Opposing GPCR signaling programs protein intake setpoint in Drosophila.

Animals defend a target level for their fundamental needs, including food, water, and sleep. Deviation from the target range, or "setpoint," triggers motivated behaviors to eliminate that difference. Whether and how the setpoint itself is encoded remains enigmatic for all motivated behaviors. Employing a high-throughput feeding assay in Drosophila, we demonstrate that the protein intake setpoint is set to different values in male, virgin female, and mated female flies to meet their varying protein demands. Leveraging this setpoint variability, we found, remarkably, that the information on the intake setpoint is stored within the protein hunger neurons as the resting membrane potential. Two RFamide G protein-coupled receptor (GPCR) pathways, by tuning the resting membrane potential in opposite directions, coordinately program and adjust the protein intake setpoint. Together, our studies map the protein intake setpoint to a single trackable physiological parameter and elucidate the cellular and molecular mechanisms underlying setpoint determination and modulation.

Phase separation of YAP-MAML2 differentially regulates the transcriptome.

Phase separation (PS) drives the formation of biomolecular condensates that are emerging biological structures involved in diverse cellular processes. Recent studies have unveiled PS-induced formation of several transcriptional factor (TF) condensates that are transcriptionally active, but how strongly PS promotes gene activation remains unclear. Here, we show that the oncogenic TF fusion Yes-associated protein 1-Mastermind like transcriptional coactivator 2 (YAP-MAML2) undergoes PS and forms liquid-like condensates that bear the hallmarks of transcriptional activity. Furthermore, we examined the contribution of PS to YAP-MAML2-mediated gene expression by developing a chemogenetic tool that dissolves TF condensates, allowing us to compare phase-separated and non-phase-separated conditions at identical YAP-MAML2 protein levels. We found that a small fraction of YAP-MAML2-regulated genes is further affected by PS, which include the canonical YAP target genes CTGF and CYR61, and other oncogenes. On the other hand, majority of YAP-MAML2-regulated genes are not affected by PS, highlighting that transcription can be activated effectively by diffuse complexes of TFs with the transcriptional machinery. Our work opens new directions in understanding the role of PS in selective modulation of gene expression, suggesting differential roles of PS in biological processes.

Visualizing Dynamics of Cell Signaling In Vivo with a Phase Separation-Based Kinase Reporter.

Visualizing dynamics of kinase activity in living animals is essential for mechanistic understanding of cell and developmental biology. We describe GFP-based kinase reporters that phase-separate upon kinase activation via multivalent protein-protein interactions, forming intensively fluorescent droplets. Called SPARK (separation of phases-based activity reporter of kinase), these reporters have large dynamic range (fluorescence change), high brightness, fast kinetics, and are reversible. The SPARK-based protein kinase A (PKA) reporter reveals oscillatory dynamics of PKA activities upon G protein-coupled receptor activation. The SPARK-based extracellular signal-regulated kinase (ERK) reporter unveils transient dynamics of ERK activity during tracheal metamorphosis in live Drosophila. Because of intensive brightness and simple signal pattern, SPARKs allow easy examination of kinase signaling in living animals in a qualitative way. The modular design of SPARK will facilitate development of reporters of other kinases.

Project S.T.O.P (Stop the Over-ordering of Platelets): An initiative to reduce platelet wastages for pediatric open-heart surgeries.

INTRODUCTION: Due to a national policy change in the management of unused platelet units from September 2018, there was a drastic increase in the number of platelet units wasted in our institution. METHODS: Using Quality Improvement (QI) tools, platelet wastages from pediatric heart surgeries was identified as a priority area to work on. An intervention based on the creation of 'Order Sets' for pediatric open-heart surgeries was implemented, standardizing standby platelet orders based on type of surgery and patient weight. RESULTS: This intervention led to a dramatic improvement in the number of platelets ordered on standby, and consequently a decrease in platelet wastage from 47.6% to 16.9% for pediatric open-heart surgeries, without any reported adverse events. CONCLUSION: With the creation of Order Sets and continuous education, it was possible to eradicate the practice of requesting unnecessary standby platelets for surgeries. This is an effective patient blood management (PBM) strategy resulting in a significant decrease in platelet wastage rate and substantial cost savings.

DNA-induced 2'3'-cGAMP enhances haplotype-specific human STING cleavage by dengue protease.

The cytosolic DNA sensor cGMP-AMP synthase (cGAS) synthesizes the noncanonical cyclic dinucleotide 2'3'-cGAMP to activate the adaptor protein stimulator of IFN genes (STING), thus awakening host immunity in response to DNA pathogen infection. However, dengue virus (DENV), an RNA virus without a DNA stage in its life cycle, also manipulates cGAS-STING-mediated innate immunity by proteolytic degradation of STING. Here, we found that the sensitivity of STING to DENV protease varied with different human STING haplotypes. Exogenous DNA further enhanced DENV protease's ability to interact and cleave protease-sensitive STING. DNA-enhanced STING cleavage was reduced in cGAS-knockdown cells and triggered by the cGAS product 2'3'-cGAMP. The source of DNA may not be endogenous mitochondrial DNA but rather exogenous reactivated viral DNA. Cells producing 2'3'-cGAMP by overexpressing cGAS or with DNA virus reactivation enhanced STING cleavage in neighboring cells harboring DENV protease. DENV infection reduced host innate immunity in cells with the protease-sensitive STING haplotype, whose homozygote genotype frequency was found significantly reduced in Taiwanese people with dengue fever. Therefore, the human STING genetic background and DNA pathogen coinfection may be the missing links contributing to DENV pathogenesis.

Comparison of the O-RADS and ADNEX models regarding malignancy rate and validity in evaluating adnexal lesions.

OBJECTIVE: This study aimed to compare the ability of the O-RADS and ADNEX models to classify benign or malignant adnexal lesions. METHODS: This retrospective single-center study included women who underwent surgery for adnexal lesions. Two gynecologists independently categorized the adnexal lesions according to the O-RADS and ADNEX models. Four additional readers were included to validate the new quick-access O-RADS flowchart. RESULTS: Among the 322 patients included in this study, 264 (82.0%) had a benign diagnosis, and 58 (18.0%) had a malignant diagnosis. The malignant rates of O-RADS 2, O-RADS 3, O-RADS 4, and O-RADS 5 were 0%, 3.0%, 37.7%, and 78.9%, respectively. The AUC of the O-RADS in the 322 patients was 0.93. On comparing the O-RADS and ADNEX models in the remaining 281 patients, the AUCs of the O-RADS, ADNEX model with CA125, and ADNEX model without CA125 were 0.92, 0.95, and 0.94, respectively. When setting a uniform cutoff of ≥ 10% (≥ O-RADS 4) to predict malignancy, the O-RADS had higher sensitivity than the ADNEX model (96.6% vs. 91.4%), and relatively similar specificity. In addition, the readers with the quick-access flowchart spent less time categorizing O-RADS than the readers with only the original O-RADS table (mean analysis time: 99 min 15 s vs. 111 min 55 s). CONCLUSIONS: The O-RADS classification of the adnexal lesions as benign or malignant was comparable to that of the ADNEX model and had higher sensitivity at the 10% cutoff value. A quick-access O-RADS flowchart was helpful in O-RADS categorization and might shorten the analysis time. KEY POINTS: • Both O-RADS and ADNEX models had good diagnostic performance in distinguishing adnexal malignancy, and O-RADS had higher sensitivity than ADNEX model in uniform 10% cutoff to predict malignancy. • Quick-access O-RADS flowchart was developed to help review O-RADS classification and might help reduce the analysis time.

Efficacy and Safety of "I-Stop-Mini Adjustable" Sling System versus Transobturator Midurethral "Obtryx" Sling System in Stress Urinary Incontinence: A Retrospective Cohort Study.

STUDY OBJECTIVE: To compare the safety, efficacy, and adverse events of the new mini-adjustable sling system "I-stop-mini" with transobturator midurethral slings "Obtryx" (Boston Scientific, Marlborough, MA) in women with stress urinary incontinence. DESIGN: A single-center, retrospective cohort study. SETTING: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taiwan. PATIENTS: A total of 347 patients who underwent I-stop-mini or Obtryx for stress urinary incontinence treatment. INTERVENTIONS: Midurethral sling with either I-stop-mini or Obtryx. MEASUREMENTS AND MAIN RESULTS: The primary outcomes were objective success and subjective cure rates between the 2 groups. Objective success was evaluated using a 1-hour pad test, and subjective cure was evaluated using a questionnaire score (Incontinence Impact Questionnaire, Urinary Distress Inventory, and International Consultation on Incontinence Questionnaire Short Form). Secondary outcomes were the evaluation of surgical outcomes, operative data, and adverse events between the 2 groups. In total, 171 of 200 I-stop-mini subjects and 127 of 147 Obtryx subjects completed 12 months of follow-up. Regarding the objective success between the I-stop-mini group and the Obtryx group, 1-month postoperative (3.6 ± 5.2 vs 3.9 ± 12.6; p = .765), 6-month postoperative (3.9 ± 5.1 vs 4.2 ± 12.6; p = .848), and 12-month postoperative (4.6 ± 5.6 vs 4.5 ± 13.6; p = .980) 1-hour pad tests showed no significant difference. The 12-month subjective cure rates decreased from 94.7% (1-month postoperative) to 91.2% (12-month postoperative) in the I-stop-mini group and 95.2% (1-month postoperative) to 85.0% (12-month postoperative) in the Obtryx group. Similar and durable efficacy was observed between the 2 groups. The I-stop-mini group had shorter operative times and hospital stays than the Obtryx group; however, both groups showed similar adverse event rates. CONCLUSION: The objective success and subjective cure rates of I-stop-mini did not differ to those of Obtryx. However, long-term data and further prospective studies on I-stop-mini are necessary to arrive at a definite conclusion.

Maintenance Therapy for Preventing Endometrioma Recurrence after Endometriosis Resection Surgery - A Systematic Review and Network Meta-analysis.

OBJECTIVE: To evaluate the efficacy of different hormone therapies in preventing postoperative endometrioma recurrence. DATA SOURCES: The MEDLINE, COCHRANE, and Embase electronic databases were searched from inception to 30 April 2021. METHODS OF STUDY SELECTION: Randomized controlled trials (RCTs) or cohort studies including reproductive age women with endometriosis undergoing ovarian cystectomy or excision of endometriotic lesions compared the effects of postoperative adjuvant therapy (gonadotropin-releasing hormone agonist [GnRHa]) and postoperative maintenance hormone interventions for more than 1 year (i.e., oral contraceptive pills [OCPs], dienogest [DNG], levonorgestrel-releasing intrauterine system [LNGIUS]) on endometrioma recurrence. TABULATION, INTEGRATION, AND RESULTS: Data collection and analysis of the data were independently performed 2 two reviewers. A total of 11 studies were included, of which 2 were RCTs, and 9 were cohort studies. There were 2394 patients with 6 interventions (cases: 1665, 69.6%) and expectant management (cases: 729, 30.4%). Relative treatment effects were estimated using network meta-analysis and ranked in descending order. The clinical effectiveness of these drugs (vs expectant management) was as follows: GnRHa plus DNG (odds ratio [OR], 0.04; 95% confidence interval [CI], 0.01-0.27), surface under the cumulative ranking (SUCRA) = 94.0; DNG (OR, 0.11; 95% CI, 0.04-0.32), SUCRA = 69.7; GnRHa plus OCP (OR, 0.12; 95% CI, 0.02-0.64), SUCRA = 63.4; GnRHa plus LNGIUS (OR, 0.13; 95% CI, 0.03-0.66), SUCRA = 59.4; and OCP (OR, 0.21; 95% CI, 0.13-0.36), SUCRA = 43.6. The effectiveness of GnRHa (OR, 0.47; 95% CI, 0.12-1.89), SUCRA = 17.3 was not significantly different from that of controls. CONCLUSION: In network meta-analysis, combined postoperative adjuvant therapy and longer maintenance hormone treatment are better than a single agent in preventing postoperative endometrioma recurrence. GnRHa plus DNG maintenance treatment might be the most effective intervention. Large-scale RCTs of these agents are still required.

Perception of nonnative tonal contrasts by Mandarin-English and English-Mandarin sequential bilinguals.

This study examined the role of acquisition order and crosslinguistic similarity in influencing transfer at the initial stage of perceptually acquiring a tonal third language (L3). Perception of tones in Yoruba and Thai was tested in adult sequential bilinguals representing three different first (L1) and second language (L2) backgrounds: L1 Mandarin-L2 English (MEBs), L1 English-L2 Mandarin (EMBs), and L1 English-L2 intonational/non-tonal (EIBs). MEBs outperformed EMBs and EIBs in discriminating L3 tonal contrasts in both languages, while EMBs showed a small advantage over EIBs on Yoruba. All groups showed better overall discrimination in Thai than Yoruba, but group differences were more robust in Yoruba. MEBs' and EMBs' poor discrimination of certain L3 contrasts was further reflected in the L3 tones being perceived as similar to the same Mandarin tone; however, EIBs, with no knowledge of Mandarin, showed many of the same similarity judgments. These findings thus suggest that L1 tonal experience has a particularly facilitative effect in L3 tone perception, but there is also a facilitative effect of L2 tonal experience. Further, crosslinguistic perceptual similarity between L1/L2 and L3 tones, as well as acoustic similarity between different L3 tones, play a significant role at this early stage of L3 tone acquisition.

Common urological problems in children: primary nocturnal enuresis.

Enuresis is a common complaint in children, with a prevalence of around 15% at age 6 years. Evidence suggests that enuresis could affect neuropsychiatric development. The condition may represent an entire spectrum of underlying urological conditions. It is important to understand the difference between monosymptomatic and non-monosymptomatic enuresis. Primary monosymptomatic enuresis can be managed efficaciously with care in different settings, like primary care, specialist nursing, or paediatric specialists, while non-monosymptomatic enuresis requires more complex evaluation and treatment. The diagnosis, investigation, and management of the two types of enuresis are discussed in this review.

Dynamic Imaging of Small Molecule Induced Protein-Protein Interactions in Living Cells with a Fluorophore Phase Transition Based Approach.

Protein-protein interactions (PPIs) mediate signal transduction in cells. Small molecules that regulate PPIs are important tools for biology and biomedicine. Dynamic imaging of small molecule induced PPIs characterizes and verifies these molecules in living cells. It is thus important to develop cellular assays for dynamic visualization of small molecule induced protein-protein association and dissociation in living cells. Here we have applied a fluorophore phase transition based principle and designed a PPI assay named SPPIER (separation of phases-based protein interaction reporter). SPPIER utilizes the green fluorescent protein (GFP) and is thus genetically encoded. Upon small molecule induced PPI, SPPIER rapidly forms highly fluorescent GFP droplets in living cells. SPPIER detects immunomodulatory drug (IMiD) induced PPI between cereblon and the transcription factor Ikaros. It also detects IMiD analogue (e.g., CC-885) induced PPI between cereblon and GSPT1. Furthermore, SPPIER can visualize bifunctional molecules (e.g. PROTAC)-induced PPI between an E3 ubiquitin ligase and a target protein. Lastly, SPPIER can be modified to image small molecule induced protein-protein dissociation, such as nutlin-induced dissociation between HDM2 and p53. The intense brightness and rapid kinetics of SPPIER enable robust and dynamic visualization of PPIs in living cells.

Comparison of lesional skin c-KIT mutations with clinical phenotype in patients with mastocytosis.

BACKGROUND: Activating c-KIT mutations cause abnormal mast cell growth and appear to play a role in mastocytosis. However, the correlation of c-KIT mutations with disease phenotypes is poorly characterized. AIM: To evaluate the correlation of c-KIT mutations with clinical presentations and laboratory findings. METHODS: Total cellular RNA was isolated from the skin lesions of 43 adults and 7 children with mastocytosis, and PCR amplicons of cDNA were sequenced for c-KIT mutations. RESULTS: The most common activating mutation, KIT-D816V, was identified in 72% of adults and 57% of children. Additional activating mutations, namely, V560G and the internal tandem duplications (ITDs) 502-503dupAY, were detected in 12% of adults and 8% of children. V560G occurred more commonly in our patients than previously reported, and it appeared to be associated with more advanced disease. Otherwise, the presence or absence of activating mutations did not correlate with skin lesion morphology, disease extent or total serum tryptase levels. Four adults had expression only of wild-type KIT, while two others had expression of a truncated KIT lacking tyrosine kinase activity; yet these patients were clinically indistinguishable from those patients with activating c-KIT mutations. CONCLUSIONS: Activating c-KIT mutations exist in a significant portion of patients with mastocytosis, but not all patients showed expression of these mutations. Except for V560G, the presence or absence of activating c-KIT mutations did not predict the extent of disease. These observations suggest that although activating c-KIT mutations are associated with mast cell growth, other genes probably play a role in the cause of mastocytosis.

Role of the RAD51-SWI5-SFR1 Ensemble in homologous recombination.

During DNA double-strand break and replication fork repair by homologous recombination, the RAD51 recombinase catalyzes the DNA strand exchange reaction via a helical polymer assembled on single-stranded DNA, termed the presynaptic filament. Our published work has demonstrated a dual function of the SWI5-SFR1 complex in RAD51-mediated DNA strand exchange, namely, by stabilizing the presynaptic filament and maintaining the catalytically active ATP-bound state of the filament via enhancement of ADP release. In this study, we have strived to determine the basis for physical and functional interactions between Mus musculus SWI5-SFR1 and RAD51. We found that SWI5-SFR1 preferentially associates with the oligomeric form of RAD51. Specifically, a C-terminal domain within SWI5 contributes to RAD51 interaction. With specific RAD51 interaction defective mutants of SWI5-SFR1 that we have isolated, we show that the physical interaction is indispensable for the stimulation of the recombinase activity of RAD51. Our results thus help establish the functional relevance of the trimeric RAD51-SWI5-SFR1 complex and provide insights into the mechanistic underpinnings of homology-directed DNA repair in mammalian cells.

Title.

Epilepsy is defined as drug-resistant after failure of two adequate trials of appropriately chosen and administered antiepileptic drugs. Approximately 30% of patients with epilepsy have drug-resistant epilepsy. Reasons for treatment failure include failure to recognise epilepsy syndrome, poor drug compliance, and lifestyle factors. Patients with drug-resistant epilepsy should be encouraged to have early referral to a tertiary epilepsy centre for presurgical evaluation. Comprehensive neurophysiology, structural neuroimaging, neuropsychological, and psychiatric assessments are regarded as essential for determining suitability for epilepsy surgery. Epilepsy surgery, whether resection, disconnection, or neuromodulation, should be recommended only after multidisciplinary consensus agreement based on these assessments.

Development of a Quenchbody for the Detection and Imaging of the Cancer-Related Tight-Junction-Associated Membrane Protein Claudin.

Claudins (CLs) are membrane proteins found in tight junctions and play a major role in establishing the intercellular barrier. However, some CLs are abnormally overexpressed on tumor cells and are valid clinical biomarkers for cancer diagnosis. Here, we constructed antibody Fab fragment-based Quenchbodies (Q-bodies) as effective and reliable fluorescent sensors for detecting and visualizing CLs on live tumor cells. The variable region genes for anti-CL1 and anti-CL4 antibodies were used to express recombinant Fab fragments, and clones recognizing CL4 with high affinity were selected for making Q-bodies. When two fluorescent dyes were conjugated to the N-terminal tags attached to the Fab, the fluorescent signal was significantly increased after adding nanomolar-levels of purified CL4. Moreover, addition of the Q-body to CL4-expressing cells including CL4-positive cancer cells led to a clear fluorescence signal with low background, even without washing steps. Our findings suggested that such Q-bodies would serve as a potent tool for specifically illuminating membrane targets expressed on cancer cells, both in vitro and in vivo.

SUMO Modification Stabilizes Dengue Virus Nonstructural Protein 5 To Support Virus Replication.

UNLABELLED: Small ubiquitin-like modifier (SUMO) participates in a reversible posttranslational modification process (SUMOylation) that regulates a wide variety of cellular processes and plays important roles for numerous viruses during infection. However, the roles of viral protein SUMOylation in dengue virus (DENV) infection have not been elucidated. In this study, we found that the SUMOylation pathway was involved in the DENV life cycle, since DENV replication was reduced by silencing the cellular gene Ubc9, which encodes the sole E2-conjugating enzyme required for SUMOylation. By in vivo and in vitro SUMOylation assays, the DENV NS5 protein was identified as an authentic SUMO-targeted protein. By expressing various NS5 mutants, we found that the SUMO acceptor sites are located in the N-terminal domain of NS5 and that a putative SUMO-interacting motif (SIM) of this domain is crucial for its SUMOylation. A DENV replicon harboring the SUMOylation-defective SIM mutant showed a severe defect in viral RNA replication, supporting the notion that NS5 SUMOylation is required for DENV replication. SUMOylation-defective mutants also failed to suppress the induction of STAT2-mediated host antiviral interferon signaling. Furthermore, the SUMOylation of NS5 significantly increased the stability of NS5 protein, which could account for most of the biological functions of SUMOylated NS5. Collectively, these findings suggest that the SUMOylation of DENV NS5 is one of the mechanisms regulating DENV replication. IMPORTANCE: SUMOylation is a common posttranslational modification that regulates cellular protein functions but has not been reported in the proteins of dengue virus. Here, we found that the replicase of DENV, nonstructural protein 5 (NS5), can be SUMOylated. It is well known that providing RNA-dependent RNA polymerase activity and antagonizing host antiviral IFN signaling are a "double indemnity" of NS5 to support DENV replication. Without SUMOylation, NS5 fails to maintain its protein stability, which consequently disrupts its function in viral RNA replication and innate immunity antagonism. DENV threatens billions of people worldwide, but no licensed vaccine or specific therapeutics are currently available. Thus, our findings suggest that rather than specifically targeting NS5 enzyme activity, NS5 protein stability is a novel drug target on the growing list of anti-DENV strategies.

Dengue Virus Impairs Mitochondrial Fusion by Cleaving Mitofusins.

Mitochondria are highly dynamic subcellular organelles participating in many signaling pathways such as antiviral innate immunity and cell death cascades. Here we found that mitochondrial fusion was impaired in dengue virus (DENV) infected cells. Two mitofusins (MFN1 and MFN2), which mediate mitochondrial fusion and participate in the proper function of mitochondria, were cleaved by DENV protease NS2B3. By knockdown and overexpression approaches, these two MFNs showed diverse functions in DENV infection. MFN1 was required for efficient antiviral retinoic acid-inducible gene I-like receptor signaling to suppress DENV replication, while MFN2 participated in maintaining mitochondrial membrane potential (MMP) to attenuate DENV-induced cell death. Cleaving MFN1 and MFN2 by DENV protease suppressed mitochondrial fusion and deteriorated DENV-induced cytopathic effects through subverting interferon production and facilitating MMP disruption. Thus, MFNs participate in host defense against DENV infection by promoting the antiviral response and cell survival, and DENV regulates mitochondrial morphology by cleaving MFNs to manipulate the outcome of infection.

An open sandwich immunoassay for detection of 13(R,S)-hydroxy-9(E),11(E)-octadecadienoic acid.

Lipid peroxidation is involved in many disorders and diseases such as cardiovascular disease, cancers, neurodegenerative diseases, and even aging. Lipid peroxidation products existing in blood or bodily fluids are very important biomarkers for the diagnosis of such diseases. In particular, 13(R,S)-hydroxy-9(E),11(E)-octadecadienoic acid (13-(E,E)-HODE) is an oxidiation product of linoleic acid, which is an important biomarker for many diseases such as diabetes and Alzheimer's disease. In this study, we successfully displayed the antigen-binding fragment of an antibody produced by hybridoma 1213-1 on the M13 phage and performed analysis of the antibody variable region genes. The blast results suggested that it is a novel antibody. We also developed a phage-antibody-based competitive ELISA and a novel Open Sandwich ELISA (OS ELISA) for the detection of 13-(E,E)-HODE. The OS ELISA showed a limit of detection (LOD) of 15.6 nM of 13-(E,E)-HODE and low cross-reactivity with other HODE such as 9-(E,E)-HODE. Another format of the open sandwich ELISA with purified maltose binding protein-fused VL and VH-phage showed a lower LOD of 2.2 nM of 13-(E,E)-HODE, which may be sensitive enough to detect the concentration of 13-(E,E)-HODE in patients' blood samples. This is the first OS ELISA for the detection of lipids, and we believe it also represents the first molecular cloning of anti-HODE antibody genes.

Do men and women with intellectual disabilities understand death?

BACKGROUND: Individuals with ID are often withheld information about the death of their loved ones as it has often been thought that they do not understand death or cannot grieve. This grief exacerbates the stress of individuals with ID as they often encounter secondary losses such as transitioning to a care facility. The aim of this study is to investigate men and women with ID understanding death concepts and to what extent. METHOD: Adopting a stratified random sampling method, 156 Chinese people with ID were invited to join the study. One hundred and ten participants were interviewed using simple death related vignettes expanding upon and replicating a published study carried out in Ireland. The understanding of the five death concepts: causality, irreversibility, nonfunctionality, universality and inevitability was examined. The correlates of demographics, bereavement experiences and comprehension were explored. RESULTS: The majority of the participants did understand concepts such as death is irreversible and that the deceased no longer function. One third of the participants understood causality and the universality of death. One fifth understood the inevitability of death. Previous bereavement experiences were correlated with higher understanding. Communication and community skills were correlated with all concepts of death except universality. CONCLUSION: The results indicate that individuals with ID do have a partial to full understanding of the concepts of death. The culture of Hong Kong is one that considers death to be a taboo or unlucky subject. Therefore, the results mirror the the lack of understanding of universality and inevitability concepts as it is forbidden to speak of these concepts. An open and honest environment is encouraged to educate individuals with ID about death and bereavement.