Dosimetric Deviations of Bragg-Peak Position Shifts in Uniform Magnetic Fields for Magnetic Resonance Imaging-Guiding Proton Radiotherapy: A Monte Carlo Study

Objective: To investigate dosimetric deviations in scanning protons for Bragg-peak position shifts, which were caused by proton spiral tracks in an ideal uniform field of magnetic resonance (MRI) imaging-guided proton radiotherapy (MRI-IGPRT).

Methods: The FLUKA Monte-Carlo (MC) code was used to simulate the spiral tracks of protons penetrating water with initial energies of 70–270 MeV under the influence of field strength of 0.0–3.0 Tesla in commercial MRI systems. Two indexes, lateral shift (marked as WD) perpendicular to the field and a penetration-depth shift (marked as ΔDD) along the beam path, were employed for the Bragg-peak position of spiral proton track analysis. A comparison was performed between MC and classical analytical model to check the simulation results. The shape of the 2D/3D dose distribution of proton spots at the depth of Bragg-Peak was also investigated. The ratio of Gaussian-fit value between longitudinal and transverse major axes was used to indicate the asymmetric index. The skewness of asymmetry was evaluated at various dose levels by the radius ratio of circumscribed and inscribed circles by fitting a semi-ellipse circle of 2D distribution.

Results: The maximum of WD deflection is 2.82 cm while the maximum of shortening ΔDD is 0.44 cm for proton at 270 MeV/u under a magnetic field of 3.0 Tesla. The trend of WD and ΔDD from MC simulation was consistent with the analytical model, which means the reverse equation of the analytical model can be applied to determine the proper field strength of the magnet and the initial energy of the proton for the planned dose. The asymmetry of 2D/3D dose distribution under the influence of a magnetic field was increased with higher energy, and the skewness of asymmetry for one proton energy at various dose levels was also increased with a larger radius, i.e., a lower dose level.

Conclusions: The trend of the spiral proton track under a uniform magnetic field was obtained in this study using either MC simulation or the analytical model, which can provide an optimized and planned dose of the proton beam in the clinical application of MRI-IGPRT.

COPB2: a transport protein with multifaceted roles in cancer development and progression

The Coatomer protein complex subunit beta 2 (COPB2) is involved in the formation of the COPI coatomer protein complex and is responsible for the transport of vesicles between the Golgi apparatus and the endoplasmic reticulum. It plays an important role in maintaining the integrity of these cellular organelles, as well as in maintaining cell homeostasis. More importantly, COPB2 plays key roles in embryonic development and tumor progression. COPB2 is regarded as a vital oncogene in several cancer types and has been implicated in tumor cell proliferation, survival, invasion, and metastasis. Here, we summarize the current knowledge on the roles of COPB2 in cancer development and progression in the context of the hallmarks of cancer.

Serum glypican4 and glycosylphosphatidylinositol-specific phospholipase D levels are associated with adipose tissue insulin resistance in obese subjects with different glucose metabolism status

OBJECTIVES

Glypican4 (GPC4) is a novel adipokine associated with obesity and insulin resistance. GPC4 was cleaved by the glycosylphosphatidylinositol-specific phospholipase D (GPLD1) in an anchored site of the glycosylphosphatidylinositol, and then was released into the extracellular environment. Herein, we investigated the changes of serum GPC4 and GPLD1 levels in obese subjects with different glucose metabolism status and their relationship with adipose tissue insulin resistance index (Adipo-IR) in Chinese north populations.

METHODS

A total of 221 obese subjects and 37 normal controls (NC) were recruited in this study. Obese subjects were divided into normal insulin (NI) group, hyperinsulinemia (HI) group, impaired glucose tolerance (IGT) group, and type 2 diabetes mellitus (DM) group. Serum GPC4, GPLD1, and adiponectin were determined by commercially available ELISA kits.

RESULTS

Serum GPC4 levels in the HI, IGT, and DM groups were significantly higher than those in the NC and NI groups (2.27 ± 0.58 ng/mL, 2.21 ± 0.60 ng/mL, 2.49 ± 0.67 ng/mL vs. 1.70 ± 0.33 ng/mL, 1.93 ± 0.34 ng/mL, P < 0.05). GPC4 was positively correlated with GPLD1, which was the most important influencing factor of GPC4. Adipo-IR was independently and positively associated with serum GPC4 and GPLD1. For GPC4, after adjustment for confounders, the risk of adipose tissue insulin resistance in subjects with the highest tertile was 2.974-fold that of those with the lowest tertile (OR = 2.974, P = 0.013). For GPLD1, before adjustment for lipids, the increased probability still existed (Model 2, OR = 3.568, P = 0.003).

CONCLUSION

GPC4 is an adipokine associated with adipose tissue insulin resistance, and its activity may be regulated by GPLD1. GPC4 may be a marker for adipose tissue insulin resistance in Chinese north obese populations.

Phylogenetic diversity contributes more to sediment magnetism than abundance during incubation of iron-reducing sediment from a non-active volcanic lake in Northeast China

AIM

This study aimed to analyse bacterial community and biomineralization products from Wudalianchi non-active volcanic field and the relationship between magnetization and bacterial community.

METHODS AND RESULTS

Eighteen sediment samples obtained from Wenbo Lake, high-throughput sequencing and quantitative PCR (qPCR) were separately employed to investigate the bacterial community composition dynamics and abundance variation of the sediment sample with the highest iron-reducing capacity during incubation. The mineralization products were characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction (XRD), Raman spectroscopy, vibrating sample magnetometer (VSM) and variable-temperature magnetism analyses. The results showed that the highest iron reduction rate was 98·06%. Seven phyla were identified as dominant bacterial phyla during the incubation process. Iron-reducing bacteria (FeRB) including Geobacter, Desulfosporosinus and Clostridium were involved in the iron mineralization process. The 16S rDNA copy numbers of sediment decreased quickly and then stayed steady during the incubation. Bacteria with rod-shaped and spheroid species were involved in extracellular iron reduction to produce magnetic particles with massive aggregation and columnar structures on the mineral surface morphologies. The materials produced by the microbial community over the incubation period were sequentially identified as siderite, magnetite and maghemite. The magnetism of the mineral samples gradually increased from 0·31748 to 33·58423 emu g^-1 with increased incubation time. The final products showed relatively stable magnetism under 0-400 K. Meanwhile, the saturation magnetization (M_S ) of the mineralized substance was tightly associated with bacterial diversity (P < 0·05).

CONCLUSIONS

Bacterial community varied during incubation of iron-reducing sediment of volcanic lake. Various iron mineral crystals were in turn formed extracellularly by FeRB. The magnetism of mineralized products was tightly associated with bacterial community.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results not only help us to better understand the iron mineralization of FeRB in the volcanic lake sediments but also provide basic information for the future application of FeRB in environmental bioremediation.

[A real-world study of 176 cases with aplastic anemia treated in outpatient]

目的

探索真实世界门诊治疗再生障碍性贫血（AA）患者的诊断流程、治疗及疗效。

方法

评估2018年1月至2019年12月门诊治疗176例AA患者的诊断流程、治疗方案及疗效。

结果

患者出现症状至首次就诊中位时间7（5～120）个月，就诊原因包括出血（52.3%）、贫血（51.7%）、感染（6.8%）。诊断流程中168例（95.5%）患者完成髂骨骨髓穿刺（骨穿），仅22例（17.1%）完善了多部位骨穿（胸骨分类）；骨髓活检完成率85.1%（143/168）；只有59.5%（100/168）和58.9%（99/168）完成了骨髓流式免疫分型及染色体核型分析；86例（48.5%）完成阵发性睡眠性血红蛋白尿（PNH）克隆筛查；造血祖细胞培养检查完成率最低，仅45例（26.8%）。环孢素A（CsA）联合雄激素及左旋咪唑为最常见治疗方案，总计77例（43.8%），其次为CsA联合雄激素45例（25.6%），单用CsA者24例（13.6%），单用雄激素者16例（9.1%），14例（7.9%）患者确诊后选择中药或未治疗。根据门诊复诊频率将176例患者分为复诊规律组（每年≥4次）130例（73.9%）和复诊欠规律组（每年<4次）46例（26.1%）。复诊规律组6个月有效率较高（52.5%对28.0%，P＝0.005），12个月高质量缓解率更好（40.7%对16.7%，P＝0.027），24个月复发率更低（4.4%对36.4%，P＝0.001）。

结论

真实世界治疗的AA患者诊断流程需重视多部位骨穿检查并完成PNH克隆筛查、流式免疫分型、染色体核型分析及造血祖细胞培养检查；门诊规律复诊患者可获得高质量缓解，复发率低，推荐每年至少复诊4次。

[The diagnostic value of chromosome microarray analysis technique in the genetic causes of children with intellectual disability or global developmental delay]

Objective: To study the value of chromosome microarray analysis (CMA) application in children with developmental delay (DD), intellectual disability (ID), autistic spectrum disorder (ASD) and multiple congenital anomalies (MCA). Methods: Genomic DNA was extracted from peripheral blood samples. Array-based comparative genomic hybridization (array-CGH) analysis and single nucleotide polymorphism array (SNP-array) were performed in 1 320 children with DD/ID, ASD, with or without epilepsy and MCA who were admitted to Peking University First Hospital from 2014 to 2019. The results of genetic etiology test of CMA in children with mental retardation or global DD was summarized. Results: Of 1 320 samples, there were 10 cases of aneuploid abnormality, 6 cases of uniparental disomy and one case of mosaicism, respectively. Pathogenic copy number variations (CNVs) were found in 320 cases and pathogenic CNVs were detected in 23 cases, with a combined detection rate of 26% (343/1 320). CNVs of uncertain clinical significance occurred in 107 cases, accounting for 8.1% (107/1 320). There were 25 cases of possible benign CNVs, accounting for 2% (25/1 320), while benign CNVs were reported in 20 cases, accounting for 1.5% (20/1 320). The detection rate of MCA with DD/ID was 39.8% (130/327). Conclusions: CMA has the advantages of high resolution and covering the whole genome. It can detect the chromosomal abnormalities, microdeletions and duplications seen under the microscope, thus the genetic etiology of children with mental retardation or global DD can be diagnosed.

Efficacy of utidelone plus capecitabine versus capecitabine for heavily pretreated, anthracycline- and taxane-refractory metastatic breast cancer: final analysis of overall survival in a phase III randomised controlled trial

BACKGROUND

Primary analysis of the phase III trial BG01-1323L demonstrated that utidelone plus capecitabine significantly improved progression-free survival (PFS) and overall response rate (ORR) versus capecitabine alone in heavily-pretreated patients with metastatic breast cancer (MBC). Here, we report the final overall survival (OS) analysis and updates of other endpoints.

PATIENTS AND METHODS

In total, 405 patients were randomised 2:1 to receive utidelone (30 mg/m² IV daily, days 1-5, over 90 min) plus capecitabine (1000 mg/m² orally b.i.d., days 1-14) or capecitabine alone (1250 mg/m² orally b.i.d., days 1-14) every 21 days. The secondary endpoint, OS, was estimated using the Kaplan-Meier product-limit approach at a two-sided alpha level of 0.05 after the prespecified 310 death events had been reached. Exploratory analyses of the primary endpoint, PFS, and the secondary endpoint, ORR, were also done. Safety was analysed in patients who had at least one dose of study drug.

RESULTS

At the final OS analysis, the median duration of follow-up was 19.6 months in the utidelone plus capecitabine group and 15.4 months in the capecitabine alone group. In the intention-to-treat population, 313 deaths had occurred at data cut-off, 203 of 270 patients in the combination group and 110 of 135 in the monotherapy group. Median OS in the combination group was 19.8 months compared with 16.0 months in the monotherapy group [hazard ratio (HR) = 0.75, 95% confidence intervals (CI) 0.59-0.94, P = 0.0142]. The updated analysis of PFS and ORR showed that the combination therapy remained superior to monotherapy. Safety results were similar to those previously reported with respect to incidence, severity and specificity. No late-emerging toxicities or new safety concerns occurred.

CONCLUSIONS

For heavily-pretreated, anthracycline- and taxane-resistant MBC patients, utidelone plus capecitabine significantly improved OS versus capecitabine alone. These results support the use of utidelone plus capecitabine as a novel therapeutic regimen for patients with MBC.

Suppression of myocardial HIF-1 by pubertal insulin resistance compromises metabolic adaptation and impairs cardiac function in patients with cyanotic congenital heart disease

Background

Cyanotic congenital heart disease (CCHD) is a complex pathophysiological condition involving systemic chronic hypoxia (CH). A proportion of CCHD patients are unoperated due to various reasons. These patients remain CH all their lives and are at increased risk of heart failure as they age. Hypoxia activates cellular metabolic adaptation to balance energy demands by accumulation of hypoxia-inducible factor 1α (HIF-1α).

Purpose

The aim of this study was to determine the effect of CH on cardiac metabolism and function in CCHD patients and how it relates with age. The mechanistic role of HIF-1α in this process was investigated and potential therapeutic targets were explored.

Methods

CCHD patients (n=20) were evaluated for cardiac metabolism and function by positron-emission tomography/computed tomography and magnetic resonance imaging. Heart tissues collected during surgical intervention were subjected to metabolomic and protein analyses. CH rodent models were generated to enable continuous observation of changes in cardiac metabolism and function. The role of HIF-1α in cardiac metabolic adaptation to CH was investigated using genetically modified animals and isotope-labeled metabolomic-pathway tracing studies.

Results

Prepubertal CCHD patients had glucose-dominant cardiac metabolism and normal cardiac function. By comparison, among patients who had entered puberty, the level of myocardial glucose uptake and glycolytic intermediates were significantly lower, but fatty acids were significantly higher, along with decreased left ventricular ejection fraction. These clinical phenotypes were replicated in CH rodent models. In patients and animals with CH, myocardial HIF-1α was upregulated prior to puberty, but was significantly downregulated during puberty. In cardiomyocyte-specific Hif-1α-knockout mice, CH failed to initiate the switch of myocardial substrates from fatty acids to glucose, leading to inhibition of ATP production and impairment of cardiac function. Increased insulin resistance (IR) suppressed myocardial HIF-1α and was responsible for cardiac metabolic maladaptation under CH during puberty. Pioglitazone significantly reduced myocardial IR, restored glucose metabolism, and improved cardiac function in pubertal animals.

Conclusions

In CCHD patients, maladaptation of cardiac metabolism occurred during puberty, impairing cardiac function. HIF-1α was identified as the key regulator of cardiac metabolic adaptation under CH but its expression was suppressed by pubertal IR. The use of pioglitazone during puberty might help improve cardiac function in these patients.

Metabolic maladaptation in CCHD patients

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): National Natural Science Foundation of China (81525002, 31971048) and Shanghai Outstanding Medical Academic Leader

GW190521: A Binary Black Hole Merger with a Total Mass of 150 M_{⊙}

On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85_{-14}^{+21}  M_{⊙} and 66_{-18}^{+17}  M_{⊙} (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova processes, with only a 0.32% probability of being below 65  M_{⊙}. We calculate the mass of the remnant to be 142_{-16}^{+28}  M_{⊙}, which can be considered an intermediate mass black hole (IMBH). The luminosity distance of the source is 5.3_{-2.6}^{+2.4}  Gpc, corresponding to a redshift of 0.82_{-0.34}^{+0.28}. The inferred rate of mergers similar to GW190521 is 0.13_{-0.11}^{+0.30}  Gpc^{-3} yr^{-1}.

[Ibrutinib treatment for 2 cases of relapsed/refractory autoimmune hemolytic anemia: a pilot study]

目的

探索伊布替尼治疗复发/难治原发性自身免疫性溶血性贫血（AIHA）的疗效及安全性。

方法

2例原发性AIHA患者多次复发，1例有脾切除史，经糖皮质激素、利妥昔单抗及多种免疫抑制药物治疗无效，诊断为复发/难治原发性AIHA。给予伊布替尼起始剂量280 mg/d（例1第3～8周加量到420 mg/d）治疗，观察疗效及安全性。

结果

例1治疗2周后脱离输血，HGB增长>20 g/L，获得部分疗效；10周后HGB 113 g/L伴有代偿性溶血实验室改变，获得完全缓解伴代偿性溶血状态（CRi）。例2治疗2周后脱离输血，HGB增长>20 g/L，获得部分疗效；6周后HGB 118 g/L伴有代偿性溶血实验室改变，获得CRi。2例患者分别随访16周和12周，已维持疗效14周和10周，未复发。伊布替尼治疗期间2例患者血液学不良反应轻，非血液学不良反应轻微。

结论

伊布替尼单药治疗复发/难治原发性AIHA有初步疗效，尚需规范的临床研究试验进一步验证其疗效及安全性。

Overexpression of IGFBP5 Enhances Radiosensitivity Through PI3K-AKT Pathway in Prostate Cancer

Background

Radiotherapy is the main treatment for localized prostate cancer. The therapeutic effects of radiotherapy are highly dependent on radiosensitivity of target tumors. Here, we investigated the impact of insulin-like growth factor-binding protein 5 (IGFBP5) on irradiation therapy in prostate cancer.

Methods

IGFBP5 gene was overexpressed in human prostate cancer cell lines, PC3 and DU145, with transfection of lentivirus expression vector. Radiosensitivity of the cell lines was assessed with colony formation, cell cycle and cell proliferation assays. The expression of proteins associated with the PI3K-AKT pathway was determined by Western blotting. The effect of IGFBP5 knockdown on PI3K-AKT pathway was tested using PI3K inhibitor.

Results

Higher expression of IGFBP5 improved the efficacy of radiotherapy for prostate cancer patients. The effects of IGFBP5 were linked to the PI3K-AKT signaling pathway. Overexpression of IGFBP5 enhanced radiosensitivity and induced G2/M phase arrest in prostate cancer cells. In contrast, it decreased PI3K, p-AKT expression and cell viability. These effects were reversed by IGFBP5 knockdown.

Conclusion

Our results reveal that IGFBP5 regulates radiosensitivity in prostate cancer via the PI3K-AKT pathway. It is, therefore, a potential biomarker of tumors that influences the therapeutic effect of radiotherapy.

Anti-CD19 mAb-conjugated human serum albumin nanoparticles effectively deliver doxorubicin to B-lymphoblastic leukemia cells

B-Lymphoblastic leukemia (B-LL) is the most common childhood hematological malignancy. Although its overall prognosis is good, the outcome after relapse is poor. CD19 is highly expressed on the membrane of most malignant B-cells, and was shown to be a promising therapeutic target of B-LL. In this present work, we designed and synthesized a novel drug carrier, anti-CD19 monoclonal antibody-conjugated human serum albumin nanoparticles (HSA-CD19 NPs). Doxorubicin (DOX) was well encapsulated into the HSA-CD19 NPs to form an anticancer nanodrug DOX/HSA-CD19. DOX/HSA-CD19 was preferentially uptaken by CD19⁺ B-LL cell line KOPN-8. DOX/HSA-CD19 showed strong antiproliferative effect on KOPN-8 cells with an IC₅₀ value of 4.1 μg/mL. Further, proapoptotic Bax and caspase-3 were significantly elevated, but antiapoptotic Bcl2 was reduced in DOX/HSA-CD19 treated KOPN-8 cells, indicating the activation of the apoptosis pathway by the nanodrug. By contrast, DOX/HSA-CD19 did not show affinity to CD19-monocytic cell line, U937, and did not affect its proliferation. Collectively, HSA-CD19 NPs are a kind of effective novel drug carrier, and DOX/HSA-CD19 is a promising antitumor nanodrug for the treatment of B-LL.

[Analysis of adenovirus infection in acute respiratory tract infection cases in Shanghai from 2015 to 2019]

Objective: To study the epidemiological characteristics and mixed infection of adenovirus in acute respiratory tract infections in Shanghai from 2015 to 2019, and to provide scientific basis for the prevention and control of adenovirus. Methods: Acute respiratory tract infections were collected from 3 hospitals in Shanghai from 2015 to 2019. Relevant information was registered and respiratory specimens were sampled for detection of respiratory pathogens by multiplex PCR. Results: A total of 1 543 cases of acute respiratory tract infection were included. The positive rate of adenovirus was 2.92%(45/1 543), the positive rates of influenza like illness (ILI) and severe acute respiratory illness (SARI) were 2.74%(29/1 058) and 3.30%(16/485), respectively. The positive rate of ILI during January-May 2019 was 5.43%(7/129), higher than that in the same period of 2015- 2018 (0.52%-4.48%) (Fisher's exact test value=8.92, P=0.036). The incidence of adenovirus-positive cases was mainly distributed in the first and second quarters, accounting for 62.22% (28/45). The difference of the incidence of adenovirus-positive cases in each quarter was significant (χ(2)= 12.52, P=0.006). The positive rate in the second quarter was highest (6.03%), which was higher than that in other quarters (1.89%-2.93%). There were significant differences among different age groups (χ(2)=16.94, P=0.001), and the positive rate decreased with age (χ(2)=10.16, P=0.001). The positive rate of 13-19 years old group (9.43%) was higher than that of other age groups (1.48%-4.81%). The positive rate of student group (12.07%) was higher than that of other occupations (2.61%). The difference was systematic (χ(2)=11.53, P=0.001). Mixed infection accounted for 31.11% (14/45) of 45 adenovirus positive cases. The mixed infection rates of ILI and SARI were 34.48% (10/29) and 25.00% (4/16), respectively. Among 14 cases of mixed infection, the main mixed infection pathogens of adenovirus were influenza A virus and coronavirus. Conclusion: Adenovirus surveillance should be further strengthened in adolescents with a focus on students and other key groups in the second quarter.

[Analysis on the trend of physical development of children aged 7-17 years old in China from 1982 to 2012]

Data of physical measurement of children aged 7-17 years old in China was from National Nutrition and Health Survey in 1982, 1992, 2002 and 2010-2012. From 1982 to 2012, the height and weight of children aged 7-17 years old continued to increase. The height of urban boys, urban girls, rural boys and rural girls ranged from 118.8 to 171.1, 117.8 to 159.9, 113.3 to 168.2 and 111.7 to 158.1 cm, and weight ranged from 21.3 to 61.4, 20.2 to 53.1, 19.4 to 57.9, and 19.0 to 51.5 kg, respectively. The height and weight of urban children were larger than those of rural children. The height and weight of boys were larger than those of girls, except for adolescents. From 1982 to 2012, the height increment of urban boys, urban girls, rural boys and rural girls was 8.8, 6.2, 12.9 and 10.8 cm, and weight increment was 9.9, 6.2, 9.8 and 7.6 kg, respectively. The increment of urban children was smaller than that of rural children, which implied that the disparity between urban and rural was shrinking. The increment of boys was larger than that of girls, which implied that the gender disparity was increasing.

Total tumor diameter: the neglected value in papillary thyroid microcarcinoma

BACKGROUND

Tumor multifocality is not uncommon in papillary thyroid carcinoma (PTC), especially in micro-PTC. However, assessing the size of the largest tumor may underestimate effect of additional foci. We aimed to investigate the effect of total tumor diameter (TTD) on clinicopathological features of micro-PTC.

METHODS

Data from 442 patients who underwent thyroidectomy with cervical lymph node dissection for PTC were retrospectively analyzed. Patients were classified into subgroups according to multifocality and TTD. The relationships of clinicopathological features among these groups were analyzed.

RESULTS

Multifocality was observed in 119 patients (26.9%). TTD > 1 cm and presence of extrathyroidal extension (ETE) were significantly higher in multifocal tumors compared to unifocal tumor (P < 0.001, P = 0.016, respectively). When comparing multifocal micro-PTC with TTD > 1 cm to those with unifocal micro-PTC or multifocal micro-PTC with TTD ≤ 1 cm, the proportions of cases with ETE, central lymph node metastasis (CLNM), and lateral lymph node metastasis (LLNM) were significantly higher (all P < 0.05). There was no significant difference in terms of these parameters between multifocal micro-PTC with TTD > 1 cm and macro-PTC or multifocal macro-PTC. The risk of CLNM was 2.056 (P = 0.044) times higher in multifocal micro-PTC with TTD > 1 cm than in unifocal micro-PTC.

CONCLUSION

For multifocal micro-PTC, TTD can better assess the aggressiveness of the tumor. Multifocal micro-PTC with TTD > 1 cm was more aggressive than unifocal micro-PTC or multifocal micro-PTC with TTD ≤ 1 cm.

Identification of the CD200R1 promoter and the association of its polymorphisms with the risk of Parkinson's disease

BACKGROUND AND PURPOSE

Neuroinflammation is known to be involved in the pathogenesis of Parkinson's disease (PD). Abnormal activation of microglia plays a key role in this pathological process. CD200R1 is a membrane glycoprotein that is expressed primarily on myeloid cells including microglia and is involved in the maintenance of microglia in a stationary state. Our previous study reported that the regulation of CD200R1 expression is altered in PD patients. Such alteration will lead to neuroinflammation and is related to the pathogenesis of PD. The possible role of promoter polymorphisms for abnormal CD200R1 expression in PD was examined in this study.

METHOD

The UCSC database and dual-luciferase assays were used to confirm the promoter region of CD200R1. The promoter of CD200R1 was sequenced in 457 PD patients and 520 matched healthy controls from the Chinese Han population. Dual-luciferase assays were conducted to examine the promoter activity of CD200R1.

RESULTS

It was confirmed that the promoter of CD200R1 is located in the region 876-146 bp upstream of the coding DNA sequence. The frequencies of rs144721913 (P = 0.001) and rs72952157 (P = 0.022) in the promoter were significantly different between the PD group and control group. rs144721913 increases the risk of PD by approximately 14-fold and rs72952157 by 2.6-fold. The dual-luciferase assay indicated that the rs144721913 T allele and the rs72952157 G allele reduced the transcriptional activity of the CD200R1 promoter.

CONCLUSIONS

For the first time the promoter region of CD200R1 has been defined and two potential risk polymorphisms (rs144721913 and rs72952157) in the region for PD in Chinese Han populations have been reported.

[Investigation of an epidemic cluster caused by COVID⁃19 cases in incubation period in Shanghai]

Objective: To analyze the epidemiological characteristics of a cluster of 5 confirmed COVID⁃19 cases related with the transmission in incubation period of initial case, and find out the infection source and transmission chain.. Methods: According to "The Prevention and Control Protocol for Coronavirus Disease 2019 (Third Edition)" issued by the National Health Commission, a field epidemiological survey was conducted for the 5 cases in January 2020. Nasopharyngeal swabs and sputum samples were collected from them for the detection of 2019-nCoV by real time RT-PCR. Multi prevention and control measures were taken, such as tracking and screening close contacts, medical isolation observation, investigating the epidemiological link, analyzing transmission chain. Results: Case 1, who had common environmental exposure with other COVID⁃19 cases, got sick on 20 January, 2020 and was confirmed on 1 February. Case 2 became symptomatic on 22 January and was confirmed on 27 January. Case 3 got sick on 25 January and was confirmed on 30 January. Case 4 had illness onset on 20 January and was confirmed on 1 February. Case 5 got sick on 23 January and was confirmed on 31 January. Among the 5 cases, case 2 died and the illness of other cases were effectively controlled. After exclusion of other common exposure factors, case 1 had a 6-hour meeting with case 2 and case 3 on 19 January. Case 2 and case 3 might be infected by case 1 during the incubation period. It is the key point for epidemiological investigation. Conclusion: The epidemiological investigation indicates that the transmission might occur in the incubation period of COVID-19 case, close attention should be paid to it in future COVID-19 prevention and control.

[Etiology and clinical features of primary adrenal insufficiency]

Objective: To summarize the etiology of primary adrenal insufficiency (PAI) and analyze its clinical features. Methods: A retrospective analysis was performed in the Department of Endocrinology, Peking Union Medical College Hospital from October 1981 to June 2019. Patients with PAI as the first symptom were enrolled. The etiology of PAI was analyzed and the clinical characteristics was also summarized. Results: A total of 131 patients with PAI were enrolled, including 87 males and 44 females (57 adolescents, and 74 adults). The age ranged from 0 to 73 years. The primary cause of PAI in adolescents was genetic defects (52.6%, 30/57), in which congenital adrenal dysplasia caused by DAX1 gene deficiency accounted for 50.0% (15/30), followed by autoimmunity (22.8%, 13/57). The primary cause of adult PAI was infection (58.1%, 43/74), of which tuberculosis accounted for the majority (93.0%, 40/43), and autoimmune adrenalitis accounted for 19.0% (14/74). Compared with the tuberculosis group, female patients were more common, and the onset age was younger, the plasma cortisol, serum sodium, fasting blood glucose, creatinine and aldosterone were lower (all P<0.05), and serum potassium and renin levels were higher in the autoimmune adrenalitis group (both P<0.05). Conclusions: In the current study, the proportion of PAI caused by infection in the adult group was higher than that in the adolescent group. The most common cause of adult PAI was tuberculosis infection. The most common cause of childhood PAI was genetic defects. Autoimmune damage to the adrenal glands may be more severe than tuberculosis infection.

Direct Detection Constraints on Dark Photons with the CDEX-10 Experiment at the China Jinping Underground Laboratory

We report constraints on the dark photon effective kinetic mixing parameter (κ) with data taken from two p-type point-contact germanium detectors of the CDEX-10 experiment at the China Jinping Underground Laboratory. The 90% confidence level upper limits on κ of solar dark photon from 205.4 kg-day exposure are derived, probing new parameter space with masses (m_{V}) from 10 to 300  eV/c^{2} in direct detection experiments. Considering dark photon as the cosmological dark matter, limits at 90% confidence level with m_{V} from 0.1 to 4.0  keV/c^{2} are set from 449.6 kg-day data, with a minimum of κ=1.3×10^{-15} at m_{V}=200  eV/c^{2}.

Timing of procedural stroke and death in asymptomatic patients undergoing carotid endarterectomy: individual patient analysis from four RCTs

BACKGROUND

The effectiveness of carotid endarterectomy (CEA) for stroke prevention depends on low procedural risks. The aim of this study was to assess the frequency and timing of procedural complications after CEA, which may clarify underlying mechanisms and help inform safe discharge policies.

METHODS

Individual-patient data were obtained from four large carotid intervention trials (VACS, ACAS, ACST-1 and GALA; 1983-2007). Patients undergoing CEA for asymptomatic carotid artery stenosis directly after randomization were used for the present analysis. Timing of procedural death and stroke was divided into intraoperative day 0, postoperative day 0, days 1-3 and days 4-30.

RESULTS

Some 3694 patients were included in the analysis. A total of 103 patients (2·8 per cent) had serious procedural complications (18 fatal strokes, 68 non-fatal strokes, 11 fatal myocardial infarctions and 6 deaths from other causes) [Correction added on 20 April, after first online publication: the percentage value has been corrected to 2·8]. Of the 86 strokes, 67 (78 per cent) were ipsilateral, 17 (20 per cent) were contralateral and two (2 per cent) were vertebrobasilar. Forty-five strokes (52 per cent) were ischaemic, nine (10 per cent) haemorrhagic, and stroke subtype was not determined in 32 patients (37 per cent). Half of the strokes happened on the day of CEA. Of all serious complications recorded, 44 (42·7 per cent) occurred on day 0 (20 intraoperative, 17 postoperative, 7 with unclear timing), 23 (22·3 per cent) on days 1-3 and 36 (35·0 per cent) on days 4-30.

CONCLUSION

At least half of the procedural strokes in this study were ischaemic and ipsilateral to the treated artery. Half of all procedural complications occurred on the day of surgery, but one-third after day 3 when many patients had been discharged.

miR-126 suppresses neuronal apoptosis in rats after cardiopulmonary resuscitation via regulating p38MAPK

In this study, we aimed to evaluate the effect of microRNA-126 (miR-126) on neuronal apoptosis in cardiopulmonary resuscitation rats and to explore the related molecular mechanism. The expression of miR-126 in brain tissues of rats after cardiopulmonary resuscitation was measured by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). The basic parameters of cardiopulmonary resuscitation were recorded by miR-126 mimic injection in rats after cardiopulmonary resuscitation. Hematoxylin-eosin staining was used to observe the pathological changes of hippocampus. Immunohistochemistry was used to observe the expression of p38 and caspase-3 protein. Furthermore, the expression of p38 mitogen-activated protein kinase (p38MAPK), Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase 1/2 (ERK1/2) in rat hippocampus was detected by RT-qPCR and Western blot. In order to confirm whether miR-126 takes part in the p38MAPK pathway in the hippocampus of rats after cardiopulmonary resuscitation, the p38MAPK pathway inhibitor (SB203580) and activator (anisomycin) were added. The results showed overexpression of miR-126 could significantly increase the neurological function score and improve the pathological morphology of hippocampus in rats after cardiopulmonary resuscitation. miR-126 overexpression also could reduce the neuronal apoptosis, p38, and caspase-3 expression in the hippocampus. Moreover, the p38MAPK and JNK expression was downregulated and ERK1/2 expression was upregulated after miR-126 mimic injection (p < 0.05). The results of inhibition of p38MAPK pathway were consistent with those of overexpression of miR-126 (p > 0.05). This study indicated miR-126 could significantly reduce neuronal apoptosis of hippocampus in rats after cardiopulmonary resuscitation, which might be involved in the regulation of p38MAPK pathway.

Search for Light Weakly-Interacting-Massive-Particle Dark Matter by Annual Modulation Analysis with a Point-Contact Germanium Detector at the China Jinping Underground Laboratory

We present results on light weakly interacting massive particle (WIMP) searches with annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B experiment at the China Jinping Underground Laboratory. Datasets with a total live time of 3.2 yr within a 4.2-yr span are analyzed with analysis threshold of 250 eVee. Limits on WIMP-nucleus (χ-N) spin-independent cross sections as function of WIMP mass (m_{χ}) at 90% confidence level (C.L.) are derived using the dark matter halo model. Within the context of the standard halo model, the 90% C.L. allowed regions implied by the DAMA/LIBRA and CoGeNT AM-based analysis are excluded at >99.99% and 98% C.L., respectively. These results correspond to the best sensitivity at m_{χ}<6  GeV/c^{2} among WIMP AM measurements to date.

Effects of milk powder intervention on bone mineral density and indicators related to bone metabolism in Chinese adolescents

The study is to determine the effects of milk powder on bone density and metabolism in healthy adolescents. Vitamin D and calcium supplements increased IGF-1 but did not affect bone mineralization or turnover. Higher vitamin D in combination with sufficient calcium supplementation in such populations requires attention.

INTRODUCTION

Both calcium and vitamin D play an important role in bone mineralization in adolescents.

METHODS

In this one and a half-year randomized controlled trial, 232 participants (aged 12-15 years) were randomly assigned to three intervention groups receiving milk powder fortified with vitamin D 400 IU plus calcium 300, or 600, or 900 mg [Ca3D (n = 54), Ca6D (n = 56), and Ca9D (n = 49)], or one control group maintaining habitual diet [control (n = 73)]. Bone turnover markers, serum intact PTH, 25(OH)D, and IGF-1 levels were measured at baseline and one and a half years, and bone mineral contents and bone areal mineral density were measured by Dual-energy X-ray absorptiometry (DXA) at baseline, one year, and one and a half years.

RESULTS

Baseline average serum 25(OH)D level and calcium intake were 29.4 nmol/L and 363.5 mg/day, respectively. There was a significant increase in bone turnover, total body, hip, lumbar spine bone mineral density (BMD), and total body BMC as well as slight fluctuations in 25(OH)D levels over one and a half years without between-group differences. Significantly decreased serum PTH level was only observed in the Ca6D group (31%, p < 0.0001), in which the intervention effect was also significant (p = 0.0029) compared with the control group. IGF-1 levels increased significantly in all intervention groups (18.5 to 22.8%, p < 0.05) but decreased in the control group (16.5%, p < 0.05), and the group by time interaction was also significant (p = 0.0029).

CONCLUSIONS

Our study showed that in healthy adolescents with low vitamin D status and calcium intake, mild vitamin D and mild to modest calcium supplements increased IGF-1 but did not affect bone mineralization or turnover. Higher vitamin D in combination with sufficient calcium supplementation in such populations requires attention.

P3100Anti-thrombin nanoparticles limit ischemia-reperfusion injury and no-reflow in myocardial infarction

Introduction

Persistent microvascular thrombosis and thrombin signaling in cardiac ischemia reperfusion injury (IRI) combine to promote infarct expansion and heart failure. We have reported previously that treatment of acute ischemic kidney injury (AKI) in rodents with anti-thrombin perfluorocarbon nanoparticles (PFC NP) limits damage to endothelium, reduces “no reflow”, and hastens recovery of kidney function. In cardiac IRI, we hypothesized that thrombin continues to exert deleterious effects well after reperfusion, but whether this strategy is effective in preserving vascular barrier function and preventing no reflow in cardiac IRI is not known. Accordingly, we postulated that sustained local thrombin inhibition with long acting anti-thrombin nanoparticles might limit vascular damage and barrier disruption that otherwise leads to hemorrhage and no reflow.

Methods

14 Sprague Dawley rats undergoing LAD occlusion for 45 min were pretreated with i.v. injection of anti-thrombin PPACK (D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone)-conjugated PFC NP (∼13,000 PPACK per PFC NP), or saline (control) followed by 2 hours of reperfusion. Sham controls (no LAD ligation) were compared. Simultaneous to treatments, a different and unique nontargeted CE PFC NP (CE: Crown Ether core) was injected for subsequent tracking and spectroscopic quantification of the relative distributions and amounts of PFC NP trapped in non-reperfused myocardium. Hearts were perfused with saline in situ, then extracted for ex vivo 19F (fluorine) MRI and spectroscopy at 7T (Bruker). T2* images were acquired for hemorrhage/edema in the area at risk. 19F MRI was acquired for PFC NP trapping (spin echo: TR 2000ms, TE 4.51 ms, FOV 20x20, 64x64 slice 1mm), along with whole heart 19PFC CE spectroscopy.

Results

Fluorine MRI of an intact heart illustrates the trapping of PFC NP in areas of nonreperfusion (Figure) amidst infarct scar region. Quantification of total heart CE PFC NP signal emanating from trapped NP revealed reduced accumulation (−49%) in the hearts of treated rats (0.47±0.09 vs 0.92±0.19, treated vs control; p<0.05). For sham occlusions, minimal deposition of CE PFC NP was observed irrespective of PPACK PFC NP treatment (n=10 per group). Areas of T2* signal indicative of vascular leakage extended beyond that of the 19F signals (Figure T2*), indicating more severe damage and trapping in central infarct zones than in more peripheral border zones after 2 hours.

Discussion

Continued inhibition of thrombin in cardiac IRI with locally-acting PPACK PFC NP preserved vascular integrity, and limited hemorrhage and No Reflow (less trapping). Because these PPACK PFC NP do not prolong bleeding times or coagulation parameters beyond ∼30–60 min after injection, yet maintain prolonged local surveillance against activated thrombin, they represent a potentially useful therapeutic strategy for cardiac IRI.

Search for Subsolar Mass Ultracompact Binaries in Advanced LIGO's Second Observing Run

We present a search for subsolar mass ultracompact objects in data obtained during Advanced LIGO's second observing run. In contrast to a previous search of Advanced LIGO data from the first observing run, this search includes the effects of component spin on the gravitational waveform. We identify no viable gravitational-wave candidates consistent with subsolar mass ultracompact binaries with at least one component between 0.2  M_{⊙}-1.0  M_{⊙}. We use the null result to constrain the binary merger rate of (0.2  M_{⊙}, 0.2  M_{⊙}) binaries to be less than 3.7×10^{5}  Gpc^{-3} yr^{-1} and the binary merger rate of (1.0  M_{⊙}, 1.0  M_{⊙}) binaries to be less than 5.2×10^{3}  Gpc^{-3} yr^{-1}. Subsolar mass ultracompact objects are not expected to form via known stellar evolution channels, though it has been suggested that primordial density fluctuations or particle dark matter with cooling mechanisms and/or nuclear interactions could form black holes with subsolar masses. Assuming a particular primordial black hole (PBH) formation model, we constrain a population of merging 0.2  M_{⊙} black holes to account for less than 16% of the dark matter density and a population of merging 1.0  M_{⊙} black holes to account for less than 2% of the dark matter density. We discuss how constraints on the merger rate and dark matter fraction may be extended to arbitrary black hole population models that predict subsolar mass binaries.

Constraints on Spin-Independent Nucleus Scattering with sub-GeV Weakly Interacting Massive Particle Dark Matter from the CDEX-1B Experiment at the China Jinping Underground Laboratory

We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (m_{χ}) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in m_{χ} are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σ_{χN}^{SI} at 90% confidence level are derived as 2×10^{-32}∼7×10^{-35}  cm^{2} for TI analysis at m_{χ}∼50-180  MeV/c^{2}, and 3×10^{-32}∼9×10^{-38}  cm^{2} for AM analysis at m_{χ}∼75  MeV/c^{2}-3.0  GeV/c^{2}.

P702Anti-thrombin nanoparticles for reduce vascular damage and promote functional recovery in acute ischemic kidney injury well after reperfusion

Introduction

We have shown previously that pretreatment of acute ischemic kidney injury (AKI) in mice prior to reperfusion with anti-thrombin perfluorocarbon nanoparticles (PFC NP) limits damage to endothelium and hastens functional recovery. However, whether such treatments are effective after AKI is established is not known. We hypothesized that thrombin would continue to exert deleterious clotting and molecular signaling effects in AKI well after reperfusion that would respond to sustained local inhibition with long acting anti-thrombin nanoparticles.

Methods

23 C57Bl6 mice underwent bilateral kidney ischemia for 17 min, followed by 2 hours reperfusion and i.v. injection of anti-thrombin PPACK (D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone)-conjugated PFC NP (∼ 13,000 PPACK per PFC NP), or plain PFC NP (control: no drug). At 24 hours BUN was measured, and mice were euthanized for kidney histological assessment (H&E), protein expression (western blot) and eicosanoid mediators of inflammation (LC-MS/MS: AB SCIEX 5500 QTRAP).

Results

BUN at 24 hours after AKI was 63.29±9.09 vs 110.96±6.21 (P<0.002), for treated versus untreated mice, respectively, a 43% improvement. Western blots (Figure) indicated 40% reduction of canonical NF-kB signaling pathway protein p65 (p<0.01) and 2.2 fold increases in Bcl-xL: Bax ratio (P<0.01). Vascular damage, as indicated by glomerular and mesangial hemorrhage (Figure), was reduced, as was tubular cell swelling and edema. Levels of inflammatory procoagulant eicosanoids (e.g., PGE1, TBX2, PGA2, 15-HETE, 5-HETE, etc.) generally were higher in renal medulla than in cortex, and were suppressed by PPACK PFC NP.

Discussion

Continued inhibition of thrombin in AKI with locally-acting PPACK PFC NP preserved vascular integrity, limited renal hemorrhage, mitigated inflammation and tubular cell death, and accelerated functional recovery even when administered 2 hours after reperfusion. Because these PPACK PFC NP do not prolong bleeding times or coagulation parameters beyond ∼30–60 min after injection, yet maintain prolonged local surveillance against activated thrombin, they represent a potentially useful therapeutic strategy for established AKI after an ischemic insult.

Acknowledgement/Funding

DK102691

[Pathogenic characteristics of viral gastroenteritis among pediatric inpatients under five years old during 2014-2017]

Objective: To conduct a viral pathogen surveillance program on pediatric inpatients less than five years old with acute gastroenteritis in Shanghai and to better understand the pathogenic spectrum and molecular features in the target population, for setting up programs on control, prevention, medication and vaccine applications of the diseases. Methods: Fecal samples were collected from inpatients less than 5 years old who were admitted to a pediatric hospital for having acute gastroenteritis. Information related to demographic, clinical and epidemiological features of the patients was also collected. Laboratory assays including ELISA, real-time PCR and nested PCR, were performed to detect the presence of pathogens as rotavirus, calicivirus, astrovirus and adenovirus. Results: A total of 1 018 samples were collected (male 671 and 347 female), with the positive detection rate as 40.57% which peaked from autumn till winter, annually. Calicivirus and rotavirus A presented with the highest detection rates (24.75% and 13.95% respectively). The lowest detection rate was found in the 0-6 month-olds (32.20%). 65% of the patients with positive virus had received antibiotic treatment prior to the hospitalization. However, no statistically significant difference was seen, regarding the rates of antibiotic medication in the virus positive or negative populations (P>0.05). Data from the Rotavirus genotype analysis revealed that G9P[8] genotype was the predominant strain, and causing majority of rotavirus infections in all the age groups. Conclusions: Among the inpatients under 5 years of age in Shanghai, the positive detection rate for Calicivirus was higher than that for rotavirus group A, suggesting the necessity to carefully monitor the changes regarding the pathogenic spectrum and subtypes of the virus. Antibiotics should also be attentively administered, together with the development of suitable vaccine.

[Etiologic and epidemiologic features of acute respiratory infections in adults from Shanghai, during 2015-2017]

Objective: To analyze the etiologic and epidemiological characteristics of adult acute respiratory infections in Shanghai during 2015-2017. Methods: Data was collected from outpatients with acute respiratory infections who visited the Fever Clinics in three hospitals of different levels in three administrative regions of Shanghai, from 2015 to 2017. Basic information and nasopharyngeal swabs were collected from cases in line with the inclusion criteria. Multiplex RT-PCR and bacterial cultures were performed to detect the respiratory pathogens. Results: A total of 806 individuals were enrolled from 2015 to 2017. Respiratory pathogens were identified in 73.45% (592/806) of the cases, with the virus detection rate as 66.75% (538/806). It was found that the major respiratory pathogens for virus detection were influenza A in 326 (40.45%), influenza B in 116 (14.39%), rhinovirus/enterovirus in 39 (4.84%) of the cases. The overall detection rate of bacteria was 16.13% (130/806), including Klebsiella pneumoniae in 90 (11.17%) cases, Staphylococcus Aureus in 46 (5.71%) cases. Other kind of bacteria were not detected in our study. The detection rates on Mycoplasma pneumoniae was 5.33% (43/806) and on Chlamydia pneumonia was 0.37% (3/806). Co-infection with multiple pathogens was detected in 18.61% (150/806) of the cases, including 135 with double infection (accounting for 90.00%), 14 with triple infection and 1 with quadruple infection (accounted for 9.33% and 0.67%, respectively). Among the 150 cases with co-infections, the main identified pathogens were influenza A, Klebsiella pneumoniae, Staphylococcus aureus, and Mycoplasma pneumoniae. Pathogens of acute respiratory infections that identified among the outpatients from the Fever Clinics at different time, region or population, the characteristics were different (P<0.001). Conclusions: In 2015-2017, outpatients with acute respiratory infections in Shanghai were mainly caused by influenza virus or other viruses, however dynamically with its composition, time, region and characteristics of the population. It is necessary to strengthen and combine related medical and preventive services and to develop the appropriate strategies regarding clinical diagnosis and treatment.

[Epidemiological characteristics and antibiotic resistance of Campylobacter spp. among diarrhea outpatients in Shanghai, 2013-2016]

Objective: To understand the epidemiological characteristics and antibiotic resistance profiles of Campylobacter spp. in Shanghai from 2013 to 2016. Methods: Stool samples collected from diarrhea outpatients were cultured for Campylobacter spp., using the membrane filter method in 23 hospitals under the sentinel programs, from 2013 to 2016. All the strains were identified by biochemical tests and PCR. Broth microdilution method was used to investigate the antibiotic resistance of 179 Campylobacter spp. strains that including azithromycin, ciprofloxacin, erythromycin, gentamicin, tetracycline, nalidixic acid, telycin, klinthromycin and flurbenicol. Results: A total of 179 Campylobacter spp. strains were isolated from 10 444 stool samples (1.7%). Campylobacter jejuni and Campylobacter coli appeared as the predominant ones (94.4% and 5.6%). The incidence rate was higher in children than that in adults, with peaks of infections mainly from April to June and October to December. Campylobacter jejuni strains seemed highly resistant to ciprofloxacin (96.4%), tetracycline (83.4%) and nalidixic acid (81.7%). The resistant rates appeared higher on Campylobacter coli strains that isolated from patients. Some strains were resistant to multi-drugs. Conclusions: Campylobacter spp. seemed one of the important pathogens that isolated from outpatients with diarrhea, in Shanghai. Both age and season related characteristics of Campylobacter spp. were seen. Campylobacter spp. isolated from patients was highly resistant to ciprofloxacin, tetracycline and nalidixic acid.

Charged particle radiobiology beamline using tandem accelerator-based MeV protons and carbon ions: a pilot study on the track-end radiation quality, variable biological effectiveness and Bayesian beam dosimetry

For in vitro cell irradiation using tandem accelerator-based MeV protons and carbon ions, by TOPAS simulation, a pilot study of performance evaluation is presented on a collimation beamline for 3 MeV protons and 10 MeV carbon ions from a 2  ×  3 MV tandem accelerator. Based on the elements and source parameters, a collimated beam of 2.8 MeV protons or 2.5 MeV carbon ions, with 5.175 mm or 5.166 mm full width tenth maximum (FWTM), respectively, can be delivered to the target cell dish. TOPAS simulations and/or deterministic algorithms present a Bragg curve of linear energy transfer (LET) (10-70 keV μm^-1) along a 138 μm range of the proton beam, and a declining LET of the carbon beam (900-100 keV μm^-1) within 4 μm range. Based on the biophysical models for relative biological effectiveness (RBE) of protons, TOPAS RBE scorers presents a set of depth-variation curves of the proton RBE (for V79 and DU145 cells), linearly related to the Bragg curve of the proton LET. Based on the microdosimetric-kinetic (MK) theory, in the 4 μm range for a monolayer cell thickness, the mean RBEα (V79 cells) of the carbon ion beam is estimated as 3.612 (late S phase) and 1.737 (G ₁/S phase) for the mean LET of 492 keV μm^-1. For practical irradiations, a tunable proton RBE can be acquired by changing the thickness of the cell dish. For the low-energy high-fluence (rate) beams, indirect beam measurements are proposed to detect the proton-beam induced scattering/recoil protons from a beam-intercepting Mylar film, and the carbon-beam induced backscattered electrons from a gold-deposited Havar-foil beam window. Statistical dosimetry for the indirect measurement is established, using a Bayesian model based on the preset number of detection counts, by which the mean value of the whole-dish dose can be prescribed and the uncertainty introduced in the survival data can be corrected.