Melatonin (Mel) has been shown to have cardioprotective effects, but its action on ion channels is unclear. In this experiment, we investigated the inhibitory effect of Mel on late sodium currents (I_Na.L) in mouse ventricular myocytes and the anti-arrhythmic effect at the organ level as well as its mechanism. The whole-cell patch clamp technique was applied to record the ionic currents and action potential (AP) in mouse ventricular myocytes while the electrocardiogram (ECG) and monophasic action potential (MAP) were recorded simultaneously in mouse hearts using a multichannel acquisition and analysis system. The results demonstrated that the half maximal inhibitory concentration (IC₅₀) values of Mel on transient sodium current (I_Na.T) and specific I_Na.L opener 2 nmol·L^-1 sea anemone toxins II (ATX II) increased I_Na.L were 686.615 and 7.37 μmol·L^-1, respectively. Mel did not affect L-type calcium current (I_Ca.L), transient outward current (I_to), and AP. In addition, 16 μmol·L^-1 Mel shortened ATX II-prolonged action potential duration (APD), suppressed ATX II-induced early afterdepolarizations (EADs), and significantly reduced the incidence of ventricular tachycardia (VT) and ventricular fibrillation (VF) in Langendorff-perfused mouse hearts. In conclusion, Mel exerted its antiarrhythmic effects principally by blocking I_Na.L, thus providing a significant theoretical basis for new clinical applications of Mel. Animal welfare and experimental process are in accordance with the regulations of the Experimental Animal Ethics Committee of Wuhan University of Science and Technology (2023130).

Most patients with differentiated thyroid cancer have a good prognosis after radioiodine-131 therapy,but a small number of patients are insensitive to radioiodine-131 therapy and even continue to develop disease.At present,some targeted drugs can improve progression-free survival in patients with radioactive iodine-refractory differentiated thyroid cancer(RAIR-DTC),such as sorafenib and levatinib,have been approved for the treatment of RAIR-DTC.However,due to the presence of primary and acquired drug resistance,drug efficacy in these patients is unsatisfactory.This review introduces the acquired drug resistance mechanism of sorafenib in the regulation of mitogen-activated protein kinase(MAPK)and phosphatidylinositol-3-kinase(PI3K)pathways and proposes related treatment strategies,in order to provide a reference for similar drug resistance mechanism of sorafenib and effective treatment of RAIR-DTC.

Objective To investigate the predictive value of new simplified insulin resistance(IR)assessment indexes in identifying subclinical left ventricular systolic function impairment in patients with type 2 diabetes mellitus(T2DM).Methods A total of 150 T2DM patients with preserved left ventricular ejection fraction(LVEF≥50%)who were admitted to Department of Endocrinology of the First Affiliated Hospital of Air Force Medical University from June 2021 to December 2021 were retrospectively analyzed.All patients underwent two-dimensional speckle tracking echocardiography to measure left ventricular global longitudinal strain(GLS).According to GLS value,the subjects were divided into the normal group(GLS≥18%group,n=80)and the impaired group(GLS<18%group,n=70).Some new simplified IR assessment indicators were calculated and compared between the two groups,including body mass index(BMI),TG/HDL-C ratio,triglyceride-glucose(TyG)index,TyG-BMI index,TyG-WHR and metabolic score for IR(METS-IR).Correlation between the GLS and the new simplified IR assessment indexes was analyzed.The receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of different simplified IR assessment indexes,with the area under the curve(AUC)calculated.Furthermore,according to whether the subjects were complicated with hypertension,binary logistics regression analysis was performed to explore the independent correlation between the simplified IR assessment index and GLS<18%.Results Total 150 were included with aged(54.5±13.7)years with 96(64.0%)men and 54(36.0%)women.Compared with the GLS≥18%group,the TG/HDL-C ratio,TyG index,TyG-BMI,and METS-IR of subjects in the GLS<18%group were significantly increased(P<0.05).Pearson correlation analysis showed that TG/HDL-C ratio,TyG index,TyG-BMI,TyG-WHR,and METS-IR were negatively correlated with GLS(P<0.05).ROC analysis showed that TyG index had a certain predictive value for the evaluation of GLS<18%(AUC=0.678,95%CI 0.591-0.765,P<0.001).Stratification based on hypertension and further adjusting for confounding factors,TyG index remains significantly associated with GLS<18%(OR=3.249,95%CI 1.045-10.103,P=0.042).Conclusions The novel simplified insulin resistance evaluation indexes are closely associated with left ventricular subclinical systolic dysfunction in T2DM patients with preserved ejection fraction.TyG index is an effective index to identify left ventricular subclinical dysfunction in these populations.

Tuberous sclerosis complex(TSC)is a rare genetic disease that can lead to benign dysplasia in multiple organs such as the skin, brain, eyes, oral cavity, heart, lungs, kidneys, liver, and bones. Its main symptoms include epilepsy, intellectual disabilities, skin depigmentation, and facial angiofibromas, whilst incidence is approximately 1 in 10 000 to 1 in 6000 newborns. This case presents a middle-aged woman who initially manifested with epilepsy and nodular depigmentation. Later, she developed a lower abdominal mass, elevated creatinine, and severe anemia. Based on clinical features and whole exome sequencing, the primary diagnosis was confirmed as TSC. Laboratory and imaging examinations revealed that the lower abdominal mass originated from the uterus. CT-guided biopsy pathology and surgical pathology suggested a combination of leiomyoma and abscess. With the involvement of multiple organs and various complications beyond the main diagnosis, the diagnostic and therapeutic process for this patient highlights the importance of rigorous clinical thinking and multidisciplinary collaboration in the diagnosis and treatment of rare and challenging diseases.

The pathogenesis of osteoarthritis (OA) is related to a variety of factors such as mechanical overload, metabolic dysfunction, aging, etc., and is a group of total joint diseases characterized by intra-articular chondrocyte apoptosis, cartilage fibrillations, synovial inflammation, and osteophyte formation. At present, the treatment methods for osteoarthritis include glucosamine, non-steroidal anti-inflammatory drugs, intra-articular injection of sodium hyaluronate, etc., which are difficult to take effect in a short period of time and require long-term treatment, so the patients struggle to adhere to doctor’s advice. Some methods can only provide temporary relief without chondrocyte protection, and some even increase the risk of cardiovascular disease and gastrointestinal disease. In the advanced stages of OA, patients often have to undergo joint replacement surgery due to pain and joint dysfunction. Mitochondrial dysfunction plays an important role in the development of OA. It is possible to improve mitochondrial biogenesis, quality control, autophagy balance, and oxidative stress levels, thereby exerting a protective effect on chondrocytes in OA. Therefore, compared to traditional treatments, improving mitochondrial function may be a potential treatment for OA. Here, we collected relevant literature on mitochondrial research in OA in recent years, summarized the potential pathogenic factors that affect the development of OA through mitochondrial pathways, and elaborated on relevant treatment methods, in order to provide new diagnostic and therapeutic ideas for the research field of osteoarthritis.

Objective To investigate the effects of exercise and complex environment on lipopolysaccharide(LPS)-induced dopaminergic neuron death in the substantia nigra of midbrain.Methods C57BL/6 mice were divided into control group,LPS group,LPS+swimming group and LPS+complex environment group,with 7 mice in each group.The mice in the LPS group were injected with LPS into the brain to establish an inflammatory model of Parkinson's disease and lived in cages for 2 weeks.Mice in LPS+swimming group were forced to swim for 15 minutes every day for 2 weeks after modeling.The mice in the LPS+complex environment group were placed in a complex environment for 2 weeks after modeling.The control group mice were not treated.After 14 days of modeling,behavioral experiments such as footprint,open field and rotating rod were performed on each group of mice to detect the autonomous exercise ability,exercise balance ability and depression level of mice.The expressions of tyrosine hydroxylase(TH)in substantia nigra was detected by immunohistochemical staining and Western blotting.The expressions of brain-derived neurotrophic factor(BDNF),Caspase-3,interleukin-1β(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in the substantia nigra of the midbrain were detected by Western blotting.The transcription levels of IL-1β,IL-6 and TNF-α in substantia nigra were detected by RT-PCR.Results Compared with the control group,the exercise ability and balance ability of mice in LPS group,LPS+swimming group and LPS+complex environment group decreased,the depression level increased(P＜0.001),the number of TH positive neurons and BDNF protein decreased significantly(P＜0.001),and the contents of Caspase-3,IL-1β,IL-6 and TNF-α increased significantly(P＜0.001).Compared with the LPS group,the exercise ability and balance ability of the mice in the LPS+swimming group and the LPS+complex environment group were restored,the depression level decreased significantly(P＜0.01),the survival number of TH positive neurons and the content of BDNF increased significantly(P＜0.01),Caspase-3,IL-1β,IL-6 and TNF-α reduced significantly(P＜0.01),and the phenomenon in the LPS+complex environment group was more significant.Conclusion Exercise and complex environment can inhibit LPS-induced central nervous system inflammation in mice,thereby reducing damage to midbrain substantia nigra neurons,and the inhibitory effect of LPS+complex environment group is more significant.

Further evidence is needed to explore the impact of high-altitude environments on the neurologic function of neonates.Non-invasive techniques such as cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography can provide data on cerebral oxygenation and brain electrical activity.This study will conduct multiple cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography monitoring sessions at various time points within the first 3 days postpartum for healthy full-term neonates at different altitudes.The obtained data on cerebral oxygenation and brain electrical activity will be compared between different altitudes,and corresponding reference ranges will be established.The study involves 6 participating centers in the Chinese High Altitude Neonatal Medicine Alliance,with altitude gradients divided into 4 categories:800 m,1 900 m,2 400 m,and 3 500 m,with an anticipated sample size of 170 neonates per altitude gradient.This multicenter prospective cohort study aims to provide evidence supporting the impact of high-altitude environments on early brain function and metabolism in neonates.[Chinese Journal of Contemporary Pediatrics,2024,26(4):403-409]

Objective:To investigate the clinical significance of bone metabolic indexes for disease assessment and curative effect monitoring in multiple myeloma(MM)bone disease(MBD)patients with different blood separation results.Methods:A total of 134 newly diagnosed MM patients treated in Cangzhou Hospital of Integrated TCM-WM-Hebei were enrolled and divided into control group[119 cases,serum,colloid and red blood cell(RBC)from top to bottom of sample]and abnormal group(15 cases,serum,mixed layer of RBC and serum,colloid and RBC from top to bottom of sample)according to the results of blood separation.According to the imaging findings,MBD was classified into grade 0-4,grade 0-2 was mild,and grade 3-4 was severe.The MBD grade of patients in the two groups was analyzed.The curative effect of MBD patients after chemotherapy and the changes of blood separation results and bone metabolic indexes before and after treatment were evaluated.The correlation between β 2-microglobulin(MG)and bone metabolic indexes was analyzed by Pearson correlation analysis.Results:In the control group,there were 69 cases of grade 0-2 and 50 cases of grade 3-4,while in the abnormal group,there were 5 cases of grade 0-2 and 10 cases of grade 3-4,the difference was statistically significant(P＜0.05).The serum β 2-MG,β-CTX levels in abnormal group were both significantly higher than those in control group,while the levels of P1NP and osteocalcin(OC)were significantly lower(all P＜0.001).In the control group,there were 95 patients with ≥ partial response(PR)and the blood separation results were not changed,while 24 patients with＜PR and 5 of them had abnormal blood separation results.In the abnormal group,9 patients with efficacy≥PR showed normal blood separation results,while 6 patients with efficacy＜PR and 5 of them still remained abnormal blood separation results.Compared with before treatment,β-CTX and β 2-MG of patients with efficacy ≥ PR were significantly decreased but P1NP and OC increased in the control group(all P＜0.00 1),which was the same as abnoraml group(both P＜0.001,P＜0.01).There were no significant changes in the levels of all indexes in the two groups of patients with efficacy＜PR(P＞0.05).Compared with before treatment,the levels of β-CTX and β 2-MG in the control group with unchanged blood separation results were significantly decreased(both P＜0.00l),while the levels of P1NP and OC were significantly increased(P＜0.01,P＜0.001),and the level of each index in the patients transformed to abnormal blood separation result after treatment did not significantly change(P＞0.05);the levels of β-CTX and β 2-MG in the abnormal group transformed to normal blood separation result were significantly decreased(both P＜0.01),while the levels of P1NP and OC were significantly increased(P＜0.001,P＜0.01),and the level of each index in patients with unchanged blood separation results did not significantly change(P＞0.05).Pearson correlation analysis showed that serumβ 2-MG was positively correlated with β-CTX(r=0.709,P＜0.001),and negatively correlated with P1NP and OC(r=-0.410,r=-0.412,both P＜0.001).Conclusion:MBD patients with abnormal blood separation results have higher bone disease grade and poor prognosis,which is closely related to the significant increase of bone resorption index β-CTX level and decrease of bone formation index P1NP and OC levels,leading to more serious bone metabolic homeostasis disorder.The results of blood separation combined with the changes of bone metabolic indexes can be used as one of the comprehensive predictors of disease condition,efficacy monitoring and prognosis evaluation of MBD patients.

Objective:To screen interleukin(IL)-1β secretion-related membrane transporters by macrophage experiment in vitro and conventional knockout mice.Methods:THP-1 cell line was differentiated to obtain human THP-1-derived macrophages,and the primary macrophages were obtained from human peripheral blood.FVB wild-type mice with the same sex and age were used as the controls of MRP1 knockout mice.The macrophages in abdominal cavity and bone marrow of mice were cultivated.The cells were treated with ABCC1/MRP1,ABCG2/BCRP,ABCB1/P-gp,OATP1B1,and MATE transporter inhibitors,then stimulated by lipopolysaccharide and adenosine triphosphate.The secretion level of IL-iβ was detected by ELISA,Western blot,and immunofluorescence.Results:After inhibiting ABCC1/MRP1 transporter,the secretion of IL-1β decreased significantly,while inhibition of the other 4 transporters had no effect.In animal experiment,the level of IL-1 β secreted by macrophages in bone marrow of MRP1 knockout mice was significantly lower than control group(P＜0.05).Conclusion:ABCC1/MRP1 transporter is a newly discovered IL-1β secretion pathway,which is expected to become a new target for solving clinical problems such as cytokine release syndrome.

Dihydroflavonol 4-reductase (DFR) plays an essential role in the biosynthesis of anthocyanin and regulation of plant flower color. Based on the transcriptome data of Cistanche tubulosa (Schenk) Wight, a full-length cDNA sequence of CtDFR gene was cloned by reverse transcription-polymerase chain reaction (RT-PCR). CtDFR contains an open reading frame (ORF) of 1 263 bp which encodes 420 amino acids with a predicted molecular weight of 47.5 kDa. The sequence analysis showed that CtDFR contains a nicotinamide adenine dinucleotide phosphate (NADPH) binding domain and a specific substrate binding domain. The expression analysis indicated that CtDFR was highly expressed in red and purple flowers, and the relative expression levels were 4.04 and 19.37 times higher than those of white flowers, respectively. The recombinant CtDFR protein was expressed in E.coli BL21 (DE3) using vector pET-28a-CtDFR and was purified. In vitro enzyme activity analysis, CtDFR could reduce three types of dihydroflavonols including dihydrokaempferol, dihydroquercetin, and dihydromyricetin to leucopelargonidin, leucocyanidin and leucodelphinidin. Subcellular localization analysis showed that CtDFR was mainly localized in the cytoplasm. These results demonstrate that CtDFR plays an important role in regulation of flower color in C. tubulosa and make a valuable contribution for the further investigation on the regulation mechanism of C. tubulosa (Schenk) Wight flower color.