In-depth analysis reveals complex molecular aetiology in a cohort of idiopathic cerebral palsy

Cerebral palsy is the most prevalent physical disability in children; however, its inherent molecular mechanisms remain unclear. In the present study, we performed in-depth clinical and molecular analysis on 120 idiopathic cerebral palsy families, and identified underlying detrimental genetic variants in 45% of these patients. In addition to germline variants, we found disease-related postzygotic mutations in ∼6.7% of cerebral palsy patients. We found that patients with more severe motor impairments or a comorbidity of intellectual disability had a significantly higher chance of harbouring disease-related variants. By a compilation of 114 known cerebral-palsy-related genes, we identified characteristic features in terms of inheritance and function, from which we proposed a dichotomous classification system according to the expression patterns of these genes and associated cognitive impairments. In two patients with both cerebral palsy and intellectual disability, we revealed that the defective TYW1, a tRNA hypermodification enzyme, caused primary microcephaly and problems in motion and cognition by hindering neuronal proliferation and migration. Furthermore, we developed an algorithm and demonstrated in mouse brains that this malfunctioning hypermodification specifically perturbed the translation of a subset of proteins involved in cell cycling. This finding provided a novel and interesting mechanism for congenital microcephaly. In another cerebral palsy patient with normal intelligence, we identified a mitochondrial enzyme GPAM, the hypomorphic form of which led to hypomyelination of the corticospinal tract in both human and mouse models. In addition, we confirmed that the aberrant Gpam in mice perturbed the lipid metabolism in astrocytes, resulting in suppressed astrocytic proliferation and a shortage of lipid contents supplied for oligodendrocytic myelination. Taken together, our findings elucidate novel aspects of the aetiology of cerebral palsy and provide insights for future therapeutic strategies.

POS0081 CLINICAL FEATURES OF PEDIATRIC BEHÇET’S DISEASE IN CHINA

Background:

Behçet’s disease (BD) is a systemic inflammatory disease involving primarily the oral and genital mucosa, skin and eyes. Some patients exhibit broader involvement with multi-organ system inflammation, causing significant morbidity and mortality. With much of the literature focused on adult-onset BD, the clinical spectrum of BD in children is not well studied. The diagnosis of pediatric BD is difficult to make due to its rarity in childhood, the paucity of experience among pediatricians and the lack of validated diagnostic criteria.

Objectives:

We aim to describe the clinical characteristic of children with Behçet’s disease in China.

Methods:

We performed a cross-sectional cohort analysis of patients with BD recruited between June 2017 and May 2020. We enrolled a total of 848 patients with pediatric BD (onset prior to age 18 years) and 1531 patients with adult-onset BD. Clinical data were collected by retrospective chart review.

Results:

From a cohort of 848 patients with pediatric BD (412 males, 436 females), the average age of disease onset was 11.59 ± 4.11 years and the earliest case was appeared the first symptom at 7 months of age. Clinical manifestations in this group included recurrent oral aphtosis (100%), genital ulcers (77.71%), ocular involvement (30.19%), skin involvement (63.56%), neurological involvement (4.60%), gastrointestinal involvement (20.05%), vascular involvement (9.79%), heart valve involvement (3.66%), arthritis / arthralgia (32.43%), fever (0.35%) and positive pathergy test (21.11%; Table 1). The prevalence of these clinical findings was largely similar to that of adult BD patients with the exception of mild differences in the frequency of gastrointestinal, heart valve, joint involvement and fever. However, the time from symptom onset to diagnosis was significantly longer in children with BD compared to adults (13.34±9.13 years vs. 6.73±33.21 years, P<0.001). The most common initial symptom in pediatric BD was recurrent oral aphtosis (91.57% vs. 86.28% in adults, P<0.001).

In the pediatric group, clinical manifestations also differed between males and females. In addition to oral ulcers, the most common clinical manifestations in male patients were ocular involvement (42.23%), vascular involvement (15.53%), heart valve involvement (5.10%) and epididymitis (9.95%). Among female patients, the frequency of genital ulcers is significantly higher than that of men (86.24% vs. 68.69%, P<0.001).

Conclusion:

We described the clinical characteristics of a large cohort of pediatric BD patients in China. While the clinical manifestations are largely similar to adult BD, the time from symptom onset to diagnosis is significantly delayed in pediatric patients. Our study highlights the need to improve awareness of BD among pediatric providers to facilitate rapid diagnosis and treatment in children.

References:

[1]Yildiz et al. Pediatric Behçet’s disease- clinical aspects and current concepts. Eur J Rheumatol 2020; 7(Suppl 1): S38-S47.

[2]Koné-Paut. Behçet’s disease in children, an overview. Pediatric Rheumatology (2016) 14:10.

Table 1.

Comparison of clinical features of BD in children and adults

Children(n=848)Adult(n=1531)PAge of first symptom (y)11.59±4.1127.08±7.91Sex(M/F)412/436Years of diagnosis (y)13.34±9.136.73±33.21<0.001Recurrent oral aphthosis848 (100%)1518 (99.15%)0.007Genital Ulcers659 (77.71%)1891152 (75.24%)3790.176Ocular signs256 (30.19%)592508 (33.18%)10230.134Cutaneous signs539 (63.56%)3091020 (66.62%)5110.132Neurological signs39 (4.60%)80982 (5.36%)14490.421Gastrointestinal signs170 (20.05%)678244 (15.94%)13870.001Vascular signs83 (9.79%)765162 (10.58%)13690.542Heart valve signs31 (3.66%)817110 (7.18%)1421<0.001Joint signs275 (32.43%)573612 (39.97%)919<0.001Fever3 (0.35%)84522 (1.44%)15090.013Positive pathergy test179 (21.11%)669347 (22.66%)11840.381

Acknowledgements:

China Behcet’ Disease Patients Assossiation.

Disclosure of Interests:

None declared.

POS0833 A RETROSPECTIVE COHORT STUDY IN CHINESE PATIENTS WITH ADULT POLYMYOSITIS AND DERMATOMYOSITIS: RISK OF COMORBIDITIES AND SUBCLASSIFICATION USING MACHINE LEARNING

Background:

Idiopathic inflammatory myopathy (IIM), also known as myositis, refers to a group of heterogeneous disorders including polymyositis (PM), dermatomyositis (DM), inclusion body myositis and immune-mediated necrotising myopathy. Phenotype, pathogenesis, and prognosis vary due to multi-organ involvement and comorbidities. With the clinical application of MSAs, a new classification system for myositis was explored to reduce confusion between subgroups. But it is far from showing the full picture of myositis due to high heterogeneity. Therefore, it is necessary to systematically evaluate the relevant risk factors of myositis for ILD, other rheumatic diseases, and malignancy for better clinical vigilance. And further exploring the subclassification of myositis is critical.

Objectives:

To identify the risk factors in Chinese patients with adult polymyositis and dermatomyositis for their comorbidities and explore a subclassification system.

Methods:

Clinical records of 397 patients with idiopathic inflammatory myopathies were retrospectively reviewed. Logistic regression was used to identify potential risk factors for interstitial lung disease (ILD), other rheumatic diseases, and malignancy after bivariate analysis. Hierarchical clustering and decisional tree were utilized to identify subgroups and explore a subclassification system.

Results:

A total of 119 polymyositis and 191 dermatomyositis patients were included. Anti-PM/Scl, anti-Ro52, anti-aminoacyl-tRNA synthetase and anti-MDA5 (adjusted odds ratios (AOR)=4.779, 1.917, 5.092 and 7.714 respectively) antibodies were risks (p<0.05), whereas overlapping malignancy was protective (AOR=0.107; p=0.002) for ILD across polymyositis, dermatomyositis and the total group. In subgroup models, Raynaud’s phenomenon, arthralgia and semi-quantitative anti-nuclear antibody (AOR=51.233, 4.261, 3.047 respectively) were risks for other overlapping rheumatic diseases (p<0.05). For overlapping malignancy, male and anti-TIF1γ antibodies (AOR=2.533, 16.949) were risks (p<0.05), whereas disease duration and combination of ILD (AOR=0.954, 0.106) were protective in the total group (p<0.05); while anti-NXP2 antibodies were identified as risk factors (AOR=73.152; p=0.038) in polymyositis. Hierarchical clustering suggested a subclassification with 6 subgroups: malignancy overlapping dermatomyositis, classical dermatomyositis, polymyositis with severe muscle involvement, dermatomyositis with ILD, polymyositis with ILD, and overlapping of myositis with other rheumatic diseases according to the characteristics of grouped patients. Accuracy of the classification and regression trees model was 0.768 (95% CI 0.711 to 0.819) on training set and 0.633 (95%CI 0.499 to 0.754) on test set.

Conclusion:

Accompanying ILD, other rheumatic diseases and malignancy are strongly associated with clinical manifestation and myositis-specific or myositis-associated autoantibodies among Chinese polymyositis and dermatomyositis patients. The subclassification system proposed a more precise phenotype defining toward stratified treatments.

Acknowledgements:

The study was supported by the Natural Science Foundation of China [No. 81803932] and the Natural Science Foundation of Guangdong Province [No. 2018030310025 and 2017A030313868]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Disclosure of Interests:

None declared

Arhgef2 regulates neural differentiation in the cerebral cortex through mRNA m6A-methylation of Npdc1 and Cend1

N⁶-methyladenosine (m⁶A) is emerging as a vital factor regulating neural differentiation. Here, we report that deficiency of Arhgef2, a novel cause of a neurodevelopmental disorder we identified recently, impairs neurogenesis, neurite outgrowth, and synaptic formation by regulating m⁶A methylation. Arhgef2 knockout decreases expression of Mettl14 and total m⁶A level significantly in the cerebral cortex. m⁶A sequencing reveals that loss of Arhgef2 reduces m⁶A methylation of 1,622 mRNAs, including Npdc1 and Cend1, which are both strongly associated with cell cycle exit and terminal neural differentiation. Arhgef2 deficiency decreases m⁶A methylations of the Npdc1 and Cend1 mRNAs via down-regulation of Mettl14, and thereby inhibits the translation of Npdc1 and nuclear export of Cend1 mRNAs. Overexpression of Mettl14, Npdc1, and Cend1 rescue the abnormal phenotypes in Arhgef2 knockout mice, respectively. Our study provides a critical insight into a mechanism by which defective Arhgef2 mediates m⁶A-tagged target mRNAs to impair neural differentiation.

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Arhgef2 mediates total m⁶A level via Mettl14

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Arhgef2 affects m⁶A methylations of the Npdc1 and Cend1 mRNAs

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Decreased m⁶A methylations inhibits translation of Npdc1 and nuclear export of Cend1

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Reduced protein expression of Npdc1 and Cend1 hinders neural differentiation

Bi-allelic mutation in Fsip1 impairs acrosome vesicle formation and attenuates flagellogenesis in mice

Fibrous sheath interacting protein 1 (Fsip1) is a cytoskeletal structural protein of the sperm flagellar proteome. A few studies have reported that it plays a vital role in the tumorigenesis and cancer progression. However, little is known about the role of Fsip1 in spermatogenesis and mammalian sperm flagellogenesis. Fsip1 protein showed the highest expression in round spermatids, and was translocated from nucleus to the anterior region of the elongating spermatid head. To investigate its role we constructed homozygous Fsip1 null (Fsip1^−/−) mice. We found that the homozygous Fsip1^−/− mutant mice were infertile, with a low sperm count and impaired motility. Interestingly, a subtle phenotype characterized by abnormal head shape, and flagella deformities was observed in the sperm of Fsip1^−/− mutant mice similar to the partial globozoospermia phenotype. Electron microscopy analysis of Fsip1^−/− sperm revealed abnormal accumulation of mitochondria, disrupted axoneme and retained cytoplasm. Testicular sections showed increased cytoplasmic vacuoles in the elongated spermatid of Fsip1^–/–mice, which indicated an intraflagellar transport (IFT) defect. Using proteomic approaches, we characterized the cellular components and the mechanism underlying this subtle phenotype. Our result indicated that Fsip1^–/–downregulates the formation of acrosomal membrane and vesicles proteins, intraflagellar transport particles B, and sperm flagellum components. Our results suggest that Fsip1 is essential for normal spermiogenesis, and plays an essential role in the acrosome biogenesis and flagellogenesis by attenuating intraflagellar transport proteins.

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Disruption of Fsip1 leads to infertility with partial globozoospermia phenotype.

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Homozygous deletion of Fsip1 alters spermiogenesis.

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Fsip1 Knockout disrupts acrosome vesicle formation.

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Fsip1 motif analysis involves in internal fertilization.

The cross-sectional and longitudinal associations of dietary patterns with knee symptoms and MRI detected structure in patients with knee osteoarthritis

OBJECTIVES

To examine the cross-sectional and longitudinal associations of dietary patterns with knee symptoms and structures in patients with knee osteoarthritis (OA).

METHODS

Participants with symptomatic knee OA were recruited from a randomised, placebo-controlled trial conducted in Tasmania (N = 259) and Victoria (N = 133). Diet was assessed by the Anti-Cancer Council of Victoria food frequency questionnaire. Factor analysis was used to identify dietary patterns. Knee symptoms were assessed using Western Ontario and McMaster Universities Arthritis Index (WOMAC) and structures using MRI. Multivariable linear regressions were used to examine associations.

RESULTS

Three dietary patterns ("high-fat", "healthy" and "mixed") were identified in whole sample. Participants with higher "healthy pattern" score had lower total WOMAC, pain, function and stiffness scores at baseline but the associations were not significant over 24 months. Three ("western", "vegetable and meat" and "mediterranean") and two ("processed" and "vegetable") patterns were identified in Tasmania and Victoria, respectively. Cross-sectionally, only "mediterranean pattern" and "vegetable pattern" scores were significantly and negatively associated with total WOMAC or function scores. Longitudinally, participants with higher "western pattern" had worsening function (β: 0.35, 95%CI: 0.03, 0.67) and total WOMAC (β: 0.40, 95%CI: 0.07, 0.72) scores; furthermore, "vegetable pattern" was associated with decreased WOMAC stiffness score (β: -0.47, 95%CI: -0.93, -0.02). In contrast, dietary patterns were largely not associated with structural changes.

CONCLUSION

Some healthy dietary patterns were associated with reduced joint symptoms but dietary patterns were not associated with joint structure in this sample with knee OA. Further studies are required to confirm these findings.

Olfactory impairment as an early marker of Parkinson's disease in REM sleep behaviour disorder: a systematic review and meta-analysis

Olfactory impairment and rapid eye movement sleep behaviour disorder (RBD) are prodromal symptoms of Parkinson's disease (PD) that may be associated with each other. This review aims to investigate the significance of olfaction in the diagnosis and prognosis of patients with RBD and to assess moderating factors affecting olfactory performance. We searched articles on olfaction in RBD and PD in five electronic databases. We identified 32 studies for the systematic review and used 28 of those, including 2858 participants for meta-analysis. Results revealed significant deficits in odour identification (g=-1.80; 95% CI: -2.17 to -1.43), threshold (g=-1.29; 95% CI: -1.67 to -0.91), discrimination (g=-1.08; 95% CI: -1.28 to -0.87) and overall olfactory function (g=-1.64; 95% CI: -1.94 to -1.35) in patients with RBD. Except for the Unified Parkinson's Disease Rating Scale Part III scores, none of the known moderating variables (including age, sex, disease duration and years of education) accounted for the olfactory function heterogeneity in patients with RBD. We identified similar olfactory impairments in patients with RBD and patients with PD (either with or without underlying RBD). These findings suggest that olfactory impairment may be a sensitive and stable diagnostic biomarker of RBD and appears to be useful for identifying patients with idiopathic RBD at high risk for early conversion to PD.

MicroRNA-26b-5p alleviates cerebral ischemia-reperfusion injury in rats via inhibiting the N-myc/PTEN axis by downregulating KLF10 expression

MicroRNAs plays important role in cerebral ischemia-reperfusion (CIR). However, the role of miR-26b-5p in CIR injury remains unclear. PC12 cells were treated with oxygen-glucose deprivation (OGD) for 0 h, 2 h, 4 h, 6 h, and then reoxygenated for 24 h to construct an in vitro I/R model. Then, miR-26b-5p mimic, small interfering RNA of KLF10 and KLF10 overexpression plasmid were transfected into cells respectively for mechanism study. Our results showed that miR-26b-5p was downregulated in OGD/R-induced PC12 cells. After overexpression of miR-26b-5p, cell proliferation ability was enhanced, apoptosis, ROS and inflammatory mediators were inhibited. Bioinformatics analysis indicated that miR-26b-5p was directly bound to the 3' UTR of KLF10, and downregulated the expression of KLF10. KLF10 was upregulated in OGD/R cells, and transfection with si-KLF10 promoted cell proliferation and reduced apoptosis, NO concentration and inflammatory factor secretion. Moreover, pcDNA-KLF10 reversed the inhibitory effects of miR-26b-5p mimic on apoptosis, NO content and inflammatory factor secretion, as well as the downregulation of N-myc and PTEN expression. Meanwhile, I/R rat models were constructed and divided into sham operation group (femoral artery isolation only), model group (middle cerebral artery occlusion model of rats was prepared by thread embolization), treatment group (200 µL of miR-26b-5p mimic was injected into the brain of model rats). We observed that the infarct size of brain tissue was reduced, KLF10 expression was downregulated, and apoptosis and inflammatory response were reduced. These results suggest that miR-26b-5p had protective effects on CIRI and it may be a potential treatment target.

Tafolecimab, a novel potential long-acting PCSK9 monoclonal antibody: efficacy and safety in healthy and hypercholesterolemia subjects

Background

LDL cholesterol (LDL-C) is a well-established risk factor for cardiovascular disease. PCSK9 binds LDL receptors, targeting them for degradation. The dosing intervals for currently available PCSK9 monoclonal antibodies are once every 2 or 4 weeks. Tafolecimab, a novel recombinant human PCSK9 monoclonal antibody, was found to have higher affinity with PCSK9 and show longer LDL-C reduction compared to evolocumab in preclinical studies.

Purposes

The objectives for the SAD and MAD studies were to investigate the safety and efficacy of tafolecimab and explore the optimal dosing schedule.

Methods

The phase 1 study was a randomized, placebo-controlled, double-blind, single-ascending dose study (SAD) in Chinese healthy subjects, who were randomized 3:1 to tafolecimab and placebo (n=58). SAD subjects received tafolecimab subcutaneously at 25/75/150/300/450/600mg, or intravenously at 75/450mg, monitored up to day 84. The phase 2 study was a randomized, double-blind, placebo-controlled, repeated-dosing, multiple ascending dose (MAD) study in patients with hypercholesterolemia, who were randomized 4:1 to tafolecimab and placebo (n=60). MAD subjects received tafolecimab subcutaneously at 75/140mg every 2 weeks, 300/420mg every 4weeks, 450/600mg every 6 weeks up to day 84 or 98 with 3 months follow-up.

Results

In the SAD, the maximum mean reduction in LDL-C ranged from 52.2% to 72.1% and was achieved as early as 5 days (figure 1a). The duration of LDL-C reduction was tafolecimab dose dependent. In the MAD, the mean LDL-C concentrations were reduced by tafolecimab for each dose at 12 weeks relative to baseline (ranging from 54.30% to 72.26%; p&lt;0.001). Particularly, a 56.52% (−72.50%, −40.54%) reduction of LDL-C was observed in the cohort of 600mg Q6W. The effect sustained till week 14 (8 weeks after the last dose) where there was still a 43.46% (−60.96%, −25.96%) reduction from baseline (figure 1b). The mean reduction of Lp(a) at week 12 ranged from 24.04% to 50.59% relative to baseline. Tafolecimab reduced the other lipids when comparing with placebo. The pharmacokinetics/pharmadynamics (LDL-C) profiles of tafolecimab were well characterised and support the potential dosing interval of 6–8 weeks subcutaneously.

Both healthy and hypercholesterolemia subjects are generally tolerable to tafolecimab. Reported treatment-emergent adverse events (TEAEs) were: tafolecimab 23 (52.3%) vs. placebo 8 (57.1%); tafolecimab 34 (70.8%) vs. placebo 9 (75.0%) in the SAD and MAD respectively. There were no serious TEAEs or events leading to death or treatment discontinuation in both SAD and MAD.

Conclusions

Tafolecimab was well tolerated in both healthy and hypercholesterolemia in Chinese subjects, and improved lipid profile including LDL-C, Lp(a) and other lipids. The sustained effects on LDL-C suggests the potential of tafolecimab as a long-lasting PCSK9 inhibitor with dosing interval of 6–8 weeks or beyond.

Figure 1. LDL-C: Percent change from baseline

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Innovent Biologics (Suzhou), China

LncRNA MALAT1 inhibits osteogenic differentiation of mesenchymal stem cells in osteoporosis rats through MAPK signaling pathway

OBJECTIVE

The aim of this study was to explore whether long non-coding ribonucleic acid metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1) could lead to osteoporosis (OP) by stimulating the activation of the mitogen-activated protein kinase (MAPK) signaling pathway.

MATERIALS AND METHODS

The OP model was first successfully established in rats. The expression of lncRNA MALAT1 in OP rats and normal rats was detected via quantitative Polymerase Chain Reaction (qPCR). Bone marrow mesenchymal stem cells (BMSCs) were cultured and transfected to establish the MALAT1 knockdown model. Subsequently, the apoptosis of mesenchymal stem cells in MALAT1 siRNA group and NC siRNA group was detected via flow cytometry. Meanwhile, the expressions of the MAPK signaling pathway proteins related to OP were detected via Western blotting. After alkaline phosphatase (ALP) staining in cells of both groups, early osteogenic differentiation of BMSCs was observed.

RESULTS

The results of qPCR showed that the expression of lncRNA MALAT1 in OP rats was significantly lower than that of normal rats. It was observed under a fluorescence microscope that there were a large number of siRNA particles in BMSCs. The expression of lncRNA MALAT1 in cells was detected via Real Time-fluorescence qPCR as well. The results indicated that siRNA transfection could effectively inhibit the expression of lncRNA MALAT1, indicating successful transfection. Flow cytometry revealed that no significant difference was observed in the apoptosis of BMSCs between the MALAT1 siRNA group and NC siRNA group. Besides, the results of Western blotting showed that the expression levels of the MAPK signaling pathway-related proteins extracellular signal-regulated kinase 1/2 (ERK1/2) and P38 in MALAT1 siRNA group were significantly higher than those of the NC siRNA group. This indicated that inhibiting the expression of lncRNA MALAT1 might promote the activation of the OP-related MAPK pathway. According to the results of ALP staining, the depth of staining in MALAT1 siRNA group was markedly declined when compared with the NC siRNA group. Quantification of ALP activity demonstrated that ALP activity in the MALAT1 siRNA group was markedly declined compared with the NC siRNA group. The above results suggested that suppressing the expression of lncRNA MALAT1 could reduce the ALP activity of BMSCs. Furthermore, lncRNA MALAT1 inhibited osteogenic differentiation of BMSCs.

CONCLUSIONS

LncRNA MALAT1 was lowly expressed in OP rats. Moreover, it inhibited osteogenic differentiation of BMSCs by enhancing the activation of the MAPK signaling pathway, thereby promoting OP progression.

Second harmonic generation microscopy using pixel reassignment

Second harmonic generation (SHG) microscopy is expected to be a powerful tool for observing the cellular-level functionality and morphology information of thick tissue owe to its unique imaging properties. However, the maximum attainable resolution obtainable by SHG microscopy is limited by the use of long-wavelength, near-infrared excitation. In this paper, we report the use of pixel reassignment to improve the spatial resolution of SHG microscopy. The SHG signal is imaged onto a position-sensitive camera, instead of a point detector typically used in conventional SHG microscope. The data processing is performed through pixel reassignment and subsequent deblurring operation. We present the basic principle and a rigorous theoretical model for SHG microscopy using pixel reassignment (SHG-PR). And for the first time, the optimal reassignment factor for SHG-PR is derived based on the coherent characteristics and the dependence of wavelength in SHG microscopy. To evaluate the spatial resolution improvement, images of nano-beads separated by different distances and of a microtubule array have been simulated. We gain about a 1.5-fold spatial resolution enhancement compared to conventional SHG microscopy. When a further deblurring operation is implemented, this method allows for a total spatial resolution enhancement of about 1.87. Additionally, we demonstrate the validity of SHG-PR for raw data with noise. LAY DESCRIPTION: Second harmonic generation (SHG) microscopy has emerged as a powerful imaging technique in clinical diagnostics and biological research. SHG microscopy is label-free and provides intrinsic optical sectioning for three-dimensional (3D) imaging. However, a near-infrared excitation wavelength results a restriction in the maximum attainable spatial resolution of SHG microscopy. In this paper, we present a simple resolution-enhanced SHG imaging method, SHG microscopy using pixel reassignment (SHG-PR). We demonstrate a rigorous theoretical model for SHG-PR and derive the optimal reassignment factor. The simulation result shows the clear improvement of the image resolution and contrast in the SHG-PR after deblurring operation. The FWHM value of single microtubule shows that SHG-PR enables a spatial resolution enhancement by a factor of 1.5, compared to conventional SHG microscopy. After a proper deblurring operation, this method allows for a total spatial resolution enhancement of about 1.87. The improvements of spatial resolution and contrast are still valid for raw data with noise. It is expected that this method can contribute towards new insights in unstained tissue morphology, interaction of cells, and diseases diagnosis.

[Progress of cohort studies in countries from Asia and Europe]

Objective: To share related knowledge and experiences with countries along the line, literature regarding current cohort studies was summarized. Distribution, establishment and development of cohort studies among large prospective general population were analyzed in 17 countries of Western Asia and the 16 countries of Central and Eastern Europe. Methods: Literature review was conducted to collect basic information on cohort studies, with descriptive study used to analyze the characteristics of these cohort studies. Results: There were 562 cohort studies with sample size as more than 1 000 stated in Western Asia and Central and Eastern Europe, including 468 (83.27%) carried out in the nation itself and 94 (16.73%) with international multicentered collaboration. According to the nature of cohort studies, 347 (61.74%) were etiologically based. As for the contents involved, 310 (55.16%) of them targeted on chronic/non-communicable diseases, 125 (22.24%) concentrated on maternal and child health. Among those on chronic/non-communicable diseases, 51 (16.45%) were on cancers and 83 (26.77%) on cardiovascular disease studies. There appeared 10 large prospective cohort studies targeting on general population, mainly ongoing in Iran and European countries, with a duration of 8-29 years, including 4 of them with sample size as more than 50 000. In terms of the contents, epidemiological investigation, physical examination and biological samples collection took the major parts. Few papers were published in 9 out of the 10 cohort studies at the early stage of those projects but the number of papers increased annually and stabilized to certain extent. Conclusions: The regional distribution of cohort studies carried out in countries from the Western Asia and Central and Eastern European areas appeared unbalanced. Contents of these designs would mainly involve etiological studies, with focus on non-communicable diseases as cancer, cardiovascular disease, diabetes, respiratory diseases, mental and psychological diseases, and maternal and infant health etc.. However, only few large prospective cohort studies would base on general population.

Deep Learning for Prediction of the Air Quality Response to Emission Changes

Efficient prediction of the air quality response to emission changes is a prerequisite for an integrated assessment system in developing effective control policies. Yet, representing the nonlinear response of air quality to emission controls with accuracy remains a major barrier in air quality-related decision making. Here, we demonstrate a novel method that combines deep learning approaches with chemical indicators of pollutant formation to quickly estimate the coefficients of air quality response functions using ambient concentrations of 18 chemical indicators simulated with a comprehensive atmospheric chemical transport model (CTM). By requiring only two CTM simulations for model application, the new method significantly enhances the computational efficiency compared to existing methods that achieve lower accuracy despite requiring 20+ CTM simulations (the benchmark statistical model). Our results demonstrate the utility of deep learning approaches for capturing the nonlinearity of atmospheric chemistry and physics and the prospects of the new method to support effective policymaking in other environment systems.

Isolation and characterization of endothelial progenitor cells from canine bone marrow

Endothelial progenitor cells (EPC) are located predominantly in the bone marrow. These cells are useful for treating human vascular diseases; they also are a possible target for restricting blood vessel growth for tumors. Little is known about canine EPC. We investigated a bone marrow EPC isolation method that combines the whole bone marrow culture method and the differential adherent speed method using stillborn canines. MTT proliferation, flow cytometry detection, Dil-ac-LDL uptake, FITC-UEA-1 binding and matrigel assays were used to identify and characterize EPC. We isolated two types of EPC: early EPC and late EPC. We found that isolated cells produced typical colony and cobblestone morphology, and were positive for CD31, CD34, CD133 and VEGFR-2. Significant differences were observed in the intensity of expression between early and late EPC, which suggests their different roles during angiogenesis and vasculogenesis. Both early and late EPC were positive for Dil-ac-LDL and FITC-UEA-1, and displayed tube formation when re-suspended in matrigel, both of which are important functional criteria for identifying EPC. Our method is a novel, effective and efficient way to produce enriched EPC.

[Changes of urinary monocyte chemotactic protein 1 and epidermal growth factor and their correlations with clinicopathology in idiopathic membranous nephropathy patients]

Objective: To explore the changes and clinical value of urinary monocyte chemotactic protein 1 (MCP-1), epidermal growth factor (EGF) and their ratio in patients with idiopathic membranous nephropathy (IMN). Methods: A total of 67 IMN patients were enrolled according to kidney biopsy in the Department of Nephrology of the First Affiliated Hospital of Zhengzhou University from January 2017 to December 2018. The patients included 28 males and 39 females, with an average age of (47.6±14.2) years. Eighteen age-and sex-matched healthy controls were also enrolled. Clinical and pathological data, blood and urine samples of all subjects were collected. Urinary MCP-1 and EGF level were detected by enzyme-linked immunosorbent assay (ELISA). And then the levels of urinary MCP-1, EGF and the ratio of EGF/MCP-1 and their correlations with clinicopathology were analyzed. Results: There was no statistical difference of the urine EGF levels between the two groups [8.3(6.0,12.6) vs 8.4(6.5,10.2) ng/mg Cr, P=0.575]. The urine MCP-1 levels of IMN patients were 0.37 (0.21, 0.69) ng/mg Cr, which was statistical significantly higher than those of the control group [0.09 (0.02, 0.19) ng/mg Cr] (P<0.001), while the EGF/MCP-1 ratio was lower than that of the control group [22.2(15.1,36.6) vs 87.6(71.2,132.7), P<0.001]. Urine MCP-1 was negatively correlated with eGFR (r=-0.303, P=0.012), but positively correlated with the urinary ratio of albumin to creatinin (r=0.368, P=0.002). EGF was positively correlated with eGFR (r=0.722, P<0.001), but negatively correlated with the severity of interstitial fibrosis and renal tubular atrophy (IFTA) (r=-0.312, P=0.011). EGF/MCP-1 ratio was positively correlated with eGFR (r=0.693, P<0.001), but negatively correlated with the severity of the urinary ratio of albumin to creatinin and IFTA (r=-0.261, P=0.028 and r=-0.684, P<0.001, respectively). Further multivariate logistic regression analysis showed that EGF/MCP-1 was a protective factor for moderate-to-severe IFTA (OR=0.891, 95%CI: 0.844-0.949, P=0.008). Conclusion: Patients with IMN have elevated urine MCP-1 level and decreased EGF/MCP-1 ratio, which correlate with clinical indicators. In particular, EGF/MCP-1 ratio is independently related to moderate-severe IFTA, and may be a potential clinical biomarker for diagnosis of IMN.

Does dual-energy CT differentiate benign and malignant ovarian tumours?

AIM

To assess the ability of dual-energy computed tomography (DECT) to distinguish benign from malignant ovarian tumours (OTs).

MATERIALS AND METHODS

Following approval of the institutional review board, the institutional database was mined for treatment-naive patients who underwent primary cytoreduction for OT. Thirty-seven patients were included and divided into those with benign OTs (n = 11) and malignant OTs (n = 26), including high-grade (n = 20) and low-grade (n = 6) malignant OTs. Advanced processing and region of interest delineation on the ovarian mass were performed using the preoperative staging DECT examination using the Advantage Workstation. The pixel-level data of the CT attenuation values at 50, 70, and 120 keV and the effective atomic number (Z_eff), water content (WC), and iodine content (IC) in the ovarian mass were recorded. The Wilcoxon rank-sum test was used to compare CT attenuation data at different voltages, Z_eff, and WC and IC levels between benign and malignant OTs and between high- and low-grade malignant OTs. Simple logistic regression was used to correlate the imaging characteristics with malignant status and grade.

RESULTS

Malignant OTs had significantly higher Z_eff and IC compared with benign OTs. The threshold values for the diagnosis of malignant OT were IC≥9.74 (100 μg/cm³) with 81% sensitivity and 73% specificity and Z_eff ≥8.16 with 85% sensitivity and 73% specificity. High-grade OTs had significantly higher WC compared with low-grade OTs, and a threshold of ≥1,013.92 mg/cm³ differentiated them with 80% sensitivity and 83% specificity.

CONCLUSION

DECT may be a tool to help distinguish malignant and benign OTs and predict tumour grade.

Gamma-aminobutyric acid enhances tolerance to iron deficiency by stimulating auxin signaling in cucumber (Cucumis sativusL.)

Iron deficiency severely affects crop yield and quality. Gamma-aminobutyric acid (GABA) plays a vital role in plant responses to multifarious stresses. However, the role of GABA in Fe deficiency responses and the potential mechanisms remain largely unknown in cucumber. Here, we found that Fe deficiency raised the GABA levels in leaves and roots of cucumber. To probe the role of GABA in Fe deficiency, the seedlings were subjected to five levels of GABA concentrations (0, 5, 10, 20 and 40 mmol L^-1) for 7 days under Fe deficiency. The results demonstrated that 20 mM GABA in alleviating the Fe deficiency-induced stress was the most effective. GABA pretreatment reduced the Fe deficiency-induced chlorosis and inhibition of photosynthesis and growth, and significantly enhanced the contents of iron in shoots and roots. Exogenous GABA significantly decreased the pH of nutrient solution and increased ferric-chelate reductase (FCR) activity induced by Fe deficiency and the transcript levels of Fe uptake-related genes HA1, FRO2 and IRT1 in roots. GABA also increased the content of auxin (IAA) and expression of auxin biosynthesis (YUC4), response (IAA1), and transport (PIN1) genes under Fe deficiency. Furthermore, exogenous the auxin transport inhibitor 1-naphthylphthalamic acid (NPA) application abolished the GABA-induced changes in Fe deficiency. In summary, we found that GABA improves tolerance to iron deficiency via an auxin-dependent mechanism in cucumber.

20-Hydroxyecdysone receptor-activated Bombyx mori CCAAT/enhancer-binding protein gamma regulates the expression of BmCBP and subsequent histone H3 lysine 27 acetylation in Bo. mori

Cyclic adenosine monophosphate (cAMP) response element binding protein (CREB)-binding protein (CBP or CREBBP) plays important roles in regulating gene transcription and animal development. However, the process by which CBP is up-regulated to impact insect development is unknown. In this study, the regulatory mechanism of Bombyx mori CBP (BmCBP) expression induced by 20-hydroxyecdysone (20E) was investigated. In the Bo. mori cell line, DZNU-Bm-12, 20E enhanced BmCBP transcription and histone H3K27 acetylation. BmCBP RNA interference (RNAi) resulted in decreased histone H3K27 acetylation. Additionally, the luciferase activity analysis revealed that the transcription factor, Bo. mori CCAAT/enhancer-binding protein gamma (BmC/EBPg), activated BmCBP transcription, which was suppressed by BmC/EBPg RNAi and promoted by BmC/EBPg overexpression. Electrophoretic mobility shift assay and chromatin immunoprecipitation results demonstrated that BmC/EBPg could bind to the C/EBP cis-regulatory elements in two positions of the BmCBP promoter. Moreover, BmC/EBPg transcription was enhanced by the 20E receptor (BmEcR), which bound to the BmC/EBPg promoter. BmEcR RNAi significantly inhibited the transcriptional levels of BmC/EBPg and BmCBP in the presence of 20E. Furthermore, the BmEcR-BmC/EBPg pathway regulated the acetylation levels of histone H3K27. Altogether, these results indicate that BmEcR enhances the expression of BmC/EBPg, which binds to the BmCBP promoter, activates BmCBP expression and leads to histone H3K27 acetylation.

Estimation of error variance via ridge regression

We propose a novel estimator of error variance and establish its asymptotic properties based on ridge regression and random matrix theory. The proposed estimator is valid under both low- and high-dimensional models, and performs well not only in nonsparse cases, but also in sparse ones. The finite-sample performance of the proposed method is assessed through an intensive numerical study, which indicates that the method is promising compared with its competitors in many interesting scenarios.

Determination of Glyphosate and Aminomethylphosphonic Acid in Crops by Capillary Gas Chromatography with Mass-Selective Detection: Collaborative Study

A collaborative study was conducted to validate a method for the determination of glyphosate and aminomethylphosphonic acid (AMPA) in crops. The analytes are extracted from crops with water, and the crude extracts are then subjected to a cation exchange cleanup. The analytes are derivatized by the direct addition of the aqueous extract into a mixture of heptafluorobutanol and trifluoroacetic anhydride. The derivatized analytes are quantitated by capillary gas chromatography with mass-selective detection (MSD). The collaborative study involved 13 laboratories located in 5 countries 12 laboratories returned valid data sets. The crops tested were field corn grain, soya forage, and walnut nutmeat at concentrations of 0.050, 0.40, and 2.0 mg/kg. The study used a split-level pair replication scheme with blindly coded laboratory samples. Twelve materials were analyzed, including 1 control and 3 split-level pairs for each matrix, 1 pair at each nominal concentration. For glyphosate, the mean recovery was 91%, the average intralaboratory variance, the repeatability relative standard deviation (RSDr), was 11%, and the interlaboratory variance, the reproducibility relative standard deviation (RSDR), was 16%. For AMPA, the mean recovery was 87%, the RSDr was 16%, and the RSDR was 25% at mg/kg levels.

Correction: S Zheng. Radiological progression of penicillin-sensitive Staphylococcus aureus aortitis

[This corrects the article DOI: 10.12809/hkmj187616].

Surgical repair of traumatic cloaca: a modified technique

AIM

A modified repair technique for traumatic cloaca caused by obstetric anal sphincter injury was evaluated, and its feasibility and functional outcome were investigated.

METHODS

A retrospective review of 23 consecutively enrolled patients diagnosed with traumatic cloaca who underwent the modified repair technique between September 2010 and August 2018 was performed. Demographic, clinical feature, operative and follow-up data were recorded.

RESULTS

The patients diagnosed with traumatic cloaca who underwent surgical repair after obstetric anal sphincter injury had a median time from obstetric injury of 24 (12-35) years. The median preoperative Wexner faecal incontinence score was 16 (14-17). The postoperative hospital stay was 6 (6-7) days. The median postoperative Wexner faecal incontinence score decreased to 2 (2-3). The anal resting pressure increased from 9.00 (5.25-11.50) mmHg to 56.00 (55.00-65.75) mmHg (P < 0.01) and the anal squeeze pressure increased from 29.00 (22.50-33.20) mmHg to 110.00 (96.20-121.50) mmHg (P < 0.01) at 2 months after the repair. Sixteen patients completed the Faecal Incontinence Quality of Life Scale questionnaire, and there were significant improvements 1 year after surgical repair in lifestyle (3.10 [2.60-3.70] vs 2.60 [1.90-3.00], P < 0.01), coping/behaviour (3.38 [2.57-3.44] vs 2.33 [1.89-3.00], P < 0.01), depression/self-perception (3.11 [2.27-3.44] vs 2.33 [1.89-3.00], P < 0.01) and embarrassment (3.33 [2.75-3.67] vs 2.33 [2.33-3.00], P < 0.01). No patient presented rectovaginal fistula postoperatively within the median follow-up period of 24 (12-48) months.

CONCLUSIONS

The modified repair technique for traumatic cloaca is feasible and achieves good functional outcomes and improved life quality.

Testosterone propionate can promote effects of acellular nerve allograft-seeded bone marrow mesenchymal stem cells on repairing canine sciatic nerve

Peripheral human nerves fail to regenerate across long tube implants (>2 cm), and tissue-engineered nerve grafts represent a promising treatment alternative. The present study aims to investigate the testosterone propionate (TP) repair effect of acellular nerve allograft (ANA) seeded with allogeneic bone marrow mesenchymal stem cells (BMSCs) on 3-cm canine sciatic nerve defect. ANA cellularized with allogeneic BMSCs was implanted to the defect, and TP was injected into the lateral crus of the defected leg. The normal group, the autograft group, the ANA + BMSCs group, the ANA group, and the nongrafted group were used as control. Five months postoperatively, dogs in the TP + ANA + BMSCs group were capable of load bearing, normal walking, and skipping, the autograft group and the ANA + BMSCs group demonstrated nearly the same despite a slight limp. The compound muscle action potentials (CMAPs) on the injured side to the uninjured site in the TP + ANA + BMSCs group were significantly higher than that in the ANA + BMSCs group [CMAPs ratio at A: F(3, 20) = 191.40; 0.02, CMAPs ratio at B: F(3, 20) = 43.27; 0.01]. Masson trichrome staining revealed that in the TP + ANA + BMSCs group, both the diameter ratio of the myelinated nerve and the thickness ratio of regenerated myelin sheath were significantly larger than that in the other groups [the diameter of myelinated nerve fibers: F(3, 56) = 13.45; P < .01, the thickness ratio of regenerated myelin sheath: F(3, 56) = 51.25; P < .01]. In conclusion, TP could significantly increase the repairing effects of the ANA + BMSCs group, and their combination was able to repair 3-cm canine sciatic nerve defect. It therefore represents a promising therapeutic approach.

Abstract P3-03-20: Which biopsy is preferred to stage the axilla under ultrasound guidance in early breast cancer patients: Fine-needle aspiration cytology or core needle biopsy?

Background:

Preoperative axillary ultrasound (AUS) offers the potential to identify clinically axillary negative patients with axillary lymph node (ALN) metastasis directly to axillary lymph node dissection (ALND) with avoid of unnecessary sentinel lymph node biopsy (SLNB) except Z0011 candidates. Which biopsy should be preferred is pendent with lack of enough prospective studies. The purpose of our study was to compare the accuracy of ultrasound guided fine-needle aspiration cytology (FNAC) and core needle biopsy (CNB) for the designated ALN prospectively.

Methods:

Consecutive patients with histologically confirmed breast cancer from April, 2010 to December, 2014 were preliminary screened for our study. All the candidate patients were prospectively assessed by ipsilateral AUS before initial treatment regardless of clinical ALN status.Abnormal lymph nodes were characterized by round shape with uniform or eccentric thickening, focal bulging or irregularity of the cortex displacement, obliteration of the hilum; or total loss of recognizable lymph node architecture. If suspicious ALN was identified, both ultrasound-guided FNAC and CNB were performed for the same designated ALN.The diameter in longitudinal section, transverse section and maximum cortical thickness of the target node was recorded. When more than one abnormal lymph node was present, the most abnormal-appearing node was sampled. The target tissue for biopsy was hypoechoic thickened cortex. Patients with a positive FNAC/CNB underwent ALND, and those with a negative FNAC and CNB biopsy or without suspicious ALN by AUS underwent SLNB. The paired parameters of FNAC and CNB were compared using McNemar's exact test.

Results:

705 consecutive patients were screened and 558 patients (561 axillae) underwent AUS evaluation with confirmed ALN pathological results.145 patients (146 axillae) with both FNAC and CNB were finally enrolled. Final histopathological results showed that 83.6% (122/146) were node positive (5 micro-metastases were considered negative). Sensitivity of FNAC and CNB was 67.2% (82/122) and 91.8% (112/122). Overall accuracy of FNAC and CNB was 72.6% (106/146) and 93.2% (136/146). Negative predictive value (NPV) of FNAC and CNB was 37.5% (24/64) and 70.6% (24/34). There was significant difference in sensitivity, overall accuracy and NPV between FNAC and CNB (p&lt;0.001). 80.6% (29/36) FNAC negative and CNB positive patients have ALN cortical thickness of 3.3-7.2 mm.

Conclusion:

CNB is more sensitive and accurate than FNAC to stage the axilla under ultrasound guidance in operable breast cancer patients, especially in patients with ALN cortical thickness of 3.3-7.2 mm.

Citation Format: Zhou M, Qiu J, Chen J, Hu Y, Deng Y, Zheng S. Which biopsy is preferred to stage the axilla under ultrasound guidance in early breast cancer patients: Fine-needle aspiration cytology or core needle biopsy? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-20.

Associations between serum S100A8/S100A9 and knee symptoms, joint structures and cartilage enzymes in patients with knee osteoarthritis

OBJECTIVE

Animal studies suggest that S100A8/S100A9 may be involved in the pathogenesis of osteoarthritis (OA); however, there has been no clinical study examining the associations between serum S100A8/S100A9 and knee symptoms, joint structures and cartilage degradation enzymes in knee OA patients so far. Therefore, this study was designed to investigate the cross-sectional associations between serum levels of S100A8/S100A9 and the outcomes in patients with knee OA.

DESIGN

A total of 141 subjects with clinical knee OA were included. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was used to assess joint symptoms. Magnetic resonance imaging (MRI) was used to measure knee structural abnormalities including cartilage defects. Knee radiography was used to assess joint space narrowing (JSN), osteophytes and the radiographic severity of OA. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum levels of S100A8/S100A9, matrix metalloproteinase (MMP)-3, MMP10 and MMP13.

RESULTS

In multivariable analyses, serum S100A8/S100A9 were positively associated with total WOMAC score (β: 0.111 per 10 ng/ml, P = 0.021), WOMAC weight-bearing pain (β: 0.015 per 10 ng/ml, P = 0.043) and WOMAC physical dysfunction (β: 0.091 per 10 ng/ml, P = 0.010), and had positive associations with total cartilage defects and cartilage defects at lateral femoral, lateral tibial and medial femoral sites (ORs: 1.006-1.008 per 10 ng/ml, all P < 0.05) and serum levels of MMP3 (β: 0.002 per 10 ng/ml, P = 0.032) in patients with clinical knee OA.

CONCLUSIONS

Serum levels of S100A8/S100A9 were positively associated with increased knee symptoms, cartilage defects and serum cartilage degradation enzymes in patients with knee OA, suggesting that S100A8/S100A9 may have a role to play in knee OA. Future longitudinal studies are required to confirm these findings.

[Current applications of artificial intelligence in tumor histopathology]

The tasks of artificial intelligence (AI) in tumor histopathology include image segmentation and classification. Currently, the specific contents including lymph node metastasis, pathological classification, grade and prognostic evaluation of malignant diseases, such as breast cancer, lung cancer and prostate cancer, have been studied by AI. Evaluation of sentinel lymph node metastasis of breast cancer has been the most mature application of AI technology, whose level can be analogous to the excellent pathologists. In the future, with the close cooperation of pathologists and engineers, the research of AI will be focus on improving the technology of simple and repetitive clinical diagnosis and differential diagnosis, such as the diagnosis of sentinel lymph node metastasis of breast cancer from biopsy frozen section and the judgment of incisal margin. Ultimately, AI will help us to precisely diagnose the tumor.

A novel method for assessing proximal tibiofibular joint on MR images in patients with knee osteoarthritis

OBJECTIVES

To validate a method to measure the morphological parameters of the proximal tibiofibular joint (PTFJ) in patients with knee osteoarthritis (OA).

METHODS

408 participants were examined in this cross-sectional subject-based study. We calculated the fibular contacting area of PTFJ (S) and its projection areas onto the horizontal plane (load-bearing area, Sτ), the sagittal plane (lateral stress-bolstering area, Sφ) and the coronal plane (posterior stress-bolstering area, Sυ). Joint space narrowing (JSN) and osteophyte was measured using radiographs. Cartilage defects, bone marrow lesions (BMLs) and cartilage volume were evaluated using magnetic resonance imaging (MRI).

RESULTS

The average PTFJ fibular contacting area was 2.4 cm² (SD, ±0.7 cm²). Intra-observer and inter-observer reliabilities of measures of PTFJ morphological parameters were excellent (≥0.90). S, Sτ and Sφ were significantly associated with JSN in the medial tibiofemoral compartment (PR: 1.40, 95% CI 1.10-1.78; PR: 1.65, 95% CI 1.25-2.18 and PR: 0.53, 95% CI 0.29-0.97, respectively). There was a significantly positive association between S, Sτ and medial and/or femoral tibial cartilage defects. S, Sτ and Sυ were significantly and positively associated with medial and/or femoral tibial BMLs (PR: 1.36, 95% CI 1.12-1.64; PR: 1.47, 95% CI 1.17-1.83; and PR: 1.39, 95% CI 1.06-1.82, respectively) after adjustment. S and Sτ were significantly and negatively associated with medial tibial cartilage volume.

CONCLUSIONS

This novel method to assess the morphological parameters of PTFJ in MRI is reproducible. These parameters are associated with knee radiographic and MRI-based OA-related structural abnormalities, suggesting clinical construct validity. Its predictive validity needs to be examined in future longitudinal studies.

[Abuse of diphenoxylate and related factors of forced drug abstainer in Gansu province]

Objective: To investigate the prevalence of diphenoxylate abuse and related factors of forced drug abstainer in Gansu province. Methods: By using a self-designed questionnaire, an epidemiologic investigation was carried out among 2 108 forced drug abstainer selected from the compulsory isolation detoxification center of Gansu province. A case-control study was conducted to analyze the factors related with diphenoxylate abuse. Results: The diphenoxylate abuse rate among forced drug abstainer in Gansu was 19.8% (406/2 046), ranking first in medical drug abuse. Multiple logistic regression analysis showed that factors as relieving withdrawal symptoms (OR=2.08, 95%CI: 1.01- 4.32), ways to obtain diphenoxylate (other ways: OR=1.00; regular clinic: OR=27.67, 95%CI: 2.64-289.82; friend: OR=0.01, 95%CI: 0.01-0.03), degree of euphoria (high: OR=1.00; medium: OR =3.36, 95%CI: 1.18-9.55; low: OR=26.16, 95%CI: 10.30-66.42), years of drug abuse (<5 years: OR=1.00; 10-15 years: OR=2.48, 95%CI: 1.02-6.04), abuse at home or in friend's house (OR=3.04, 95%CI: 1.08-8.68), abuse in car (OR=0.05, 95%CI: 0.00-0.68) and detoxification for the first time (OR=0.61, 95%CI: 0.43-0.86) were the possible influencing factors for diphenoxylate abuse. Conclusions: The prevalence of diphenoxylate abuse in forced drug abstainer in Gansu was relatively high. Reasons of abusing, the way to obtain diphenoxylate, whether using drug together with friends, degree of euphoria, years of abuse, abuse place and times for detoxification were related factors influencing the abuse of diphenoxylate.

Nuclear factor erythroid-derived 2-related factor 2 activates glutathione S-transferase expression in the midgut of Spodoptera litura (Lepidoptera: Noctuidae) in response to phytochemicals and insecticides

Detoxication enzymes play an important role in insect resistance to xenobiotics such as insecticides and phytochemicals. We studied the pathway for activating the expression of glutathione S-transferases (GSTs) in response to selected xenobiotics. An assay of the promoter activity of GST epsilon 1 (Slgste1) of Spodoptera litura led to the discovery of a cis-regulating element. An antioxidant response element was activated in response to indole-3-carbinol (I3C) and chlorpyrifos (CPF) and was able to bind with the xenobiotic sensor protein nuclear factor erythroid-derived 2-related factor 2 (SlNrf2). SlNrf2 and Slgste1 were responsive to reactive oxygen species induced by I3C and CPF in a S. litura cell line, as well as in S. litura midguts. SlNrf2 RNA interference (RNAi) reduced the message RNA levels of Slgste1 and the peroxidase activity of GSTs in response to I3C, xanthotoxin, CPF and deltamethrin. SlNrf2 RNAi and inhibitor treatment of GST activity decreased the viability of I3C-treated cells. These results indicate that SlNrf2 activates the expression of GSTs in response to oxidative stresses caused by exposure to xenobiotics.