Research progress on the role and mechanism of DNA damage repair in germ cell development.

In the complex and dynamic processes of replication, transcription, and translation of DNA molecules, a large number of replication errors or damage can occur which lead to obstacles in the development process of germ cells and result in a decreased reproductive rate. DNA damage repair has attracted widespread attention due to its important role in the maintenance and regulation of germ cells. This study reports on a systematic review of the role and mechanism of DNA damage repair in germline development. First, the causes, detection methods, and repair methods of DNA damage, and the mechanism of DNA damage repair are summarized. Second, a summary of the causes of abnormal DNA damage repair in germ cells is introduced along with common examples, and the relevant effects of germ cell damage. Third, we introduce the application of drugs related to DNA damage repair in the treatment of reproductive diseases and related surgical treatment of abnormal DNA damage, and summarize various applications of DNA damage repair in germ cells. Finally, a summary and discussion is given of the current deficiencies in DNA damage repair during germ cell development and future research development. The purpose of this paper is to provide researchers engaged in relevant fields with a further systematic understanding of the relevant applications of DNA damage repair in germ cells and to gain inspiration from it to provide new research ideas for related fields.

Current state of knowledge on intelligent-response biological and other macromolecular hydrogels in biomedical engineering: A review.

Because intelligent hydrogels have good biocompatibility, a rapid response, and good degradability as well as a stimulus response mode that is rich, hydrophilic, and similar to the softness and elasticity of living tissue, they have received widespread attention and are widely used in biomedical engineering. In this article, we conduct a systematic review of the use of smart hydrogels in biomedical engineering. First, we introduce the properties and applications of hydrogels and compare the similarities and differences between traditional hydrogels and smart hydrogels. Secondly, we summarize the intelligent hydrogel types, the mechanisms of action used by different hydrogels, and the materials for preparing different types of hydrogels, such as the materials for the preparation of temperature-responsive hydrogels, which mainly include gelatin, carrageenan, agarose, amylose, etc.; summarize the morphologies of different hydrogels, such as films, fibers and microspheres; and summarize the application of smart hydrogels in biomedical engineering, such as for the delivery of proteins, antibiotics, deoxyribonucleic acid, etc. Finally, we summarize the shortcomings of current research and present future prospects for smart hydrogels. The purpose of this paper is to provide researchers engaged in related fields with a systematic review of the application of intelligent hydrogels in biomedical engineering. We hope that they will get some inspiration from this work to provide new directions for the development of related fields.

Genetic Variation Analysis of Porcine Circovirus Type 4 in South China in 2019 to 2021.

Porcine circovirus type 4 (PCV4) is a novel virus associated with porcine dermatitis and nephropathy syndrome (PDNS)-like signs identified firstly in China in 2019. However, the details of the molecular epidemiology of PCV4 are unclear at this time. A total of forty-two related sequences were selected from the GenBank database to explore the spread of PCV4 and its rule in genetic evolution. Of the selected strains, 41 were from south China in 2019 to 2021 and the other was a foreign representative strain. Phylogenetic tree construction, nucleotide and amino acid (aa) sequence alignment, gene recombination and antigen structure prediction were performed on the collected sequences using bioinformatics softwares. The 42 PCV4 strains were divided into two subgenotypes: PCV4a (35/42) and PCV4b (7/42), according to the constructed genetic evolution tree. PCV4a is the main epidemic strain, and it can be further divided into two different gene clusters: PCV4a-1 (22/35) and PCV4a-2 (13/35). The pairwise comparison analysis showed that the complete genome sequence similarity of the 42 PCV4 strains ranged between 97.9% and 100%, and the aa sequences of the Cap proteins of 42 PCV4 strains had three major heterogenic or hypervariable regions-27-28, 96 and 212-all located near the antigenic epitope of the Cap protein. The results of this study can provide some basis for further studying the spread and epidemic growth of PCV4, and the prevention and control of PCV4 infection in China.

Progress in the application of sustained-release drug microspheres in tissue engineering.

Sustained-release drug-loaded microspheres provide a long-acting sustained release, with targeted and other effects. There are many types of sustained-release drug microspheres and various preparation methods, and they are easy to operate. For these reasons, they have attracted widespread interest and are widely used in tissue engineering and other fields. In this paper, we provide a systematic review of the application of sustained-release drug microspheres in tissue engineering. First, we introduce this new type of drug delivery system (sustained-release drug carriers), describe the types of sustained-release drug microspheres, and summarize the characteristics of different microspheres. Second, we summarize the preparation methods of sustained-release drug microspheres and summarize the materials required for preparing microspheres. Third, various applications of sustained-release drug microspheres in tissue engineering are summarized. Finally, we summarize the shortcomings and discuss future prospects in the development of sustained-release drug microspheres. The purpose of this paper was to provide a further systematic understanding of the application of sustained-release drug microspheres in tissue engineering for the personnel engaged in related fields and to provide inspiration and new ideas for studies in related fields.

Factors Defining the Development of Severe Illness in Patients with COVID-19: A Retrospective Study.

OBJECTIVE: Early triage of patients with coronavirus disease 2019 (COVID-19) is pivotal in managing the disease. However, studies on the clinical risk score system of the risk factors for the development of severe disease are limited. Hence, we conducted a clinical risk score system for severe illness, which might optimize appropriate treatment strategies. METHODS: We conducted a retrospective, single-center study at the JinYinTan Hospital from January 24, 2020 to March 31, 2020. We evaluated the demographic, clinical, and laboratory data and performed a 10-fold cross-validation to split the data into a training set and validation set. We then screened the prognostic factors for severe illness using the least absolute shrinkage and selection operator (LASSO) and logistic regression, and finally conducted a risk score to estimate the probability of severe illness in the training set. Data from the validation set were used to validate the score. RESULTS: A total of 295 patients were included. From 49 potential risk factors, 3 variables were measured as the risk score: neutrophil to lymphocyte ratio ( OR, 1.27; 95% CI, 1.15-1.39), albumin ( OR, 0.76; 95% CI, 0.70-0.83), and chest computed tomography abnormalities ( OR, 2.01; 95% CI, 1.41-2.86) and the AUC of the validation cohort was 0.822 (95% CI, 0.7667-0.8776). CONCLUSION: This report may help define the potential of developing severe illness in patients with COVID-19 at an early stage, which might be related to the neutrophil to lymphocyte ratio, albumin, and chest computed tomography abnormalities.

Clinical trial with traditional Chinese medicine intervention ''tonifying the kidney to promote liver regeneration and repair by affecting stem cells and their microenvironment'' for chronic hepatitis B-associated liver failure.

AIM: To study the clinical efficacy of traditional Chinese medicine (TCM) intervention "tonifying the kidney to promote liver regeneration and repair by affecting stem cells and their microenvironment" ("TTK") for treating liver failure due to chronic hepatitis B. METHODS: We designed the study as a randomized controlled clinical trial. Registration number of Chinese Clinical Trial Registry is ChiCTR-TRC-12002961. A total of 144 patients with liver failure due to infection with chronic hepatitis B virus were enrolled in this randomized controlled clinical study. Participants were randomly assigned to the following three groups: (1) a modern medicine control group (MMC group, 36 patients); (2) a "tonifying qi and detoxification" ("TQD") group (72 patients); and (3) a "tonifying the kidney to promote liver regeneration and repair by affecting stem cells and their microenvironment" ("TTK") group (36 patients). Patients in the MMC group received general internal medicine treatment; patients in the "TQD" group were given a TCM formula "tonifying qi and detoxification" and general internal medicine treatment; patients in the "TTK" group were given a TCM formula of "TTK" and general internal medicine treatment. All participants were treated for 8 wk and then followed at 48 wk following their final treatment. The primary efficacy end point was the patient fatality rate in each group. Measurements of various virological and biochemical indicators served as secondary endpoints. The one-way analysis of variance and the t-test were used to compare patient outcomes in the different treatment groups. RESULTS: At the 48-wk post-treatment time point, the patient fatality rates in the MMC, "TQD", and "TTK" groups were 51.61%, 35.38%, and 16.67%, respectively, and the differences between groups were statistically significant (P < 0.05). However, there were no significant differences in the levels of hepatitis B virus DNA or prothrombin activity among the three groups (P > 0.05). Patients in the "TTK" group had significantly higher levels of serum total bilirubin compared to MMC subjects (339.40 µmol/L ± 270.09 µmol/L vs 176.13 µmol/L ± 185.70 µmol/L, P = 0.014). Serum albumin levels were significantly increased in both the "TQD" group and "TTK" group as compared with the MMC group (31.30 g/L ± 4.77 g/L, 30.72 g/L ± 2.89 g/L vs 28.57 g/L ± 4.56 g/L, P < 0.05). There were no significant differences in levels of alanine transaminase among the three groups (P > 0.05). Safety data showed that there was one case of stomachache in the "TQD" group and one case of gastrointestinal side effect in the "TTK" group. CONCLUSION: Treatment with "TTK" improved the survival rates of patients with liver failure due to chronic hepatitis B. Additionally, liver tissue was regenerated and liver function was restored.

[Relationship between physical activity and the incidence of metabolic syndrome in Chinese adults: a prospective cohort study].

OBJECTIVE: To investigate the association between physical activity (PA) and the incidence of metabolic syndrome (MS) in Chinese adults. METHODS: Data on PA and other variables were obtained at the baseline examination of China Multi-center study of Cardiovascular Epidemiology in 1998 and of International Collaborative study of Cardiovascular Disease in Asia(InterASIA) during 2000 - 2001. Follow-up study was conducted in 2007 - 2008. A total of 11 512 Chinese adults aged 35 - 74 years (5563 men and 5949 women) were included in the final data analysis. Information on demographics, PA, smoking and alcohol consumption were obtained and components of MS were examined. Participants were divided into four groups according to quartile of total metabolic equivalent (MET) values per day. In addition, subjects were grouped into the following categories according to occupational PA: inactive, light, moderate and vigorous. Binary logistic model was used to examine the association between PA and the incidence of MS. RESULTS: A total of 2527 cases with MS were documented during an average following up of 8.1 years. The annual incidence rate of MS was 2.71% (2527/93 178.68). After multivariate logistic regression analysis, compared with participants with total PA volume < 32.0 MET×h×d(-1) (annual incidence rate was 3.19% (697/21 830.74)), the RR (95%CI) value of participants with total PA volume during 32.00 - 37.85, 37.86 - 52.29, and ≥ 52.30 MET×h×d(-1) was 1.05(0.92 - 1.19), 0.98(0.86 - 1.12), and 0.68(0.59 - 0.80), respectively (χ(2)trend = 34.23, P < 0.05), with corresponding annual incidence rates of 2.82% (690/24 504.25), 2.73% (661/24 179.36) and 2.11% (479/22 664.33). In addition, compared to inactive occupational PA (annual incidence rate was 2.76% (402/14 588.33)), the corresponding RR (95%CI) value was 0.80 (0.69 - 0.92), 0.70 (0.59 - 0.82), and 0.54 (0.45 - 0.65) (χ(2)trend = 42.34, P < 0.05), and the annual incidence rates were 2.86% (648/22 663.41), 2.40% (455/18 956.14) and 1.89% (344/18 173.86) in participants with light, moderate and vigorous occupational PA, respectively. CONCLUSION: Both increased total PA volume and occupational PA intensity are significantly associated with decreased risk of incidence of MS.