Deep Learning for Automatic Prediction of Lymph Node Station Metastasis in Esophageal Cancer Patients from Contrast-Enhanced CT

PURPOSE/OBJECTIVE(S)

The diagnosis of lymph node (LN) metastasis in computed tomography (CT) is an essential yet challenging task in esophageal cancer staging and treatment planning. Although criteria (e.g., RECIST, morphological/texture features) are proposed to predict LN metastasis, the diagnostic accuracy remains low with sensitivity <50% and specificity <75%, as reported in previous studies. Deep learning (DL) has the potential to address this issue by learning from large-scale labeled data. However, due to the practical surgery procedure in lymph node dissection, it is difficult to pair the metastasis of individual LN reported in the pathology report to the LN instance found in the CT image. Hence, in this study, we first use pathology reports to determine the LNS metastasis, then develop a multiple instance deep learning (MIDL) model to predict lymph node station (LNS) metastasis.

MATERIALS/METHODS

We collected 1200 esophageal cancer patients with preoperative contrast-enhanced CT before surgery. A recently developed automatic mediastinal LNS segmentation model was first applied to segment LNS of 1 to 8 based on the IASLC protocol. For each LNS, the local CT region of interest (ROI) was cropped to generate a station-wise CT patch, where the LNS was labeled as metastatic if at least one metastatic LN was indicated in the pathology report. Using the station-wise CT patch and LNS label, we train a 3D MIDL model, MobileNetV3, to predict LNS metastasis. To better provide the LN position priors in MIDL, LN instances (with a short axis >4mm) were also segmented using an automatic LN detection algorithm and were added to the MIDL model as an auxiliary input. Five-fold cross-validation was conducted to evaluate the MIDL performance.

RESULTS

The MIDL model's performance is summarized in Table 1. The MIDL model incorporating an additional LN instance mask demonstrated a superior overall AUC of 0.7539, surpassing the model without the LN mask input by 2.93%. The specificity was evaluated at a threshold resulting in a recall of 0.7, and the best model outperformed the CT input model in terms of specificity by 2.11%. This highlights the value of including the LN position prior to the MIDL model. Notably, when a threshold was set to result in a specificity of 75%, the best MIDL model demonstrated a significantly higher recall compared to the previously reported clinical diagnostic recall (39.7% vs. 63.21%).

CONCLUSION

We developed a MIDL classification model to predict LNS metastasis using CT scans of 1200 patients. Our findings suggest that the MIDL model can substantially improve LNS metastasis prediction and has the potential to play an essential role in cancer staging, treatment planning, and prognostic analysis.

[Acceptance of pre-exposure prophylaxis and post-exposure prophylaxis against HIV and related factors in men who have sex with men in Shandong Province]

Objectives: To understand the use of pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) and related factors in men who have sex with men (MSM) in Shandong Province, and provide reference for the promotion of PrEP and PEP in MSM. Methods: From April to July in 2022, MSM were recruited from 7 sentinel surveillance sites in Shandong Province for a questionnaire survey, and the sample size of each city site was 400. The information about sociodemographic characteristics, sexual behaviors, the uses of PrEP and PEP and others were collected from the MSM, and blood samples were collected from them for HIV and syphilis testing. Results: A total of 2 815 MSM were investigated, the majority of them were aged less than 30 years (55.7%, 1 569/2 815), unmarried (68.6%, 1 931/2 815) and had education background of college and above (56.5%, 1 590/2 815). Only 9.2% (258/2 815) had used PrEP and 10.8% (305/2 815) had used PEP. Multivariate logistic regression showed that factors associated with high likelihood of PrEP use in MSM included age ≤30 years (aOR=4.04, 95%CI:1.25-13.01), self-perceived lower risk of HIV infection (aOR=1.76, 95%CI:1.16-2.68), group sex and commercial sex in the past six months (aOR=1.51, 95%CI: 1.10-2.09; aOR=1.69, 95%CI: 1.16-2.47), new-type drug use (aOR=1.53, 95%CI: 1.11-2.11), receiving peer education (aOR=1.56, 95%CI: 1.03-2.37), other people using PrEP (aOR=3.29, 95%CI: 2.48-4.36), and being HIV negative (aOR=8.40, 95%CI:1.12-63.12). Factor associated with low likelihood of PrEP use in MSM was anal sex with casual partner (aOR=0.67, 95%CI:0.49-0.90). Factors associated with high likelihood of PEP use in MSM included age under 50 years (≤30 years old: aOR=2.41, 95%CI:1.02-5.69; 31-49 years old: aOR=3.33, 95%CI:1.42-7.85), no self-perceived risk for HIV infection (aOR=1.87, 95%CI:1.12-3.11), group sex in the past six months (aOR=1.68, 95%CI:1.23-2.29), new-type drug use (aOR=3.86, 95%CI:2.94-5.07) and receiving no peer education (aOR=1.54, 95%CI:1.12-2.12). Conclusions: In Shandong, a higher proportion of MSM used PrEP and PEP. Peer education and self-perceived HIV infection risk education should be strengthened to increase the rates of PrEP and PEP use in MSM.

Can the mouse model successfully predict mixed metal(loid)s bioavailability in humans from contaminated soils?

Mouse models have been employed by many scientific research groups worldwide to predict the bioavailability of metal (loid)s and other chemicals in humans. Their suitability for predicting mixed metal (loid) bioavailability has been questioned and debated for decades by many research teams. In this study soils contaminated by lead (Pb) and arsenic (As), either in the field or by spiking in the laboratory, were used in bioavailability and bioaccessibility tests. The spiked soils were aged for more than a year prior to testing to achieve steady state and eliminate soil ageing effects, as reported in previous research. The bioavailability of, firstly, Pb in the presence of As and secondly, As in the presence of Pb was determined using mice. Furthermore, bioaccessibility was determined using a range of in vitro methods: relative bioaccessibility leaching procedure (RBALP), the Unified Bioaccessibility Research Group Europe (BARGE) method (UBM) gastric and intestinal phases, and the National Institute for Public Health and the Environment (RIVM) gastric and intestinal phases. The correlations between Pb and As bioavailability and their in vitro bioaccessibility when they were present in mixtures were analysed. The results indicated that the bioavailability of Pb in mice kidney tissues significantly correlated with bioaccessibility of Pb in RBALP (p < 0.01), UBM gastric (p < 0.01) and intestinal phases (p < 0.01) and RIVM gastric phases when Pb is present in metal (loid) mixtures. Results of the current study reveal that the RBALP, and UBM gastric and intestinal phase were by far the best methods for predicting the RB of Pb when it is present in metal (loid) mixtures. Consequently, the mouse model can successfully explain the in vivo in vitro correlation (IVIVC) of Pb when it is present in metal (loid) mixtures. However, we did find that a mouse model may not be the best one to explain the IVIVC of As when it is present in metal (loid) mixtures.

[Clinical characteristics of 16 neonates infected with SARS-CoV-2 during Omicron variant outbreak]

Objective: To analyze the clinical characteristics of the neonates infected with SARS-CoV-2 during the Omicron outbreak in Shanghai 2022. Methods: In this retrospective case series study, all the 16 neonates with SARS-CoV-2 Omicron infection who were admitted to the neonatal unit in Shanghai Public Health Clinical Center from March 1^st to May 31^st, 2022 were enrolled. Their epidemiological history, clinical manifestations, nucleic acid cycle threshold (Ct) value and outcomes were analyzed. Based on maternal vaccination, they were divided into vaccinated group and unvaccinated group. Rank sum test and Chi-square test were used for the comparison between the groups. Results: Among the 16 neonates, 10 were male, and 6 were female. All the infants were full-term. The infection was confirmed at the age of 12.5 (8.0, 20.5) days. All the neonates had a history of exposure to infected family members, and thus horizontal transmission was the primary mode. Four infants were asymptomatic, 12 were symptomatic, and there were no severe or critical cases. The most common clinical manifestation was fever (11 cases), with the highest temperature of 38.1 (37.9, 38.3) ℃ and a course of 1-5 days. Other clinical manifestations included nasal obstruction (3 cases), runny nose (2 cases), cough (2 cases), poor feeding (2 cases), vomiting (1 case), and mild tachypnea (1 case). The complete blood counts of all neonates were within the normal range, and the C-reactive protein increased slightly in 1 infant. Chest imaging was performed in 2 infants, showing mild focal exudative changes. Nucleic acid turned negative (Ct value ≥35) within 7-15 days after diagnosis. All neonates fully recovered after supportive treatment, and the length of hospitalization was 13 (10, 14) days. In the telephone follow-up 2 weeks after discharge for all 16 cases, no infant showed reoccurrence of clinical manifestations or nucleic acid reactivation. Maternal vaccination was not significantly correlated with symptomatic infection or the persistence of positive nucleic acid result in neonates (all P>0.05). Conclusions: Horizontal transmission is the primary mode for neonatal SARS-CoV-2 Omicron infection. Neonatal infections are usually mild or asymptomatic, with good short-term outcomes. And their clinical manifestations and laboratory examinations are nonspecific.

[Management and short-term outcomes of neonates born to mothers infected with SARS-CoV-2 Omicron variant]

Objective: To summarize the management and short-term outcomes of neonates delivered by mothers infected with SARS-CoV-2 Omicron variant. Methods: A retrospective study was performed on 158 neonates born to mothers infected with SARS-CoV-2 Omicron variant admitted to the isolation ward of Children's Hospital of Fudan University from March 15^th, 2022 to May 30^th, 2022. The postnatal infection control measures for these neonates, and their clinical characteristics and short-term outcomes were analyzed. They were divided into maternal symptomatic group and maternal asymptomatic group according to whether their mothers had SARS-CoV-2 symptoms. The clinical outcomes were compared between the 2 groups using Rank sum test and Chi-square test. Results: All neonates were under strict infection control measures at birth and after birth. Of the 158 neonates, 75 (47.5%) were male. The gestational age was (38⁺³±1⁺³) weeks and the birth weight was (3 201±463)g. Of the neonates included, ten were preterm (6.3%) and the minimum gestational age was 30⁺¹ weeks. Six neonates (3.8%) had respiratory difficulty and 4 of them were premature and required mechanical ventilation. All 158 neonates were tested negative for SARS-COV-2 nucleic acid by daily nasal swabs for the first 7 days. A total of 156 mothers (2 cases of twin pregnancy) infected with SARS-CoV-2 Omicron variant, the time from confirmed SARS-CoV-2 infection to delivery was 7 (3, 12) days. Among them, 88 cases (56.4%) showed clinical symptoms, but none needed intensive care treatment. The peripheral white blood cell count of the neonates in maternal symptomatic group was significantly higher than that in maternal symptomatic group (23.0 (18.7, 28.0) × 10⁹ vs. 19.6 (15.4, 36.6) × 10⁹/L, Z=2.44, P<0.05). Conclusions: Neonates of mothers infected with SARS-CoV-2 Omicron variant during third trimester have benign short-term outcomes, without intrauterine infection through vertical transmission. Strict infection control measures at birth and after birth can effectively protect these neonates from SARS-CoV-2 infection.

[Analysis of related factors of new-type drug use and recent HIV infection among men who have sex with men in Shandong province]

Objective: To understand the related factors of new-type drug use and recent HIV infection among men who have sex with men (MSM), and provide a reference for formulating targeted strategies for HIV/AIDS prevention and control. Methods: MSM were recruited in sentinel surveillance sites of nine cities in Shandong province from April to July 2021, with a sample size of 400 in each city. A face-to-face questionnaire was conducted to collect demographic characteristics, high-risk behaviors, acceptance of HIV intervention services, etc. Blood samples were collected for HIV and syphilis antibodies detection. Limiting-antigen avidity enzyme immunoassay (LAg-Avidity EIA) was used to detect recent HIV infection, and the rate of recent HIV infection was calculated. Results: 3 624 MSM were under study with the following characteristics as: aged (32.70±9.33) years old, the aged 30 and above (59.52%, 2 157/3 624), with high school education or below (55.99%, 2 029/3 624), being unmarried/divorced/widowed (57.70%, 2 091/3 624) and as having homosexual orientation (86.26%, 3 126/3 624) accounted for the more mainly. Of 32.95% (1 194/3 624) had same-sex unprotected anal sex in recent six months; 27.48% (993/3 613) ever used new-type drugs, and the HIV antibody positive rate was 3.12% (113/3 624). The recent HIV infection rate appeared as 2.61% (95%CI: 1.73%-3.49%). The multivariable logistic regression analysis indicated that the related factors of new-type drug use were unmarried/divorced/widowed (compared with being married/cohabitating, aOR=1.43, 95%CI: 1.22-1.69), educational level of college or above (compared with educational level of high school or below, aOR=1.47, 95%CI: 1.25-1.72), mainly through the Internet/dating software to find male sex partners (compared with mainly through bars/baths/parks and other places to find male sex partners, aOR=1.76, 95%CI: 1.41-2.19). Those who had unprotected anal sex in the last six months (compared with no unprotected anal sex, aOR=1.33, 95%CI: 1.13-1.57), had sexually transmitted diseases in the past year (compared with no sexually transmitted disease, aOR=2.77, 95%CI: 2.04-3.76) were more likely to use new-type drugs. The multinominal logistic regression showed that MSM who had unprotected anal sex in the last six months (compared with no unprotected anal sex, aOR=2.51, 95%CI: 1.25-5.01) or did not receive HIV intervention services in the past year (compared with those who received HIV intervention services, aOR=3.89, 95%CI: 1.30-11.60), were syphilis positive (compared with syphilis negative, aOR=8.18, 95%CI: 2.98-22.48), used new-type drugs (compared with those who did not use new-type drugs, aOR=4.75, 95%CI: 2.32-9.70) had a higher risk of recent HIV infection. Conclusions: New-type drugs have been widely used in MSM in Shandong province. The abuse of new-type drugs increases the risk of recent HIV infection.

Clinical outcomes in patients with infrapopliteal arterial occlusive disease treated by lower extremity bypass surgery: a comparison of atherosclerosis and thromboangiitis obliterans

OBJECTIVE

Surgical bypasses are commonly utilized for the treatment of infrapopliteal arterial occlusive disease resulting from atherosclerosis (ASO) and thromboangiitis obliterans (TAO), especially when endovascular procedures fail. The aim of this study is to compare the in-hospital and follow-up outcomes of ASO and TAO patients treated with infrapopliteal bypass surgery.

PATIENTS AND METHODS

A total of 32 infrapopliteal bypasses were analyzed in 18 TAO patients and 14 ASO patients. Preoperative and postoperative arterial Doppler ultrasonography was performed in all patients. The ankle-brachial index (ABI) was calculated preoperatively and postoperatively in all cases. All patients were followed-up for at least one year and clinical outcomes were recorded.

RESULTS

Within 1-7 days postoperatively, 4 grafts in TAO patients occluded; nevertheless, 1 graft occlusion occurred in ASO patients. Patency rates at in-hospital were 77.8% and 92.9% in TAO and ASO patients, respectively. In 27 patients with successful infrapopliteal bypass, ABIs and crural peak arterial flow velocities significantly increased at 1-7 days postoperatively. During the period of follow-up, 6 graft occlusions occurred in TAO patients, and one ASO patient died of myocardial infarction. Patency rates at follow-up were 44.5% and 85.7% in TAO and ASO patients. For TAO patients with graft failure, ABIs at follow-up did not statistically differ from those postoperatively; however, they were significantly higher than those preoperatively.

CONCLUSIONS

Infrapopliteal bypass surgery is a feasible and effective procedure for ASO and TAO patients. Patency rates are lower in TAO than those in ASO during the in-hospital and follow-up period. However, TAO patients had the ischemic symptom relief and the improvement in ABI despite graft occlusion one year postoperatively.

[Development and validation of nomograms for predicting stroke recurrence after firstepisode ischemic stroke]

OBJECTIVE

To explore the risk factors for recurrence in first-episode ischemic stroke survivors and establish a model for predicting stroke recurrence using a nomogram.

METHODS

We collected the data from a total of 821 first-episode ischemic stroke survivors admitted in the Department of Neurology, West China Hospital, Sichuan University from January, 2010 to December, 2018. R software was used for random sampling of the patients, and 70% of the patients were included in the training set to establish the prediction model and 30% were included in the validation set. Cox proportional risk regression model was used to analyze the factors affecting stroke recurrence, and R software rms package was used to construct the histogram and establish the visual prediction model. C-index and calibration curve were used to evaluate the performance of the model for predicting stroke occurrence.

RESULTS

Among the 821 survivors, the recurrence rate was 16.81% at 3 years and 19.98% at 5 years. Multivariate analysis of the training set by Cox regression model showed that an age over 65 years (HR= 2.596, P=0.024), an age of 45-64 years (HR=2.510, P=0.006), a mRS score beyond 3 (HR=2.284, P=0.004) and a history of coronary heart disease (HR=1.353, P=0.034) were all risk factors for stroke recurrence. The C-indexes of the nomogram for the 3-and 5-year relapse prediction model were 0.640 and 0.671, respectively.

CONCLUSION

Age, mRS score and peripheral vascular disease are the factors affecting stroke recurrence in first-episode ischemic stroke survivors, and the nomogram has a high discrimination and predictive power for predicting ischemic stroke recurrence.

A functional genomics screen identifying blood cell development genes in Drosophila by undergraduates participating in a course-based research experience

Undergraduate students participating in the UCLA Undergraduate Research Consortium for Functional Genomics (URCFG) have conducted a two-phased screen using RNA interference (RNAi) in combination with fluorescent reporter proteins to identify genes important for hematopoiesis in Drosophila. This screen disrupted the function of approximately 3500 genes and identified 137 candidate genes for which loss of function leads to observable changes in the hematopoietic development. Targeting RNAi to maturing, progenitor, and regulatory cell types identified key subsets that either limit or promote blood cell maturation. Bioinformatic analysis reveals gene enrichment in several previously uncharacterized areas, including RNA processing and export and vesicular trafficking. Lastly, the participation of students in this course-based undergraduate research experience (CURE) correlated with increased learning gains across several areas, as well as increased STEM retention, indicating that authentic, student-driven research in the form of a CURE represents an impactful and enriching pedagogical approach.

Full Angle Dependence of the Four-Loop Cusp Anomalous Dimension in QED

The angle-dependent cusp anomalous dimension governs divergences coming from soft gluon exchanges between heavy particles, such as top quarks. We focus on the matter-dependent contributions and compute the first truly nonplanar terms. They appear at four loops and are proportional to a quartic Casimir operator in color space. Specializing our general gauge theory result to U(1), we obtain the full QED four-loop angle-dependent cusp anomalous dimension. While more complicated functions appear at intermediate steps, the analytic answer depends only on multiple polylogarithms with singularities at fourth roots of unity. It can be written in terms of four rational structures and contains functions of up to maximal transcendental weight seven. Despite this complexity, we find that numerically the answer is tantalizingly close to the appropriately rescaled one-loop formula, over most of the kinematic range. We take several limits of our analytic result, which serves as a check and allows us to obtain new, power-suppressed terms. In the antiparallel lines limit, which corresponds to production of two massive particles at threshold, we find that the subleading power correction vanishes. Finally, we compute the quartic Casimir contribution for scalars in the loop. Taking into account a supersymmetric decomposition, we derive the first nonplanar corrections to the quark antiquark potential in maximally supersymmetric gauge theory.

[Clinical outcomes of different irradiation ranges in definitive intensity-modulated radiotherapy for esophageal cancer]

Objective: To explore the therapeutic efficacy and safety of elective nodal irradiation (ENI) and involved field irradiation (IFI) in intensity-modulated radiotherapy for esophageal cancer, screen the patients suitable to undergo ENI radiotherapy and provide evidences for individual treatment of esophageal cancer. Methods: A retrospective analysis was performed on the clinical data of 924 patients with esophageal cancer who received definitive intensity-modulated radiotherapy in our hospital from January 2006 to December 2015. Among them, 272 patients received ENI and the other 652 patients received IFI. The clinicopathologic characteristics of 272 cases in ENI group and 652 cases in IFI group, who were recruited according to the balance of propensity score matching method, were compared. The Kaplan-Meier method was used to calculate 1-year, 3-years and 5-years local-regional failure-free survival (LRFFS), progression-free survival (PFS) and overall survival (OS) rates. The univariate and multivariate analysis of prognostic factors were also determined by Cox proportional hazard model and Long-rank test. Results: The clinicopathologic characteristics of these two group were not significantly different (P>0.05). The median follow-up time was 85.9 months and the follow-up rate was 95.9%. The 1-year, 3-years, 5-years PFS rates of the ENI groups were 65.3%, 31.7%, 18.4%, respectively, higher than 54.0%, 20.9%, 12.7% of the IFI group (P=0.001). The 1-year, 3-years, 5-years OS rates of the ENI groups were 79.0%, 43.7%, 24.9%, respectively, higher than 75.0%, 31.8%, 17.2% of the IFI group (P=0.003). In multivariate analysis, the sex, tumor volume, N stage and radiation field were independent factors for PFS and OS (P<0.05). Subgroup analysis showed that patients with male, age≤66 year, cervical and upper-thoracic location, tumor length≤6 cm, T1-2 stage, N0-1 stage, Ⅰ-Ⅱ stage, tumor volume≤50 cm(3), dosage>60 Gy and≤2 cycles of chemotherapy in the ENI group had a better survival rate than those in the IFI group (P<0.05). The total failure rate, local-regional failure rate in ENI group were significantly lower than those of IFI group (P=0.001, P=0.004). The incidence of bone marrow depression≥ grade 2 and 3 in ENI group was higher than that of the IFI group (P<0.05). However, the incidences of radioactive esophagitis≥ grade 3, radioactive pneumonia and late adverse reactions were not significantly different between these two groups (P>0.05). Conclusion: Compared with IFI, ENI can significantly improve the long-term survival for young, early TN stage and cervical/upper-thoracic esophageal cancer patients underwent chemotherapy.

The impacts of gene polymorphisms on methotrexate in Chinese psoriatic patients

BACKGROUND

Methotrexate (MTX) is the first-line treatment for psoriasis in China. The metabolic processes of MTX include various proteins and genes. Previous studies have shown that gene polymorphisms had significant impacts on the efficacy of MTX. However, the influence of gene polymorphisms has not been reported in the Chinese psoriatic patients.

OBJECTIVE

The aim of this study was to verify the impacts of candidate genes polymorphisms on the effectiveness of MTX in a Chinese psoriatic population.

METHODS

In this study, we enrolled 259 psoriasis patients from two clinical centres. Each of them received MTX treatment at 7.5-15 mg/week for at least 8 weeks. Patients were stratified as responders and non-responders according to whether the Psoriasis Area and Severity Index score declined more than 75% (PASI75). According to previous reports, 16 single nucleotide polymorphisms (SNPs) were selected and genotyped for each patient using the Sequenom platform. Fisher's exact test, the chi-square test, Mann-Whitney tests and ANOVA analyses were used for statistical analysis.

RESULTS

Among 259 patients, there were 182 males and 77 females, 63 patients with psoriatic arthritis and 196 patients without arthritis phenotype, and the age of all patients ranged from 19 to 70 years (49.7 ± 13.6). The baseline PASI value of patients was 13.8 ± 8.5, and 33.2% of patients achieved a PASI75 response after MTX treatment. Patients carrying the ATP-binding cassette subfamily B member 1 gene (ABCB1) rs1045642 TT genotype were associated with more severe psoriasis skin lesion (P = 0.032). Furthermore, the ABCB1 rs1045642 TT genotype was found to be more frequent in non-responders (P = 0.017), especially in moderate-to-severe patients (P = 0.002) and patients without psoriatic arthritis (P = 0.026) after MTX treatment.

CONCLUSION

We have demonstrated for the first time that polymorphism of the ABCB1 rs1045642 TT genotype is predictive of a worse clinical response of skin lesions to MTX therapy in a Chinese psoriatic population.

Permissive microbiome characterizes human subjects with a neurovascular disease cavernous angioma

Cavernous angiomas (CA) are common vascular anomalies causing brain hemorrhage. Based on mouse studies, roles of gram-negative bacteria and altered intestinal homeostasis have been implicated in CA pathogenesis, and pilot study had suggested potential microbiome differences between non-CA and CA individuals based on 16S rRNA gene sequencing. We here assess microbiome differences in a larger cohort of human subjects with and without CA, and among subjects with different clinical features, and conduct more definitive microbial analyses using metagenomic shotgun sequencing. Relative abundance of distinct bacterial species in CA patients is shown, consistent with postulated permissive microbiome driving CA lesion genesis via lipopolysaccharide signaling, in humans as in mice. Other microbiome differences are related to CA clinical behavior. Weighted combinations of microbiome signatures and plasma inflammatory biomarkers enhance associations with disease severity and hemorrhage. This is the first demonstration of a sensitive and specific diagnostic microbiome in a human neurovascular disease.

Abstract TMP107: Microbiome Signature of Cerebral Cavernous Malformation Patients

Background: Cerebral cavernous malformation (CCM) patients have lesions comprised of dilated capillaries in the brain. Despite the knowledge that mutations of three CCM genes can cause this disease, other genetic and environmental factors that contribute to lesion formation are likely given the highly variable disease expression. Genome-wide association studies in CCM cohorts and mouse models of CCM, both point to a role of lipopolysaccharide. Mouse studies have shown that the microbiome, particularly Gram-negative bacteria, drive CCM lesion development. These data point to a possibility that CCM disease is affected by the gut microbiome. In this study, we investigated if human CCM disease could be linked to the gut microbiome.

Methods: Fecal samples from 88 CCM patients, from four sites, were assayed using 16S rRNA gene sequencing. Following taxonomic classification by exact sequence variant analysis (ESV) using DeBlur, microbiome composition was compared with those of a reference non-CCM population (n=348), or between subgroups of CCM patients based on clinical data elements.

Results: Analyses of microbiome composition statistics identified bacterial ESVs belonging to Clostridiales , Lachnospiraceae, Ruminococcaceae , and the genus Bacteroides that were significantly enriched in CCM patients compared to healthy controls. Within our CCM cohort, patients with germline CCM mutations had stool-associated enrichment of ESVs annotated to Clostridiales, and the genera Bacteroides and Prevotella , when compared to sporadic CCM patients, while patients with CCM1 and CCM2 mutations had different proportions of Clostridiales, Lachnospiraceae, and the genus Ruminococcus . Furthermore, Lachnospiraceae and Bacteroides proportions differentiated disease aggressiveness (All p<0.05, false discovery rate corrected).

Conclusions: These data are the first to show that CCM patients have a distinct microbiome signature. Germline mutation and disease aggressiveness can correlate with further unique microbiome composition. This study supports further investigation into the mechanistic link between CCM disease and the microbiome. This will enhance our understanding of the brain-gut axis in CCM disease and the use of microbiome as a therapeutic target.

Abstract TP581: Maternal and Fetal Outcomes in Women With Brain Arteriovenous Malformation Rupture During Pregnancy

Background: Intracranial hemorrhage (ICH) is often the initial presenting symptom for patients with brain arteriovenous malformations (bAVM), which is further complicated in the setting of pregnancy. There are no standard guidelines for management of pregnant women with bAVM, and few studies have reported on maternal and fetal outcomes in those with bAVM ICH. The purpose of this descriptive study was to review our case series for maternal and fetal outcomes in women with bAVM ICH during pregnancy.

Methods: We conducted a retrospective review of our database for women between the ages of 15-50 years who presented with a bAVM ICH during pregnancy between 2000-2017. Demographics, angiographic characteristics, gestational age/trimester at ICH, mode and timing of AVM treatment, and maternal (e.g. modified Rankin Scale, mRS) and fetal outcomes (e.g. healthy or intrauterine fetal death) were recorded from the medical records.

Results: We identified 16 bAVM cases who were pregnant at the time of ICH. Mean age of cases was 27±6.7 years, 56% were non-Caucasian, and 81% presented with an ICH during the second or third trimester. Of 16 patients, 2 terminated pregnancies in the 1 st trimester, 1 miscarried immediately after ICH, and 13 patients carried to term (69% delivered cesarean and 23% vaginal). Of 13 patients with live births, 77% received emergent AVM treatment (embolization+resection or resection only) at time of ICH, while 3 deferred treatment until after birth. The majority of bAVMs were Spetzler-Martin grade 2 or 3 (87%), 56% had deep venous drainage, and mean AVM size was 2.5±1.2cm. At 2-year follow-up, 85% of women had good outcomes (mRS 0-2). Only one patient did worse after AVM treatment due to a permanent neurological deficit. All cases had healthy fetal outcomes at time of delivery and at 2-yr follow-up.

Conclusion: Our case series suggest good fetal and maternal outcomes in ruptured bAVM patients presenting during pregnancy, the majority of which were treated before delivery. Treatment of ruptured AVMs during pregnancy should be tailored to the needs of each specific patient in close consultation with the obstetrics and neurosurgery teams.

Heparin-protamine balance after neonatal cardiopulmonary bypass surgery

Essentials Heparin-protamine balance (HPB) modulates bleeding after neonatal cardiopulmonary bypass (CPB). HPB was examined in 44 neonates undergoing CPB. Post-operative bleeding occurred in 36% and heparin rebound in 73%. Thrombin-initiated fibrin clot kinetic assay and partial thromboplastin time best assessed HPB.

SUMMARY

Background Neonates undergoing cardiopulmonary bypass (CPB) are at risk of excessive bleeding. Blood is anticoagulated with heparin during CPB. Heparin activity is reversed with protamine at the end of CPB. Paradoxically, protamine also inhibits blood coagulation when it is dosed in excess of heparin. Objectives To evaluate heparin-protamine balance in neonates undergoing CPB by using research and clinical assays, and to determine its association with postoperative bleeding. Patients/Methods Neonates undergoing CPB in the first 30 days of life were studied. Blood samples were obtained during and after surgery. Heparin-protamine balance was assessed with calibrated automated thrombography, thrombin-initiated fibrin clot kinetic assay (TFCK), activated partial thromboplastin time (APTT), anti-FXa activity, and thromboelastometry. Excessive postoperative bleeding was determined by measurement of chest tube output or the development of cardiac tamponade. Results and Conclusions Of 44 neonates enrolled, 16 (36%) had excessive postoperative bleeding. The TFCK value was increased. By heparin in neonatal blood samples, but was only minimally altered by excess protamine. Therefore, it reliably measured heparin in samples containing a wide range of heparin and protamine concentrations. The APTT most closely correlated with TFCK results, whereas anti-FXa and thromboelastometry assays were less correlative. The TFCK and APTT assay also consistently detected postoperative heparin rebound, providing an important continued role for these long-established coagulation tests in the management of postoperative bleeding in neonates requiring cardiac surgical repair. None of the coagulation tests predicted the neonates who experienced postoperative bleeding, reflecting the multifactorial causes of bleeding in this population.

Methotrexate restores the function of peripheral blood regulatory T cells in psoriasis vulgaris via the CD73/AMPK/mTOR pathway

BACKGROUND

Methotrexate (MTX) is used to treat psoriasis, a chronic inflammatory skin disease.

OBJECTIVES

To investigate the molecular mechanism of MTX in the treatment of psoriasis.

METHODS

Regulatory T cells (Tregs) and effector T (Teff) cells were isolated from the blood of patients with psoriasis and healthy controls. The proliferation of Teff cells was detected by carboxyfluorescein succinimidyl ester assay. The interferon (IFN)-γ and interleukin (IL)-17 levels were analysed by enzyme-linked immunosorbent assay. The expression of CD73 and FoxP3 were determined by flow cytometry. The expression of proteins in the AMPK/mTOR pathway were detected by Western blot analysis.

RESULTS

The data suggested that patients with psoriasis have Tregs with decreased immune suppression function and reduced expression of CD73 compared with healthy controls. Moreover, MTX could significantly restore the immunosuppressive function of IL-17-secreting Tregs. This, in turn, inhibits aberrant proliferation of Teff cells in patients with psoriasis, reverses downregulation of CD73, upregulates phosphorylated AMPK and inhibits phosphorylated mTOR, and downregulates IL-17 and IFN-γ levels.

CONCLUSIONS

We speculate that MTX can restore the immunosuppressive function of Tregs through upregulating CD73, activating AMPK and inactivating the mTOR pathway. These findings may partly explain the mechanism by which MTX treats psoriasis.

Abstract WP427: Health-related Quality of Life Measures in Familial Cerebral Cavernous Malformation Patients

Background: Patient-reported quality of life (QoL) using standardized tools have been proposed as outcome measures in clinical trials. The NeuroQoL scale has been evaluated in patients with common neurological disorders (e.g., ischemic stroke, epilepsy, ALS, and Parkinson’s), but has not been applied to familial cerebral cavernous malformation (FCCM). FCCM is typically characterized by multiple brain lesions that can cause clinical symptoms (hemorrhages, seizures, headaches, neurological deficits) and affect QoL. The purpose of this study was to summarize NeuroQoL domain scores in FCCM patients.

Methods: NeuroQoL short forms covering 12 QoL domains (Figure) were completed by 50 FCCM adults enrolled in the Brain Vascular Malformation Consortium CCM Project. Raw scores summing responses in each domain were converted to T-scores, which are standardized to general (8 domains) or clinical (4 domains) reference populations with mean of 50 and standard deviation of 10. One-sample t-tests were used to determine whether mean T-scores were significantly different from 50 (p<0.05).

Results: We observed significant differences between FCCM and the reference populations on several domains (Figure). Compared to the general reference population, FCCM patients were more likely to have higher positive affect (56, p<0.001) and less depression (55, p<0.001), but lower social satisfaction (48, p=0.032). Compared to the clinical reference population, FCCM patients reported significantly less stigma (61, p<0.001) and less fatigue (54, p=0.018).

Conclusion: FCCM patients differed from the reference populations on several NeuroQoL domains, including positive affect, depression, stigma, fatigue and social satisfaction. Further studies are needed to understand the effect of clinical symptoms on NeuroQoL domains in FCCM.

On the morphological, structural and electrochemical properties of entangled Cu-filled carbon nano-onions

We demonstrate an advanced CVS approach in which the synthesis of Cu-filled carbon nano-onions (CNOs) is achieved by direct sublimation and pyrolysis of a not previously used precursor, namely chloro(1,5-cyclooctadiene)copper(i) dimer.

Ferromagnetically filled carbon nano-onions: the key role of sulfur in dimensional, structural and electric control

A key challenge in the fabrication of ferromagnetically filled carbon nano-onions (CNOs) is the control of their thickness, dimensions and electric properties. Up to now literature works have mainly focused on the encapsulation of different types of ferromagnetic materials including α-Fe, Fe3C, Co, FeCo, FePd3 and others within CNOs. However, no report has yet shown a suitable method for controlling both the number of shells, diameter and electric properties of the produced CNOs. Here, we demonstrate an advanced chemical vapour deposition approach in which the use of small quantities of sulfur during the pyrolysis of ferrocene allows for the control of (i) the diameter of the CNOs, (ii) the number of shells and (iii) the electric properties. We demonstrate the morphological, structural, electric and magnetic properties of these new types of CNOs by using SEM, XRD, TEM, HRTEM, EIS and VSM techniques.

The C-terminal fibrinogen-like domain of angiopoietin-like 4 stimulates adipose tissue lipolysis and promotes energy expenditure

Angptl4 (Angiopoietin-like 4) is a circulating protein secreted by white and brown adipose tissues and the liver. Structurally, Angptl4 contains an N-terminal coiled-coil domain (CCD) connected to a C-terminal fibrinogen-like domain (FLD) via a cleavable linker, and both full-length Angptl4 and its individual domains circulate in the bloodstream. Angptl4 inhibits extracellular lipoprotein lipase (LPL) activity and stimulates the lipolysis of triacylglycerol stored by adipocytes in the white adipose tissue (WAT). The former activity is furnished by the CCD, but the Angptl4 domain responsible for stimulating adipocyte lipolysis is unknown. We show here that the purified FLD of Angptl4 is sufficient to stimulate lipolysis in mouse primary adipocytes and that increasing circulating FLD levels in mice through adenovirus-mediated overexpression (Ad-FLD) not only induces WAT lipolysis in vivo but also reduces diet-induced obesity without affecting LPL activity. Intriguingly, reduced adiposity in Ad-FLD mice was associated with increased oxygen consumption, fat utilization, and the expression of thermogenic genes (Ucp1 and Ppargc1a) in subcutaneous WAT. Moreover, Ad-FLD mice exhibited increased glucose tolerance. Chronically enhancing WAT lipolysis could produce ectopic steatosis because of an overflow of lipids from the WAT to peripheral tissues; however, this did not occur when Ad-FLD mice were fed a high-fat diet. Rather, these mice had reductions in both circulating triacylglycerol levels and the mRNA levels of lipogenic genes in the liver and skeletal muscle. We conclude that separating the FLD from the CCD-mediated LPL-inhibitory activity of full-length Angptl4 reveals lipolytic and thermogenic properties with therapeutic relevance to obesity and diabetes.

An Evidence-based Recommendation for a Standardized Approach to Detecting Metastatic Neuroblastoma in Staging Bone Marrow Biopsies

Neuroblastoma is a common malignant tumor of childhood. Accurate bone marrow (BM) evaluation for metastatic tumor is essential; however, no standardized pathologic workup exists for staging BMs. We examined the diagnostic yield of various BM components and optimal core biopsy (CB) length as part of developing evidence-based recommendations for BM evaluation. After obtaining institutional review board approval, 160 BM biopsies from 50 neuroblastoma patients were retrospectively selected. Hematoxylin and eosin-stained CB and Wright-stained aspirates were scored as positive, negative, or indeterminate. Total/trabecular CB lengths were measured using cellSens software and a DP71 camera (Olympus). Of the 160 BMs, 72 were positive for tumor in any component. Of these, 33 (45.8%) were positive in a single portion of the specimen: 19 CBs and 14 aspirates. Compared with overall diagnosis, sensitivities were as follows: CB 76.3%; aspirate 67.1%; core/aspirate combined 94.7%. Diagnostic CBs had significantly longer trabecular length than nondiagnostic CBs (6.74 mm vs 4.03 mm, P = .006). Positive CBs had longer trabecular space than negative marrows (7.91 mm vs 6.25 mm, P = .002). Nearly 50% of our positive specimens showed diagnostic discordance among the various components examined. However, combining CB and aspirate examination improved sensitivity for tumor detection. We therefore recommend bilateral CBs (>1 cm each) and aspirates for the optimal evaluation of BM for metastatic neuroblastoma.

Molecular genetic analysis of 30 families with Joubert syndrome

Joubert syndrome (JS) is rare recessive disorders characterized by the combination of hypoplasia/aplasia of the cerebellar vermis, thickened and elongated superior cerebellar peduncles, and a deep interpeduncular fossa which is defined by neuroimaging and is termed the 'molar tooth sign'. JS is genetically highly heterogeneous, with at least 29 disease genes being involved. To further understand the genetic causes of JS, we performed whole-exome sequencing in 24 newly recruited JS families. Together with six previously reported families, we identified causative mutations in 25 out of 30 (24 + 6) families (83.3%). We identified eight mutated genes in 27 (21 + 6) Japanese families, TMEM67 (7/27, 25.9%) and CEP290 (6/27, 22.2%) were the most commonly mutated. Interestingly, 9 of 12 CEP290 disease alleles were c.6012-12T>A (75.0%), an allele that has not been reported in non-Japanese populations. Therefore c.6012-12T>A is a common allele in the Japanese population. Importantly, one Japanese and one Omani families carried compound biallelic mutations in two distinct genes (TMEM67/RPGRIP1L and TMEM138/BBS1, respectively). BBS1 is the causative gene in Bardet-Biedl syndrome. These concomitant mutations led to severe and/or complex clinical features in the patients, suggesting combined effects of different mutant genes.

Stalled replication forks within heterochromatin require ATRX for protection

Expansive growth of neural progenitor cells (NPCs) is a prerequisite to the temporal waves of neuronal differentiation that generate the six-layered neocortex, while also placing a heavy burden on proteins that regulate chromatin packaging and genome integrity. This problem is further reflected by the growing number of developmental disorders caused by mutations in chromatin regulators. ATRX gene mutations cause a severe intellectual disability disorder (α-thalassemia mental retardation X-linked (ATRX) syndrome; OMIM no. 301040), characterized by microcephaly, urogenital abnormalities and α-thalassemia. Although the ATRX protein is required for the maintenance of repetitive DNA within heterochromatin, how this translates to disease pathogenesis remain poorly understood and was a focus of this study. We demonstrate that Atrx(FoxG1Cre) forebrain-specific conditional knockout mice display poly(ADP-ribose) polymerase-1 (Parp-1) hyperactivation during neurogenesis and generate fewer late-born Cux1- and Brn2-positive neurons that accounts for the reduced cortical size. Moreover, DNA damage, induced Parp-1 and Atm activation is elevated in progenitor cells and contributes to their increased level of cell death. ATRX-null HeLa cells are similarly sensitive to hydroxyurea-induced replication stress, accumulate DNA damage and proliferate poorly. Impaired BRCA1-RAD51 colocalization and PARP-1 hyperactivation indicated that stalled replication forks are not efficiently protected. DNA fiber assays confirmed that MRE11 degradation of stalled replication forks was rampant in the absence of ATRX or DAXX. Indeed, fork degradation in ATRX-null cells could be attenuated by treatment with the MRE11 inhibitor mirin, or exacerbated by inhibiting PARP-1 activity. Taken together, these results suggest that ATRX is required to limit replication stress during cellular proliferation, whereas upregulation of PARP-1 activity functions as a compensatory mechanism to protect stalled forks, limiting genomic damage, and facilitating late-born neuron production.

Emergency room resource utilization by patients with low-back pain

OBJECTIVE

The objective of this study was to determine factors associated with admission to the hospital through the emergency room (ER) for patients with a primary diagnosis of low-back pain (LBP). The authors further evaluated the impact of ER admission and patient characteristics on mortality, discharge disposition, and hospital length of stay.

METHODS

The authors conducted a retrospective analysis of patients with LBP discharged from hospitals according to the Nationwide Inpatient Sample (NIS) between 1998 and 2007. Univariate comparisons of patient characteristics according to the type of admission (ER versus non-ER) were conducted. Multivariate analysis evaluated factors associated with an ER admission, risk of mortality, and nonroutine discharge.

RESULTS

According to the NIS, approximately 183,151 patients with a primary diagnosis of LBP were discharged from US hospitals between 1998 and 2007. During this period, an average of 65% of these patients were admitted through the ER, with a significant increase from 1998 (54%) to 2005 (71%). Multivariate analysis revealed that uninsured patients (OR 2.1, 95% CI 1.7–2.6, p < 0.0001) and African American patients (OR 1.5, 95% CI 1.2–1.7, p < 0.0001) were significantly more likely to be admitted through the ER than private insurance patients or Caucasian patients, respectively. Additionally, a moderate but statistically significant increase in the likelihood of ER admission was noted for patients with more preexisting comorbidities (OR 1.1, 95% CI 1.0–1.2, p < 0.001). An 11% incremental increase in the odds of admission through the ER was observed with each year increment (OR 1.1, 95% CI 1.0–1.2, p < 0.001). Highest income patients ($45,000+) were more likely to be admitted through the ER (OR 1.3, 95% CI 1.1–1.6, p = 0.007) than the lowest income cohort. While ER admission did not impact the risk of mortality (OR 0.95, 95% CI 0.60–1.51, p = 0.84), it increased the odds of a nonroutine discharge (OR 1.39, 95% CI 1.26–1.53, p < 0.0001).

CONCLUSIONS

A significant majority of patients discharged from hospitals in the US from 1998 to 2007 with a primary diagnosis of LBP were admitted through the ER, with more patients being admitted via this route each year. These patients were less likely to be discharged directly home compared with patients with LBP who were not admitted through the ER. Uninsured and African American patients with LBP were more likely to be admitted through the ER than their counterparts, as were patients with more preexisting health problems. Interestingly, patients with LBP at the highest income levels were more likely to be admitted through hospital ERs. The findings suggest that socioeconomic factors may play a role in the utilization of ER resources by patients with LBP, which in turn appears to impact at least the short-term outcome of these patients.

[Effect of thermo-sensitive Matrigel on minimization of thermal injury to the nearby structures in radiofrequency ablation of subcapsular hepatic tumors in a rat model]

OBJECTIVE

To evaluate the effect and safety of using thermo-sensitive Matrigel as artificial ascites on minimizing thermal injury to the nearby structures in a rat model of radiofrequency (RF) ablation of the liver.

METHODS

In this research, the morphological characterization of Matrigel was observed at different temperatures in vitro. In vivo study was conducted by using 42 SD rats in Matrigel, Saline and control groups of 14 rats each. Artificial ascites with 10 ml of Matrigel or saline was produced under ultrasound guidance before RF in the experimental groups. Using a 0.7 cm exposed 17 G RF electrode for 5 minutes (90 ± 2) ℃, 41 hepatic ablations was performed abutting the diaphragm, abdominal wall and stomach. The 41 rats were sacrificed at 24 h, and necropsy was performed.Gross and histopathologic examinations were performed to compare the frequency and extent of thermal injury to the nearby organs.The animal status was followed up to achieve long term safety evaluation of Matrigel.

RESULTS

Matrigel was in liquid formation at 0-4 ℃, but was not moving in vials at temperature 37 ℃ in 1 min, presenting gel formation.In vivo experiment, the artificial fluid thickness of Matrigel in site was significant larger than that of saline group, especially at 5 min of ablation ((8.1 ± 1.1) mm vs (2.4 ± 0.8)mm, P<0.01). Thermal injury to the nearby structures was found in 12 of 13 cases in control group, 8 of 14 cases (P=0.037) in saline group, and 1 of 14 cases (P<0.01) in Matrigel group. The sizes of the ablation zone of the liver did not differ among the three groups. There was no difference in the incidence of operation related complications among the three groups. There was no significant difference in body weight and health related parameters between Matrigel and saline group during 60 days of follow up.

CONCLUSIONS

Using thermo-sensitive Matrigel as artificial ascites may be a safe and useful technique and help to further reduce the frequency and severity of collateral thermal injury to the nearby structures compare to conventional saline, during RF ablation of subcapsular hepatic tumors.

K63-linked ubiquitination of FANCG is required for its association with the Rap80-BRCA1 complex to modulate homologous recombination repair of DNA interstand crosslinks

DNA interstrand crosslinks (ICLs) are extremely deleterious lesions that are repaired by homologous recombination (HR) through coordination of Fanconi anemia (FA) proteins and breast cancer susceptibility gene 1 (BRCA1) product, but the exact role these proteins have remains unclear. Here we report that FANCG was modified by the addition of lysine63-linked polyubiquitin chains (K63Ub) in response to DNA damage. We show that FANCG K63Ub was dispensable for monoubiquitination of FANCD2, but was required for FANCG to interact with the Rap80-BRCA1 (receptor-associated protein 80-BRCA1) complex for subsequent modulation of HR repair of ICLs induced by mitomycin C. Mutation of three lysine residues within FANCG to arginine (K182, K258 and K347, 3KR) reduced FANCG K63Ub modification, as well as its interaction with the Rap80-BRCA1 complex, and therefore impeded HR repair. In addition, we demonstrated that K63Ub-modified FANCG was deubiquitinated by BRCC36 complex in vitro and in vivo. Inhibition of BRCC36 resulted in increased K63Ub modification of FANCG. Taken together, our results identify a new role of FANCG in HR repair of ICL through K63Ub-mediated interaction with the Rap80-BRCA1 complex.

Value of ecosystem hydropower service and its impact on the payment for ecosystem services

Hydropower is an important service provided by ecosystems. We surveyed all the hydropower plants in the Zagunao River Basin, Southwest China. Then, we assessed the hydropower service by using the InVEST (The Integrated Value and Tradeoff of Ecosystem Service Tools) model. Finally, we discussed the impact on ecological compensation. The results showed that: 1) hydropower service value of ecosystems in the Zagunao River Basin is 216.29 Euro/hm(2) on the average, of which the high-value area with more than 475.65 Euro/hm(2) is about 750.37 km(2), accounting for 16.12% of the whole watershed, but it provides 53.47% of the whole watershed service value; 2) ecosystem is an ecological reservoir with a great regulation capacity. Dams cannot completely replace the reservoir water conservation function of ecosystems, and has high economic and environmental costs that must be paid as well. Compensation for water conservation services should become an important basis for ecological compensation of hydropower development. 3) In the current PES cases, the standard of compensation is generally low. Cascade development makes the value of upstream ecosystem services become more prominent, reflecting the differential rent value, and the value of ecosystem services should be based on the distribution of differentiated ecological compensation.

Genomewide analysis of intronic microRNAs in rice and Arabidopsis

MicroRNAs (miRNAs) are potent regulators of gene transcription and posttranscriptional processes. The majority of miRNAs are localized within intronic regions of protein-coding genes (host genes) and have diverse functions in regulating important cellular processes in animals. To date, few plant intronic miRNAs have been studied functionally. Here we report a comprehensive computational analysis to characterize intronic miRNAs in rice and Arabidopsis. RT-PCR analysis confirmed that the identified intronic miRNAs were derived from the real introns of host genes. Interestingly, 13 intronic miRNAs in rice and two in Arabidopsis were located within seven clusters, of which four polycistronic clusters contain miRNAs derived from different families, suggesting that these clustered intronic miRNAs might be involved in extremely complex regulation in rice. Length analysis of miRNA-carrying introns, promoter prediction and qRT-PCR analysis results indicated that intronic miRNAs are coexpressed with their host genes. Expression pattern analysis demonstrated that host genes had a very broad expression spectrum in different stages of development, suggesting the intronic miRNAs might play an important role in plant development. This comparative genomics analysis of intronic miRNAs in rice and Arabidopsis provides new insight into the functions and regulatory mechanisms of intronic miRNAs in monocots and dicots.

A multi-point laser Doppler vibrometer with fiber-based configuration

Laser Doppler vibrometer (LDV) is a non-contact optical interferometric system to measure vibrations of structures and machines with a high precision. Normal LDV can only offer a single-point measurement. Scanning LDV is usually impractical to do measurement on transient events. In this paper, a fiber-based self-synchronized multi-point LDV is proposed. The multiple laser beams with different frequency shifts are generated from one laser source. The beams are projected onto a vibrating object, reflected and interfered with a common reference beam. The signal including vibration information of multiple spatial points is captured by one single-pixel photodetector. The optical system is mainly integrated by fiber components for flexibility in measurement. Two experiments are conducted to measure a steady-state simple harmonic vibration of a cantilever beam and a transient vibration of a beam clamped at both ends. In the first measurement, a numerical interpolation is applied to reconstruct the mode shape with increased number of data points. The vibration mode obtained is compared with that from FEM simulation. In transient vibration measurement, the first five resonant frequencies are obtained. The results show the new-reported fiber-based multipoint LDV can offer a vibration measurement on various spatial points simultaneously. With the flexibility of fiber configuration, it becomes more practical for dynamic structural evaluation in industrial areas.

Barriers faced by migrants in accessing healthcare for viral hepatitis infection

BACKGROUND

The morbidity and mortality of hepatitis B virus- and hepatitis C virus-related complications are disproportionately higher in the culturally and linguistically diverse population (CALD) when compared with Australian-born individuals.

AIM

This project aims to elucidate the barriers faced by the CALD population in accessing viral hepatitis management.

METHOD

CALD outpatients attending a viral hepatitis clinic in a tertiary teaching hospital were invited to participate in interviews. Questions pertained to: reason for screening for viral hepatitis, barriers to healthcare, perceived community view of viral hepatitis, main source of information of viral hepatitis and suggestions to engage members of CALD to seek healthcare.

RESULTS

The total number of participants was 60. The two major countries of birth included China (40%) and Egypt (17%). In 40% of the cohort, viral hepatitis was identified through screening programmes. Importantly, 37% were diagnosed as a result of complications of hepatitis infection, presenting late in the stage of disease. Forty-five per cent of participants perceived language to be a chief barrier. twenty-two per cent reported cultural barriers to accessing healthcare. Of these, 53% reported fear of discrimination/stigma. The lack of knowledge of available treatments/options was stated as a major obstacle in 40%. The two prevailing recommendations were greater education and awareness (85%) and changes in the health system itself (11%).

CONCLUSION

Substantial hurdles identified by participants include cultural differences, language difficulties, cultural beliefs, stigma and misinformation. These data demonstrate the need for the greater dissemination of information in culturally and linguistically appropriate mediums to raise awareness about viral hepatitis, pathogenesis and available treatments.