Objective:To understand the pathogenic situation of hand, foot and mouth disease (HFMD) in Linyi City, and to analyze the gene characteristics of Coxsackievirus A10 complete VP1 region.Methods:The samples of HFMD cases from Linyi City in 2023 were tested for typing and strain isolation, and the VP1 gene of CV-A10 isolate was amplified and sequenced. The obtained sequences were compared with those in the NCBI database, and the phylogenetic tree was constructed for gene characteristics and molecular epidemiological analysis.Results:In 2023, a total of 861 samples of HFMD were collected, and 594 (68.99%) were positive for nucleic acid tests. The male to female ratio of positive cases was 1.56∶1. Children under 5 years old accounted for 81.65%, and the highest incidence season was from June to August (83.84%). CV-A6 was the main pathogen (84.51%), followed by CV-A10 (9.93%). The nucleotide and amino acid homology of VP1 gene sequence among 13 isolates were 93.29%-100.00% and 97.65%-100.00%, respectively. The nucleotide and amino acid homology with AF081300-Kowalik/USA/1950 was lower (75.95%-76.62%, 91.72%-92.41%). The amino acid and nucleotide homology with C2c was the highest (94.28%-96.76%, 98.28%-100.00%), and the genetic distance was the closest (0.04-0.06). Amino acid site variation analysis showed that compared with the prototype strain AF081300-Kowalik/USA/1950, the isolates had more site variation, while only some isolates had I80V, E141K, P147S, T219I, E240K and V261I mutations compared with the representative strain C2c. The genetic evolution tree showed that the isolates were all in the same clade as the C2c representative strains, and they all belonged to the C2c genotype, and the isolates were further divided into two smaller clades.Conclusions:In 2023, CV-A6 was the main pathogen of HFMD in Linyi City, followed by CV-A10. All CV-A10 isolates were C2c genotypes and can be divided into two evolutionary clades. Continuous monitoring and genetic characterization of CV-A10 should be strengthened.

Animals ; Antibodies, Neutralizing/biosynthesis* ; Antibodies, Viral/biosynthesis* ; Body Weight/immunology* ; COVID-19/virology* ; Disease Models, Animal ; Disease Progression ; Humans ; Immunohistochemistry ; Lung/virology* ; Male ; Mesocricetus ; Nasal Cavity/virology* ; RNA, Viral/immunology* ; SARS-CoV-2/pathogenicity* ; Severity of Illness Index ; Viral Load

In vitro diagnosis (IVD) is an important source of clinical diagnostic information, and provides an important decision basis for disease prevention, diagnosis and treatment. IVD is a necessary tool for promoting graded diagnosis and treatment, realizing precision medicine, constructing a "Healthy China" and responding to major public health emergencies. Combining the great progress made in the development of in vitro diagnostics in China and the shortcomings and weaknesses faced by it, this article analyzed the demand for IVD, policy support, technical and industrial development trends, and the ways to accelerate the industrialization development, aiming to promote the development and improvement of IVD in China.

With the advantages of low immunogenicity and long half-life, human monoclonal antibody has become an indispensable biological agent in vivo. Immortalization of human B cells is a potential and effective method to obtain natural human antibody library, which can provide a rich source for the preparation of human monoclonal antibodies. As there are urgent problems to be solved in each platform, the preparation of antibodies based on human B cell immortalization is still limited to the laboratory research stage. At present, there is a lack of a systematic review to clarify the advantages and disadvantages of the existing human B cell immortalization antibody preparation platform and its feasibility analysis. This paper reviews the research on the preparation of human monoclonal antibody based on human B cells immortalization, and describes an in vitro cell culture method, in which hCD40L vesicles are used instead of feeder cells, in order to provide references for the further development of human monoclonal antibody preparation technology.
Antibodies, Monoclonal ; B-Lymphocytes ; Cell Culture Techniques ; Humans

Rotavirus (RV) is one of the leading causes of acute gastroenteritis in infants and young animals worldwide. Rotavirus infection has obvious species specificity and mainly causes diarrhea in infants and young animals. The host innate responses suppress the infection and replication of rotavirus through activating multiple signaling pathways. Meanwhile, rotavirus also antagonizes the innate immune responses in various ways. This article reviewed the mechanisms of host innate immune responses to rotavirus infection and the antagonistic mechanism of rotavirus against host innate immunity with a view to providing reference for the development of therapeutic drugs and the prevention of rotavirus infection.

Targeted protein degradation (TPD) technology facilitates specific and efficient degradation of disease-related proteins through hijacking the two major protein degradation systems in mammalian cells: ubiquitin-proteasome system and lysosome pathway. Compared with traditional small molecule-inhibitors, TPD-based drugs exhibit the characteristics of a broader target spectrum. Compared with techniques interfere with protein expression on the gene and mRNA level, TPD-based drugs are target-specific, efficaciously rapid, and not constrained by post-translational modification of proteins. In the past 20 years, various TPD-based technologies have been developed. Most excitingly, two TPD-based therapeutic drugs have been approved by FDA for phase Ⅰ clinical trials in 2019. Despite of the early stage characteristics and various obstructions of the TPD technology, it could serve as a powerful tool for the development of novel drugs. This review summarizes the advances of different degradation systems based on TPD technologies and their applications in disease therapy. Moreover, the advantages and challenges of various technologies were discussed systematically, with the aim to provide theoretical guidance for further application of TPD technologies in scientific research and drug development.
Animals ; Proteasome Endopeptidase Complex/metabolism* ; Protein Processing, Post-Translational ; Proteins/metabolism* ; Proteolysis ; Technology

Point-of-care testing (POCT) is a test method performed on the sampling site or patient bedside. Accurate results can be achieved rapidly by the application of portable analytical instruments and compatible reagents. It has been widely used in the field of in vitro diagnosis (IVD). Paper-based microfluidics technology has great potential in developing POCT due to its advantages in low cost, simple operation, rapid detection, portable equipment, and unrestricted application conditions. In recent years, the development of paper-based microfluidic technology and its integration with various new technologies and methods have promoted the substantial development of POCT technology and methods. The classification and characteristic of the paper are summarized in this review. Paper-based microfluidic sample pretreatment methods, the flow control in the process of reaction and the signal detecting and analyzing methods for the testing results are introduced. The research progress of various kinds of microfluidic paper-based analytical devices (μPADs) toward POCT in recent years is reviewed. Finally, remaining problems and the future prospects in POCT application of paper-based microfluidics are discussed.
Diagnostic Tests, Routine ; methods ; Humans ; Microfluidic Analytical Techniques ; instrumentation ; Paper ; Point-of-Care Testing

With the requirements of early diagnosis, biomarker development and functional definition, the challenge of sensitivity of immunoassay has become increasingly prominent. How to improve it to break the bottleneck has become a major challenge in the field of bioassays. Amplifying the immunosignal is the most direct method to improve detection sensitivity. Biotin-avidin system (BAS), tyramide signal amplification (TSA) and immuno-polymerase chain reaction (Im-PCR) are the most classic signal amplification techniques which significantly improved the sensitivity of immunoassays. In recent years, studies have confirmed that the sensitivity of immunoassays can be further increased by approximately three orders of magnitude with the invention of techniques including catalyzed reporter deposition-based signal amplification, nanotechnologies-based signal amplification and hybridization chain reaction-based signal amplification. Herein, we will summarize the techniques that have been developed in recent years for amplifying the signals of immunodetection and comparatively analyze their advantages and disadvantages in order to provide reference for the developed techniques transformed to clinical application and further research on ultrasensitive immunoassays.

The convective polymerase chain reaction (CCPCR) uses the principle of thermal convection to allow the reagent to flow in the test tube and achieve the purpose of amplification by the temperature difference between the upper and lower portions of the test tube. In order to detect the amplification effect in real time, we added a fluorophore to the reagent system to reflect the amplification in real time through the intensity of fluorescence. The experimental results show that the fluorescence curve conforms to the S-type trend of the amplification curve, but there is a certain jitter condition due to the instability of the thermal convection, which is not conducive to the calculation of the cycle threshold (CT value). In order to solve this problem, this paper uses the dynamic method, using the double S-type function model to fit the curve, so that the fluorescence curve is smooth and the initial concentration of the nucleic acid can be deduced better to achieve the quantitative purpose based on the curve. At the same time, the PSO+ algorithm is used to solve the double s-type function parameters, that is, particle swarm optimization (PSO) algorithm combined with Levenberg-Marquardt, Newton-CG and other algorithms for curve fitting. The proposed method effectively overcoms PSO randomness and the shortcoming of traditional algorithms such as Levenberg-Marquardt and Newton-CG which are easy to fall into the local optimal solution. The of the data fitting result can reach 0.999 8. This study is of guiding significance for the future quantitative detection of real-time fluorescent heat convection amplification.
Algorithms ; Fluorescence ; Fluorescent Dyes ; Polymerase Chain Reaction

Reverse genetics approaches can directly manipulate the genome of virus at the gene level, making it possible to quickly, directly and thoroughly study the mechanisms of virus replication and pathogenesis. At present, many viruses of the family Reoviridae, such as mammalian orthoreovirus ( MRV) and bluetongue virus ( BTV) , have made great progress in basic viral research using the powerful tool of re-verse genetics. However, for members of the genus Rotavirus in the family Reoviridae, progress in the con-struction of reverse genetic systems has been slow. The remarkable reverse genetics system based on helper-viruses was established in 2006, and it was not until 2017 that the entirely plasmid-based reverse genetics system was successfully established. This paper briefly reviewed the development of reverse genetics systems for rotavirus and prospected the direction for future research in order to provide technical support for acceler-ating the basic research on mechanisms of rotavirus infection.