ObjectiveMitochondria are not only the central organelles responsible for cellular energy metabolism but also play essential roles in regulating cell cycle progression and cytoskeletal dynamics. In recent years, accumulating evidence has demonstrated that mitochondrial homeostasis is closely associated with mitotic progression and cytokinesis. Schizosaccharomyces pombe serves as a classical and well-established model organism. Because its cell cycle regulatory mechanisms are highly conserved throughout evolution, its genetic background is clearly defined, and experimental manipulation is efficient and convenient, it has been extensively applied in studies of cell growth, division, and reproductive mechanisms. The SPBC1604.04 gene encodes a previously uncharacterized mitochondrial carrier protein in Schizosaccharomyces pombe. This gene is located on chromosome II and spans 1 018 base pairs in length. It encodes a protein consisting of 238 amino acids with a predicted molecular mass of approximately 31.03 ku. Bioinformatic analysis predicts that this protein is responsible for the transport of thiamine pyrophosphate (TPP) into mitochondria. However, the effects of SPBC1604.04 gene deletion on mitotic cell dynamics under different temperature conditions have not been fully elucidated. MethodsThe SPBC1604.04 deletion strain of Schizosaccharomyces pombe was used as the experimental model. Fluorescent protein markers were constructed in the deletion background to label mitochondria, microtubules, actin, myosin, the nuclear envelope, and chromosomes. Live-cell imaging was performed using a TCS-SP8 laser scanning confocal microscope under normal temperature conditions (25℃) and heat stress conditions (37℃). Time-lapse microscopy was applied to dynamically monitor mitochondrial morphology and distribution, spindle assembly and elongation, chromosome segregation, as well as the formation and constriction of the actomyosin ring during cytokinesis. ImageJ software was used for quantitative measurements, including microtubule length during mitosis, spindle length at different mitotic stages, mitochondrial fluorescence intensity as an indicator of mitochondrial content, actomyosin ring length, nuclear envelope area, and chromosome segregation timing. Statistical analyses were conducted to compare phenotypic differences between the wild-type and SPBC1604.04 deletion strains at both temperature conditions. Through these analyses, we systematically investigated the impact of SPBC1604.04 deletion on mitotic cell dynamics in fission yeast under both normal physiological conditions and temperature stress. ResultsAt 25℃, compared with wild-type cells, the SPBC1604.04Δ strain exhibited a pronounced tendency toward mitochondrial fragmentation, accompanied by abnormal mitochondrial content and a significant reduction in mitochondrial fluorescence intensity. These observations suggest impaired mitochondrial homeostasis under normal growth conditions. In addition, the constriction time of actomyosin ring during cytokinesis was markedly prolonged, indicating that deletion of SPBC1604.04 affects the dynamics of the contractile machinery. However, no obvious defects were observed in spindle assembly, spindle elongation, or chromosome segregation. Under heat stress at 37℃, mitochondrial morphology in the SPBC1604.04Δ strain showed a tendency to recover toward a continuous tubular network structure. Mitochondrial content was restored, fluorescence intensity increased, and the constriction time of the actomyosin ring returned to levels comparable to those of wild-type cells. These results indicate that the mitotic defects observed at normal temperature are partially or fully alleviated under heat stress conditions. ConclusionThis study demonstrates that deletion of the SPBC1604.04 gene leads to abnormal mitochondrial content in Schizosaccharomyces pombe. The mitochondrial carrier protein SPBC1604.04 participates in regulating actomyosin ring constriction during mitosis but does not appear to be directly involved in the regulation of spindle dynamics or chromosome segregation. Our findings provide key experimental evidence for understanding the functional link between the SPBC1604.04 gene, mitochondrial homeostasis, and mitotic regulation.

ObjectiveMitochondria are not only the central organelles responsible for cellular energy metabolism but also play essential roles in regulating cell cycle progression and cytoskeletal dynamics. In recent years, accumulating evidence has demonstrated that mitochondrial homeostasis is closely associated with mitotic progression and cytokinesis. Schizosaccharomyces pombe serves as a classical and well-established model organism. Because its cell cycle regulatory mechanisms are highly conserved throughout evolution, its genetic background is clearly defined, and experimental manipulation is efficient and convenient, it has been extensively applied in studies of cell growth, division, and reproductive mechanisms. The SPBC1604.04 gene encodes a previously uncharacterized mitochondrial carrier protein in Schizosaccharomyces pombe. This gene is located on chromosome II and spans 1 018 base pairs in length. It encodes a protein consisting of 238 amino acids with a predicted molecular mass of approximately 31.03 ku. Bioinformatic analysis predicts that this protein is responsible for the transport of thiamine pyrophosphate (TPP) into mitochondria. However, the effects of SPBC1604.04 gene deletion on mitotic cell dynamics under different temperature conditions have not been fully elucidated. MethodsThe SPBC1604.04 deletion strain of Schizosaccharomyces pombe was used as the experimental model. Fluorescent protein markers were constructed in the deletion background to label mitochondria, microtubules, actin, myosin, the nuclear envelope, and chromosomes. Live-cell imaging was performed using a TCS-SP8 laser scanning confocal microscope under normal temperature conditions (25℃) and heat stress conditions (37℃). Time-lapse microscopy was applied to dynamically monitor mitochondrial morphology and distribution, spindle assembly and elongation, chromosome segregation, as well as the formation and constriction of the actomyosin ring during cytokinesis. ImageJ software was used for quantitative measurements, including microtubule length during mitosis, spindle length at different mitotic stages, mitochondrial fluorescence intensity as an indicator of mitochondrial content, actomyosin ring length, nuclear envelope area, and chromosome segregation timing. Statistical analyses were conducted to compare phenotypic differences between the wild-type and SPBC1604.04 deletion strains at both temperature conditions. Through these analyses, we systematically investigated the impact of SPBC1604.04 deletion on mitotic cell dynamics in fission yeast under both normal physiological conditions and temperature stress. ResultsAt 25℃, compared with wild-type cells, the SPBC1604.04Δ strain exhibited a pronounced tendency toward mitochondrial fragmentation, accompanied by abnormal mitochondrial content and a significant reduction in mitochondrial fluorescence intensity. These observations suggest impaired mitochondrial homeostasis under normal growth conditions. In addition, the constriction time of actomyosin ring during cytokinesis was markedly prolonged, indicating that deletion of SPBC1604.04 affects the dynamics of the contractile machinery. However, no obvious defects were observed in spindle assembly, spindle elongation, or chromosome segregation. Under heat stress at 37℃, mitochondrial morphology in the SPBC1604.04Δ strain showed a tendency to recover toward a continuous tubular network structure. Mitochondrial content was restored, fluorescence intensity increased, and the constriction time of the actomyosin ring returned to levels comparable to those of wild-type cells. These results indicate that the mitotic defects observed at normal temperature are partially or fully alleviated under heat stress conditions. ConclusionThis study demonstrates that deletion of the SPBC1604.04 gene leads to abnormal mitochondrial content in Schizosaccharomyces pombe. The mitochondrial carrier protein SPBC1604.04 participates in regulating actomyosin ring constriction during mitosis but does not appear to be directly involved in the regulation of spindle dynamics or chromosome segregation. Our findings provide key experimental evidence for understanding the functional link between the SPBC1604.04 gene, mitochondrial homeostasis, and mitotic regulation.

Objective:To investigate the efficacy and safety of bendamustine combined with anti-CD20 monoclonal antibody in the first-line treatment of older patients with indolent B-cell non-Hodgkin lymphoma (B-iNHL) .Methods:The clinical data of 159 patients with B-iNHL enrolled in 16 hospitals from Jiangsu Cooperative Lymphoma Group from December 1, 2019, to April 20, 2024, were analyzed for regimen efficacy and safety. Bendamustine plus rituximab (BR) and bendamustine plus obinutuzumab (BG) were administered to 139 (87.4% ) and 20 (12.6% ) patients, respectively.Results:Among the 159 patients, 101 (63.5% ) were male and 58 (36.5% ) were female, with a median age of 69 years (range: 60–84). Efficacy could be assessed in 138 (86.8% ) patients. The efficacy assessment demonstrated that the overall response rate was 92.0% with complete and partial remissions in 75 (54.3% ) and 52 (37.7% ) cases, respectively. With a median follow-up of 24 months (range: 4–64), the progression-free survival rate was (87.5 ± 3.0) % and the overall survival rate was (83.2 ± 3.3) %. Of the 27 patients who died, 6 (22.2% ) died due to disease progression. The mean applied dose of bendamustine per cycle was 73.0 (50.8–89.7) mg/m 2 per day, administered on days 1 and 2. Adverse events of grade 3 or higher were reported in 53 (33.3% ) patients, with infection (30 cases,18.9% ) and neutropenia (24 cases, 15.1% ) demonstrating the highest incidence. Conclusion:Bendamustine combined with anti-CD20 monoclonal antibody demonstrated good efficacy and is well-tolerated in the first-line treatment of elderly patients with B-iNHL.

Objective:To investigate a new method for rapid detection of the MYOD1 L122R mutation and to analyze the clinical and pathological characteristics of mutation-positive rhabdomyosarcoma.Methods:A MYOD1 mutation detection kit was developed using allele-specific Taqman fluorescence probe technology. A total of 80 rhabdomyosarcoma samples diagnosed at Beijing Children′s Hospital, Capital Medical University from June 2022 to June 2023 were collected for testing. The detection sensitivity, specificity, and consistency rate of the kit were compared with those of the gold standard Sanger sequencing. The demographic, histopathological, and molecular genetic characteristics of patients with MYOD1 mutations were analyzed.Results:Among the 80 rhabdomyosarcoma cases, there were 46 males and 34 females, with an age of onset ranging from 0 to 16 years [mean (6.0±4.4) years], including 32 embryonal rhabdomyosarcoma, 18 alveolar rhabdomyosarcoma, and 30 spindle cell/sclerosing rhabdomyosarcoma. The new kit screened a total of 11 mutations, of which 10 were spindle cell/sclerosing rhabdomyosarcoma and one was embryonal rhabdomyosarcoma. Patients with MYOD1 mutations were typically older (four cases over 10 years old) but could also occur in young children (the youngest being 3-year and 2-month-old). The primary sites were the head and neck region in eight cases, limbs in two cases, and pelvic cavity in one case. Among the six patients with available staging information at initial diagnosis, one was classified as stage 2 and five were stage 3, all of which were intermediate risk. Among the 11 mutation patients, six had recurrence and metastasis, with three deaths; the remaining patients had not shown tumor progression until last follow-up. Compared with the wild type group, the expression level of MYOD1 in mutation patients increased significantly ( χ2=10.66, P=0.01), while the event-free survival rate ( χ2=9.925, P<0.01) and overall survival ( χ2=4.53, P=0.03) rate decreased. Compared with Sanger sequencing, the kit achieved 100% sensitivity and specificity. The kit had a minimum mutation content detection limit of 2% and the reaction could be finished within 2 hours. Additionally, this kit might also be used to detect the expression of MYOD1, thereby aiding the diagnosis of rhabdomyosarcoma. Conclusions:The study has established a new method for accurate and rapid detection of MYOD1 mutation in rhabdomyosarcoma, particularly suitable for the formalin-fixed and paraffin-embedded samples in clinical settings. MYOD1 mutations more likely occur in spindle cell/sclerosing rhabdomyosarcoma of the head and neck region in children. Patients with MYOD1 mutations have an extremely poor prognosis, which is independent of clinical staging and grading. MYOD1 mutation detection in rhabdomyosarcoma has significant value for auxiliary diagnosis and prognostic assessment.

Objective:To explore the incidence, clinical features, genetic variant characteristics and prognosis of Glutaric acidemia type I (GA1) among neonates from Henan Province.Methods:A total of 814 625 neonates undergoing screening for inherited metabolic diseases by tandem mass spectrometry (MS/MS) at the Third Affiliated Hospital of Zhengzhou University from January 2016 to December 2022 were selected as the study subjects. A retrospective method was adopted to collect the clinical data of the patients. Whole exome sequencing was carried out to detect GCDH gene variants in individuals with positive results by GA1 newborn screening, and Sanger sequencing was used to verify the candidate variants. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the pathogenicity of candidate variants was rated. This study was approved by the Medical Ethics Committee of the Hospital (Approval Number: 2019 Medical Ethics Review No. 67). Results:Eight cases of GA1 were diagnosed among the 814 625 neonates. Blood glutaryl carnitine (C5DC) and urine glutaric acid (GA) levels of the 8 children were higher than the normal reference values. In total 12 variants were detected, all of which were missense variants. c. 1064G>A (p.Arg355His) was the most common one, accounting for 21.4% (3/14). Three GCDH gene variants, including 1297G>C (p.Ala433Pro), c. 467G>A (p.Gly156Asp) and c. 1125T>G (p.Cys375Trp), were previously unreported. REVEL software analysis predicted that all of the three variants were harmful. 3D protein structure modeling indicated that the three variants may cause amino acid residue alterations, and c. 1297G>C (p.Ala433Pro) and c. 1125T>G (p.Cys375Trp) may result in increase in hydrogen bonds and may affect the function of GCDH protein. By December 2023, one of the eight children had deceased, and another child had severe clinical symptoms with poor prognosis. Six children had a good prognosis, of which two had mild motor development delay and four had normal development without clinical symptoms. Conclusion:The incidence of GA1 in newborns screened by MS/MS in Henan Province is 1/101 828, and the carrier rate of pathogenic GCDH variants is 1/160. The c. 1064G>A (p.Arg355His) may be the hotspot variant of the GCDH gene among children with GA1 in Henan. Discovery of the three novel variants has enriched the mutational spectrum of the GCDH gene and provide a basis for the early diagnosis, treatment, prognosis and genetic counseling of this disease.

Objective:To explore the impact of age on the genetic variant spectrum and prognosis of patients with previously untreated Diffuse large B-cell lymphoma (DLBCL).Methods:A retrospective analysis was conducted on the clinical data and follow-up information of 254 previously untreated DLBCL patients from 14 hospitals in the Jiangsu Cooperative Lymphoma Group (JCLG) enrolled from July 2018 and July 2023. Following extraction of DNA from tumor tissue samples, next-generation sequencing (NGS) technique was employed to analyze the genetic variant spectrum of the DLBCL patients, with an evaluation of the relationship between age and genetic variants as well as prognosis. This study was approved by the Medical Ethics Committee of the Affiliated Hospital of Nantong University (Ethics No.: 2023-K048-01).Results:The median age of the 254 DLBCL patients was 62 years old, with 55% of patients aged 60 years or above. Clinical evaluation showed that younger (< 60 years) patients had higher complete response (CR) (70% vs. 59%), and objective response rate (ORR) (88% vs. 79%) than older patients, though the difference between the two groups was not statistically. Survival analysis indicated that both the five-year overall survival (OS) (82.7% vs. 71.7%, P=0.006) and progression-free survival (PFS) (70.6% vs. 50.2%, P<0.05) rates were significantly higher in younger patients. NGS showed that 99.6% of the patients harbored genetic variants, with PIM1, KMT2D, TP53, MYD88, and CD79B being the most common genes. Age significantly affected the variant frequency of certain genes, with MYC variants serving an adverse prognostic factor for OS in younger patients ( P=0.001), while TP53 ( P=0.024) and BCL2 ( P=0.002) variants significantly impacted OS in older patients. Prognostic analysis identified age ≥ 60 years ( HR=3.439, 95% CI=1.318~9.874), presence of B symptoms ( HR = 2.871, 95% CI=1.133~7.307), and elevated lactate dehydrogenase ( HR=3.528, 95% CI=1.231~10.66) as independent adverse prognostic factors. Conclusion:Age, genetic variants, and clinical factors may significantly affect the prognosis of the DLBCL patients. Younger patients have better survival compared to older patients. Variants of the MYC, BCL2, and TP53 genes are closely associated with poor prognosis.

Objective:To summarize the clinical characteristics of elderly patients with stage Ⅰ diffuse large B-cell lymphoma (DLBCL) and analyze the factors associated with prognosis.Methods:A case series study was conducted by retrospectively collecting clinical data from patients aged over 60 years with newly diagnosed stage Ⅰ DLBCL across 20 medical centers in Jiangsu Province, China, between June 2010 and April 2023. The involved site, classification and treatment plan were summarized. The primary endpoints were progression-free survival (PFS) and overall survival (OS). Statistical analyses were performed using the Kaplan-Meier method, and Cox regression model.Results:The study included 255 patients with a median age of 69 years, of whom 130 (51.0%) were male, 66 (25.9%) were aged ≥75 years and 26 (10.1%) had a high Charlson Comorbidity Index (CCI) score of ≥2. Extranodal involvement was observed in 163 (63.9%) patients, with the stomach (37.4%, 61/163), intestine (19.0%, 31/163), testes (11.0%, 18/163), and breast (7.4%, 12/163) being the most frequently affected sites. The non-germinal center B-cell (non-GCB) subtype was prevalent in 63.7% of patients (142/223), with no significant difference between the nodal and extranodal groups ( P=0.681). Furthermore, 73.9% (184/249) and 11.7% (29/249) of patients received the R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) and R-miniCHOP regimen, respectively. The overall 3-year PFS rate was 81.5%, and the 3-year OS rate was 85.6%. Patients aged ≥75 years ( HR=2.910, 95% CI 1.565-5.408, P=0.001) and/or with a CCI score ≥2 ( HR=2.324, 95% CI 1.141-4.732, P=0.020) had a significantly poorer PFS. Incorporating age ≥75 years and CCI score ≥2 into the stage-modified international prognostic index (sm-IPI) can better stratify the prognosis of elderly patients with stage Ⅰ DLBCL. The 3-year PFS rate was 48.7% in the high-risk group versus 85.7% in the low-risk group ( P<0.001). Conclusions:Our findings show that the elderly patients with stage Ⅰ DLBCL were predominantly characterized by extranodal involvement (particularly in the stomach and intestinal tract) and non-GCB subtype. Age ≥75 years and CCI ≥2 were identified as independent prognostic factors. The newly established sm-IPI-75-CCI incorporating these factors demonstrated superior prognostic discrimination compared to conventional risk assessment systems.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

OBJECTIVE: To explore the incidence, clinical features, genetic variant characteristics and prognosis of Glutaric acidemia type I (GA1) among neonates from Henan Province. METHODS: A total of 814 625 neonates undergoing screening for inherited metabolic diseases by tandem mass spectrometry (MS/MS) at the Third Affiliated Hospital of Zhengzhou University from January 2016 to December 2022 were selected as the study subjects. A retrospective method was adopted to collect the clinical data of the patients. Whole exome sequencing was carried out to detect GCDH gene variants in individuals with positive results by GA1 newborn screening, and Sanger sequencing was used to verify the candidate variants. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the pathogenicity of candidate variants was rated. This study was approved by the Medical Ethics Committee of the Hospital (Ethics Number: 2019 Medical Ethics Review No. 67). RESULTS: Eight cases of GA1 were diagnosed among the 814 625 neonates. Blood glutaryl carnitine (C5DC) and urine glutaric acid (GA) levels of the 8 children were higher than the normal reference values. In total 12 variants were detected, all of which were missense variants. c.1064G>A (p.Arg355His) was the most common one, accounting for 21.4% (3/14). Three GCDH gene variants, including 1297G>C (p.Ala433Pro), c.467G>A (p.Gly156Asp) and c.1125T>G (p.Cys375Trp), were previously unreported. REVEL software analysis predicted that all of the three variants were harmful. 3D protein structure modeling indicated that the three variants may cause amino acid residue alterations, and c.1297G>C (p.Ala433Pro) and c.1125T>G (p.Cys375Trp) may result in increase in hydrogen bonds and affect the function of GCDH protein. By December 2023, one of the eight children had deceased, and another child had severe clinical symptoms with poor prognosis. Six children had a good prognosis, of which two had mild motor development delay and four had normal development without clinical symptoms. CONCLUSION The incidence of GA1 in newborns screened by MS/MS in Henan Province is 1/101 828, and the carrier rate of pathogenic GCDH variants is 1/160. The c.1064G>A (p.Arg355His) may be the hotspot variant of the GCDH gene among children with GA1 in Henan. Discovery of the three novel variants has enriched the mutational spectrum of the GCDH gene and provide a basis for the early diagnosis, treatment, prognosis and genetic counseling of this disease.
Humans ; Amino Acid Metabolism, Inborn Errors/epidemiology* ; Glutaryl-CoA Dehydrogenase/chemistry* ; Infant, Newborn ; Female ; Neonatal Screening/methods* ; Male ; Brain Diseases, Metabolic/epidemiology* ; China/epidemiology* ; Retrospective Studies ; Mutation ; Genetic Variation ; Glutarates