1.The Role of AMPK in Diabetic Cardiomyopathy and Related Intervention Strategies
Fang-Lian LIAO ; Xiao-Feng CHEN ; Han-Yi XIANG ; Zhi XIA ; Hua-Yu SHANG
Progress in Biochemistry and Biophysics 2025;52(10):2550-2567
Diabetic cardiomyopathy is a distinct form of cardiomyopathy that can lead to heart failure, arrhythmias, cardiogenic shock, and sudden death. It has become a major cause of mortality in diabetic patients. The pathogenesis of diabetic cardiomyopathy is complex, involving increased oxidative stress, activation of inflammatory responses, disturbances in glucose and lipid metabolism, accumulation of advanced glycation end products (AGEs), abnormal autophagy and apoptosis, insulin resistance, and impaired intracellular Ca2+ homeostasis. Recent studies have shown that adenosine monophosphate-activated protein kinase (AMPK) plays a crucial protective role by lowering blood glucose levels, promoting lipolysis, inhibiting lipid synthesis, and exerting antioxidant, anti-inflammatory, anti-apoptotic, and anti-ferroptotic effects. It also enhances autophagy, thereby alleviating myocardial injury under hyperglycemic conditions. Consequently, AMPK is considered a key protective factor in diabetic cardiomyopathy. As part of diabetes prevention and treatment strategies, both pharmacological and exercise interventions have been shown to mitigate diabetic cardiomyopathy by modulating the AMPK signaling pathway. However, the precise regulatory mechanisms, optimal intervention strategies, and clinical translation require further investigation. This review summarizes the role of AMPK in the prevention and treatment of diabetic cardiomyopathy through drug and/or exercise interventions, aiming to provide a reference for the development and application of AMPK-targeted therapies. First, several classical AMPK activators (e.g., AICAR, A-769662, O-304, and metformin) have been shown to enhance autophagy and glucose uptake while inhibiting oxidative stress and inflammatory responses by increasing the phosphorylation of AMPK and its downstream target, mammalian target of rapamycin (mTOR), and/or by upregulating the gene expression of glucose transporters GLUT1 and GLUT4. Second, many antidiabetic agents (e.g., teneligliptin, liraglutide, exenatide, semaglutide, canagliflozin, dapagliflozin, and empagliflozin) can promote autophagy, reverse excessive apoptosis and autophagy, and alleviate oxidative stress and inflammation by enhancing AMPK phosphorylation and its downstream targets, such as mTOR, or by increasing the expression of silent information regulator 1 (SIRT1) and peroxisome proliferator-activated receptor‑α (PPAR‑α). Third, certain anti-anginal (e.g., trimetazidine, nicorandil), anti-asthmatic (e.g., farrerol), antibacterial (e.g., sodium houttuyfonate), and antibiotic (e.g., minocycline) agents have been shown to promote autophagy/mitophagy, mitochondrial biogenesis, and inhibit oxidative stress and lipid accumulation via AMPK phosphorylation and its downstream targets such as protein kinase B (PKB/AKT) and/or PPAR‑α. Fourth, natural compounds (e.g., dihydromyricetin, quercetin, resveratrol, berberine, platycodin D, asiaticoside, cinnamaldehyde, and icariin) can upregulate AMPK phosphorylation and downstream targets such as AKT, mTOR, and/or the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), thereby exerting anti-inflammatory, anti-apoptotic, anti-pyroptotic, antioxidant, and pro-autophagic effects. Fifth, moderate exercise (e.g., continuous or intermittent aerobic exercise, aerobic combined with resistance training, or high-intensity interval training) can activate AMPK and its downstream targets (e.g., acetyl-CoA carboxylase (ACC), GLUT4, PPARγ coactivator-1α (PGC-1α), PPAR-α, and forkhead box protein O3 (FOXO3)) to promote fatty acid oxidation and glucose uptake, and to inhibit oxidative stress and excessive mitochondrial fission. Finally, the combination of liraglutide and aerobic interval training has been shown to activate the AMPK/FOXO1 pathway, thereby reducing excessive myocardial fatty acid uptake and oxidation. This combination therapy offers superior improvement in cardiac dysfunction, myocardial hypertrophy, and fibrosis in diabetic conditions compared to liraglutide or exercise alone.
2.Randomized, double-blind, parallel-controlled, multicenter, equivalence clinical trial of Jiuwei Xifeng Granules(Os Draconis replaced by Ostreae Concha) for treating tic disorder in children.
Qiu-Han CAI ; Cheng-Liang ZHONG ; Si-Yuan HU ; Xin-Min LI ; Zhi-Chun XU ; Hui CHEN ; Ying HUA ; Jun-Hong WANG ; Ji-Hong TANG ; Bing-Xiang MA ; Xiu-Xia WANG ; Ai-Zhen WANG ; Meng-Qing WANG ; Wei ZHANG ; Chun WANG ; Yi-Qun TENG ; Yi-Hui SHAN ; Sheng-Xuan GUO
China Journal of Chinese Materia Medica 2025;50(6):1699-1705
Jiuwei Xifeng Granules have become a Chinese patent medicine in the market. Because the formula contains Os Draconis, a top-level protected fossil of ancient organisms, the formula was to be improved by replacing Os Draconis with Ostreae Concha. To evaluate whether the improved formula has the same effectiveness and safety as the original formula, a randomized, double-blind, parallel-controlled, equivalence clinical trial was conducted. This study enrolled 288 tic disorder(TD) of children and assigned them into two groups in 1∶1. The treatment group and control group took the modified formula and original formula, respectively. The treatment lasted for 6 weeks, and follow-up visits were conducted at weeks 2, 4, and 6. The primary efficacy endpoint was the difference in Yale global tic severity scale(YGTSS)-total tic severity(TTS) score from baseline after 6 weeks of treatment. The results showed that after 6 weeks of treatment, the declines in YGTSS-TSS score showed no statistically significant difference between the two groups. The difference in YGTSS-TSS score(treatment group-control group) and the 95%CI of the full analysis set(FAS) were-0.17[-1.42, 1.08] and those of per-protocol set(PPS) were 0.29[-0.97, 1.56], which were within the equivalence boundary [-3, 3]. The equivalence test was therefore concluded. The two groups showed no significant differences in the secondary efficacy endpoints of effective rate for TD, total score and factor scores of YGTSS, clinical global impressions-severity(CGI-S) score, traditional Chinese medicine(TCM) response rate, or symptom disappearance rate, and thus a complete evidence chain with the primary outcome was formed. A total of 6 adverse reactions were reported, including 4(2.82%) cases in the treatment group and 2(1.41%) cases in the control group, which showed no statistically significant difference between the two groups. No serious suspected unexpected adverse reactions were reported, and no laboratory test results indicated serious clinically significant abnormalities. The results support the replacement of Os Draconis by Ostreae Concha in the original formula, and the efficacy and safety of the modified formula are consistent with those of the original formula.
Adolescent
;
Child
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Child, Preschool
;
Female
;
Humans
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Male
;
Double-Blind Method
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Drugs, Chinese Herbal/therapeutic use*
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Tic Disorders/drug therapy*
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Treatment Outcome
3.Effect and mechanism of Bufei Decoction on improving Klebsiella pneumoniae pneumonia in rats by regulating IL-17 signaling pathway.
Li-Na HUANG ; Zheng-Ying QIU ; Xiang-Yi PAN ; Chen LIU ; Si-Fan LI ; Shao-Guang GE ; Xiong-Wei SHI ; Hao CAO ; Rui-Hua XIN ; Fang-di HU
China Journal of Chinese Materia Medica 2025;50(11):3097-3107
Based on the interleukin-17(IL-17) signaling pathway, this study explores the effect and mechanism of Bufei Decoction on Klebsiella pneumoniae pneumonia in rats. SD rats were randomly divided into the control group, model group, Bufei Decoction low-dose group(6.68 g·kg~(-1)·d~(-1)), Bufei Decoction high-dose group(13.36 g·kg~(-1)·d~(-1)), and dexamethasone group(1.04 mg·kg~(-1)·d~(-1)), with 10 rats in each group. A pneumonia model was established by tracheal drip injection of K. pneumoniae. After successful model establishment, the improvement in lung tissue damage was observed following drug administration. Core targets and signaling pathways were screened using transcriptomics techniques. Real-time fluorescence quantitative polymerase chain reaction was used to detect the mRNA expression of core targets interleukin-6(IL-6), interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α), and chemokine CXC ligand 6(CXCL6). Western blot was used to assess key proteins in the IL-17 signaling pathway, including interleukin-17A(IL-17A), nuclear transcription factor-κB activator 1(Act1), tumor necrosis factor receptor-associated factor 6(TRAF6), and downstream phosphorylated p38 mitogen-activated protein kinase(p-p38 MAPK), and phosphorylated nuclear factor-κB p65(p-NF-κB p65). Apoptosis of lung tissue cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling(TUNEL). The results showed that, compared with the control group, the model group exhibited significant pathological damage in lung tissue. The mRNA expression of IL-6, IL-1β, TNF-α, and CXCL6, as well as the protein levels of IL-17A, Act1, TRAF6, p-p38 MAPK/p38 MAPK, and p-NF-κB p65/NF-κB p65, were significantly increased, and the number of apoptotic cells was notably higher, indicating successful model establishment. Compared with the model group, both low-and high-dose groups of Bufei Decoction showed reduced pathological damage in lung tissue. The mRNA expression levels of IL-6, IL-1β, TNF-α, and CXCL6, and the protein levels of IL-17A, Act1, TRAF6, p-p38 MAPK/p38 MAPK, and p-NF-κB p65/NF-κB p65, were significantly decreased, with a significant reduction in apoptotic cells in the high-dose group. In conclusion, Bufei Decoction can effectively improve lung tissue damage and reduce inflammation in rats with K. pneumoniae. The mechanism may involve the regulation of the IL-17 signaling pathway and the reduction of apoptosis.
Animals
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Interleukin-17/metabolism*
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Drugs, Chinese Herbal/administration & dosage*
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Rats, Sprague-Dawley
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Signal Transduction/drug effects*
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Rats
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Male
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Klebsiella pneumoniae/physiology*
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Klebsiella Infections/immunology*
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Humans
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Lung/drug effects*
4.Comparison of short-term clinical efficacy between CO external fixation and internal fixation with steel plate in the treatment of unstable distal radius fractures.
Min-Rui FU ; Chang-Long SHI ; Yong-Zhong CHENG ; Ming-Ming MA ; Zheng-Lin NIU ; Hai-Xiang SUN ; Jing-Hua GAO ; Zhong-Kai WU ; Yi-Ming XU
China Journal of Orthopaedics and Traumatology 2025;38(1):10-17
OBJECTIVE:
To evaluate the short-term clinical efficacy of external fixation and internal fixation with steel plate in the treatment of unstable distal radius fractures (AO-23C type), based on the principles of Chinese osteosynthesis (CO).
METHODS:
Forty-eight patients with unstable distal radius fractures between January 2022 and February 2023 were retrospectively analyzed and divided into the CO external fixation group and internal fixation group. CO external fixation group consisted of 25 patients, including 7 males and 18 females, aged from 37 to 56 years old with an average of ( 52.6±11.3) years old. Among them, there were 7 patients of traffic accidents and 18 patients of falls, resulting in a total of 25 patients of closed fractures and no open fractures, the treatment was conducted using closed reduction and CO external fixation. The internal fixation group consisted of 23 patients, comprising 8 males and 15 females, age ranged from 41 to 59 years old, with an average age of(53.3±13.7) years old. Among them, 8 patients resulted from car accidents while the remaining 15 patients were caused by falls. All 23 patients were closed fractures without any open fractures observed. The technique of open reduction and internal fixation with steel plate was employed. The perioperative data, including injury-operation time, operation duration, blood loss, and length of hospital stay, were assessed in both groups. Additionally, the QuickDASH score and visual analogue scale (VAS) were evaluated. Range of motion and grip strength assessment, imaging findings such as palmar inclination angle, ulnar declination angle, radius length, articular surface step, intra-articular space measurements were also examined along with any complications.
RESULTS:
The follow-up duration ranged from 0 to 24 months, with an average duration of (16.0±3.8) months. The CO external fixation exhibited significantly shorter time from injury to operation (2.4±3.3) d vs (7.4±3.7) d, shorter operation duration (56.27±15.23) min vs (74.10±5.26) min, lower blood loss (14.52±6.54) ml vs (32.32±10.03) ml, and reduced hospitalization days (14.04±3.24 )d vs (16.45±3.05) d compared to the internal fixation group (P<0.05). The QuickDASH score at 12 months post-operation was (8.21±1.64) in the CO external fixation group, while no significant difference was observed in the internal fixation group (7.04±3.64), P>0.05. There were no statistically significant differences in VAS between two groups at 6 weeks, as well as 1 and 3 months post-surgery (P>0.05). Additionally, there were no significant disparities observed in terms of range of motion and grip strength between two groups at the 2-year follow-up after the operation (P>0.05). After 12 months of surgery, the CO external fixation group exhibited a significantly smaller palmar inclination angle (17.90±2.18) ° vs (19.87±3.21) °, reduced articular surface step (0.11±0.03) mm vs (0.17±0.02) mm, and shorter radius length (8.16±1.11) mm compared to the internal fixation group (9.59±1.02) mm, P<0.05. The ulnar deviation angle and intra-articular space did not show any significant difference between two groups (P>0.05). The reduced fell within the allowable range between the CO external fixation group (23 out of 25 cases) and the internal fixation group (21 out of 23 cases) was not statistically significant (P=0.29). There was no significant difference in complications between the two groups(P>0.05).
CONCLUSION
Both the CO external fixation and open reduction with plate internal fixation demonstrate clinical efficacy in managing unstable distal radius fractures. The CO external fixation offers advantages in shorter injury-to-operation times, reduced intraoperative blood loss, and decreased surgical durations, while radial shortening is more effectively controlled by internal fixation.
Humans
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Male
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Female
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Middle Aged
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Radius Fractures/physiopathology*
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Adult
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Bone Plates
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Fracture Fixation, Internal/methods*
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External Fixators
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Retrospective Studies
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Fracture Fixation/methods*
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Wrist Fractures
5.Impact of human papillomavirus and coinfection with other sexually transmitted pathogens on male infertility.
Xin FAN ; Ya XU ; Li-Feng XIANG ; Lu-Ping LIU ; Jin-Xiu WAN ; Qiu-Ting DUAN ; Zi-Qin DIAN ; Yi SUN ; Ze WU ; Yun-Hua DONG
Asian Journal of Andrology 2025;27(1):84-89
This study primarily aimed to investigate the prevalence of human papillomavirus (HPV) and other common pathogens of sexually transmitted infections (STIs) in spermatozoa of infertile men and their effects on semen parameters. These pathogens included Ureaplasma urealyticum, Ureaplasma parvum, Chlamydia trachomatis, Mycoplasma genitalium , herpes simplex virus 2, Neisseria gonorrhoeae, Enterococcus faecalis, Streptococcus agalactiae, Pseudomonas aeruginosa , and Staphylococcus aureus . A total of 1951 men of infertile couples were recruited between 23 March 2023, and 17 May 2023, at the Department of Reproductive Medicine of The First People's Hospital of Yunnan Province (Kunming, China). Multiplex polymerase chain reaction and capillary electrophoresis were used for HPV genotyping. Polymerase chain reaction and electrophoresis were also used to detect the presence of other STIs. The overall prevalence of HPV infection was 12.4%. The top five prevalent HPV subtypes were types 56, 52, 43, 16, and 53 among those tested positive for HPV. Other common infections with high prevalence rates were Ureaplasma urealyticum (28.3%), Ureaplasma parvum (20.4%), and Enterococcus faecalis (9.5%). The prevalence rates of HPV coinfection with Ureaplasma urealyticum, Ureaplasma parvum, Chlamydia trachomatis, Mycoplasma genitalium , herpes simplex virus 2, Neisseria gonorrhoeae, Enterococcus faecalis, Streptococcus agalactiae , and Staphylococcus aureus were 24.8%, 25.4%, 10.6%, 6.4%, 2.4%, 7.9%, 5.9%, 0.9%, and 1.3%, respectively. The semen volume and total sperm count were greatly decreased by HPV infection alone. Coinfection with HPV and Ureaplasma urealyticum significantly reduced sperm motility and viability. Our study shows that coinfection with STIs is highly prevalent in the semen of infertile men and that coinfection with pathogens can seriously affect semen parameters, emphasizing the necessity of semen screening for STIs.
Humans
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Male
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Infertility, Male/epidemiology*
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Coinfection/microbiology*
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Papillomavirus Infections/virology*
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Adult
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Sexually Transmitted Diseases/complications*
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China/epidemiology*
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Staphylococcus aureus/isolation & purification*
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Chlamydia trachomatis/isolation & purification*
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Prevalence
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Mycoplasma genitalium/isolation & purification*
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Ureaplasma urealyticum/isolation & purification*
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Neisseria gonorrhoeae/isolation & purification*
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Enterococcus faecalis/isolation & purification*
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Streptococcus agalactiae/isolation & purification*
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Herpesvirus 2, Human/genetics*
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Pseudomonas aeruginosa/isolation & purification*
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Semen/virology*
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Sperm Motility
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Spermatozoa/microbiology*
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Human Papillomavirus Viruses
6.Efficacy and Safety of Juan Bi Pill with Add-on Methotrexate in Active Rheumatoid Arthritis: A 48-Week, Multicentre, Randomized, Double-Blind, Placebo-Controlled Trial.
Qing-Yun JIA ; Yi-Ru WANG ; Da-Wei SUN ; Jian-Chun MAO ; Luan XUE ; Xiao-Hua GU ; Xiang YU ; Xue-Mei PIAO ; Hao XU ; Qian-Qian LIANG
Chinese journal of integrative medicine 2025;31(2):99-107
OBJECTIVE:
To explore the efficacy and safety of Juan Bi Pill (JBP) in treatment of active rheumatoid arthritis (RA).
METHODS:
From February 2017 to May 2018, 115 participants from 4 centers were randomly divided into JBP group (57 cases) and placebo group (58 cases) in a 1:1 ratio using a random number table method. Participants received a dose of JBP (4 g, twice a day, orally) combined with methotrexate (MTX, 10 mg per week) or placebo (4 g, twice a day, orally) combined with MTX for 12 weeks. Participants were required with follow-up visits at 24 and 48 weeks, attending 7 assessment visits. Participants were undergo disease activity assessment 7 times (at baseline and 2, 4, 8, 12, 24, 48 weeks) and safety assessments 6 times (at baseline and 4, 8, 12, 24, 48 weeks). The primary endpoint was 28-joint Disease Activity Score (DAS28-ESR and DAS28-CRP). The secondary endpoints included American College of Rheumatology (ACR) criteria for 20% and 50% improvement (ACR20/50), Health Assessment Questionnaire Disability Index (HAQ-DI), clinical disease activity index (CDAI), visual analog scale (VAS), Short Form-36 (SF-36) score, Medial Outcomes Study (MOS) sleep scale score, serum erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), tender joint count, swollen joint count, and morning stiffness. The adverse reactions were observed during the treatment.
RESULTS:
After 12 weeks of treatment, DAS28-ESR and DAS28-CRP scores in both groups were lower than before treatment (both P<0.01), while the remission rate of DAS28-ESR and DAS28-CRP and low disease activity of JBP group were higher than those in the placebo group (both P<0.01). JBP demonstrated better efficacy on ACR20 and ACR50 compliance rate at 12 and 48 weeks comparing to placebo (all P<0.05). The CDAI and HAQ-DI score, pain VAS and global VAS change of RA patients and physicians, the serum ESR and CRP levels, and the number of tenderness and swelling joints were lower than before treatment at 4, 8, 12, 24, 48 weeks in both groups (P<0.05 or P<0.01), while the reduction of above indices in the JBP group was more obvious than those in the placebo group at 12 weeks (ESR and CRP, both P<0.05) or at 12 and 48 weeks (all P<0.01). There was no difference in adverse reactions between the 2 groups during treatment (P=0.75).
CONCLUSION
JBP combined with MTX could effectively reduce disease activity in patients with RA in active stage, reduce the symptoms of arthritis, and improve the quality of life, while ensuring safety, reliability, and fewer adverse effects. (Trial Registration: ClinicalTrials.gov, No. NCT02885597).
Humans
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Arthritis, Rheumatoid/drug therapy*
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Methotrexate/adverse effects*
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Female
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Double-Blind Method
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Male
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Middle Aged
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Treatment Outcome
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Drugs, Chinese Herbal/adverse effects*
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Drug Therapy, Combination
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Adult
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Antirheumatic Agents/adverse effects*
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Aged
7.Two new isocoumarins from cave-derived Metarhizium anisopliae NHC-M3-2
Rong-xiang WU ; Jie-lan GUO ; Hua HUANG ; Jing-jing LIAO ; Yi HAO ; Fan-dong KONG ; Li-man ZHOU ; Chao-jun ZHANG
Acta Pharmaceutica Sinica 2024;59(9):2588-2593
Extracting extracts of secondary metabolites from the karst cave fungus
8.Efficacy and safety of recombinant human anti-SARS-CoV-2 monoclonal antibody injection(F61 injection)in the treatment of patients with COVID-19 combined with renal damage:a randomized controlled exploratory clinical study
Ding-Hua CHEN ; Chao-Fan LI ; Yue NIU ; Li ZHANG ; Yong WANG ; Zhe FENG ; Han-Yu ZHU ; Jian-Hui ZHOU ; Zhe-Yi DONG ; Shu-Wei DUAN ; Hong WANG ; Meng-Jie HUANG ; Yuan-Da WANG ; Shuo-Yuan CONG ; Sai PAN ; Jing ZHOU ; Xue-Feng SUN ; Guang-Yan CAI ; Ping LI ; Xiang-Mei CHEN
Chinese Journal of Infection Control 2024;23(3):257-264
Objective To explore the efficacy and safety of recombinant human anti-severe acute respiratory syn-drome coronavirus 2(anti-SARS-CoV-2)monoclonal antibody injection(F61 injection)in the treatment of patients with coronavirus disease 2019(COVID-19)combined with renal damage.Methods Patients with COVID-19 and renal damage who visited the PLA General Hospital from January to February 2023 were selected.Subjects were randomly divided into two groups.Control group was treated with conventional anti-COVID-19 therapy,while trial group was treated with conventional anti-COVID-19 therapy combined with F61 injection.A 15-day follow-up was conducted after drug administration.Clinical symptoms,laboratory tests,electrocardiogram,and chest CT of pa-tients were performed to analyze the efficacy and safety of F61 injection.Results Twelve subjects(7 in trial group and 5 in control group)were included in study.Neither group had any clinical progression or death cases.The ave-rage time for negative conversion of nucleic acid of SARS-CoV-2 in control group and trial group were 3.2 days and 1.57 days(P=0.046),respectively.The scores of COVID-19 related target symptom in the trial group on the 3rd and 5th day after medication were both lower than those of the control group(both P<0.05).According to the clinical staging and World Health Organization 10-point graded disease progression scale,both groups of subjects improved but didn't show statistical differences(P>0.05).For safety,trial group didn't present any infusion-re-lated adverse event.Subjects in both groups demonstrated varying degrees of elevated blood glucose,elevated urine glucose,elevated urobilinogen,positive urine casts,and cardiac arrhythmia,but the differences were not statistica-lly significant(all P>0.05).Conclusion F61 injection has initially demonstrated safety and clinical benefit in trea-ting patients with COVID-19 combined with renal damage.As the domestically produced drug,it has good clinical accessibility and may provide more options for clinical practice.
9.Three 2,3-diketoquinoxaline alkaloids with hepatoprotective activity from Heterosmilax yunnanensis
Rong-rong DU ; Xin-yi GUO ; Wen-jie QIN ; Hua SUN ; Xiu-mei DUAN ; Xiang YUAN ; Ya-nan YANG ; Kun LI ; Pei-cheng ZHANG
Acta Pharmaceutica Sinica 2024;59(2):413-417
Three 2,3-diketoquinoxaline alkaloids were isolated from
10.IDH1R132H Mutant Glioma and Its Compensatory Mechanisms for Maintaining Telomeres
Si-Xiang YAN ; Yi-Fan LI ; Yao LI ; Yi-Xuan LI ; Xiang-Xiu LI ; Jin-Kai TONG ; Shu-Ting JIA ; Ju-Hua DAN
Progress in Biochemistry and Biophysics 2024;51(11):2845-2852
Isocitrate dehydrogenase 1 (IDH1) R132H is the most common mutated gene in grade II-III gliomas and oligodendrogliomas. Instead of activating telomerase (a reverse transcriptase which using RNA as a template to extend telomere length), the majority of IDH1R132H mutant glioma maintain telomere length through an alternative mechanism that relies on homologous recombination (HR), which is known as alterative lengthening of telomere (ALT).The phenotype of ALT mechanism include: ALT associated promyelocytic leukemia protein (PML) bodies (APBs); extrachromosomal telomeric DNA repeats such as C- and T-loops; telomeric sister chromatid exchange (T-SCE), etc. The mechanism of ALT activation is not fully understood. Recent studies have shown that mutation IDH1 contributes to ALT phenotype in glioma cells in at least three key ways. Firstly, the IDH1R132H mutation mediates RAP1 down-regulation leading to telomere dysfunction, thus ensuring persistent endogenous telomeric DNA damage, which is important for ALT activation. Spontaneous DNA damage at telomeres may provide a substrate for mutation break-induced replication (BIR)‑mediated ALT telomere lengthening, and it has been demonstrated that RAP1 inhibits telomeric repeat-containing RNA, transcribed from telomeric DNA repeat sequences (TERRA) transcription to down-regulate ALT telomere DNA replication stress and telomeric DNA damage, thereby inhibiting ALT telomere synthesis. Similarly, in ALT cells, knockdown of telomere-specific RNaseH1 nuclease triggers TERRA accumulation, which leads to increased replication pressure. Overexpression of RNaseH1, on the other hand, attenuates the recombination capacity of ALT telomeres, leading to telomere depletion, suggesting that RAP1 can regulate the level of replication pressure and thus ALT activity by controlling TERRA expression. Secondly, the IDH1R132H also alters the preference of the telomere damage repair pathway by down-regulating XRCC1, which inhibits the alternative non-homologous end joining (A-NHEJ) pathway at telomeres and alters cellular preference for the HR pathway to promote ALT. Finally, the IDH1R132H has a decreased affinity for isocitric acid and NADP+ and an increased affinity for α ketoglutarate (α‑KG) and NADPH, so that the mutant IDH1R132H catalyzes the hydrogenation of α‑KG to produce 2-hydroxyglutarate (2-HG)in a NADPH-dependent manner. Because 2-HG is structurally similar to α‑KG, which maintains the trimethylation level of H3k9me3 by competitively inhibiting the activity of the α‑KG-dependent histone demethylase KDM4B, and recruits heterochromatin protein HP1α to heterochromatinize telomeres, and promote ALT phenotypes in cooperation with the inactivating of ATRX. In addition, it has been shown that APBs contain telomeric chromatin, which is essentially heterochromatin, and HP1α is directly involved in the formation of APBs. Based on these studies, this article reviews the mechanism of IDH1R132H mediated telomere dysfunction and the preference of DNA repair pathway at telomeres in cooperate with ATRX loss to promote ALT, which may provide references for clinical targeted therapy of IDH1R132H mutant glioma.

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