Protracted neuronal recruitment in the temporal lobes of young children

The temporal lobe of the human brain contains the entorhinal cortex (EC). This region of the brain is a highly interconnected integrative hub for sensory and spatial information; it also has a key role in episodic memory formation and is the main source of cortical hippocampal inputs1-4. The human EC continues to develop during childhood5, but neurogenesis and neuronal migration to the EC are widely considered to be complete by birth. Here we show that the human temporal lobe contains many young neurons migrating into the postnatal EC and adjacent regions, with a large tangential stream persisting until the age of around one year and radial dispersal continuing until around two to three years of age. By contrast, we found no equivalent postnatal migration in rhesus macaques (Macaca mulatta). Immunostaining and single-nucleus RNA sequencing of ganglionic eminence germinal zones, the EC stream and the postnatal EC revealed that most migrating cells in the EC stream are derived from the caudal ganglionic eminence and become LAMP5+RELN+ inhibitory interneurons. These late-arriving interneurons could continue to shape the processing of sensory and spatial information well into postnatal life, when children are actively interacting with their environment. The EC is one of the first regions of the brain to be affected in Alzheimer's disease, and previous work has linked cognitive decline to the loss of LAMP5+RELN+ cells6,7. Our investigation reveals that many of these cells arrive in the EC through a major postnatal migratory stream in early childhood.

A myeloid program associated with COVID-19 severity is decreased by therapeutic blockade of IL-6 signaling

Altered myeloid inflammation and lymphopenia are hallmarks of severe infections. We identified the upregulated EN-RAGE gene program in airway and blood myeloid cells from patients with acute lung injury from SARS-CoV-2 or other causes across 7 cohorts. This program was associated with greater clinical severity and predicted future mechanical ventilation and death. EN-RAGEhi myeloid cells express features consistent with suppressor cell functionality, including low HLA-DR and high PD-L1. Sustained EN-RAGE program expression in airway and blood myeloid cells correlated with clinical severity and increasing expression of T cell dysfunction markers. IL-6 upregulated many EN-RAGE program genes in monocytes in vitro. IL-6 signaling blockade by tocilizumab in a placebo-controlled clinical trial led to rapid normalization of EN-RAGE and T cell gene expression. This identifies IL-6 as a key driver of myeloid dysregulation associated with worse clinical outcomes in COVID-19 patients and provides insights into shared pathophysiological mechanisms in non-COVID-19 ARDS.

Mitigation of chromosome loss in clinical CRISPR-Cas9-engineered T cells

CRISPR-Cas9 genome editing has enabled advanced T cell therapies, but occasional loss of the targeted chromosome remains a safety concern. To investigate whether Cas9-induced chromosome loss is a universal phenomenon and evaluate its clinical significance, we conducted a systematic analysis in primary human T cells. Arrayed and pooled CRISPR screens revealed that chromosome loss was generalizable across the genome and resulted in partial and entire loss of the targeted chromosome, including in preclinical chimeric antigen receptor T cells. T cells with chromosome loss persisted for weeks in culture, implying the potential to interfere with clinical use. A modified cell manufacturing process, employed in our first-in-human clinical trial of Cas9-engineered T cells (NCT03399448), reduced chromosome loss while largely preserving genome editing efficacy. Expression of p53 correlated with protection from chromosome loss observed in this protocol, suggesting both a mechanism and strategy for T cell engineering that mitigates this genotoxicity in the clinic.

Modular pooled discovery of synthetic knockin sequences to program durable cell therapies

Chronic stimulation can cause T cell dysfunction and limit the efficacy of cellular immunotherapies. Improved methods are required to compare large numbers of synthetic knockin (KI) sequences to reprogram cell functions. Here, we developed modular pooled KI screening (ModPoKI), an adaptable platform for modular construction of DNA KI libraries using barcoded multicistronic adaptors. We built two ModPoKI libraries of 100 transcription factors (TFs) and 129 natural and synthetic surface receptors (SRs). Over 30 ModPoKI screens across human TCR- and CAR-T cells in diverse conditions identified a transcription factor AP4 (TFAP4) construct that enhanced fitness of chronically stimulated CAR-T cells and anti-cancer function in vitro and in vivo. ModPoKI's modularity allowed us to generate an ∼10,000-member library of TF combinations. Non-viral KI of a combined BATF-TFAP4 polycistronic construct enhanced fitness. Overexpressed BATF and TFAP4 co-occupy and regulate key gene targets to reprogram T cell function. ModPoKI facilitates the discovery of complex gene constructs to program cellular functions.

Mitigation of chromosome loss in clinical CRISPR-Cas9-engineered T cells

CRISPR-Cas9 genome editing has enabled advanced T cell therapies, but occasional loss of the targeted chromosome remains a safety concern. To investigate whether Cas9-induced chromosome loss is a universal phenomenon and evaluate its clinical significance, we conducted a systematic analysis in primary human T cells. Arrayed and pooled CRISPR screens revealed that chromosome loss was generalizable across the genome and resulted in partial and entire loss of the chromosome, including in pre-clinical chimeric antigen receptor T cells. T cells with chromosome loss persisted for weeks in culture, implying the potential to interfere with clinical use. A modified cell manufacturing process, employed in our first-in-human clinical trial of Cas9-engineered T cells, 1 dramatically reduced chromosome loss while largely preserving genome editing efficacy. Expression of p53 correlated with protection from chromosome loss observed in this protocol, suggesting both a mechanism and strategy for T cell engineering that mitigates this genotoxicity in the clinic.

Single-cell RNA-seq reveals cell type-specific molecular and genetic associations to lupus

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease. Knowledge of circulating immune cell types and states associated with SLE remains incomplete. We profiled more than 1.2 million peripheral blood mononuclear cells (162 cases, 99 controls) with multiplexed single-cell RNA sequencing (mux-seq). Cases exhibited elevated expression of type 1 interferon-stimulated genes (ISGs) in monocytes, reduction of naïve CD4+ T cells that correlated with monocyte ISG expression, and expansion of repertoire-restricted cytotoxic GZMH+ CD8+ T cells. Cell type-specific expression features predicted case-control status and stratified patients into two molecular subtypes. We integrated dense genotyping data to map cell type-specific cis-expression quantitative trait loci and to link SLE-associated variants to cell type-specific expression. These results demonstrate mux-seq as a systematic approach to characterize cellular composition, identify transcriptional signatures, and annotate genetic variants associated with SLE.

CRISPR activation and interference screens decode stimulation responses in primary human T cells

Regulation of cytokine production in stimulated T cells can be disrupted in autoimmunity, immunodeficiencies, and cancer. Systematic discovery of stimulation-dependent cytokine regulators requires both loss-of-function and gain-of-function studies, which have been challenging in primary human cells. We now report genome-wide CRISPR activation (CRISPRa) and interference (CRISPRi) screens in primary human T cells to identify gene networks controlling interleukin-2 (IL-2) and interferon-γ (IFN-γ) production. Arrayed CRISPRa confirmed key hits and enabled multiplexed secretome characterization, revealing reshaped cytokine responses. Coupling CRISPRa screening with single-cell RNA sequencing enabled deep molecular characterization of screen hits, revealing how perturbations tuned T cell activation and promoted cell states characterized by distinct cytokine expression profiles. These screens reveal genes that reprogram critical immune cell functions, which could inform the design of immunotherapies.

Type I interferon autoantibodies are associated with systemic immune alterations in patients with COVID-19

A subset of patients diagnosed with coronavirus disease 2019 (COVID-19) present with autoantibodies specific to type I interferons (IFNs). However, the systemic impacts of type I IFN–specific autoantibodies are not fully understood. Here, van der Wijst et al. longitudinally evaluated the relationship between type I IFN–specific autoantibody abundance and changes to the immune system of individuals with COVID-19. Using single-cell transcriptomics, the authors found that the presence of type I IFN autoantibodies correlated with reduced type I IFN–stimulated gene (ISG) expression in patients with critical COVID-19. Reduced ISG expression, in turn, correlated with increased expression of the inhibitory receptor, leukocyte-associated immunoglobulin-like receptor 1 (LAIR1), on monocytes. Together, these findings suggest that early evidence of type I IFN autoantibodies and increased LAIR1 expression may help distinguish severe cases of COVID-19.

Neutralizing autoantibodies against type I interferons (IFNs) have been found in some patients with critical coronavirus disease 2019 (COVID-19), the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the prevalence of these antibodies, their longitudinal dynamics across the disease severity scale, and their functional effects on circulating leukocytes remain unknown. Here, in 284 patients with COVID-19, we found type I IFN–specific autoantibodies in peripheral blood samples from 19% of patients with critical disease and 6% of patients with severe disease. We found no type I IFN autoantibodies in individuals with moderate disease. Longitudinal profiling of over 600,000 peripheral blood mononuclear cells using multiplexed single-cell epitope and transcriptome sequencing from 54 patients with COVID-19 and 26 non–COVID-19 controls revealed a lack of type I IFN–stimulated gene (ISG-I) responses in myeloid cells from patients with critical disease. This was especially evident in dendritic cell populations isolated from patients with critical disease producing type I IFN–specific autoantibodies. Moreover, we found elevated expression of the inhibitory receptor leukocyte-associated immunoglobulin-like receptor 1 (LAIR1) on the surface of monocytes isolated from patients with critical disease early in the disease course. LAIR1 expression is inversely correlated with ISG-I expression response in patients with COVID-19 but is not expressed in healthy controls. The deficient ISG-I response observed in patients with critical COVID-19 with and without type I IFN–specific autoantibodies supports a unifying model for disease pathogenesis involving ISG-I suppression through convergent mechanisms.

Determination of the membrane topology of PORCN, an O-acyl transferase that modifies Wnt signalling proteins

Wnt gradients elicit distinct cellular responses, such as proliferation, specification, differentiation and survival in a dose-dependent manner. Porcupine (PORCN), a membrane-bound O-acyl transferase (MBOAT) that resides in the endoplasmic reticulum, catalyses the addition of monounsaturated palmitate to Wnt proteins and is required for Wnt gradient formation and signalling. In humans, PORCN mutations are causal for focal dermal hypoplasia (FDH), an X-linked dominant syndrome characterized by defects in mesodermal and endodermal tissues. PORCN is also an emerging target for cancer therapeutics. Despite the importance of this enzyme, its structure remains poorly understood. Recently, the crystal structure of DltB, an MBOAT family member from bacteria, was solved. In this report, we use experimental data along with homology modelling to DltB to determine the membrane topology of PORCN. Our studies reveal that PORCN has 11 membrane domains, comprising nine transmembrane spanning domains and two reentrant domains. The N-terminus is oriented towards the lumen while the C-terminus is oriented towards the cytosol. Like DltB, PORCN has a funnel-like structure that is encapsulated by multiple membrane-spanning helices. This new model for PORCN topology allows us to map residues that are important for biological activity (and implicated in FDH) onto its three-dimensional structure.

Longitudinal single-cell epitope and RNA-sequencing reveals the immunological impact of type 1 interferon autoantibodies in critical COVID-19: Anti-IFN antibodies in critical COVID-19 correlate with poor ISG response and upregulation of LAIR1 surface protein in PBMCs

Type I interferon (IFN-I) neutralizing autoantibodies have been found in some critical COVID-19 patients; however, their prevalence and longitudinal dynamics across the disease severity scale, and functional effects on circulating leukocytes remain unknown. Here, in 284 COVID-19 patients, we found IFN-I autoantibodies in 19% of critical, 6% of severe and none of the moderate cases. Longitudinal profiling of over 600,000 peripheral blood mononuclear cells using multiplexed single-cell epitope and transcriptome sequencing from 54 COVID-19 patients, 15 non-COVID-19 patients and 11 non-hospitalized healthy controls, revealed a lack of IFN-I stimulated gene (ISG-I) response in myeloid cells from critical cases, including those producing anti-IFN-I autoantibodies. Moreover, surface protein analysis showed an inverse correlation of the inhibitory receptor LAIR-1 with ISG-I expression response early in the disease course. This aberrant ISG-I response in critical patients with and without IFN-I autoantibodies, supports a unifying model for disease pathogenesis involving ISG-I suppression via convergent mechanisms.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

TRIENNIAL GROWTH AND DEVELOPMENT SYMPOSIUM: Dedifferentiated fat cells: Potential and perspectives for their use in clinical and animal science purpose

An increasing body of evidences has demonstrated the ability of the mature adipocyte to dedifferentiate into a population of proliferative-competent cells known as dedifferentiated fat (DFAT) cells. As early as the 1970s, in vitro studies showed that DFAT cells may be obtained by ceiling culture, which takes advantage of the buoyancy property of lipid-filled cells. It was documented that DFAT cells may acquire a phenotype similar to mesenchymal stem cells and yet may differentiate into multiple cell lineages, such as skeletal and smooth muscle cells, cardiomyocytes, osteoblasts, and adipocytes. Additionally, recent studies showed the ability of isolated mature adipocytes to dedifferentiate in vivo and the capacity of the progeny cells to redifferentiate into mature adipocytes, contributing to the increase of body fatness. These findings shed light on the potential for use of DFAT cells, not only for clinical purposes but also within the animal science field, because increasing intramuscular fat without excessive increase in other fat depots is a challenge in livestock production. Knowledge of the mechanisms underlying the dedifferentiation and redifferentiation of DFAT cells will allow the development of strategies for their use for clinical and animal science purposes. In this review, we highlight several aspects of DFAT cells, their potential for clinical purposes, and their contribution to adipose tissue mass in livestock.

Changes in gene expression variability reveal a stable synthetic lethal interaction network in BRCA2-ovarian cancers

Synthetic lethal interactions (SLIs) are robust mechanisms that provide cells with the ability to remain viable despite having mutations in genes critical to the DNA damage response, a core cellular process. Studies in model organisms such as S. cerevisiae showed that thousands of genes important in maintaining DNA integrity cooperated in a SLI network. Two genes participate in a SLI when a mutation in one gene has no effect on the cell, but mutations in both interacting genes are lethal. Furthermore in C. elegans, a mutation in a critical gene that is important for development induced a change in expression variability in the synthetic lethal interactor. In cancer, targeting SLIs shows promise in selectively killing cancer cells. For example, targeting PARP1 is an effective treatment for BRCA1/2- breast and ovarian cancers. Although PARP1 is already identified as having a SLI with BRCA1/2-, computationally searching for other genes that cooperate in the SLI network could highlight genes that may have promise for being a cancer-specific drug target. Using RNA sequencing data for ovarian cancer patients with BRCA2 mutations and the R Bioconductor package pathVar, we showed that genes whose expression changes to an invariant, stable expression state are likely candidates for SLIs with BRCA2. Our results highlight the interactions between the genes with predicted SLIs and protein-coding genes that are functionally important in the DNA damage response. The method of analyzing expression variability to computationally identify genes with SLIs can be applied to query SLIs in other tumor types.

A retrospective comparison of neoadjuvant chemoradiotherapy regimens for locally advanced esophageal cancer

Preoperative chemoradiotherapy (CRT) with carboplatin/paclitaxel has been shown to increase survival in patients with esophageal cancer, including gastroesophageal junction (GE) junction cancer, over surgery alone; however, there have been no studies comparing the different neoadjuvant CRT regimens. We retrospectively evaluated the long-term results of trimodality therapy for patients with locally advanced esophageal cancer treated on several chemotherapy regimens. Between 1999 and 2014, 215 patients with locally advanced esophageal cancer underwent neoadjuvant CRT followed by surgical resection. The median age was 62 years (range 21-84), 80.5% were men and 86% had adenocarcinoma. The following chemotherapy regimens were administered: cisplatin/5FU (14.9%), cisplatin/irinotecan (35.8%), carboplatin/paclitaxel (35.8%), and other (9.7%). The majority of patients (92.1%) received a radiation dose of 50.4 Gy. Predictors of toxicities and surgical complications were assessed using logistic regression. Overall survival (OS) and recurrence-free survival (RFS) were estimated using the Kaplan-Meier method and proportional hazards regression was used to model time-to-event outcomes. The median follow-up among surviving patients was 4.1 years (range 0.4,13). The median OS was 3.0 years from time of diagnosis and OS was 36.8% at 5 years. RFS was 34.9% at 5 years. After neoadjuvant CRT, 34.7% of patients achieved a pathologic complete response including 60.7% of squamous cell carcinoma patients and 18.4% of adenocarcinoma patients (P < 0.001) and 66% were downstaged. Of the variables examined, pathologic stage, preoperative baseline cardiac comorbidity, postoperative cardiac or pulmonary complications, and chemotherapy regimen were associated with OS. Using cisplatin and 5FU as the reference regimen, patients treated with carboplatin/paclitaxel had significantly improved OS (HR = 0.47, P = 0.017 after adjusting for surgery type, radiation modality, baseline cardiac comorbidity, and preoperative stage) with 5-year OS rate of 66%. The most common surgical complications were cardiac in 61 patients (28.5%) and pulmonary in 52 patients (24.3%). Cardiac complications were associated with age (OR 1.05, P = 0.007) and cardiac comorbidity (OR 2.6, P = 0.02) and pulmonary complications with female gender (OR 3.98, P < 0.001). Forty-four patients (20.5%) required readmission within 30 days of discharge, and readmission was associated with cardiac comorbidity (OR 2.7, P = 0.017). Three patients died within 30 days of surgery. We observed an association between neoadjuvant carboplatin/paclitaxel and improved overall survival that requires confirmation in a prospective randomized trial.

A microaliquoting technique for precise histological annotation and optimization of cell content in frozen tissue specimens

Knowledge of the exact cell content of frozen tissue samples is of growing importance in genomic research. We developed a microaliquoting technique to measure and optimize the cell composition of frozen tumor specimens for molecular studies. Frozen samples of 31 mesothelioma cases were cut in alternating thin and thick sections. Thin sections were stained and evaluated visually. Thick sections, i.e., microaliquots, were annotated using bordering stained sections. A range of cellular heterogeneity was observed among and within samples. Precise annotation of samples was obtained by integration and compared to conventional single face and "front and back"’ section estimates of cell content. Front and back estimates were more highly correlated with block annotation by microaliquoting than were single face estimates. Both methods yielded discrepant estimates, however, and for some studies may not adequately account for the heterogeneity of mesothelioma or other malignancies with variable cellular composition. High yield and quality RNA was extracted from precision annotated, tumor-enriched subsamples prepared by combining individual microaliquots with the highest tumor cellularity estimates. Microaliquoting provides accurate cell content annotation and permits genomic analysis of enriched subpopulations of cells without fixation or amplification.

Does BMI predict recurrence or complications after reoperative reflux surgery? Review of a single center's experience and a comparison of outcomes

INTRODUCTION

Obese patients who fail primary surgical management of gastroesophageal reflux present a significant challenge. We reviewed our outcomes with reoperative reflux surgery in obese (body mass index (BMI) >30) and nonobese patients to identify predictors of failure and complications and evaluate whether reoperative fundoplication is the ideal solution for obese patients.

METHODS

We conducted a retrospective review of consecutive patients undergoing reoperation for failed anti-reflux surgery between 1994 and 2013. Medical record review identified preoperative, intraoperative, and postoperative characteristics. Short- and long-term outcomes for obese and nonobese patients were compared using descriptive statistics and logistic regression.

RESULTS

One hundred and nine interventions were identified in 95 patients. Clinical characteristics were similar between obese and nonobese patients. Eighty-eight (83.8%) patients underwent laparoscopic repair, 87 (79.8%) of whom had a Nissen fundoplication. Obese patients were more likely to fail via a slipped wrap (64.7 vs. 40.0%; p = 0.02). No differences were seen in short- or long-term symptomatic relief or major complications. In bivariate analysis, short-term outcomes were predicted by preoperative albumin <3.5 mg/dL (odds ratio (OR), 0.27 (confidence interval (CI), 0.08-0.96); p = 0.04) and laparoscopic conversion (OR, 0.19 (CI, 0.04-1.03); p = 0.05). Laparoscopic conversion was associated with major complications (OR, 7.33 (CI, 1.33-40.55); p = 0.02). BMI was a significant predictor for long-term outcome (p = 0.03) as a continuous variable in sensitivity analyses.

CONCLUSIONS

Obese patients with recurrence after failed anti-reflux operation may be safely treated with a repeat operation. Our data indicate no difference in outcomes for patients with BMI >30, underscoring the importance of preoperative discussion as to the best approach: reoperative fundoplication or a gastric bypass.

Evaluation of two commercial, rapid, ELISA kits testing for scrapie in retro-pharyngeal lymph nodes in sheep

AIMS

To estimate the number of cases of scrapie that would occur in sheep of different prion protein (PrP) genotypes if scrapie was to become established in New Zealand, and to compare the performance of two commercially available, rapid ELISA kits using ovine retro-pharyngeal lymph nodes (RLN) from non-infected and infected sheep of different PrP genotypes.

METHODS

Using published data on the distribution of PrP genotypes within the New Zealand sheep flock and the prevalence of cases of scrapie in these genotypes in the United Kingdom, the annual expected number of cases of scrapie per genotype was estimated, should scrapie become established in New Zealand, assuming a total population of 28 million sheep. A non-infected panel of RLN was collected from 737 sheep from New Zealand that had been culled, found in extremis or died. Brain stem samples were also collected from 131 of these sheep. A second panel of infected samples comprised 218 and 117 RLN from confirmed scrapie cases that had originated in Europe and the United States of America, respectively. All samples were screened using two commercial, rapid, transmissible spongiform encephalopathy ELISA kits: Bio-Rad TeSeE ELISA (ELISA-BR), and IDEXX HerdChek BSE-Scrapie AG Test (ELISA-ID).

RESULTS

If scrapie became established in New Zealand, an estimated 596 cases would occur per year; of these 234 (39%) and 271 (46%) would be in sheep carrying ARQ/ARQ and ARQ/VRQ PrP genotypes, respectively. For the non-infected samples from New Zealand the diagnostic specificity of both ELISA kits was 100%. When considering all infected samples, the diagnostic sensitivity was 70.4 (95% CI=65.3-75.3)% for ELISA-BR and 91.6 (95% CI=88.2-94.4)% for ELISA-ID. For the ARQ/ARQ genotype (n=195), sensitivity was 66.2% for ELISA-BR and 90.8% for ELISA-ID, and for the ARQ/VRQ genotype (n=107), sensitivity was 81.3% for ELISA-BR and 98.1% for ELISA-ID.

CONCLUSIONS

In this study, the ELISA-ID kit demonstrated a higher diagnostic sensitivity for detecting scrapie in samples of RLN from sheep carrying scrapie-susceptible PrP genotypes than the ELISA-BR kit at comparable diagnostic specificity.

CLINICAL RELEVANCE

The diagnostic performance of the ELISA-ID kit using ovine RLN merits the consideration of including this assay in the national scrapie surveillance programme in New Zealand.

New Zealand juvenile oyster mortality associated with ostreid herpesvirus 1-an opportunistic longitudinal study

During the 2010-11 summer outbreak of ostreid herpesvirus 1 (OsHV-1) in New Zealand, an opportunistic longitudinal field study was conducted. OsHV-1 PCR-negative oyster spat (Crassostrea gigas) were relocated to an OsHV-1 PCR-positive area of the North Island of New Zealand that was experiencing juvenile oyster mortalities. Over a period of 13 d, spat were monitored for mortality, sampled for histopathology, and tested for the presence of OsHV-1 using real time PCR and Vibrio culture. Histopathology showed some evidence of tissue pathology; however, no consistent progressive pathology was apparent. Field mortalities were evident from Day 6 on. After 5 and 7 d of exposure, 83 and 100% of spat, respectively, tested positive for the virus by real time PCR. Vibrio species recovered during the longitudinal study included V. splendidus and V. aestuarianus. This study offers insight into the rapidity of onset and virulence of the virus in naïve oyster spat in New Zealand waters.

The effects of six electronic apex locators on pacemaker function: an in vitro study

AIM

To assess the effects of six electronic apex locators (EALs) on pacemaker function in vitro.

METHODOLOGY

Six EALs (Mini Apex Locator®, Dentaport ZX®, Novapex®, Raypex5®, Root ZX mini®, and Justy II®) were tested for electromagnetic interference (EMI) with one pacemaker (Saint Jude Medical). The pacemaker, with a single electrode, was immersed in a saline solution bath adjusted to 400-800 hms to simulate the electrical resistance of the human body and to register the activity by the system. The pacemaker was tested with each of the EALs to analyse the presence of EMI with the EAL switched on, the EAL switched off and during EAL operation. Each series of tests began with a 15-second baseline recording (R0) and continued until all the recording conditions had been covered. The conditions were as follows: R1: recording with the lead of the EAL <2 cm from the tip of the electrode; R2: recording with the lead of the EAL <2 cm from the generator; R3: recording with the lead of the EAL <2 cm from the sensing arc; and R4: recording with the lead of the EAL 15 cm from the sensing arc. If any of the EALs produced interference, its characteristics were categorized.

RESULTS

When the lead of the EAL was <2 cm from the tip of the electrode, the majority of the EALs tested produced only background noise. Only one (the Mini Apex Locator) resulted in EMI that was detected as false heart activity. When the EAL was <2 cm from the generator, just one EAL detected background noise (the Mini Apex Locator). When the EAL was <2 cm from the sensing arc or 15 cm from the sensing arc, the recordings were not affected by any of the EALs. There were no significant differences amongst the EALs analysed with respect to the production of EMI.

CONCLUSIONS

EMI occurred when the EALs were placed close to the tip of the electrode and occasionally when close to the pacemaker; however, no EMI was detected when the EALs were placed near to or 15 cm from the sensing arc in this laboratory experimental model.

Recombinant rubistatin (r-Rub), an MVD disintegrin, inhibits cell migration and proliferation, and is a strong apoptotic inducer of the human melanoma cell line SK-Mel-28

Disintegrins are low molecular weight peptides isolated from viper venom. These peptides bind to integrin receptors using a conserved binding motif sequence containing an RGD or similar motif. As a consequence, disintegrins can inhibit platelet aggregation and inhibit cell migration, proliferation, and initiate apoptosis in cancer cell lines. Rubistatin is a MVD disintegrin cloned from a Crotalus ruber ruber venom gland. The biological activity of MVD disintegrins is poorly understood. Recombinant rubistatin (r-Rub) was cloned into a pET32b plasmid and expressed in reductase-deficient Escherichia coli. Expression was induced with IPTG and the resulting fusion peptide was affinity purified, followed by thrombin cleavage, and removal of vector coded sequences. r-Rub peptide inhibited ADP-induced platelet aggregation by 54% ± 6.38 in whole blood. We assessed the ability of r-Rub to initiate apoptosis in three human cancer cell lines. Cultures of SK-Mel-28, HeLA, and T24 cells were grown for 24 h with 2.5 μM r-Rub followed by Hoechst staining. Chromatin fragmentation was observed in treated SK-Mel-28, but not in T24 or HeLA cells. A TUNEL assay revealed that 51.55% ± 5.28 of SK-Mel-28 cells were apoptotic after 18 h of treatment with 3.5 μM of r-Rub. Cell migration and proliferation assays were performed in order to further characterize the biological effects of r-Rub on SK-Mel-28 cells. At 3 μM, r-Rub inhibited cell migration by 44.4% ± 0.5, while at 3.5 μM it was able to inhibit cell proliferation by 83% ± 6.0.

The Bcl-2 repertoire of mesothelioma spheroids underlies acquired apoptotic multicellular resistance

Three-dimensional (3D) cultures are a valuable platform to study acquired multicellular apoptotic resistance of cancer. We used spheroids of cell lines and actual tumor to study resistance to the proteasome inhibitor bortezomib in mesothelioma, a highly chemoresistant tumor. Spheroids from mesothelioma cell lines acquired resistance to bortezomib by failing to upregulate Noxa, a pro-apoptotic sensitizer BH3-only protein that acts by displacing Bim, a pro-apoptotic Bax/Bak-activator protein. Surprisingly, despite their resistance, spheroids also upregulated Bim and thereby acquired sensitivity to ABT-737, an inhibitor of anti-apoptotic Bcl-2 molecules. Analysis using BH3 profiling confirmed that spheroids acquired a dependence on anti-apoptotic Bcl-2 proteins and were ‘primed for death'. We then studied spheroids grown from actual mesothelioma. ABT-737 was active in spheroids grown from those tumors (5/7, ∼70%) with elevated levels of Bim. Using immunocytochemistry of tissue microarrays of 48 mesotheliomas, we found that most (33, 69%) expressed elevated Bim. In conclusion, mesothelioma cells in 3D alter the expression of Bcl-2 molecules, thereby acquiring both apoptotic resistance and sensitivity to Bcl-2 blockade. Mesothelioma tumors ex vivo also show sensitivity to Bcl-2 blockade that may depend on Bim, which is frequently elevated in mesothelioma. Therefore, mesothelioma, a highly resistant tumor, may have an intrinsic sensitivity to Bcl-2 blockade that can be exploited therapeutically.

The role of extrapleural pneumonectomy in the management of pleural cancers

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Background: We report our experience with EPP for non-mesothelial malignancies. Methods: A retrospective chart review, from June 1994 to October 2007. For all cases, the site of disease involved a single pleura. Results: Sixty-five patients underwent EPP for cancers other than mesothelioma over a 13-year period at our institution. Of these, 32 patients had mediastinoscopy negative T4 lung cancer, 11 had metastases to only one pleura from extrathoracic sites, 10 had unilateral lung sarcomas involving the pleural envelope, 8 had thymomas metastatic to a pleural space, 2 were preoperatively diagnosed as mesotheliomas but at final pathology were determined to be small cell lung cancer and sarcomatoid carcinoma, and 2 represented primary mucoepidermoid and neuroectodermal malignancies. Twenty-eight patients had stage IIIB (T4-N0–1) lung adenocarcinoma representing the largest homogeneous group of patients by cell type and stage. Overall perioperative mortality was 4.6% (3/65). Postoperative morbidity was 44.6% (29/65) with the most common being arrhythmia (n=15), vocal cord paralysis (n=7), and respiratory failure (n=5). Overall survival after surgery was 15.7 months for all the patients. Survival was significantly higher for NSCLC patients with N0 (n=9) on final pathology versus any other nodal status (N1/N2), 52.1 months versus 14.1 months (p=0.0003). Median survival for stage IIIB NSCLC was 16.7 months. Seven of the 8 thymoma patients were alive at last follow-up (median follow-up 22.8 months). Median survival for patients with sarcoma (n=10) or pleural metastases from extrathoracic sites (n=11) was 3.7 and 4.2 months, respectively. Recurrence at follow-up was documented in 21 patients with only 2 (9.5%) occurring in the ipsilateral hemithorax. Conclusions: EPP can be a safe treatment option for some cancers that involve a unilateral pleura. Patients with stage IIIB (T4, N0–1) NSCLC confined to a single pleural cavity or patients with thymoma involving one pleura may benefit from multimodality treatment including EPP. Absence of residual nodal disease at resection is positively correlated with survival in the stage IIIB NSCLC group. Patients undergoing surgical resection for pleural metastases of primary sarcomas or extrathoracic metastasis, however, do not appear to benefit from EPP.

No significant financial relationships to disclose.

Juvenile dogs as potential sentinels for West Nile virus surveillance

We conducted a study to determine whether juvenile stray dogs could be sentinels for West Nile virus (WNV) surveillance. Seroconversion was detected 6 weeks before the first reported human case. Our findings provide evidence that dogs could be useful sentinels for monitoring areas for evidence of WNV during transmission seasons.

Phase I trial of extrapleural pneumonectomy [EPP], and intracavitary intraoperative hyperthermic [IOHC] cisplatin with amifostine cytoprotection for malignant pleural mesothelioma. [MPM]

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Background: Despite aggressive multimodality treatment, MPM remains a disease with poor survival. Innovative strategies that improve cytoreduction are needed. We sought to determine the maximum tolerated dose (MTD) and quantify the toxicity of cisplatin IOHC with amifostine cytoprotection in the setting of EPP for MPM. Methods: 42 MPM patients (pts) were enrolled in an IRB approved protocol. Those who underwent EPP with cytoreduction to < 1 cm3 received 910 mg/m2 of amifostine followed by 1-hour perfusion of the chest and abdomen with cisplatin dose escalation (75–200 mg/m2). Pts were monitored prospectively. Results: 13 pts were unresectable (9 with chest wall invasion, 3 with chest wall and mediastinal invasion and 1 with cardiac invasion). The 29 resected pts had median age 57 years; median stay 15 days, and mortality rate 6.8% (2/29 pts.). Complications were: atrial fibrillation 65.5% (19 pts.), deep vein thrombosis 31% (9 pts.), and grade 3 renal toxicity 31% (9 pts.). Renal toxicity was unrelated to cisplatin dose and no MTD was determined. Median follow-up was 17 months. Median survival (MS) for 42 enrolled pts was 17 months. The 13 unresected pts experienced a 10-month MS. The 29 resected pts had a 20-month MS while 24 epithelial pts experienced a 29-month MS and 5 non-epithelial pts 13 month MS (p=0.006). The 15 pts receiving higher cisplatin doses (175–200 mg/m2) had a 26-month MS while the 14 pts receiving lower doses (75–150 mg/m2) had 16-month median survival. (p=NS) The 10 pts with negative margins has a MS of 25.8 months while 19 pts with positive margins had a 13.4 month MS (p=NS). MS for 20 pts with N2 (-) nodes was 30 months and for 9 pts with N2 (+) 13 months (p= 0.0115). MS for 18 pts with BWH/DFCI stage 1–2 was 32 months and for the 11 stage 3 pts 14 months (p=0.0022). Conclusions: 1) IOHC was technically feasible with acceptable morbidity and mortality 2) Single dose amifostine was inadequate against cisplatin renal toxicity and MTD was not determined. 3) Stage 1–2, epithelial type or N2 (-) pts demonstrated survival greater that expected historic controls.

No significant financial relationships to disclose.

Smoking cessation is challenging even after lung cancer surgery

19507

Background: It is recommended that patients undergoing lung cancer surgery quit smoking pre-operatively to reduce peri- operative complications. Smoking cessation after diagnosis is associated with improved clinical outcomes. Few studies have examined the behavior of surgical lung cancer patients who are smokers. We sought to 1) determine the smoking prevalence rate at diagnosis; 2) identify readiness to quit and cessation strategies, 3) describe patterns of smoking overtime, and 4) identify factors (demographic, tobacco-related, and health status) correlating with smoking relapse and/or continued smoking (SR) after surgery. Methods: Ninety-four patients were enrolled in a descriptive study. Data were collected through chart review and standardized tobacco and health status questionnaires. Smoking status was assessed through self-report and measurement of urinary cotinine. The primary endpoints were smoking status at 1, 2, and 4 months after surgery. Frequencies, t-tests, and chi-square were used for analysis. Results: Eighty-four patients (89%) were ever-smokers and 35 (42%) reported smoking at diagnosis. Twenty-nine (83%) current smokers attempted cessation at diagnosis and 18 (51%) received assistance with pharmacotherapy being the most common strategy. One month post-operatively, 20 (56%) self-reported smokers planned to quit within the following month. Fifty (60%) ever-smokers remained abstinent, 13 (15%) continued smoking, and 21 (25%) relapsed. Ten (48%) of those who relapsed were former smokers and had not smoked for at least a year before diagnosis. Factors significantly associated with SR included younger age, lower education and pain. Those who relapsed were on average 7 years younger (p=0.01). Those without high school education (HS) had a significantly higher rate of relapse as compared to those with at least HS (83% vs. 48%, p=0.04). Those with pain had a higher rate of relapse as compared to those who did not have pain (73% vs. 33%, p=0.03). Conclusions: Smoking relapse rates are high after lung cancer surgery even among those who previously quit. Former and current smokers are at high risk for relapse and will require smoking cessation programs incorporating symptom management and relapse prevention.

No significant financial relationships to disclose.

Impact of pathological staging on survival in patients with epithelial mesothelioma treated with extrapleural pneumonectomy

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Objective: There is no universally accepted staging system in malignant pleural mesothelioma (MPM). A seventeen-year single institution experience of surgically treating a large epithelial MPM cohort with extrapleural pneumonectomy (EPP) gives insight to the applications and limitations of BWH/ DFCI and AJCC staging systems. Methods: We retrospectivly reviewed 526 consecutive patients with epithelial MPM who were surgically explored at our institution since 1988 with intent to perform EPP. Pathologic diagnoses of mesothelioma were confirmed and clinicopathologic data were recorded. Kaplan-Meyer survival from diagnosis was calculated. Those who underwent EPP were staged using BWH / DFCI (J Thorac Cardiov Surg 117:5463;1999) and AJCC (6th Edition) criteria. Operative deaths were included in the analysis and patients received varied adjuvant regimens. Results: Of 526 patients explored for potential EPP, 53 (10%) underwent alternative pleurectomy and 55 (11%) were unresectable. The remaining 418 (79%) underwent EPP. Of these, 307 (73%) were male. Median age at diagnosis was 57.9 years (17–78). Operative mortality was 5%. Median follow-up was 16 months and 23% of observations were censored. Overall median, 1-yr, 3-yr and 5-yr survival was: 18.9 mo., 68.8%, 26.3%, and 13.9%. The table below presents Kaplan-Meyer survival by stage. Conclusions: 1) Both pathological staging systems stratify survival in this cohort, although each system is limited in that a majority of patients are classified as stage 3. 2) BWH / DFCI criteria identify more stage 1–2 patients with favorable prognosis, 164 (39%) vs 46 (11%). 3) AJCC criteria classify more patients to stage 4, 76 (18%) vs 4 (1%), but appear to identify some patients with relatively favorable prognosis. 4) Selected criteria from both systems might be combined to optimally stratify patients with epithelial MPM undergoing EPP.

No significant financial relationships to disclose.

[Table: see text]

Expression patterns of inhibitor of apoptosis proteins in malignant pleural mesothelioma

Inhibitor of apoptosis proteins (IAPs) comprise a family of structurally similar proteins, five of which are widely studied in the context of cancer: IAP-1/MIHC/cIAP2, IAP-2/MIHB/cIAP1, livin/ML-IAP/KIAP, survivin, and XIAP/MIHA/hILP. IAPs are overexpressed by most neoplasms, promote tumour cell survival after a wide variety of apoptotic stimuli, and frequently have gene and/or protein expression patterns associated with a relatively poor prognosis. However, many IAPs are also expressed by normal tissues, can facilitate apoptotic cell death, and have expression patterns associated with a relatively favourable prognosis in some cases. The result is that the precise role(s) of IAPs in human tumours is not exactly known. It has been previously reported that IAP-1 is overexpressed in malignant pleural mesothelioma (MPM) and is responsible for a large degree of the resistance of cultured MPM cells to cisplatin. Given the high homology of IAP family members, it is likely that other IAPs will be important in MPM. In the present study, the gene and protein expression patterns of IAP-1, IAP-2, survivin, livin, and XIAP have been determined in MPM cell lines (n=9) and a large number of MPM tumours using high-density oligonucleotide microarrays (n=40) and an MPM tissue array (n=66). Human tumours were linked to clinical data and it was found that IAP-1 and survivin mRNA expression patterns were associated with a relatively shorter patient survival, while those of XIAP and livin were associated with a relatively longer patient survival. Abundant protein for all IAPs was also detected in MPM tumours, where they were expressed primarily in the cytoplasm. Only IAP-1 and livin protein was expressed in the nucleus of MPM tumours. These results provide the rationale for additional study of this gene family in MPM and cancer in general.

Inhibitor of apoptosis proteins are regulated by tumour necrosis factor-alpha in malignant pleural mesothelioma

Inhibitor of apoptosis proteins (IAPs) are overexpressed by most neoplasms and promote tumour cell survival after a wide variety of apoptotic stimuli elicited via intrinsic (ie mitochondrial) and extrinsic (ie death receptor) pathways. It has previously been reported that one of these proteins, IAP-1(MIHC/cIAP2), is overexpressed in malignant pleural mesothelioma (MPM) and is responsible for a large degree of the resistance of cultured MPM cells to cisplatin. Subsequent analysis in a larger number of human tumours revealed that additional IAPs (eg IAP-2/MIHB/cIAP1, livin/ML-IAP/KIAP, survivin, and XIAP/MIHA/hILP) are also overexpressed in MPM and, with the exception of IAP-2, have expression patterns that correlate with prognosis. In the present study, potential regulatory mechanisms of IAP genes in MPM were investigated and it was found that tumour necrosis factor-alpha (TNF-alpha) can increase mRNA and protein levels of IAP-1, IAP-2, and XIAP, but not livin or survivin in MPM cell lines (n=4). It was also found that IAP gene expression levels are increased concomitantly with translocation to the nucleus of the TNF-responsive transcription factor NF-kappaB. Co-incubation of MPM cells with TNF-alpha and pyrrolidine dithiocarbamate (PDTC), an NF-kappaB inhibitor, prevented TNF-mediated up-regulation of IAP gene expression levels. In survival studies, TNF-alpha was not toxic to MPM cells at any concentration examined. However, MPM cells exposed to TNF-alpha were twice as resistant to cisplatin in dose response survival assays compared with unstimulated controls and were found to have a significantly greater fraction of surviving cells at multiple cisplatin concentrations (p<0.0087). Finally, it was found that levels of circulating TNF-alpha were statistically significantly (p=0.031) (median 312.5 pg/ml) higher in MPM patients (n=6) prior to surgical tumour debulking compared with those after surgery (median 0 pg/ml). These results when combined with previous observations by our laboratory and others strongly suggest that IAPs act synergistically with TNF family members to promote survival of MPM tumour cells after exposure to cisplatin and possibly other chemotherapeutic drugs.