Diffraction gratings based on a multilayer silicon nitride waveguide with high upward efficiency and large effective length.

Diffraction gratings with high upward diffraction efficiency and large effective length are required for chip-scale light detection and ranging. We propose a diffraction grating based on a multilayer silicon nitride waveguide, which theoretically achieves an upward diffraction efficiency of 92%, a near-field effective length of 376 µm, and a far-field divergence angle of 0.105° at a wavelength of 850 nm. The diffraction grating has a high tolerance to process variations based on Monte Carlo analysis. When the conditions are ±5% layer thickness variation, ±50nm lithographic variation, and ±20nm wavelength drift, more than 71% of the grating samples have a diffraction efficiency higher than 80%, and 100% of the samples have an effective length larger than 200 µm (corresponding to a far-field divergence <0.2∘). Furthermore, the near-field effective length of the grating with an upward diffraction efficiency above 90% can be adjusted from hundreds of microns to centimeters by changing the etching layer thickness and the grating duty cycle. This diffraction grating has a potential application in optical sensing and imaging from visible to near-IR wavelengths.

Methylene Blue Exerts Anticonvulsant and Neuroprotective Effects on Self-Sustaining Status Epilepticus (SSSE) Induced by Prolonged Basolateral Amygdala Stimulation in Wistar Rats.

BACKGROUND This study was designed to investigate the potential anticonvulsant and neuroprotective effects of methylene blue (MB) on self-sustaining status epilepticus (SSSE) induced by prolonged basolateral amygdala stimulation (BLA) in Wistar rats. MATERIAL AND METHODS The rats were randomly divided into 4 groups: (1) the Control group (rats without any treatment); (2) the Sham group (rats received electrode implantation but without electrical stimulation); (3) the SSSE group (rats received electrode implantation and additional electrical stimulation); and (4) the SSSE+MB group (rats received 1 mg/kg MB intraperitoneal injection 5 min after SSSE). SSSE models were established by prolonged BLA stimulation. The severities of SSSE were assessed by the number of separate seizures and the accumulated time of seizures. The variations of malondialdehyde/glutathione (MDA/GSH) were assessed 24 h after the establishment of SSSE. Nissl staining was performed to detect the surviving neurons in hippocampal CA1 and CA3 regions, and Western blotting assays were used to detect Caspase-3 (CASP3), B cell lymphoma 2 (BCL2), and BCL2-associated X protein (BAX). RESULTS Compared with the SSSE group, treatment with MB (1) markedly reduced the number and accumulated time of seizure activities; (2) significantly attenuated the increase of MDA and the decrease of GSH hippocampal levels; (3) markedly improved the cell morphology and alleviated the neuronal loss in hippocampal CA1 and CA3 regions; (4) significantly attenuated the increase of CASP3 and BAX and the decrease of BCL2 hippocampal levels. CONCLUSIONS MB has a protective effect in the SSSE model and may be useful as an adjuvant for preventing or treating epilepsy in humans.

Loss of heterozygosity for chromosomes 16q in Wilms tumors predicts outcomes: A meta-analysis.

BACKGROUND: The research findings suggest that the prognosis of children with Wilms tumor (WT) is affected by various factors. Some scholars have indicated that loss of heterozygosity (LOH) on chromosome 16q is associated with a poor prognosis in patients with WT. AIM: To further elucidate this relationship, we conducted a meta-analysis. METHODS: This meta-analysis was registered in INPLASY (INPLASY2023100060). We systematically searched databases including Embase, PubMed, Web of Science, Cochrane, and Google Scholar up to May 31, 2020, for randomized trials reporting any intrapartum fetal surveillance approach. The meta-analysis was performed within a frequentist framework, and the quality and network inconsistency of trials were assessed. Odds ratios and 95%CIs were calculated to report the relationship between event-free survival and 16q LOH in patients with WT. RESULTS: Eleven cohort studies were included in this meta-analysis to estimate the relationship between event-free survival and 16q LOH in patients with WT (I2 = 25%, P < 0.001). As expected, 16q LOH can serve as an effective predictor of event-free survival in patients with WT (risk ratio = 1.95, 95%CI: 1.52-2.49, P < 0.001). CONCLUSION: In pediatric patients with WT, there exists a partial correlation between 16q LOH and an unfavorable treatment prognosis. Clinical detection of 16q chromosome LOH warrants increased attention to the patient's prognosis.

Application and progress of palliative therapy in advanced gastric carcinomas.

Gastric carcinomas have high morbidity and mortality. It produces no noticeable symptoms in the early stage while causing complex complications in its advanced stage, making treatment difficult. Palliative therapy aims to relieve the symptoms of cancer patients and focuses on improving their quality of life. At present, five palliative therapies for advanced gastric carcinomas are offered: resection, gastrojejunostomy, stenting, chemotherapy, and radiotherapy. In recent years, palliative therapy has been used in the clinical treatment of advanced gastric carcinomas and related complications because of its efficacy in gastric outlet obstruction and gastric bleeding. In the future, multimodal and interdisciplinary palliative therapies can be applied to control general symptoms to improve patients' condition, prolong their lifespan and improve their quality of life.

Long-term prognostic value of macrophage migration inhibitory factor in ST-segment elevation myocardial infarction patients with metabolic syndrome after percutaneous coronary intervention.

Metabolic syndrome (MetS) is a major risk factor for cardiovascular disease and negatively affecting the prognosis of patients with ST elevation myocardial infarction (STEMI). Macrophage migration inhibitory factor (MIF) is a multipotent cytokine involved in various cardiovascular and inflammatory diseases. In this prospective study, we investigate the value of MIF in the long-term prognosis of STEMI combined with MetS after emergency PCI. Circulating MIF levels were measured at admission, and major adverse cardiovascular and cerebrovascular events (MACCE) were monitored during the follow-up period of 4.9 (3.9-5.8) years. MACCE occurred in 92 patients (22.9%), which was significantly higher in MetS (69/255, 27.1%) than in the non-MS subgroup (23/146, 15.8%, P < 0.05). Patients with MetS developed MACCE had the highest admission MIF level. Kaplan-Meier survival analysis using the cutoff value of admission MIF (143 ng/ml) showed that patients with a higher MIF level had a greater incidence of MACCE than those with lower MIF levels in both the MetS (P < 0.0001) and non-MetS groups (P = 0.016). After adjustment for clinical variables, the value of MIF ≥ 143 ng/ml still had the predictive power for the MetS group [HR 9.56, 95% CI (5.397-16.944),P < 0.001]; nevertheless, it was not the case in the non-MetS group. Our findings indicated that MetS is a critical risk factor for adverse clinical outcomes in patients with STEMI, and a high admission MIF level has predictive power for the long-term MACCE, which is superior in STEMI patients with MetS and better than other traditional predictors.

[Coronary artery disease diagnosis with 64-slice spiral CT coronary artery angiography in China and abroad: a meta analysis].

OBJECTIVE: This meta-analysis evaluated the accuracy of diagnosing coronary artery disease using 64-section spiral computed tomography, and compared the difference between Chinese studies and abroad studies. METHODS: Relevant English and Chinese articles published from 1998 to 2009 were searched in Cochrane library, Medline, Embase database, OVID database and CNKI. Heterogeneity was tested, pooled weighted sensitivity and specificity and the corresponding 95%CI were calculated. Summary receiver operating characteristic (SROC) curve was drawn and the area under the curve was calculated, differences between studies from China and abroad were compared. RESULTS: A total of 433 articles were searched and 108 articles were included (46 English articles and 62 Chinese articles) after excluding articles of research purposes or design does not match. Because of no gold standard, no blind, can not be calculated literature data, 7 and 20 (P > 0.05), 44 and 6 (P < 0.05), 3 and 1 (P < 0.05) Chinese studies and English articles respectively were excluded. Twenty-seven articles fulfilled all inclusion criteria (8 Chinese and 19 foreign studies) In 8 Chinese studies the pooled weighted sensitivity and specificity and area under SROC curve was 0.892 (95%CI: 0.868 - 0.913), 0.972 (95%CI: 0.966 - 0.977) and 0.983 (95%CI: 0.966 - 1.000) at segment-based analysis. In 19 foreign studies, the pooled weighted sensitivity and specificity and area under SROC curve was 0.971(95%CI: 0.957 - 0.982), 0.878 (95%CI: 0.852 - 0.902) and 0.973 (95%CI: 0.958 - 0.989) at patient-based analysis, 0.917 (95%CI: 0.895 - 0.936), 0.919 (95%CI: 0.909 - 0.928) and 0.974 (95%CI: 0.964 - 0.984) at vessel-based analysis, 0.882 (95%CI: 0.868 - 0.895), 0.959 (95%CI: 0.956 - 0.962) and 0.985 (95%CI: 0.978 - 0.992) at segment-based analysis. Pooled weighted pecificity of 64-section spiral CT angiography at segment-based analysis has significant different between home and abroad (P < 0.05). CONCLUSIONS: Meta-analysis showed that noninvasive 64-section spiral computed tomography could correctly diagnose coronary artery disease with high sensitivity and specificity. Quality of related studies performed in abroad is significantly higher than those performed in China.

The correlation study on homocysteine, blood lipids and blood glucose levels in patients with cerebral infarction.

PURPOSE: To explore the correlation of changes in homocysteine (HCY) l, blood lipids and blood glucose levels in patients with cerebral infarction. METHODS: 120 patients with cerebral infarction admitted to our hospital from February 2018 to February 2020 were selected as the experimental group, and 120 healthy volunteers in the same period were selected as the control group. The blood pressure and the homocysteine, blood lipids, blood glucose levels were compared; the experimental group was subdivided into single cerebral infarction group, combined diabetes group and combined hypertension group, and their blood lipid levels were compared with the control group; Spearman method was used to analyze the relationship between HCY, blood lipid, blood sugar levels and cerebral infarction. RESULTS: ① The diastolic and systolic blood pressure levels of the experimental group were higher, whereas the control group were lower (P<0.05). ② The levels of total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and TC/[high density lipoprotein cholesterol (HDL-C)] of the experimental group were higher, but the level of HDL-C was lower than that of the control group (all P<0.05). ③ The fasting blood glucose (FBG) and glycosylated hemoglobin (GHb) levels of the experimental group were higher than those of the control group (all P<0.05). ④ The HCY level in the experimental group was higher than that in the control group (P<0.05). ⑤ The levels of TC, TG, LDL-C and TC/HDL-C in single cerebral infarction group, combined diabetes group and combined hypertension group were higher, and HDL-C level was lower than that in control group (all P<0.05). ⑥ Spearman analysis revealed that HCY was positively correlated with TC, TG, LDL-C and FBG (all P<0.05). CONCLUSION: The level of HCY is positively correlated with the levels of TC, TG, LDL-C and FBG in patients with cerebral infarction.

Robot-assisted versus stereotactic frame-based stereoelectroencephalography in medically refractory epilepsy.

AIM: To explore the difference between robot assisted (RA) and stereotactic frame based (SF) stereoelectroencephalography (SEEG) in patients with medically refractory epilepsy. METHODS: We undertook a retrospective review of 33 SEEG cases at our center, of which 14 were SF performed from March to October 2018 and 19 were RA performed from November 2018 to December 2019. Detailed review of medical histories and operative records as well as imaging and trajectory plans was carried out for each patient, and the results related to each technique compared. A multiple linear regression model was used to test for variables that significantly influenced placement error. RESULTS: Compared to the SF group, the RA group had a higher mean number of electrodes per patient (10.7 ±â€¯2.8 versus 6.4 ±â€¯0.8, P < 0.0001) and a significantly shorter mean operative time (127.3 ±â€¯40.7 versus 152.7 ±â€¯13.6 min, P = 0.033). For the RA group, the intracranial implantation length was positively correlated with target point error (p = 0.000), depth error (p = 0.043), and two-dimensional (2D) radial error (p = 0.041). Conversely, skull thickness was negatively correlated with the TP error (p = 0.004), depth error (p = 0.037) and 2D radial error (p = 0.000). We also analyzed the mean entry point, target point, depth and 2D radial errors, the complication rates, and the results of epileptogenic zone (EZ) localization and Engel class. The results showed no difference in these aspects between the SF group and the RA group. CONCLUSION: This study suggests that, compared to stereotactic frame based SEEG, robot assisted SEEG is significantly more efficient and comparable in safety and effectiveness.

Meta-analysis of quantitative diffusion-weighted MR imaging in the differential diagnosis of breast lesions.

BACKGROUND: To determine, in a meta-analysis, the diagnostic performance of quantitative diffusion-weighted (DW) MR imaging in patients with breast lesions. METHODS: English and Chinese studies published prior to June 2009 to assess the diagnostic performance of quantitative DWI in patients with breast lesions were reviewed and summarized with reference to the inclusion and exclusion criteria. Methodological quality was assessed by using the quality assessment of diagnostic studies (QUADAS) instrument. Publication bias analysis was performed by using Comprehensive Meta-analysis version 2. Meta-Disc version 1.4 was used to describe primary results and explore homogeneity by Chi-square test and inconsistency index; to explore threshold effect by receiver operator characteristic (ROC) space and Spearman correlation coefficient; and to pool weighted sensitivity and specificity by fixed or random effect model. A summary ROC (sROC) curve was constructed to calculate the area under the curve (AUC). RESULTS: Of 65 eligible studies, 13 with 615 malignant and 349 benign lesions were included in the original meta-analysis, among which heterogeneity arising from factors other than threshold effect and publication bias was explored. Methodological quality was moderate. The pooled weighted sensitivity and specificity with corresponding 95% confidence interval (CI) in one homogenous subgroup of studies using maximum b = 1000 s/mm2 were 0.84 (0.80, 0.87) and 0.84 (0.79, 0.88) respectively. AUC of sROC was 0.9085. Sensitivity analysis demonstrated that the pooled estimates were stable and reliable. CONCLUSIONS: Quantitative DWI has a higher specificity to differentiate between benign and malignant breast lesions compared to that of contrast-enhanced MRI. However, large scale randomized control trials (RCTs) are necessary to assess its clinical value because of disunified diffusion gradient factor b and diagnosis threshold.

Effects of gamma knife irradiation on the expression of NMDA receptor subunits in rat forebrain.

OBJECTIVE: To examine the effects of gamma knife surgery (GKS) on the expression of N-methel-D-asparate receptor (NMDAR) subunits in rat forebrain. MATERIALS AND METHODS: Using stereotactic technique, we performed gamma knife irradiation on the left forebrain of 13 male Wistar rats with a maximum dose of 60 Gy. These animals were raised for 24h, 30 and 60 days before they were killed. Then immunohistochemistry was applied to detect the relative levels of NMDAR subunits (NR1, NR2A, and NR2B) in the target region. RESULTS: The expression of NR1 and NR2A but not NR2B increased significantly in the cortex 30 and 60 days after irradiation. However, no significant differences in the expression of these three subunits were detected in the caudate putamen at all time points. CONCLUSION: gamma knife irradiation induced the upregulation of NMDAR subunits, NR1, and NR2A, which might represent a possible mechanism underlying the therapeutic effects of gamma knife irradiation on many neurological diseases, including drug resistance epilepsy.

[Clinical effect and safety of miconazole nitrate 1200 mg in treating vulvovaginal candidiasis].

OBJECTIVE: To investigate the clinical effect and safety of miconazole nitrate 1200 mg in treating vulvovaginal candidiasis (VVC). METHODS: An open, multicentre, non case control clinical trial was conducted in 568 patients suffering from VVC from Jul 1, 2006 to Nov 30, 2006. Routine examination, score of clinical symptoms and physical signs, mycetology test and safety evaluation were done in all patients before treatment, 7 - 14 days after treatment and 30 days after treatment. RESULTS: Seven to fourteen days after treatment, 563 patients could be followed and 323 patients (57.3%) were cured. The overall effective rate was 90.2%. The mycologic cure rate was 91.3% (514). Thirty days after treatment, 480 patients could be followed and 411 patients (85.6%) were cured. The total effective rate was 96.0%. Mycologic cure rate was 92.3% (443/480). Adverse effect rate was 2.7% (15/563) and they were relieved without any treatment in one or two days. CONCLUSIONS: Miconazole nitrate 1200 mg is effective in the treatment of VVC, with good compliance and few adverse effects. Moreover, it can be accepted easily.

Efficacy of levetiracetam compared with phenytoin in prevention of seizures in brain injured patients: A meta-analysis.

BACKGROUND: Early and/or late onset in patients with brain injury (BI) is associated with a poorer prognosis, and phenytoin (PHT) is standard of care to prevent seizures. Levetiracetam (LEV), an alternative antiepileptic drug, is associated with less cognitive disruption. The purpose of this study was to evaluate the safety and efficacy of LEV in the prevention of brain traumatic seizures with the standard drug PHT. METHODS: Search the publications on comparison the safety and efficacy of LEV against the standard agent PHT in prevention of traumatic seizures in BI to January 2018. After rigorous reviewing on quality, the data were extracted from eligible trials. All trials analyzed the summary hazard ratios of the endpoints of interest. RESULTS: LEV was found not more effective than PHT in terms of overall seizure (odds ratio [OR] = 0.73; 95% confidence interval [CI] = 0.51-1.05; P = .09), and late seizure (OR = 0.64; 95% CI = 0.34-1.19; P = .16) occurrence. However, there is significant difference in terms of early seizure (OR = 0.63; 95% CI = 0.40-0.99; P = .04). Moreover, there were no significant differences in terms of mortality (OR = 0.67; 95% CI = 0.43-1.05; P = .08), or side effects (OR = 1.31; 95% CI = 0.80-2.15; P = .29) between groups. CONCLUSION: The meta-analysis showed that LEV prevention of seizures was associated with early seizure rates that were lower than the PHT-prolonged course of treatment. There is no statistically significant difference in the efficacy and safety profile of PHT and LEV in cases of traumatic BI.

Clinical Value of Machine Learning in the Automated Detection of Focal Cortical Dysplasia Using Quantitative Multimodal Surface-Based Features.

Objective: To automatically detect focal cortical dysplasia (FCD) lesion by combining quantitative multimodal surface-based features with machine learning and to assess its clinical value. Methods: Neuroimaging data and clinical information for 74 participants (40 with histologically proven FCD type II) was retrospectively included. The morphology, intensity and function-based features characterizing FCD lesions were calculated vertex-wise on each cortical surface and fed to an artificial neural network. The classifier performance was quantitatively and qualitatively assessed by performing statistical analysis and conventional visual analysis. Results: The accuracy, sensitivity, specificity of the neural network classifier based on multimodal surface-based features were 70.5%, 70.0%, and 69.9%, respectively, which outperformed the unimodal classifier. There was no significant difference in the detection rate of FCD subtypes (Pearson's Chi-Square = 0.001, p = 0.970). Cohen's kappa score between automated detection outcomes and post-surgical resection region was 0.385 (considered as fair). Conclusion: Automated machine learning with multimodal surface features can provide objective and intelligent detection of FCD lesion in pre-surgical evaluation and can assist the surgical strategy. Furthermore, the optimal parameters, appropriate surface features and efficient algorithm are worth exploring.

Neuropeptide Y suppresses epileptiform discharges by regulating AMPA receptor GluR2 subunit in rat hippocampal neurons.

The present study aimed to investigate the effects of neuropeptide Y (NPY) on the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor glutamate receptor 2 (GluR2) subunit in epileptiform discharge hippocampal neurons. Hippocampal neurons were harvested from neonatal Sprague­Dawley rats aged <24 h and primarily cultured in vitro. At day 12 following culture, hippocampal neurons were divided into the following groups: Control, Mg2+­free, NPY+Mg2+­free and BIBP3226+NPY+Mg2+­free. The action potential of neurons was measured using the whole cell patch clamp technique in the control, Mg2+­free and NPY+Mg2+­free groups. AMPA current (IAMPA) was detected and peak current density was calculated in each group. Alterations in total protein and phosphorylation of the GluR2 subunit were detected by western blot analysis, and GluR2 mRNA expression levels were detected by reverse transcription­quantitative polymerase chain reaction, in each group. The whole cell patch clamp technique demonstrated an abnormal action potential in the Mg2+­free group. The frequency and amplitude of the action potential were significantly greater in the Mg2+­free group compared with the control group, and significantly reduced in the NPY+Mg2+­free group compared with the Mg2+­free group (P<0.05). In the Mg2+­free group, compared with the control group, peak current density was significantly reduced (P<0.05), GluR2 subunit protein content was slightly reduced (P>0.05), phosphorylation levels of GluR2 subunit were significantly greater (P<0.05) and GluR2 mRNA was significantly reduced (P<0.05). In the NPY+Mg2+­free group, compared with the Mg2+­free group, peak current density was significantly greater (P<0.05), phosphorylation levels of GluR2 subunit were significantly reduced (P<0.05) and GluR2 mRNA expression was significantly greater (P<0.05). In the BIBP3226+NPY+Mg2+­free group, compared with the NPY+Mg2+­free group, peak current density was significantly reduced (P<0.05), phosphorylation levels of GluR2 subunit were significantly greater (P<0.05) and GluR2 mRNA expression was significantly reduced (P<0.05). After 3 h of treatment with Mg2+­free extracellular fluid, epileptiform discharge was detected in the cells. NPY inhibited the discharge and its underlying mechanism may be that epileptiform discharge suppressed the function of the AMPA receptor GluR2 subunit. NPY relieved the inhibition of the GluR2 subunit via the Y1 receptor. This may provide a novel direction for future studies on the pathogenesis and treatment of epilepsy.

High lncRNA H19 expression as prognostic indicator: data mining in female cancers and polling analysis in non-female cancers.

Upregulation of lncRNA H19 expression is associated with an unfavorable prognosis in some cancers. However, the prognostic value of H19 in female-specific cancers has remained uncharacterized. In this study, the prognostic power of high H19 expression in female cancer patients from the TCGA datasets was analyzed using Kaplan-Meier survival curves and Cox's proportional hazard modeling. In addition, in a meta-analysis of non-female cancer patients from TCGA datasets and 12 independent studies, hazard ratios (HRs) with 95% confidence interval (CI) for overall survival (OS) and disease-free survival (DFS)/relapse-free survival (RFS)/metastasis-free survival (MFS)/progression-free survival (PFS) were pooled to assess the prognostic value of high H19 expression. Kaplan-Meier analysis revealed that patients with uterine corpus cancer and higher H19 expression had a shorter OS (HR=2.710, p<0.05), while females with cervical cancer and increased H19 expression had a shorter RFS (HR=2.261, p<0.05). Multivariate Cox regression analysis showed that high H19 expression could independently predict a poorer prognosis in cervical cancer patients (HR=4.099, p<0.05). In the meta-analysis, patients with high H19 expression showed a poorer outcome in non-female cancer (p<0.05). These results suggest that high lncRNA H19 expression is predictive of an unfavorable prognosis in two female cancers (uterine corpus endometrioid cancer and cervical cancer) as well as in non-female cancer patients.

High TGF-ß1 expression predicts poor disease prognosis in hepatocellular carcinoma patients.

Transforming growth factor beta (TGF-ß) promotes the pathogenesis of hepatocellular carcinoma (HCC). We evaluated the associations between TGF-ß1 expression and clinicopathological parameters in HCC patients from The Cancer Genome Atlas (TCGA), as well as the prognostic power of TGF-ß1 expression. Eligible studies were retrieved from several databases, and effects (hazard ratios (HRs) with 95% confidence intervals (CIs)) for overall survival (OS), disease-free survival (DFS), recurrence-free survival (RFS), metastasis-free survival (MFS), and progression-free survival (PFS) were pooled to assess the prognostic ability of TGF-ß1 expression in HCC patients. Twelve qualified articles and our TCGA data comprising 2,021 HCC patients were incorporated. In the TCGA analysis, HCC patients with higher TGF-ß1 expression presented a shorter OS than those with lower TGF-ß1 expression (HR = 1.42, p < 0.05). In the meta-analysis, univariate analyses showed that HCC patients with higher TGF-ß1 expression had a shorter OS (pooling HR = 1.71, p < 0.01) and DFS/RFS/MFS/PFS (pooling HR = 1.60, p < 0.01) than those with lower TGF-ß1 expression. In conclusion, our results suggested that high TGF-ß1 expression promotes a poor prognosis in HCC patients.

Platelet derived growth factor receptor alpha is essential for establishing a microenvironment that supports definitive erythropoiesis.

The hematopoietic system undergoes a qualitative change during the embryogenesis of most vertebrates. It is designated as the shift of primitive to definitive hematopoiesis and suitable microenvironment must be established to support this shift. While studying the role of platelet derived growth factor receptor alpha (PDGFR alpha) in embryonic hematopoiesis, we found that it was expressed in a stromal cell component of liver, a major site of this shift, but not in the yolk sac, the site of primitive hematopoiesis. Thus, we considered that development of PDGFRalpha positive stromal cells is an essential requirement for this shift. Without PDFGRalpha positive cell component, erythropoiesis was suppressed in the culture of fetal liver. Moreover, injection of an antagonistic anti-PDGFRalpha monoclonal antibody during embryogenesis suppressed the production of definitive erythrocytes. These indicated that PDGF exerts its effect on a subset of stromal components to prepare a microenvironment that can support the definitive erythropoiesis.

[Effect of IL-24 gene expression on the growth of glioma cells in vitro and in vivo].

OBJECTIVE: To investigate the effect of IL-24 expression on the growth of glioma cells. METHODS: The IL-24 gene was transfected into rat glioma C6 cells with a retroviral vector. The expression of IL-24 in C6/IL-24 glioma cells was confirmed by RT-PCR. MTT assay and flow cytometry were used to study tumor cell proliferation in vitro. Tumorigenicity in vivo was studied in inbred SD male rats by the growth of intracerebrally inoculated tumor. RESULTS: It was confirmed by RT-PCR that the exogenous IL-24 gene expressed in C6/IL-24 cell. The C6/IL-24 cell proliferation in vitro and tumorigenicity in vivo were both inhibited compared with its parental C6 cell. CONCLUSION: IL-24 expression in glioma cells somehow inhibits their growth in vitro and in vivo.

[The analysis of S gene phylogenetic tree of HBV in transmission from father to infant].

OBJECTIVE: To study HBV transmission from father to infants, the study was carried out. METHODS: The study contained 16 pairs of fathers who was HBV carriers, and infants whose mothers wasn't HBV carriers. The infants infected HBV in womb. The homogenous of HBV S gene were compared between fathers and infants, meanwhile HBV gene phylogenetic tree were analyzed. RESULTS: The genotype of 16 pairs fathers and infants were HBV adw. The homogenous of HBV S gene were 98% approximately 100%. The mutation of 488, 491, 494, 530, 531, 546, 581, 621 nucleotide of HBV S gene caused in 112, 113, 114, 126, 131, 143, 156 amino acid substitution. The mutation of 126 amino acid from Threonine to Alanine didn't existed in the gene bank. The sequence was difference from gene classification. CONCLUSION: The homogenous of HBV S gene of fathers and infants was very high. The HBV gene characteristic in China was difference from gene bank.

[Analysis of anti-microbial resistance of Escherichia coli that caused infection in urogenital system].

OBJECTIVE: To study the anti-microbial resistance of Escherichia coli (E.coli) that caused infection in urogenital system. METHOD: Anti-microbial susceptibility tests for 148 strains of E.coli were conducted by disc diffusion technique. RESULTS: In 28 commonly used antibiotics, the resistance rates of E. coli to beta-lactam and quinolones were high (73.6%-86.4%). High resistance rates to the first- and the second-generation cephalosporin (cefradime, cephazolin and cefaclor) were also observed (44%). Resistance rate to ceftazidime is the lowest (10.1%) in the third-generation cephalosporin. The resistance rates of E. coli to piperacillin, pefoperazone and ampicillin were 84.5%, 44.6% and 83.0% respectively. Combined antibiotic and beta-lactam inhibitor gave lower resistance rates than antibiotic alone (piperacillin/tazobactam, cefoporazone/sulbactam and ampicillin/sulbactam were 4.1%, 10.8% and 52.0% respectively, P<0.01). Of 148 E. coli isolates, 38 strains were capable of yielding extended-spectrum beta-lactamases (ESBLs) (25.7%), 110 strains were not able to produce ESBLs (74.3%) and the resistance rates of isolates with ESBLs to 28 antibiotics were significantly lower than those of isolates without ESBLs. CONCLUSION: Antibiotic/beta-lactam inhibitor and nitrofurantoin are effective for urogenital infections caused by E. coli.