Circadian rhythm is an endogenous biological clock mechanism that enables organisms to adapt to the earth’s alternation of day and night. It plays a fundamental role in regulating physiological functions and behavioral patterns, such as sleep, feeding, hormone levels and body temperature. By aligning these processes with environmental changes, circadian rhythm plays a pivotal role in maintaining homeostasis and promoting optimal health. However, modern lifestyles, characterized by irregular work schedules and pervasive exposure to artificial light, have disrupted these rhythms for many individuals. Such disruptions have been linked to a variety of health problems, including sleep disorders, metabolic syndromes, cardiovascular diseases, and immune dysfunction, underscoring the critical role of circadian rhythm in human health. Among the numerous systems influenced by circadian rhythm, the skin—a multifunctional organ and the largest by surface area—is particularly noteworthy. As the body’s first line of defense against environmental insults such as UV radiation, pollutants, and pathogens, the skin is highly affected by changes in circadian rhythm. Circadian rhythm regulates multiple skin-related processes, including cyclic changes in cell proliferation, differentiation, and apoptosis, as well as DNA repair mechanisms and antioxidant defenses. For instance, studies have shown that keratinocyte proliferation peaks during the night, coinciding with reduced environmental stress, while DNA repair mechanisms are most active during the day to counteract UV-induced damage. This temporal coordination highlights the critical role of circadian rhythms in preserving skin integrity and function. Beyond maintaining homeostasis, circadian rhythm is also pivotal in the skin’s repair and regeneration processes following injury. Skin regeneration is a complex, multi-stage process involving hemostasis, inflammation, proliferation, and remodeling, all of which are influenced by circadian regulation. Key cellular activities, such as fibroblast migration, keratinocyte activation, and extracellular matrix remodeling, are modulated by the circadian clock, ensuring that repair processes occur with optimal efficiency. Additionally, circadian rhythm regulates the secretion of cytokines and growth factors, which are critical for coordinating cellular communication and orchestrating tissue regeneration. Disruptions to these rhythms can impair the repair process, leading to delayed wound healing, increased scarring, or chronic inflammatory conditions. The aim of this review is to synthesize recent information on the interactions between circadian rhythms and skin physiology, with a particular focus on skin tissue repair and regeneration. Molecular mechanisms of circadian regulation in skin cells, including the role of core clock genes such as Clock, Bmal1, Per and Cry. These genes control the expression of downstream effectors involved in cell cycle regulation, DNA repair, oxidative stress response and inflammatory pathways. By understanding how these mechanisms operate in healthy and diseased states, we can discover new insights into the temporal dynamics of skin regeneration. In addition, by exploring the therapeutic potential of circadian biology in enhancing skin repair and regeneration, strategies such as topical medications that can be applied in a time-limited manner, phototherapy that is synchronized with circadian rhythms, and pharmacological modulation of clock genes are expected to optimize clinical outcomes. Interventions based on the skin’s natural rhythms can provide a personalized and efficient approach to promote skin regeneration and recovery. This review not only introduces the important role of circadian rhythms in skin biology, but also provides a new idea for future innovative therapies and regenerative medicine based on circadian rhythms.

Objective: To explore the relationship of physical exercise behavior with mobile phone addiction and mental health of college students, so as to provide evidence for interventions to improve mobile phone addiction and mental health of college students. Methods: From October 8 to December 20 in 2024, 896 college students from 4 colleges in Beijing were selected using a combination of convenience sampling and stratified random cluster sampling method. Physical Activity Rating Scale (PARS-3), Mobile Phone Addiction Tendency Scale (MPATS), Adolescence Mental Health Diathesis Questionnaire (AMHDQ) and Symptom Checklist 90 (SCL-90) were used. The correlation of mobile phone addiction and mental health on physical exercise behavior of college students were analyzed by multivariable Logistic regression and linear regression. Results: Among the surveyed college students, 504 (56.25%) students had low exercise, 262 (29.24%) had moderate exercise, 130 (14.51%) had high exercise, and 392 (43.75%) had sufficient exercise. The total score of PARS-3 was 18.00 ( 15.00 , 33.00) points. Logistic regression analysis showed that the total score of MPATS ( OR=1.022, 95%CI =1.008-1.036), the total score of SCL-90 ( OR=1.010, 95%CI = 1.005 -1.015), the total AMHDQ score ( OR=0.995, 95%CI =0.992-0.998) were significantly associated with insufficient exercise among college students ( P <0.05). Linear regression analysis showed that the scores of MPATS, AMHDQS and SCL-90 were significantly correlated with physical exercise behavior ( B=-0.20, 0.04, -0.07, P <0.05). Conclusion The physical exercise behavior of college students is related to mobile phone addiction and mental health.

Background: Older adults undergoing surgery frequently have multiple comorbidities and reduced physical and cognitive reserves. This study aims to assess the effect of physical and cognitive frailty on long-term mortality in older patients undergoing elective non-cardiac surgery in a tertiary center. Methods: Patients aged ≥65 years old admitted to surgical wards at the University of Malaya Medical Centre were recruited. Physical frailty and cognitive status were assessed using the Fried Frailty Index (FFI) and the Montreal Cognitive Assessment, respectively. Patients were stratified into six groups based on their frailty and cognitive status: Group 1, normal cognition and non-frail (reference group); Group 2, normal cognition and frail; Group 3, mild cognitive impairment (MCI) and non-frail; Group 4, MCI and frail; Group 5, dementia and non-frail; and Group 6, dementia and frail. Results: A total of 406 patients with a mean FFI score of 1.1±1.2 were recruited. Predictors of mortality include male sex (hazard ratio [HR]=1.96; 95% confidence interval [CI], 1.14–3.37; p=0.015), presence of active malignancy (HR=3.86; 95% CI, 2.14–6.95; p<0.001), and high FFI scores (1.8±1.2 vs. 1.0±1.1; p=0.013). Compared to Group 1, long-term mortality risk was significantly increased in Group 4 (HR=3.17; 95% CI, 1.36–7.38) and Group 6 (HR=3.91; 95% CI, 1.62–9.43) patients. Conclusion The combination of physical frailty and cognitive impairment was associated with long-term mortality risk among older patients who underwent elective non-cardiac surgery. This highlights the importance of assessing physical frailty and cognitive function of all older surgical patients to guide targeted intervention, especially for those with impairments which may be potentially reversible.

Background: Older adults undergoing surgery frequently have multiple comorbidities and reduced physical and cognitive reserves. This study aims to assess the effect of physical and cognitive frailty on long-term mortality in older patients undergoing elective non-cardiac surgery in a tertiary center. Methods: Patients aged ≥65 years old admitted to surgical wards at the University of Malaya Medical Centre were recruited. Physical frailty and cognitive status were assessed using the Fried Frailty Index (FFI) and the Montreal Cognitive Assessment, respectively. Patients were stratified into six groups based on their frailty and cognitive status: Group 1, normal cognition and non-frail (reference group); Group 2, normal cognition and frail; Group 3, mild cognitive impairment (MCI) and non-frail; Group 4, MCI and frail; Group 5, dementia and non-frail; and Group 6, dementia and frail. Results: A total of 406 patients with a mean FFI score of 1.1±1.2 were recruited. Predictors of mortality include male sex (hazard ratio [HR]=1.96; 95% confidence interval [CI], 1.14–3.37; p=0.015), presence of active malignancy (HR=3.86; 95% CI, 2.14–6.95; p<0.001), and high FFI scores (1.8±1.2 vs. 1.0±1.1; p=0.013). Compared to Group 1, long-term mortality risk was significantly increased in Group 4 (HR=3.17; 95% CI, 1.36–7.38) and Group 6 (HR=3.91; 95% CI, 1.62–9.43) patients. Conclusion The combination of physical frailty and cognitive impairment was associated with long-term mortality risk among older patients who underwent elective non-cardiac surgery. This highlights the importance of assessing physical frailty and cognitive function of all older surgical patients to guide targeted intervention, especially for those with impairments which may be potentially reversible.

Objective To explore the polymorphism of tyrosinase (TYR) and melanocortin 1 receptor (MC1R) genes and their mRNA expression levels in relation to coat-color phenotypes in guinea pigs, providing genetic markers for locating dominant traits in guinea pigs. Methods A total of 57 self-bred ordinary-level guinea pigs were selected and divided into three groups based on coat color: white (n=22), variegated (n=22) and black (n=13). The guinea pigs were euthanized with an overdose of pentobarbital sodium via intraperitoneal injection. DNA was then extracted from the dorsal skin tissue. Polymorphism in the coding sequence (CDS) of the exons of the TYR and MC1R genes in each group was detected by cloning and sequencing. The mRNA expression of the two genes in skin tissues was detected by real-time fluorescent quantitative PCR to investigate the relationship between these genes and guinea pig coat color. Results A single nucleotide polymorphism (SNP) site was found in the CDS region of TYR exon Ⅰ, where the base A was replaced by G. All white guinea pigs had the G/G genotype for TYR, while no deep-colored (variegated and black) guinea pigs exhibited the G/G genotype for TYR. Most deep-colored guinea pigs had the A/A genotype, and a few had A/G genotype. The A/A genotype frequency in black guinea pigs was higher than in variegated guinea pigs. A 2 760 bp sequence deletion was identified in the exon of the MC1R gene, marked as the - gene, with non-deleted samples marked as N gene. Most white guinea pigs had the -/- genotype for MC1R, variegated guinea pigs mainly had the -/N genotype, and black guinea pigs mainly had the N/N genotype, with a few showing the -/N. The TYR gene expression level was higher in white guinea pigs, lower in variegated guinea pigs, and intermediate in black guinea pigs, but there was no significant difference among the three groups (P>0.05). The MC1R gene expression level in white guinea pigs was extremely low, while both variegated and black guinea pigs showed significantly higher levels than white guinea pigs (P<0.01). Black guinea pigs showed significantly higher levels than variegated guinea pigs (P<0.05). ConclusionThe TYR and MC1R genes synergistically regulate coat color of guinea pigs. The G-site mutation in the TYR gene may lead to albinism, and the change of N-site in the MC1R gene affects the depth of the coat color.

ObjectiveTo investigate the analgesic effect of Tuina at the "Weizhong （BL 40）" on neuropathic pain in a rat model of chronic constriction injury （CCI） of the sciatic nerve and its potential central spinal mechanisms. MethodsThirty-two Sprague-Dawley rats were randomly divided into four groups （8 rats in each group）， sham-operated group， model group， Tuina group， and blockade group. The CCI model was established in the model group， Tuina group， and the blockade group by ligating the sciatic nerve with catgut， while the sham-operated group underwent only sciatic nerve exposure without ligation. From postoperative day 4 to day 14， rats in the Tuina group and the blockade group received Tuina manipulation at the "Weizhong （BL 40）" using a dynamic pressure distribution measurement system （5 N pressure， 2 Hz frequency， 10 min per session， once daily）. The blockade group also received intraperitoneal injections of the microglial inhibitor minocycline （10 mg/kg） once daily. The sham-operated and the model group underwent the same handling and fixation as the Tuina group without actual Tuina. Mechanical withdrawal threshold （MWT） and paw withdrawal latency （PWL） were measured before surgery and on day 3， 7， 10， and 14 post-surgery. Transmission electron microscopy was used to evaluate sciatic nerve injury and repair， measuring axon diameter and total myelinated fiber diameter to calculate the g-ratio. Western Blotting was performed to detect the protein levels of ionized calcium-binding adapter molecule 1 （Iba-1）， CD206， CD68， interleukin-10 （IL-10）， and β-endorphin （β-EP） precursor pro-opiomelanocortin （POMC） in the ipsilateral spinal dorsal horn. ResultsCompared with the sham-operated group， the model group showed significantly reduced MWT and PWL on day 3， 7， 10， and 14 （P＜0.01）. Compared with the model group， the Tuina group and the blockade group showed increased MWT and PWL on day 10 and 14 （P＜0.05）. Compared with the Tuina group， the blockade group exhibited higher MWT on day 7， 10， and 14， and higher PWL on day 10 （P＜0.05）. Sciatic nerve pathological morphology revealed intact and well-structured myelin in the sham-operated group， while the model group exhibited myelin collapse， distortion， and myelin ovoid formation. The Tuina group displayed partially irregular myelin with occasional myelin collapse， whereas the blockade group exhibited partial myelin irregularities and phospholipid shedding. Compared with the sham-operated group， the model group showed a decreased g-ratio and increased levels of Iba-1 and CD68 in the spinal dorsal horn （P＜0.05 or P＜0.01）. Compared with the model group， the Tuina group and the blockade group exhibited an increased g-ratio and reduced Iba-1 and CD68 levels. Additionally， the Tuina group showed elevated levels of CD206， IL-10， and POMC， whereas the blockade group had decreased CD206 levels （P＜0.05）. ConclusionTuina at "Weizhong （BL 40）" alleviates neuropathic pain in CCI rats， potentially by regulating microglial activation in the spinal cord， inhibiting M1 polarization while promoting M2 polarization， and activating the IL-10/β-EP pathway to exert analgesic effects.

Background: Older adults undergoing surgery frequently have multiple comorbidities and reduced physical and cognitive reserves. This study aims to assess the effect of physical and cognitive frailty on long-term mortality in older patients undergoing elective non-cardiac surgery in a tertiary center. Methods: Patients aged ≥65 years old admitted to surgical wards at the University of Malaya Medical Centre were recruited. Physical frailty and cognitive status were assessed using the Fried Frailty Index (FFI) and the Montreal Cognitive Assessment, respectively. Patients were stratified into six groups based on their frailty and cognitive status: Group 1, normal cognition and non-frail (reference group); Group 2, normal cognition and frail; Group 3, mild cognitive impairment (MCI) and non-frail; Group 4, MCI and frail; Group 5, dementia and non-frail; and Group 6, dementia and frail. Results: A total of 406 patients with a mean FFI score of 1.1±1.2 were recruited. Predictors of mortality include male sex (hazard ratio [HR]=1.96; 95% confidence interval [CI], 1.14–3.37; p=0.015), presence of active malignancy (HR=3.86; 95% CI, 2.14–6.95; p<0.001), and high FFI scores (1.8±1.2 vs. 1.0±1.1; p=0.013). Compared to Group 1, long-term mortality risk was significantly increased in Group 4 (HR=3.17; 95% CI, 1.36–7.38) and Group 6 (HR=3.91; 95% CI, 1.62–9.43) patients. Conclusion The combination of physical frailty and cognitive impairment was associated with long-term mortality risk among older patients who underwent elective non-cardiac surgery. This highlights the importance of assessing physical frailty and cognitive function of all older surgical patients to guide targeted intervention, especially for those with impairments which may be potentially reversible.

PURPOSE: To investigate the incidence and influencing factors of bone loss in patients with spinal cord injury (SCI). METHODS: A retrospective case-control study was conducted. Patients with SCI in our hospital from January 2019 to March 2023 were collected. According to the correlation between bone mineral density (BMD) at different sites, the patients were divided into the lumbar spine group and the hip joint group. According to the BMD value, the patients were divided into the normal bone mass group (t > -1.0 standard deviation) and the osteopenia group (t ≤ -1.0 standard deviation). The influencing factors accumulated as follows: gender, age, height, weight, cause of injury, injury segment, injury degree, time after injury, start time of rehabilitation, motor score, sensory score, spasticity, serum value of alkaline phosphatase, calcium, and phosphorus. The trend chart was drawn and the influencing factors were analyzed. SPSS 26.0 was used for statistical analysis. Correlation analysis was used to test the correlation between the BMD values of the lumbar spine and bilateral hips. Binary logistic regression analysis was used to explore the influencing factors of osteoporosis after SCI. p < 0.05 was considered statistically significant. RESULTS: The incidence of bone loss in patients with SCI was 66.3%. There was a low concordance between bone loss in the lumbar spine and the hip, and the hip was particularly susceptible to bone loss after SCI, with an upward trend in incidence (36% - 82%). In this study, patients with SCI were divided into the lumbar spine group (n = 100) and the hip group (n = 185) according to the BMD values of different sites. Then, the lumbar spine group was divided into the normal bone mass group (n = 53) and the osteopenia group (n = 47); the hip joint group was divided into the normal bone mass group (n = 83) and the osteopenia group (n = 102). Of these, lumbar bone loss after SCI is correlated with gender and weight (p = 0.032 and < 0.001, respectively), and hip bone loss is correlated with gender, height, weight, and time since injury (p < 0.001, p = 0.015, 0.009, and 0.012, respectively). CONCLUSIONS The incidence of bone loss after SCI was high, especially in the hip. The incidence and influencing factors of bone loss in the lumbar spine and hip were different. Patients with SCI who are male, low height, lightweight, and long time after injury were more likely to have bone loss.
Humans ; Spinal Cord Injuries/complications* ; Male ; Female ; Retrospective Studies ; Incidence ; Adult ; Bone Density ; Middle Aged ; Case-Control Studies ; Osteoporosis/etiology* ; Lumbar Vertebrae ; Bone Diseases, Metabolic/etiology* ; Aged ; Risk Factors

Testicular descent occurs in two consecutive stages: the transabdominal stage and the inguinoscrotal stage. Androgens play a crucial role in the second stage by influencing the development of the gubernaculum, a structure that pulls the testis into the scrotum. However, the mechanisms of androgen actions underlying many of the processes associated with gubernaculum development have not been fully elucidated. To identify the androgen-regulated genes, we conducted large-scale gene expression analyses on the gubernaculum harvested from luteinizing hormone/choriogonadotropin receptor knockout ( Lhcgr KO) mice, an animal model of inguinoscrotal testis maldescent resulting from androgen deficiency. We found that the expression of secreted protein acidic and rich in cysteine (SPARC)-related modular calcium binding 1 ( Smoc1 ) was the most severely suppressed at both the transcript and protein levels, while its expression was the most dramatically induced by testosterone administration in the gubernacula of Lhcgr KO mice. The upregulation of Smoc1 expression by testosterone was curtailed by the addition of an androgen receptor antagonist, flutamide. In addition, in vitro studies demonstrated that SMOC1 modestly but significantly promoted the proliferation of gubernacular cells. In the cultures of myogenic differentiation medium, both testosterone and SMOC1 enhanced the expression of myogenic regulatory factors such as paired box 7 ( Pax7 ) and myogenic factor 5 ( Myf5 ). After short-interfering RNA-mediated knocking down of Smoc1 , the expression of Pax7 and Myf5 diminished, and testosterone alone did not recover, but additional SMOC1 did. These observations indicate that SMOC1 is pivotal in mediating androgen action to regulate gubernaculum development during inguinoscrotal testicular descent.
Animals ; Male ; Mice ; Testis/growth & development* ; Mice, Knockout ; Androgens/pharmacology* ; Testosterone/pharmacology* ; Receptors, LH/metabolism* ; Calcium-Binding Proteins/metabolism*

OBJECTIVES: To investigate the clinical sub-phenotype (SP) of pediatric acute kidney injury (AKI) and their association with clinical outcomes. METHODS: General status and initial values of laboratory markers within 24 hours after admission to the pediatric intensive care unit (PICU) were recorded for children with AKI in the derivation cohort (n=650) and the validation cohort (n=177). In the derivation cohort, a least absolute shrinkage and selection operator (LASSO) regression analysis was used to identify death-related indicators, and a two-step cluster analysis was employed to obtain the clinical SP of AKI. A logistic regression analysis was used to develop a parsimonious classifier model with simplified metrics, and the area under the curve (AUC) was used to assess the value of this model. This model was then applied to the validation cohort and the combined derivation and validation cohort. The association between SPs and clinical outcomes was analyzed with all children with AKI as subjects. RESULTS: In the derivation cohort, two clinical SPs of AKI (SP1 and SP2) were identified by the two-step cluster analysis using the 20 variables screened by LASSO regression, namely SP_d1 group (n=536) and SP_d2 group (n=114). The simplified classifier model containing eight variables (P<0.05) had an AUC of 0.965 in identifying the two clinical SPs of AKI (P<0.001). The validation cohort was clustered into SP_v1 group (n=156) and SP_v2 group (n=21), and the combined derivation and validation cohort was clustered into SP1 group (n=694) and SP2 group (n=133). After adjustment for confounding factors, compared with the SP1 group, the SP2 group had significantly higher incidence rates of multiple organ dysfunction syndrome and death during the PICU stay (P<0.001), and SP2 was significantly associated with the risk of death within 28 days after admission to the PICU (P<0.001). CONCLUSIONS This study establishes a parsimonious classifier model and identifies two clinical SPs of AKI with different clinical features and outcomes.The SP2 group has more severe disease and worse clinical prognosis.
Humans ; Acute Kidney Injury/diagnosis* ; Prognosis ; Male ; Female ; Child ; Child, Preschool ; Phenotype ; Infant ; Logistic Models ; Adolescent