[Association of lifestyle and apolipoprotein E gene with risk for cognitive frailty in elderly population in China]

Objective: To investigate the impact of lifestyle, apolipoprotein E (ApoE) gene, and their interaction on the risk for cognitive frailty in the elderly population in China. Methods: The study participants were from the Chinese Longitudinal Healthy Longevity Survey. The information about their lifestyles were collected by questionnaire survey, and a weighted lifestyle score was constructed based on β coefficients associated with specific lifestyles to assess the combined lifestyle. ApoE genotypes were assessed by rs429358 and rs7412 single nucleotide polymorphisms. Cognitive frailty was assessed based on cognitive function and physical frailty. Cox proportional hazards regression model was used to analyze the association of lifestyle and ApoE gene with the risk for cognitive frailty and evaluate the multiplicative and additive interactions between lifestyle and ApoE gene. Results: A total of 5 676 elderly persons, with median age [M (Q1, Q3)] of 76 (68, 85) years, were included, in whom 615 had cognitive frailty. The analysis by Cox proportional hazards regression model indicated that moderate and high levels of dietary diversity could reduce the risk for cognitive frailty by 18% [hazard ratio (HR)=0.82, 95%CI: 0.68-1.00] and 28% (HR=0.72, 95%CI: 0.57-0.91), respectively; moderate and high levels of physical activity could reduce the risk by 31% (HR=0.69, 95%CI: 0.56-0.85) and 23% (HR=0.77, 95%CI: 0.64-0.93), respectively. Healthy lifestyle was associated with a 40% reduced risk for cognitive frailty (HR=0.60, 95%CI: 0.46-0.78). ApoE ε4 allele was associated with a 26% increased risk for cognitive frailty (HR=1.26, 95%CI: 1.02-1.56). No multiplicative or additive interactions were found between lifestyle and ApoE gene. Conclusions: Dietary diversity and regular physical activity have protective effects against cognitive frailty in elderly population. Healthy lifestyle can reduce the risk for cognitive frailty in elderly population regardless of ApoE ε4 allele carriage status.

[Association of sleep duration and risk of frailty among the elderly over 80 years old in China: a prospective cohort study]

Objective: To explore the association between sleep duration and the risk of frailty among the elderly over 80 years old in China. Methods: Using the data from five surveys of the China Elderly Health Influencing Factors Follow-up Survey (CLHLS) (2005, 2008-2009, 2011-2012, 2014, and 2017-2018), 7 024 elderly people aged 80 years and above were selected as the study subjects. Questionnaires and physical examinations were used to collect information on sleep time, general demographic characteristics, functional status, physical signs, and illness. The frailty state was evaluated based on a frailty index that included 39 variables. The Cox proportional risk regression model was used to analyze the correlation between sleep time and the risk of frailty occurrence. A restricted cubic spline function was used to analyze the dose-response relationship between sleep time and the risk of frailty occurrence. The likelihood ratio test was used to analyze the interaction between age, gender, sleep quality, cognitive impairment, and sleep duration. Results: The age M (Q₁, Q₃) of 7 024 subjects was 87 (82, 92) years old, with a total of 3 435 (48.9%) patients experiencing frailty. The results of restricted cubic spline function analysis showed that there was an approximate U-shaped relationship between sleep time and the risk of frailty. When sleep time was 6.5-8.5 hours, the elderly had the lowest risk of frailty; Multivariate Cox proportional risk regression model analysis showed that compared to 6.5-8.5 hours of sleep, long sleep duration (>8.5 hours) increased the risk of frailty by 13% (HR: 1.13; 95%CI: 1.04-1.22). Conclusion: There is a nonlinear association between sleep time and the risk of frailty in the elderly.

Clinical characteristics, antimicrobial resistance, and risk factors for mortality in paediatric invasive pneumococcal disease in Beijing, 2012-2017

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.

[Response differences of radial growth of Larix gmelinii and Pinus sylvestris var. mongolica to climate change in Daxing'an Mountains, Northeast China]

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.

Age-dependent changes of total and differential white blood cell counts in children

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.

A dinuclear Eu(III) complex in the crystal structure of dodecaaqua-bis(μ2-4-(1H-tetrazol-5-yl)benzoato-κ2 O:O′) bis(5-(4-carboxylatophenyl)tetrazol-1-ide) tetrahydrate, C32H50Eu2N16O24

C32H50Eu2N16O24, monoclinic, P21/c (no. 14), a = 7.685(5) Å, b = 13.482(5) Å, c = 23.240(5) Å, β = 93.578(5)°, V = 2403.2(19) Å3, Z = 2, R gt(F) = 0.0235, wR ref(F 2) = 0.0577, T = 293 K.

Risk factors for carbapenem-resistant K. pneumoniae bloodstream infection and predictors of mortality in Chinese paediatric patients

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.

Clinical and Drug Resistance Characteristics of New Pediatric Tuberculosis Cases in Northern China

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.

Comparison of percutaneous vertebroplasty with and without interventional tumor removal for spinal metastatic tumor without epidural involvement

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.

Dimethyloxaloylglycine increases bone repair capacity of adipose-derived stem cells in the treatment of osteonecrosis of the femoral head

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.

Utility of Novel Plasma Metabolic Markers in the Diagnosis of Pediatric Tuberculosis: A Classification and Regression Tree Analysis Approach

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.

[The application of Hoffmann method in the establishment of children's reference intervals of erythrocyte count]

OBJECTIVE

To verify the reliability and feasibility of Hoffmann method in establishing pediatric reference intervals (RI) of erythrocyte count.

METHODS

Three hundreds and ninty-two thousands of hospital-based data for erythrocyte count of children aged in 1 to 17, measured by the Sysmex Xs-800i, was collected from Beijing Children's Hospital during January to December 2014. Outliers were removed using the Dixon method, then Hoffmann method was conducted to establish the gender and age stratified pediatric RIs of erythrocyte count. The erythrocyte count of 2 217 healthy children, recruited from Beijing Children's Hospital and Liaocheng Children's Hospital in Shandong province, was conducted as normal reference to verify the reliability of Hoffmann method in establishing RIs and to compare with existing RIs.

RESULTS

In 4 subgroups as following, male aging 1 to 12 years, male aging 13 to 17 years, female aging 1 to 12 years, female aging 13 to 17 years, the RIs of erythrocyte count established using Hoffmann method were (4.1-5.4)×10(12)/L, (4.4-5.7)×10(12)/L, (4.0-5.3)×10(12)/L, (4.0-5.3)×10(12)/L, respectively. The verification results in 2 217 healthy children showed that the proportions of out of range in four subgroups were 6.17%, 8.81%, 6.22%, 7.78%, respectively.

CONCLUSION

Hoffmann method produce reliable RIs according with the actual situation in healthy children, which is also convenient and is worth popularizing in clinical practice.

Influence of adenosine on preservation of porcine pancreas in islet transplantation

Ischemia time during transplantation has greatly restricted the quality and utilization of grafts. To improve the quality of islet transplantation, adenosine was added into the University of Wisconsin (UW) pancreas perfusate to assess its effect on islet yield and function in porcine pancreas. Ten pancreata from donation after cardiac death pigs were obtained and randomly divided into two groups: control group (N = 5) with UW perfusion solution, and experimental group (N = 5) with adenosine-enriched UW perfusion solution. The yield and purity of the islet cells were counted after they were collected, purified, and stained with dithizone. Acridine orange/propidium iodide staining was applied to determine islet cell viability. Islet function was assessed by glucose stimulated insulin secretion assays, and released insulin was quantified by enzyme-linked immunosorbent assay. The metabolic substrates of the pancreas were analyzed by trace dialysis technology. We found that the addition of adenosine in UW perfusion solution significantly increased the yield, purity and viability of islet cells, as well as enhanced their insulin release. In addition, the levels of metabolic substrates, pyruvate and lactate, were significantly reduced. The addition of adenosine could effectively increase islet cell viability during mechanical perfusions, which may improve islet transplantation. This perfusion protocol may be clinically feasible, and should be considered in the clinical setting.

Identification of long non-coding RNA involved in osteogenic differentiation from mesenchymal stem cells using RNA-Seq data

The aim of this study was to identify long non-coding RNA (lncRNA) associated with osteogenic differentiation from mesenchymal stem cells (MSCs) using high-throughput RNA sequencing (RNA-Seq) data. RNA-Seq dataset was obtained from the European Bioinformatics Institute (accession No. PRJEB4496), including two replicates each for immortalized mesenchymal stem cells iMSC#3 cultured in growth medium (GM) and differentiation medium (DM) for 28 days. The clean reads were aligned to a hg19 reference genome by Tophat and assembled by Cufflinks to identify the known and novel transcripts. RPKM values were calculated to screen for differentially expressed RNA. Novel lncRNA were screened based on various filter criteria. Subsequently, the underlying function of novel lncRNAs were predicted by functional annotation by ERPIN, a co-expression network was constructed by WGCNA and the KEGG pathway enriched by KOBAS. A total of 3171 RNA differentially expressed between the DM and GM groups (2597 mRNA and 574 lncRNA) were identified. Among the 574 differentially expressed lncRNA, 357 were known and 217 were novel lncRNA. Furthermore, 32 novel lncRNA were found to be miRNA precursors (including miR-689, miR-640, miR-601, and miR-544). A total of 14,275 co-expression relationships and 217 co-expression networks were obtained between novel lncRNA and mRNA. The differentially expressed lncRNA and mRNA were enriched into 6 significant pathways, including those for cancer, ECM-receptor interaction, and focal adhesion. Therefore, novel lncRNAwere identified and their underlying function predicted, which may provide the basis for future analyses of the role of lncRNA in osteoblastic differentiation.

Thermal preparation of lysozyme-imprinted microspheres by using ionic liquid as a stabilizer

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.

Dimethyloxaloylglycine improves angiogenic activity of bone marrow stromal cells in the tissue-engineered bone

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 β-tricalcium phosphate (β-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 β-TCP and DMOG-treated BMSCs than in other groups. And there were also more bone regeneration in the group treated with β-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.

Prognosis of colorectal cancer with liver metastasis: value of a prognostic index

The objective of the present study was to explore the factors related to the prognosis of colorectal cancer (CRC) and to establish a prognostic model for the selection of patients who might benefit from hepatic resection for metastatic CRC. A total of 293 patients undergoing liver resection for metastatic CRC (172 males and 80 females ranging in age from 26 to 80 years) were selected and clinical, pathological and outcome data were examined in this retrospective study. The prognostic index (PI) of the patients was calculated on the basis of results of multivariate analysis. Patients were stratified into different groups, with survival curves projected according to PI. The 1-, 3-, and 5-year overall survival rates were 58.3, 26.4, and 11.3%, respectively. Univariate analysis indicated that degree of primary tumor differentiation, resection margin, preoperative carcinoembryonic antigen (CEA) level, number of liver metastases, and resection of liver metastases were associated with prognosis (P < 0.05). In multivariate analysis, the last three factors were found to be independent prognostic factors. The resection of liver metastases was a favorable factor. Patients were classified into three groups according to PI, which differed significantly in survival rate (P < 0.05). The individual survival rate was evaluated based on PI. Resection of hepatic colorectal metastases may produce long-term survival and cure. The proposed PI was easy to use, was highly predictive of patient outcome, and permitted categorization of patients into treatment groups.

[Establishment of method collecting peripheral blood hematopoietic stem/progenitor cells from infants]

The aim of this study was to explore a safe method collecting peripheral blood stem/progenitor cell (PBSPC) from the infants of body weight less than 20 kg by using the COBE Spectra Blood Cell Separator through Auto-PBSC procedure. After washing tube by normal saline, one unit of irradiated RBC was infused into the apheresis set. When the collection terminated, only the concentrated RBC in the apheresis set was returned to the infant. The peripheral mononuclear cells (PBMNCs) and CD34+ cells were counted, the cell viability was determined. The results showed that 13 PBSPC collections were carried out successfully from 7 infants of body weight<20 kg. The average count of MNCs was 4.44x10(8)/kg [(3.46-6.45)x10(8)/kg], the CD34+ count was 2.20x10(6)/kg [(1.34-3.79)x10(6)/kg] and the cell viability was 98.45% (97%-100%) respectively. The vital signs of all the infants went smoothly during collection of PBSPCs. In conclusion, with the aid of COBE Spectra blood cell separator and other measures, the collection of PBSPCs from infants of body weight<20 kg is safe and effective, the PBMNCs containing enough PBSPC can be harvested for transplantation.

Characterization of multidrug-resistant and metallo-beta-lactamase-producing Pseudomonas aeruginosa isolates from a paediatric clinic in China

BACKGROUND

In the present study, we characterized multidrug-resistant Pseudomonas aeruginosa (MDRP) clinical isolates from a paediatric facility and investigated the types and features of the metallo-beta-lactamases (MBLs) produced by carbapenem-resistant strains.

METHODS

Four hundred and ninety-eight strains of Pseudomonas aeruginosa were isolated from patients at Beijing Children's Hospital between January 2005 and December 2006. The minimal inhibition concentrations (MICs) of the strains for 13 antibiotics were measured. A combination of the E test and PCR amplification/DNA sequencing was used to define the carbapenem-resistant strains.

RESULTS

We found that 24.1% (120/498) of the isolates were MDRP. The frequencies of resistance to imipenem and meropenem were 34.2% and 35.8%, respectively, and the MIC50 and MIC90 values for the two antibiotics were identical at 4 microg/ml and 32 microg/ml, respectively. The detection rate for carbapenem resistance was 49.2% (59/120). Among the 59 carbapenem-resistant Pseudomonas aeruginosa strains, 39 (66.1%) were positive for the MBL genotype; 35 (89.7%) strains carried the bla(IMP) gene and 4 (10.3%) strains carried the bla(VIM) gene. Neither bla(SPM) nor bla(GIM) was amplified from any of the 59 isolates. DNA sequencing revealed that IMP-1 was present in 35 IMP-producing isolates and VIM-2 was detected in four VIM-producing isolates.

CONCLUSIONS

These MDRP isolates exhibited high frequencies of resistance to carbapenems among clinical isolates from a paediatric facility in Beijing, China. The production of MBL appears to be an important mechanism for carbapenem resistance in Pseudomonas aeruginosa.

[Frequency of ABO type IgM antibody in 276 infants younger than six months]

The aim of study was to explore the frequency of ABO type IgM antibody in infants younger than six months. 309 hospitalized infants younger than six months were selected at first and their EDTA K(3) anticoagulant blood samples were taken. All the infants were divided into five groups: neonates within 1 week as group I; neonates aged 8 to 14 days as group II; neonates aged 15 days to 1 month as group III; infants aged two to 3 months as group IV and infants aged 4 to 6 months as group V. The monocolonal anti-A, anti-B serums, A cells, B cells and O cells were utilized to carried out the blood typing with tube test. The results indicated that from 309 samples tested 33 AB type sample were excluded. Out of the remains of 276 samples, 29 of 46 samples in group I were positive and with the ABO type consistent rate 63% (29/46); 41 of 64 samples in group II were positive and with the ABO type consistent rate 64% (41/64); 47 of 74 samples in group III were positive and with the ABO type consistent rate 63% (47/74); 28 of 45 samples in group IV were positive and with the ABO type consistent rate 62% (28/45); 40 of 47 samples in group V were positive and with the ABO type consistent rate 85%. It is concluded that the ABO type IgM antibody appear in most infants younger than six months and these IgM antibodies may be regarded as the important evidence for ABO typing in infants.

[Study on the distribution and correlation of trace elements in whole blood of children in Beijing]

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.

[Transfer of erythromycin-resistance among strains and species of bacteria: plasmid conjugation method in enterococcal isolates]

OBJECTIVE

To study if the resistance to macrolide in Enterococcus can be transferred between strains, and species of the same and different genera.

METHODS

Agar dilution was used to screen 30 enterococcal isolates that were resistant to erythromycin. Conjugation was performed by filter mating method. The 30 donor bacteria included 13 strains of Enterococcus faecalis, 16 strains of E. faecium, and 1 strain of E. hirae. The recipient bacteria included 1 strain of E. faecalis sensitive to erythromycin and resistant to tetracycline, and 1 strain of Staphylococcus aureus with the MIC against erythromycin of 0.25 approximately 1 microg/ml. Polymerase chain reaction was used to test the existence of ermB gene and the tranposons Tn1545 and Tn917 in the enterococcal isolates before and after filter mating.

RESULTS

The transfer rate between different strains and species of the same genus were all 100%. The MIC(50) and MIC(90) against erythromycin of 13 conjugates were both 512 microg/ml, and Tn1545 and Tn917 were found in the ermB gene of 12 conjugates. 17 conjugates were obtained from 16 strains of donor E. faecium and 1 strain of E. hirae with the MIC(50) and MIC(90) both of 512 microg/ml. The ermB gene was found in 16 of the 17 conjugates, and 11 of the 16 conjugates showed the existence of Tn1545 and Tn917, Tn1545 existed in the ermB gene of 4 conjugates, and Tn917 existed in the ermB gene of 1 conjugate. 30 conjugates of Staphylococcus aureus were obtained by plasmid conjugation and transfer with a transfer rate of 100% and the MIC(50) and MIC(90) both of 512 microg/ml. The ermB gene was found in 28 of the 30 conjugates. Both Tn1545 and Tn917 were found in the ermB gene of 23 of the 28 conjugates, Tn1545 was found in the ermB gene of 4 conjugates, and Tn917 was found in the ermB gene of 1 conjugate.

CONCLUSION

The resistance to macrolide of Enterococcus, related with the existence of ermB gene and transposons Tn1545 and Tn917, can be transferred between strains and species of same and different genera.

Detection of Fetal Sex in the Peripheral Blood of Pregnant Women

OBJECTIVE

To choose the best method to examine fetal sex in maternal blood as early as possible and evaluate the quantitative change of fetal-free DNA in maternal plasma.

METHOD

One hundred and fifty pregnant women were studied at 5-9 completed weeks of gestation. Fetal cells were isolated using lymphocyte separation liquid and 3% gelatin. Furthermore, fluorescence in situ hybridization was used to examine the terminal of the Y chromosome. Nested polymerase chain reaction (PCR) and real-time fluorescence quantitative PCR (FQ-PCR) were used to amplify the SRY gene of the plasma DNA extracted from the same 150 samples of maternal blood. Sequential analysis was performed using FQ-PCR during the whole pregnancy on 32 pregnant women carrying male fetuses.

RESULTS

Using fluorescence in situ hybridization, we can find male fetal cells in maternal blood as early as the 49th day. We can also find free fetal DNA in maternal plasma as early as the 49th and the 42nd day of pregnancy using nested PCR and FQ-PCR. The amount of fetal DNA was increasing with the gestation week. The standard value of every gestation week was obtained by FQ-PCR.

CONCLUSION

FQ-PCR was the best method to detect fetal sex in early pregnancy. There is a principle of quantitative change of free fetal DNA in maternal plasma.

Methylation status of the fragile histidine triad and E-cadherin genes in plasma of cervical cancer patients

Recent evidence suggests that tumor cells may release DNA into the serum and plasma of afflicted cancer patients. However, no report existed regarding the methylation status of the fragile histidine triad (FHIT) and E-cadherin genes in plasma samples of cervical cancer patients. Methylation-specific PCR (MSP) was employed to examine CpG island methylation of the FHIT and E-cadherin genes in 151 pretreatment plasma samples and 30 tumor tissue samples from cervical cancer patients. MSP products were cloned and sequenced. CpG island methylation of the FHIT and E-cadherin genes was detected in 30.46% and 39.74% of plasma samples, respectively, and in 53.33% and 60.0% of tissue samples, respectively. The total concordance rate of methylation between plasma samples and tissue samples in FHIT gene was 80.00% and that in E-cadherin gene was 76.66%. At least one of the two methylated genes was detected in 56.29% of plasma samples and 76.7% of tissue samples. The presence of both methylated genes was detected in 13.9% of plasma samples and 36.67% of tissue samples. We found that the higher the clinical stage and histologic grade, the higher the rate of methylation in both genes in plasma samples. CpG island methylation of the FHIT and E-cadherin genes is present in plasma of cervical cancer patients. Using the two genes as markers simultaneously may allow clinicians to diagnose and evaluate the effect of treatment earlier and using fewer invasive procedures.

[Phylogenetic study of Artemia from China using RAPD and AFLP markers]

We have applied the techniques of RAPD (random amplified polymorphic DNA) and AFLP (amplified fragment length polymorphism) to the analysis of the relationships among Artemia species and strains. RAPD markers were successfully employed to detect diversity and genetic differentiation among four species of brine shrimp: A. franciscana, A. urmiana, A. sinica, and A. parthenogenetica. Seventy, ten-base synthetic oligonucleotides were used to amplify a total of 458 distinct fragments. DNA polymorphisms were found in all the species examined; The highest percentage of polymorphic bands found in A. parthenogenetica, was 28.8 per cent. There are significant differences between bisexual sibling species and parthenogenetic populations. A. parthenogenetica provided 94 specific molecular markers, while bisexual sibling species gave 27 specific molecular markers. A. sinica is a species distinct from the other Old World bisexual species. AFLP were used to analyze 15 Artemia species and strains for genetic diversity. They are extremely sensitive to even a small sequence variation and more polymorphism than RAPD. Using only 10 pairs of primer combinations, we detected 580 AFLP bands of which were polymerphic. The RAPD and AFLP techniques are powerful DNA fingerprinting methods for classification of Artemia species and strains.

Construction of a DNA library from chromosome 4 of rice (Oryza sativa) by microdissection

A simple method to create a chromosome-specific DNA library of rice, including microdissection, amplification, characterization and cloning, is described. Rice chromosome 4 from a metaphase cell has been isolated and amplified by the Linker Adapter PCR (LA-PCR). The PCR products were labeled as probes with DIG-11-dUTP using the random priming method. Southern blot analysis with rice genomic DNA and specific RFLP markers demonstrated that the PCR products were derived from rice chromosome 4. A large library comprising over 100,000 recombinant plasmid microclones from rice chromosome 4 was constructed. Colony hybridization showed that 58% of the clones contained single or low-copy sequences and 42% contained repetitive sequences. The size of inserts generated by PCR ranged from 140bp to 500bp. This method will facilitate cloning of the specific chromosome DNA markers and important genes of rice.

Estimation of skin target site acyclovir concentrations following controlled (trans)dermal drug delivery in topical and systemic treatment of cutaneous HSV-1 infections in hairless mice

The use of controlled transdermal delivery of acyclovir (ACV) in the treatment of cutaneous herpes simplex virus type 1 infections in hairless mice was investigated. Using an in vivo animal model (A. Gonsho, et al. Int. J. Pharm. 65:183-194 (1990)) made it possible to quantify both, the topical and the systemic antiviral efficacy of ACV transdermal patches as a function of the drug delivery rate of the patches. Drug delivery rates required to attain systemic efficacy were found to be higher than the rates required to attain the same magnitude of topical efficacy. The ACV concentrations in the basal cell layer of the epidermis for 50% topical efficacy and 50% systemic efficacy were estimated. The basal epidermis layer was considered to be the site of antiviral drug activity (skin target site). Systemic plasma levels were obtained from pharmacokinetic studies and were used to estimate the ACV concentration achieved systemically in the basal epidermis layer. A computational model for drug permeation across skin was employed to estimate the ACV concentration achieved topically in the basal epidermis layer. Equal topical and systemic efficacies were found to correspond to equal drug concentrations at the site of antiviral activity. The length of the effective diffusion pathway of drug molecules in the dermis prior to entering the blood circulation was assumed to be approximately equal to 1/20 of the anatomical dermis thickness because of dermis vascularization.

Quantitative evaluation of ethanol effects on diffusion and metabolism of beta-estradiol in hairless mouse skin

The influence of low levels of ethanol on the simultaneous diffusion and metabolism of beta-estradiol (E2 beta) in hairless mouse skin was quantitatively evaluated. A wide range of diffusion/metabolism experiments was conducted with full-thickness skin, stripped skin, and dermis at the various ethanol levels. The experiments were carried out in a two-chamber diffusion-cell system where ethanol was present in both the donor and the receiver chambers at equal concentrations. Analysis of the experimental data with several enzyme distribution models further showed that the best model was that for which the enzyme activity resided totally in the epidermis and near the basal layer of the epidermis. The ethanol effects were separated and quantified in terms of the diffusion and metabolism parameters. Aqueous ethanol, even at low concentrations (greater than or equal to 25%), was found to have two important effects on E2 beta transport: ethanol functions as an inhibitor of the enzymatic conversion of E2 beta to estrone (E1) in the viable epidermis, and ethanol is able to enhance the transport of permeants across the lipoidal pathway of the stratum corneum.