The present study aimed to investigate the effects of eccentric treadmill exercise on adaptive hypertrophy of skeletal muscle in rats. Thirty-two 3-month-old Sprague Dawley (SD) rats were selected and randomly assigned to one of the four groups based on their body weights: 2-week quiet control group (2C), 2-week downhill running exercise group (2E), 4-week quiet control group (4C), and 4-week downhill running exercise group (4E). The downhill running protocol for rats in the exercise groups involved slope of -16°, running speed of 16 m/min, training duration of 90 min, and 5 training sessions per week. Twenty-four hours after the final session of training, all the four groups of rats underwent an exhaustion treadmill exercise. After resting for 48 h, all the rats were euthanized and their gastrocnemius muscles were harvested for analysis. HE staining was used to measure the cross-sectional area (CSA) and diameter of muscle fibers. Transmission electron microscope was used to observe the ultrastructural changes in muscle fibers. Purithromycin surface labeling translation method was used to measure protein synthesis rate. Immunofluorescence double labeling was used to detect the colocalization levels of lysosomal-associated membrane protein 2 (Lamp2)-leucyl-tRNA synthetase (LARS) and Lamp2-mammalian target of rapamycin (mTOR). Western blot was used to measure the protein expression levels of myosin heavy chain (MHC) IIb and LARS, as well as the phosphorylation levels of mTOR, p70 ribosomal protein S6 kinase (p70S6K), and eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1). The results showed that, compared with the 2C group rats, the 2E group rats showed significant increases in wet weight of gastrocnemius muscle, wet weight/body weight ratio, running distance, running time, pre- and post-exercise blood lactate levels, myofibrillar protein content, colocalization levels of Lamp2-LARS and Lamp2-mTOR, and LARS protein expression. Besides these above changes, compared with the 4C group, the 4E group further exhibited significantly increased fiber CSA, fiber diameter, protein synthesis rate, and phosphorylation levels of mTOR, p70S6K, and 4E-BP1. Compared with the quiet control groups, the exercise groups exhibited ultrastructural damage of rat gastrocnemius muscle, which was more pronounced in the 4E group. These findings suggest that eccentric treadmill exercise may promote mTOR translocation to lysosomal membrane, activating mTOR signaling via up-regulating LARS expression. This, in turn, increases protein synthesis rate through the mTOR-p70S6K-4E-BP1 signaling pathway, promoting protein deposition and inducing adaptive skeletal muscle hypertrophy. Although the ultrastructural changes of skeletal muscle are more pronounced, the relatively long training cycles during short-term exercise periods have a more significant effect on promoting gastrocnemius muscle protein synthesis and adaptive hypertrophy.
Animals ; Rats, Sprague-Dawley ; Physical Conditioning, Animal/physiology* ; Rats ; Muscle, Skeletal/metabolism* ; TOR Serine-Threonine Kinases/metabolism* ; Male ; Hypertrophy ; Adaptation, Physiological/physiology* ; Adaptor Proteins, Signal Transducing/metabolism* ; Ribosomal Protein S6 Kinases, 70-kDa/metabolism* ; Intracellular Signaling Peptides and Proteins

OBJECTIVES: To analyze the clinical characteristics of diffuse panbronchiolitis (DPB) in children and to enhance the clinical diagnosis and treatment of this disease. METHODS: A retrospective analysis was conducted on the clinical data of 6 children diagnosed with DPB who were hospitalized at The First Affiliated Hospital of Guangzhou Medical University from January 2011 to December 2019. RESULTS: Among the 6 patients, there were 2 males and 4 females; the age at diagnosis ranged from 7 to 12 years. All patients presented with cough, sputum production, and exertional dyspnea, and all had a history of sinusitis. Two cases showed positive serum cold agglutinin tests, and 5 cases exhibited pathological changes consistent with chronic bronchiolitis. High-resolution chest CT in all patients revealed centrilobular nodules diffusely distributed throughout both lungs with a tree-in-bud appearance. Five patients received low-dose azithromycin maintenance therapy, but 3 showed inadequate treatment response. After empirical anti-tuberculosis treatment, non-tuberculous Mycobacteria were found in the bronchoalveolar lavage fluid. Follow-up over 2 years showed 1 case cured, 3 cases significantly improved, and 2 cases partially improved. CONCLUSIONS The clinical presentation of DPB is non-specific and can easily lead to misdiagnosis. In cases where DPB is clinically diagnosed but does not show improvement with low-dose azithromycin treatment, special infections should be considered.
Humans ; Male ; Female ; Bronchiolitis/drug therapy* ; Retrospective Studies ; Child ; Haemophilus Infections/diagnosis*

Objective:To analyze the effect of recombinant human thrombopoietin(rhTPO)on platelet(PLT)reconstitution after autologous peripheral blood stem cell transplantation(APBSCT)in patients with multiple myeloma(MM).Methods:The clinical data of 147 MM patients who were diagnosed in the First Affiliated Hospital of Soochow University and received APBSCT as the first-line therapy were retrospectively analyzed.According to whether rhTPO was used during APBSCT,the patients were divided into rhTPO group(80 cases)and control group(67 cases).The time of PLT engraftment,blood product infusion requirements,the proportion of patients with PLT recovery to ≥ 50 × 109/L and ≥ 100 × 109/L at+14 days and+100 days after transplantation,and adverse reactions including the incidence of bleeding were compared between the two groups.Results:There were no significant differences between the two groups in sex,age,M protein type,PLT count at the initial diagnosis,median duration of induction therapy before APBSCT,and number of CD34+cells reinfused(all P＞0.05).The median time of PLT engraftment in the rhTPO group was 10(6-14)days,which was shorter than 11(8-23)days in the control group(P＜0.001).The median PLT transfusion requirement in the rhTPO group during APBSCT was 15(0-50)U,which was less than 20(0-80)U in the control group(P=0.001).At+14 days after transplantation,the proportions of patients with PLT 2 50 × 109/L in the rhTPO group and the control group were 66.3％and 52.2％,while the proportions of patients with PLT ≥ 100 × 109/L were 23.8％and 11.9％,respectively,with no significant differences(all P＞0.05).At+100 days after transplantation,the proportion of patients with PLT ≥ 50 × 109/L in rhTPO group and control group was 96.3％and 89.6％,respectively(P＞0.05),but the proportion of patients with PLT ≥ 100 × 109/L in rhTPO group was higher than that in control group(75.0％vs 55.2％,P=0.012).There was no difference in the overall incidence of bleeding events in different locations during period of low PLT level of patients between the two groups.In rhTPO group,the rhTPO administration was well tolerated,and the incidences of abnormal liver and kidney function and infection were similar to those in the control group.Conclusion:When MM patients undergo first-line APBSCT,subcutaneous injection of rhTPO can shorten the time of platelet engraftment,reduce the transfusion volume of blood products,and be well tolerated,moreover,more patients have achieve a high level of PLT recovery after transplantation,which is very important for ensuring the safety of APBSCT and maintenance therapy.

Objective To establish an evaluation system of pathogen detection rate of hospitalized patients before antimicrobial treatment based on process and outcome indicators,and study its application effect.Methods Hospi-talized patients with therapeutic antimicrobial treatment in a tertiary first-class hospital from July 2022 to June 2023 were selected as the study objects.Difference in process and outcome indicators were compared between before(Ju-ly-December 2022,control group)and after(January-June 2023,intervention group)the implementation of inter-vention in the evaluation system for pathogen detection rate of hospitalized patients before antimicrobial treatment.Results 41 577 and 27 052 hospitalized patients received therapeutic antimicrobial agents were included in the inter-vention group and control group,respectively.Pathogen detection rate and the accurate pathogen detection rate in the intervention group were both higher than those in the control group(74.2％vs 62.8％and 90.3％vs 82.5％,respectively),both with statistically significant differences(both P＜0.001).The goal achievement rate and im-provement rate for pathogen detection rate were 237.5％and 18.2％respectively,the goal achievement rate and im-provement rate for accurate pathogen detection rate were 104.0％and 9.5％respectively.For the process indica-tors,the conformity rate of detection and diagnosis,accurate collection rate,timely transfer rate,acceptance rate of pathogen specimens in the intervention group were all higher than those in the control group,differences were all statistically significant(all P＜0.001).For the outcome indicators,detection rates of targeted indicators and blood culture specimens,pathogen detection rate before treatment of restricted and special grade antimicrobial agent,as well as detection rate of sterile body fluid specimens in the intervention group were all higher than those in the con-trol group,with statistical significance(all P＜0.05).In addition,the positive rate of blood culture specimens in-creased from 18.5％before intervention to 21.7％after intervention,with statistically significant difference(P＜0.05).Conclusion The establishment of indicator evaluation system can improve the detection rate and accurate detection rate of pathogens before antimicrobial treatment,as well as the management quality and connotation of indicators.

Objective:To understand the effect of vitamin B1 on lymphocyte function in simulated microgravity.Methods:Splenocytes of mice were isolated,and the rotatary cell culture system was used to simulate microgravity.Lymphocytes were stimulated with mitotic agents Concanavalin A,and cells were treated with different concentrations of vitamin B1,proliferation indexes of lympho-cytes and levels of cytokines in supernatant were detected.Results:Simulated microgravity could inhibit proliferation of splenic lym-phocytes,and decrease levels of cytokines,while vitamin B1 could promote lymphocyte proliferation and cytokines production in cells cultured in simulated microgravity in a dose dependent manner.Conclusion:Vitamin B1 may attenuate the inhibitory effect of simulated microgravity on lymphocytes by regulating cell proliferation and secretion of cytokines.

Objective:To understand the effect of collagen peptides on the function of mouse lymphocytes under simulated microgravity.Methods:The splenocytes of mice were isolated,and the rotary cell culture system was used to simulate the microgravity.The T lymphocytes were stimulated with mitotic agents,concanavalin A(ConA),and the cells were treated with different concentrations of collagen peptides.The proliferation of lymphocytes and the levels of cytokines in the supernatant were detected.Results:Simulated microgravity could inhibit the proliferation of spleen T lymphocytes and decrease the level of cytokines in the supernatant.Collagen peptides could promote the lymphocyte proliferation and cytokine production in cells cultured under simulated microgravity.Conclusion:Collagen peptides may attenuate the inhibitory effect of simulated microgravity on T lymphocytes by regulating the cell proliferation and the secretion of cytokines.

Age-related sarcopenia is a degenerative disease characterized by the decline in skeletal muscle mass and function during the aging process. Anabolic resistance, which refers to the diminished response of skeletal muscle to anabolic stimulation from leucine and other nutrients, is a significant contributing factor to its development. Recent studies have suggested that large neutral amino acid-transporter 1 (LAT1/SLC7A5) may play an important role in enhancing leucine's effects on protein synthesis in aging skeletal muscle. In this paper, the structure and function of LAT1 and its key molecules regulating aging skeletal muscle protein synthesis were reviewed, and the potential relationship between LAT1, as a transmembrane transporter of leucine, and protein synthesis in aging skeletal muscle was analyzed. The aim is to explore new mechanisms and insights for prevention and treatment of age-related sarcopenia, and provide reference for the application of relevant targets in clinical translational medicine.
Humans ; Leucine/metabolism* ; Muscle, Skeletal/metabolism* ; Aging/metabolism* ; Large Neutral Amino Acid-Transporter 1/metabolism* ; Protein Biosynthesis ; Sarcopenia/metabolism* ; Animals ; Muscle Proteins/biosynthesis*

Objective:In order to explore the impact of corona virus disease 2019(COVID-19)on the hospitalization of children with bronchiolitis and to improve clinicians′ understanding of the characteristics of bronchiolitis during the COVID-19 epidemic.Methods:This was a multicenter clinical study, and the data have been collected from 23 children′s medical centers in China.All the clinical data were retrospectively collected from children with bronchiolitis who were hospitalized at each study center from January 1, 2019 to December 31, 2021.The results included gender, age at hospitalization, length of stay, respiratory syncytial virus(RSV) test results, severity rating, ICU treatment, and the total number of children hospitalized with respiratory tract infection during the same period.The clinical data of children with bronchiolitis in 2019 before COVID-19 epidemic and in 2020、2021 during COVID-19 epidemic were statistically analyzed and compared.Results:According to a summary of data provided by 23 children′s medical centers, there were 4 909 cases of bronchiolitis in 2019, 2 654 cases in 2020, and 3 500 cases in 2021.Compared with 2019, the number of bronchiolitis cases decreased by 45.94% in 2020 and 28.70% in 2021.In 2019, 2020 and 2021, there were no significant differences in gender ratio, age, and duration of hospitalization.Compared with 2019, the ratio of bronchiolitis to the total number of hospitalizations for respiratory tract infection decreased significantly in 2020 and 2021( χ2=12.762, P<0.05; χ2=84.845, P<0.05).The proportion of moderate to severe bronchiolitis cases in both 2020 and 2021 was lower than that in 2019, and the difference was statistically significant ( χ2=4.054, P<0.05; χ2=8.109, P<0.05).There was no statistically significant difference in the proportion of bronchiolitis cases requiring ICU treatment between 2019, 2020, and 2021 ( χ2=1.914, P>0.05).In 2019, a total of 52.60%(2 582/4 909) of children with bronchiolitis underwent RSV pathogen testing, and among them, there were 708 cases with RSV positive, accounting for 28.00%.In 2020, 54.14%(1 437/2 654) of children with bronchiolitis underwent RSV pathogen testing, and there were 403 cases with RSV positive, accounting for 28.04%.In 2021, 66.80%(2 238/3 500) of children with bronchiolitis underwent RSV pathogen testing, and there were 935 cases with RSV positive, accounting for 41.78%.Compared with 2019 and 2020, the RSV positive rate in 2021 showed a significant increase( χ2=99.673, P<0.05; χ2=71.292, P<0.05). Conclusion:During the COVID-19 epidemic, the implementation of epidemic prevention and control measures reduced the hospitalization rate and severity of bronchiolitis, but did not reduce the positive rate of RSV detection.

Humans ; Multiple Myeloma/genetics* ; Neoplasm, Residual/diagnosis* ; Flow Cytometry ; High-Throughput Nucleotide Sequencing