Renal fibrosis is the common pathological endpoint of many forms of chronic kidney disease (CKD), yet the mechanisms determining effective repair versus persistent fibrotic remodeling remain incompletely understood. Peritubular capillaries (PTCs) are not merely passive targets of fibrotic injury, but form a dynamic vascular microenvironment linking regional perfusion, oxygen delivery, tubular metabolism, endothelial barrier integrity, pericyte support, immune-cell trafficking, and extracellular matrix (ECM) remodeling. We propose that PTC abnormalities should not be interpreted simply as reduced capillary density, but as a multidimensional disturbance of microvascular structure and function. Structural vascular preservation does not necessarily indicate effective microcirculation: anatomically detectable capillaries may still exhibit impaired perfusion, barrier dysfunction, abnormal endothelial-pericyte interactions, disturbed oxygen metabolism, or reduced network connectivity. Conversely, increased angiogenesis does not necessarily signify successful vascular repair if vessels remain immature, poorly perfused, or inadequately integrated into the existing network. To organize these abnormalities, we conceptualize PTC remodeling into four predominant but nonexclusive states: endothelial barrier disruption with inflammatory adhesion; endothelial-pericyte uncoupling with no-reflow; dysregulated angiogenesis with network simplification; and capillary rarefaction with fibrotic matrix locking. These states are not sequential stages of CKD. They may coexist within the same kidney, overlap within the same anatomical region, and vary with disease etiology, injury phase, vascular compartment, and treatment exposure. We further propose six dimensions for evaluating PTC status—structural presence, functional perfusion, barrier integrity, pericyte coupling, oxygen metabolism, and network connectivity—so that vascular quantity, function, and reparative capacity are assessed separately rather than inferred from a single endothelial marker or capillary-density measurement. Mechanistically, these states converge on a bidirectional microvascular-fibrotic feedback loop. Barrier disruption facilitates leukocyte recruitment and alters vascular paracrine signaling. Endothelial-pericyte uncoupling compromises capillary stability, whereas abnormal pericyte contraction may increase local vascular resistance and contribute to no-reflow before overt capillary loss. Dysregulated angiogenesis may generate vessels that fail to mature or connect to an effective perfusion network. Progressive capillary rarefaction compromises oxygen delivery, while sustained tubular transport demand and mitochondrial dysfunction may aggravate regional oxygen supply-demand mismatch. Injured tubules, immune cells, endothelial cells, pericytes, and fibroblasts communicate through soluble mediators, extracellular vesicles, direct cell contact, and cell-matrix signaling. Importantly, fibrosis is not merely a downstream consequence of microvascular injury. Altered ECM may increase diffusion distance, modify mechanotransduction, impair endothelial survival and migration, and restrict capillary reopening and regeneration. We use the term matrix locking to describe this sustained constraint on vascular repair, while emphasizing that current evidence does not establish irreversible disease in humans. This framework also has therapeutic implications. PTC-directed treatment should not be reduced to increasing vessel number or uniformly promoting angiogenesis. Instead, intervention should be matched to the dominant and potentially reversible abnormality: preserving endothelial barrier function; restoring endothelial-pericyte stability and reducing pathological microvascular resistance; normalizing angiogenesis so that vascular growth is accompanied by maturation, barrier competence, network integration, and effective perfusion; and, in advanced rarefaction, relieving matrix-related constraints while supporting vascular regeneration. The context- and time-dependent effects of signaling through VEGF, Tie2, PDGF-B/PDGFRβ, eNOS/NO, and related pathways indicate that the same molecular signal may exert different effects depending on disease context and timing. Therapeutic efficacy should therefore be evaluated by restoration of effective microcirculation and tissue function rather than by isolated molecular changes or capillary counts alone. Despite increasing mechanistic evidence, the translational basis for this framework remains limited. Most causal and interventional data derive from animal or cell models, whereas human evidence is largely limited to pathological observations, patient-sample associations, and prognostic studies. Currently available circulating and urinary candidate biomarkers generally lack sufficient specificity for PTC injury or state assignment, and no standardized quantitative thresholds have been externally validated. The four-state model should therefore be regarded as a hypothesis-generating analytical framework rather than a clinicopathological classification system. Future studies should integrate spatially resolved tissue phenotyping, blood and urine biomarkers, and dynamic microcirculatory assessment in longitudinal cohorts. They should test reproducibility, assess prognostic value beyond conventional pathology, estimated glomerular filtration rate, and proteinuria, and determine whether changes in PTC status precede or mediate therapeutic benefit. Linking reproducible microvascular phenotypes to defined mechanisms, treatment response, and long-term renal outcomes will be essential to determine whether state-directed assessment and restoration of the PTC microenvironment can ultimately inform patient stratification and therapeutic decision-making.

OBJECTIVE: Patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection frequently develop central nervous system damage, yet the mechanisms driving this pathology remain unclear. This study investigated the primary pathways and key factors underlying brain tissue damage induced by the SARS-CoV-2 beta variant (lineage B.1.351). METHODS: K18-hACE2 and C57BL/6 mice were intranasally infected with the SARS-CoV-2 beta variant. Viral replication, pathological phenotypes, and brain transcriptomes were analyzed. Gene Ontology (GO) analysis was performed to identify altered pathways. Expression changes of host genes were verified using reverse transcription-quantitative polymerase chain reaction and Western blot. RESULTS: Pathological alterations were observed in the lungs of both mouse strains. However, only K18-hACE2 mice exhibited elevated viral RNA loads and infectious titers in the brain at 3 days post-infection, accompanied by neuropathological injury and weight loss. GO analysis of infected K18-hACE2 brain tissue revealed significant dysregulation of genes associated with innate immunity and antiviral defense responses, including type I interferons, pro-inflammatory cytokines, Toll-like receptor signaling components, and interferon-stimulated genes. Neuroinflammation was evident, alongside activation of apoptotic and pyroptotic pathways. Furthermore, altered neural cell marker expression suggested viral-induced neuroglial activation, resulting in caspase 4 and lipocalin 2 release and disruption of neuronal molecular networks. CONCLUSION These findings elucidate mechanisms of neuropathogenicity associated with the SARS-CoV-2 beta variant and highlight therapeutic targets to mitigate COVID-19-related neurological dysfunction.
Animals ; COVID-19/genetics* ; Mice ; Brain/metabolism* ; Apoptosis ; Mice, Inbred C57BL ; SARS-CoV-2/physiology* ; Pyroptosis ; Gene Expression Profiling ; Transcriptome ; Male ; Female

Objective To analyze the characteristics of intestinal flora of personnel stationed on an island,so as to lay the foundation for maintaining the intestinal microecological balance of personnel stationed on island and provide accurate medical security.Methods Several subjects stationed on an island and several subjects from coastal areas were enrolled by random and sampling method,and their fecal samples were sequenced by 16S rRNA high-throughput sequencing.Diversity and composition of gut microbiota in 2 cohorts of personnel were compared.Results Alpha diversity analysis of intestinal flora showed that the abundance of intestinal flora in subjects stationed on the island was significantly higher than that of subjects from coastal areas.Beta diversity analysis indicated significant differences in the composition of intestinal microbial communities between the subjects stationed on the island and those from coastal areas(P=0.001).The abundance of the Bacteroidota in the intestinal tract of subjects stationed on the island was significantly lower than that of subjects from coastal areas(30.8%vs 48.3%,P＜0.001),while the abundance of the Proteobacteria was significantly higher than that of subjects from coastal areas(28.3%vs 10.2%,P＜0.001).After multiple hypothesis testing correction,it was found that the abundance of the Bacteroides,Roseburia,Alistipes,and Parabacteroides in the intestines of subjects stationed on the island decreased significantly,while the abundance of the Prevotella,Escherichia-Shigella,Citrobacter,and Eubacterium_coprostanoligenes increased significantly.Conclusion The special environment of islands affects the characteristics of intestinal flora of personnel,and the intestinal microecological health needs precise maintenance.

Objective To investigate the detection rate and related influencing factors of gastrointestinal diseases in grass-roots personnel.Methods A total of 481 grass-roots personnel were enrolled and examined by magnetic-controlled capsule endoscopy(MCCE).Multivariate logistic regression were used to analyze the influencing factors of gastrointestinal diseases detected by MCCE.Results All personnel completed MCCE,and gastrointestinal diseases were detected in 154(32.0%)cases,including 106 cases of erosive gastritis,25 cases of chronic atrophic gastritis,17 cases of digestive tract polyp,16 cases of gastric ulcer,5 cases of reflux esophagitis,4 cases of cardia,1 case of duodenitis,and 1 case of enteritis.Gastrointestinal diseases was correlated with special operation posts,long-term tasks within recent 6 months,abdominal distension,belching,nausea and vomiting,diarrhea and other symptoms(all P＜0.05).Multivariate logistic regression analysis showed that the risk factors of gastrointestinal diseases were working in special operation posts,performing long tasks within 6 months,belching,nausea and vomiting symptoms(all P＜0.05).Conclusion The overall detection rate of gastrointestinal diseases(mainly acid related diseases)is relatively high,and its incidence is closely related to working in special operation posts and performing long-term tasks within recent 6 months.Personnel working in special operation posts should be more alert to gastrointestinal diseases.Gastrointestinal symptoms have reference value for the prediction of lesions,but more attention should be paid to the identification of functional gastrointestinal diseases with endoscopy.

Investigating the correlation between micronucleus formation and male infertility has the potential to improve clinical diagnosis and deepen our understanding of pathological progression. Our study enrolled 2252 male patients whose semen was analyzed from March 2023 to July 2023. Their clinical data, including semen parameters and age, were also collected. Genetic analysis was used to determine whether the sex chromosome involved in male infertility was abnormal (including the increase, deletion, and translocation of the X and Y chromosomes), and subsequent semen analysis was conducted for clinical grouping purposes. The participants were categorized into five groups: normozoospermia, asthenozoospermia, oligozoospermia, oligoasthenozoospermia, and azoospermia. Patients were randomly selected for further study; 41 patients with normozoospermia were included in the control group and 117 patients with non-normozoospermia were included in the study group according to the proportions of all enrolled patients. Cytokinesis-block micronucleus (CBMN) screening was conducted through peripheral blood. Statistical analysis was used to determine the differences in micronuclei (MNi) among the groups and the relationships between MNi and clinical data. There was a significant increase in MNi in infertile men, including those with azoospermia, compared with normozoospermic patients, but there was no significant difference between the genetic and nongenetic groups in azoospermic men. The presence of MNi was associated with sperm concentration, progressive sperm motility, immotile spermatozoa, malformed spermatozoa, total sperm count, and total sperm motility. This study underscores the potential utility of MNi as a diagnostic tool and highlights the need for further research to elucidate the underlying mechanisms of male infertility.
Humans ; Male ; Infertility, Male/genetics* ; Adult ; Micronucleus Tests ; Semen Analysis ; Oligospermia/genetics* ; Azoospermia/genetics* ; Chromosome Aberrations ; Sperm Count ; Micronuclei, Chromosome-Defective ; Middle Aged

OBJECTIVES: To study the incidence and disease burden of congenital birth defects in children under five in China from 1990 to 2021 and to predict the incidence of congenital birth defects in this population from 2022 to 2036, providing a reference for the prevention of congenital birth defects in children. METHODS: Using the Global Burden of Disease Study 2021 (GBD 2021) database, the incidence and disability-adjusted life years (DALY) were employed to describe the disease burden. The Joinpoint regression model was used to analyze the trends in incidence and DALY rates of congenital birth defects in children under five. A grey prediction model GM(1,1) was applied to fit the trend of incidence rates of congenital birth defects in this age group and to predict the incidence from 2022 to 2036. RESULTS: In 2021, the incidence rate of congenital birth defects among children under five in China was 737.28 per 100 000. Among these, congenital musculoskeletal and limb deformities had the highest incidence rate at 307.15 per 100 000, followed by congenital heart defects (223.53 per 100 000), congenital urinary and genital tract malformations (74.99 per 100 000), and congenital gastrointestinal malformations (62.61 per 100 000). From 1990 to 2021, the incidence rate and DALY rate of congenital birth defects in children under five in China decreased at an average annual rate of 1.73% and 5.42%, respectively. The prediction analysis indicated a decreasing trend in the incidence of congenital birth defects among children under five in China from 2022 to 2036, with the incidence rate dropping from 892.36 per 100 000 in 2022 to 783.35 per 100 000 in 2036. CONCLUSIONS The incidence and disease burden of congenital birth defects in children under five in China showed a significant declining trend from 1990 to 2021. It is predicted that this incidence will continue to decrease until 2036.
Humans ; Congenital Abnormalities/epidemiology* ; China/epidemiology* ; Incidence ; Infant ; Infant, Newborn ; Child, Preschool ; Female ; Male ; Forecasting ; Disability-Adjusted Life Years

OBJECTIVE: To investigate the effects of acupuncture on the neurotransmitter levels and gut microbiota in a mouse model of Tourette syndrome (TS). METHODS: Thirty-six male C57/BL6 mice were randomly divided into 4 groups using a random number table method: 3,3'-iminodipropionitrile (IDPN) group, control group, acupuncture group, and tiapride group, with 9 mice in each group. In the IDPN group, acupuncture group, and tiapride group, mice received daily intraperitoneal injections of IDPN (300 mg/kg body weight) for 7 consecutive days to induce stereotyped behaviors. Subsequently, in the acupuncture intervention group, standardized acupuncture treatment was administered for 14 consecutive days to IDPN-induced TS model mice. The selected acupoints included Baihui (DU 20), Yintang (DU 29), Waiguan (SJ 5), and Zulinqi (GB 41). In the tiapride group, mice were administered tiapride (50 mg/kg body weight) via oral gavage daily for 14 consecutive days. The control group, IDPN group, and acupuncture group received the same volume of saline orally for 14 consecutive days. Stereotypic behaviors were quantified through behavioral assessments. Neurotransmitter levels, including dopamine (DA), glutamate (Glu), and aspartate (ASP) in striatal tissue were measured using enzyme-linked immunosorbent assay. Dopamine transporter (DAT) expression levels were additionally quantified through quantitative polymerase chain reaction (qPCR). Gut microbial composition was analyzed through 16S ribosomal RNA gene sequencing, while metabolic profiling was conducted using liquid chromatography-mass spectrometry (LC-MS). RESULTS: Acupuncture administration significantly attenuated stereotypic behaviors, concurrently reducing striatal levels of DA, Glu and ASP concentrations while upregulating DAT expression compared with untreated TS controls (P<0.05 or P<0.01). Comparative analysis identified significant differences in Muribaculaceae (P=0.001), Oscillospiraceae (P=0.049), Desulfovibrionaceae (P=0.001), and Marinifilaceae (P=0.014) following acupuncture intervention. Metabolomic profiling revealed alterations in 7 metabolites and 18 metabolic pathways when compared to the TS mice, which involved various amino acid metabolisms associated with DA, Glu, and ASP. CONCLUSIONS Acupuncture demonstrates significant modulatory effects on both central neurotransmitter systems and gut microbial ecology, thereby highlighting its dual therapeutic potential for TS management through gut-brain axis regulation.
Animals ; Tourette Syndrome/metabolism* ; Gastrointestinal Microbiome ; Neurotransmitter Agents/metabolism* ; Acupuncture Therapy ; Male ; Mice, Inbred C57BL ; Mice

Vascular damage plays a significant role in the onset and progression of Alzheimer's disease (AD). However, the precise molecular mechanisms underlying the induction of neuronal injury by vascular damage remain unclear. The present study aimed to examine the impact of fibrinogen (Fg) on tau pathology. The results showed that Fg deposits in the brains of tau P301S transgenic mice interact with tau, enhancing the cytotoxicity of pathological tau aggregates and promoting tau phosphorylation and aggregation. Notably, Fg-modified tau fibrils caused enhanced neuronal apoptosis and synaptic damage compared to unmodified fibrils. Furthermore, intrahippocampal injection of Fg-modified tau fibrils worsened the tau pathology, neuroinflammation, synaptic damage, neuronal apoptosis, and cognitive dysfunction in tau P301S mice compared to controls. The present study provides compelling evidence linking Fg and tau, thereby connecting cerebrovascular damage to tau pathology in AD. Consequently, inhibiting Fg-mediated tau pathology could potentially impede the progression of AD.
Animals ; tau Proteins/metabolism* ; Alzheimer Disease/metabolism* ; Fibrinogen/metabolism* ; Mice, Transgenic ; Mice ; Disease Models, Animal ; Memory Disorders/metabolism* ; Male ; Mice, Inbred C57BL ; Brain/metabolism* ; Hippocampus/metabolism* ; Protein Aggregation, Pathological/metabolism* ; Apoptosis ; Phosphorylation

ObjectiveTo investigate the effect and mechanism of Sishenwan in restoring the intestinal barrier function in the rat model of diarrhea-predominant irritable bowel syndrome （IBS-D） due to spleen-kidney Yang deficiency based on intestinal flora and short-chain fatty acids. MethodsAfter the delivery of 10 SPF-grade pregnant rats， 4 male suckling rats were kept in each litter for the experiment. The male suckling rats were randomly allocated into blank， model， low-dose （3.51 g·kg^-1） Sishenwan， high-dose （7.02 g·kg^-1） Sishenwan， and Peifeikang （0.54 g·kg^-1） groups， with 8 rats in each group. The blank group was fed conventionally， and the other groups were subjected to mother-child separation and Sennae Folium gavage （1 g·mL^-1， 10 mL·kg^-1） for the modeling of IBS-D due to spleen-kidney Yang deficiency. After the modeling was completed， the rats in Sishenwan groups were administrated with the corresponding dose of Sishenwan decoction by gavage， and the Peifeikang group with bifidobacterium triple live powder+normal saline suspension. The blank and model groups were treated with an equal volume of normal saline by gavage. The general conditions and fecal characteristics of rats were observed. After 2 weeks of administration， the rats were anesthetized for sample collection. The pathological changes of the colon tissue in rats were observed by hematoxylin-eosin staining. Enzyme-linked immunosorbent assay was employed to measure the levels of transforming growth factor-beta （TGF-β）， interleukin-10 （IL-10）， and interleukin-22 （IL-22）. Immumohistochemical staining （IHC） was performed to detect the positive expression of zonula occludens-1 （ZO-1） and occludin in the colon tissue. Western blot was employed to determine the protein levels of ZO-1 and occludin in the colon tissue of rats， and 16S rRNA gene sequencing was performed for intestinal flora. Gas chromatography-mass spectrometry was employed to determine the content of short-chain fatty acids （SCFAs） in the cecum contents of rats. ResultsThe colon tissue in the blank group presented a clear structure， neat glands， and no inflammatory cell infiltration. In the model group， the colon tissue showcased a disorganized structure， irregular arrangement of glands， and inflammatory cell infiltration. Compared with the model group， the low-dose and high-dose Sishenwan groups and the Peifeikang group exhibited an intact colon tissue structure， regular arrangement of glands， and reduced inflammatory cell infiltration. Compared with the blank group， the modeling lowered the levels of TGF-β， IL-10， and IL-22 in the serum （P<0.01）， down-regulated the protein levels of ZO-1 and occludin in the colon tissue （P<0.01）， and decreased the content of acetic acid and propionic acid and increased the content of butyric acid in cecum contents （P<0.05）. Compared with the model group， low-dose and high-dose Sishenwan raised the levels of TGF-β， IL-10， and IL-22 in the serum （P<0.05， P<0.01）， and Peifeikang elevated the levels of TGF-β and IL-10 in the serum （P<0.01）. High-dose Sishenwan and Peifeikang up-regulated the protein levels of ZO-1 and occludin （P<0.05， P<0.01）， increased the content of acetic acid and propionic acid in cecum contents （P<0.05）， and decreased the content of butyric acid （P<0.05）. The 16S rRNA gene sequencing results showed that the intestinal flora structure of the model group changed compared with that of the blank group. Compared with the model group， Sishenwan and Peifeikang increased the relative abundance of Lachnospiraceae， Muribaculaceae， Akkermansiaceae， Ligilactobacillus， UBA3282， Akkermansia， and Corynebacterium while reducing the relative abundance of Oscillospiraceae， Desulfovibrionaceae， Lactobacillus， Romboutsia， and Desulfovibrio. They can restore the intestinal flora structure similar to that in the blank group. ConclusionSishenwan can alleviate diarrhea symptoms and colonic mucosal inflammation， increase the expression of tight junction proteins in the colonic mucosa， and strengthen the intestinal barrier in IBS-D rats with the syndrome of spleen-kidney Yang deficiency. The mechanism of action may be related to optimizing the structure and balance of intestinal flora and regulating the SCFAs， and the effect of high-dose Sishenwan is obvious.

ObjectiveTo investigate the effect and mechanism of Sishenwan in restoring the intestinal barrier function in the rat model of diarrhea-predominant irritable bowel syndrome （IBS-D） due to spleen-kidney Yang deficiency based on intestinal flora and short-chain fatty acids. MethodsAfter the delivery of 10 SPF-grade pregnant rats， 4 male suckling rats were kept in each litter for the experiment. The male suckling rats were randomly allocated into blank， model， low-dose （3.51 g·kg^-1） Sishenwan， high-dose （7.02 g·kg^-1） Sishenwan， and Peifeikang （0.54 g·kg^-1） groups， with 8 rats in each group. The blank group was fed conventionally， and the other groups were subjected to mother-child separation and Sennae Folium gavage （1 g·mL^-1， 10 mL·kg^-1） for the modeling of IBS-D due to spleen-kidney Yang deficiency. After the modeling was completed， the rats in Sishenwan groups were administrated with the corresponding dose of Sishenwan decoction by gavage， and the Peifeikang group with bifidobacterium triple live powder+normal saline suspension. The blank and model groups were treated with an equal volume of normal saline by gavage. The general conditions and fecal characteristics of rats were observed. After 2 weeks of administration， the rats were anesthetized for sample collection. The pathological changes of the colon tissue in rats were observed by hematoxylin-eosin staining. Enzyme-linked immunosorbent assay was employed to measure the levels of transforming growth factor-beta （TGF-β）， interleukin-10 （IL-10）， and interleukin-22 （IL-22）. Immumohistochemical staining （IHC） was performed to detect the positive expression of zonula occludens-1 （ZO-1） and occludin in the colon tissue. Western blot was employed to determine the protein levels of ZO-1 and occludin in the colon tissue of rats， and 16S rRNA gene sequencing was performed for intestinal flora. Gas chromatography-mass spectrometry was employed to determine the content of short-chain fatty acids （SCFAs） in the cecum contents of rats. ResultsThe colon tissue in the blank group presented a clear structure， neat glands， and no inflammatory cell infiltration. In the model group， the colon tissue showcased a disorganized structure， irregular arrangement of glands， and inflammatory cell infiltration. Compared with the model group， the low-dose and high-dose Sishenwan groups and the Peifeikang group exhibited an intact colon tissue structure， regular arrangement of glands， and reduced inflammatory cell infiltration. Compared with the blank group， the modeling lowered the levels of TGF-β， IL-10， and IL-22 in the serum （P<0.01）， down-regulated the protein levels of ZO-1 and occludin in the colon tissue （P<0.01）， and decreased the content of acetic acid and propionic acid and increased the content of butyric acid in cecum contents （P<0.05）. Compared with the model group， low-dose and high-dose Sishenwan raised the levels of TGF-β， IL-10， and IL-22 in the serum （P<0.05， P<0.01）， and Peifeikang elevated the levels of TGF-β and IL-10 in the serum （P<0.01）. High-dose Sishenwan and Peifeikang up-regulated the protein levels of ZO-1 and occludin （P<0.05， P<0.01）， increased the content of acetic acid and propionic acid in cecum contents （P<0.05）， and decreased the content of butyric acid （P<0.05）. The 16S rRNA gene sequencing results showed that the intestinal flora structure of the model group changed compared with that of the blank group. Compared with the model group， Sishenwan and Peifeikang increased the relative abundance of Lachnospiraceae， Muribaculaceae， Akkermansiaceae， Ligilactobacillus， UBA3282， Akkermansia， and Corynebacterium while reducing the relative abundance of Oscillospiraceae， Desulfovibrionaceae， Lactobacillus， Romboutsia， and Desulfovibrio. They can restore the intestinal flora structure similar to that in the blank group. ConclusionSishenwan can alleviate diarrhea symptoms and colonic mucosal inflammation， increase the expression of tight junction proteins in the colonic mucosa， and strengthen the intestinal barrier in IBS-D rats with the syndrome of spleen-kidney Yang deficiency. The mechanism of action may be related to optimizing the structure and balance of intestinal flora and regulating the SCFAs， and the effect of high-dose Sishenwan is obvious.