Multiomics-assisted characterization of rice-Yellow Stem Borer interaction provides genomic and mechanistic insights into stem borer resistance in rice

KEY MESSAGE

By deploying a multi-omics approach, we unraveled the mechanisms that might help rice to combat Yellow Stem Borer infestation, thus providing insights and scope for developing YSB resistant rice varieties. Yellow Stem Borer (YSB), Scirpophaga incertulas (Walker) (Lepidoptera: Crambidae), is a major pest of rice, that can lead to 20-60% loss in rice production. Effective management of YSB infestation is challenged by the non-availability of adequate sources of resistance and poor understanding of resistance mechanisms, thus necessitating studies for generating resources to breed YSB resistant rice and to understand rice-YSB interaction. In this study, by using bulk-segregant analysis in combination with next-generation sequencing, Quantitative Trait Loci (QTL) intervals in five rice chromosomes were mapped that could be associated with YSB resistance at the vegetative phase in a resistant rice line named SM92. Further, multiple SNP markers that showed significant association with YSB resistance in rice chromosomes 1, 5, 10, and 12 were developed. RNA-sequencing of the susceptible and resistant lines revealed several genes present in the candidate QTL intervals to be differentially regulated upon YSB infestation. Comparative transcriptome analysis revealed a putative candidate gene that was predicted to encode an alpha-amylase inhibitor. Analysis of the transcriptome and metabolite profiles further revealed a possible link between phenylpropanoid metabolism and YSB resistance. Taken together, our study provides deeper insights into rice-YSB interaction and enhances the understanding of YSB resistance mechanism. Importantly, a promising breeding line and markers for YSB resistance have been developed that can potentially aid in marker-assisted breeding of YSB resistance among elite rice cultivars.

WAVE facilitates polarized E-Cadherin transport

Cadherin dynamics drive morphogenesis, while defects in Cadherin polarity contribute to diseases, including cancers. However, the forces polarizing Cadherin membrane distribution are not well understood. We previously showed that WAVE-dependent branched actin polarizes Cadherin distribution, and suggested one mechanism is protein transport. While previous studies suggested that WAVE is enriched at various endocytic organelles, the role of WAVE in protein traffic is understudied. Here we test the model that WAVE regulates Cadherin by polarizing its transport. In support of this model we show that: 1) endogenously tagged WAVE accumulates in vivo at several endocytic organelles, including recycling endosomes and at the Golgi; 2) likewise, Cadherin protein accumulates at recycling endosomes and Golgi; 3) loss of WAVE components reduces Cadherin accumulation at apically directed RAB-11-positive recycling endosomes and increases accumulation at Golgi. In addition, live imaging illustrates that dynamics and velocity of recycling endosomes enriched for RAB-11::GFP and RFP::RME-1 are reduced in animals depleted of WAVE components, and RAB-11::GFP movements are misdirected, suggesting WAVE powers and directs their movements. This in vivo study demonstrates the importance of WAVE in promoting polarized transport in epithelia, and supports a model that WAVE promotes cell-cell adhesion and polarity by promoting Cadherin transport. [Media: see text] [Media: see text] [Media: see text].

An Extremely Rare Variant of Pancreatic Ductal Adenocarcinoma Masquerading as Chronic Pancreatitis

Introduction/Objective

Primary Pancreatic signet-ring cell carcinoma (PPSRCC) is an extremely rare histologic variant with sparse literature. Herein, we describe a case of PPSRCC in a 75-year-old female with positive family history of pancreatic cancer (47y/o brother). The diagnosis was delayed secondary to diagnostic challenges on initial fine-needle aspiration (FNA).

Methods/Case Report

Diagnosing PPSRCC on FNA can be extremely difficult. Primary, and metastatic neoplasms to the pancreas may exhibit cytomorphological similarities to signet-ring cells, posing diagnostic challenges. Further, sampling of abundant background inflammatory cells during a biopsy can result in incorrect diagnosis of pancreatitis. Given the strong clinical suspicion based on imaging findings, a second FNA was performed which showed few atypical cells suspicious for carcinoma. Subsequently, the patient underwent neoadjuvant chemotherapy and Whipple resection. The tumor morphology is characterized by infiltrating cells with large mucin vacuoles and peripheric nucleus comprising > 50% of the mass lesion with perineural invasion, in a background of chronic inflammation and pancreatic intraepithelial neoplasia, grade III. A diagnosis of PPSRCC was rendered. Notably, lymph nodes (LN) showed no evidence of metastasis.

Results (if a Case Study enter NA)

NA.

Conclusion

Based on limited literature, PPSRCC is considered an aggressive malignancy with low survival rate, because of a high rate of metastasis. However, our case was rather unique given the lack of LN metastasis and the neodjuvant treatment strategy. As of February 2022, <10 cases have been reported with ill-defined characteristics and treatment guidelines.

Is the Primary Tumor Site of Ampullary Carcinoma Distinct in the Setting of Morphology Subtype?

Introduction/Objective

Ampullary cancer (AC) are rare and represents only 6% of the malignant periampullary tumors. Two main histologic subtypes of AC are pancreatobiliary (Pb-AC), and intestinal (In-AC). The data on the influencing role of several characteristics associated with AC subtypes on long term outcome is still emerging. Our study aimed to analyze the two subtypes Pb-AC and In-AC regarding their primary tumor site, median overall survival, and associated precursor lesion.

Methods/Case Report

Using the cBioPortal platform and systematic bioinformatical analysis of the Cancer Genome Atlas Baylor College of Medicine Cell Reports, 2016, 133 AC patients were included and analyzed based on their morphology subtype. Of which 62 patients had the intestinal subtype, and 71 had the pancreaticobiliary morphological subtype.

Results (if a Case Study enter NA)

The role of primary tumor site was statistically significant (p-value = 0.01) among subtypes Pb-AC and In-AC (See Figure). Remarkably, the primary tumor site most associated with the pancreaticobiliary subtype was the distal bile duct, and the intestinal subtype was intra-ampullary. Additionally, the precursor lesion identification (absent vs present) was statistically significant among the subtypes (p-value = 0.01). Further, the median overall survival in ampullary carcinoma varied among the morphology of the two subtypes: In-AC (75.56 months, (95% CI: 57.04-NA)) and Pb-AC (27.04 months, (95% CI: 18.29-NA)).

Conclusion

The findings in this study highlight the complex multifactorial role of the two morphological subtypes in AC. Further studies are essential for understanding the underlying tumor site specific molecular signatures leading to subtyping and their impact on prognosis.

PROBER identifies proteins associated with programmable sequence-specific DNA in living cells

DNA-protein interactions mediate physiologic gene regulation and may be altered by DNA variants linked to polygenic disease. To enhance the speed and signal-to-noise ratio (SNR) in the identification and quantification of proteins associated with specific DNA sequences in living cells, we developed proximal biotinylation by episomal recruitment (PROBER). PROBER uses high-copy episomes to amplify SNR, and proximity proteomics (BioID) to identify the transcription factors and additional gene regulators associated with short DNA sequences of interest. PROBER quantified both constitutive and inducible association of transcription factors and corresponding chromatin regulators to target DNA sequences and binding quantitative trait loci due to single-nucleotide variants. PROBER identified alterations in regulator associations due to cancer hotspot mutations in the hTERT promoter, indicating that these mutations increase promoter association with specific gene activators. PROBER provides an approach to rapidly identify proteins associated with specific DNA sequences and their variants in living cells.

P-128 Role of PGT-A and ERA to optimise reproductive outcomes of couples with recurrent implantation failure

Study question

In couples with Recurrent Implantation Failure (RIF), can Pre-implantation Genetic Testing for Aneuploidy (PGT-A) or Endometrial Receptive Array (ERA) help to optimise the reproductive outcomes?

Summary answer

In RIF patients PGT-A or ERA individually do not seem to optimize outcomes. PGT-A in-combination with ERA seems to be a beneficial intervention.

What is known already

Role of PGT-A and ERA to optimize reproductive outcomes has been ambigious. In this current study we wanted to evaluate their efficacy in RIF patients.

Study design, size, duration

This is a retrospective data of couples undergone treatment for RIF at our private fertility centre from January 2014 to July 2019. The study population was divided to four groups based on the treatments offered:

Group A: ERA (n = 47)

Group B: PGT-A (n = 54)

Group C: ERA+PGT-A (n = 49)

Group D: No PGT-A/ No ERA (n = 189)

Participants/materials, setting, methods

Couples with minimum two failed transfers were recruited. ICSI was the method of insemination. Blastocysts were subjected to genetic testing through Next-Generation Sequencing(NGS). All embryo transfers performed in a Frozen Embryo Replacement Cycle(FET). ERA was done as per our institutes Standard Operating Procedures(SOP) and for ERA patients ET was done as per the receptivity status.

Elective Single Euploid Blastocyst transfer (eSET) was done in grpB&C

un-screened double Blastocyst Transfer (DET) was done in grpA&D.

Main results and the role of chance

Clinical Pregnancy Rate (CPR), Miscarriage Rate (MR) Implantation Rate (IR), Multiple Pregnanacy rates (MPR) and Live Birth Rate (LBR) was evaluated in all groups.

Outcomes of groups A, B, C & D were as follows:

CPR – 68.09% Vs 62% Vs 68.42% Vs 70%

IR – 48.89% Vs 47.50% Vs 65.22% Vs 45%

MR – 12.77% Vs 9.25% Vs 5.26% Vs 17.89%

MPR – 16% Vs 0% Vs 0% Vs 17%

LBR – 51.06% Vs 46.8% Vs 63.16% Vs 45%

CPR was comaparble between all groups

ERA & PGT-A group seems to have the best IR, LBR with least miscarriage rates.

For RIF patients role of PGT or ERA when offered individually, doesn’t seem to optimize outcomes.

PGT-A in-combination with ERA seems to be beneficial to optimize outcomes.

Limitations, reasons for caution

This data is retrospective and there is a need for a well designed RCT to further validate the conclusion of this study. Caution needs to be exercised while offering PGT and ERA as they incurr additional financial burden to the patients.

Wider implications of the findings

Embryo Transfer cycles with a personalised window of implantation and transfer of a single Euploid embryo can help RIF patinets to have the best reproductive outcomes and can also help shorten the time to pregnancy.

Trial registration number

Not applicable

POS1224 RHEUMATOID ARTHRITIS DISEASE ACTIVITY ASSESSED BY PATIENT-REPORTED OUTCOMES AND FLOW CYTOMETRY BEFORE AND AFTER AN ADDITIONAL DOSE OF COVID-19 VACCINE

Background

The Centers for Disease Control and Prevention recommends an additional dose (AddDose) of COVID-19 vaccine for moderately/severely immunosuppressed individuals following an initial vaccine series. The American College of Rheumatology suggests that patients interrupt use (hold) certain DMARDs around the time of COVID-19 vaccination to improve immunogenicity. Whether holding DMARDs around an AddDose of COVID-19 vaccine affects RA disease activity or affects frequencies of lymphocyte populations that may be associated with RA disease activity remains unknown.

Objectives

To test whether RA disease activity and frequencies of lymphocyte populations change pre- vs. post-AddDose of COVID-19 vaccine, overall and stratified by holding vs. continuation of DMARDs around the AddDose.

Methods

Prospective observational cohort study of patients with RA who had completed an initial COVID-19 vaccine series (2 doses of mRNA vaccine or 1 dose of adenovirus vector vaccine). Subjects enrolled July-November 2021, prior to receiving an AddDose. Subjects held or continued DMARDs around the AddDose based on discussion with their rheumatologist and/or personal decision-making. RA disease activity was assessed weekly using the validated patient-reported RA Disease Activity Index-5 (RADAI-5) from enrollment through 4 weeks post-AddDose. We compared mean RADAI-5 pre- vs. post-AddDose using generalized estimating equations to account for correlated data among individual subjects. We aimed to enroll 60 subjects to achieve 91% power to detect a 15% non-inferiority margin in mean RADAI-5 post- vs. pre-AddDose. A subset of subjects with seropositive RA provided blood for flow cytometry at enrollment and week 4 post-AddDose. Frequencies of lymphocyte populations (T peripheral helper [Tph] cells, T follicular helper [Tfh] cells, age-associated B cells [ABC], and plasmablasts) were compared pre- vs. post-AddDose using Wilcoxon paired tests with Bonferroni correction.

Results

Among 71 subjects, mean age was 62 (SD 12) years, 85% were female, and 87% had seropositive RA. Methotrexate (42%) and TNF inhibitors (38%) were the most common DMARDs; 21% were taking prednisone. One subject reported COVID-19 infection prior to the AddDose. The mean RADAI-5 was 3.20 (SD 0.23) pre-AddDose compared to 3.25 (SD 0.23) after (difference of 1.6%, p=0.51). Figure 1 displays mean RADAI-5 in 35 (49%) subjects that held at least 1 DMARD and 36 (51%) subjects that continued all DMARDs around the AddDose. Mean change in RADAI-5 between pre- vs. post-AddDose did not significantly differ based on whether subjects held vs. continued DMARDs (p for interaction = 0.16). Frequencies of Tph, Tfh, ABC, and plasmablast populations did not significantly differ between the pre- and post-AddDose timepoints in subjects that held at least 1 DMARD (n=16) or subjects that continued all DMARD (n=11) (Figure 1).

Conclusion

RA disease activity, measured weekly with a validated patient-reported outcome, is stable around the time of an AddDose of COVID-19 vaccine. Lymphocyte subsets of interest in RA were also similar before and after the AddDose, supporting the observation of stable patient-reported RA disease activity. Holding DMARDs was not associated with greater RA disease activity following the AddDose.

Disclosure of Interests

Sara Tedeschi Consultant of: NGM Biopharmaceuticals: payment to Dr. Tedeschi, Grant/research support from: Moderna: research support to institution, Jacklyn Stratton: None declared, Jack Ellrodt: None declared, Mary Grace Whelan: None declared, Keigo Hayashi: None declared, Kazuki Yoshida Consultant of: OM1, Inc: consulting fees paid to Dr. Yoshida, Lin Chen: None declared, Ifeoluwakiisi Adejoorin: None declared, Kathryne E. Marks: None declared, A. Helena Jonsson Grant/research support from: Moderna: research support to institution

Amgen: payment to institution for unrelated project, Deepak Rao Speakers bureau: Merck: honoraria lecture paid to Dr. Rao, Consultant of: Janssen: consulting fees paid to Dr. Rao

Bristol Myers Squibb: participation on scientific advisory board with compensation paid to Dr. Rao, Grant/research support from: Moderna: research funding paid to institution

Janssen: research funding paid to institution

Merck: research funding paid to institution, Daniel Solomon Grant/research support from: Moderna: payment made to institution

Amgen: payment to institution

Abbvie: payment to institution

CorEvitas: payment to institution

POS0402 CLONALLY EXPANDED CD38hi CYTOTOXIC CD8 T CELLS DEFINE THE T CELL INFILTRATE IN CHECKPOINT INHIBITOR-ASSOCIATED ARTHRITIS

Background

Immune checkpoint inhibitor (ICI) therapies that promote T cell activation have improved outcomes for advanced malignancies yet can also elicit harmful autoimmune reactions. The T cell mechanisms mediating these iatrogenic autoimmune events remain unclear.

Objectives

To investigate the immunophenotype, transcriptomic feature and clonotypes of T cells from joints of patients affected by ICI-induced inflammatory arthritis (ICI-arthritis).

Methods

Detailed immunophenotyping was performed on mononuclear cells from synovial fluid (SF) using mass cytometry and flow cytometry to identify significantly altered populations in ICI-A compared to seropositive rhrumatoid arthritis (RA) and psoriatic arthritis (PsA) (p<0.05). Bulk RNA-seq was performed on altered SF CD8 T cell subsets from ICI-A, RA and PsA to investigate their transcriptomic features. Cytokine profile and pathways enriched in ICI-A CD8 T cells were examined using differentially expressed genes, intracellular staining, and in vitro culture. TCR clonotypes were examined using single cell RNA-seq of T cells from synovial fluid, tissue and blood of ICI-A.

Results

Compared to the autoimmune arthritides RA and PsA, ICI-arthritis joints contained an expanded CD38hi CD127- CD8+ T cell subset that displays cytotoxic, effector, and interferon (IFN) response signatures. Exposure of synovial T cells to Type I IFN, more so than IFN-γ, induced the CD38hi cytotoxic phenotype. Single cell transcriptomic and T cell repertoire (TCR) analyses indicated that the abundance of CD38hi CD8 T cells in ICI-arthritis resulted from proliferation of a limited number of clones. The CD38hi population appeared distinct from dysfunctional T cells and clonally most related to TCF7+ memory populations. Comparison of synovial tissue from bilateral knees of the same patient demonstrated considerable sharing of TCR clonotypes among CD38hi CD8 T cells between the two joints. Further, TCR clonotypes expanded in synovial fluid of ICI-arthritis patients were detected in circulating T cells, and circulating CD38hi CD8 T cells are also expanded in ICI-arthritis patients.

Conclusion

These results define a distinct CD8 T cell subset in the synovial fluid and in the circulation of patients with ICI-A that may be directly activated by ICI therapy to mediate a tissue-specific autoimmune response.

Disclosure of Interests

None declared.

Global survey-based assessment of lifestyle changes during the COVID-19 pandemic

Along with the major impact on public health, the COVID-19 outbreak has caused unprecedented concerns ranging from sudden loss of employment to mental stress and anxiety. We implemented a survey-based data collection platform to characterize how the COVID-19 pandemic has affected the socio-economic, physical and mental health conditions of individuals. We focused on three broad areas, namely, changes in social interaction during home confinement, economic impact and their health status. We identified a substantial increase in virtual interaction among individuals, which might be a way to alleviate the sudden unprecedented mental health burden, exacerbated by general awareness about viral infections or other manifestations associated with them. The majority of participants (85%) lived with one or more companions and unemployment issues did not affect 91% of the total survey takers, which was one of the crucial consequences of the pandemic. Nevertheless, measures such as an increased frequency of technology-aided distant social interaction, focus on physical fitness and leisure activities were adopted as coping mechanisms during this period of home isolation. Collectively, these metrics provide a succinct and informative summary of the socio-economic and health impact of the COVID-19 pandemic on the individuals. Findings from our study reflect that continuous surveillance of the psychological consequences for outbreaks should become routine as part of preparedness efforts worldwide. Given the limitations of analyzing the large number of variables, we have made the raw data publicly available on the OMF ME/CFS Data Center server to facilitate further analyses (https://igenomed.stanford.edu/dataset/survey-study-on-lifestyle-changes-during-covid-19-pandemic).

Granular Cell Tumor Confined To The Muscularis Propria Of The Appendix: A Case Report

Introduction/Objective

Granular cell tumors (GCTs) are exceedingly rare soft tissue tumors that are usually benign and are thought to arise from Schwann cell origin. GCTs most commonly occur in the skin, subcutaneous tissue, and oral cavity. However, they can involve any organ, including the gastrointestinal (GI) tract, of which esophagus is most common, followed by large intestine. We report a case of a 58 year old female who presented with acute

appendicitis, followed by an appendectomy to reveal an incidental GCT.

Methods

This report is a retrospective study of an appendiceal GCT in which we reviewed the case and the histology. In addition, a brief literature review of gastrointestinal GCTs was performed to further elucidate the incidence, location, histopathology, and differential diagnoses for this lesion.

Results

Histological analysis of the tumor nodule reveals nests of epithelioid cells with abundant granular eosinophilic cytoplasm. The nuclei are bland, small, and round to oval, with rare spindled morphology.

Immunohistochemistry for S-100 protein shows diffuse strong cytoplasmic and nuclear positivity, which is suggestive of Schwann cell origin. In the GI tract, GCTs are routinely confined to the mucosa, submucosa, or both; however the tumor nodule in our case is contained within the muscularis propria.

Conclusion

It is estimated that 5–11% of GCTs occur in the gastrointestinal tract, while only 13 GCT cases of the appendix have been reported. In addition to the previously stated rarity, is the limited involvement of the muscularis propria, with which GCTs typically are not associated. To our knowledge, this is the first confirmed GCT of the appendix that solely involves the muscularis propria, in English medical literature.

Hepatoblastoma With Rubinstein-Taybi Syndrome: A Rare Association

Introduction/Objective

Hepatoblastoma is a malignant neoplasm of liver, exclusively seen in pediatric population. It has been known to occur with various syndromes like Li-fraumeni, Beckwith-Wiedemann, and Simpson-Golabi- Behmel among others. Small undifferentiated cells and macro-trabecular pattern with increased mitotic activity and AFP&gt;100 are associated with unfavorable prognosis. Rubinstein-Taybi syndrome is a rare genetic disease. Even though there has been intensive research on the genetic and epigenetic function of the CREBBP and EP300 genes in animal models, the etiology of this rare and devastating syndrome is largely unknown. Hepatoblastoma with Rubinstein-Taybi syndrome is an extremely rare occurrence.

Methods

Here we present an incidental case of Hepatoblastoma with Rubinstein-Taybi syndrome

Results

A 17-month-old Caucasian female with Rubinstein-Taybi syndrome, was found to have an incidental 1.1 cm nodule in the right lobe of liver. Her AFP was elevated (244.9ng/ml). Hepatic resection revealed a well-circumscribed tan white mass, measuring 3.5 cm in the greatest dimension. On microscopy, uniform round to cuboidal cells resembling fetal hepatocytes, with finely granular cytoplasm, small round nuclei, and indistinct nucleoli were seen. The cells were arranged in solid sheets and scant trabecular arrangement separated by narrow sinusoids. The tumor displayed predominantly fetal histology, with rare embryonal and small undifferentiated cell nests. The diagnosis of Hepatoblastoma was made. The patient underwent chemotherapy and was doing well at 5-years follow-up.

Conclusion

Extensive screening of patients in recent times has revealed mutations in CREBBP and EP300 in only around 50% of cases. The genetic and epigenetic associations of the syndrome in the remaining half of cases remains to be identified. Hepatoblastoma with Rubinstein-Taybi Syndrome is an extremely rare occurrence and might shed some light on other genes that could be involved in this syndrome. Further studies to review the mutation spectrum to understand the causative molecular mechanisms are deemed essential.

Squamous Cell Carcinoma Of Pancreas: An Exceedingly Rare Entity In A Young Female

Introduction/Objective

Squamous cell carcinoma(SqCC) of Pancreas is a vanishingly rare neoplasm with dismal survival. Only a handful of cases are ever reported as pure SqCC reportedly accounts for &lt;1% of malignancies of exocrine pancreas. Although, few theories have been proposed in an attempt to explain origin of this tumor including the possibility of (1)common progenitor cell and (2)squamous metaplasia, none have been proven with concrete evidence.

Methods

Here, we are presenting a case of squamous cell carcinoma of pancreas in a 33-year-old female who presented with 2-year history of right upper quadrant abdominal pain and a palpable mass. The imaging showed a multi-lobulated cystic mass encasing cystic duct, portal vein, and superior mesenteric artery.

Results

Grossly the mass was 5.2 cm in the greatest dimension. The mass revealed solid and cystic areas and was filled with hemorrhagic debris. On microscopy, the cyst wall was infiltrated by malignant neoplasm composed of irregular tongues and cords of malignant cells with nests of central keratinization. The tumor was consistent with squamous cell carcinoma. Foci of high grade cells with oval to spindled hyperchromatic nuclei, with many prominent nucleoli were also noted. There was no evidence of glandular component despite adequate sampling. The differential diagnoses of pancreatoblastoma and metastatic squamous cell carcinoma were considered and excluded.

Conclusion

SqCC of Pancreas is an exceedingly rare neoplasm of Pancreas. The diagnosis is made after extensive work up, adequate sampling and ruling out other common primary tumors and the possibility of metastasis. It usually follows an aggressive course with resistance to conventional neoadjuvant therapy. During the recent years, survival rates have shown some improvement with respectability and low to intermediate grade emerging as favorable prognostic factors. However, to further validate such findings noted in published case reports of this rare entity, collaborative studies with pooled data are deemed necessary.

Hirschsprung’s Disease: Two Cases of Total Intestinal Aganglionosis

Introduction/Objective

Hirschsprung’s disease is a disorder associated with an absence of ganglion cells in a segment of the bowel. Total colonic and small bowel aganglionosis occurs in less than 1% of all Hirschsprung’s disease patients. Even rarer is the finding of Haddad syndrome, the coexistence of congenital central hypoventilation syndrome and Hirschsprung’s disease. Congenital central hypoventilation syndrome has approximately 1,000 reported cases, with colonic aganglionosis being associated with 15-20% of those cases. The prevalence of Hirschsprung’s disease with congenital renal anomalies may be another underreported finding.

Methods

Here, we report two rare cases of Hirschsprung’s disease with significant extension in the small bowel. One case involves a 38-week gestational age male infant admitted for apnea and another case involves 39-week gestational age female infant admitted for vomiting.

Results

Both infants had rectal suction biopsies confirming the absence of ganglion cells. The male infant had mapping biopsies which histologically showed hypertrophic nerve fibers and an absence of ganglion cells in the colon extending up to 70 cm proximal to the ileocecal valve. Calretinin immunostaining confirmed aganglionsis. Genetic testing showed a PHOX2B gene mutation carrying 32 polyalanine repeat mutations, confirming a diagnosis of congenital central hypoventilation syndrome coexisting with Hirschsprung’s disease. The female infant had intraoperative frozen sections that identified ganglion cells throughout the colon. On permanent sections, there was an absence of ganglion cells in the upper rectum extending up to 65 cm proximal to the ileocecal valve. She also was noted to have agenesis of the left kidney and a urachal remnant. Genetic testing was negative for RET mutations.

Conclusion

Overall, these cases provide further information on a rare variant of Hirschsprung’s disease that includes significant portions of the small bowel. Additionally, this study adds to the documented reports of Haddad syndrome and the connections between renal anomalies with Hirschsprung’s disease. Last, this series alludes to the difficulties of frozen section diagnosis of this disease.

A Rare Case Of Solid Pseudopapillary Neoplasm (Spn) Of Pancreas In A Male Patient

Introduction/Objective

SPN is a rare neoplasm of the pancreas with low malignant potential and unknown histologic origin. It has a strong preponderance in young females (Female:Male ratio = 9:1).

Methods

We present a case of a 32-year-old morbidly obese male, who presented at our institution with an incidental large heterogeneous mass in the distal pancreas on imaging. Distal pancreatectomy with splenectomy was performed.

Results

Grossly, the mass measured 8 centimeters in greatest dimension with a tan-brown variegated cut surface.

The microscopic sections revealed a well-encapsulated tumor comprised of solid and cystic components. The solid areas show sheets and nests of hyalinized vascular stroma surrounded by small uniform cells with eosinophilic cytoplasm and bland round-to-ovoid nuclei. The immunohistochemical (IHC) stains showed variable positive expression with CD10, beta-catenin, and progesterone receptors. We also stained for newer putative IHC markers including LEF-1, TFE-3, SOX-11, and AMACR. Among them, LEF-1 was the only marker that showed 100% strong and diffuse, nuclear positive expression while the other three showed variable positive expression. These novel results are noted for the first time and is in congruence with the emerging molecular diagnostic finding that LEF-1 expresses the β-catenin binding domain of Wnt/β-catenin signaling pathway involved in the histologic origin of this tumor.

Conclusion

We present a rare case of SPN in a male patient. Additionally, this is the first case to report the staining pattern of newer putative markers of LEF-1, TFE-3, SOX-11, and AMACR that may suggest the pathobiology of histologic origin of this tumor.

Clinico-pathologic Features of Esophageal Poorly Differentiated Neuroendocrine Carcinomas, a Case Series and Review of Literature

Introduction/Objective

Esophageal neuroendocrine carcinomas (NECs) constitute an extremely rare and distinct group of neoplasms. The clinico-pathologic characteristics are poorly understood and differ starkly from high grade well differentiated neuroendocrine tumors. Only one case series describing clinico-pathologic features of NECs has been described in recent literature.

Methods

We describe a case series of three patients highlighting the typical presentation, diagnostic techniques and pathologic attributes for this rare disease process.

Results

All three patients were middle age to elderly with two males (ages 58 and 83) and one female (age 72). The typical presentation was dysphagia (2/3, 66%) followed by severe GERD (1/3, 33%). Typical locations were distal esophagus (2/3, 66%) and gastro-esophageal junction (1/3, 33%). Computed tomography showed bulky masses in all patients (3/3, 100%) with median size of 5.6 cm. PET imaging showed metastatic disease (mediastinal or epigastric lymphadenopathy and lung metastasis) in 2/3, 66% of the patients. All the patients were found to have necrotic masses on EGD with biopsy showing poorly differentiated neuroendocrine carcinoma in all (3/3, 100%). Immuno- histochemical stains revealed Synaptophysin positivity in 3/3, 100%, Chromogranin in 1/3, 33% and CD56 in 1/3, 33% of the patients. Patients with metastatic disease at presentation (2/3, 66%) opted for palliative care while the patient without any evidence of metastasis (1/3, 33%) underwent surgical resection followed by chemotherapy.

Conclusion

ENCs are an exceedingly rare group of malignant neoplasm with variable presentations posing a diagnostic challenge for the clinician and pathologist alike. Most patients tend to be elderly with advanced disease at presentation and guarded prognosis. This case series underscores the importance of including this entity among the differential diagnosis for poorly differentiated carcinomas of the distal esophagus. IHC with positive neuroendocrine markers particularly Synaptophysin helps make the correct diagnosis when combined with typical morphology.

OP0328 A UNIQUE PD1+CD38+ CD8+ T CELL POPULATION CHARACTERIZES CHECKPOINT INHIBITOR-ASSOCIATED INFLAMMATORY ARTHRITIS

Background:

Immune checkpoint inhibitors (CI) are monoclonal antibodies that block CTLA-4, PD-1 or PD-L1, resulting in cytotoxic T cell activation in the tumor microenvironment. They have revolutionized the management of metastatic cancer but unleash “immune related adverse events” in > 80% of treated patients, including inflammatory arthritis in ~4%1. CI-associated arthritis (CI-A) often presents as a symmetrical polyarthritis, phenotypically indistinguishable from rheumatoid arthritis (RA), but whether it shares cellular and molecular features of RA has not been determined.

Objectives:

To compare synovial fluid (SF) T cell populations from CI-A patients to those in patients with RA, phenotypically and functionally.

Methods:

We immunophenotyped SF mononuclear cells from patients with CI-A caused by anti-PD-(L)1 therapy (n=9), seropositive RA (n=5), and psoriatic arthritis (PsA) (n=5) using a 39-marker mass cytometry (CyTOF) panel. FlowSOM was used to cluster CD4 and CD8 T cells into 15 ‘metaclusters’ based on multidimensional phenotypes. We used Kruskal-Wallis or Mann-Whitney tests to identify significantly altered populations (p<0.05), which we confirmed by biaxial gating. Flow cytometry was used to confirm SF findings in an independent cohort, and to identify cells of interest in peripheral blood. Cytokine staining was performed on sorted T cells populations after CDCD3/CD28 stimulation for 72 hours, followed by 4 hour PMA/ION+BRA/MON restimulation.

Results:

In CI-A patients, T cells represented 50% of SF mononuclear cells (53% CD4, 40% CD8), followed by monocytes (24%) and NK cells (8%), comparable to RA and PsA. However, FlowSOM analysis revealed expansion of a distinct population of PD-1+CD38hiCD127-CD8 T cells (CD8 metacluster2) (Fig. 1). These cells comprised 30% of CD8+ SF T cells in CI-A, a 3.4-fold increase over RA/PsA, p=0.0002 (Fig. 2). Over 40% of these cells expressed Ki67 in CI-A, suggesting active proliferation. Flow cytometry on SF cells from an independent cohort of CI-A patients (n= 5) and RA/PsA comparators (n= 9) confirmed our findings. PD-1+CD38hiCD127-CD8 T cells were also expanded in the blood of CI-A patients, where they represented 4.6% of CD8 Tcells, a 2.8-fold increase over RA, p = 0.0057. In addition to expressing high levels of PD-1, CD38hiCD127-, these CD8 T cells express other immune checkpoint receptors including ICOS and TIGIT. After in vitro stimulation, CD38hiCD127-CD8 T cells produced granzyme B along with TNF and IFN-γ at comparable levels to other CD8 populations, suggesting that they are not functionally exhausted.

Figure 1.

Mass cytometry CD8+T cells (tSNE plots) with FlowSOM metaclusters.

Figure 2.

Synovial fluid PD-1+CD38hiCD127-CD8+T cells

FlowSOM analysis of SF CD4 T cells in CI-A patients revealed the expansion of a subpopulation of CD4 cells with a similar surface phenotype of PD-1+CD38hiCD127-(metacluster2, 10% of CD4s in CI-A, a 2.4-fold increase over RA/PsA, p=0.0047). In contrast, RA patients had a significantly expanded population of PD-1hiICOS+ CD4 T peripheral helper (Tph) cells (metacluster5, 30% of CD4s in RA, p=0.006), but these cells were not expanded in CI-A (Fig 3).

Figure 3.

Synovial fluid CD4+T peripheral helper cells

Conclusion:

CyTOF analysis of SF revealed a uniquely expanded PD-1+CD38hiCD127-CD8 T cell population in CI-A not present in RA or PsA, and a similar PD-1+CD38hiCD127-CD4 T cell population. These cells may contribute to the amplified immune response seen in CI-A patients. Further functional and transcriptional analysis of these cells will help to elucidate their function may reveal key mechanisms driving CI-associated immune related adverse events.

References:

[1]Kostine M. Ann Rheum Dis 2018;77(3):393-398

Disclosure of Interests:

Runci Wang: None declared, Karmela Kim Chan: None declared, Amy Cunningham-Bussel: None declared, Laura Donlin Consultant of: Consultant – Genentech/Roche, Gregory Vitone: None declared, Aidan Tirpack: None declared, Caroline Benson: None declared, Gregory Keras: None declared, A. Helena Jonsson: None declared, Michael Brenner: None declared, Anne Bass: None declared, Deepak Rao Grant/research support from: Has received research grant support from Celgene and Merck., Consultant of: Has received consulting fees or honoraria from Merck, Pfizer, GlaxoSmithKine, Bristol-Myers Squibb, Janssen, and Scipher Medicine

Muscle-derived Dpp regulates feeding initiation via endocrine modulation of brain dopamine biosynthesis

In this study, Robles-Murguia et al. set out to examine whether muscle-secreted hormones regulate feeding. Using Drosophila as a model system combined with several in vivo and in vitro experiments, the authors identify Decapentaplegic (Dpp) as a myokine that can signal from the muscle to the brain to control feeding by altering dopamine synthesis through transcriptional regulation of tyrosine hydroxylase (TH).

In animals, the brain regulates feeding behavior in response to local energy demands of peripheral tissues, which secrete orexigenic and anorexigenic hormones. Although skeletal muscle is a key peripheral tissue, it remains unknown whether muscle-secreted hormones regulate feeding. In Drosophila, we found that decapentaplegic (dpp), the homolog of human bone morphogenetic proteins BMP2 and BMP4, is a muscle-secreted factor (a myokine) that is induced by nutrient sensing and that circulates and signals to the brain. Muscle-restricted dpp RNAi promotes foraging and feeding initiation, whereas dpp overexpression reduces it. This regulation of feeding by muscle-derived Dpp stems from modulation of brain tyrosine hydroxylase (TH) expression and dopamine biosynthesis. Consistently, Dpp receptor signaling in dopaminergic neurons regulates TH expression and feeding initiation via the downstream transcriptional repressor Schnurri. Moreover, pharmacologic modulation of TH activity rescues the changes in feeding initiation due to modulation of dpp expression in muscle. These findings indicate that muscle-to-brain endocrine signaling mediated by the myokine Dpp regulates feeding behavior.

Circadian gene variants and the skeletal muscle circadian clock contribute to the evolutionary divergence in longevity across Drosophila populations

Organisms use endogenous clocks to adapt to the rhythmicity of the environment and to synchronize social activities. Although the circadian cycle is implicated in aging, it is unknown whether natural variation in its function contributes to differences in lifespan between populations and whether the circadian clock of specific tissues is key for longevity. We have sequenced the genomes of Drosophila melanogaster strains with exceptional longevity that were obtained via multiple rounds of selection from a parental strain. Comparison of genomic, transcriptomic, and proteomic data revealed that changes in gene expression due to intergenic polymorphisms are associated with longevity and preservation of skeletal muscle function with aging in these strains. Analysis of transcription factors differentially modulated in long-lived versus parental strains indicates a possible role of circadian clock core components. Specifically, there is higher period and timeless and lower cycle expression in the muscle of strains with delayed aging compared to the parental strain. These changes in the levels of circadian clock transcription factors lead to changes in the muscle circadian transcriptome, which includes genes involved in metabolism, proteolysis, and xenobiotic detoxification. Moreover, a skeletal muscle-specific increase in timeless expression extends lifespan and recapitulates some of the transcriptional and circadian changes that differentiate the long-lived from the parental strains. Altogether, these findings indicate that the muscle circadian clock is important for longevity and that circadian gene variants contribute to the evolutionary divergence in longevity across populations.

Fibrin Affinity and Clearance of t-PA Deletion and Substitution Analogues

To investigate structure-function relationships in tissue-type plasminogen activator (t-PA) we deleted the following domains in the heavy chain: a) The epidermal growth factor domain (t-PA del. G), b) the finger domain, and the epidermal growth factor domain (t-PA del. FG), and c) the finger, the epidermal growth factor and Kr-ingle 1 (1-PA del, FGK1). To study specificly the function of the growth factor domain we made two substitutions of d) 8 amino acids (consensus sequence) in the growth factor domain (t-PA G-CS) and c) the whole domain with factor IX growth factui doniuin (t-PA G-IX). Finally, f) an analogue with substitution in the finger domain (fibronectin consensus sequence) was constructed (t-PA F-CS).

A reduced fibrin binding of all the analogues was found. The fibrin stimulated activity of all analogues was also reduced and correlated to the fibrin binding. In contrast, the activity of the analogues in the clot lysis assay and the plate assay were only slightly reduced as compared to authentic t-PA. This suggested that at high fibrin concentrations the decreased fibrin affinity was less ciitical for obtaining a high fibrinolytic activity.

All analogues had a prolonged half-life in vivo as compared to authentic t-PA. The assumption of clearance mechanism involving mainly the growth factor region (or Kringlc 1) was not challenged by the observation of a prolonged half-life for the substitution analogue t-PA F-CS.

Our results indicate that a high affinity for fibrin and rapid elimination in vivo of t-PA require a nearly intact conformation of the N-terminal part of the molecule.

Context-dependent crypsis: a prey's perspective of a color polymorphic predator

Many animals use body coloration as a strategy to communicate with conspecifics, prey, and predators. Color is a trade-off for some species, since they should be visible to conspecifics but cryptic to predators and prey. Some flower-dwelling predators, such as crab spiders, are capable of choosing the color of flowers where they ambush flower visitors and pollinators. In order to avoid being captured, visitors evaluate flowers visually before landing. The crab spider Mecaphesa dubia is a polymorphic species (white/purple color morphs), which inhabits the flower heads of a dune plant, Palafoxia lindenii. Using full-spectrum photography of spiders and flowers, we evaluated how honeybees perceived the spiders at different distances. Using visual modeling, we obtained the chromatic and achromatic contrasts of the spiders on flower heads as perceived by honeybees. Purple morphs were found mainly on the receptacle area and white morphs were equally likely to be found in the flowers and receptacle. According to theoretical modeling, white morphs were visible to honeybees from a distance of 10 cm in receptacle area but appeared to be cryptic in the flower area. Purple morphs were cryptic on the receptacle and less so when they were on the flowers. Spiders on flower heads are predicted to be more easily detected by honeybees using chromatic contrast. Our study shows that the conspicuousness of flower dwelling spiders to honeybees depends on the color morph, the distance of observation, and the position of spider on the flower head.

Peer Observation of Rounds Leads to Collegial Discussion of Teaching

PROBLEM

Faculty in the Division of Hospital Medicine provide most of the clinical teaching for learners at our institution. The majority of these faculty are Assistant Professors with limited formal instruction in clinical teaching. Previous Divisional strategies to improve clinical teaching ability included discussion of effective teaching behaviors, developing written expectations for teaching faculty, and instituting seminars on effective clinical teaching. Heretofore, the Division had not utilized a direct observation exercise.

INTERVENTION

We developed a direct observation exercise to encourage discussion of teaching techniques and contemplation of change. Using a social learning model, we developed a peer-to-peer observation followed by a nonevaluative discussion. We created a tool for describing teaching behaviors in 5 domains that were similar to or different from the usual behavior of the observing peer: learner presentations, team leadership, bedside teaching, professionalism, and other. After the observation, the observing and observed faculty met to discuss observed teaching behaviors. Both faculty members discussed and then recorded any teaching behaviors that they planned to adopt or change.

CONTEXT

We implemented this intervention in a 22-member Academic Division of Hospital Medicine at a tertiary care medical center in the United States. A high proportion were junior faculty and graduates of our residency program.

OUTCOME

We reviewed records of 28 of 31 observations that were completed during the initial 9-month period of implementation and later surveyed faculty. The exercise resulted in planned changes in teaching behaviors that included instituting new methods to improve teaching team leadership, triaging of patients seen on rounds, faculty behaviors during oral presentations, giving real-time feedback, use of technology and humor, demonstrating physical examination findings, and modeling professional behaviors. Faculty later reported adoption of new teaching behaviors that were important to them.

LESSONS LEARNED

This exercise was easily implemented, resulted in planned changes by both observed and observing peers, and resulted in widespread adoption of some specific teaching behaviors. The most commonly planned change dealt with team leadership or organizational issues. When given the freedom to choose, junior faculty were more likely to observe senior faculty.

A predator's response to a prey's deterrent signal changes with experience

Prey signalling to predators is an attempt to divert or nullify an attack even before it occurs. If these signals are backed up by a potent defence, then the likelihood of the predators learning to avoid them is high. In species that use deceptive signalling, predators could learn to overcome such a display and diminish the efficacy of the display. We studied the effect of experience on the efficacy of tephritid fly displays against jumping spiders. We compared attacks on displaying flies, non-displaying flies, and two other prey species (a facile prey and a prey with a defence). Spiders were more likely to attack displaying flies over time. However, spiders that were familiar with the fly appearance but not display also increased their attack rates. We suggest that spiders attend to both components of the fly display, i.e. motion and appearance, but with motion cues taking priority.

The impact of Cognitive Processing Therapy on stigma among survivors of sexual violence in eastern Democratic Republic of Congo: results from a cluster randomized controlled trial

Background

Sexual violence is associated with a multitude of poor physical, emotional, and social outcomes. Despite reports of stigma by sexual violence survivors, limited evidence exists on effective strategies to reduce stigma, particularly in conflict-affected settings. We sought to assess the effect of group Cognitive Processing Therapy (CPT) on stigma and the extent to which stigma might moderate the effectiveness of CPT in treating mental health problems among survivors of sexual violence in the Democratic Republic of Congo.

Methods

Data were drawn from 405 adult female survivors of sexual violence reporting mental distress and poor functioning in North and South Kivu. Women were recruited through organizations providing psychosocial support and then cluster randomized to group CPT or individual support. Women were assessed at baseline, the end of treatment, and again six months later. Assessors were masked to women’s treatment assignment. Linear mixed-effect regression models were used to estimate (1) the effect of CPT on feelings of perceived and internalized (felt) stigma, and (2) whether felt stigma and discrimination (enacted stigma) moderated the effects of CPT on combined depression and anxiety symptoms, posttraumatic stress, and functional impairment.

Results

Participants receiving CPT experienced moderate reductions in felt stigma relative to those in individual support (Cohen’s D = 0.44, p = value = 0.02) following the end of treatment, though this difference was no longer significant six-months later (Cohen’s D = 0.45, p = value = 0.12). Neither felt nor enacted stigma significantly moderated the effect of CPT on mental health symptoms or functional impairment.

Conclusions

Group cognitive-behavioral based therapies may be an effective stigma reduction tool for survivors of sexual violence. Experiences and perceptions of stigma did not hinder therapeutic effects of group psychotherapy on survivors’ mental health.

Trial registration

ClinicalTrials.gov NCT01385163.

Electronic supplementary material

The online version of this article (10.1186/s13031-018-0142-4) contains supplementary material, which is available to authorized users.

The INtegrating DEPrEssioN and Diabetes treatmENT (INDEPENDENT) study: Design and methods to address mental healthcare gaps in India

INTRODUCTION

Depression and diabetes are highly prevalent worldwide and often co-exist, worsening outcomes for each condition. Barriers to diagnosis and treatment are exacerbated in low and middle-income countries with limited health infrastructure and access to mental health treatment. The INtegrating DEPrEssioN and Diabetes treatmENT (INDEPENDENT) study tests the sustained effectiveness and cost-effectiveness of a multi-component care model for individuals with poorly-controlled diabetes and depression in diabetes clinics in India.

MATERIALS AND METHODS

Adults with diabetes, depressive symptoms (Patient Health Questionnaire-9 score≥10), and ≥1 poorly-controlled cardiometabolic indicator (either HbA1c≥8.0%, SBP≥140mmHg, and/or LDL≥130mg/dl) were enrolled and randomized to the intervention or usual care. The intervention combined collaborative care, decision-support, and population health management. The primary outcome is the between-arm difference in the proportion of participants achieving combined depression response (≥50% reduction in Symptom Checklist score from baseline) AND one or more of: ≥0.5% reduction in HbA1c, ≥5mmHg reduction in SBP, or ≥10mg/dl reduction in LDL-c at 24months (12-month intervention; 12-month observational follow-up). Other outcomes include control of individual parameters, patient-centered measures (i.e. treatment satisfaction), and cost-effectiveness.

RESULTS

The study trained seven care coordinators. Participant recruitment is complete - 940 adults were screened, with 483 eligible, and 404 randomized (196 to intervention; 208 to usual care). Randomization was balanced across clinic sites.

CONCLUSIONS

The INDEPENDENT model aims to increase access to mental health care and improve depression and cardiometabolic disease outcomes among complex patients with diabetes by leveraging the care provided in diabetes clinics in India (clinicaltrials.gov number: NCT02022111).

OPTIMUM: a protocol for a multicentre randomised controlled trial comparing Out Patient Talc slurry via Indwelling pleural catheter for Malignant pleural effusion vs Usual inpatient Management

INTRODUCTION

The development of malignant pleural effusion (MPE) results in disabling breathlessness, pain and reduced physical capability with treatment a palliative strategy. Ambulatory management of MPE has the potential to improve quality of life (QoL). The OPTIMUM trial is designed to determine whether full outpatient management of MPE with an indwelling pleural catheter (IPC) and pleurodesis improves QoL compared with traditional inpatient care with a chest drain and talc pleurodesis. OPTIMUM is currently open for any centres interested in collaborating in this study.

METHODS AND ANALYSIS

OPTIMUM is a multicentre non-blinded randomised controlled trial. Patients with a diagnosis of MPE will be identified and screened for eligibility. Consenting participants will be randomised 1:1 either to an outpatient ambulatory pathway using IPCs and talc pleurodesis or standard inpatient treatment with chest drain and talc pleurodesis as per British Thoracic Society guidelines. The primary outcome measure is global health-related QoL at 30 days measured using the EORTC QLQ-C30 questionnaire. Secondary outcome measures include breathlessness and pain measured using a 100 mm Visual Analogue Scale and health-related QoL at 60 and 90 days. A sample size of 142 patients is needed to demonstrate a clinically significant difference of 8 points in global health status at 30 days, for an 80% power and a 5% significance level.

ETHICS AND DISSEMINATION

The study has been approved by the NRES Committee South East Coast-Brighton and Sussex (reference 15/LO/1018). The trial results will be published in peer-reviewed journals and presented at scientific conferences.

TRIAL REGISTRATION NUMBERS

UKCRN19615 and ISRCTN15503522; Pre-results.

Antipredator behavior of the new mass-reared unisexual strain of the Mexican Fruit Fly

Tephritid pests controlled through the sterile insect technique (SIT) are mass-reared and subsequently released in affected areas. Several quality parameters are currently used to test adults, but none take into account interactions with a predator. When sterile males are released in the field, they will need to avoid predators until they reach sexual maturity and survive long enough to mate with wild females. Spiders are one of the most common predators that flies may encounter in release sites. In this study, we evaluated the antipredator behavior of a mass-reared sterile unisexual strain ('Tapachula-7') of the Mexican fruit fly Anastrepha ludens (Diptera: Tephritidae) against their spider predators. We sampled spiders in citrus trees to determine which families could be more common. We established the baseline activity rates of sterile Tapachula-7 (Tap-7) flies in comparison with wild flies. We also tested the behavior of the fertile and sterile bisexual strain and wild flies against hunting spiders (Family Salticidae) and orb building spiders (Family Tetragnathidae). We recorded 18 spider families, with Salticidae being the most dominant. Tap-7 flies diminished their activity in comparison with wild males at 1800 h but showed similar activity levels earlier in the day. When exposed to orb-web spiders (Leucauge venusta), Tap-7, fertile and sterile males from the bisexual strain had similar rates of survival, but Tap-7 males showed lower survival than wild males. Against hunting spiders (Phidippus audax), wild males had higher probability of defensive wing displays, but there was no difference in spider attack rates. In general, sterile Tap -7 males performed as well as males from the bisexual strain, although they had lower survival than wild males. This could be due to either mass-rearing and/or irradiation effects. We recommend the use of the defensive wing display behavior as a quality parameter and propose a rapid and effective method to evaluate fly activity. The efficiency of SIT will be improved if released sterile males have the same antipredator repertoire as their wild counterparts.

Operating experience feedback from safety significant events at research reactors

Operating experience feedback is an effective mechanism to provide lessons learned from the events and the associated corrective actions to prevent recurrence of events, resulting in improving safety in the nuclear installations. This paper analyzes the events of safety significance that have been occurred at research reactors and discusses the root causes and lessons learned from these events. Insights from literature on events at research reactors and feedback from events at nuclear power plants that are relevant to research reactors are also presented along with discussions. The results of the analysis showed the importance of communication of safety information and exchange of operating experience are vital to prevent reoccurrences of events. The analysis showed also the need for continued attention to human factors and training of operating personnel, and the need for establishing systematic ageing management programmes of reactor facilities, and programmes for safety management of handling of nuclear fuel, core components, and experimental devices.

The effect of irradiation and mass rearing on the anti-predator behaviour of the Mexican fruit fly, Anastrepha ludens (Diptera: Tephritidae)

Fruit flies (Diptera: Tephritidae) are major pests worldwide. The sterile insect technique, where millions of flies are reared, sterilized by irradiation and then released, is one of the most successful and ecologically friendly methods of controlling populations of these pests. The mating behaviour of irradiated and non-irradiated flies has been compared in earlier studies, but there has been little attention paid to the anti-predator behaviour of mass-reared flies, especially with respect to wild flies. Tephritid flies perform a supination display to their jumping spider predators in order to deter attacks. In this study, we evaluated the possibility of using this display to determine the anti-predator capabilities of mass-reared irradiated, non-irradiated flies, and wild flies. We used an arena setup and observed bouts between jumping spiders (Phidippus audax Hentz) and male Mexican fruit flies (Anastrepha ludens Loew). We show that although all flies performed a supination display to their predator, wild flies were more likely to perform a display and were significantly more successful in avoiding attack than mass-reared flies. We suggest that this interaction can be used to develop a rapid realistic method of quality control in evaluating anti-predator abilities of mass-reared fruit flies.

Vertically integrated translational studies of PDX1 as a therapeutic target for pancreatic cancer via a novel bifunctional RNAi platform

RNA interference (RNAi) represents a powerful, new tool for scientific investigation as well as a promising new form of targeted gene therapy, with applications currently in clinical trials. Bifunctional short hairpin RNA (shRNA) are synthetic RNAi molecules, engineered to utilize multiple endogenous RNAi pathways to specifically silence target genes. Pancreatic and duodenal homeobox 1 (PDX1) is a key regulator of pancreatic development, β-cell differentiation, normal β-cell function and pancreatic cancer. Our aim is to review the process of identifying PDX1 as a specific, potential RNAi target in pancreatic cancer, as well as the underlying mechanisms and various forms of RNAi, with subsequent testing and development of PDX1-targeted bifunctional shRNA therapy.

Presence or absence of intestinal metaplasia but not its burden is associated with prevalent high-grade dysplasia and cancer in Barrett's esophagus

Universal agreement on the inclusion of intestinal metaplasia to diagnose Barrett's esophagus (BE) is lacking. Our aim was to determine the association of intestinal metaplasia and its density with the prevalence of dysplasia/cancer in columnar lined esophagus (CLE). Patients with CLE but no intestinal metaplasia (CLE-no IM) were identified by querying the clinical pathology database using SNOMED codes for distal esophageal biopsies. CLE-IM patients were identified from a prospectively maintained database of BE patients. Subsequently, relative risks for prevalent dysplasia and cancer were calculated. Since patients with CLE-no IM are not usually enrolled in surveillance, only prevalent dysplasia/cancer on index endoscopy was analyzed. Goblet cell density and percent intestinal metaplasia were estimated. All biopsy slides were reviewed for dysplasia by two experienced gastrointestinal pathologists. Two hundred sixty-two CLE-IM and 260 CLE-no IM patients were included (age 64±12 vs. 60±11 years, P=0.001; whites 92% vs. 82%, P=0.001; males 99.7% vs. 99.3%, P=NS; CLE length 3.4±3.2 vears 1.4±0.4 cm, P=0.001 and hiatus hernia 64% vs. 56%, P=0.013). The odds of finding low-grade dysplasia and of high-grade dysplasia (HGD)/cancer were 12.5-fold (2.9-53.8, P=0.007) and 4.2-fold (95% CI 1.4-13, P=0.01) higher, respectively, in the CLE-IM group. Reanalysis after controlling for important variables of age, race, and length did not significantly alter the overall results. In CLE-IM group, when patients with high (>50/LPF) versus low goblet cell density (<50/LPF) and <10% versus >10% intestinal metaplasia were compared, the odds of HGD/cancer, OR 1.5 (0.5-4.9, P=0.5) and 1.97 (0.54-7.22), respectively, were not significantly higher. Demonstration of intestinal metaplasia continues to be an essential element in the definition of BE, but its quantification may not be useful for risk stratification of HGD/cancer in BE.

Social support mediates the relationship between HIV stigma and depression/quality of life among people living with HIV in Beijing, China

Stigma towards people living with HIV is pervasive in China and related to poor service utilization, psychosocial distress and diminished quality of life (QOL). In an effort to identify mechanisms to reduce HIV stigma and its negative consequences, we examined whether social support mediates the relation between enacted stigma and both depressive symptoms and QOL among 120 HIV outpatients in Beijing, China. Generally, perceived social support was associated with less stigma, less depressive symptomatology and better QOL. Using multivariable regression models, we found that social support was a full mediator of the impact of stigma on both depressive symptomatology and QOL. The findings suggest social support may be an important target of interventions to reduce the impact of stigma on poor psychosocial health outcomes.