Belief that addiction is a discrete category is a stronger correlate with stigma than the belief that addiction is biologically based

BACKGROUND

Drug addiction is stigmatized, and this stigma contributes to poor outcomes for individuals with addiction. Researchers have argued that providing genetic explanations of addiction will reduce stigma, but there has been limited research testing this prediction.

METHODS

We presented participants (N = 252) with news articles that either provided genetic or anti-genetic explanations of addiction.

RESULTS

There was no effect of article condition on stigma. Participants' biological essentialism correlated with stigma in the context of both opioid and methamphetamine addiction. However, participants' non-biological essentialism was a significantly stronger correlate with stigma.

CONCLUSIONS

This suggests that other essentialist beliefs, like belief that categories are discrete, may be more useful than biological essentialism for understanding addiction stigma.

Use of remdesivir for COVID-19 pneumonia in patients with advanced kidney disease: A retrospective multicenter study

Background and objectives

Remdesivir, an antiviral drug routinely used in the treatment of COVID-19 has not yet received FDA approval for use in patients with advanced kidney disease defined as GFR < 30 mL/min/1.73 m². There is concern that an excipient in Veklury (Gilead's proprietary name for remdesivir) called sulfobutylether-beta-cyclodextrin (SBECD), which is renally cleared, may accumulate and reach toxic levels in patients with advanced kidney disease. The aim of this study was to summarize characteristics and incidence of adverse events of chronic kidney disease (CKD) patients who received remdesivir during hospitalization.Design, setting, participants, and measurements.We retrospectively studied patients admitted to one of several hospitals of the Mayo Clinic Foundation with the diagnosis of COVID-19 pneumonia and CKD. Laboratory values were also measured when remdesivir was first administered and stopped. All analyses were performed in the overall patient group and three separate subgroups of patients with a GFR ≥ 15, a GFR < 15 and dialysis, and a GFR < 15 and no dialysis.

Results

A total of 444 CKD patients who were admitted to the hospital with COVID-19 pneumonia between May 2020 and September 2021 were included. Information was collected on patient characteristics, hospitalization, and adverse events. In the overall cohort, median age was 72 years (Range: 21-100 years), 55.2 % of patients were male, and most (86.5 %) were Caucasian. CKD stage was 3 for 114 patients (25.7 %), 4 for 229 patients (51.6 %), and 5 for 101 patients (22.7 %). A total of 146 patients (32.9 %) were admitted to the ICU, 103 (23.2 %) died in the hospital, and 120 (27.0 %) were on dialysis. The proportion of patients with an adverse event did not differ dramatically between the GFR ≥ 15 (20.9 %), GFR < 15 and dialysis (30.2 %), and GFR < 15 and no dialysis (32.3 %) groups (P = 0.12).

Conclusion

Our results suggest that the use of remdesivir in patients with very severe CKD is safe, even in those who are not on renal replacement therapy.

Periopathogens Modulate Inflammation by Repressing miR-142-3p and Augmenting miR-155/NFκB axis

MicroRNA (miR) play a critical role in the pathogenesis of immune-mediated diseases. We hypothesize that periopathogens (P. gingivalis [Pg] and A. actinomycemtemcomitans [Aa]) impair host immune response by perturbing miR expression. Periopathogen burden, cytokine and miR expression was quantified by qPCR in healthy and inflamed human gingival biopsies. Human primary CD14+ monocytes were differentiated to M1 or M2 macrophages (MΦ) and challenged with live Pg or Aa to monitor expression profiles of pro- and anti-inflammatory miRs by qPCR. Supernatant levels of cytokines were assessed by multiplex bead assay while, protein levels were quantified by western blot. Murine gingival miRNA and mRNA profiles were validated during disease progression in a liguture-induced periodontitis model and bone loss measured by microCT. Higher periopathogen burden and inflammatory cytokine expression was observed in inflamed gingiva with a higher expression of pro-inflammatory miR-155 and reduced levels of anti-inflammatory miR-142-3p. This corroborates with NFκB activation and downregulation of PU.1 suggesting a distinct role of a miR and transcription factor (TF) axis. miR-155-mediated downregulation of PU.1, a TF of miR-142, suppressed transcription of miR-142, thereby alleviating silencing of IL-6 mediated by miR-142-3p. Our murine ligature model showed progressive bone loss in the presence of Pg and higher expression of cytokine profiles. Local delivery of miR-142-3p showed reduction in IL-6. Periopathogen-mediated activation of miR-155/NFκB axis augments inflammatory signaling by decreasing levels of PU.1 and expression of its target miR-142. This mechanism may be critical in the pathogenesis of periodontal disease.

Supported by R01 DE027980, R21 DE026259, R03 DE027147

Distinct Biological Motion Perception in Autism Spectrum Disorder: A Meta-Analysis

If neurotypical people rely on specialized perceptual mechanisms when perceiving biological motion, then one would not expect an association between task performance and IQ. However, if those with ASD recruit higher order cognitive skills when solving biological motion tasks, performance may be predicted by IQ. In a meta-analysis that included 19 articles, we found an association between biological motion perception and IQ among observers with ASD but no significant relationship among typical observers. If the task required emotion perception, then there was an even stronger association with IQ in the ASD group.

Effect of sciatic nerve mobilisation on muscle flexibility among diabetic and non-diabetic sedentary individuals: a comparative study

The purpose of the present study was to compare the effect of sciatic nerve mobilisation on muscle flexibility among diabetic and non-diabetic sedentary individuals. The study was a pre-post experimental-group design. A sample of 40 sedentary subjects was assigned into two groups; Group A (diabetics: 10 males and 10 females) and Group B (non-diabetics: 10 males and 10 females). Both groups were tested for hamstring and calf flexibility following which sciatic nerve mobilisation was given to the most affected lower limb in terms of reduced hamstring and calf flexibility. Hamstring flexibility was checked by active knee extension test and calf flexibility was checked with the distance-to-wall technique using a tape measure. It was a two-week program in which subjects were given sciatic nerve mobilisation using sliders technique after which flexibility was checked. Three sessions per week were given for two weeks and muscle flexibility of hamstring and calf was measured after the intervention. The present study findings reveal that sciatic nerve mobilisation by sliders technique when given to diabetic and non-diabetic groups of sedentary individuals for two weeks, enhance patient outcomes in both the groups in terms of increase in hamstring and calf flexibility, but results were more significant in non-diabetic individuals as compared to diabetic individuals. In conclusion, sciatic nerve mobilisation resulted in an increase of muscle flexibility of hamstring and calf muscles in both groups.

Early Attention to Animacy: Change-Detection in 11-Month-Olds

Adults are faster and more accurate at detecting changes to animate compared to inanimate stimuli in a change-detection paradigm. We tested whether 11-month-old children detected changes to animate objects in an image more reliably than they detected changes to inanimate objects. During each trial, infants were habituated to an image of a natural scene. Once the infant habituated, the scene was replaced by a scene that was identical except that a target object was removed. Infants dishabituated significantly more often if an animate target had been removed from the scene. Dishabituation results suggested that infants, like adults, preferentially attend to animate rather than to inanimate objects.

Viral MicroRNAs: Interfering the Interferon Signaling

Interferons are secreted cytokines with potent antiviral, antitumor and immunomodulatory functions. As the first line of defense against viruses, this pathway restricts virus infection and spread. On the contrary, viruses have evolved ingenious strategies to evade host immune responses including the interferon pathway. Multiple families of viruses, in particular, DNA viruses, encode microRNA (miR) that are small, non-protein coding, regulatory RNAs. Virus-derived miRNAs (v-miR) function by targeting host and virus-encoded transcripts and are critical in shaping host-pathogen interaction. The role of v-miRs in viral pathogenesis is emerging as demonstrated by their function in subverting host defense mechanisms and regulating fundamental biological processes such as cell survival, proliferation, modulation of viral life-cycle phase. In this review, we will discuss the role of v-miRs in the suppression of host genes involved in the viral nucleic acid detection, JAK-STAT pathway, and cytokine-mediated antiviral gene activation to favor viral replication and persistence. This information has yielded new insights into our understanding of how v-miRs promote viral evasion of host immunity and likely provide novel antiviral therapeutic targets.

Canadian children's concepts of national groups: A comparison with children from the United States

Understanding the development and structure of people's concepts of national groups can contribute to an understanding of their behavior in the political arena, including perhaps the recent rise in nationalism and anti-immigrant sentiment. Here, we provide a developmental investigation of concepts of national groups in a sample of 5- to 8-year-old Canadian children (N = 79). Using an extensive battery of measures, we assessed the extent to which children conceive of national groups as socially constructed versus as having deeper, perhaps biological, "essences" that shape their members' physical and psychological makeup. At younger ages, Canadian children tended to essentialize national groups, including in a biological sense. At older ages, the biological conception of national groups subsided, but children continued to view these groups as meaningful and informative. A statistical comparison with 5- to 8-year-old American children's responses to the same measures (N = 70; using data from Hussak & Cimpian, 2019) revealed a great degree of overlap, despite substantial differences between the two countries in how national identity is conceived and described. These findings add an important piece to our understanding of the development of concepts of national groups. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Abstract PR02: Generation of the first genetically defined tumorigenic model of Ewing sarcoma expressing EWS-FLI1

Background: Ewing sarcoma (ES) is an undifferentiated cancer of the bone and soft tissue canonically defined by expression of EWS-FLI1 or similar fusion proteins. The cell of origin remains undefined but is likely either a human mesenchymal stem cell (hMSC) or neural crest stem cell. The ES cells are depending on EWS-FLI1 for viability, but paradoxically exogenous EWS-FLI1 expression causes cell death in virtually all other cells. Expression of EWS-FLI1 in hMSCs has been variably successful and unreliable, and the two prior reports of stable expression did not elucidate why those efforts were successful, preventing reproducibility. Our work has shown that expression of the lncRNA HOTAIR allows for subsequent stable expression of EWS-FLI1 in hTERT-immortalized hMSCs and primary hMSCs but without induction of tumorigenesis in vivo.

Methods: We used established ES cell lines, hTERT-hMSCs and primary hMSCS, to evaluate mRNA and protein expression at baseline and in the context of modulation of expression of HOTAIR, EWS-FLI1, MYC, and MYCN.

Results: We demonstrated by RT-qPCR that HOTAIR is highly expressed across all ES cell lines as compared to hTERT-hMSCs and primary hMSCS. We also found that MYC is highly expressed in most ES cells lines and hMSCs. In contrast, MYCN is overexpressed in ES cell lines as compared to hMSCs. Repression of MYC in ES cell lines had no significant effect on proliferation of ES cells in vitro; repression of MYCN by shRNA in ES cell lines decreased proliferation in vitro and slowed tumor growth in vivo. Exogenous expression of HOTAIR in hMSCs allowed for viable subsequent expression of EWS-FLI1 in those cells, but without tumorigenesis in vivo (0/10 for hTERT- or primary hMSCs). Overexpression of MYC (0/6) or MYCN (1/6) in hMSCs expression HOTAIR did not reliably induce tumorigenesis. Overexpression of MYC or MYCN in hMSCs did not allow for viable EWS-FLI1 expression. Overexpression of HOTAIR, then EWS-FLI1 and MYCN, to levels comparable with ES cell lines, induced tumorigenesis from hTERT-hMSCS and primary hMSCs (6/6 for each), when cells were implanted subcutaneously into SCID mice with Matrigel. The resultant tumors were positive by immunohistochemistry for CD99 and NKX2.2, clinical markers of ES. RNA-Seq demonstrated the HOTAIR-EWS-FLI1-MYCN expressing hMSCs had gene expression profiles comparable to ES tumors.

Conclusions: We have generated the first genetically defined tumorigenic models of ES from non-neoplastic human cells. This model can be used to elucidate the biology of EWS-FLI1 in malignant transformation and tumor formation. This work supports our prior data demonstrating a necessary role for HOTAIR in ES biology and suggests that MYCN may also be a driver of tumorigenesis in ES. Additional work is needed to define the underlying factors that induce HOTAIR and MYCN expression in ES (i.e., are they basally or aberrantly expressed in the cell of origin?) and if they are therapeutically targetable.

This abstract is also being presented as Poster B77.

Citation Format: Joshua Felgenhauer, Laura Tomino, Hasan Siddiqui, Emily Bopp, Julia Selich-Anderson, Jessica Mormol, Cenny Taslim, Nilay Shah. Generation of the first genetically defined tumorigenic model of Ewing sarcoma expressing EWS-FLI1 [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr PR02.

The surgical treatment of Balanitis Xerotica Obliterans

Background: Balanitis Xerotica Obliterans (BXO) is a chronic, often progressive disease, which can lead to phimosis and urethral stenosis, affecting both urinary and sexual function. Steroid creams are usually the first-line treatment but have a limited role and surgical intervention is frequently necessary. Conservative surgical procedures (circumcision) are often preferred in the first instance with the premise that recurrence of disease will require a more definitive reconstruction. This study looked at patients with pathologically proven BXO referred to the Plastic Surgery Unit at James Cook University Hospital between 2005 and 2009. The aim was to look at their management in the past and subsequent management by us. We also looked at whether early referral of progressive and recurrent BXO patients to reconstructive surgery could have prevented unnecessary delay in resolving symptoms at an earlier stage. Materials and Methods: Data was collected retrospectively and information regarding the exact anatomical location affected, the extent of the disease, the referring specialty and any previous surgical interventions was obtained. Alterations in urinary and sexual function and relief of symptoms following reconstructive surgery were analysed. Results: Of the 23 patients in the study, 43% had previous surgery and 60% of those had undergone two or more procedures. Twenty-one percent of patients had a history of BXO for over five years. Forty-seven percent of patients had alteration in their urinary function and 48% alteration in their sexual function due to the disease, prior to referral. Early results showed remarkable improvement in urinary and sexual function following reconstructive surgery in this group. Conclusions: Steroid creams have been shown to limit the progression of the disease but do not offer a cure in the majority of cases. Circumcision can be a curative procedure in early disease. Although there is conflicting evidence for treatment of recurring urethral strictures, repeated urethrotomy or urethral dilatation has poor long-term outcome. In patients with recurrent disease and associated complications we propose early referral to a plastic surgeon with genitourinary interest or reconstructive urologist for definitive treatment.

Labelling faces as 'Autistic' reduces the inversion effect

Does the belief that a face belongs to an individual with autism affect recognition of that face? To address this question, we used the inversion effect as a marker of face recognition. In Experiment 1, participants completed a recognition task involving upright and inverted faces labelled as either 'regular' or 'autistic'. In reality, the faces presented in both conditions were identical. Results revealed a smaller inversion effect for faces labelled as autistic. Thus, simply labelling a face as 'autistic' disrupts recognition. Experiment 2 showed a larger inversion effect after the provision of humanizing versus dehumanizing information about faces labelled as 'autistic'. We suggest changes in the inversion effect could be used as a measure to study stigma within the context of objectification and dehumanization.

A portable platform to collect and review behavioral data simultaneously with neurophysiological signals

This paper presents a portable platform to collect and review behavioral data simultaneously with neurophysiological signals. The whole system is comprised of four parts: a sensor data acquisition interface, a socket server for real-time data streaming, a Simulink system for real-time processing and an offline data review and analysis toolbox. A low-cost microcontroller is used to acquire data from external sensors such as accelerometer and hand dynamometer. The micro-controller transfers the data either directly through USB or wirelessly through a bluetooth module to a data server written in C++ for MS Windows OS. The data server also interfaces with the digital glove and captures HD video from webcam. The acquired sensor data are streamed under User Datagram Protocol (UDP) to other applications such as Simulink/Matlab for real-time analysis and recording. Neurophysiological signals such as electroencephalography (EEG), electrocorticography (ECoG) and local field potential (LFP) recordings can be collected simultaneously in Simulink and fused with behavioral data. In addition, we developed a customized Matlab Graphical User Interface (GUI) software to review, annotate and analyze the data offline. The software provides a fast, user-friendly data visualization environment with synchronized video playback feature. The software is also capable of reviewing long-term neural recordings. Other featured functions such as fast preprocessing with multithreaded filters, annotation, montage selection, power-spectral density (PSD) estimate, time-frequency map and spatial spectral map are also implemented.

Upregulation of long noncoding RNA MIAT in aggressive form of chronic lymphocytic leukemias

Long noncoding RNAs (lncRNAs) are non-proten-coding transcripts of more than 200 nucleotides generated by RNA polymerase II and their expressions are tightly regulated in cell type specific- and/or cellular differential stage specific- manner. MIAT, originally isolated as a candidate gene for myocardial infarction, encodes lncRNA (termed MIAT). Here, we determined the expression level of MIAT in established leukemia/lymphoma cell lines and found its upregulation in lymphoid but not in myeloid cell lineage with mature B cell phenotype. MIAT expression level was further determined in chronic lymphocytic leukemias (CLL), characterized by expansion of leukemic cells with mature B phenotype, to demonstrate relatively high occurrence of MIAT upregulation in aggressive form of CLL carrying either 17p-deletion, 11q-deletion, or Trisomy 12 over indolent form carrying 13p-deletion. Furthermore, we show that MIAT constitutes a regulatory loop with OCT4 in malignant mature B cell, as was previously reported in mouse pulripotent stem cell, and that both molecules are essential for cell survival.

Multi-disciplinary management of complex pressure sore reconstruction: 5-year review of experience in a spinal injuries centre

INTRODUCTION In our regional spinal injuries unit, complex pressure ulcer reconstruction is facilitated by a monthly multidisciplinary team clinic. This study reviews a series of the more complex of these patients who underwent surgery as a joint case between plastics and other surgical specialties, aiming to provide descriptive data as well as share the experience of treating these complex wounds. MATERIALS AND METHODS Patients operated on as a joint case from 2010 to 2014 were identified through a locally held database and hospital records were then retrospectively reviewed for perioperative variables. Descriptive statistics were collected. RESULTS 12 patients underwent 15 procedures as a joint collaboration between plastic surgery and other surgical specialties: one with spinal surgery, 12 with orthopaedic and two with both orthopaedic and urology involvement. Ischial and trochanteric wounds accounted for 88% of cases with five Girdlestone procedures being performed and 12 requiring soft-tissue flap reconstruction. Mean operative time was 3.8hours. Four patients required high-dependency care and 13 patients received long-term antibiotics. Only three minor complications (20%) were seen with postoperative wound dehiscence. DISCUSSION The multidisciplinary team clinic allows careful assessment and selection of patients appropriate for surgical reconstruction and to help match expectations and limitations imposed by surgery, which are likely to influence their current lifestyle in this largely independent patient group. Collaboration with other specialties gives the best surgical outcome both for the present episode as well as leaving avenues open for potential future reconstruction.

Abstract A48: The lncRNA HOTAIR is overexpressed in Ewing sarcoma and promotes malignant transformation through interactions with histone-modifying complexes

Introduction: Ewing sarcoma (ES) is an aggressive primitive cancer of the bone and soft tissue in adolescents and young adults, typified by chromosomal translocations resulting in fusions of the EWS gene and an ETS family gene, most commonly FLI1. The resulting EWS-FLI1 fusion protein is the oncogenic driver in this cancer, but its expression alone does not induce malignant transformation in human mesenchymal stem cells (hMSCs), the putative cell of origin. Instead, EWS-FLI1 induces apoptosis in most recipient cell line and animal models. The lncRNA HOTAIR is upregulated in multiple types of cancer and promote tumorigenesis. However, its expression and function have not been studied in Ewing sarcoma.

Methods: We used the R2 (http://r2.amc.nl) and Oncogenomics (https://pob.abcc.ncifcrf.gov/cgi-bin/JK) platforms to examine the expression of HOTAIR in Ewing sarcomas as compared to other tumors and normal tissues, as assessed in high-throughput datasets. We directly measured HOTAIR expression by RT-qPCR on total RNA from ES cell lines (n=13), primary marrow-derived hMSCs (n=2), and primary ES tumors (n=22). We repressed HOTAIR expression in cell lines by shRNA and antisense locked nucleic acid GAPmers (Exiqon), and we overexpressed HOTAIR by plasmid transfection into hMSCs. We then evaluated the phenotype of HOTAIR in these models. We performed RNA immunoprecipitation (RIP) on parental cell line extracts to identify interacting proteins with HOTAIR. We transfected mutant forms of HOTAIR into hMSCs and evaluated the effect of loss of interaction with partner proteins on the HOTAIR phenotype. We co-transfected EWS-FLI1 and HOTAIR into hMSCs to evaluate viability and phenotype.

Results: HOTAIR was found to be most highly expressed in 3 independent datasets of primary Ewing sarcomas on the R2 platform as compared to all other primary tumors. In one dataset, HOTAIR was overexpressed in Ewing sarcomas (n=68) as compared to normal tissues (n=18, p&lt;0.0001). In the Oncogenomics platform, HOTAIR was overexpressed in all ES cell lines (n=50) and primary tumors (n=72). By RT-qPCR, HOTAIR was overexpressed in 11/13 ES cell lines and 17/22 primary tumors as compared to primary hMSCs.

We reduced HOTAIR expression in three ES cell lines by shRNA. We saw no effects on proliferation or chemosensitivity. However, cells with reduced HOTAIR expression had a significant reduction in anchorage-independent tumorsphere formation in soft agar, as compared to nonsilencing control cells (p≤0.01 across all three cell lines). Overexpression of HOTAIR in hMSCs this allowed anchorage independent colony formation in these cells, a phenotype not observed in the parental or vector-control cells. Treatment of the ES cell lines or HOTAIR-overexpressing hMSCs with HOTAIR-specific antisense GAPmers abrogated tumorsphere formation.

We confirmed by RIP that, in ES cell lines, HOTAIR interacts with the histone-modifying proteins EZH2 at its 5' domain and LSD1 at its 3' domain, and deletion of each domain disrupts the interaction with each protein specifically. Transfection of hMSCs with HOTAIR mutants lacking either the 5' or 3' domains also failed to allow anchorage-independent tumorsphere formation. Finally, co-transfection of full-length HOTAIR with EWS-FLI1 into hMSCs allowed cell viability and tumorsphere formation, whereas expression of EWS-FLI1 alone or with mutant HOTAIR did not.

Conclusions: The lncRNA HOTAIR is significantly overexpressed in Ewing sarcoma and promotes malignant transformation and tumorigenesis through mechanisms dependent on interaction with the histone-modifying proteins EZH2 and LSD1. HOTAIR may promote survival in EWS-FLI1 mediated transformation, and it may be a potential therapeutic target given its high expression in tumors and low expression in most normal tissues.

Citation Format: Hasan Siddiqui, Julia Selich-Taylor, Joshua Felgenhauer, Satoru Otsuru, Edwin Horwitz, Nilay Shah. The lncRNA HOTAIR is overexpressed in Ewing sarcoma and promotes malignant transformation through interactions with histone-modifying complexes. [abstract]. In: Proceedings of the AACR Special Conference on Noncoding RNAs and Cancer: Mechanisms to Medicines ; 2015 Dec 4-7; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2016;76(6 Suppl):Abstract nr A48.

Improving outcomes following reconstruction of pressure sores in spinal injury patients: A multidisciplinary approach

BACKGROUND AND AIM

Pressure sore treatment in spinal injury patients is challenging. A multidisciplinary approach with joint management by the plastic surgery and spinal injury teams was initiated at our institution in 2005 to improve patient care and surgical outcomes following reconstruction. This study assessed the surgical outcomes following reconstruction using the team approach and to compare inpatient stay and readmissions for complications before and after the multidisciplinary protocol was introduced.

METHODS

A retrospective review of consecutive patients in the multidisciplinary pressure sore clinic was performed. Data were collected on patient demographics, reconstructive techniques, surgical outcomes and readmission for any complications.

RESULTS

In total, 45 patients with 60 pressure sores (grade 3 or 4) were reviewed in the joint clinic between 2005 and 2011. The majority of patients were paraplegic (78%), while the remaining 22% were tetraplegic. Ischial sores were the most common (45%) followed by trochanteric (23%) and sacral (20%) sores. Multiple sores were noted in 44% of patients. Flap reconstruction was required in 32 patients (71%); after a mean follow-up time of 33 months (range 25-72 months), there were three (9%) major complications (two recurrences of pressure sores and one sinus) and seven (22%) minor complications. After introduction of patient care pathways through the multidisciplinary approach, the rate of readmission for complications decreased from 14% to 5.5% and inpatient stay upon readmission reduced from 65 to 45 days.

CONCLUSIONS

Implementation of a multidisciplinary approach was key to optimising surgical outcomes, achieving a low recurrence rate (6%) and reducing readmissions.

PBX1 is a favorable prognostic biomarker as it modulates 13-cis retinoic acid-mediated differentiation in neuroblastoma

PURPOSE

Neuroblastoma is an embryonic childhood cancer with high mortality. 13-cis retinoic acid (13-cisRA) improves survival for some patients, but many recur, suggesting clinical resistance. The mechanism of resistance and the normal differentiation pathway are poorly understood. Three-amino-acid loop extension (TALE) family genes are master regulators of differentiation. Because retinoids promote differentiation in neuroblastoma, we evaluated TALE family gene expression in neuroblastoma.

EXPERIMENTAL DESIGN

We evaluated expression of TALE family genes in RA-sensitive and -resistant neuroblastoma cell lines, with and without 13-cisRA treatment, identifying genes whose expression correlates with retinoid sensitivity. We evaluated the roles of one gene, PBX1, in neuroblastoma cell lines, including proliferation and differentiation. We evaluated PBX1 expression in primary human neuroblastoma samples by qRT-PCR, and three independent clinical cohort microarray datasets.

RESULTS

We confirmed that induction of PBX1 expression, and no other TALE family genes, was associated with 13-cisRA responsiveness in neuroblastoma cell lines. Exogenous PBX1 expression in neuroblastoma cell lines, mimicking induced PBX1 expression, significantly impaired proliferation and anchorage-independent growth, and promoted RA-dependent and -independent differentiation. Reduced PBX1 protein levels produced an aggressive growth phenotype and RA resistance. PBX1 expression correlated with histologic neuroblastoma subtypes, with highest expression in benign ganglioneuromas and lowest in high-risk neuroblastomas. High PBX1 expression is prognostic of survival, including in multivariate analysis, in the three clinical cohorts.

CONCLUSIONS

PBX1 is an essential regulator of differentiation in neuroblastoma and potentiates retinoid-induced differentiation. Neuroblastoma cells and tumors with low PBX1 expression have an immature phenotype with poorer prognosis, independent of other risk factors.

A kick in the shins: the financial impact of uncontrolled warfarin use in pre-tibial haematomas

Warfarin is increasingly prescribed in the elderly population for a number of medical conditions. Pre-tibial haematomas are a common cause of morbidity in this group. The aim of the study was to identify the proficiency of INR monitoring at a primary care level in correlation with their recommended INR range and to study the treatment outcome in this group. A retrospective single-centre study of patients diagnosed with pre-tibial haematomas was conducted over a two-year period. Length of hospital stay, time delay until operative intervention, blood transfusion and warfarin reversal requirements, social care input and cost to the NHS were considered. A total of 62 patients were admitted with pre-tibial haematomas of which 20 were on Warfarin. Females were predominantly more affected (5.6:1). The mechanism of injury was as a result of minor trauma. The mean INR level was 3.8 with a standard deviation of 3.1. Mean length of hospital stay was 11 days with a standard deviation of 13.6. Nine patients required skin grafting. Average cost for the acute episode was £3500 per patient. INR levels were significantly outwith the target range causing substantial patient morbidity and imposing a significant financial burden on the NHS. Tighter regulation at a primary care level should help reduce this risk.

The surgical treatment of Balanitis Xerotica Obliterans

BACKGROUND

Balanitis Xerotica Obliterans (BXO) is a chronic, often progressive disease, which can lead to phimosis and urethral stenosis, affecting both urinary and sexual function. Steroid creams are usually the first-line treatment but have a limited role and surgical intervention is frequently necessary. Conservative surgical procedures (circumcision) are often preferred in the first instance with the premise that recurrence of disease will require a more definitive reconstruction. This study looked at patients with pathologically proven BXO referred to the Plastic Surgery Unit at James Cook University Hospital between 2005 and 2009. The aim was to look at their management in the past and subsequent management by us. We also looked at whether early referral of progressive and recurrent BXO patients to reconstructive surgery could have prevented unnecessary delay in resolving symptoms at an earlier stage.

MATERIALS AND METHODS

Data was collected retrospectively and information regarding the exact anatomical location affected, the extent of the disease, the referring specialty and any previous surgical interventions was obtained. Alterations in urinary and sexual function and relief of symptoms following reconstructive surgery were analysed.

RESULTS

Of the 23 patients in the study, 43% had previous surgery and 60% of those had undergone two or more procedures. Twenty-one percent of patients had a history of BXO for over five years. Forty-seven percent of patients had alteration in their urinary function and 48% alteration in their sexual function due to the disease, prior to referral. Early results showed remarkable improvement in urinary and sexual function following reconstructive surgery in this group.

CONCLUSIONS

Steroid creams have been shown to limit the progression of the disease but do not offer a cure in the majority of cases. Circumcision can be a curative procedure in early disease. Although there is conflicting evidence for treatment of recurring urethral strictures, repeated urethrotomy or urethral dilatation has poor long-term outcome. In patients with recurrent disease and associated complications we propose early referral to a plastic surgeon with genitourinary interest or reconstructive urologist for definitive treatment.

SWI/SNF deficiency results in aberrant chromatin organization, mitotic failure, and diminished proliferative capacity

Switch (SWI)/sucrose nonfermentable (SNF) is an evolutionarily conserved complex with ATPase function, capable of regulating nucleosome position to alter transcriptional programs within the cell. It is known that the SWI/SNF complex is responsible for regulation of many genes involved in cell cycle control and proliferation, and it has recently been implicated in cancer development. The ATPase action of SWI/SNF is conferred through either the brahma-related gene 1 (Brg1) or brahma (Brm) subunit of the complex, and it is of central importance to the modification of nucleosome position. In this study, the role of the Brg1 and Brm subunits were examined as they relate to chromatin structure and organization. Deletion of the Brg1 ATPase results in dissolution of pericentromeric heterochromatin domains and a redistribution of histone modifications associated with these structures. This effect was highly specific to Brg1 and is not reproduced by the loss of Brm or SNF5/BAF47/INI1. Brg1 deficiency is associated with the appearance of micronuclei and aberrant mitoses that are a by-product of dissociated chromatin structure. Thus, Brg1 plays a critical role in maintaining chromatin structural integrity.

Prevalence and correlates of HIV, syphilis, and hepatitis knowledge among intrapartum patients and health care providers in Kabul, Afghanistan

Little is known about blood-borne infection awareness and knowledge among obstetric populations and health care providers in Afghanistan. HIV and hepatitis B awareness and knowledge are described among 4452 intrapartum patients completing an interviewer-administered questionnaire and whole-blood rapid testing and 123 obstetric care providers completing a questionnaire between June 2006 and September 2006. Participants were enrolled from three Kabul public maternity hospitals. Most participants were aware of HIV (50.8% of patients and 95.9% of providers) and hepatitis (72.1% of patients and 91.1% of providers). Correct transmission knowledge (defined as naming three correct routes and no incorrect routes) was lower for both groups (HIV: 19.4% for patients and 59.7% for providers; hepatitis B: 1.90% for patients and 33.9% for providers). Correct HIV transmission knowledge among providers was independently associated with level of education (AOR=1.75, 95% CI: 1.20-2.55). While HIV and hepatitis B awareness is common, correct and comprehensive knowledge is not. Continuing education for providers and health communications strategies should address identified knowledge gaps.

Targeted ablation of the WW domain-containing oxidoreductase tumor suppressor leads to impaired steroidogenesis

The WW domain-containing oxidoreductase (WWOX) gene encodes a 46-kDa tumor suppressor. The Wwox protein contains two N-terminal WW domains that interact with several transcriptional activators containing proline-tyrosine motifs and a central short-chain dehydrogenase/reductase domain that has been suggested to play a role in steroid metabolism. Recently, we have shown that targeted deletion of the Wwox gene in mice leads to postnatal lethality and defects in bone growth. Here, we report that Wwox-deficient mice display impaired steroidogenesis. Mutant homozygous mice are born with gonadal abnormalities, including failure of Leydig cell development in testis and reduced theca cell proliferation in ovary. Furthermore, Wwox(-/-) mice displayed impaired gene expression of key steroidogenesis enzymes. Affymetrix microarray gene analysis revealed differentially expressed related genes in steroidogenesis in knockout mice testis and ovary as compared with control mice. These results demonstrate the essential requirement for the Wwox tumor suppressor in proper steroidogenesis.

Synergistic function of E2F7 and E2F8 is essential for cell survival and embryonic development

The E2f7 and E2f8 family members are thought to function as transcriptional repressors important for the control of cell proliferation. Here, we have analyzed the consequences of inactivating E2f7 and E2f8 in mice and show that their individual loss had no significant effect on development. Their combined ablation, however, resulted in massive apoptosis and dilation of blood vessels, culminating in lethality by embryonic day E11.5. A deficiency in E2f7 and E2f8 led to an increase in E2f1 and p53, as well as in many stress-related genes. Homo- and heterodimers of E2F7 and E2F8 were found on target promoters, including E2f1. Importantly, loss of either E2f1 or p53 suppressed the massive apoptosis in double-mutant embryos. These results identify E2F7 and E2F8 as a unique repressive arm of the E2F transcriptional network that is critical for embryonic development and control of the E2F1-p53 apoptotic axis.

SWI/SNF activity is required for the repression of deoxyribonucleotide triphosphate metabolic enzymes via the recruitment of mSin3B

The SWI/SNF chromatin remodeling complex plays a critical role in the coordination of gene expression with physiological stimuli. The synthetic enzymes ribonucleotide reductase, dihydrofolate reductase, and thymidylate synthase are coordinately regulated to ensure appropriate deoxyribonucleotide triphosphate levels. Particularly, these enzymes are actively repressed as cells exit the cell cycle through the action of E2F transcription factors and the retinoblastoma tumor suppressor/p107/p130 family of pocket proteins. This process is found to be highly dependent on SWI/SNF activity as cells deficient in BRG-1 and Brm subunits fail to repress these genes with activation of pocket proteins, and this deficit in repression can be complemented, via the ectopic expression of BRG-1. The failure to repress transcription does not involve a blockade in the association of E2F or pocket proteins p107 and p130 with promoter elements. Rather, the deficit in repression is due to a failure to mediate histone deacetylation of ribonucleotide reductase, dihydrofolate reductase, and thymidylate synthase promoters in the absence of SWI/SNF activity. The basis for this is found to be a failure to recruit mSin3B and histone deacetylase proteins to promoters. Thus, the coordinate repression of deoxyribonucleotide triphosphate metabolic enzymes is dependent on the action of SWI/SNF in facilitating the assembly of repressor complexes at the promoter.

Loss of RB compromises specific heterochromatin modifications and modulates HP1alpha dynamics

Heterochromatin domains are important for gene silencing, centromere organization, and genomic stability. These genomic domains are marked with specific histone modifications, heterochromatin protein 1 (HP1) binding and DNA methylation. The retinoblastoma tumor suppressor, RB mediates transcriptional repression and functionally interacts with a number of factors that are involved in heterochromatin biology including HP1, Suv39h1, DNMT1, and components of the SWI/SNF chromatin remodeling complex. To analyze the specific influence of RB loss on chromatin modification, mouse adult fibroblasts (MAFs) derived from Rb(loxP/loxP) mice were utilized to acutely knockout RB. In this setting, target genes of RB are deregulated. Additionally, changes in histone modifications were observed. Specifically, histone H4 lysine 20 trimethylation was absent from heterochromatin domains following loss of RB and there were changes in the relative levels of histone modifications between RB-proficient and deficient cells. While RB loss significantly altered the modifications associated with heterochromatin domains, these domains were readily identified and efficiently mediated the recruitment of HP1alpha. Kinetic analyses of HP1alpha within the heterochromatin domains present in RB-deficient cells indicated that loss of RB retarded HP1alpha dynamics, indicating that HP1alpha is paradoxically more tightly associated with heterochromatin in the absence of RB function. Combined, these analyses demonstrate that loss of RB has global effects on chromatin modifications and dynamics.

Hierarchical requirement of SWI/SNF in retinoblastoma tumor suppressor-mediated repression of Plk1

Plk1 (Polo-like kinase 1) is a critical regulator of cell cycle progression that harbors oncogenic activity and exhibits aberrant expression in multiple tumors. However, the mechanism through which Plk1 expression is regulated has not been extensively studied. Here we demonstrate that Plk1 is a target of the retinoblastoma tumor suppressor (RB) pathway. Activation of RB and related pocket proteins p107/p130 mediate attenuation of Plk1. Conversely, RB loss deregulates the control of Plk1 expression. RB pathway activation resulted in the repression of Plk1 promoter activity, and this action was dependent on the SWI/SNF chromatin remodeling complex. Although SWI/SNF subunits are lost during tumorigenesis and cooperate with RB for transcriptional repression, the mechanism through which SWI/SNF impinges on RB action is unresolved. Therefore, we delineated the requirement of SWI/SNF for three critical facets of Plk1 promoter regulation: transcription factor binding, corepressor binding, and histone modification. We find that E2F4 and pocket protein association with the Plk1 promoter is independent of SWI/SNF. However, these analyses revealed that SWI/SNF is required for histone deacetylation of the Plk1 promoter. The importance of SWI/SNF-dependent histone deacetylation of the Plk1 promoter was evident, because blockade of this event restored Plk1 expression in the presence of active RB. In summary, these data demonstrate that Plk1 is a target of the RB pathway. Moreover, these findings demonstrate a hierarchical role for SWI/SNF in the control of promoter activity through histone modification.

Geminin is targeted for repression by the retinoblastoma tumor suppressor pathway through intragenic E2F sites

The geminin protein is a critical regulator of DNA replication. It functions to control replication fidelity by blocking the assembly of prereplication complexes in the S and G(2) phases of the cell cycle. Geminin protein levels, which are low in G(0)/G(1) and increase at the G(1)/S transition, are controlled through coordinate transcriptional and proteolytic regulation. Here we show that geminin is regulated transcriptionally by the retinoblastoma tumor suppressor (RB)/E2F pathway. Initially, we observed that the activation of RB led to the repression of geminin transcription. Conversely, Rb-null mouse embryonic fibroblasts have enhanced the expression of geminin relative to wild type mouse embryonic fibroblasts. Similarly, an acute loss of Rb in mouse adult fibroblasts deregulated geminin RNA and protein levels. To delineate the responsible regulatory motifs, luciferase reporter constructs containing fragments of the geminin promoter were generated. An analysis of the critical regulatory cis-acting elements in the geminin promoter indicated that intragenic E2F sites down-stream of the first exon were responsible for RB-mediated repression of geminin. The direct analysis of the endogenous geminin promoter revealed that these intragenic E2F sites are occupied by E2F proteins, and the mutation of these sites eliminates responsiveness to RB. Together, these data link the expression of geminin to the RB/E2F pathway and represent the first promoter analysis of this important regulator of DNA replication.

Histone deacetylation of RB-responsive promoters: requisite for specific gene repression but dispensable for cell cycle inhibition

The retinoblastoma tumor suppressor protein (RB) is targeted for inactivation in the majority of human tumors, underscoring its critical role in attenuating cellular proliferation. RB inhibits proliferation by repressing the transcription of genes that are essential for cell cycle progression. To repress transcription, RB assembles multiprotein complexes containing chromatin-modifying enzymes, including histone deacetylases (HDACs). However, the extent to which HDACs participate in transcriptional repression and are required for RB-mediated repression has not been established. Here, we investigated the role of HDACs in RB-dependent cell cycle inhibition and transcriptional repression. We find that active RB mediates histone deacetylation on cyclin A, Cdc2, topoisomerase IIalpha, and thymidylate synthase promoters. We also demonstrate that this deacetylation is HDAC dependent, since the HDAC inhibitor trichostatin A (TSA) prevented histone deacetylation at each promoter. However, TSA treatment blocked RB repression of only a specific subset of genes, thereby demonstrating that the requirement of HDACs for RB-mediated transcriptional repression is promoter specific. The HDAC-independent repression was not associated with DNA methylation or gene silencing but was readily reversible. We show that this form of repression resulted in altered chromatin structure and was dependent on SWI/SNF chromatin remodeling activity. Importantly, we find that cell cycle inhibitory action of RB is not intrinsically dependent on the ability to recruit HDAC activity. Thus, while HDACs do play a major role in RB-mediated repression, they are dispensable for the repression of critical targets leading to cell cycle arrest.

Utilising field assignments in survey methodology course at Ziauddin Medical University, Karachi

OBJECTIVE

To describe the teaching-learning strategy employed in the module of Survey Methodology for undergraduate medical students at Ziauddin Medical University.

SETTING

Medical students of Ziauddin Medical University, Clifton, Karachi.

METHODS

The objectives of the Survey Methodology course were developed so that a student would be able to design and conduct a small survey independently. For this purpose the students were required to participate in a census survey of a squatter settlement. The questionnaire for the survey was developed with the students, which included the demographic information of the households. It was discussed and pretested with the medical students. The students edited and entered the data on computer using Epi-Info. They were trained in sampling methods, data collection, data editing and entry through lectures and small group sessions. At the end of the course, students filled the course evaluation form.

RESULTS

Out of 117 students who responded, 63% found the course to be useful. Small group sessions were regarded as the most helpful teaching strategy by 91% of the students. Majority (74%) of the students recommended that field visits should be a part of teaching strategy.

CONCLUSION

The Survey Methodology course reinforces the importance and practical application of research methods. The students appreciate the course especially the small group sessions and the field visits.

Cannula related suppurative thrombophlebitis in the burned patient

Suppurative thrombophlebitis is a well recognised and potentially fatal complication of intravenous cannulation in burns patients. We report a case of an Afro-Caribbean patient with noninsulin-dependent diabetes who developed signs of systemic sepsis two weeks after a 14% total body surface area flame burn. Despite an initial paucity of clinical signs at the cannulation site, exploratory venotomy revealed frank suppuration within the long saphenous vein from the ankle to the groin. This was treated successfully by total excision of the vein and its tributaries and delayed wound closure. Following this, a retrospective analysis of the measured clinical parameters and blood tests revealed no obvious, missed pointers to the impending sepsis other than a dramatic increase in the overall daily insulin requirement. This had doubled over a 48-h period, preceding the clinical diagnosis by three days. The relevant literature and guidelines for management are reviewed.

Systemic lupus erythematosus in Kuwait--hospital based study

The present study describes the clinical characteristics of patients with systemic lupus erythematosus (SLE), from the rheumatology service of the two main teaching hospitals in Kuwait. It was a retrospective-cum-prospective clinical study of 108 SLE patients. There were 98 females and 10 males, with a median age of 31.5y. Kuwaitis constituted 69%, while 31% were expatriates. The mean disease duration was 62 months. The main clinical features were: musculoskeletal involvement (87%), photosensitivity (48%), malar rash (43%), discoid lesions (10%), oral ulcers (33%), vasculitic skin lesions (10%), haematological features (53%), constitutional symptoms (51.4%), neuropsychiatric manifestations (23%), renal involvement (37%), serositis (29%), clinical manifestations of antiphospholipid syndrome (21%), cardiac involvement (10%) and pulmonary manifestations (19%). In conclusion, the clinical features of SLE in Kuwait were similar to most major studies from developed countries. Main differences included prominent haematological and mucocutaneous manifestations and possibly a low prevalence of anti-Sm antibodies. Whether these differences are due to the environment or genetic factors, remains to be studied.

Further observations concerning steroidal, β-lactones. Boron trifluoride catalysed rearrangements of β-lactones in the cholestane series

B-Nor-5β-cholestane-3,3,5-diol-6-carboxylic acid 5,6-lactone 3-acetate on treatment with BF3 etherate in ether or ether-acetic anhydride gave B-norcholest-5-en-3β-ol-6-carboxylic acid 3-acetate and 19-nor-5-methyl-B-nor-5β-cholest-9(10)-en-3,3-ol-6-carboxylic acid 3-acetate, a product of the Westphalen rearrangement. B-Nor-5β-cholestan-5-ol-6-carboxylic acid 5,6-lactone under similar reaction conditions provided the product of the Westphalen rearrangement, 19-nor-5-methyl-B-nor-5β-cholest-9(10)-ene-6-carboxylic acid.