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BACKGROUND: To analyse clinical characteristics, antibiotic susceptibility, and risk factors for mortality in paediatric invasive pneumococcal disease (IPD) in Beijing. METHODS: Paediatric IPD patients in our hospital were retrospectively collected from 2012 to 2017. Clinical manifestations, laboratory tests, antimicrobial susceptibility and serotype of isolates, and risk factors for mortality of IPD were analysed. RESULTS: Overall, 186 IPD cases were enrolled. The major manifestations were meningitis (76), pneumonia with bacteraemia (60), bacteraemia without focus (21), and pneumonia with empyaema (22). Of 72 cases with underlying diseases, leukaemia (18.0%), congenital heart disease (15.3%), primary immunodeficiency disease (12.5%), nephrotic syndrome (12.5%), and cerebrospinal fluid leakage (12.5%) were most common. In total 96.9% of isolates would have been covered by the pneumococcal conjugate vaccine (PCV13), including 19F (32.8%), 19A (23.4%), 4 (17.2%), and 23F (9.4%). Nonsusceptibility rates of penicillin, cefotaxime, and cefepime among nonmeningitis patients increased between 2012 and 2017; The mortality rate was 21.5%. Meningitis, respiratory failure, multiple organ failure, and white blood cell count < 4000 cells/µL were independent risk factors for mortality. CONCLUSION: Meningitis was the most common clinical manifestation of IPD, and was frequently associated with death. Strains in the PCV13 vaccine would cover most of the cases, and so wider use of PCV13 should be considered.
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Antibacterianos , Infecciones Neumocócicas , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Beijing/epidemiología , Niño , Farmacorresistencia Bacteriana , Humanos , Lactante , Infecciones Neumocócicas/tratamiento farmacológico , Infecciones Neumocócicas/epidemiología , Vacunas Neumococicas , Estudios Retrospectivos , Factores de Riesgo , Serogrupo , Serotipificación , Streptococcus pneumoniaeRESUMEN
Daxing'an Mountains is one of regions in China with the most significant climate change. Larix gmelinii and Pinus sylvestris var. mongolica are the most important species in this area. The study of their radial growth response to climate change would provide a scientific basis for predicting the dynamics of boreal forests under climate change. A total of 451 tree-ring cores of L. gmelinii and P. sylvestris var. mongolica were collected from six sites in the Daxing'an region, and 12 standard chronologies were established. We compared the tree growth trend since 1900, and analyzed their response to the climate factor in each site using Pearson correlation analysis. Effects of temperature and precipitation on the annual radial growth of L. gmelinii and P. sylvestris var. mongolica were investigated by linear mixed models. The time stability of the relationship between two species growth-climate was compared by moving correlation. The results showed that the radial growth of L. gmelinii was negatively correlated with mean temperature in March and positively correlated with precipitation in the previous winter and July of current year. The radial growth of P. sylvestris var. mongolica was positively correlated with temperature in August and precipitation in the growing season (from May to September) of current year. Snow in winter played an important role in promoting the radial growth of L. gmelinii, whereas precipitation in summer limited the radial growth of P. sylvestris var. mongolica. The responses of L. gmelinii and P. sylvestris var. mongolica to climate change were significantly different, which affected tree growth, species composition, and spatial distribution in the boreal forests.
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Larix , Pinus sylvestris , China , Cambio Climático , ÁrbolesRESUMEN
BACKGROUND: This study was aimed to investigate the clinical and molecular epidemiology of Staphylococcus aureus (S. aureus) isolated from Chinese children and determine the possible relationship among the accessory gene regulator (agr) groups and genotypes, as well as among the virulence genes and disease types. METHODS: S. aureus strains were isolated from Beijing Children's Hospital between October 2017 and October 2019. The isolates and 19 virulence genes were characterized using multi-locus sequence typing, staphylococcal protein A (spa), staphylococcal cassette chromosome mec, and agr typing. RESULTS: A total of 191 non-repetitive S. aureus clinical isolates were divided into 33 sequence types (STs), 18 clonal complexes (CCs), and 59 spa types. ST59 (39.8%), t437 (37.7%), and agr I (84.8%) were the predominant types. CC59, CC25, CC22, CC951, CC8, and CC398 belonged to agr I. CC5 and CC15 were assigned to agr II, and CC30 was characterized as agr III. CC121 was classified under agr IV. The eta, etb, and bbp genes were more prevalent in agr IV (P < 0.001 for each), while tst was more prevalent in agr group III compared to the other groups (P < 0.001). Nearly all isolates that harbored lukS/F-PV belonged to agr I (P = 0.005). However, the correlation between disease types and agr groups was not significant (P > 0.05). CONCLUSIONS: An association among the agr groups and genotypes, as well as specific toxin genes, was observed among the S. aureus strains isolated from Chinese children. However, a statistical correlation was not found among the agr groups and disease types.
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Infecciones Estafilocócicas/genética , Staphylococcus aureus/genética , Staphylococcus aureus/aislamiento & purificación , Virulencia/genética , Factores de Edad , Niño , Preescolar , China/epidemiología , Femenino , Genotipo , Humanos , Lactante , Recién Nacido , Masculino , Infecciones Estafilocócicas/epidemiologíaRESUMEN
BACKGROUND: Total and differential white blood cell counts are important for the diagnostic evaluation of suspected diseases. To facilitate the interpretation of total and differential white blood cell counts in pediatric patients, the present study investigated age-dependent changes in total and differential white blood cell counts in healthy reference children. METHODS: Data were obtained from the Pediatric Reference Intervals in China study (PRINCE), which aims to establish and verify pediatric reference intervals for Chinese children based on a nationwide multicenter cross-sectional study from January 2017 to December 2018. Quantile curves were calculated using the generalized additive models for location, shape, and scale method. The 2.5th, 50th, and 97.5th quantile curves were calculated for both total and differential white blood counts. Percents of stacked area charts were used to demonstrate the proportions of differential white blood cells. All statistical analyses were performed using R software. RESULTS: Both 50th and 97.5th quantiles of total white blood cell count and monocyte count were highest at birth, then rapidly decreased in the first 6 months of life; relatively slow reduction continued until 2 years of age. The lymphocyte count was low during infancy and increased to its highest level at 6 months of age; it then exhibited moderate and continuous reduction until approximately 9 years of age. The pattern of neutrophil count changed with age in a manner opposite to that of lymphocyte count. Besides, there were two inter-sections of lymphocyte count and neutrophil count during infancy and at approximately 5 years of age, based on locally weighted regression (LOESS) analysis. There were no apparent age-related changes in eosinophil or basophil counts. CONCLUSION: These data regarding age-related changes in total and differential white blood cell counts can be used to assess the health of pediatric patients and guide clinical decisions.
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Neutrófilos , Niño , China , Estudios Transversales , Humanos , Recién Nacido , Recuento de Leucocitos , Recuento de Linfocitos , Valores de ReferenciaRESUMEN
BACKGROUND: COVID-19 reported in pregnant women has occured in late pregnancy, while there are no reports of infection in the first and second trimester. We report two neonates born to mothers with COVID-19 during the second trimester. CASE PRESENTATION: Two pregnant women had symptomatic COVID-19 in the second trimester. Throat swabs at delivery for SARS-COV-2 RNA were negative for both women and their newborns. The first woman had positive serum IgM and IgG antibodies to SARS-COV-2 before delivery. Her newborn had negative IgM antibody to SARS-COV-2 but IgG was positive on the 7th day after birth. The second woman had negative serum IgM antibody to SARS-COV-2 but IgG was positive before delivery. Her newborn had negative serum IgM antibody to SARS-COV-2 but IgG was positive at 48 h after birth. None of the neonates developed clinical symptoms of COVID-19. CONCLUSION: SARS-COV-2 is unlikely to be vertically transmitted in utero as evidenced by the specific antibodies in the serum of the two women and their newborns. The two women with SARS-COV-2 infection in the second trimester did not develop serious complications at delivery and outcomes of the neonates were good.
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Infecciones por Coronavirus/transmisión , Transmisión Vertical de Enfermedad Infecciosa , Neumonía Viral/transmisión , Complicaciones Infecciosas del Embarazo/virología , Adulto , Betacoronavirus/aislamiento & purificación , COVID-19 , Infecciones por Coronavirus/sangre , Femenino , Humanos , Inmunoglobulina M/sangre , Recién Nacido , Madres , Pandemias , Neumonía Viral/sangre , Embarazo , Complicaciones Infecciosas del Embarazo/sangre , Segundo Trimestre del Embarazo , SARS-CoV-2RESUMEN
BACKGROUND: Bloodstream infections (BSI) caused by carbapenem-resistant K. pneumoniae (CRKP) are associated with high rates of morbidity and mortality. Early identification of patients at highest risk is very important. The aim of this study was to describe the clinical characteristics and mortality of K. pneumoniae BSI and to identify risk factors associated with CRKP BSI among paediatric patients. METHODS: From January 2011 to December 2014, a retrospective case-control study was conducted at Beijing Children's Hospital, China. Risk factors for CRKP BSI and for K. pneumoniae BSI-related death were evaluated. Patients with BSI caused by K. pneumoniae were identified from the microbiology laboratory database. Data regarding demographic, microbiological and clinical characteristics, therapy and outcome were collected from the medical records. RESULTS: A total of 138 patients with K. pneumoniae BSI were enrolled, including 54 patients with CRKP BSI and 84 patients with carbapenem-susceptible K. pneumoniae (CSKP) BSI. Most of the BSI (114; 82.6%) were healthcare-associated, while the rest (24; 17.4%) were community-acquired. Hematologic malignancies (odds ratio (OR):4.712, [95% CI: 2.181-10.180], P < 0.001) and previous cephalosporin administration (OR: 3.427, [95% CI: 1.513-7.766], P = 0.003) were found to be associated with the development of CRKP BSI. 28-day mortality of K. pneumoniae BSI was 8.7%. Mechanical ventilation (OR:9.502, [95% CI: 2.098-43.033], P = 0.003), septic shock (OR:6.418, [95% CI: 1.342-30.686], P = 0.020), and isolation of CRKP (OR:9.171, [95% CI: 1.546-54.416], P = 0.015) were independent risk factors for 28-day mortality of K. pneumoniae BSI. CONCLUSION: Hematologic malignancies and previous cephalosporin administration were associated with the development of CRKP BSI, while mechanical ventilation, septic shock and CRKP infection were independent mortality predictors for K. pneumoniae BSI. More attention should be paid to CRKP BSI in the paediatric population.
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Antibacterianos/uso terapéutico , Bacteriemia/epidemiología , Carbapenémicos/uso terapéutico , Farmacorresistencia Bacteriana Múltiple , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/aislamiento & purificación , Adolescente , Bacteriemia/diagnóstico , Bacteriemia/tratamiento farmacológico , Bacteriemia/mortalidad , Estudios de Casos y Controles , Niño , Mortalidad del Niño , Preescolar , China/epidemiología , Femenino , Humanos , Lactante , Recién Nacido , Infecciones por Klebsiella/diagnóstico , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/mortalidad , Masculino , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Análisis de SupervivenciaRESUMEN
AIM: The aim of this study was to evaluate the clinical features and characteristics of drug resistance in newly diagnosed pediatric tuberculosis (TB) patients in northern China. METHODS: Mycobacterium tuberculosis isolates were collected from September 2010 to October 2016 at the Beijing Children's Hospital. Patients were divided into two groups (resistant to at least one drug and pan-susceptible) according to drug susceptibility testing (DST) results. RESULTS: A total of 132 new cases, mainly from northern China (87.9%), were included in the study. The median age was 1.9 years (1 month-15 years). Resistance to at least one drug was detected in Mycobacterium tuberculosis isolates from 33 (25%) cases. Eight cases of multidrug-resistant TB (MDR-TB) (6.1%) were detected. The two groups did not differ in clinical presentations (disease site, fever >2 weeks, and cough >2 weeks) or in chest imaging (lesion location, lymphadenitis [mediastinal], and pleural effusion). CONCLUSIONS: The rate of Mycobacterium tuberculosis drug resistance in new pediatric TB cases was as high as in the new adult patients surveyed in the national drug resistance survey conducted in 2007. No significant difference was observed in clinical features between patients infected with drug-resistant and drug-susceptible strains. Routine DST is important for prescribing effective antituberculosis treatment regimens.
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Farmacorresistencia Bacteriana Múltiple/fisiología , Tuberculosis Extensivamente Resistente a Drogas/fisiopatología , Mycobacterium tuberculosis/aislamiento & purificación , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Tuberculosis Resistente a Múltiples Medicamentos/fisiopatología , Adolescente , Antituberculosos/farmacología , Niño , Preescolar , China , Tuberculosis Extensivamente Resistente a Drogas/tratamiento farmacológico , Tuberculosis Extensivamente Resistente a Drogas/microbiología , Femenino , Genotipo , Humanos , Lactante , Recién Nacido , Masculino , Pruebas de Sensibilidad Microbiana/métodos , Mycobacterium tuberculosis/efectos de los fármacos , Estudios Retrospectivos , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológicoRESUMEN
OBJECTIVE: To characterize carbapenem (CPM)-non-susceptible Klebsiella pneumoniae (K. pneumoniae) and carbape-nemase produced by these strains isolated from Beijing Children's Hospital based on a five-year surveillance. METHODS: The Minimal Inhibition Concentration values for 15 antibiotics were assessed using the Phonix100 compact system. PCR amplification and DNA sequencing were used to detect genes encoding carbapenemases. WHONET 5.6 was finally used for resistance analysis. RESULTS: In total, 179 strains of CPM-non-susceptible K. pneumoniae were isolated from January, 2010 to December, 2014. The rates of non-susceptible to imipenem and meropenem were 95.0% and 95.6%, respectively. In the 179 strains, 95 (53.1%) strains carried the blaIMP gene, and IMP-4 and IMP-8 were detected in 92 (96.8%) and 3 (3.2%) IMP-producing isolates, respectively. 65 (36.3%) strains carried the blaNDM-1 gene. 6 (3.4%) strains carried the blaKPC gene, and KPC-2 were detected in 6 KPC-producing isolates. In addition, New Delhi-Metallo-1 (NDM-1) producing isolates increased from 7.1% to 63.0% in five years and IMP-4 producing isolates decreased from 75.0% to 28.3%. CONCLUSION: High frequencies of multiple resistances to antibiotics were observed in the CPM-non-susceptible K. pneumoniae strains isolated from Beijing Children's Hospital. The production of IMP-4 and NDM-1 metallo-ß-lactamases appears to be an important mechanism for CPM-non- susceptible in K. pneumoniae.
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Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica/fisiología , Regulación Enzimológica de la Expresión Génica/fisiología , Hospitales Pediátricos , Klebsiella pneumoniae/enzimología , beta-Lactamasas/metabolismo , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Niño , China/epidemiología , Resistencia a Medicamentos , Humanos , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , Pruebas de Sensibilidad Microbiana , Vigilancia de la Población , Factores de Tiempo , beta-Lactamasas/genéticaRESUMEN
AIM: To evaluate the efficacy of percutaneous vertebroplasty (PVP) combined with interventional tumor removal (ITR) in providing pain relief, reducing disability, and improving functional performance in patients with malignant vertebral compression fractures without epidural involvement. METHODS: Patients with malignant vertebral compression fractures (n=58) were treated with either PVP+ITR (n=31, group A) or PVP alone (n=27, group B). A 14 G needle was inserted into the vertebral body, and the tract was sequentially dilated with working cannulae. When the last working cannula had reached the distal pedicle of vertebral arch, ITR was performed with a marrow nucleus rongeurs inserted through the working cannula. Finally, cement was injected into the excavated vertebral body. Patients were followed up at 1, 3, and 6 months after the procedure, and every 6 months thereafter. RESULTS: The overall excellent and good pain relief rate during follow-ups was significantly better in group A than in group B (94% vs.56%; p=0.002). The average VAS, ODI, and KPS scores at 3 months, 6 months, 1-year, and >1 year were all significantly lower in group A than in group B (p<0.05). The mean cement filling volume and the stability of the treated vertebrae were significantly higher in group A than in group B (p<0.05). CONCLUSIONS: The combination of PVP+ITR is a safe and effective procedure, capable of providing significantly greater pain relief and vertebral stability than PVP alone in patients with malignant vertebral compression fractures.
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Mesenchymal stem cells have been widely studied to promote local bone regeneration of osteonecrosis of the femoral head (ONFH). Previous studies observed that dimethyloxaloylglycine (DMOG) enhanced the angiogenic and osteogenic activity of mesenchymal stem cells by activating the expression of hypoxia inducible factor-1α (HIF-1α), thereby improving the bone repair capacity of mesenchymal stem cells. In the present study, it was investigated whether DMOG could increase the bone repair capacity of adipose-derived stem cells (ASCs) in the treatment of ONFH. Western blot analysis was performed to detect HIF-1α protein expression in ASCs treated with different concentrations of DMOG. The results showed DMOG enhanced HIF-1α expression in ASCs in a dose-dependent manner at least for 7 days. Furthermore, DMOG-treated ASCs were transplanted into the necrotic area of a rabbit model of ONFH to treat the disease. Four weeks later, micro-computed tomography (CT) quantitative analysis showed that 58.8±7.4% of the necrotic area was regenerated in the DMOG-treated ASCs transplantation group, 45.5±3.4% in normal ASCs transplantation group, 25.2±2.8% in only core decompression group and 10.6±2.6% in the untreated group. Histological analysis showed that transplantation of DMOG-treated ASCs clearly improved the bone regeneration of the necrotic area compared with the other three groups. Micro-CT and immunohistochemical analysis demonstrated the revasculation of the necrotic area were also increased significantly in the DMOG-treated ASC group compared with the control groups. Thus, it is hypothesized that DMOG could increase the bone repair capacity of ASCs through enhancing HIF-1α expression in the treatment of ONFH.
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Although tuberculosis (TB) has been the greatest killer due to a single infectious disease, pediatric TB is still hard to diagnose because of the lack of sensitive biomarkers. Metabolomics is increasingly being applied in infectious diseases. But little is known regarding metabolic biomarkers in children with TB. A combination of a NMR-based plasma metabolic method and classification and regression tree (CART) analysis was used to provide a broader range of applications in TB diagnosis in our study. Plasma samples obtained from 28 active TB children and 37 non-TB controls (including 21 RTIs and 16 healthy children) were analyzed by an orthogonal partial least-squares discriminant analysis (OPLS-DA) model, and 17 metabolites were identified that can separate children with TB from non-TB controls. CART analysis was then used to choose 3 of the markers, l-valine, pyruvic acid, and betaine, with the least error. The sensitivity, specificity, and area under the curve (AUC) of the 3 metabolites is 85.7% (24/28, 95% CI, 66.4%, 95.3%), 94.6% (35/37, 95% CI, 80.5%, 99.1%), and 0.984(95% CI, 0.917, 1.000), respectively. The 3 metabolites demonstrated sensitivity of 82.4% (14/17, 95% CI, 55.8%, 95.3%) and specificity of 83.9% (26/31, 95% CI, 65.5%, 93.9%), respectively, in 48 blinded subjects in an independent cohort. Taken together, the novel plasma metabolites are potentially useful for diagnosis of pediatric TB and would provide insights into the disease mechanism.
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Tuberculosis/diagnóstico , Betaína/análisis , Biomarcadores/sangre , Estudios de Casos y Controles , Niño , Análisis Discriminante , Humanos , Espectroscopía de Resonancia Magnética , Metaboloma , Metabolómica/métodos , Plasma/metabolismo , Ácido Pirúvico/análisis , Sensibilidad y Especificidad , Valina/análisisRESUMEN
BACKGROUND: The present study was undertaken to investigate the clinical characteristics of hemolytic uremic syndrome (HUS) secondary to cobalamin C disorder (cbl-C disorder). METHODS: We reviewed retrospectively the medical records of 3 children with HUS secondary to cbl-C disorder who had been treated between April 1, 2009 and October 31, 2013. RESULTS: The 3 patients with HUS secondary to cbl-C disorder presented with progressive hemolytic anemia, acute renal failure, thrombocytopenia, poor feeding, and failure to thrive. Two of the 3 patients once had high blood pressure. The mutations of c.609G>A (p.W203X), c.217C>T (p.R73X) and c.365A>T (p.H122L) in the methylmalonic aciduria (cobalamin deficiency) cbl-C type, with homocystinuria gene were detected in the 3 patients. In these patients the levels of lactate dehydrogenase and homocysteine in serum were elevated and the level of methylmalonic acid (MMA) in urine was also elevated. After treatment with hydroxocobalamin, 2 patients were discharged with no obvious abnormal growth and neurological development and 1 patient died of multiple organ failure. CONCLUSIONS: The results of this study demonstrated that cbl-C disorder should be investigated in any child presenting with HUS. The high concentrations of homocysteine and MMA could be used for timely recognization of the disease. Once the high levels of plasma homocystein and/or plasma or urine MMA are detected, the treatment with parenteral hydroxocobalamin should be prescribed immediately. The early diagnosis and treatment would contribute to the good prognosis of the disease.
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Proteínas Portadoras/genética , Síndrome Hemolítico-Urémico/genética , Síndrome Hemolítico-Urémico/terapia , Deficiencia de Vitamina B 12/genética , Vitamina B 12/uso terapéutico , Preescolar , China , Femenino , Estudios de Seguimiento , Predisposición Genética a la Enfermedad , Síndrome Hemolítico-Urémico/etiología , Síndrome Hemolítico-Urémico/fisiopatología , Homocisteína/metabolismo , Humanos , Lactante , Masculino , Mutación , Oxidorreductasas , Enfermedades Raras , Estudios Retrospectivos , Medición de Riesgo , Muestreo , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Deficiencia de Vitamina B 12/complicaciones , Deficiencia de Vitamina B 12/tratamiento farmacológicoRESUMEN
In order to achieve the rapid identification of fire resistive coating for steel structure of different brands in circulating, a new method for the fast discrimination of varieties of fire resistive coating for steel structure by means of near infrared spectroscopy was proposed. The raster scanning near infrared spectroscopy instrument and near infrared diffuse reflectance spectroscopy were applied to collect the spectral curve of different brands of fire resistive coating for steel structure and the spectral data were preprocessed with standard normal variate transformation(standard normal variate transformation, SNV) and Norris second derivative. The principal component analysis (principal component analysis, PCA)was used to near infrared spectra for cluster analysis. The analysis results showed that the cumulate reliabilities of PC1 to PC5 were 99. 791%. The 3-dimentional plot was drawn with the scores of PC1, PC2 and PC3 X 10, which appeared to provide the best clustering of the varieties of fire resistive coating for steel structure. A total of 150 fire resistive coating samples were divided into calibration set and validation set randomly, the calibration set had 125 samples with 25 samples of each variety, and the validation set had 25 samples with 5 samples of each variety. According to the principal component scores of unknown samples, Mahalanobis distance values between each variety and unknown samples were calculated to realize the discrimination of different varieties. The qualitative analysis model for external verification of unknown samples is a 10% recognition ration. The results demonstrated that this identification method can be used as a rapid, accurate method to identify the classification of fire resistive coating for steel structure and provide technical reference for market regulation.
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The available data on the epidemic of drug resistant tuberculosis (TB) among children in China is limited. This study attempted to clarify the drug resistance profiles of clinical strains isolated from children and estimate risk factors related to acquisition of drug resistance. All Mycobacterium tuberculosis strains from children (age <15 years) and adolescent (age 15-18 years) TB patients received in the strain library of Chinese Center for Disease Control and Prevention between January 2005 and December 2012 were included in the study. A study collection included 450 clinical isolates (100 from children, 159 from adolescents, and 191 from adults) from all over China. Drug susceptibility testing was performed by a proportion method. As a result, the drug resistance and multi-drug resistance (MDR) rates in children were 55% (55/100) and 22% (22/100), respectively. In children with MDR-TB, new cases accounted for 40.9% (9/22). Compared with adults, the drug resistance rates were similar in all subgroups (new cases, previously treated cases and all cases) of children (P > 0.05), except for the lower resistance rate to isoniazid in total cases of children (P = 0.011). Patient related information was included in the MDR-TB association analysis. The treatment history was found to be strongly associated with MDR-TB in all three age groups (P < 0.05). Our results demonstrate that the prevalence of drug resistant TB in children in China is alarmingly high and similar to that seen in adults. In contrast, in adolescents, the drug resistance rate to most tested drugs was lower than in adults. Primary transmission and inadequate treatment are two equally important factors for the high MDR-TB rate in children. Thus, major efforts in the TB control in children should focus on decreasing the transmission of drug resistant TB and early testing of drug resistance.
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Farmacorresistencia Bacteriana Múltiple , Mycobacterium tuberculosis/patogenicidad , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología , Adolescente , Adulto , Distribución por Edad , Factores de Edad , Antituberculosos/uso terapéutico , Niño , China/epidemiología , Encuestas Epidemiológicas , Humanos , Pruebas de Sensibilidad Microbiana , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/aislamiento & purificación , Prevalencia , Factores de Riesgo , Tuberculosis Resistente a Múltiples Medicamentos/diagnóstico , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Tuberculosis Resistente a Múltiples Medicamentos/transmisiónRESUMEN
Thermal preparation of lysozyme-imprinted microspheres was firstly investigated by using biocompatible ionic liquid (IL) as a thermal stabilizer. The imprinted microspheres made with IL could obtain the good recognition ability to template protein, whereas the imprinted polymer synthesized in the absence of it had a similar adsorption capacity to the non-imprinted one. Furthermore, the preparation conditions of imprinted polymers (MIPs) including the content of IL, temperature of polymerization, and types of functional monomers and crosslinkers were systematically analyzed via circular dichroism spectrum and activity assay. The results illustrated that using hydroxyethyl acrylate as the functional monomer, ethylene glycol dimethacrylate as the crosslinker, 5 % IL as the stabilizer, and 75 °C as the reaction temperature could retain the structure of template protein as much as possible. The obtained MIPs showed excellent recognition ability to the template protein with the separation factor and selectivity factor value of 4.30 and 2.21, respectively. Consequently, it is an effective way to accurately imprint and separate template protein by cooperatively using circular dichroism spectroscopy and activity assay during the preparation of protein MIPs. The method of utilizing IL to stabilizing protein at high temperature would offer a good opportunity for various technologies to improve the development of macromolecules imprinting.
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Líquidos Iónicos , Microesferas , Impresión Molecular , Muramidasa/química , Muramidasa/metabolismo , Animales , Pollos , Dicroismo Circular , Polímeros , Extracción en Fase Sólida , TemperaturaRESUMEN
One of the big challenges in tissue engineering for treating large bone defects is to promote the angiogenesis of the tissue-engineered bone. Hypoxia inducible factor-1α (HIF-1α) plays an important role in angiogenesis-osteogenesis coupling during bone regeneration, and can activate a broad array of angiogenic factors. Dimethyloxaloylglycine (DMOG) can activate HIF-1α expression in cells at normal oxygen tension. In this study, we explored the effect of DMOG on the angiogenic activity of bone mesenchymal stem cells (BMSCs) in the tissue-engineered bone. The effect of different concentrations of DMOG on HIF-1a expression in BMSCs was detected with western blotting, and the mRNA expression and secretion of related angiogenic factors in DMOG-treated BMSCs were respectively analyzed using qRT-PCR and enzyme linked immunosorbent assay. The tissue-engineered bone constructed with ß-tricalcium phosphate (ß-TCP) and DMOG-treated BMSCs were implanted into the critical-sized calvarial defects to test the effectiveness of DMOG in improving the angiogenic activity of BMSCs in the tissue-engineered bone. The results showed DMOG significantly enhanced the mRNA expression and secretion of related angiogenic factors in BMSCs by activating the expression of HIF-1α. More newly formed blood vessels were observed in the group treated with ß-TCP and DMOG-treated BMSCs than in other groups. And there were also more bone regeneration in the group treated with ß-TCP and DMOG-treated BMSCs. Therefore, we believed DMOG could enhance the angiogenic activity of BMSCs by activating the expression of HIF-1α, thereby improve the angiogenesis of the tissue-engineered bone and its bone healing capacity.
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Aminoácidos Dicarboxílicos/farmacología , Células Madre Mesenquimatosas/efectos de los fármacos , Neovascularización Fisiológica/efectos de los fármacos , Ingeniería de Tejidos/métodos , Animales , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/fisiología , Ratas Endogámicas F344 , Cráneo/trasplanteRESUMEN
OBJECTIVE: To study the plasmid-mediated AmpC ß-lactamases and the genotypes of Escherichia coli and Klebsiella spp. in children. METHODS: Escherichia coli and Klebsiella spp. of strains were isolated at our division from January to December 2009. Cefoxitin disk diffusion method was used to screen Escherichia coli and Klebsiella spp. for phenotypic AmpC enzyme. Multiple PCR method was adopted to test the genotypes of AmpC enzyme-positive Escherichia coli and Klebsiella spp.strains. RESULTS: Of all Escherichia coli and Klebsiella spp., 65 were insensitive to cefoxitin disk and 17 strains carried DHA type AmpC gene. The prevalence of plasmid-mediated AmpC enzyme in Escherichia coli and Klebsiella spp. was 26.2% (17/65). Among plasmid-mediated AmpC enzyme isolates, 14 (38.9%) Klebsiella pneumoniae strains, 2 (7.7%) Escherichia coli strains and 1 (33.3%) Klebsiella oxytoca strains carried the DHA-1 AmpC gene. The genes of MOX, CIT, DHA, ACC, MIR and FOX were not found in other 48 strains. CONCLUSIONS: The identified plasmid-mediated AmpC genes are all of DHA-1 genotype in Escherichia coli and Klebsiella spp. The prevalence of plasmid-mediated AmpC enzyme in Klebsiella pneumoniae isolates is relatively high in children.
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Proteínas Bacterianas/genética , Escherichia coli/enzimología , Klebsiella pneumoniae/enzimología , beta-Lactamasas/genética , Proteínas Bacterianas/aislamiento & purificación , Niño , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Genotipo , Humanos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Plásmidos , Reacción en Cadena de la Polimerasa/métodos , beta-Lactamasas/aislamiento & purificaciónRESUMEN
OBJECTIVE: To study the distribution and correlation of trace elements in peripheral blood of children in Beijing so as to offer scientific evidence for the supplementation of trace elements and to prevent lead intoxication. METHODS: Contents of trace elements in whole blood of 13 929 children in Beijing region were detected by Atomic Absorption Spectrometer. According to developmental condition, children were divided into young infancy group, infancy group, toddler's age group, preschool age group, school age group and adolescence group. Every group was divided into males and females. Distribution and correlation of trace elements in different age groups and in different sex sets were then analyzed and compared. RESULTS: The level of copper, calcium and magnesium were stable in different age groups and in different sex sets. There were no obvious significant differences in age groups and sex sets and there were no deficiency of copper, calcium and magnesium discovered. The level of zinc increased gradually following the growth of age and the level of zinc was (81.71 +/- 15.91) micromol/L. There were significant differences in different age groups noticed as well in sex sets of infancy group, toddler's age group and preschool age group. The rate of deficiency of zinc decreased gradually following the growth of age. The rate of zinc deficiency was 13.7% and there were obvious differences noticed in sex sets of toddler, preschool and school age groups. The level of iron increased gradually following the growth of age with the level of iron as (8.28 +/- 0.78) mmol/L. There were significant differences noticed in different age groups, after infancy stage. There was significant difference noticed also in sex sets after school age group. The rate of iron deficiency decreased obviously following the growth of age. The iron deficiency rate was 12.9%, and significantly different in sex sets of young infancy, school age and adolescence groups. The level of lead increased gradually following the growth of age, with the overall level as (59.97 +/- 26.52) microg/L; There was an obvious significant differences noticed in different age groups with significant differences noticed in sex sets after toddler's age group. The rate of lead intoxication increased gradually following the growth of age. The rate of lead intoxication was 8.2%. There were significant differences noticed in sex sets after toddler's age group. However, there were negative correlations noticed among the levels of lead and copper, zinc, calcium, magnesium and iron. There were no correlations between the level of calcium and iron found but showed positive correlation among other trace elements. CONCLUSION: The deficiency of calcium was basically corrected but the deficiency of zinc and iron were still obvious. There was a high level of lead noticed in these children. It is important to advocate on healthy feeding program, on culture good hygienic habit and on away from the lead pollution sites.