[A clinical analysis of 10 cases with cardiac lymphoma]

目的

分析心脏淋巴瘤的发病情况、临床特征、治疗效果及预后。

方法

收集2000年1月至2016年6月期间确诊并有心脏累及的10例淋巴瘤患者的资料，对患者的一般资料、临床表现、病理诊断、实验室检查、心脏累及方式、心脏并发症、治疗方式、疗效及预后进行分析。

结果

3 918例淋巴瘤患者中，心脏累及者10例，其中原发性心脏淋巴瘤（PCL）1例（主要累及左右心房，以心肌内多发结节包块为主），继发性心脏淋巴瘤（SCL）9例（主要为心包包块，其中出现心包积液5例，心肌肿块2例）。男性6例，女性4例，中位年龄55（19~88）岁，主要临床表现为呼吸困难7例，胸痛5例，乏力、水肿各2例。病理类型包括弥漫大B细胞淋巴瘤（DLBCL）7例，T淋巴母细胞淋巴瘤、霍奇金淋巴瘤、Burkitt淋巴瘤各1例。心脏并发症包括充血性心力衰竭7例，心律失常4例（主要为窦性心动过速、心房颤动和房室传导阻滞）。除1例高龄、一般状况差未接受治疗外，其余9例患者均接受治疗（单纯化疗4例，化疗联合放疗5例）。中位随访时间为9（1~28）个月。1例PCL患者化疗后获部分缓解（PR），无进展生存（PFS）期为6个月，总生存（OS）期为21个月。SCL患者中6例起病累及心脏者，治疗后1例获完全缓解，5例获PR，中位PFS期为5个月，中位OS期为19个月；3例病情进展累及心脏者，2例治疗后获PR，1例未治疗者死亡，中位PFS期为4个月，OS因数据截尾，未能获得。

结论

心脏淋巴瘤为少见类型，DLBCL为最常见类型，呼吸困难、胸痛为最常见临床表现，并易出现充血性心力衰竭和心律失常，治疗以系统化疗为主，总体预后差。

Cerebral microbleeds predict infectious intracranial aneurysm in infective endocarditis

BACKGROUND AND PURPOSE

Magnetic resonance imaging (MRI) features such as cerebral microbleeds and sulcal susceptibility-weighted imaging (SWI) or gradient-echo T2* lesions in infective endocarditis (IE) have been associated with the presence of infectious intracranial aneurysm (IIA). Our aim was to validate these MRI predictors for IIA in order to better assist in assessing the appropriate indications for digital subtraction angiography (DSA).

METHODS

The derivation cohort comprised IE patients with neurological evaluation, MRI and DSA at a single tertiary referral center from January 2015 to July 2016. Validation was performed in a cohort of IE patients who underwent MRI and DSA at the same center from 2010 to 2014.

RESULTS

Of 62 patients in the derivation cohort, 10 (16%) had IIAs. Of 129 in the validation cohort, 19 (15%) IIAs were identified. The MRI predictors for IIA consist of (i) contrast enhancement with microbleeds, (ii) cerebral microbleeds >5 mm or sulcal SWI lesions and (iii) any MRI hemorrhages. The sensitivity for the presence of IIA in each group of the derivation cohort was 90%, 80% and 100%, respectively. The sensitivity in the validation cohort was 47%, 68% and 94% respectively. The specificity in the derivation cohort was 87%, 85% and 18%. In the validation cohort, the specificity was similar at 87%, 75% and 27%.

CONCLUSIONS

The absence of MRI hemorrhages may not necessitate the need for DSA.

Charge Transfer Effects in Naturally Occurring van der Waals Heterostructures (PbSe)_{1.16}(TiSe_{2})_{m} (m=1, 2)

van der Waals heterostructures (VDWHs) exhibit rich properties and thus has potential for applications, and charge transfer between different layers in a heterostructure often dominates its properties and device performance. It is thus critical to reveal and understand the charge transfer effects in VDWHs, for which electronic structure measurements have proven to be effective. Using angle-resolved photoemission spectroscopy, we studied the electronic structures of (PbSe)_{1.16}(TiSe_{2})_{m} (m=1, 2), which are naturally occurring VDWHs, and discovered several striking charge transfer effects. When the thickness of the TiSe_{2} layers is halved from m=2 to m=1, the amount of charge transferred increases unexpectedly by more than 250%. This is accompanied by a dramatic drop in the electron-phonon interaction strength far beyond the prediction by first-principles calculations and, consequently, superconductivity only exists in the m=2 compound with strong electron-phonon interaction, albeit with lower carrier density. Furthermore, we found that the amount of charge transferred in both compounds is nearly halved when warmed from below 10 K to room temperature, due to the different thermal expansion coefficients of the constituent layers of these misfit compounds. These unprecedentedly large charge transfer effects might widely exist in VDWHs composed of metal-semiconductor contacts; thus, our results provide important insights for further understanding and applications of VDWHs.

Damage to epitaxial GaN layer on Al2O3 by 290-MeV 238U32+ ions irradiation

Micro-structural characteristics and electrical properties of an n-type GaN epilayer on Al₂O₃ irradiated by 290-MeV ²³⁸U³²⁺ ions to various fluences were investigated using atomic force microscopy (AFM), scanning electron microscopy (SEM), high-resolution X-ray diffraction (HRXRD), and Raman scattering spectroscopy. AFM images show that the nano-hillocks generated, and the diameter and density of the nano-hillocks, increase obviously with increasing ion fluence, accompanied by an increase in surface roughness. SEM images display that the Al, O, and C elements appear on the GaN surface, along with a spiral-like, layered volcanic-cone structure formed at the highest-fluence irradiation. HRXRD reveals that the dislocation density increases, as the lattices gradually expand, and that Ga₂O₃ was produced with increasing ion fluence. Raman scattering spectra show that no N and Ga vacancies were produced, the free-carrier concentration decreases, while its mobility first increases and then exhibits a significant reduction with increasing ion fluence.

Abstract WP325: Peri-operative Neurological Complications of Valve Surgery for Infective Endocarditis Patients With Stroke

Introduction: Surgical valve repair is often delayed for infective endocarditis (IE) patients with stroke. We compared neurological outcome of early and delayed valve surgery and identified pre-surgical imaging characteristics that were associated with perioperative neurological complications.

Methods: We reviewed 228 patients with acute IE diagnosed by modified Duke’s Criteria who underwent cerebral angiogram (CA) between January 2010 - December 2016 at a single center. Patients without pre-surgical CT and MRI were excluded. Date of IE diagnosis was defined as date of antibiotic initiation. Early surgery was defined as valve replacement ≤14 days from date of IE diagnosis, delayed as >14 days. Peri-operative neurological complication is any new clinical or radiologic diagnosis of ischemic or hemorrhagic stroke, and seizure.

Results: 148 of 228 patients underwent valve surgery. 69 patients (46.6%) had early surgery at median 9 days after IE diagnosis, and 79 patients (53.4%) had delayed surgery at median 28 days. On pre-surgical imaging, acute to subacute ischemic stroke was seen in 81% of the early group (n=56) and 78% of the delayed group (n=62, p=0.69). However, 22.8% of patients (n=18) in the delayed group had evidence of subarachnoid hemorrhage (SAH) compared to 10.1 % of patients in the early group (n=7, p=0.04). Despite this finding, delayed group did not have higher rate of perioperative neurological complication than that of the early group (24.1% vs 13%, p=0.95). Overall, 15 surgical patients (10.1%) had perioperative neurological complications: 4 with acute ischemic stroke, 9 with ICH, 1 with both an infarct and ICH, and 3 with seizures. 33.3% of patients who had a perioperative neurological complication had evidence of SAH on pre-surgical imaging (n=6) compared to 14.6% of patients who did not have any neurological complications (n=19, p=0.012). In the group of patients with complications, SAH found prior to surgery were all cortical in the sulci, and 3 cases of SAH were associated with presence of infectious intracranial aneurysm found on pre-surgical CA.

Conclusion: In IE patients with stroke, presence of sulcal SAH on pre-surgical imaging is associated with developing perioperative neurological complications irrespective of surgical timing.

Abstract 162: Microhemorrhages in MRI Predict Infectious Intracranial Aneurysm in Infective Endocarditis

Background: MRI features such as cerebral microbleeds and sulcal susceptibility weighted imaging (SWI) or gradient-echo T2* (GRE-T2*) lesions have been reported to be associated with the presence of infectious intracranial aneurysm (IIA) in infective endocarditis (IE). We aimed to describe the MRI imaging features that predict the presence of IIA.

Methods: The derivation cohort comprised 116 IE patients with neurological evaluation at a single tertiary referral center from January 2015 to July 2016. The MRI predictors associated with IIA was evaluated, and we developed the MRI imaging predictors and assessed sensitivity and specificity. External validation was performed in a cohort of 129 IE patients who underwent digital subtraction angiogram (DSA) at the same center from 2010-2014. We assessed the validity using a receiver operating characteristic curve (ROC).

Results: Of 116 IE patients in the derivation cohort, 10 (9%) had IIAs. Of 129 in the validation cohort, 19 (15%) IIAs were identified. The MRI imaging predictors for IIA consist of 1) contrast enhancement with SWI lesions, 2) cerebral microbleeds > 5mm plus sulcal SWI lesions, and 3) any MRI hemorrhages. The sensitivity for the presence of IIA in each group of the derivation cohort was: 90%, 80%, and 100%, respectively. The sensitivity in the validation cohort was: 47%, 68%, and 94% respectively. The specificity in the derivation cohort was: 87%, 85%, and 18%. In the validation cohort, the specificity was similar (87%, 75%, and 27%).

Conclusions: The suggested MRI imaging predictors can be used as a sensitive and specific tool to support clinical decision-making, especially when invasive DSA is considered for assessment for presence of IIA. The absence of MRI hemorrhages may not necessitate the need for DSA.

Challenging Diagnosis and Inpatient Rehabilitation of Acute Bilateral Neuralgic Amyotrophy Possibly Attributed to Lyme Disease: A Case Report

Neuralgic amyotrophy (NA) is a neurologic syndrome of unknown etiology primarily affecting the brachial plexus. We are reporting an unusual case of acute bilateral NA that was possibly secondary to Lyme disease. The patient demonstrated significant functional gains and was discharged home after 2 weeks of inpatient rehabilitation, supporting the role of inpatient rehabilitation in acute NA. In this report, we discuss the diagnosis, electrodiagnostic progression, pain management, goals for inpatient rehabilitation, and overall prognosis of NA.

LEVEL OF EVIDENCE

V.

[Study of gene mutation in 62 hemophilia A children]

Objective: To analyze the mutation type of FⅧ gene in children with hemophilia A and to explore the relationship among hemophilia gene mutation spectrum, gene mutation and clinical phenotype. Method: Sixty-two children with hemophilia A from Department of Pediatric Hematology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology between January 2015 and March 2017 were enrolled. All patients were male, aged from 4 months to 7 years and F Ⅷ activity ranged 0.2%-11.0%. Fifty cases had severe, 10 cases had moderate and 2 cases had mild hemophilia A. DNA was isolated from peripheral blood in hemophilia A children and the target gene fragment was amplified by PCR, in combination with the second generation sequencing, 22 and 1 introns were detected. Negative cases were detected by the second generation sequencing and results were compared with those of the international FⅧ gene mutation database. Result: There were 20 cases (32%) of intron 22 inversion, 2 cases (3%) of intron 1 inversion, 18 cases (29%) of missense mutation, 5 cases (8%) of nonsense mutation, 7 cases (11%) of deletion mutation, 1 case(2%)of splice site mutation, 2 cases (3%) of large fragment deletion and 1 case of insertion mutation (2%). No mutation was detected in 2 cases (3%), and 4 cases (7%) failed to amplify. The correlation between phenotype and genotype showed that the most common gene mutation in severe hemophilia A was intron 22 inversion (20 cases), accounting for 40% of severe patients, followed by 11 cases of missense mutation (22%). The most common mutation in moderate hemophilia A was missense mutation (6 cases), accounting for 60% of moderate patients. Conclusion: The most frequent mutation type in hemophilia A was intron 22 inversion, followed by missense mutation, again for missing mutation. The relationship between phenotype and genotype: the most frequent gene mutation in severe hemophilia A is intron 22 inversion, followed by missense mutation; the most frequent gene mutation in medium hemophilia A is missense mutation.

Magnetic Resonance Imaging Susceptibility-Weighted Imaging Lesion and Contrast Enhancement May Represent Infectious Intracranial Aneurysm in Infective Endocarditis

Background: Infectious intracranial aneurysm (IIA) can complicate infective endocarditis (IE). We aimed to describe the magnetic resonance imaging (MRI) characteristics of IIA. Methods: We reviewed IIAs among 116 consecutive patients with active IE by conducting a neurological evaluation at a single tertiary referral center from January 2015 to July 2016. MRIs and digital cerebral angiograms (DSA) were reviewed to identify MRI characteristics of IIAs. MRI susceptibility weighted imaging (SWI) was performed to collect data on cerebral microbleeds (CMBs) and sulcal SWI lesions. Results: Out of 116 persons, 74 (63.8%) underwent DSA. IIAs were identified in 13 (17.6% of DSA, 11.2% of entire cohort) and 10 patients with aneurysms underwent MRI with SWI sequence. Nine (90%) out of 10 persons with IIAs had CMB >5 mm or sulcal lesions in SWI (9 in sulci, 6 in parenchyma, and 5 in both). Five out of 8 persons who underwent MRI brain with contrast had enhancement within the SWI lesions. In a multivariate logistic regression analysis, both sulcal SWI lesions (p < 0.001, OR 69, 95% CI 7.8-610) and contrast enhancement (p = 0.007, OR 16.5, 95% CI 2.3-121) were found to be significant predictors of the presence of IIAs. Conclusions: In the individuals with IE who underwent DSA and MRI, we found that neuroimaging characteristics, such as sulcal SWI lesion with or without contrast enhancement, are associated with the presence of IIA

[Distribution and drug resistance of pathogens at hematology department of Jiangsu Province from 2014 to 2015: results from a multicenter, retrospective study]

Objective: To describe the distribution and drug resistance of pathogens at hematology department of Jiangsu Province from 2014 to 2015 to provide reference for empirical anti-infection treatment. Methods: Pathogens were from hematology department of 26 tertiary hospitals in Jiangsu Province from 2014 to 2015. Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or agar dilution method. Collection of drug susceptibility results and corresponding patient data were analyzed. Results: The separated pathogens amounted to 4 306. Gram-negative bacteria accounted for 64.26%, while the proportions of gram-positive bacteria and funguses were 26.99% and 8.75% respectively. Common gram-negative bacteria were Escherichia coli (20.48%) , Klebsiella pneumonia (15.40%) , Pseudomonas aeruginosa (8.50%) , Acinetobacter baumannii (5.04%) and Stenotropho-monas maltophilia (3.41%) respectively. CRE amounted to 123 (6.68%) . Common gram-positive bacteria were Staphylococcus aureus (4.92%) , Staphylococcus hominis (4.88%) and Staphylococcus epidermidis (4.71%) respectively. Candida albicans were the main fungus which accounted for 5.43%. The rates of Escherichia coli and Klebsiella pneumonia resistant to carbapenems were 3.5%-6.1% and 5.0%-6.3% respectively. The rates of Pseudomonas aeruginosa resistant to tobramycin and amikacin were 3.2% and 3.3% respectively. The resistant rates of Acinetobacter baumannii towards tobramycin and cefoperazone/sulbactam were both 19.2%. The rates of Stenotrophomonas maltophilia resistant to minocycline and sulfamethoxazole were 3.5% and 9.3% respectively. The rates of Staphylococcus aureus, Enterococcus faecium and Enterococcus faecalis resistant wards vancomycin were 0, 6.4% and 1.4% respectively; also, the rates of them resistant to linezolid were 1.2%, 0 and 1.6% respectively; in addition, the rates of them resistant to teicoplanin were 2.8%, 14.3% and 8.0% respectively. Furthermore, MRSA accounted for 39.15% (83/212) . Conclusions: Pathogens were mainly gram-negative bacteria. CRE accounted for 6.68%. The rates of Escherichia coli and Klebsiella pneumonia resistant to carbapenems were lower compared with other antibacterial agents. The rates of gram-positive bacteria resistant to vancomycin, linezolid and teicoplanin were still low. MRSA accounted for 39.15%.

[Cerebrospinal fluid adenosine deaminase and its dynamic changes in tuberculous meningitis]

Objective: To explore the diagnostic value of cerebrospinal fluid (CSF) adenosine deaminase (ADA) level in tuberculous meningitis. Methods: We retrospectively analyzed 139 patients (73 males, 66 females) who visited Beijing Chest Hospital for suspected TBM from January 2010 to June 2015. Of them, 99 patients were diagnosed to have TBM, with 45 males and 54 females, and a mean age of (33±15) years. Forty patients were diagnosed as having Non-TBM, with 28 males and 12 females, and a mean age of (35±18) years. All patients underwent lumbar puncture, and CSF ADA, routine, biochemical and bacteriological tests were performed. Thirty-five TBM patients reviewed CSF ADA test after treatment for 4 weeks, 8 weeks and 6 months. Results: The level of CSF ADA in TBM group was higher than that in the non-TBM group, the difference being statistically significant (5.6 U/L vs 2.3 U/L, P=0.000). When the cut-off value of the CSF ADA was 3.8 U/L , the sensitivity and specificity for diagnosis of TBM were 60.6% (95%CI 50.3%-70.1%) and 87.5% (95%CI 72.4%-95.3%), respectively, and the area under the ROC curve was 0.734.The CSF ADA level was (6.7±4.2) U/L in the 35 cases of TBM before treatment. After 4 weeks, 8 weeks and 6 months of anti-tuberculosis treatment, the CSF ADA levels were (4.5±3.3) U/L, (3.7±2.7) U/L and (2.0±1.5) U/L, respectively; all significantly decreased as compared to that before treatment (P<0.001). There was no significant change in the ADA level between 8 weeks and 4 weeks (P=0.128). After 6 months of treatment, the level of CSF ADA was significantly lower than those after 4 and 8 weeks' treatment (P<0.001). Conclusions: CSF ADA in TBM patients was significantly higher than in non-TBM patients. The sensitivity of CSF ADA level in the diagnosis of TBM was poor, but the specificity was better. CSF ADA was significantly reduced and showed dynamic changes with effective anti-tuberculosis treatment and maybe helpful in evaluating the effect of treatment.

Performance of InGaN based green laser diodes improved by using an asymmetric InGaN/InGaN multi-quantum well active region

Series of green laser diodes (LDs) with different (In)GaN barrier layers are investigated. It is found that the optical confinement factor of multi-quantum well (MQW) always increases with increasing indium content of InGaN barrier layer, which results in a decrease of threshold current when indium content of InGaN barrier layer increases from 0 to 5%. However, when a high In content InGaN barrier is used (> 5%), both threshold current and slop efficiency of LDs deteriorate. It may be attributed to the waste of carriers in the potential well at the interface between the last barrier (LB) and the upper waveguide (UWG) layers, which is induced by the piezoelectric polarization effect in high In content InGaN LB layer. Therefore, a new LD structure using a thin thickness of the LB layer to reduce the effect of polarization shows a low threshold current and a high output power even when the In content of barrier layers is as large as 7%.

[The incidence and risk factors of catheter-related-thrombosis during induction chemotherapy in acute lymphocytic leukemia children]

目的

分析初诊急性淋巴细胞白血病（ALL）诱导化疗期外周静脉穿刺中心静脉置管（PICC）患儿导管相关性血栓（CRT）的危险因素。

方法

收集2014年3月1日至2014年12月31日首都医科大学附属北京儿童医院血液肿瘤中心白血病病房行PICC置管的116例初诊ALL患儿临床资料。

结果

①PICC置管后第15天33例（28.4%）患儿发生CRT（CRT组），83例患儿未发生CRT（非CRT组）。②两组在性别、年龄分布、ALL危险度、免疫表型以及置管时两组血常规、凝血功能、是否合并感染、置管静脉方面差异无统计学意义，CRT组右侧置管比例高于非CRT组[75.8%（25/33）对55.4%（46/83），P=0.043]。③CRT组患者均无临床症状，置管第15天D-二聚体高于非CRT组[0.18（0.05~2.45）mg/L对0.11（0.01~5.34）mg/L，P=0.001]。④观察期中出现3例导管相关性并发症，均为导管相关性感染，其中2例并发CRT。⑤置管第33天CRT组26例患者复查B超，19例（73.1%）血栓缩小，6例（23.1%）无明显变化，1例（3.8%）增大。

结论

CRT是初诊ALL患儿诱导化疗期PICC置管的常见导管相关并发症，但症状出现较少，大部分血栓可自行缩小，右侧置管为CRT发生的危险因素；检测D-二聚体水平以及定期进行导管部位B超检查有助于及时发现CRT。

Evolution of differential efficiency in blue InGaN laser diodes before and after a lasing threshold

The optical power emitting from the cavity facet of blue InGaN-based laser diodes (LDs) is measured to investigate the efficiency droop. The efficiency droop behavior of blue InGaN-based LDs near the threshold is confirmed in our experiments. From measurements of optical power at different wavelengths, it is analyzed that the droop behavior of LDs can be ascribed to the efficiency reduction of longer wavelengths. The efficiency of longer wavelengths is subject to the carrier occupation process in quantum levels. In addition, it is found that the droop behavior may be largely affected by the relatively large threshold current of InGaN-based LDs and the screening effect of polarization, and it can be suppressed by stimulated emission.

[Value of (99)Tc(m)-MDP SPECT/CT in clinical decision-making for nasopharyngeal carcinoma and a comparison of the values of different imaging techniques for diagnosing skull-base bone invasion]

Objective: To analyze the clinical value of SPECT/CT in diagnosis of skull base bone invasion and clinical decision-making for nasopharyngeal carcinoma (NPC), and to compare their diagnostic value with SPECT/CT, CT, MRI, and MRI combined with SPECT (MRI-SPECT) for skull base bone invasion. Methods: Before treatment, among 348 newly diagnosed NPC patients, CT scan was performed in 186 patients (group A) and the remaining 162 patients received MRI scan (group B). Clinical doctors then made clinical management decisions according to the CT or MRI results. After that, all patients underwent (99)Tc(m)-MDP SPECT/CT examination for nasopharyngeal local tomography, and the results were provided to the clinical doctors to make clinical management decisions again. The changes between the two clinical management decisions were scored according to diagnosis, range of lesion, staging, treatment regimens, and auxiliary examination. The diagnostic value of CT scan, MRI scan, SPECT/CT and MRI-SPECT for skull base bone invasion was then evaluated and compared. Results: In terms of changes in scores of clinical management decisions, the score of group A was 1.387 and group B was 0.951, showing a significant difference between the two groups by Wilcoxon test (Z=6.570, P<0.001). By χ(2) test, there were correlations between CT and SPECT/CT (χ(2) =98.495, P<0.001), and between MRI and SPECT/CT (χ(2) =32.662, P<0.001). The consistency of CT and SPECT/CT (Kappa=0.713) was greater than MRI and SPECT (Kappa=0.449). The sensitivity of CT, MRI, SPECT/CT and MRI-SPECT was 67.1%, 84.5%, 90.8% and 100%, the specificity was 73.3%, 92.3%, 85.6% and 84.6%, and the area under the ROC curve was 0.702, 0.884, 0.882 and 0.923, respectively. Conclusions: SPECT/CT has important impact on clinical management decision for NPC. In the judgement of skull base invasion, the diagnostic value of SPECT/CT is significantly higher than CT and approximately equal to MRI. SPECT/CT should be one of the routine examination methods of nasopharyngeal carcinoma. In addition, in view of its greater diagnostic value, MRI combined with SPECT should be the focus of future imaging studies.

Emission efficiency enhanced by reducing the concentration of residual carbon impurities in InGaN/GaN multiple quantum well light emitting diodes

A series of samples with varying growth pressure are grown and their optical and structural properties are investigated. It is found that the residual carbon concentration decreases when the reactor pressure increases from 80 to 450 Torr during the InGaN/GaN multiple quantum well growth. It results in an enhanced peak intensity of electroluminescence because carbon impurities can induce deep energy levels and act as non-radiative recombination centers in InGaN layers.

Decreased expression of tumor suppressive miR-874 and its clinical significance in human osteosarcoma

Dysregulation of microRNAs (miRs) is associated with cancer development and progression and aberrant expression of miR-874 have been found in some types of cancer. However, the expression and function of miR-874 in osteosarcoma remain unclear. The aim of this study was to explore the effects of miR-874 in osteosarcoma tumorigenesis and development. The expression level of miR-874 was quantified by real-time reverse transcription-polymerase chain reaction (RT-PCR) in human osteosarcoma cell lines and tissues. Using a miR-874 mimic, cell proliferation and migration assays were performed in an osteosarcoma cell line and tumorigenicity was observed in vivo in order to determine the effects of miR-874 in osteosarcoma cell lines and tissues. MiR-874 was significantly downregulated in osteosarcoma cell lines and clinical specimens. Decreased miR-874 expression was significantly associated with large tumor size, distant metastasis, and advanced clinical stage, and was an independent predictor of poor survival. Overexpression of miR-874 inhibited cell proliferation, invasion and migration in vitro, promoted cell apoptosis in vitro, and suppressed tumorigenicity in vivo. These findings indicate that miR-874 may act as a tumor suppressor in osteosarcoma and could serve as a novel therapeutic agent for miR-based therapy.

Differential resistance of GaN-based laser diodes with and without polarization effect

In this paper, we used numerical calculation and simulation to investigate the differential resistance of GaN-based laser diodes (LDs) with and without polarization effect. We confirmed the existence of a kink at the vicinity of threshold current in the differential resistance curve of GaN-based LDs and found that the kink polarity can be reversed dependent on the polarization effect. The serial parasitic diodes should be included in the theoretical analysis of the equivalent circuit of the LD devices. We determined that the superposition effects of the n-side, active, and p-side regions of the LDs caused the kink and its polarity. We also found that the differential resistance before and after the threshold was dominated by the p-side region and its gradual reduction is related to an electron overflow into p-side. Finally, we studied the effects of cavity facet reflectivity on the kink.

Autoantibody detection to tumor-associated antigens of P53, IMP1, P16, cyclin B1, P62, C-myc, Survivn, and Koc for the screening of high-risk subjects and early detection of esophageal squamous cell carcinoma

The aim of this study was to evaluate the diagnostic values by detecting sera autoantibodies to eight tumor-associated antigens (TAAs) of P53, IMP1, P16, cyclin B1, P62, C-myc, Survivn and Koc full-length recombinant proteins for the screening of high-risk subjects and early detection of esophageal squamous cell carcinoma (ESCC). Enzyme-linked immunosorbent assay was used to detect autoantibodies against the eight selected TAAs in 567 sera samples from four groups, including 200 individuals with normal esophageal epithelia (NOR), 214 patients with esophageal basal cell hyperplasia (BCH), 65 patients with esophageal dysplasia (DYS), and 88 patients with ESCC. In addition, the expression of the eight antigens in esophageal tissues was analyzed by immunohistochemistry. Statistically significant distribution differences were identified among the four groups for each of the individual autoantibodies to six TAAs (P53, IMP1, P16, cyclin B1, P62, and C-myc); the detection rates of antoantibodies were positively correlated with the progression of ESCC. When autoantibody assay successively accumulated to six TAAs (P53, IMP1, P16, cyclin B1, P62, and C-myc), a stepwise increased detection frequency of autoantibodies was found in the four sera groups (6% in NOR, 18% in BCH, 38% in DYS, and 64% in ESCC, respectively), the risks to BHC, DYS, and ESCC steadily increased about 3-, 9-, and 27-folds. The sensitivity and the specificity for autoantibodies against the six TAAs in diagnosing ESCC reached up to 64% and 94%, respectively. The area under the receiver operating characteristic curve for the six anti-TAA autoantibodies was 0.78 (95% confidence interval 0.74-0.83). No more increasing in sensitivity was found with the addition of new anti-TAA autoantibodies. A combination detection of autoantibodies to TAAs might distinguish ESCC patients from normal individuals and the patients with esophageal precancerous lesions.

In situ TEM observation of buffering the anode volume change by using NiTi alloy during electrochemical lithiation/delithiation

A novel Ti3Sn/NiTi shape memory alloy anode with a sandwich structure was fabricated by arc melting. In order to characterize in situ the Ti3Sn/NiTi anode microstructure changes and phase transformations during cycling, a nanoscale lithium battery was set up inside a transmission electron microscope, which consists of Li metal as the cathode, the native Li2O layer on the surface of Li metal as the solid electrolyte, and the Ti3Sn/NiTi as the anode. Only the Ti3Sn intermetallic compound experienced the electrochemical reaction, while the NiTi alloy (inactive with Li(+)) was applied for buffering the Ti3Sn volume change during cycling. An obvious reaction front of Ti3Sn migrated from one end to the other during lithiation, which can also return after delithiation. It provides direct evidence that the NiTi alloy can effectively accommodate the anode volume change during electrochemical lithiation and delithiation.

First Report of Crown Gall, Caused by Agrobacterium tumefaciens on Soapberry (Sapindus delavayi) in China

Soapberry (Sapindus delavayi (Franch.) Radlk.,) plants are widely grown as shade trees in the subtropical to tropical regions of China. In July 2011, large, aerial galls were observed on the above-ground trunks of 5-year-old soapberry plants in two commercial nursery gardens located in Zhejiang Province. Disease incidence was estimated to be 75%. The galls varied in weight from 2 to 24 g and in texture from soft and spongy to hard, and in some cases, the galls completely girdled the trunk. The trees with galls exhibited poor growth compared with healthy trees. Isolations from the grinded and macerated galls yielded nearly pure white, circular, and glistening bacterial colonies on Roy Sauer medium (2). Six random colonies from different galls were selected for bacterial identification, and showed the same morphological, physiological, and biochemical characters and 16S rDNA sequences. All six isolates (isolate SD01 to SD06) were gram negative, rod-shaped bacteria. Carbon source utilization testing with the Biolog GN Bacterial Identification System (version 3.50) confirmed the bacteria as Agrobacterium tumefaciens with a similarity of 0.90. The most-parsimonious tree from the maximum parsimony analysis (PHYLIP package, version 3.68, 500 replicates) of bacterial 16S rDNA gene sequences showed that A. tumefaciens SD01 (GenBank Accession No. JX997939) clustered phylogenetically most closely (99.5% similarity) with A. tumefaciens C58 (AE007870.2). Pathogenicity was confirmed by injecting 3- to 5-week old tomato and sunflower plants and 2-year-old soapberry with approximately 5 μl of the bacterial suspension (10⁸ CFU/ml) in sterile, distilled water. Sterile distilled water was used as a negative control. Ten plants of each treatment were inoculated. Inoculated plants were then transferred to a greenhouse at 25°C. Typical tumors developed at the inoculation sites on tomatoes and sunflower plants 3 weeks after inoculation and on soapberry 6 weeks after inoculation. No symptoms were observed on the control plants. The bacteria that were readily reisolated from the inoculated plants exhibited the same morphological, physiological characters and 16S rDNA sequence as the original culture and were confirmed as A. tumefaciens, fulfilling Koch's postulates. A. tumefaciens is endemic to China and has a very wide host range (1). However, crown gall of soapberry has never been found in China and other countries. To our knowledge, this is the first report of A. tumefaciens on soapberry plants in China. References: (1) M. A. Escobar and A. M. Dandekar. Trends Plant Sci. 8:380, 2003. (2) L. W. Moore et al. Page 17 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria. 3rd ed. N. W. Schaad et al., eds. The American Phytopathological Society, St. Paul, MN, 2001.

Screening of PAX8 mutations in Chinese patients with congenital hypothyroidism

BACKGROUND

Congenital hypothyroidism (CH) is a neonatal endocrine disease with an incidence of 1:2000 to 1:4000 worldwide. In about 85% of patients CH is secondary to thyroid dysgenesis, but its pathogenesis remains unclear. Thyroid transcription factors, such as paired box transcription factor 8 (PAX8), play an important role in thyroid organogenesis and development.

AIM

To screen PAX8 mutations in Chinese CH patients and characterize the features of PAX8 mutations in China.

MATERIALS AND METHODS

Blood samples were collected from 300 CH patients in Shandong Province, China, and genomic DNA was extracted from peripheral blood leukocytes. Using PCR and direct sequencing, exon 3 and exon 4 of PAX8 were analyzed.

RESULTS

Analysis of PAX8 in 300 CH patients revealed heterozygous missense mutations or variations in two unrelated patients; one was a known missense mutation G92A, resulting in an arginine to histidine substitution at codon 31, the other was a missense variation G122T, resulting in the substitution of a glycine at position 41 by a valine residue. The patient with the R31H mutation had CH with thyroid hypoplasia, while the patient with the G41V variation had CH with a eutopic and normal-sized thyroid gland.

CONCLUSION

We report a heterozygous missense mutation and a variation in PAX8 in two out of 300 unrelated Chinese CH patients, showing that the PAX8 mutation rate is very low in CH patients in China.

Changes of Reflex, Non-reflex and Torque Generation Properties of Spastic Ankle Plantar Flexors Induced by Intelligent Stretching

Spasticity, contracture, and muscle weakness are major sources of disability in stroke. Changes of torque-generating capacity as well as reflex and non-reflex properties of ankle plantar flexors induced by strenuous stretching in chronic hemiplegia were investigated. Twelve subjects with a unilateral stroke and 10 healthy controls underwent 30 minutes of strenuous intelligent stretching treatment. Reflex and non-reflex components of spastic hypertonia and force-generating capacity of ankle plantar flexors were investigated. Dorsiflexion (DF) range of motion (ROM) was increased (p=0.002) and passive stiffness and passive resistant torque of the spastic muscles were decreased (p=0.004 and 0.007, respectively), while reflex hyper-excitability diminished slightly but with no statistical significance. The maximal voluntary contraction (MVC) torque of the spastic ankle plantar flexors was increased after the forceful stretching treatment (p=0.041). In contrast, the stretching treatment of the healthy plantar flexors did not change any of the variables measured before and after stretching. The stroke subjects who gained more DF ROM or larger decrement of stiffness achieved greater increment of the peak torque generation after the stretching (r=0.597 with p=0.040 and r=-0.746 with p=0.005, respectively). These results suggest that the strenuous dynamic stretching could improve the force-generating capacity of spastic muscles as well as reduce the passive stiffness and increase ROM.

Type I restriction-modification system and its resistance in electroporation efficiency in Flavobacterium columnare

Flavobacterium columnare, the causative agent of columnaris disease, infects freshwater fish worldwide. However, the pathogenicity of this bacterium is poorly understood due possibly to the lack of an efficient in-frame knockout technique. In order to improve electroporation efficiency, the type I restriction-modification system (R-M system) was cloned and its role in electroporation was examined in F. columnare G(4) strain. The complete sequence of type I R-M system in the bacterium, designated as Fcl, contains all three subunits of type I R-M system, named as fclM, fclS, fclR, respectively, with the identification of a hypothetical gene, fclX. Constitutive transcription of the three genes was observed in F. columnare G(4) by RT-PCR. The ORF of fclM and fclS was cloned into the plasmid pACYC184 and transformed into Escherichia coli TOP10. The resultant E. coli strain, designated as E. coli TOPmt, was transformed with the integrative plasmid pGL006 constructed for F. columnare G(4). The integrative plasmid was re-isolated from TOPmt and incubated with the lysate of F. columnare G(4). The re-isolated integrative plasmid, designated as pGL006', showed higher resistance than pGL006. With pGL006', the electroporation efficiency of the strain G(4) increased 2.6 times, while that of F. columnare G(18) was not obviously improved. Furthermore, a method to improve the electroporation efficiency of F. columnare G(4) was developed using the integrative plasmid methylated by E. coli TOPmt which contains the fclM and fclS gene of F. columnare G(4). Further analyses showed that the fcl gene cluster may be a unique type I R-M system in F. columnare G(4). It will be of significant interest to examine the composition and diversity of R-M systems in strains of F. columnare in order to set up a suitable genetic manipulation system for the bacterium.

Interleukin-10 promoter polymorphisms associated with susceptibility to lumbar disc degeneration in a Chinese cohort

We investigated a possible association between interleukin (IL)-10 single nucleotide polymorphisms (SNPs) and susceptibility to and severity of lumbar disc degeneration (LDD) in a Chinese cohort of 320 patients with LDD and 269 gender- and age-matched controls. The degree of disc degeneration was determined by magnetic resonance imaging using Schneiderman's classification. Genetic analysis of IL-10 promoter polymorphisms (at -1082 A/G, -819 T/C, and -592 A/C) was carried out by PCR-RFLP. A total of 134 herniated lumbar intervertebral discs were collected during surgery for IL-10 mRNA detection. For SNPs at -592, the A allele and AA genotype frequencies were significantly higher in LDD patients than in controls. Similarly, the AA genotype and A allele frequencies at -1082 were significantly higher in cases than in controls. Among the LDD subjects, carriers of AA at -592 and GG at -1082 had significantly lower mean IL-10 mRNA expression than the other two genotypes. The SNPs at each locus were not significantly associated with severity grade in the LDD patients. Logistic regression analyses showed that the AA at -1082, AA at -592, and IL-10 mRNA expression level were independent risk factors for LDD. We conclude that the IL-10 SNPs at -1082 A/G and -592 A/C as well as IL-10 mRNA in the herniated lumbar intervertebral discs are associated with susceptibility to LDD in this Chinese cohort, but not with disease severity.