Post-COVID-19 Pandemic Rebound of Macrolide-Resistant Mycoplasma pneumoniae Infection: A Descriptive Study.

The rebound characteristics of respiratory infections after lifting pandemic control measures were uncertain. From January to November 2023, patients presenting at a teaching hospital were tested for common respiratory viruses and Mycoplasma pneumoniae using a combination of antigen, nucleic acid amplification, and targeted next-generation sequencing (tNGS) tests. The number and rate of positive tests per month, clinical and microbiological characteristics were analyzed. A rapid rebound of SARS-CoV-2 was followed by a slower rebound of M. pneumoniae, with an interval of 5 months between their peaks. The hospitalization rate was higher, with infections caused by respiratory viruses compared to M. pneumoniae. Though the pediatric hospitalization rate of respiratory viruses (66.1%) was higher than that of M. pneumoniae (34.0%), the 4094 cases of M. pneumoniae within 6 months posed a huge burden on healthcare services. Multivariate analysis revealed that M. pneumoniae-infected adults had more fatigue, comorbidities, and higher serum C-reactive protein, whereas children had a higher incidence of other respiratory pathogens detected by tNGS or pathogen-specific PCR, fever, and were more likely to be female. A total of 85% of M. pneumoniae-positive specimens had mutations detected at the 23rRNA gene, with 99.7% showing A2063G mutation. Days to defervescence were longer in those not treated by effective antibiotics and those requiring a change in antibiotic treatment. A delayed but significant rebound of M. pneumoniae was observed after the complete relaxation of pandemic control measures. No unusual, unexplained, or unresponsive cases of respiratory infections which warrant further investigation were identified.

[Investigation of Antigen and Gene Frequency of Kell(K) and Rh(D) Blood Groups in Xinjiang].

OBJECTIVE: To investigate the phenotypes and gene frequencies of Kell blood group system K antigen and Rh blood group system D antigen in Xinjiang, and summarize and understand the distribution of Kell(K) blood type and Rh(D) blood type in this area. METHODS: A total of 12 840 patients who met the inclusion criteria during physical examination and treatment in our hospital and 18 medical institutions in our district from January 1, 2019 to December 31, 2019 were collected for identification of Kell blood group system K antigen and Rh blood group System D antigen, and the distribution of K and D blood groups in different regions, genders and nationalities were investigated and statistically analyzed. RESULTS: The proportion of K positive in the samples was 1.39%, the highest was 1.91% in southern Xinjiang, and the lowest was 1.03% in northern Xinjiang(P<0.01). The proportion of Rh(D) negative samples was 2.75% and the gene frequency was 16.64%. The proportion of Rh(D) negative samples was 4.03% and the gene frequency was 20.10% in southern Xinjiang, followed by eastern Xinjiang and the lowest in northern Xinjiang (P<0.01). The frequency of K antigen in Uygur nationality was the highest, reaching 2.16%, Kirgiz 1.54%, and the distribution trend of D/d antigen was similar to that of K antigen. Among women, the K positive frequency of Kazak nationality was slightly higher than that of Mongolian nationality. The highest proportion of K positive in Uygur women was 2.38%, which was higher than that in Uygur men (1.86%). The frequency of d phenotype in Kazak women was 3.15%, which was higher than that in Kirgiz （2.89%） (P<0.01). CONCLUSION: The distributions of Kell(K) and Rh(D) blood groups in northern and southern Xinjiang and eastern Xinjiang had its own unique characteristics and differences. There are significant differences in blood group distribution among different ethnic groups and gender groups. In the future, k antigen detection can be included to further improve the investigation on the distribution of Kell blood group system in this region.

miR-124 delivered by BM-MSCs-derived exosomes targets MCT1 of tumor-infiltrating Treg cells and improves ovarian cancer immunotherapy.

Metabolic rewiring of tumor cells leads to an enrichment of lactate in the tumor microenvironment (TME). This lactate-rich environment of solid tumors has been reported to support tumor-infiltrating regulatory T (Treg) cells. Therefore, agents that modify the lactate metabolism of Treg cells have therapeutic potential. Monocarboxylate transporter 1 (MCT1), which Treg cells predominantly express, plays an essential role in the metabolism of tumor-infiltrating Treg cells. In this study, we show that miR-124 directly targets MCT1 and reduces lactate uptake, eventually impairing the immune-suppressive capacity of Treg cells. Particularly, exosomal miR-124 derived from bone marrow mesenchymal stromal cells (BM-MSCs) slows tumor growth and increases response to PD-1 blockade therapy. These data indicate a potential treatment strategy for improving immune checkpoint blockade therapy using miR-124-carried BM-MSCs-derived exosomes.

Resveratrol reduces lactate production and modifies the ovarian cancer immune microenvironment.

Tumor cells show deregulated metabolism leading to an enrichment of lactate in the tumor microenvironment (TME). This lactate-rich environment has been reported to impair effector T cells. However, T-regulatory cells (Tregs) show metabolic advantages in lactate-rich TME that maintain a strong suppression of effector T cells, which leads to tumor immune evasion. Therefore, the glycolytic process of tumors could represent a therapeutic target, and agents that modify the energy metabolism of tumor cells have therapeutic potential. Resveratrol is a naturally occurring polyphenol that has been confirmed to suppress tumor cells' glycolytic metabolism. In this study, we show that resveratrol induces metabolic reprogramming in ovarian cancer cells. Resveratrol increases oxidative and decreases glycolysis, in association with decreased lactate production both in vitro and in vivo. Lactate reduction in TME weakens the suppressive function of Tregs, and subsequently restores anti-tumor immunity. Significantly, combined resveratrol and PD-1 blockade promote anti-tumor efficacy. These data suggest that resveratrol's anti-tumor actions in ovarian cancer could be explained, in part, through modification of the anti-tumor immunity, and indicate a novel treatment strategy for improving immune checkpoint blockade therapy using resveratrol.

Metformin prevents PFKFB3-related aerobic glycolysis from enhancing collagen synthesis in lung fibroblasts by regulating AMPK/mTOR pathway.

Aerobic glycolysis has been shown to contribute to the abnormal activation of lung fibroblasts with excessive collagen deposition in lipopolysaccharide (LPS)-induced pulmonary fibrosis. Targeting aerobic glycolysis in lung fibroblasts might therefore be considered as a promising therapeutic approach for LPS-induced pulmonary fibrosis. In the present study, the aim was to investigate whether metformin, a widely used agent for treating type 2 diabetes, could alleviate LPS-induced lung fibroblast collagen synthesis and its potential underlying mechanisms. Different concentrations of metformin were used to treat the human lung fibroblast MRC-5 cells after LPS challenge. Indicators of aerobic glycolysis in MRC-5 cells were detected by measuring glucose consumption and lactate levels in culture medium in addition to lactate dehydrogenase activity in cellular lysates. The glucose consumption, lactate levels and the lactate dehydrogenase activity were measured respectively using colorimetric/fluorometric and ELISA kits. The effects of metformin in AMP-activated protein kinase (AMPK) activation was assessed by mitochondrial complex I activity kits. Collagen I, α-smooth muscle actin (α-SMA) and collagen III were used as markers of collagen synthesis, which was measured using western blotting, whereas phosphorylated (p-) AMPK, AMPK, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) and mTOR were detected by western blotting. Metformin significantly decreased mitochondrial complex I activity and upregulated the expression of p-AMPK/AMPK protein in a concentration-dependent manner. Furthermore, the aerobic glycolysis mediated by PFKFB3 and collagen synthesis in LPS-treated MRC-5 cells was gradually inhibited with increasing concentrations of metformin. However, this inhibitory role of metformin on PFKFB3-meditaed aerobic glycolysis and collagen synthesis was prevented by treatments with 3BDO and compound C, which are specific mTOR activator and AMPK inhibitor, respectively. Taken together, the findings from this study suggested that metformin may prevent PFKFB3-associated aerobic glycolysis from enhancing collagen synthesis in lung fibroblasts via regulating the AMPK/mTOR pathway.

[Efficacy of Oral Cyclophosphamide for Treatment of Refractory T-cell Large Granular Lymphocytic Leukemia Accompanied with Pure Erythrocyte Aplastic Anemia].

OBJECTIVE: To explore the clinical effects of oral small dose of cyclophosphamide (CTX) in the treatment of T-cell large granular lymphocytic leukemia (T-LGLL) accompanied with pure red cell aplasia (PRCA). METHODS: The clinical features, characteristics of laboratory examinations and the process of oral small dose of CTX treatment after the ineffective treatment of cyclosporine A combining with prednisone in 1 case of T-LGLL with PRCA were reported and discussed with related references. RESULTS: The elderly female patient had indolent process, mainly presenting with anemia and significant low hyperplasia of bone marrow erythrocyte cells. Peripheral blood smear showed mainly with characteristic large granular lymphocytic morphology. The results of immunophenotypic analyses and genetic reassortment were compatible with T-LGLL. No effects were shown after 5 months of cyclosporine A combining with prednisone treatment and the patient still needed recurrent blood transfusion. CTX was prescribed as a second-line medication and the dose was 100 mg/d. Hemoglobin could returned to normal level and the efficacy remained for 1 year even after the medication was stopped. CONCLUSION: T-LGLL accompanied with PRCA is a rare disease and oral small dose CTX can be an effective therapeutic regimen.

High index of suspicion for brucellosis in a highly cosmopolitan city in southern China.

BACKGROUND: Brucellosis is one of the most widespread zoonosis in the world. In China, 90% of human brucellosis occurs in six northern agricultural provinces. However, there is a recent increase in the trend of human brucellosis in southern provinces with limited cases reported in the literature. Our study aims to describe the clinical features and epidemiology of brucellosis in a tertiary hospital in southern China. METHODS: A retrospective case series of brucellosis was conducted between January 1, 2014 and October 31. 2018. Cases were identified based on positive Brucella serology by tube agglutination test, or positive culture from clinical specimen identified by Vitek 2 and MALDL-TOF MS. Clinical details of brucellosis including patients' occupation, risk factors, and complications were analyzed. Clinical characteristics between patients from Guangdong and other provinces were also compared. RESULTS: A total of 13 cases of laboratory-confirmed brucellosis were identified. 7 (53.8%) of the patients were male, 6 (46.2%) were female, with age ranging from 29 to 73 years old (median age: 51 years). 5 patients (38.5%) were from Guangdong province, while the remaining patients (61.5%) were from other provinces. The commonest risk factors of acquisition were consumption of undercooked meat and goat placenta. Patients from Guangdong province were found to be more likely to have prior placenta consumption. The commonest clinical presentations were fever, osteoarticular pain, urinary symptoms, splenomegaly, and lymphadenopathy. Spondylodiscitis/ peripheral joint arthritis (5 patients, 38.5%) was the most prevalent complication, while extra-osteoarticular complications including abdominal aortitis, hepatosplenic abscess, chest wall abscess, and epididymo-orchitis were observed in 4 other patients. Furthermore, it was demonstrated that MALDI-TOF MS is reliable in Brucella identification after additional of reference spectra with standard Brucella strain. CONCLUSIONS: Brucellosis, previously thought to be only found in northern China, is now increasingly seen in highly cosmopolitan part of southern China. MALDI-TOF MS in hospitals in China should include reference spectra with standard Brucella strain to aid bacterial identification in routine clinical practice. In addition to tuberculosis, typhoid fever and typhus, brucellosis should be considered in patients with fever of unknown origin in this locality.

[The mechanism of tenuigenin for eliminating waste product accumulation in cerebral neurons of Alzheimer's disease rats via ubiquitin-proteasome pathway].

OBJECTIVE: To explore the scavenging action of tenuigenin (TEN) on intracerebral amyloid ß protein (Aß) aggregation and the abnormal phosphorylated tau protein and its mechanism in Alzheimer's disease (AD) rats' brain. METHODS: Aß1-40 was injected into the right CA1 region hippocampus to establish the AD model. Successfully modeled rats were divided into the model group, the low, middle, high TEN group. Rats were administered with TEN (18.5, 37.0, 74.0 mg/kg) by gastrogavage. Besides, a sham-operation group was set up. Expression levels of Aß1-40 and Tau p-Ser262 were detected by immunohistochemistry. Expression levels of ubiquitin (Ub) and Ub-protein ligase E3 were measured by Western blotting.The content of 26S proteasome was detected by ELISA. RESULTS: Immunohistochemical results showed that the number of Aß and Tau p-Ser262 positively reacted neurons significantly increased in model group, when compared with the sham-operation group (P < 0.01). Results of Western blot showed expression levels of ubiquitinated protein were up-regulated and those of Ub-protein ligase E3 were down-regulated in the model group (P < 0.01). ELISA results showed that the content of 26S proteasome significantly decreased in AD rats' brain (P < 0.01). Compared with the model group, expression levels of Aß1-40, Tau p-Ser262, and Ub significantly decreased; expression levels of Ub-protein ligase E3 apparently increased; the content of 26S proteasome significantly increased in each TEN treatment group (P < 0.05, P < 0.01). Best effect was shown in 37.0 mg/kg and 74.0 mg/kg TEN groups. CONCLUSIONS: Ub proteasome pathway (UPP) participated in the occurrence of AD. TEN could obviously reduce intracere- bral Aß1-40 accumulation and abnormal tau phosphorylation.

Comparison of serum anti-Mullerian hormone levels following hysterectomy and myomectomy for benign gynaecological conditions.

OBJECTIVE: To compare serum anti-Mullerian hormone (AMH) levels following hysterectomy and myomectomy. STUDY DESIGN: Prospective longitudinal observational study. Serum AMH, follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels were measured pre-operatively (T1) and 2 days (T2) and 3 months (T3) following hysterectomy and myomectomy in 70 women aged 36-45 years. Hysterectomy (laparoscopy-assisted vaginal hysterectomy=10; total abdominal hysterectomy=25) with conservation of both ovaries for benign diseases of the uterus was performed in 35 women, and myomectomy (laparoscopy myomectomy=15; open myomectomy=20) was performed in another 35 women. The follow-up period was 3 months following surgery. The results were analysed using the t-test or one-way analysis of variance by repeated-measures ANOVA. RESULTS: Serum AMH in the hysterectomy group was 1.08±0.77 ng/ml at T1, 0.78±0.58 ng/ml at T2 and 0.81±0.58 ng/ml at T3; the level was significantly lower at T2 and T3 compared with T1. In the myomectomy group, the corresponding values were 1.54±0.95 ng/ml, 1.18±0.77 ng/ml and 1.50±0.58 ng/ml; serum AMH was significantly lower at T2 compared with T1, but the difference between T3 and T1 was not significant. There were no significant differences in serum FSH and LH in either group between these three time points. CONCLUSION: Serum AMH was significantly lower 2 days and 3 months following hysterectomy compared with the pre-operative level. Following myomectomy, serum AMH was significantly lower than the pre-operative level 2 days following the procedure, but was similar to the pre-operative level 3 months after surgery. Therefore, hysterectomy may have a more lasting adverse effect on ovarian reserve than myomectomy. A long-term study of AMH levels is needed.

Complete mitochondrial genome of Locusta migratoria migratoria (Orthoptera: Oedipodidae): three tRNA-like sequences on the N-strand.

The complete 16053 bp mitochondrial genome (mitogenome) sequence of Locusta migratoria migratoria has been determined. This mitogenome contains the base compositional biases and codon usage typical of metazoans, and the RSCU values indicate a negative correlation with the C and G contents in codon. The orientation and gene order of the L. migratoria migratoria is identical to Locusta migratoria migratoiodes. An unusual feature of the L. migratoria migratoria mitogenome is the presence of three tRNA-like structures on the N-strand: one tRNA(Ile)-like and two tRNA(Leu(CUN))-like sequences. The tRNA-like sequences have proper folding structures and anticodons sequences. Two repeated DNA sequences, Rpt I and Rpt II, were found in the A+T-rich region of the L. migratoria migratoria mitogenome. Both repeated sequences have various features. In the 5' region of Rpt I, a 51 bp fragment is localized in the srRNA gene; and there are two tandemly sub-repeated DNA sequences (sub-Rpts), Rpt 1-4, within Rpt I and Rpt II. One stem-loop structure on the N-strand that may be involved in the N-strand replication initiation was found in the A+T-rich region.

[DNA methylation in Drosophila, a review of recent studies].

DNA methylation is a key mechanism underlying epigenetic regulation. Fruit fly has been considered as a free DNA methylation organism until recently a few studies demonstrated that genomic methylated DNA is prevalent during the early embryonic development; but the overall methylation level in Drosophila is lower than in vertebrates and plants. The putative genomic DNA methylation systerm in Drosophila contains a methyltransferase termed dDNMT2 and a methyl-binding protein dMBD2/3. dDNMT2 shows significant homology to the mammalian methyltransferases DNMT2 family, and dMBD2/3 encodes a protein with distinct homology to mammalian methyl-binding proteins MBD2 and MBD3. Some studies also indicated that methylation pattern varies among different species of Drosophila. This article summarizes the recent progresses in studies of DNA methylation in Drosophila.

[Ultrasound-mediated microbubble cavitation enhances gene transduction in rat pulmonary endothelial cells partially by affecting membrane fluidity and cytoskeleton structure].

OBJECTIVE: To evaluate the effect of therapeutic ultrasound-induced microbubble's cavitation on plasmid gene transduction in rat pulmonary endothelial cells in relation to the changes of membrane fluidity and cytoskeleton structure. METHODS: Rat endothelial cells cultured in vitro were transfected with EGFP plasmid in the presence of protein microbubbles. During the transfection process, the cells were exposed to continuous 2 MHz ultrasonic irradiation for 30, 60, 90, 120 and 180 s (groups A, B, C, D and E, respectively) with the constant mechanical index (MI) of 1.0, or for 60 s with different mechanical index (MI) of 0.5, 0.75, 1.0, 1.5, and 1.8 (groups B1, B2, B3, B4 and B5, respectively). The changes of endothelial cytoskeletal structure and membrane fluidity were evaluated by immunofluorescence staining after the exposure. RESULTS: EGFP gene transduction increase obviously with prolonged echo irradiation and increased MI. The intensity of immunofluorescence staining, which represented endothelial membrane fluidity, was 0.173±0.013, 0.250±0.037, 0.364±0.022, 0.381±0.019, and 0.395±0.009 in groups A-E, as compared with 0.171±0.017, 0.255±0.026, 0.378±0.007, 0.382±0.009 and 0.397±0.008 in groups B1-B5, respectively. The recovery intensity of the immunofluorescence staining representing the changes in microtubulin of the cytoskeleton structure was 159.15±4.79, 188.23±6.20, 205.80±4.48, 208.99±8.34, and 213.70±5.09 in groups A-E, and was 176.84±3.10, 187.57±14.52, 206.41±11.66, 220.12±13.39 and 221.16±12.78 in groups B1-B5, respectively. The endothelial membrane fluidity and microtubule fluorescence recovery intensity increased remarkably compared with the baseline (P<0.01) within the MI range of 0.50-1.0 and the exposure time of 30-90 s, but underwent no further changes in response to prolonged exposure time (180 s) at the MI of 1.5 (P>0.05). No changes in microfilament fluorescence intensity were observed after exposure to different MI or irradiation time. CONCLUSION: Therapeutic ultrasound-mediated albumin microbubble cavitation allows enhances plasmid gene transduction without causing cytoskeleton damages. Increased endothelial membrane fluidity and changes in cytoskeleton structure, especially microtubulin, partially contribute to this enhancement.

[Development of a high-efficient assay for amplifying Vbeta-encoding genes of human T-cell receptor].

AIM: To develop an effective assay for amplifying human T-cell receptor (TCR) variable region of beta chain (Vbeta)-encoding genes. METHODS: Based on the property of the 26 subfamilies of human TCR Vbeta-encoding gene sequence, 34 sets of outer and 37 sets of inner sense primers were divided into 8 degenerate primer groups, and a set of outer and inner antisense primers located in conserved region beta chain (Cbeta) was designed for the amplification of the TCR Vbeta-encoding genes. In addition, a sequencing primer and a sense primer for amplifying Cbeta-encoding genes were designed. CD8 T-cell RNA was extracted and subjected to reverse transcription mediated by poly A, followed by a nested polymerase chain reaction (PCR) to amplify the 26 subfamilies of human TCR Vbeta-encoding genes. Jurkat T lymphoma cells were used as control. T-easy vector was employed to detect DNA sequencing of the cloned target genes. RESULTS: All the subfamilies of the Vbeta-encoding genes were obtained from CD8 T cells of a healthy donor, except the subfamily of Vbeta8 , was obtained from Jurkat cells. The results were confirmed by DNA sequencing of the cloned genes. CONCLUSION: The nested RT-PCR assay can effectively amplify human TCR Vbeta-encoding genes with broad spectrum, which is helpful for the cloning and functional study of the TCR expressed by antigen-specific cytotoxic T lymphocytes.

[Construction of an eukaryotic expression vector for PRL-2 and its effect on human hepatocellular carcinoma cell invasiveness and migration in vitro].

OBJECTIVE: To construct an eukaryotic expression vector for PRL-2 and evaluate its effect on the invasiveness and migration of a human hepatocellular carcinoma cell line. METHODS: RT-PCR was performed to amplify the complete PRL-2 open reading frame using the total mRNA of hepatocellular carcinoma HepG2 cells as the template. PRL-2 gene was inserted into the pGEM T easy vector and sequenced, and the correct PRL-2 sequence was subcloned into the mammalian expression vector pcDNA3.1+. The constructed PRL-2 vector was transfected into CL1 cells via lipofectamine, and the stable expression of PRL-2 mRNA was detected by RT-PCR, the expressed protein identified by immunohistochemistry and Western blotting, and the effect of PRL-2 on the adhesion ability of CL-1 cell evaluated with MTT assay 20 and 120 min after transfection. The effect of PRL-2 on the invasive migration of CL-2 cells was evaluated according to the number of cells penetrating the Matrigel layer of polycarbonate membrane of Boyden chamber. RESULTS: RT-PCR yielded a fragment of 504 bp and the inserted PRL-2 sequence was verified by sequence analysis. The subclones were identified by restriction endonuclease digestion, and a G418-resistant clone, PRL-2-CL1, was obtained after 8 weeks of selection. RT-PCR showed stable expression of PRL-2 mRNA, and Western blotting confirmed overexpression of PRL-2 protein in the transfected cells. PRL-2 increased the adhesion rate of CL-1 cells to fibronectin at 20 min and 120 min after transfection (P<0.05), and also the number of CL-1 cells penetrating the polycarbonate membrane from 10.0+/-3.7 to 44.8+/-2.6 (P<0.05). CONCLUSION: An eukaryotic expression vector of PRL-2 has been successfully constructed, which allows stable and efficient expression in CL-1 cell line. PRL-2 can promote cell adhesion and invasion activity of human hepatocellular carcinoma cells.