Molecular epidemiology of Streptococcus agalactiae in non-pregnant populations: a systematic review.

Streptococcus agalactiae (group B Streptococcus, GBS) has recently emerged as an important pathogen among adults. However, it is overlooked in this population, with all global efforts being directed towards its containment among pregnant women and neonates. This systematic review assessed the molecular epidemiology and compared how the lineages circulating among non-pregnant populations relate to those of pregnant and neonatal populations worldwide. A systematic search was performed across nine databases from 1 January 2000 up to and including 20 September 2021, with no language restrictions. The Joanna Briggs Institute (JBI) Prevalence Critical Appraisal Tool (PCAT) was used to assess the quality of included studies. The global population structure of GBS from the non-pregnant population was analysed using in silico typing and phylogenetic reconstruction tools. Twenty-four articles out of 13 509 retrieved across 9 databases were eligible. Most studies were conducted in the World Health Organization European region (12/24, 50 %), followed by the Western Pacific region (6/24, 25 %) and the Americas region (6/24, 25 %). Serotype V (23%, 2310/10240) and clonal complex (CC) 1 (29 %, 2157/7470) were the most frequent serotype and CC, respectively. The pilus island PI1 : PI2A combination (29 %, 3931/13751) was the most prevalent surface protein gene, while the tetracycline resistance tetM (55 %, 5892/10624) was the leading antibiotic resistance gene. This study highlights that, given the common serotype distribution identified among non-pregnant populations (V, III, Ia, Ib, II and IV), vaccines including these six serotypes will provide broad coverage. The study indicates advanced molecular epidemiology studies, especially in resource-constrained settings for evidence-based decisions. Finally, the study shows that considering all at-risk populations in an inclusive approach is essential to ensure the sustainable containment of GBS.

Analysis of external exposure dose monitoring results of interventional radiology staff in a hospital from 2018 to 2020 / 中国辐射卫生

@#<b>Objective</b> To analyze the monitoring results of external exposure dose of interventional radiology staff in a tertiary general hospital in Beijing, China, 2018—2020, and to provide a basis for safe guarding staff health and hospital radiation protection management. <b>Methods</b> A total of 321 interventional radiology staff in a hospital in Beijing were selected to collect information on the types of interventional work, positions, and personal dose monitoring results in 2018—2020. The dose monitoring results were analyzed using SPSS 22.0. <b>Results</b> The effective monitoring rate for the three years was 78.82%, 81.65%, and 96.85%, respectively, showing an increasing trend (<i>χ</i>²_trend = 16.134, <i>P</i> < 0.001). The annual dose equivalent per capita was 0.142, 0.142, and 0.265 mSv, respectively. The annual dose equivalent per capita in 2020 was significantly higher than those in 2018 (<i>H</i> = 24.562, <i>P</i> < 0.001) and 2019 (<i>H</i> = 39.378, <i>P</i> < 0.001). The annual dose equivalent per capita in 2020 was in the order of interventional clinician > interventional nurse > technician (<i>H</i> = 10.699, 6.562, <i>P</i> < 0.01). The annual dose equivalent per capitain 2020 was higher in the cardiology interventional department than in the comprehensive interventional, neuro interventional, and vascular surgery departments (<i>H</i> = 35.530, 37.614, 35.496, <i>P</i> < 0.001). <b>Conclusion</b> The number of interventional radiology staff monitored from 2018 to 2020 increased year by year, so did the effective monitoring rate.The external exposure dose was at low levels, which generally meets the requirements of national occupational exposure limits. Training on radiation protection for interventional radiology staff should be further strengthened to raise awareness of radiation protection.

Effects of paraquat on the proliferation of human neural stem cells via DNA methylation / 中华劳动卫生职业病杂志

Objective@#To investigate the effects of Paraquat on neural stem cell proliferation in vitro and explore the its mechanism based on DNA methylation pathway.@*Methods@#Nestin, β-tubulin III, and glial fibrillary acidic protein (GFAP) were detected by indirect immunofluorescence assay to evaluate self renewal and differentiation potentia of ReNcell CX human neural stem. The cells were treated with terminal concentrations of 0, 5, 25, 50, and 100μmol/L PQ for 24 hours, and the cells were induced by 50 μmol/L PQ for different time (6, 12, 24, 48 h). Cell viability was determined by MTT assay. The proliferation of neural stem cells was evaluated using Sox2/Brdu and Nestin/Brdu double immunofluorescence staining. The global DNA methylation level was assayed by MethyflashTM methylated DNA Quantification kit. The expression levels of Dnmts mRNA and protein were analyzed by quantitative reverse transcription polymerase chain reaction(qRT-PCR) and Western blot, respectively.@*Results@#Immunofluorescence showed that nestin was primarily expressed in proliferative neural stem cell and peotein biomarkers (β-tubulin III, GFAP) for neuron and astrocyte were expressed in differentiated cells. MTT assay showed PQ induced cell survival rate decrease in a time and dose dependent manner. Double immunfluorescence staining of cells showed colocalization of Sox2 and Brdu. The percentage of Brdu/Sox2 positive cells was significantly lower in the PQ-exposed (25, 50, 100μmol/L PQ treatment) groups compared to control (P<0.05); Meanwhile, The percentage of Brdu/Nestin positive cells was also significantly lower in the PQ-exposed(50,100μmol/L PQ treatment) groups compared to control (P<0.05). The results of global DNA methylation revealed a significant decrease in PQ-exposed groups (P<0.05). Western blot showed that compared with control group, the protein and mRNA levels of Dnmt1, Dnmt3a in PQ-exposed group were significantly decreased (P<0.05), but there was a significant increase in expression level of Dnmt3b in 50, 100 μmol/L PQ-treated group(P<0.05).@*Conclusion@#Paraquat could inhibite the proliferation of human neural stem cells through reducing the level of DNA methylation reaction by suppressing the protein expression and transcription of DNA methylated transferase(Dnmts).

The regulation of tight junction protein via PKCα/β for abnormal permeability of brain microvascular endothelial cells exposed to paraquat / 中华劳动卫生职业病杂志

Objective@#To explore if conventional protein kinase C (cPKC: PKCα and PKCβ) contributes to paraquat (PQ) -induced abnormal permeability of mouse brain microvascular endothelial cells (BMECs) via the regulation of tight junction (TJ) proteins.@*Methods@#The immortalized mouse brain endothelial cell line (bEnd.3) was used to establish a monolayer blood-brain barrier (BBB) model. In order to evaluate the function of the in vitro BBB model, the transendothelial electrical resistance (TEER) and permeability were measured by a Millicell-ERS volt-ohmmeter and sodium fluorescent (Na-FLU) , respectively. MTT assay was used to determine the relative survival rate of cells. The dose-response relationship was determined by treating cells with 0, 50, 100, 200, and 300 μmol/L PQ for 24 hours. The time-response relationship was determined by treating cells with 200 μmol/L PQ for 6, 12, 24, 48, and 72 hours. After the treatment of cells with 0, 100, 200, and 300 μmol/L PQ for 24 hours, the protein and mRNA expression levels of ZO-1, Occludin, and Claudin-5 were measured by immunofluorescence (IF) and quantitative real-time RT-PCR (qRT-PCR) , respectively; the expression of PKCα, PKCβ, phosphorylated (p) -PKCα, and p-PKCβ was determined by Western blot. After the treatment of cells with 200? mol/L PQ for 24 hours following the pretreatment with a classical PKC inhibitor (Go 6983, 1 μmol/L) for 1 hour, the protein expression of ZO-1, Occludin, Claudin-5, p-PKCα, and p-PKCβ was measured by Western blot.@*Results@#The TEER of the bEnd. 3 cells increased gradually with the cell culture time, and reached a peak value of 114.3±6.9 Ω·cm2 on day 6. According to the permeability analysis by Na-FLU, cell permeability gradually decreased with the cell culture time, and reached 1.7±0.2 cm/min on day 6, suggesting a well-behaved barrier function of cells. Compared with the control group, the survival rates of the bEnd.3 cells were significantly reduced after exposure to 100, 200, or 300 μmol/L PQ for 24 hours (P<0.05) , or after exposure to 200 μmol/L PQ for 6, 12, 24, 48, or 72 hours (P <0.05) , indicating a dose-and time-dependent relationship. The IF and qRT-PCR results showed that the protein and mRNA expression levels of ZO-1, Occludin, and Claudin-5 were significantly reduced with the increase in the concentration of PQ (P<0.05) . The Western blot analysis showed that compared with the control group, cells exposed to PQ had significantly higher protein expression of p-PKCα and p-PKCβ and significantly lower protein expression of ZO-1, Occludin, and Claudin-5 (P<0.05) . Compared with the PQ treatment group, the Go 6983 intervention group had significantly higher protein expression of ZO-1, Occludin, and Claudin-5 and significantly lower protein expression of p-PKCα and p-PKCβ (P<0.05) .@*Conclusion@#By activation of cPKC (PKCα and PKCβ) , PQ reduces the protein and mRNA expression of TJ proteins and enhances the permeability of murine BMECs.

Role of MAPK signaling pathway in epithelial-mesenchymal transition of type II alveolar epithelial cells induced by Paraquat / 中华劳动卫生职业病杂志

Objective@#To investigate the roles of p38 mitogen-activated protein kinases (p38 MAPK) , extracellular regulated protein kinases (ERK) and c-Jun N-tenninal kinases (JNK) of MAPK signaling pathway in Paraquat-induced epithelial to mesenchymal transition (EMT) of type II alveolarepithelial cells.@*Methods@#RLE-6NT cells were incubated with different concentrations of PQ (0, 25, 50, 100μmol/L) for 6, 12 and 24 h. Cell morphology alteration was observed under phase-contrast microscopy. Cell viability was determined using an MTT assay. Cell migration ability was detected using scratch wound assay. Protein expression of P-p38 MAP, P-Erk1/2, P-JNK, E-cad, ZO-1, Vimentin and а-SMA were detected by western blot. The level of genes related to fibrosis (COL-I, COL-III, FN and FSP-1) were analyzed via quantitative real-time RT-PCR.@*Results@#Cell morphology started to undergo EMT changes with a phenotype characteristic of mesenchymal cells, including an elongated shape and a lack of tight cell-cell adhesions induced by 100μmol/L PQ treatment in a time-dependent manner. MTT showed that cell viability decreased with increasing PQ concentration (50、100、200、300 μmol/L PQ treatment for 24 h) and increasing treatment time (200 μmol/L PQ treatment for 6, 12, 24, 36, 48 h) . Compared to control group, the expressions of the epithelial phenotype marker E-cad and ZO-1 significantly decreased with PQ treatment (50, 100μmol/L) in a time-dependent manner (P<0.05) . Additionally, the level of the mesenchymal marker (a-SMA, vimentin) dramatically increased with PQ treatment in the same concentration-and time-dependent manner (P<0.05) . Cell migration ability was markedly increased after 24 h of 100 μmol/L PQ treatment compared to control (P<0.05) . The phosphorylated forms of p38 MAPK, Erk1/2, and JNK were increased at 24 h after stimulation with PQ (P<0.05) . This PQ induced (100 μmol/L) phosphorylation was markedly attenuated in the presence of the p38 MAPK, ERK and JNK inhibitors (SB-203580, SP-600125 and PD98059) respectively. Furthermore, RT-PCR showed that PQ significantly induced the upregulation expression of COL I and III mRNA, Fn, and FSP-1 mRNA (P<0.05) .@*Conclusion@#PQ-induced pulmonary fibrosis occurs via EMT, which is mediated by the MAPK pathway.

The value of whole tumors volume based T2 histogram analysis for differential diagnosis in pediatric posterior fossa tumors / 中华放射学杂志

Objective To study the value of whole tumors T2WI gray histogram analysis for differential diagnosis of three commonly presented pediatric posterior fossa tumors. Methods A retrospective analysis was conducted to compare brain MRI examination and pathology diagnosis of 133 cases of posterior fossa tumors in pediatric patients in our hospital.Among them, there were 49 cases of ependymoma(there were 25 males and 24 females), 36 cases of astrocytoma(WHO grade Ⅰ)(there were 19 males and 17 females), 48 cases of medulloblastoma(there were 36 males and 12 females),aged 1 to 14 years old, with an average (7±2) years old. Respectively draw the region of interest (ROI) in the T2 MR transaxial images of three groups on each layer of tumor level by using Mazda software and analyze the whole tumors gray histogram, including mean,variance, kurtosis,skewness, perc.01%,perc.10%,perc.50%,perc.90% and perc.99%.The histogram parameters of the three groups were not normally distributed. The Kruskal-Wallis test was used to compare the three groups. Bonferroni test was used to compare the two groups to find out statistical significance of each parameter. Results Through histogram analysis of 9 parameters, these 9 parameters were statistically significant (all P <0.05),including mean,variance,kurtosis,skewness, perc.01%,perc.10%,perc.50%,perc.90% and perc.99%. The sensitivity of skewness to differentiate ependymoma and the astrocytoma was 69.4％, the specificity was 77.8％, the area under the curve was 0.744, and the best cut-off value was-0.08. The sensitivity of kurtosis to differentiate astrocytoma and the medulloblastoma was 95.8％, the specificity was 97.2％ and the area under the curve was 0.972, the cut-off was 1.68. The sensitivity of kurtosis to differentiate ependymoma and the medulloblastoma was 91.7％, the specificity was 89.8％and the area under the curve was 0.932,the cut-off was 1.90.They had a high identification efficiency. Conclusions The T2WI gray histogram analysis based whole tumors is helpful for the dignosis of three types of pediatric posterior fossa tumors. Skewness has a high diagnostic efficiency to differentiate ependymoma and the astrocytoma. Kurtosis has a high diagnostic efficiency to differentiate ependymoma and the medulloblastoma. Kurtosis has a high diagnostic efficiency to differentiate ependymoma and medulloblastoma.

Whole-tumor histogram analysis of apparent diffusion coefficient maps in grading diagnosis of ependymoma / 中华放射学杂志

Objective To study the value of whole tumors volume based apparent diffusion coefficient histogram analysis in grading diagnosis of ependymoma. Methods Seventy?one patients with ependymal tumors were retrospectively analyzed, including 13 cases of WHOⅠ, 28 cases of WHOⅡ, 30 cases of WHO Ⅲ. Regions of interest (ROI) in the apparent diffusion coefficient maps of three groups on each layer of tumor level were drawn by using MaZda software and were analyzed using the whole tumors gray histogram. The histogram parameters of the three groups all fitted the normal distribution and homogeneity test of variance. The ANOVA analysis was used to compare the three groups. LSD-t test was used to compare the two groups to find out statistical significance of each parameter. Results Through histogram analysis of 9 parameters, three parameters were statistically significant (P<0.05), including variance, perc. 01％ and perc. 10％. The remaining 6 parameters had no significant difference between the three groups (P>0.05). Between the WHOⅠand the WHOⅡ, the sensitivity of perc.10％was 85.7％, the specificity was 87.7％, the area under the curve was 0.835, and the best cut-off value was 131.33. Between the WHOⅠand the WHOⅢ, the sensitivity of perc.10％was 85.7％, the specificity was 100.0％, the area under the curve was 0.872, and the cut-off was 126.5.Between the WHOⅡand the WHOⅢ, the sensitivity of variance was 68.4％, the specificity was 79.6％, the area under the curve was 0.794, and the cut-off was 2645.7. They had a high identification efficiency. Conclusion Whole-tumor histogram analysis of apparent diffusion coefficient maps could provide ancillary diagnostic value in grading diagnosis of ependymoma. Perc.10％and variance had a high diagnostic efficiency.

The MRI findings of cavernous hemangioma in the thoracic spinal epidural space / 实用放射学杂志

Objective To explore the MRI features of cavernous hemangioma in the thoracic spinal epidural space,to improve the recognition of the disease.Methods The clinical,pathological and MRI data of 7 cases with cavernous hemangioma in the thoracic spinal epidural space confirmed by surgery and pathology were analyzed retrospectively.Results 7 cases of cavernous hemangioma in the thoracic spinal epidural space were included in our study,all cases underwent MRI contrast enhancement examination and 6 of them underwent conventional MRI examination.On T1WI,4 cases showed hypointensity,2 cases showed slightly hypointensity and 1 case showed mixed slightly hypointensity.On T2WI,5 cases showed slightly hyperintensity,1 case showed slightly hypointensity. On fat suppression sequence,5 cases showed hyperintensity,1 case showed heterogeneous hyperintensity.On diffusion-weighted imaging (DWI),7 cases showed obviously hyperintensity.On contrast-enhanced images,the lesions enhanced homogeneously in 5,enhanced heterogeneously in 2.Conclusion MRI can display the location,appearance and enhancement pattern of thoracic spinal epidural cavernous hemangioma distinctly,while definite diagnosis of which still depends on pathology.

Application of MRI histogram analysis in assessment risk of medulloblastoma recurrence / 中国介入影像与治疗学

Objective To explore the value of MRI histogram analysis in the risk assessment of medulloblastoma recur rence.Methods The data of 28 patients pathologically confirmed of medulloblastoma was analyzed retrospectively.All patients were divided into recurrent group and the non recurrent group (each n=14).The ROIs were drawn on the maximum level of enhanced MR sagittal images,and the histogram analysis were performed using the software named Mazda.The statistical analysis was performed on the histogram parameters to find out the different characteristics between the two groups,and the ROC curve was drawn to evaluate its diagnostic efficacy for recurrence of medulloblastoma.Results In all of the 9 parameters which are extracted from histogram,kurtosis had statistical significance between the 2 groups (P=0.018).The area under the ROC curve was 0.776 (P=0.018),and the sensitivity and specificity of kurtosis in the risk assessment of medulloblastoma recurrence were 64.3％ and 71.4％,respectively.Conclusion MRI histogram analysis can be an important method to assess the risk of medulloblastoma recurrence.