[The value of cell free DNA of Mycobacterium tuberculosis in the early diagnosis of tuberculous meningitis].

Objective: To detect the cell-free DNA of Mycobacterium tuberculosis (Cf-TB) in the cerebrospinal fluid (CSF) of patients with tuberculous meningitis (TBM), and to assess the diagnostic value of this method for TBM. Methods: We prospectively included patients with suspected meningitis from the Department of Tuberculosis, Beijing Chest Hospital, Department of Neurology, Beijing Chaoyang Hospital and Department of Neurology, 263 Hospital of the People's Liberation Army from September 2019 to March 2022. A total of 189 patients were included in this study. Among them, 116 were male and 73 were female, aged from 7 to 85 years, with an average of (38.5±19.1) years. The CSF specimens of the patients were collected for Cf-TB, MTB culture and Xpert MTB/RIF. SPSS 20.0 was used for statistical analysis and the difference was statistically significant with P<0.05. Results: Among the 189 patients, there were 127 patients in the TBM group and 62 patients in the non-TBM group. The sensitivity of Cf-TB was 50.4% (95%CI 41.4%-59.3%), the specificity was 100% (95%CI 92.7%-100.0%), the positive predictive value was 100% (95%CI 92.9%-100.0%), and the negative predictive value was 49.6% (95%CI 40.6%-58.6%). Using clinical diagnosis as the gold standard, the sensitivity of Cf-TB was 50.4% (64/127), which was significantly higher than that of MTB culture (8.7%, 11/127) and Xpert MTB/RIF (15.7%,20/127) (all P<0.001). Using etiology as the gold standard, the sensitivity of Cf-TB was 72.7% (24/33), which was significantly higher than that of MTB culture [33.3%, 11/33, (χ2=10.28, P=0.001)] and was similar to Xpert MTB/RIF (60.6%, 20/33) (χ2=1.091, P=0.296). Conclusion: The sensitivity of the Cf-TB test was significantly higher than that of CSF MTB culture and Xpert MTB/RIF. Cf-TB may provide evidence for earlier diagnosis and treatment of TBM.

[Mycobacterium xenopi pulmonary disease:report of 3 cases and literature review].

Objective: To analyze the clinical manifestations, radiographic characteristics and prognosis of Mycobacterium xenopi pulmonary disease, in order to improve diagnosis and treatment of the disease. Methods: Using "Mycobacterium xenopi, pulmonary disease" as the search term, from February 15, 2007 to February 21, 2021, a total of 1 264 cases were retrieved in the PubMed database. In the Wanfang database, using "Mycobacterium xenopi, pulmonary disease" as the search term, from February 15, 2007 to February 21, 2021, no related document was retrieved. In the CNKI database, "Mycobacterium xenopi, pulmonary disease" was used as the search term, and one relevant case report was retrieved, but did not meet the diagnostic criteria of Mycobacterium xenopi pulmonary disease issued by American Thoracic Society in 2007. The 1 264 cases from the literature and 3 cases of our institution were used for review. Results: Our 3 cases were elderly males complaining of cough and expectoration, and had underlying lung diseases. The imaging examination showed cavitary lesions. All of them had positive sputum smear for acid-fast bacillus and negative Xpert MTB/RIF examination. Mycobacterium xenopi was isolated at least 2 times from sputum samples. Although prescribed with chemotherapy, case 1 and case 2 died 4 years and 2 years later, respectively, after the diagnosis. Case 3 got sputum conversion, symptom improvement and radiographic responses after 30-month chemotherapy. Conclusions: The clinical manifestations of Mycobacterium xenopi pulmonary disease are atypical. For patients with positive sputum smear for acid-fast bacillus and negative Xpert MTB/RIF examination and conventional mycobacterial culture, Mycobacterium xenopi pulmonary disease should be considered. The disease deserves further attention from clinicians due to poor prognosis.

[Frequency and clinical relevance of rapidly growing mycobacterium isolated from respiratory samples].

OBJECTIVE: To assess the frequency and clinical relevance of rapidly growing mycobacterium (RGM) isolates in a tuberculosis referral center in Beijing, China. METHODS: All isolates were identified by using targeted gene sequencing. RESULTS of species identification for 228 nontuberculous Mycobacterium (NTM) isolates from respiratory samples were analyzed, and available medical files of patients from whom NTM were isolated were reviewed retrospectively. Diagnostic criteria for RGM pulmonary disease issued by the American Thoracic Society (ATS) were used to determine clinical relevance. RESULTS: Isolates of Mycobacterium abscessus (M.abscessus) and Mycobacterium fortuitum (M.fortuitum) accounted for 28.9% (66 isolates) and 8.8% (20 isolates)of NTM isolates, respectively. Sixty-six M. abscessus isolates from 32 patients had evaluable medical files, including 28 cases diagnosed as definite M. abscessus lung disease, and 4 as probable M. abscessus lung disease. Eight M. fortuitum isolates from 8 cases had evaluable medical files, and all of them were diagnosed as unlikely lung disease. Mycobacteria Growth Indicator Tube (MGIT) was more effective to diagnose M. abscessus lung disease, as compared with Lowestein-Jensen medium (23/24 vs 18/28). CONCLUSIONS: RGM is a common NTM in our institute. M. abscessus is mostly associated with RGM lung disease, but M. fortuitum is not.

Band tail-induced photoluminescence broadening in heavily In-doped n-type ZnO nanowires.

We have demonstrated that photoluminescence (PL) is a non-damaging and powerful tool for the characterization of heavily-doped semiconductor nanostructures such as n-ZnO nanowires. The PL shows a redshift and a Gaussian-shaped low-energy wing, indicating a broadening mechanism governed by the impurity band. The electron concentration can be estimated from the PL linewidth.

[Analysis of language and influencing factors of children with speech disorder in Beijing].

Objective: To investigate the features and influencing factors of language in children with various types of speech disorders. Methods: A case-control study was carried out, 262 children with speech disorder had been diagnosed at the language-speech clinic of the Center of Children's Healthcare, Children's Hospital, Capital Institute of Pediatrics from January 2021 to November 2023, the children with speech sound disorder as the speech sound disorder group, the children with developmental stuttering as the stuttering group. There were 100 typically-developed children who underwent physical checkups at the Center of Healthcare during the same period as the healthy group. All children experienced a standardized evaluation of language with diagnostic receptive and expressive assessment of mandarin-comprehensive(DREAM-C) and questionnaire, One-way ANOVA and LSD test were conducted to compare the differences in overall language, receptive language, expressive language, semantics, and syntax scores among 3 groups of children. According to the results of DREAM-C, the children with speech disorder were divided into language normal group and language delay group. Chi-square test and multivariate Logistic regression were implemented to analyze the association between the linguistic development of children with speech disorder and potential influential factors. Results: There were 145 children in the speech sound disorder group, including 110 males and 35 females respectively, with an age of (5.9±1.0) years; 117 children in the stuttering group, including 91 males and 26 females, with an age of (5.8±1.0) years; 100 children in the healthy group, including 75 males and 25 females, with an age of (5.7±1.2) years. The variations in overall language, expressive language, and syntax scores among 3 groups of children were statistically significant (92±18 vs.96±11 vs. 98±11, 81±18 vs. 84±14 vs. 88±13, 87±16 vs. 89±11 vs. 91±10, F=5.46, 4.69, 3.68, all P<0.05). Pairwise comparison revealed that the speech sound disorder group had lower scores in overall language, expressive language, and syntactic compared to the healthy group, and the differences were statistically significant (all P<0.01) and the overall language score was lower than that of children with stuttering (P<0.05). In terms of overall language and expressive language, there was a statistically significant difference in the incidence of language delay among the three groups of children (15.9% (23/145) vs. 20.5% (24/117) vs. 7.0% (7/100), 46.2% (67/145) vs. 39.3% (46/117) vs. 26.0% (26/100); χ2=7.93, 10.28; both P<0.05). In terms of overall language, the stuttering group took up the highest proportion. In terms of expressive language, the speech sound disorder group accounted for the highest amount. The incidence of language delay in children with speech disorder was 44.3% (116/262). Non-parent-child reading, daily screen time ≥1 hour and screen exposure before 1.5 years of age are risk factors for the development of language in children with speech disorder (OR=1.87, 2.18, 2.01; 95%CI 1.07-3.27, 1.23-3.86, 1.17-3.45; all P<0.01). Negative family history are protective factors for the progress of language ability (OR=0.37, 95%CI 0.17-0.81, P<0.05). Conclusions: Children with speech disorder tend to have easy access to language delay, especially in expressive language and syntax. The occurrence of language delay in children with speech disorder is tightly connected with factors such as the family medical history, parent-child reading, screen time, etc. Attention should be paid to the development of language in children who suffer from speech disorder.

Sphingosine kinase-1 mediates BCR/ABL-induced upregulation of Mcl-1 in chronic myeloid leukemia cells.

The signaling mechanisms responsible for BCR/ABL-induced regulation of Mcl-1 expression in chronic myelogenous leukemia (CML) cells remain unclear. In this study, we show that BCR/ABL could upregulate sphingosine kinase-1 (SPK1) expression via multiple signal pathways, including mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K) and Janus kinase 2 (JAK2), leading to increase cellular SPK1 activity in CML cells. Retrovirus-mediated overexpression of bcr-abl gene in NIH-3T3, Ba/F3 and HL-60 cells results in upregulation and increased cellular activity of SPK1, whereas treatment of CML cells with specific inhibitors of the BCR/ABL, PI3K, MAPK and JAK2 pathways decreases BCR/ABL-induced SPK1 expression and cellular activity. BCR/ABL also induces upregulation of Mcl-1 expression in CML cells. Inhibition of SPK1 by adenovirus-mediated transfer of small interfering RNA or N,N-dimethylsphingosine reduced expression of Mcl-1 in CML cells. Our data indicated that BCR/ABL induces SPK1 expression and increases its cellular activity, leading to upregulation of Mcl-1 in CML cells. SPK1 silencing enhances the STI571-induced apoptosis of CML cell lines. It is suggested that SPK1 may be a potential therapeutic target in CML.

Sphingosine kinase 1 participates in insulin signalling and regulates glucose metabolism and homeostasis in KK/Ay diabetic mice.

AIMS/HYPOTHESIS: The aim of this study was to determine the potential role of sphingosine kinase 1 (SPHK1), a key sphingolipid metabolic enzyme, in glucose metabolism and homeostasis. METHODS: SMMC-7721 hepatoma cells and C2C12 myotube cells were used to explore the role of SPHK1 in glucose uptake in vitro. KK/Ay type 2 diabetic mice, which were transfected with adenovirus harbouring the human SPHK1 gene by i.v. injection, were used to investigate the glucose-lowering effects of SPHK1 in vivo. RESULTS: The basal glucose uptake and the insulin-stimulated glucose uptake in both 7721 cells and C2C12 cells were markedly enhanced when SPHK1 was overexpressed by adenovirus-mediated gene transfer, whereas they were substantially reduced when the expression of SPHK1 was inhibited or the activity of SPHK1 was blocked. Insulin could activate SPHK1 of both cell lines in a dose-dependent manner. SPHK1 gene delivery significantly reduced the blood glucose level of KK/Ay diabetic mice, but had no effect on that of normal animals. It also attenuated elevated levels of plasma insulin, NEFA, triacylglycerol, cholesterol and LDL, significantly ameliorated hyperglycaemia-induced injury of liver, heart and kidney, and enhanced phosphorylation of insulin-signalling kinases such as Akt and glycogen synthase kinase 3beta in livers of the diabetic animals. CONCLUSIONS/INTERPRETATION: SPHK1 is involved in insulin signalling and plays an important role in the regulation of glucose and fat metabolism; adenovirus-mediated SPHK1 gene transfer might provide a novel strategy in the treatment of type 2 diabetes mellitus.