Epidemic characteristics of Mycoplasma pneumoniae infection: a retrospective analysis of a single center in Suzhou from 2014 to 2020.

Background: Mycoplasma pneumoniae (M. Pneumoniae) is a common pathogen of respiratory tract infections, but there is still a lack of detailed investigation on the large sample of M. Pneumoniae infection in the all age population. And patients with severe M. Pneumoniae pneumonia (SMPP) still have a certain risk of death. How to identify the clinical characteristics and population of patients with SMPP as soon as possible is still an urgent problem in clinical practice. Methods: Demographic characteristics, patient clinical information, and laboratory data of 81,131 patients with respiratory tract infections (RTIs) in the Affiliated Suzhou Hospital of Nanjing Medical University from 2014 to 2020 were retrospectively collected from all patient records. The serum particle agglutination (PA) test was used to determine M. Pneumoniae infection by detecting specific antibodies. The white blood cell count, the proportion of neutrophils and lymphocytes, C-reactive protein (CRP) and lactate dehydrogenase (LDH) levels between children and adults with SMPP were compared by Student's t-test; other clinical features were analyzed by χ2 test or Fisher's exact test. Results: A total of 81,131 patients with RTIs were included, and 21,582 (26.60%) M. Pneumoniae immunoglobulin M (IgM)-positive patients were detected. From 2014 to 2020, the annual proportions of M. Pneumoniae RTIs were 23.60%, 28.18%, 38.08%, 27.05%, 23.44%, 25.26%, and 18.33%, respectively. In terms of seasonal distribution, April-June and September-November were the peak seasons of M. Pneumoniae infection each year. Children and women have a high proportion of M. Pneumoniae infection. The peak age of M. Pneumoniae infection was between 4 and 14 years old. There were 301 cases of SMPP, including 281 children and 20 adults (8 cases of pregnant women). Children and pregnant women accounted for a high proportion of SMPP. Children with SMPP had more extrapulmonary symptoms, multilobar infiltrates, and increased CRP and LDH levels compared with adults. Conclusions: M. Pneumoniae infection has seasonal, sex, and age distribution trends. Children and pregnant women accounted for a high proportion of SMPP. Extrapulmonary symptoms, multilobar infiltrates, and increased CRP and LDH levels may be helpful to identify SMPP in children than in adults.

Zoledronic acid inhibits infiltration of tumor-associated macrophages and angiogenesis following transcatheter arterial chemoembolization in rat hepatocellular carcinoma models.

Hepatic transcatheter arterial chemoembolization (TACE), a minimally invasive procedure to block the blood supply of tumors and release of cytotoxic agents, is preferentially applied to patients with hepatocellular carcinoma (HCC) who are not able to receive radical treatments. However, the long-term effects of TACE are unsatisfactory, as the microenvironment following procedure stimulates tumor angiogenesis, which promotes recurrence and metastasis of residual tumors. Tumor associated macrophages (TAMs) have been revealed to stimulate tumor growth and angiogenesis associated with poor prognosis in HCC. The present study focused on the changes in TAMs following TACE, and explored the effects of TACE in combination with the TAM inhibitor zoledronic acid (ZA) in rat HCC models. Orthotropic HCC rats were divided into three groups: Sham TACE, TACE alone and TACE combined with ZA treatment. At 7 or 14 days following TACE, tumor growth was evaluated by magnetic resonance imaging (MRI). Infiltration of TAMs was assessed by histological analysis and flow cytometry. Tumor angiogenesis was measured as the mean vessel density, and initial slope was calculated from dynamic contrast enhancement MRI. Local and systemic levels of vascular endothelial growth factor (VEGF) were determined by western blotting or an ELISA, respectively. The results revealed that TACE inhibited tumor growth at 7 days following the procedure, but this inhibition was attenuated at 14 days following the procedure compared with the sham TACE control. If combined with ZA treatment, TACE exhibited a stable inhibition effect on tumor growth until the end of observation. Investigation of the underlying mechanisms demonstrated that TACE combined with ZA treatment inhibited infiltration of F4/80 positive TAMs and tumor angiogenesis compared with the TACE alone group at 14 days following the procedure. Additionally, the combination treatment significantly inhibited secretion of VEGF in the present models. In conclusion, ZA treatment enhanced the effects of TACE through inhibiting TAM infiltration and tumor angiogenesis in rat HCC models.

Suppression of cyclin D1 by plasmid-based short hairpin RNA ameliorated experimental pulmonary vascular remodeling.

Our previous study has demonstrated that a plasmid-based short hairpin RNA (shRNA) against cyclin D1 could attenuate the pulmonary artery smooth muscle cell (PASMC) proliferation and pulmonary vascular remodeling in smoking rats. In this report, we examined the efficiency of this shRNA plasmid in monocrotaline-induced pulmonary vascular remodeling. A single injection of monocrotaline induced pulmonary vascular remodeling and cyclin D1 over-expression in pulmonary vascular smooth muscle. The shRNA successfully suppressed the up-regulation of cyclin D1 in pulmonary vessels of monocrotaline-treated rats. Moreover, this shRNA decreased the percentage of muscularized vessels and the wall thickness of pulmonary vessels. So, we concluded that plasmid-based shRNA against cyclin D1 ameliorated pulmonary vascular remodeling in monocrotaline-treated rats. Cyclin D1 might be a potential target for the therapy of pulmonary vascular remodeling and pulmonary hypertension.

Expression of the Th1-specific cell-surface protein Tim-3 increases in a murine model of atopic asthma.

T-cell immunoglobulin- and mucin-domain-containing molecule-3 (Tim-3) is preferentially expressed on Th1-helper type T-cells and functions to repress the Th1-mediated immune response. However, the role of Tim-3 during the inflammatory pathogenesis of asthma remains unclear. This study determines the expression level of Tim-3 in CD4+ T-cells within the peripheral blood and bronchoalveolar lavage fluid (BALF) isolated from a murine model of atopic asthma and explores the potential role of Tim-3 during the inflammatory response. Mice were randomly divided into normal control, asthma day 1, and asthma day 7 groups, and peripheral blood T lymphocytes and BALF cells were collected. The ratio of Tim-3+/CD4+ cells among the total CD4+cell populations from peripheral blood and BALF was determined by flow cytometry, and the expression of the Tim-3 mRNA was determined by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR). In contrast with the normal control group, the ratio of Tim-3+/CD4+:CD4+ cells and the level of Tim-3 mRNA in both the peripheral blood T lymphocytes and BALF cells among the asthma day 1 and asthma day 7 groups were significantly increased (p < 0.01), and those in the asthma day 7 group were higher than the asthma day 1 group (p < 0.05). There was also a positive correlation between the ratio of Tim-3+/CD4+:CD4+ detected in BALF and that the ratio detected in peripheral blood T lymphocytes (r = 0.84, p < 0.01). Therefore, the expression of Tim-3 is increased in CD4+ T-cells following airway challenge and likely affects asthma-induced inflammation by repressing the Th1-mediated immune response.