中南大学学报(医学版)最新文献

Objectives: Flotillin-2 (FLOT2) is a prototypical oncogenic and a potential target for cancer therapy. However, strategies for targeting FLOT2 remain undefined. Post-translational modifications are crucial for regulating protein stability, function, and localization. Understanding the mechanisms and roles of post-translational modifications is key to developing targeted therapies. This study aims to investigate the regulation and function of lysine acetylation of FLOT2 in nasopharyngeal carcinoma, providing new insights for targeting FLOT2 in cancer intervention.

Methods: The PhosphoSitePlus database was used to analyze the lysine acetylation sites of FLOT2, and a lysine acetylation site mutation of FLOT2 [FLOT2 (K211R)] was constructed. Nasopharyngeal carcinoma cells were treated with histone deacetylase (HDAC) inhibitor trichostatin A (TSA) and Sirt family deacetylase inhibitor nicotinamide (NAM). TSA-treated human embryonic kidney (HEK)-293T were transfected with FLOT2 mutant plasmids. Co-immunoprecipitation (Co-IP) was used to detect total acetylation levels of FLOT2 and the effects of specific lysine (K) site mutations on FLOT2 acetylation. Western blotting was used to detect FLOT2/FLAG-FLOT2 protein expression in TSA-treated nasopharyngeal carcinoma cells transfected with FLOT mutant plasmids, and real-time reverse transcription PCR (real-time RT-PCR) was used to detect FLOT2 mRNA expression. Nasopharyngeal carcinoma cells were treated with TSA combined with MG132 or chloroquine (CQ) to analyze FLOT2 protein expression. Cycloheximide (CHX) was used to treat HEK-293T cells transfected with FLAG-FLOT2 (WT) or FLAG-FLOT2(K211R) plasmids to assess protein degradation rates. The BioGrid database was used to identify potential interactions between FLOT2 and HDAC6, which were validated by Co-IP. HEK-293T cells were co-transfected with FLAG-FLOT2 (WT)/FLAG-FLOT2 (K211R) and Vector/HDAC6 plasmids, and grouped into FLAG-FLOT2 (WT)+Vector, FLAG-FLOT2 (WT)+HDAC6, FLAG-FLOT2 (K211R)+Vector, and FLAG-FLOT2 (K211R)+HDAC6 to analyze the impact of K211R mutation on total lysine acetylation levels. In 6-0B cells, overexpression of FLOT2 (WT) and FLOT2 (K211R) was performed, and the biological functions of FLOT2 acetylation site mutants were assessed using cell counting kit-8 (CCK-8), colony formation, and Transwell invasion assays.

Results: The PhosphoSitePlus database indicated that FLOT2 has an acetylation modification at the K211 site. Co-IP confirmed significant acetylation of FLOT2, with TSA significantly increasing overall FLOT2 acetylation levels, while NAM had no effect. Mutation at the K211 site significantly reduced overall FLOT2 acetylation, unaffected by TSA. TSA decreased FLOT2 protein expression in nasopharyngeal carcinoma cells without affecting FLOT2 mRNA levels or FLOT2 (K211R) protein expression in transfected cells. The degradation rate of FLOT2 (K211R) protein

Objectives: The emergence of polymyxin-resistant Klebsiella pneumoniae (KPN) in clinical settings necessitates an analysis of its antibiotic resistance characteristics, epidemiological features, and risk factors for its development. This study aims to provide insights for the prevention and control of polymyxin-resistant KPN infections.

Methods: Thirty clinical isolates of polymyxin-resistant KPN were collected from the Third Xiangya Hospital of Central South University. Their antibiotic resistance profiles were analyzed. The presence of carbapenemase KPC, OXA-48, VIM, IMP, and NDM was detected using colloidal gold immunochromatography. Hypervirulent KPN was initially screened using the string test. Biofilm formation capacity was assessed using crystal violet staining. Combination drug susceptibility tests (polymyxin B with meropenem, tigecycline, cefoperazone/sulbactam) were conducted using the checkerboard method. Polymyxin-related resistance genes were detected by PCR. Multi-locus sequence typing (MLST) was performed for genotyping and phylogenetic tree construction. The study also involved collecting data from carbapenem-resistant (CR)-KPN polymyxin-resistant strains (23 strains, experimental group) and CR-KPN polymyxin-sensitive strains (57 strains, control group) to analyze potential risk factors for polymyxin-resistant KPN infection through univariate analysis and multivariate Logistic regression. The induction of resistance by continuous exposure to polymyxin B and colistin E was also tested.

Results: Among the 30 polymyxin-resistant KPN isolates, 28 were CR-KPN, all producing KPC enzyme. Four isolates were positive in the string test. Most isolates showed strong biofilm formation capabilities. Combination therapy showed additive or synergistic effects. All isolates carried the pmrA and phoP genes, while no mcr-1 or mcr-2 genes were detected. MLST results indicated that ST11 was the predominant type. The phylogenetic tree suggested that polymyxin-resistant KPN had not caused a hospital outbreak in the institution. The use of two or more different classes of antibiotics and the use of polymyxin were identified as independent risk factors for the development of polymyxin-resistant strains. Continuous use of polymyxin induced drug resistance.

Conclusions: Polymyxin-resistant KPN is resistant to nearly all commonly used antibiotics, making polymyxin-based combination therapy a viable option. No plasmid-mediated polymyxin-resistant KPN has been isolated in the hospital. Polymyxin can induce resistance in KPN, highlighting the need for rational antibiotic use in clinical settings to delay the emergence of resistance.

Objectives: Non-alcoholic fatty liver disease (NAFLD) has significant genetic susceptibility. Adipocytokines play a crucial role in NAFLD development by participating in insulin resistance and hepatic steatosis. However, the association between adipocytokine pathway genes and NAFLD remains unclear. This study aims to explore the association of gene polymorphisms in the adipocytokine pathway and their interactions with NAFLD in obese children.

Methods: A case-control study was conducted, dividing obese children into NAFLD and control groups. Peripheral venous blood (2 mL) was collected from each participant for DNA extraction. A total of 14 single nucleotide polymorphisms (SNP) in the adipocytokine pathway were genotyped using multiplex PCR and high-throughput sequencing. Univariate and multivariate Logistic regression analyses were used to assess the association between SNP and NAFLD in obese children. Dominant models were used to analyze additive and multiplicative interactions via crossover analysis and Logistic regression. Generalized multifactor dimensionality reduction (GMDR) was used to detect gene-gene interactions among the 14 SNPs and their association with NAFLD in obese children.

Results: A total of 1 022 children were included, with 511 in the NAFLD group and 511 in the control group. After adjusting for age, gender, and BMI, multivariate Logistic regression showed that PPARG rs1801282 was associated with NAFLD in the obese children in 3 genetic models: heterozygote model (CG vs CC, OR=0.58, 95% CI 0.36 to 0.95, P=0.029), dominant model (GG+CG vs CC, OR=0.62, 95% CI 0.38 to 1.00, P=0.049), and overdominant model (CC+GG vs CG, OR=1.72, 95% CI 1.06 to 2.80, P=0.028). PRKAG2 rs12703159 was associated with NAFLD in 4 genetic models: heterozygous model (CT vs CC, OR=1.51, 95% CI 1.10 to 2.07, P=0.011), dominant model (CT+TT vs CC, OR=1.50, 95% CI 1.10 to 2.03, P=0.010), overdominant model (CC+TT vs CT, OR=0.67, 95% CI 0.49 to 0.92, P=0.012), and additive model (CC vs CT vs TT, OR=1.40, 95% CI 1.07 to 1.83, P=0.015). No significant multiplicative or additive interaction between PPARG rs1801282 and PRKAG2 rs12703159 was found in association with NAFLD. GMDR analysis, adjusted for age, gender, and BMI, revealed no statistically significant interactions among the 14 SNPs (all P>0.05).

Conclusions: Mutations in PPARG rs1801282 and PRKAG2 rs12703159 are associated with NAFLD in obese children. However, no gene-gene interactions among the SNP are found to be associated with NAFLD in obese children.

Objectives: Radiotherapy is the primary treatment for nasopharyngeal carcinoma, but it frequently leads to radiotherapy-induced temporal lobe injury (RTLI). Magnetic resonance imaging (MRI) is the main diagnostic method for RTLI after radiotherapy for nasopharyngeal carcinoma, but it is prone to missed diagnoses. This study aims to investigate the causes of missed diagnoses of RTLI in nasopharyngeal carcinoma patients undergoing MRI after radiotherapy.

Methods: Clinical and MRI data from nasopharyngeal carcinoma patients diagnosed and treated with radiotherapy at Xiangya Hospital of Central South University, from January 2010 to April 2021, were collected. Two radiologists reviewed all head and neck MRIs (including nasopharyngeal and brain MRIs) before and after radiotherapy of identify cases of late delayed response-type RTLI for the first time. If the original diagnosis of the initial RTLI in nasopharyngeal carcinoma patients did not report temporal lobe lesions, it was defined as a missed diagnosis. The first diagnosis of RTLI cases was divided into a missed diagnosis group and a non-missed diagnosis group. Clinical and imaging data were compared between the 2 groups, and multivariate logistic regression analysis was used to identify independent risk factors for MRI missed diagnoses of initial RTLI.

Results: A total of 187 nasopharyngeal carcinoma with post-radiotherapy RTLI were included. The original diagnostic reports missed 120 cases and accurately diagnosed 67 cases, with an initial RTLI diagnosis accuracy rate of 35.8% and a missed diagnosis rate of 64.2%. There were statistically significant differences between the missed diagnosis group and the non-missed diagnosis group in terms of lesion size, location, presence of contralateral temporal lobe lesions, white matter high signal, cystic degeneration, hemorrhage, fluid attenuated inversion recovery (FLAIR), and examination site (all P<0.05). Multivariate logistic regression analysis showed that lesions ≤25 mm, non-enhancing lesions, lesions without cystic degeneration or hemorrhage, lesions located only in the medial temporal lobe, and MRI examination only of the nasopharynx were independent risk factors for missed MRI diagnosis of initial RTLI (all P<0.05).

Conclusions: The missed diagnosis of initial RTLI on MRI is mainly related to lesion size and location, imaging characteristics, and MRI examination site.

Objectives: Bacterial liver abscess is one of the common infectious diseases of the digestive system. Invasive Klebsiella pneumoniae liver abscess syndrome (IKLAS) refers to cases where, in addition to liver abscess, there are migratory infections foci or other invasive manifestations. The clinical characteristics and risk factors of IKLAS are not fully elucidated, and there is a lack of research on the effectiveness and cost-effectiveness of different treatment methods. This study aims to compare the clinical characteristics of patients with IKLAS and non-IKLAS, and explore effective and economical treatment methods.

Methods: This retrospective study collected medical records of patients with Klebsiella pneumoniae liver abscess treated at Xiangya Hospital of Central South University from January 2010 to December 2023. A total of 201 patients were included, dividing into an IKLAS group (n=37) and a non-IKLAS group (n=164). Differences in demographics, symptoms and signs, laboratory indicators, imaging characteristics, comorbidities, treatment methods, treatment outcomes, and direct treatment costs between 2 groups were analyzed. The study also compared the effectiveness and costs of different treatment methods.

Results: Compared with the non-IKLAS group, the proportion of patients with diabetes, Quick Sequential Organ Failure Assessment (qSOFA)≥2, immune deficiency, anemia, and thrombocytopenia in the IKLAS group was higher, and the level of procalcitonin at the onset in the IKLAS group was also higher (all P<0.05). In terms of symptoms and signs, the IKLAS group had a higher proportion of visual abnormalities and a lower proportion of complaints of abdominal pain (both P<0.05). In terms of complications, the incidence of combined pleural effusion, pulmonary infection, acute renal failure, respiratory failure, and multiple organ failure was higher in the IKLAS group (all P<0.05). The IKLAS group had a higher proportion of patients treated with antibiotics alone (24.32% vs 11.59%), while the non-IKLAS group had a higher proportion of patients treated with antibiotics combined with puncture and drainage (86.59% vs 64.86%, both P<0.05). The overall effective rate of the IKLAS group (83.78%) was lower than that of the non-IKLAS group (95.73%), and the treatment and drug costs were higher (all P<0.05). The treatment method of antibiotics combined with surgical resection of infectious foci showed a 100% improvement rate, antibiotics combined with abscess puncture and drainage had an 84.9% improvement rate, and in antibiotics alone had an 82.1% improvement rate, with statistical differences among the 3 treatment methods (P<0.05). In terms of treatment costs, antibiotics alone were the most expensive (P<0.05).

Conclusions: Patients with IKLAS have poorer prognosis and higher direct medical c

Objectives: The drug-resistant genes carried by carbapenem-resistant Klebsiella pneumoniae (CRKP) limit clinical treatment options, and its virulence genes severely affect patient prognosis. This study aims to investigate the distribution of virulence genes, capsular serotypes, and molecular epidemiological characteristics of CRKP in ICU, to understand the characteristics of CRKP infections in ICU, and to provide a scientific basis for effective monitoring and control of CRKP infections in ICU.

Methods: A total of 40 non-duplicate strains of CRKP isolated from the ICU of Guangdong Provincial People's Hospital between January 2021 and December 2022 were collected and analyzed. Whole-genome sequencing was used to analyze the distribution of resistance genes, virulence genes, and capsular serotypes of the strains. The sequences of 7 housekeeping genes of CRKP genome were uploaded to the Klebsiella pneumoniae (KPN)multilocus sequence typing (MLST) database to determine the sequence types (STs) of the strains.

Results: The age of the 40 ICU CRKP-infected patients was (69.03±17.82) years old, with various underlying diseases, and there were 20 patients with improved clinical outcome and 20 patients with death. The isolated strains primarily originated from mid-stream urine and bronchoalveolar lavage fluid. Whole-genome sequencing results revealed that the strains predominantly carried bla_KPC-1 (29 strains, 72.5%) and bla_NDM-1 (6 strains, 15.0%), with 5 strains carrying both bla_KPC-1 and bla_NDM-1. Various virulence genes were detected, among which the carriage rates of genes such as entA, entB, entE, entS, fepA, fepC, fepG, yag/ecp, and ompA reached 100%, while the carriage rates of genes such as entD, fimB, iroB, iroD, fes,and pla were low. The CRKP strains isolated from ICU were predominantly ST11 (27 cases, 67.5%), with KL64 being the main capsular serotype (29 cases, 72.5%). A total of 23 ST11-KL64 CRKP strains were detected, accounting for 57.5%.

Conclusions: The main type of ICU CRKP is ST11-KL64, carrying various virulence genes, primarily those related to iron absorption. Furthermore, bla_KPC has shifted from bla_KPC-2 to bla_KPC-1. Therefore, close monitoring of the molecular epidemiological changes of CRKP is necessary, and strict control measures should be implemented to effectively curb the occurrence of CRKP infections.

Objectives: Age-related cataract is the most common type of adult cataract and a leading cause of blindness. Currently, there are few reports on the establishment of animal models for age-related cataract. During the experimental breeding of Microtus fortis (M. fortis), we first observed that M. fortis aged 12 to 15 months could naturally develop cataracts. This study aims to explore the possibility of developing them as an animal model for age-related cataract via identifing and analyzing spontaneous cataract in M. fortis.

Methods: The 12-month-old healthy M. fortis were served as a control group and 12-month-old cataractous M. fortis were served as an experimental group. The lens transparency was observed using the slit-lamp biomicroscope. Hematoxylin and eosin staining was used to detect pathological changes in the lens. Biochemical detection methods were applied to detect blood routine, blood glucose levels, the serum activities of superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in both groups. Finally, real-time RT-PCR was used to detect the transcription levels of cataract-related genes in the lens of 2 groups.

Results: Compared with the control group, the lens of cataract M. fortis showed severely visible opacity, the structure of lens was destroyed seriously, and some pathological damage, such as swelling, degeneration/necrosis, calcification, hyperplasia, and fiber liquefaction were found in lens epithelial cells (LECs). The fibrous structure was disorganized and irregularly distributed with morgagnian globules (MGs) aggregated in the degenerated lens fibers. There was no statistically significant difference in blood glucose levels between the experimental and control groups (P>0.05). However, white blood cell (WBC) count (P<0.05), lymphocyte count (P<0.01), and lymphocyte ratio (P<0.05) were significantly decreased, while neutrophil percentage (P<0.05) and monocyte ratio (P<0.01) were significantly increased. The serum activities of SOD and GSH-Px (both P<0.05) were both reduced. The mRNAs of cataract-related genes, including CRYAA, CRYBA1, CRYBB3, Bsfp1, GJA3, CRYBA2, MIP, HspB1, DNase2B, and GJA8, were significantly downregultaed in the lenses of the experimental group (all P<0.05).

Conclusions: There are significant differences in lens pathological changes, peroxidase levels, and cataract-related gene expression between cataract and healthy M. fortis. The developed cataract spontaneously in M. fortis is closely related to age, the cataract M. fortis might be an ideal animal model for the research of age-related cataract.

Amyloidosis is a rare disease. This paper reports a case of localized secondary hypopharyngeal amyloidosis presenting with pulmonary tuberculosis as the initial symptom. The patient lacked specific clinical manifestations and primarily exhibited symptoms such as cough, sputum production, acid reflux, belching, and abdominal pain. Chest CT indicated bronchiectasis with infection and pulmonary tuberculosis. Digestive endoscopy revealed a white mucosal elevation at the right pyriform sinus of the hypopharynx. Pathological diagnosis confirmed amyloid deposits in the hypopharyngeal mucosal tissue. The patient tested positive for anti-amyloid A antibodies, Congo red staining (+), and periodate Schiff staining (+). Amyloidosis commonly affects the digestive system and may have various etiologies, often presenting with symptoms that overlap with other digestive system diseases, leading to frequent misdiagnosis and missed optimal treatment opportunities. The hypopharynx, a highly folded and narrow chamber that serves as a common passage for the digestive and respiratory tracts, can be effectively evaluated for amyloidosis using digestive endoscopy.

The prevention and control requirements for HIV/AIDS vary significantly among different populations, posing substantial challenges to the formulation and implementation of intervention strategies. Dynamically assessing the heterogeneity and disease progression trajectories of various groups is crucial. Latent class growth model (LCGM) serves as a statistical approach that fits a longitudinal data into N subgroups of individual development trajectories, identifying and analyzing the progression paths of different subgroups, thereby offering a novel perspective for disease control strategies. LCGM has shown significant advantages in the application of HIV/AIDS prevention and control, especially in gaining a deeper understanding and analysis of epidemiological characteristics, risk behaviors, psychological research, heterogeneity in testing, and dynamic changes. Summarizing the advantages and limitations of applying LCGM can provide a reliable basis for precise prevention and control of HIV/AIDS.

Objectives: Interruption of aortic arch (IAA) is a rare congenital heart disease. This study aims to investigate echocardiographic features and pathological ultrastructural characteristics of fetal IAA and to further analyze its pathological evolution.

Methods: A retrospective analysis was conducted on prenatal echocardiographic, post-surgical, or autopsy findings of fetuses prenatally diagnosed with IAA. Prenatal echocardiographic tracking was used to observe the internal diameters and Z-scores of different segments of the aortic arch and the changes in the narrowed section. These observations were combined with autopsy and pathological findings to explore the potential intrauterine evolution of IAA and its cytological basis.

Results: The study included 34 fetuses with IAA, with 3, 3, and 28 fetuses prenatally diagnosed with aortic arch dysplasia (AAD), coarctation of aorta (CoA), and IAA, respectively. The 3 AAD and 3 CoA fetuses chose termination of pregnancy 1 to 2 weeks after prenatal ultrasound diagnosis, and autopsy confirmed IAA. Among the 28 fetuses prenatally diagnosed with IAA, 6 cases of CoA progressively worsened, eventually evolving into type A IAA as observed through echocardiographic follow-up. The remaining 22 cases were diagnosed as IAA on the first prenatal ultrasound. Postnatal surgery corrected 3 cases, while 27 cases opted for pregnancy termination, and 4 cases resulted in intrauterine death. Echocardiographic features of the fetal IAA included a significantly smaller left ventricle compared with the right or negligible difference on the four-chamber view, a significantly smaller aorta than the pulmonary artery on the three-vessel view, and a lack of connection between the aorta and the descending aorta on the three-vessel-trachea and aortic arch views. The aortic arch appears less curved and more rigid, losing the normal "V" shape between the aorta, ductus arteriosus, and descending aorta. Color Doppler ultrasound showed no continuous blood flow signal at the interruption site, with reversed blood flow visible in the ductus arteriosus. Transmission electron microscopy of 7 IAA fetuses revealed numerous disorganized smooth muscle cells between the elastic membranes near the aortic arch interruption site, significantly increased in number compared with the proximal ascending aorta. The elastic membranes were thicker and more twisted near the interruption site. The interruption area lacked normal endothelial cells and lumen, with only remnants of necrotic endothelial cells, disorganized short and thick elastic membranes, and randomly arranged smooth muscle cells.

Conclusions: Prenatal echocardiography is the primary diagnostic tool for fetal IAA. Post-surgical follow-up and autopsy help identify complications and disease characteristics, enhancing diagnostic accuracy. Some fetal IAA may evolve from AAD or CoA, with potential pathogenesis r