concentration, with the regression equation showing R² of 1.000. The LOD and LOQ of the method were 14.88 μg/mL and 29.75 μg/mL, respectively. Application of the developed method in the detection of three batches of CSFV E2 protein antigen and three batches of vaccine demonstrated results consistent with those from the bicinchoninic acid (BCA) assay, which meant that the method could accurately determine the content of CSFV E2 protein antigen and vaccine. The DSF method identified 50 mmol/L Tris-HCl at pH 8.0 as the optimal buffer, and the addition of sugar and alcohol stabilizers further improved the stability of the CSFV E2 protein. The HPSEC method established in this study is simple, fast, and exhibits good accuracy and repeatability, enabling precise measurement of the CSFV E2 protein content. It is expected to play a crucial role in the quality control of the CSFV E2 vaccine. Furthermore, the strategy for improving the CSFV E2 protein stability, identified through DSF screening, has significant implications for enhancing the stability of the CSFV E2 vaccine.
Classical Swine Fever Virus/chemistry* ; Chromatography, Gel/methods* ; Animals ; Swine ; Viral Envelope Proteins/immunology*

The Ebola virus (EBOV), a member of the Filoviridae family, is a highly pathogenic agent responsible for severe hemorrhagic fever in humans. Understanding the molecular mechanisms governing its replication is critical for developing effective antiviral strategies. VP35-TurboID immunosuppression coupled with quantitative mass spectrometry identified Septin9, the host GTP-binding protein which played a role in cytoskeletal regulation, as a novel interactor of VP35. Western blotting and Far-Western blotting confirmed the direct interaction and demonstrated that the C-terminal region of VP35 was the critical binding domain. Functionally, EBOV replication as well as the formation of viral inclusion bodies (VIBs) was demonstrated to be significantly suppressed by Septin9 knockdown and depletion, as shown by the EBOV minigenome (EBOV MG) and the transcription- and replication-competent virus-like particles (trVLPs) system. This study reveals that VP35 engages in a specific interaction with the GTP-binding protein Septin9, thereby impeding EBOV replication through the disruption of inclusion bodies. The overarching objective of this study is to significantly enhance our understanding about the pathogenic mechanism of EBOV and offer a robust theoretical foundation and solid empirical support for the formulation of innovative therapeutic strategies against EBOV.
Virus Replication/physiology* ; Septins/physiology* ; Humans ; Ebolavirus/physiology* ; Inclusion Bodies, Viral/metabolism* ; Viral Regulatory and Accessory Proteins/metabolism* ; Hemorrhagic Fever, Ebola/virology*

Japanese spotted fever(JSF)is an infectious disease caused by Rickettsia japonica,with nonspecific clinical symptoms and a high risk of misdiagnosis.We reported a case of JSF,in which Rickettsia japonica was detected in blood cells by metagenomic next-generation sequencing.The patient recovered after treatment with doxycycline.This report provides a reference for the clinical diagnosis and treatment of JSF.
Humans ; High-Throughput Nucleotide Sequencing ; Metagenomics ; Rickettsia/isolation & purification* ; Spotted Fever Group Rickettsiosis/microbiology*

The patient was a girl, aged 10 years, who was admitted due to fever for 5 days and pancytopenia in peripheral blood for 2 days. Bone marrow examination showed the presence of phagocytic activity, and peripheral blood tests showed pancytopenia, an increase in ferritin, a reduction in fibrinogen, increases in triglyceride and sCD25, and a reduction in natural killer cell activity, which led to the diagnosis of hemophagocytic lymphohistiocytosis (HLH). On the day of admission, the child developed convulsions and rapidly progressed to refractory status epilepticus, which was consistent with the manifestations of febrile infection-related epilepsy syndrome. HLH was controlled after active immunotherapy, with the sequela of refractory epilepsy, and her cognitive function was essentially within normal limits. This article reports the condition of febrile infection-related epilepsy syndrome caused by HLH for the first time in China, in order to improve the awareness of this disease among clinicians.
Humans ; Lymphohistiocytosis, Hemophagocytic/complications* ; Female ; Child ; Epilepsy/etiology* ; Fever/etiology* ; Epileptic Syndromes/etiology*

INTRODUCTION

Childhood Polyarteritis Nodosa (PAN) is a rare, systemic necrotizing vasculitis of the small to medium-sized vessels with an uncertain global distribution. The primary etiology is unknown. However, PAN is commonly associated with preceding Group A streptococcus infection in children. The most common cutaneous manifestations of PAN include tender subcutaneous nodules, livedo reticularis, digital ischemia and ulceration. To date, no reports have documented cutaneous PAN as a sequela of rheumatic fever.

This is a report of a 7-year-old Filipino male who presented with multiple, well-defined erythematous to hyperpigmented, firm, tender nodules, with some areas of lace or net-like macules and patches, some resolved leaving hyperpigmentation measuring 1x1 cm to 2x2 cm on the lower back, bilateral upper and lower extremities accompanied by fever, malaise, arthralgia and myalgia with a previous history of rheumatic fever. A 6mm skin punch biopsy revealed findings consistent with PAN. The patient was managed with prednisone. Due to the limited response to treatment, he was eventually given mycophenolate mofetil.

Childhood polyarteritis nodosa (PAN) is a rare form of necrotizing inflammation of the medium-sized blood vessels primarily linked to Group A streptococcal infection in children, with no known reported cases associated with rheumatic fever. However, in this case, we were able to observe that PAN could present as a probable rare sequela of rheumatic fever. This warrants close follow-up among such patients.

OBJECTIVE

To describe a case of dengue-associated bilateral neuroretinitis in a young female adult.

This is a case report.

A 25-year-old female was referred for evaluation of bilateral blurring of vision during the convalescent stage of dengue fever. Visual acuity was 20/80 in each eye. Fundoscopy showed mild optic disc swelling, macular thickening, and hard exudates bilaterally. Dengue-associated neuroretinitis was considered. Intravenous methylprednisolone treatment for three days resulted in significant improvements in visual function and resolution of fundus abnormalities.

Dengue is a potential etiology of neuroretinitis in endemic areas, especially in those who develop visual symptoms during the convalescent phase. Prompt recognition and treatment may prevent long-term visual impairment.

OBJECTIVE

To determine whether neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) within the first three days of dengue illness are independent predictors of dengue severity among pediatric patients.

A cross-sectional analytical retrospective study was conducted among pediatric dengue patients admitted to The Medical City, Pasig from September 2021 to August 2024. Data collection was done through electronic chart review. Baseline characteristics were analyzed using the Kruskal-Wallis test, Chi-Square test, and Fisher’s exact test. Receiver Operating Characteristic (ROC) and Area Under the Curve (AUC) analyses, along with diagnostic performance metrics, were used to evaluate daily ratio cut-offs differentiating dengue classifications. Multivariable logistic regression was performed to assess NLR and PLR as independent predictors of warning signs or severe dengue development.

Among the 316 subjects included in the analysis, 40.5% had dengue fever without warning signs, 57.3% had dengue fever with warning signs, and 2.2% had severe dengue. Differentiating patients without warning signs from those with warning signs, the NLR cut-offs were 4.73, 2.07, and 2.5 on days 1-3, respectively, whereas from those with severe dengue, the cut-offs were 1.27, 0.68, and 0.47 on the same days. For this pairwise analysis, PLR cut-offs were 170, 233.92, and 208.79 for the first comparison; and 209.24, 244.12, and 187.5 for the second, respectively. Statistical analysis showed poor discrimination and diagnostic performance for all cut-offs. Likewise, multivariable linear regression revealed no significant correlation between either ratio and dengue severity.

NLR and PLR within the first three days of dengue illness revealed poor performance in predicting the development of warning signs or progression to severe dengue among pediatric patients.

INTRODUCTION: Takayasu arteritis is the most common large-vessel vasculitis in childhood, but there is a lack of literature regarding childhood-onset Takayasu arteritis (c-TAK) in Southeast Asia. We aim to describe a c-TAK cohort in Singapore and highlight a unique subset that first presents with Kawasaki-like disease (KD). METHOD: A single-centre cohort study in Singapore of consecutive children diagnosed with c-TAK between 2002 and 2023 was performed. Demographic and clinical features, laboratory and angiographic findings, treatment, and outcomes were summarised. Disease activity was evaluated using the Paediatric Vasculitis Disease Activity Score and inflammatory markers. RESULTS: Twenty-three patients, fulfilling both the EULAR/ PRINTO/PReS and ACR/EULAR 2022 criteria, were recruited. The most common clinical features at diagnosis were fever (15, 65%) and neurological symptoms (11, 48%, half of which presented with stroke), while the most prevalent angiographic pattern by Hata's classification was Type V (21, 91%). Eight children (35%) initially presented with refractory KD, and these patients were significantly younger, more male-predominant, and had higher inflammatory markers at diagnosis; all of them had coronary artery involvement, but none had intracranial vascular findings. Of the entire cohort, 16 (70%) achieved inactive disease on medications with a median duration of 6 months (interquartile range [IQR]: 4-11), and 8 (35%) achieved remission off medications with a median duration of 43 months (IQR 35-60). CONCLUSION Our c-TAK cohort has high proportions of neurological involvement and stroke. This is also the first cohort study to describe a distinct group of patients who first presented with refractory KD.
Humans ; Takayasu Arteritis/complications* ; Singapore/epidemiology* ; Male ; Female ; Child ; Adolescent ; Age of Onset ; Mucocutaneous Lymph Node Syndrome/diagnosis* ; Cohort Studies ; Child, Preschool ; Fever/etiology* ; Stroke/epidemiology* ; Retrospective Studies

Humans ; Chikungunya Fever/prevention & control* ; Child ; Chikungunya virus/isolation & purification* ; China/epidemiology*

Based on the pharmacokinetics theory, this study investigated the pharmacokinetic characteristics of albiflorin, paeoniflorin, wogonoside, and wogonin in normal and febrile rats and summarized absorption and elimination rules of Dayuanyin in them to provide reference for further development and clinical application of Dayuanyin. Blood samples were taken from the fundus venous plexus of normal and model rats after intragastric administration of Dayuanyin at different time points. The concentration of each substance in blood was determined by ultra performance liquid chromatography-triple quadrupole mass spectrometry(UPLC-MS/MS) technique at different time points. DAS 2.0, a piece of pharmacokinetics software, was used to calculate the pharmacokinetic parameters of each component. The results show that the 4 components had good linear relationship in their respective ranges, and the results of methodological investigation met the requirements. The pharmacokinetic parameters of C_(max), T_(max), t_(1/2), AUC_(0-t), AUC_(0-∞), and MRT_(0-t) were calculated by the DAS 2.0 non-compartmental model. Compared with those in the normal group, C_(max) and AUC_(0-t) of the 4 components in the model group were significantly increased. There were significant differences in the pharmacokinetic characteristics between the normal and model groups, suggesting that the absorption and elimination of Dayuanyin may be affected by the changes of internal environment of the body in different physiological states.
Animals ; Rats ; Drugs, Chinese Herbal/administration & dosage* ; Male ; Rats, Sprague-Dawley ; Fever/metabolism* ; Tandem Mass Spectrometry ; Chromatography, High Pressure Liquid ; Glucosides/pharmacokinetics* ; Monoterpenes