Synthesis of Holmium-Oxide Nanoparticles for Near-Infrared Imaging and Dye-Photodegradation.

The development of multifunctional nanomaterials has received growing research interest, thanks to its ability to combine multiple properties for severing highly demanding purposes. In this work, holmium oxide nanoparticles are synthesized and characterized by various tools including XRD, XPS, and TEM. These nanoparticles are found to emit near-infrared fluorescence (800-1100 nm) under a 785 nm excitation source. Imaging of the animal tissues was demonstrated, and the maximum imaging depth was found to be 2.2 cm. The synthesized nanoparticles also show the capability of facilitating dye (fluorescein sodium salt and rhodamine 6G) degradation under white light irradiation. The synthesized holmium oxide nanoparticles are envisioned to be useful for near-infrared tissue imaging and dye-degradation.

Real-time artificial intelligence for endoscopic diagnosis of early esophageal squamous cell cancer (with video).

BACKGROUND AND AIMS: Endoscopic diagnosis of early esophageal squamous cell cancer (ESCC) is complicated and dependent on operators' experience. This study aimed to develop an artificial intelligence (AI) model for automatic diagnosis of early ESCC. METHODS: Non-magnifying and magnifying endoscopic images of normal/noncancerous lesions, early ESCC, and advanced esophageal cancer (AEC) were retrospectively obtained from Qilu Hospital of Shandong University. A total of 10,988 images from 5075 cases were chosen for training and validation. Another 2309 images from 1055 cases were collected for testing. One hundred and four real-time videos were also collected to evaluate the diagnostic performance of the AI model. The diagnostic performance of the AI model was compared with endoscopists by magnifying images and the assistant efficiency of the AI model for novices was evaluated. RESULTS: The AI diagnosis for non-magnifying images showed a per-patient accuracy, sensitivity, and specificity of 99.5%, 100%, 99.5% for white light imaging, and 97.0%, 97.2%, 96.4% for optical enhancement/iodine straining images. Regarding diagnosis for magnifying images, the per-patient accuracy, sensitivity, and specificity were 88.1%, 90.9%, and 85.0%. The diagnostic accuracy of the AI model was similar to experts (84.5%, P = 0.205) and superior to novices (68.5%, P = 0.005). The diagnostic performance of novices was significantly improved by AI assistance. When it comes to the diagnosis for real-time videos, the AI model showed acceptable performance as well. CONCLUSIONS: The AI model could accurately recognize early ESCC among noncancerous mucosa and AEC. It could be a potential assistant for endoscopists, especially for novices.

Impact of a real-time automatic quality control system on colorectal polyp and adenoma detection: a prospective randomized controlled study (with videos).

BACKGROUND AND AIMS: Quality control can decrease variations in the performance of colonoscopists and improve the effectiveness of colonoscopy to prevent colorectal cancers. Unfortunately, routine quality control is difficult to carry out because a practical method is lacking. The aim of this study was to develop an automatic quality control system (AQCS) and assess whether it could improve polyp and adenoma detection in clinical practice. METHODS: First, we developed AQCS based on deep convolutional neural network models for timing of the withdrawal phase, supervising withdrawal stability, evaluating bowel preparation, and detecting colorectal polyps. Next, consecutive patients were prospectively randomized to undergo routine colonoscopies with or without the assistance of AQCS. The primary outcome of the study was the adenoma detection rate (ADR) in the AQCS and control groups. RESULTS: A total of 659 patients were enrolled and randomized. A total of 308 and 315 patients were analyzed in the AQCS and control groups, respectively. AQCS significantly increased the ADR (0.289 vs 0.165, P < .001) and the mean number of adenomas per procedure (0.367 vs 0.178, P < .001) compared with the control group. A significant increase was also observed in the polyp detection rate (0.383 vs 0.254, P = .001) and the mean number of polyps detected per procedure (0.575 vs 0.305, P < .001). In addition, the withdrawal time (7.03 minutes vs 5.68 minutes, P < .001) and adequate bowel preparation rate (87.34% vs 80.63%, P = .023) were superior for the AQCS group. CONCLUSIONS: AQCS could effectively improve the performance of colonoscopists during the withdrawal phase and significantly increase polyp and adenoma detection. (Clinical trial registration number: NCT03622281.).

Low expression of microRNA-340 confers adverse clinical outcome in patients with acute myeloid leukemia.

MicroRNA-340 (miR-340) was considered as a tumor suppressor by affecting cancer cell proliferation, apoptosis, invasion, and migration, and was downregulated in diverse cancers. Moreover, dysregulation of miR-340 was also found to be associated with drug resistance and predicted patients' survival in various cancers. Herein, we investigated miR-340 expression and its clinical significance in acute myeloid leukemia (AML). Real-time quantitative polymerase chain reaction was performed to detect miR-340 expression in bone marrow (BM) from 99 newly diagnosed AML patients except for acute promyelocytic leukemia (APL), 19 AML patients achieved complete remission (CR), and 29 healthy donors. BM miR-340 expression was significantly underexpressed in newly diagnosed AML patients as compared with controls (p = 0.031) and AML patients achieved CR (p = 0.025). No significant differences were observed between miR-340 expression and most of the clinicopathologic features (p > 0.05). However, low miR-340 expression was found to be associated with lower CR rate in both non-APL-AML and cytogenetically normal AML (CN-AML; p = 0.001 and 0.031, respectively), and acted as an independent risk factor for CR by logistic regression analysis (p = 0.001 and 0.021, respectively). More important, among both non-APL-AML and CN-AML, low expression of miR-340 was also associated with shorter overall survival (OS; p = 0.013 and 0.005, respectively), and was further validated by Cox regression (p = 0.031 and 0.039, respectively). Collectively, our study showed that BM miR-340 expression was downregulated in AML, and low expression of miR-340 correlated with adverse prognosis.

Detection of human bocavirus in nasopharyngeal aspirates versus in broncho-alveolar lavage fluids in children with lower respiratory tract infections.

To compare the presence of human bocavirus (HBoV) in nasopharyngeal aspirates (NPA) versus broncho-alveolar lavage fluids (BAL) in children with lower respiratory tract infections (LRTIs), as revealed by real-time PCR, in order to confirm the diagnostic validity of NPA samples. A retrospective 5-year study was performed from 2009 to 2014 in 1,194 patients under the age of 17 years (mean age of 3 years) that were diagnosed with LRTIs and from whom both NPA and BAL were obtained. Clinical and demographic data were recorded, and NPA and BAL samples were analyzed for HBoV-positivity by real-time PCR. Of the 1,194 patients enrolled, 65 (5.4%) patients had HBoV detected from NPA, and 61 (5.1%) had HBoV detected from BAL. For HBoV, there was a significant association between the NPA and BAL samples (P < 0.001), but the diagnostic validity was relatively low (kappa = 0.414). When real-time PCR-positivity for HBoV in BAL was used as a reference for diagnosis, NPA had a good specificity and better positive predictive validity in male patients or those younger than 3 years of age. NPA has a similar yield and a good specificity for diagnosis of LRTIs with HBoV compared to BAL. The best diagnostic validity for NPA was detected in male patients or those younger than 3 years old.

[An epidemiological study on human rhinovirus C in hospitalized children with respiratory tract infections].

OBJECTIVE: To investigate the detection rates, epidemical characteristics, and clinical features of human rhinovirus C (HRV-C) in hospitalized children with respiratory tract infections (RTIs) in Suzhou, China. METHODS: A total of 1 702 hospitalized children with RTIs from January to December, 2014 were enrolled, and 1 702 nasopharyngeal aspirate samples were collected from all children. RT-PCR was used to measure HRV mRNA, and quantitative real-time PCR combined with high-resolution melting curve was used to measure HRV-C. RESULTS: Of all children, 244 (14.34%) were detected to have HRV infection, among whom 69 (69/244, 28.3%) had HRV-C infection. The rate of mixed infection of HRV-C with other viruses and bacteria was 61% (42/69). HRV-C was detected in each month of the year, and the detection rate of HRV-C in autumn was significantly higher than that in spring, summer, and winter (P<0.05). The children aged 2-5 years had a significantly higher detection rate of HRV-C than those in the other age groups (P<0.05). Compared with HRV-A/B infection, HRV-C infection led to significantly higher proportions of patients with lobar pneumonia and acute exacerbation of asthma (P<0.05), as well as patients with increased neutrophil count and CRP level (P<0.05). There were no significant differences in sex distribution or other clinical manifestations (P>0.05). CONCLUSIONS: HRV-C infection accounts for about 1/3 of HRV infection, with a high incidence rate in autumn. The rate of mixed infection of HRV-C with other viruses and bacteria is high, and children aged 2-5 years have the highest detection rate of HRV-C. Children with HRV-C infection have similar clinical manifestations as those with HRV-A/B infection.

[Association of T lymphocyte subsets and allergens with Mycoplasma pneumoniae infection complicated by wheezing in infants and young children].

OBJECTIVE: To investigate the percentage of T lymphocyte subsets and allergen screening results in infants and young children with Mycoplasma pneumoniae (MP) infection complicated by wheezing. METHODS: Flow cytometry was used to measure the percentage of peripheral blood T cell subsets in 354 infants and young children with MP infection complicated by wheezing (MP wheezing group), 336 infants and young children with MP infection but without wheezing (MP non-wheezing group), and 277 children with recurrent wheezing (recurrent wheezing group). Allergen screening was also performed for these children. RESULTS: Both the MP wheezing group and recurrent wheezing group had significantly lower percentages of CD3+ and CD3+CD8+ lymphocytes than the MP non-wheezing group (p<0.05). The MP groups with or without wheezing had a significantly higher percentage of CD3+CD4+ lymphocytes than the recurrent wheezing group (p<0.05). Both the MP wheezing group and recurrent wheezing group had significantly higher percentages of CD3-CD19+ and CD19+CD23+ lymphocytes than the MP non-wheezing group (p<0.05), and the recurrent wheezing group had the highest percentages (p<0.05). The overall positive rate of food allergens was significantly higher than that of inhaled allergens (30.3% vs 14.7%; p<0.05). The positive rates of food and inhaled allergens in the recurrent wheezing group and MP wheezing group were significantly higher than in the MP non-wheezing group (p<0.05), and the recurrent wheezing group had the highest rates. CONCLUSIONS: Imbalance of T lymphocyte subsets and allergic constitution play important roles in the pathogenesis of MP infection complicated by wheezing in infants and young children.

The Down-Regulation of MicroRNA-497 Contributes to Cell Growth and Cisplatin Resistance Through PI3K/Akt Pathway in Osteosarcoma.

BACKGROUND: Down-expression of microRNA-497 (miR-497) was often found in malignancies. The purposes of this study were to determine the expression of miR-497 in human osteosarcoma and to establish the association between miR-497 expression with cell survival and the sensitivity to cisplatin in human osteosarcoma cells. METHODS: The effects of ectopic miR-497 expression on the cell survival and cisplatin sensitivity in osteosarcoma cells were measured by the Cell Counting Kit-8 (CCK-8) assay. Quantitative real-time PCR (qRT-PCR) was utilized to determine the expression of miR-497. The effects of ectopic miR-497 expression on the expression of VEGFA, Akt and p-Akt were determined by western blot. RESULTS: Real-time quantitative PCR analysis revealed that miR-497 was significantly down-regulated in osteosarcoma tissues and in the osteosarcoma cell line SAOS-2 compared with adjacent nontumorous osteosarcoma tissues and normal human osteoblasts. Up-regulation of miR-497 inhibited cell survival and enhanced the sensitivity to cisplatin in osteosarcoma cells. In addition, knockdown of miR-497 induced osteosarcoma cells growth and cisplatin resistance. Luciferase reporter assay and western blot confirmed that VEGFA was a direct target of miR-497. PI3K inhibitor LY294002 abrogated miR-497 inhibitors induced cisplatin resistance. CONCLUSION: Taken together, our results suggest that miR-497 modulates the sensitivity to cisplatin at least in part through PI3K/Akt pathway in osteosarcoma cells.

miR-664 negatively regulates PLP2 and promotes cell proliferation and invasion in T-cell acute lymphoblastic leukaemia.

MicroRNAs (miRNAs) play important roles in the pathogenesis of many types of cancers by negatively regulating gene expression at posttranscriptional level. However, the role of microRNAs in leukaemia, particularly T-cell acute lymphoblastic leukaemia (T-ALL), has remained elusive. Here, we identified miR-664 and its predicted target gene PLP2 were differentially expressed in T-ALL using bioinformatics methods. In T-ALL cell lines, CCK-8 proliferation assay indicated that the cell proliferation was promoted by miR-664, while miR-664 inhibitor could significantly inhibited the proliferation. Moreover, migration and invasion assay showed that overexpression of miR-664 could significantly promoted the migration and invasion of T-ALL cells, whereas miR-664 inhibitor could reduce cell migration and invasion. luciferase assays confirmed that miR-664 directly bound to the 3'untranslated region of PLP2, and western blotting showed that miR-664 suppressed the expression of PLP2 at the protein levels. This study indicated that miR-664 negatively regulates PLP2 and promotes proliferation and invasion of T-ALL cell lines. Thus, miR-664 may represent a potential therapeutic target for T-ALL intervention.

[Clinical significance of MP-DNA from endotracheal aspirates in diagnosis of Mycoplasma pneumoniae pneumonia in children].

OBJECTIVE: To compare the detection rates of Mycoplasma pneumoniae (MP) from nasopharyngeal aspirates (NPA) and bronchoalveolar lavage fluid (BALF) in children with pneumonia. METHODS: A total of 164 hospitalized children with pneumonia were enrolled. NPA and BALF of these children were collected within 24 hours of admission, and MP-DNA was detected by fluorescence quantitative PCR. Venous blood samples of all these children were collected within 24 hours of admission and on days 7-10 of treatment, and serum MP-IgM was detected using ELISA. RESULTS: The positive rate of MP-DNA in NAP of the 164 cases was 51.8% , which was lower than 63.4% as the detection rate of MP-IgM in serum (P=0.044), and the two detection rates were moderately consistent with each other (Kappa=0.618, P<0.01). The positive rate of MP in BALF was 71.3%, which was not significantly different with that of MP-IgM in serum (P>0.05), and the detection rates were well consistent (Kappa=0.793, P<0.01). The detection rate of MP in NPA was lower than that in BALF (P<0.01), with moderate consistency between two of them (Kappa=0.529, P<0.01). The median MP copy number in BALF was significantly higher than that in NPA (P<0.01). The MP detection rates in NPA and BALF were significantly different among different courses of disease (P<0.05). As the course of disease extended, the MP detection rates in both NPA and BALF showed a declining trend; children with MP pneumonia of 1-2 weeks' duration and 2-4 weeks' duration had a higher MP-DNA detection rate in BALF than in NPA (P<0.05). CONCLUSIONS: MP-DNA in BALF has a high sensitivity, with a great significance for early diagnosis of MP pneumonia, while NPA MP-DNA tests may lead to a missed diagnosis.

Etiology of acute bronchiolitis and the relationship with meteorological conditions in hospitalized infants in China.

BACKGROUND/PURPOSE: To investigate the prevalence of common viruses and Mycoplasma pneumoniae (MP) in hospitalized infants with acute bronchiolitis and study the relationship between bronchiolitis and meteorological conditions. METHODS: A 2-year prospective study was conducted on infants with a first episode of bronchiolitis admitted to Respiratory Department of Suzhou Children's Hospital. Demographic and clinical characteristics and meteorological conditions were obtained and analyzed. RESULTS: Pathogens were identified in 59.6% of 998 cases analyzed. The most frequent pathogen identified was respiratory syncytial virus (28.7%), followed by human bocavirus (11.6%), MP (9.0%), human parainfluenza virus-3 (7.8%), human metapneumovirus (6.6%), influenza A (3.5%), adenovirus (1.0%), and human parainfluenza virus-1 (0.3%). The clinical scores in children with MP or human metapneumovirus single infections, based on the assessment of severity of acute bronchiolitis, were significantly lower than in children with respiratory syncytial virus single infections. Respiratory syncytial virus had the strongest inverse correlation with mean temperature, followed by influenza A and human metapneumovirus. In addition, MP and human parainfluenza virus-3 showed positive correlations with mean temperature. CONCLUSION: Although respiratory syncytial virus was the most frequent pathogen in patients in whom bronchiolitis was diagnosed, other pathogens, including newly identified viruses and MP, also play important roles in infants with bronchiolitis. Different respiratory pathogens have different traits in response to certain meteorological conditions.

[Clinical and experimental studies of childhood acute myeloid leukemia with 11q23/MLL rearrangements].

OBJECTIVE: To explore clinical and experimental features of 28 cases of childhood acute myeloid leukemia (AML) with 11q23/MLL gene rearrangements. METHODS: Karyotypes of 234 cases of de novo childhood AML were analyzed using short-term culture of bone marrow cells and R-banding. The fusion transcripts involving MLL gene and partial tandem duplication of MLL (MLL-PTD) were detected by multiple reverse transcription polymerase chain reaction (RT-PCR) assay. Two cases with 11q23 translocation by karyotypic analysis but with negative result of multiple RT-PCR were studied with MLL-dual-color fluorescence in situ hybridization (D-FISH). RESULTS: R-banding karyotypic analysis has revealed 20 cases with 11q23 translocation (14 cases with M5, 4 cases with M4, 2 cases with M2), including 12 cases with t(9;11)(p22;q23), 3 cases with t(1;11)(q21;q23), 2 cases with t(6;11)(q27;q23), 1 case with t(11;19)(q23;p13), 1 with t(5;11)(q31;q23), and 1 with t(X;11)(q24;q23). Eighteen cases with 11q23 translocation having fusion transcripts involving MLL genes were confirmed with multiple RT-PCR; 2 cases showed negative results, but they were confirmed to have MLL rearrangements by D-FISH. MLL-PTD was also detected in 8 cases (4 cases M5, 2 cases M4, M2 and M6, one case each) from the other childhood AML cases. The total incidence of 11q23/MLL gene rearrangements was 11.97% (28/234), and most of patients(85.7%, 24/28) were M4/M5. The complete remission (CR) rate after treatment for the 28 cases with MLL rearrangements was 53.8%, the difference was significant by statistics (P< 0.05) compared with 90.5% for the control group (M4/M5 childhood AML with other karyotypic abnormalities or normal karyotype). Of them, 2 cases receiving intensive chemotherapy survived for 81 and 66 months, respectively, 4 cases receiving allogeneic stem cell transplantation survived for 21, 20, 16 and 11 months, respectively, and are still alive with CR. The medium survival (MS) time for 28 cases with 11q23/MLL rearrangements was 11 months, whereas the MS for control group was 15 months. The difference was not statistically significant(P> 0.05). CONCLUSION: The 11q23/MLL rearrangements is highly correlated with the occurrence of monocytic leukemia (M4 and M5). The 11q23 translocation and MLL-PTD are mutually exclusive, though both are indicative of poor prognosis. Intensive chemotherapy and allogeneic stem cell transplantation may ameliorate the clinical outcome. Multiple RT-PCR combined with karyotypic analysis and D-FISH are useful for screening the 11q23/MLL rearrangements in childhood AML.

[Enhanced Autophagy Suppresses Proplatelet Formation in Pediatric Immune Thrombocytopenia].

OBJECTIVE: To investigate the effect of enhanced autophagy in megakaryocyte to proplatelet formation in children with immune thrombocytopenia(ITP). METHODS: Giemsa staining and immunofluorescence staining were used to observe megakaryocyte morphology and proplatelet formation, Western blot was used to determine the expression of cytoskeleton protein and autophagy related protein. Autophagr regulation drugs Rap or 3-MA was used to regulate autophagy of megakaryocytes. RESULTS: Some vacuole-like structures was found in ITP megakaryocytes of the children, the expression of LC3II/I (ITP 1.32±0.18； Ctrl 0.49±0.16，P<0.05) and Atg5-Atg12 (ITP 0.69±0.17； Ctrl 0.12±0.08，P<0.05) was significantly higher in ITP children as compared with those in control group. The immu- nofluorescence staining showed that the cytoskeleton arrangement in megakaryocytes of ITP children was abnormal, and the phosphorylation of myosin light chain was also increased(ITP 0.74±0.09, Ctrl 0.05±0.02，P<0.05). In vitro, inducer or inhibitor of autophagy could regulate the production of proplatelet and the expression of cell cycle related protein, including CyclinD1（Veh 1.08±0.12; Rap 0.46±0.04; Rap+3-MA 0.70±0.03）, CyclinD2（Veh 0.47±0.04; Rap 0.27±0.04; Rap+3-MA 0.41±0.03）, P21（Veh 0.15±0.01; Rap 0.04±0.01; Rap+3-MA 0.05±0.01）. CONCLUSION: Enhanced autophagy is the key factor of poor proplatelet formation in megakaryocytes of ITP children.

[Viral pathogens of acute respiratory infection in hospitalized children from Suzhou].

OBJECTIVE: To investigate the viral pathogens of acute respiratory infection (ARI) in hospitalized children from Suzhou of China. METHODS: The nasopharyngeal aspirate samples were obtained from 1,668 hospitalized children with ARI. Common respiratory viruses, including respiratory syncytial virus (RSV), influenza virus A and B, parainfluenza viruses 1, 2 and 3 and adenovirus, were detected using direct immunofluorescence. Human metapneumovirus (hMPV) gene fragments were detected by RT-PCR. RESULTS: Viral agents were identified in 597 cases (35.8%). RSV was the most frequent (17.6%). RSV infection is more common in children less than 1 year old. A highest detection rate of RSV was found during winter and spring. hMPV was detected in 10.6% of the cases, with a peak detection rate between March and May. Single viral infection was found in 561 cases (33.6%) and mixed viral infection in 36 cases (including 27 cases at age of less than 1 year). RSV and hMPV co-infection was common (n=22). CONCLUSIONS: RSV is common pathogen of ARI in children from Suzhou. RSV viral activity peaks during winter and spring. The children at age of less than 1 year are susceptible to RSV. hMPV is also an important pathogen of ARI, with a peak detection rate between March and May. Mixed viral infection is common in children less than 1 year old.

miR-590 promotes cell proliferation and invasion in T-cell acute lymphoblastic leukaemia by inhibiting RB1.

MicroRNAs play important roles in the pathogenesis of cancers by inhibiting gene expression at posttranscriptional level. Here, we identified that miR-590 and its predicted target gene RB1 are differentially expressed in T-cell acute lymphoblastic leukaemia (T-ALL). The correlation between miR-590 and RB1 was further confirmed in 395 T-ALL patients. In T-ALL cell lines, miR-590 promoted the cell proliferation by increasing G1/S transition. Moreover, migration and invasion assay showed that miR-590 promotes the migration and invasion of T-ALL cells by increasing E-cadherin and inhibiting MMP-9. Luciferase assays confirmed that miR-590 directly binds to the 3'untranslated region of RB1, and western blotting showed that miR-590 suppresses the expression of RB1 at the protein levels. This study indicated that miR-590 inhibits RB1 and promotes proliferation and invasion of T-ALL cells. Thus, miR-590 may represent a potential therapeutic target for T-ALL intervention.

Temporal characteristics of respiratory syncytial virus infection in children and its correlation with climatic factors at a public pediatric hospital in Suzhou.

BACKGROUND: Respiratory syncytial virus (RSV) is the most important viral pathogen in infants and children. It is important to analyze RSV epidemic patterns and related relevant factors in order to prevent further infections and related complications. OBJECTIVE: To explore the relationship between RSV infection rate in hospitalized children from Suzhou area and climatic factors. STUDY DESIGN: 42,664 nasopharyngeal specimens from hospitalized children with acute respiratory infections were screened for RSV antigens using direct immunofluorescence. 472 RSV positive samples were randomly selected and performed real-time PCR to identify RSV subtype. Monthly meteorological data in Suzhou area was collected (average temperature, relative humidity, precipitation, total sunshine, and average wind speed) from 2001 to 2011. The relation between RSV infections and climatic factors was evaluated using correlation and stepwise regression analyses. RESULTS: The annual RSV infection rate in hospitalized children in Suzhou from 2001 to 2011 varied between 11.85% and 27.30%. The highest monthly infection rates occurred from November to April. The time interval from November to April was considered the infection season. Seasonal RSV infection rates from 2001 to 2010 were 40.75%, 22.72%, 39.93%, 27.37%, 42.71%, 21.28%, 38.57%, 19.86%, and 29.73%. The infection rate of any season was statistically different from the next season. There was no significant difference in RSV infection rates in the 2010-2011 and 2009-2010 epidemic seasons. Among the 472 randomly selected RSV positive samples, 412 were found to be RSV subtype A (RSV-A), while 60 subtype B (RSV-B). The monthly RSV infection rate was negatively correlated with monthly average temperature (r=-0.84), total sunshine (r=-0.47), precipitation (r=-0.31), relative humidity (r=-0.20), and average wind speed (r=-0.20), (P<0.05). Stepwise regression analysis showed monthly average temperature fit into a linear model (R(2)=0.64, P<0.01) with a regression coefficient of -1.52 (t=15.21, P<0.01). CONCLUSIONS: RSV infection in Suzhou occurred most frequently between November and April. The number of infections peaked every other year. Abnormally high infection rate in non-epidemic season only caused by RSV-A. Ambient temperature played an important role in the development of RSV infection.

[Significance of interplay between Rap1 and cadherin to the development of myelodysplastic syndrome].

OBJECTIVE: To explore the hematopoietic pathophysiology of myelodysplastic syndrome (MDS) at stem/progenitor cell level by analyzing the gene expression profiles associated with hematopoiesis. METHODS: The differentially expressed genes which were involved in the hematopoiesis were screened by microarray using CD34(+) cells from MDS patients firstly. RQ-PCR was then applied to validate the screened genes using CD34(+) cells from MDS-RA patients who had normal karyotype. The linkages with hematopoiesis among these validated genes were analyzed. RESULTS: Among the differentially expressed genes in CD34(+) cells of MDS-RA patients, Rap1GAP was up-regulated significantly (P < 0.01). Cadherins, which can interplay with Rap1, including N-cadherin and E-cadherin, were down-regulated significantly (P < 0.01). ß-catenin, a downstream effector of cadherins, was highly expressed in MDS-RA patients (P < 0.01). c-myc binding protein was down-regulated (P < 0.01), and c-myc promoter binding protein was up-regulated (P < 0.01). Rac1, Rac2 and Cdc42, which belong to RhoGTPases family and are associated with the cell morphology and hematopoiesis, were all expressed highly in MDS-RA patients (P < 0.01). CONCLUSION: The abnormal expression of cadherin, ß-catenin and c-myc associated genes were closely related to the dysplastic hematopoiesis of MDS. The down regulation of cadherin was associated with the positive feedback mechanism between Rap1 and cadherin. The aberrant expression of Rac1, Rac2 and Cdc42 may contribute to the morphological dysplasia of MDS.

[Clinical and laboratory features of pediatric acute myeloid leukemia with inversion of chromosome 16].

OBJECTIVE: To evaluate the clinical and laboratory features of pediatric inv(16) acute myeloid leukemia (AML) retrospectively. METHOD: Dual color fluorescence in situ hybridization (D-FISH) using a LSI CBFß inv(16) break apart probe labeled by Spectrum red and Spectrum green was performed in 15 acute myeloid leukemia cases, including 13 cases with or without abnormal eosinophils but with positive core binding factor ß (CBFß)-MYH11 fusion transcript detected by RT-PCR, and 2 cases with trisomy 8 (+8). The results were compared with the morphology, immunophenotype, karyotype and RT-PCR. RESULT: Morphologically, 12 cases were diagnosed as M(4)EO, 2 as M(4), and 1 as M(2a). Immunophenotypically, all 13 AML cases with inv(16) showed positive expression of CD(13) and CD(33), but without the expression of any lymphoid lineage antigens. Karyotyping analysis with G-banding detected inv(16) in 10 AML cases, including 9 M(4)EO cases and 1 M(2a), but only 5 positive cases were detected using R-banding technique. Among them, 2 cases had simultaneous +8 and trisomy22 (+22), one had +22 only in addition to inv(16). D-FISH revealed a CBFß-MYH11 rearrangement in 13 cases of AML with positive RT-PCR results, and the mean positive rate of cell detection was 55.15% (range 37.0% - 86.0%). The complete remission rate (CR) and median survival period in this series of inv(16) AML were 81.5%and 11 months, respectively, of whom, 8 cases were still in CR. Relapse and karyotypic evolution were seen in case 5 with +8, +22 in addition to inv(16). CONCLUSION: AML with inv(16) is a special subtype. Most cases belong to M(4)EO. Its prognosis is good in general, but it seems to be an unfavorable feature for AML with inv(16) and +8, +22 simultaneously, especially with karyotypic evolution. For detection of inv(16), G-banding technique is evidently superior to R-banding technique. D-FISH combined with RT-PCR are more sensitive and reliable than chromosome banding analysis.