BACKGROUND AND OBJECTIVE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as the causative agent of COVID-19 has significantly challenged the public health landscape in late 2019. After almost 3 years of the first ever SARS-CoV-2 case, the World Health Organization (WHO) declared the end of this global health emergency in May 2023. Although, despite the subsequent drop of COVID-19 cases, the SARS-CoV-2 infection still exhibited multiple waves of infection, primarily attributed to the appearance of new variants. Five of these variants have been classified as Variants of Concern (VOC): Alpha, Beta, Gamma, Delta, and the most recent, Omicron. Therefore, the development of methods for the timely and accurate detection of viral variants remains fundamental, ensuring an ongoing and effective response to the disease. This study aims to evaluate the feasibility of the application of an in-house approach in genomic surveillance for the detection of SARS-CoV-2 variants using in silico designed primers.

METHODS

The primers used for the study were particularly designed based on conserved regions of certain genes in the virus, targeting distinct mutations found in known variants of SARS-CoV-2. Viral RNA extracts from nasopharyngeal samples (n=14) were subjected to quantitative and qualitative tests (Nanodrop and AGE). Selected samples were then analyzed by RT-PCR and amplicons were submitted for sequencing. Sequence alignment analysis was carried out to identify the prevailing COVID-19 variant present in the sample population.

RESULTS

The study findings demonstrated that the in-house method was able to successfully amplify conserved sequences (spike, envelope, membrane, ORF1ab) and enabled identification of the circulating SARS-CoV-2 variant among the samples. Majority of the samples were identified as Omicron variant. Three out of four designed primers effectively bound into the conserved sequence of target genes present in the sample, revealing the specific SARSCoV-2 variant. The detected mutations characterized for Omicron found in the identified lineages included K417N, S477N, and P681H which were also identified as mutations of interest. Furthermore, identification of the B.1.448 lineage which was not classified in any known variant also provided the potential of the developed in-house method in detecting unknown variants of COVID-19.

CONCLUSION

Among the five VOCs, Omicron is the most prevalent and dominant variant. The in-house direct PCR product sequencing surveillance (DPPSS) method provided an alternative platform for SAR-CoV-2 variant analysis which is accessible and affordable than the conventional diagnostic surveillance methods and the whole genome sequencing. Further evaluation and improvements on the oligonucleotide primers may offer significant contribution to the development of a specific and direct PCRbased detection of new emerging COVID-19 variants.

Sars-cov-2 ; Polymerase Chain Reaction ; Dna Primers ; Oligonucleotide Primers ; Computer Simulation ; Conserved Sequence ; Coronavirus ; Covid-19 ; Disease ; Emergencies ; Evaluation Studies As Topic ; Genes ; Genome ; Global Health ; Health ; Identification (psychology) ; Infection ; Infections ; Membranes ; Methods ; Mutation ; Oligonucleotides ; Organizations ; Population ; Public Health ; Rna ; Rna, Viral ; Sars Virus ; Sequence Alignment ; Severe Acute Respiratory Syndrome ; Syndrome ; Viruses ; Whole Genome Sequencing ; World Health Organization

This paper aimed to explore the intestinal toxicity of Euphoriae Ebracteolata Radix(EER) before and after being processed with Mongolian medicine Hezi Decoction(HZD) and the toxicity-reducing mechanism of this processing method. The intestinal toxicity in rats treated with unprocessed EER and HZD-processed EER extracts via 95% ethanol was compared. The comparison was based on several indicators, including fecal volume, serum diamine oxidase(DAO) and D-lactate(D-LA) levels, the water content of various intestinal segments and their contents, and inflammatory factor levels in intestinal segments. Tandem mass tag(TMT) quantitative proteomics technology was employed to analyze the key proteins associated with changes in intestinal toxicity between unprocessed EER and HZD-processed EER. The results indicated that compared with the blank group, unprocessed EER significantly increased the fecal volume, serum DAO and D-LA levels, water content of the ileal segment and its contents, as well as the release levels of inflammatory factors, including tumor necrosis factor(TNF-α) and interleukin-1 beta(IL-1β) in the ileal segment of rats(P<0.05), indicating that EER can cause diarrhea, increase intestinal permeability, and induce intestinal inflammation. Compared with those in the unprocessed EER group, all indicators in the HZD-processed EER group were significantly reduced(P<0.05). The TMT quantitative proteomics analysis revealed that a total of 6 487 proteins were identified in the rat ileum tissue. Compared to the blank group, 182 proteins exhibited significant changes in the unprocessed EER group, while 907 proteins in the HZD-processed EER group showed significant changes. The intersection of the differential proteins between the two groups identified 38 common proteins. Among them, the protein levels of intestinal barrier tight junction protein claudin3, squalene monooxidase(Sqle), clusterin, Na~+/H~+ exchange regulatory cofactor NHE-RF3(Pdzk1), and Y+L amino acid transporter 1(Slc7a7) exhibited significant changes before and after processing, and these changes were closely related to intestinal barrier function. Compared with the blank group, the expression of claudin3, Pdzk1, and Slc7a7 in the raw product group was significantly down-regulated(P<0.05),while the expression of Sqle and clusterin was significantly up-regulated(P<0.05).Compared with the raw product group, the expression of claudin3, Pdzk1, and Slc7a7 in the processed product group of HZD was significantly up-regulated(P<0.05), while the expression of Sqle and clusterin was significantly down-regulated(P<0.05). Western blot was used to detect the expression level of claudin 3 in the ileum of rats in each group. The results show that compared to that in the blank group, the expression level of claudin 3 in the unprocessed EER group was significantly reduced(P<0.01); compared to that in the unprocessed EER group, the expression level of claudin 3 in the HZD-processed EER group was significantly increased(P<0.01). This finding aligned with the proteomic outcomes, indicating that claudin 3 protein levels could serve as a crucial indicator for intestinal damage caused by EER. In summary, HZD-processed EER can reduce EER's intestinal toxicity, and the primary mechanism for its alleviation of intestinal barrier damage is the regulation of the intestinal barrier tight junction protein claudin 3 and other intestinal-related proteins.
Animals ; Drugs, Chinese Herbal/adverse effects* ; Proteomics ; Rats ; Male ; Rats, Sprague-Dawley ; Intestines/drug effects* ; Intestinal Mucosa/drug effects* ; Tumor Necrosis Factor-alpha/metabolism*

The study aims to explore the herb-drug interaction between Xuefu Zhuyu Decoction(XFZY) and atorvastatin(AT). Reverse transcription polymerase chain reaction(RT-PCR) was used to analyze the transcription levels of proteins related to drug metabolism and transport in LS174T cells, detect the intracellular drug uptake under various substrate concentrations and incubation time, and optimize the model reaction conditions of transporter multidrug resistance protein 1(MDR1)-specific probe Rhodamine 123 and AT to establish a cell model for investigating the human intestinal drug interaction. The cell counting kit-8(CCK-8) method was adopted to evaluate the cytotoxicity of XFZY on LS174T cells. After a single and continuous 48 h culture with XFZY, AT or Rhodamine 123 was added for co-incubation. The effect and mechanism of XFZY on human intestinal absorption of AT were analyzed by measuring the intracellular drug concentrations and transcription levels of related transporters and metabolic enzymes. The results of in vitro experiments show that a single co-culture with a high concentration of XFZY significantly increases the intracellular concentrations of Rhodamine 123 and AT. A high concentration of XFZY co-culture for 48 h increases the AT uptake level, significantly induces the CYP3A4 and UGT1A1 gene expression levels, and inhibits the OATP2B1 gene expression level. To compare with the evaluation results of the in vitro human cell model, the pharmacokinetic experiment of XFZY combined with AT was carried out in rats. Sprague-Dawley(SD) rats were randomly divided into a blank control group and an XFZY group. After 14 days of continuous intragastric administration, AT was given in combination. The liquid chromatography-mass spectrometry(LC-MS)/MS method was used to detect the concentrations of AT and metabolites 2-hydroxyatorvastatin acid(2-HAT), 4-hydroxyatorvastatin acid(4-HAT), atorvastatin lactone(ATL), 2-hydroxyatorvastatin lactone(2-HATL), and 4-hydroxyatorvastatin lactone(4-HATL) in plasma samples, and the pharmacokinetic parameters were calculated. Pharmacokinetic analysis in rats shows that continuous administration of XFZY does not significantly change the pharmacokinetic characteristics of AT in rats, but the AUC_(0-6 h) values of AT and metabolites 2-HAT, 4-HAT, and 2-HATL increase by 21.37%, 14.94%, 12.42%, and 6.68%, respectively. The metabolic rate of the main metabolites shows a downward trend. The study indicates that administration combined with XFZY can significantly increase the uptake level of AT in human intestinal cells and increase the exposure level of AT and main metabolites in rats to varying degrees. The mechanism may be mainly due to the inhibition of intestinal MDR1 transport activity.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Atorvastatin/administration & dosage* ; Humans ; Rats ; Rats, Sprague-Dawley ; Male ; Intestines/cytology* ; Intestinal Mucosa/metabolism* ; Herb-Drug Interactions ; Cytochrome P-450 CYP3A/metabolism* ; Intestinal Absorption/drug effects*

This study investigated the therapeutic effects and mechanisms of Modified Yiyi Fuzi Baijiang Powder on ulcerative colitis(UC) in rats from the perspective of dampness. SD rats were randomly allocated into six groups(n=10): control, model, mesalazine, and Modified Yiyi Fuzi Baijiang Powder at low(3.96 g·kg~(-1)·d~(-1)), medium(7.92 g·kg~(-1)·d~(-1)), and high(15.84 g·kg~(-1)·d~(-1)) doses. UC was induced in all groups except the control by administration with 3% dextran sulfate sodium(DSS) solution for 7 days. The disease activity index(DAI) was recorded, and the colon tissue was collected for analysis. Histopathological changes were assessed by hematoxylin-eosin staining. Serum levels of D-lactic acid(D-LA) and diamine oxidase(DAO) were measured by ELISA. Immunohistochemistry and PCR were employed to evaluate the expression of aquaporins(AQP3, AQP4) and tight junction proteins [zonula occludens-1(ZO-1) and occludin] at both protein and mRNA levels. Compared with the control group, the model group showed an increased DAI scores(P<0.05), intestinal mucosal damage, elevated serum levels of DAO and D-LA(P<0.05), and decreased expression of AQP3, AQP4, ZO-1, and occludin(P<0.05). Treatment with Modified Yiyi Fuzi Baijiang Powder reduced the DAI scores(P<0.05), lowered the serum levels of D-LA and DAO(P<0.05), and upregulated the expression of AQP3, AQP4, ZO-1, and occludin at both protein and mRNA levels compared with the model group. These findings suggest that Modified Yiyi Fuzi Baijiang Powder exerts therapeutic effects on UC by reducing the intestinal mucosal permeability, promoting colonic mucosal repair, and regulating abnormal intestinal water metabolism, which may involve the upregulation of AQP3 and AQP4 expression.
Animals ; Colitis, Ulcerative/genetics* ; Drugs, Chinese Herbal/administration & dosage* ; Rats, Sprague-Dawley ; Rats ; Intestinal Mucosa/metabolism* ; Male ; Aquaporin 3/metabolism* ; Aquaporin 4/metabolism* ; Permeability/drug effects* ; Humans ; Powders ; Intestinal Barrier Function

The gut microbiota regulates intestinal nutrient absorption, participates in modulating host glucolipid metabolism, and contributes to ameliorating glucolipid metabolism disorder. Dysbiosis of the gut microbiota can compromise the integrity of the intestinal mucosal barrier, induce inflammatory responses, and exacerbate insulin resistance and abnormal lipid metabolism in the host. Dangua Humai Oral Liquid, a hospital-developed formulation for regulating glucolipid metabolism, has been granted a national invention patent and demonstrates significant clinical efficacy. This study aimed to investigate the effects of Dangua Humai Oral Liquid on gut microbiota and the intestinal mucosal barrier in a mouse model with glucolipid metabolism disorder. A glucolipid metabolism disorder model was established by feeding mice a high-glucose and high-fat diet. The mice were divided into a normal group, a model group, and a treatment group, with eight mice in each group. The treatment group received a daily gavage of Dangua Humai Oral Liquid(20 g·kg~(-1)), while the normal group and model group were given an equivalent volume of sterile water. After 15 weeks of intervention, glucolipid metabolism, intestinal mucosal barrier function, and inflammatory responses were evaluated. Metagenomics and untargeted metabolomics were employed to analyze changes in gut microbiota and associated metabolic pathways. Significant differences were observed between the indicators of the normal group and the model group. Compared with the model group, the treatment group exhibited marked improvements in glucolipid metabolism disorder, alleviated pathological damage in the liver and small intestine tissue, elevated expression of recombinant claudin 1(CLDN1), occluding(OCLN), and zonula occludens 1(ZO-1) in the small intestine tissue, and reduced serum levels of inflammatory factors lipopolysaccharides(LPS), lipopolysaccharide-binding protein(LBP), interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α). At the phylum level, the relative abundance of Bacteroidota decreased, while that of Firmicutes increased. Lipid-related metabolic pathways were significantly altered. In conclusion, based on the successful establishment of the mouse model of glucolipid metabolism disorder, this study confirmed that Dangua Humai Oral Liquid effectively modulates gut microbiota and mucosal barrier function, reduces serum inflammatory factor levels, and regulates lipid-related metabolic pathways, thereby ameliorating glucolipid metabolism disorder.
Animals ; Gastrointestinal Microbiome/drug effects* ; Mice ; Intestinal Mucosa/microbiology* ; Male ; Drugs, Chinese Herbal/administration & dosage* ; Mice, Inbred C57BL ; Humans ; Glycolipids/metabolism* ; Lipid Metabolism/drug effects* ; Administration, Oral ; Disease Models, Animal

This study compared the differences in intestinal absorption characteristics of eleven active components in Rubus multibracteatus(RM) extract(protocatechuic acid, tiliroside, scutellarin, luteoloside, astragalin, epicatechin, catechin, xanthotoxin, p-coumaric acid, caffeic acid, and apigenin-7-O-glucuronide) between normal rats and inflammatory pain model rats using the in-vitro everted intestinal sac model. The RM extract was administered at absorption concentrations of 25.0, 50.0, and 100.0 mg·mL~(-1). The contents of the eleven components in intestinal absorption solution samples were quantified by ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS), and their cumulative absorption(Q) and absorption rate constant(K_a) were calculated to evaluate the absorption characteristics of these components in normal rats and inflammatory pain model rats. The results show that except for catechin, epicatechin, and caffeic acid, the cumulative absorption-time curves of the other eight components(protocatechuic acid, tiliroside, scutellarin, luteoloside, astragalin, xanthotoxin, p-coumaric acid, and apigenin-7-O-glucuronide) exhibit an upward trend without saturation, with correlation coefficients(R~2) all > 0.9, indicating linear absorption. However, the overall absorption of all components is not dose-dependent with increasing concentration, suggesting that their absorption mechanisms are not solely passive diffusion. In both normal and model rats, the jejunum shows the highest absorption for all components except xanthotoxin. The overall absorption of seven components(excluding protocatechuic acid, caffeic acid, apigenin-7-O-glucuronide, and luteoloside) in normal rats is better than that in model rats across all intestinal segments. These findings indicate that the pathological state of inflammatory pain alters the intestinal absorption of RM extract, and its mechanism needs further investigation.
Animals ; Rats ; Intestinal Absorption/drug effects* ; Male ; Rats, Sprague-Dawley ; Drugs, Chinese Herbal/metabolism* ; Disease Models, Animal ; Pain/metabolism* ; Intestines/drug effects* ; Intestinal Mucosa/metabolism*

OBJECTIVE: To review the research progress and challenges of poly (L-lactic acid) (PLLA) membrane in preventing tendon adhesion. METHODS: The relevant literature at home and abroad in recent years was extensively searched, covering the mechanism of tendon adhesion formation, the adaptation challenge and balancing strategy of PLLA, the physicochemical modification of PLLA anti-adhesion membrane and its application in tendon anti-adhesion. In this paper, the research progress and modification strategies of PLLA membranes were systematically reviewed from the three dimensions of tissue adaptation, mechanical adaptation, and degradation adaptation. RESULTS: The three-dimensional adaptation of PLLA membrane is optimized by combining materials (such as hydroxyapatite, polycaprolactone), structural design (multilayer/gradient membrane), and drug loading (anti-inflammatory drug). The balance between anti-adhesion and pro-healing is achieved, the mechanical adaptation significantly improve, and degradation is achieved (targeting the degradation cycle to 2-4 weeks to cover the tendon repair period). CONCLUSION In the future, it is necessary to identify the optimal balance point of three-dimensional fitness, unify the evaluation criteria and solve the degradation side effects through the co-design of physicochemical modification and drug loading system to break through the bottleneck of clinical translation.
Tissue Adhesions/prevention & control* ; Polyesters/chemistry* ; Humans ; Biocompatible Materials/chemistry* ; Tendons/surgery* ; Membranes, Artificial ; Tendon Injuries/surgery* ; Wound Healing ; Animals ; Durapatite/chemistry*

Necrotizing enterocolitis (NEC) is an intestinal inflammatory and necrotic disease seen in premature infants, and remains the leading cause of death resulted from gastrointestinal diseases in premature infants. The specific pathogenesis of NEC is still unclear. In recent years, a lot of studies have reported that Toll-like receptor 4 (TLR4) plays a key role in the pathogenesis of NEC. TLR4, which is abundantly expressed in intestinal epithelial cells of premature infants, binds to bacterial lipopolysaccharide (LPS) to activate downstream signaling pathways, leading to disruption of intestinal epithelial integrity and bacterial translocation, resulting in intestinal ischemic necrosis and inflammatory responses, which may rapidly progress to severe sepsis, multiple organ dysfunction, and death. This paper reviews the mechanism of TLR4-related signaling pathways in intestinal epithelial injury and inflammatory responses in newborns with NEC, providing a reference to study new therapeutic targets for NEC.
Enterocolitis, Necrotizing/pathology* ; Toll-Like Receptor 4/metabolism* ; Humans ; Infant, Newborn ; Signal Transduction ; Inflammation/metabolism* ; Animals ; Intestines/immunology* ; Intestinal Mucosa/pathology* ; Infant, Premature

PURPOSE: The retear rate of rotator cuff (RC) after surgery is high, and the rapid and functional enthesis regeneration remains a challenge. Whether acellular amniotic membrane (AAM) helps to promote the healing of tendon to bone and which treatment is better are both unclear. The study aims to investigate the effect of AAM on the healing of RC and the best treatment for RC repair. METHODS: Thirty-three Sprague Dawley rats underwent RC transection and repair using microsurgical techniques and were randomly divided into the suturing repair only (SRO) group (n = 11), the AAM overlaying (AOL) group (n = 11), and the AAM interposition (AIP) group (n = 11), respectively. Rats were sacrificed at 4 weeks, then examined by subsequent micro-CT, and evaluated by histologic and biomechanical tests. The statistical analyses of one-way ANOVA or Kruskal-Wallis test were performed using with SPSS 23.0. A p < 0.05 was considered a significant difference. RESULTS: AAM being intervened between tendon and bone (AIP group) or overlaid over tendon to bone junction (AOL group) in a rat model, promoted enthesis regeneration, increased new bone and cartilage generation, and improved collagen arrangement and biomechanical properties in comparison with suturing repair only (SRO group) (AOL vs. SRO, p < 0.001, p = 0.004, p = 0.003; AIP vs. SRO, p < 0.001, p < 0.001, p < 0.001). Compared with the AOL group, the AIP group had better results in micro-CT evaluation, histological score, and biomechanical testing (p = 0 0.039, p = 0.011, p = 0.003, respectively). CONCLUSION In the RC repair model, AAM enhanced regeneration of the tendon to bone junction. This regeneration was more effective when the AAM was intervened at the tendon to bone interface than overlaid above the tendon to bone junction.
Animals ; Rats, Sprague-Dawley ; Rotator Cuff Injuries/surgery* ; Amnion/transplantation* ; Rats ; Wound Healing ; Rotator Cuff/surgery* ; Male ; X-Ray Microtomography ; Tendons/surgery* ; Biomechanical Phenomena

The Masquelet technique, also known as the induced membrane technique, is a surgical technique for repairing large bone defects based on the use of a membrane generated by a foreign body reaction for bone grafting. This technique is not only simple to perform, with few complications and quick recovery, but also has excellent clinical results. To better understand the mechanisms by which this technique promotes bone defect repair and the factors that require special attention in practice, we examined and summarized the relevant research advances in this technique by searching, reading, and analysing the literature. Literature show that the Masquelet technique may promote the repair of bone defects through the physical septum and molecular barrier, vascular network, enrichment of mesenchymal stem cells, and high expression of bone-related growth factors, and the repair process is affected by the properties of spacers, the timing of bone graft, mechanical environment, intramembrane filling materials, artificial membrane, and pharmaceutical/biological agents/physical stimulation.
Humans ; Bone Transplantation/methods* ; Membranes, Artificial ; Bone Regeneration ; Animals