Illuminating gravitational waves: A concordant picture of photons from a neutron star merger

Merging neutron stars offer an excellent laboratory for simultaneously studying strong-field gravity and matter in extreme environments. We establish the physical association of an electromagnetic counterpart (EM170817) with gravitational waves (GW170817) detected from merging neutron stars. By synthesizing a panchromatic data set, we demonstrate that merging neutron stars are a long-sought production site forging heavy elements by r-process nucleosynthesis. The weak gamma rays seen in EM170817 are dissimilar to classical short gamma-ray bursts with ultrarelativistic jets. Instead, we suggest that breakout of a wide-angle, mildly relativistic cocoon engulfing the jet explains the low-luminosity gamma rays, the high-luminosity ultraviolet-optical-infrared, and the delayed radio and x-ray emission. We posit that all neutron star mergers may lead to a wide-angle cocoon breakout, sometimes accompanied by a successful jet and sometimes by a choked jet.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Vancomycin-resistant enterococci carriage in an acute Irish hospital

BACKGROUND

Ireland has been shown to have the highest rate of vancomycin-resistant enterococci (VRE) in cases of bacteraemia in Europe, according to a report in 2014 from the European Antimicrobial Resistance Surveillance System Network.

AIM

To investigate the prevalence of VRE gut colonization in a cohort of patients in 2014 at Cork University Hospital (CUH) by performing a cross-sectional study using faecal samples submitted to the microbiology laboratory for routine investigation from both hospital inpatients and community-based patients.

METHODS

Faeces were examined for VRE colonization using selective cultivation, antimicrobial susceptibility testing, and speciation using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. All VRE isolates were evaluated by molecular means for resistance determinants, type, and Insertion Sequence 16 as an indicator of Clonal Complex 17 (CC17).

FINDINGS

From the 350 specimens investigated, 67 (19.1%) specimens were positive for VRE [95% confidence interval (CI): 15.0-23.2]. The prevalence of VRE colonization among CUH patients tested in this study (N = 194) was 31.4% (95% CI: 24.7-38.1). By contrast, the general practitioner patient samples (N=29) showed a prevalence of 0%, whereas 22.2% of samples from other hospitals (N=27) were positive for VRE. All isolates were Enterococcus faecium (VREfm) and were indicated to contain CC17, though with considerable heterogeneity among the isolates.

CONCLUSION

This high prevalence goes some way towards providing an explanation for the current high rates of VRE bacteraemia in Ireland, as well as highlighting the benefits of screening and enhanced infection control practices by all hospitals to control the high rates of VRE observed.

Acute Neurological Illness in a Kidney Transplant Recipient Following Infection With Enterovirus-D68: An Emerging Infection?

We report the first case of enterovirus-D68 infection in an adult living-donor kidney transplant recipient who developed rapidly progressive bulbar weakness and acute flaccid limb paralysis following an upper respiratory infection. We present a 45-year-old gentleman who underwent pre-emptive living-donor kidney transplantation for IgA nephropathy. Eight weeks following transplantation, he developed an acute respiratory illness from enterovirus/rhinovirus that was detectable in nasopharyngeal (NP) swabs. Within 24 h of onset of respiratory symptoms, the patient developed binocular diplopia which rapidly progressed to multiple cranial nerve dysfunctions (acute bulbar syndrome) over the next 24 h. Within the next 48 h, asymmetric flaccid paralysis of the left arm and urinary retention developed. While his neurological symptoms were evolving, the Centers for Disease Control reported that the enterovirus strain from the NP swabs was, in fact, Enterovirus-D68 (EV-D68). Magnetic resonance imaging of the brain demonstrated unique gray matter and anterior horn cell changes in the midbrain and spinal cord, respectively. Constellation of these neurological symptoms and signs was suggestive for postinfectious encephalomyelitis (acute disseminated encephalomyelitis [ADEM]) from EV-D68. Treatment based on the principles of ADEM included intensive physical therapy and other supportive measures, which resulted in a steady albeit slow improvement in his left arm and bulbar weakness, while maintaining stable allograft function.

IκBβ enhances the generation of the low-affinity NFκB/RelA homodimer

The NFκB family of dimeric transcription factors regulate inflammatory and immune responses. While the dynamic control of NFκB dimer activity via the IκB-NFκB signalling module is well understood, there is little information on how specific dimer repertoires are generated from Rel family polypeptides. Here we report the iterative construction-guided by in vitro and in vivo experimentation-of a mathematical model of the Rel-NFκB generation module. Our study reveals that IκBβ has essential functions within the Rel-NFκB generation module, specifically for the RelA:RelA homodimer, which controls a subset of NFκB target genes. Our findings revise the current dogma of the three classical, functionally related IκB proteins by distinguishing between a positive 'licensing' factor (IκBβ) that contributes to determining the available NFκB dimer repertoire in a cell's steady state, and negative feedback regulators (IκBα and -ɛ) that determine the duration and dynamics of the cellular response to an inflammatory stimulus.

Precision of computed tomography urography in diagnosing transitional cell carcinoma

Introduction:

Computed tomography urography (CTU) has largely replaced excretion urography. Indications for CTU include patients with haematuria and for upper tract surveillance in those with known transitional cell carcinoma (TCC). Reporting of a possible TCC can lead to complex clinical decisions regarding further investigation and management. The aim of this study is to ascertain the positive predictive value (PPV) of such reports in a large tertiary centre.

Methods:

Examinations performed from January 2010 to August 2012 were retrospectively identified. Subsequent diagnosis of TCC was confirmed by histology, cytology or accepted by uro-oncology MDT with absence of histological proof. The PPV of reported TCCs was calculated overall, by tumour site and presentation.

Results:

A total of 1199 CTU investigations were performed. Analysis revealed the PPV of a reported TCC was 67% for kidney, 44% for ureteric and 85% for bladder lesions. Overall PPV was 68% and 51% for the upper tracts. In patients who attended the haematuria clinic, the PPV was 82% and 88% when positive cytology was included.

Conclusion:

CTU is an appropriate replacement for excretion urography. However, prompt invasive assessment of the entire urinary tract still remains necessary to confirm a suspected TCC.

Increased risk of genetic and epigenetic instability in human embryonic stem cells associated with specific culture conditions

The self-renewal and differentiation capacities of human pluripotent stem cells (hPSCs) make them a promising source of material for cell transplantation therapy, drug development, and studies of cellular differentiation and development. However, the large numbers of cells necessary for many of these applications require extensive expansion of hPSC cultures, a process that has been associated with genetic and epigenetic alterations. We have performed a combinatorial study on both hESCs and hiPSCs to compare the effects of enzymatic vs. mechanical passaging, and feeder-free vs. mouse embryonic fibroblast feeder substrate, on the genetic and epigenetic stability and the phenotypic characteristics of hPSCs. In extensive experiments involving over 100 continuous passages, we observed that both enzymatic passaging and feeder-free culture were associated with genetic instability, higher rates of cell proliferation, and persistence of OCT4/POU5F1-positive cells in teratomas, with enzymatic passaging having the stronger effect. In all combinations of culture conditions except for mechanical passaging on feeder layers, we noted recurrent deletions in the genomic region containing the tumor suppressor gene TP53, which was associated with decreased mRNA expression of TP53, as well as alterations in the expression of several downstream genes consistent with a decrease in the activity of the TP53 pathway. Among the hESC cultures, we also observed culture-associated variations in global gene expression and DNA methylation. The effects of enzymatic passaging and feeder-free conditions were also observed in hiPSC cultures. Our results highlight the need for careful assessment of the effects of culture conditions on cells intended for clinical therapies.

Isolation & identification of bacteria for the treatment of brown crab (Cancer pagurus) waste to produce chitinous material

AIMS

To isolate bacteria from soil for microbial pretreatment of brown crab (Cancer pagurus) shell waste and the production of chitin.

METHODS AND RESULTS

Isolates were screened for protease enzymes and acid production in order to facilitate the removal of protein and calcium carbonate fractions from brown crab shell to yield a chitinous material. Selected isolates were applied in various combinations in successive, two-step fermentations with brown crab shell waste. These isolates were identified as: Exiguobacterium spp. (GenBank accession number: KP050496), Bacillus cereus (GenBank accession number: KP050499), B. subtilis (GenBank accession number: KP050498), Bacillus licheniformis (GenBank accession number: KP050497), Pseudomonas migulae (GenBank accession number: KP050501), Pseudomonas spp. (GenBank accession number: KP050500), Pseudomonas spp. (GenBank accession number: KP050502), Arthrobacter luteolus (GenBank accession number: KP050503), Lactobacillus spp. (GenBank accession number: KP072000) and Enterococcus spp. (GenBank accession number: KP071999).

CONCLUSIONS

Successive two-step fermentations with isolates in certain combinations resulted in a demineralization of >94% and the extraction of a crude chitin fraction from brown crab processing waste. The highest demineralization, 98·9% was achieved when isolates identified as B. cereus and Pseudomonas spp. were used in combination. The transfer of fermentations to a larger scale requires further research for optimization.

SIGNIFICANCE AND IMPACT OF THE STUDY

The successful application of these isolates in successive two-step fermentation of brown crab shell waste to extract chitin means with further research into optimization and scale up, this chitin extraction process may be applied on an industrial scale and provide further commercial value from brown crab shell waste.

Risk of lymphoma subtypes after solid organ transplantation in the United States

BACKGROUND

Solid organ transplant recipients have high risk of lymphomas, including non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL). A gap in our understanding of post-transplant lymphomas involves the spectrum and associated risks of their many histologic subtypes.

METHODS

We linked nationwide data on solid organ transplants from the US Scientific Registry of Transplant Recipients (1987-2008) to 14 state and regional cancer registries, yielding 791 281 person-years of follow-up for 19 distinct NHL subtypes and HL. We calculated standardised incidence ratios (SIRs) and used Poisson regression to compare SIRs by recipient age, transplanted organ, and time since transplantation.

RESULTS

The risk varied widely across subtypes, with strong elevations (SIRs 10-100) for hepatosplenic T-cell lymphoma, Burkitt's lymphoma, NK/T-cell lymphoma, diffuse large B-cell lymphoma, and anaplastic large-cell lymphoma (both systemic and primary cutaneous forms). Moderate elevations (SIRs 2-4) were observed for HL and lymphoplasmacytic, peripheral T-cell, and marginal zone lymphomas, but SIRs for indolent lymphoma subtypes were not elevated. Generally, SIRs were highest for younger recipients (<20 years) and those receiving organs other than kidneys.

CONCLUSION

Transplant recipients experience markedly elevated risk of a distinct spectrum of lymphoma subtypes. These findings support the aetiologic relevance of immunosuppression for certain subtypes and underscore the importance of detailed haematopathologic workup for transplant recipients with suspected lymphoma.

Hospital Episode Statistics data analysis of postoperative venous thromboembolus in patients undergoing urological surgery: a review of 126,891 cases

Introduction

Current guidelines on venous thromboembolism (VTE) prevention do not reflect the potential varying risk for patients undergoing different urological procedures. Our study aimed to establish the procedure specific rate of postoperative VTE in patients undergoing urological surgery.

Methods

Hospital Episode Statistics were obtained for all patients undergoing common urological procedures between April 2009 and April 2010. This cohort was followed up to identify all patients reattending with either deep vein thrombosis (DVT) or pulmonary embolism (PE) within 12 months.

Results

A total of 126,891 individuals underwent urological surgery during the study period. This included 89,628 men (70.6%) and 37,236 women (29.3%) with a mean age of 65.2 years. At the 12-month follow-up, 839 patients (0.66%) were readmitted with VTE. Of these, 373 (0.29%) were admitted with DVT and 466 (0.37%) with PE. The procedure-specific rate of VTE varied significantly between 2.86% following cystectomy and 0.23% following urethral dilatation. Procedures performed in the lithotomy position carried a significantly lower risk of VTE than those performed in the supine position (0.60% vs 1.28%, p<0.0001). Furthermore, of all procedures performed in the lithotomy position, those performed on benign conditions carried a significantly lower risk than those performed on malignant disease (0.52% vs 0.79%, p<0.0001).

Conclusions

Procedure specific rates of postoperative VTE vary widely among patients undergoing urological procedures. These findings suggest the potential benefit of prolonging the use of thromboprophylaxis in high-risk patients but also exploring the apparent lack of need for routine thromboprophylaxis in patients undergoing low-risk procedures.

Clinical implications of machine-probe combinations on obstetric ultrasound measurements used in pregnancy dating

OBJECTIVE

To investigate the effect of use of different machine-probe combinations on measurement variability and to assess how this variability impacts on accuracy of pregnancy dating.

METHODS

Sixteen different ultrasound machine-probe combinations were used for lateral measurement of targets spaced 10 and 40 mm apart and axial measurement of targets spaced 10 and 50 mm apart in an ultrasound phantom, and differences between the measured and true values were determined. The mean of the 40-mm lateral measurements was used to estimate gestational age using standard obstetric dating tables for crown-rump length (CRL) and femur length (FL) and the mean of the 50-mm axial measurements was used to estimate gestational age using the obstetric dating tables for biparietal diameter (BPD).

RESULTS

As absolute measurements became larger, differences observed using different machine-probe combinations exceeded those due to intraobserver variability. Maximum dating differences for first-trimester CRL of 2 days (based on a measured CRL range of 39-42 mm), second-trimester BPD of 4 days (based on a measured BPD range of 49-52 mm) and FL of 9 days (based on a measured FL range of 39-42 mm) were observed when measurements were transposed to the equivalent gestational age using standard charts.

CONCLUSION

Differences between measured and true values of biometric measurements reflect both machine-probe and intraobserver variability. Incremental first-trimester CRL growth with time is rapid, but second-trimester FL growth is much less so, leaving this lateral measurement more prone to both observer and machine-probe errors. The only axial growth measurement commonly performed is BPD where the measurement differences were intermediate between those of CRL and FL. The differences that can be ascribed to different equipment combinations are in many cases greater than those expected in clinical practice and are of potential importance in determining how fetal biometry is used for dating pregnancies.

Dynamic changes in the copy number of pluripotency and cell proliferation genes in human ESCs and iPSCs during reprogramming and time in culture

Genomic stability is critical for the clinical use of human embryonic and induced pluripotent stem cells. We performed high-resolution SNP (single-nucleotide polymorphism) analysis on 186 pluripotent and 119 nonpluripotent samples. We report a higher frequency of subchromosomal copy number variations in pluripotent samples compared to nonpluripotent samples, with variations enriched in specific genomic regions. The distribution of these variations differed between hESCs and hiPSCs, characterized by large numbers of duplications found in a few hESC samples and moderate numbers of deletions distributed across many hiPSC samples. For hiPSCs, the reprogramming process was associated with deletions of tumor-suppressor genes, whereas time in culture was associated with duplications of oncogenic genes. We also observed duplications that arose during a differentiation protocol. Our results illustrate the dynamic nature of genomic abnormalities in pluripotent stem cells and the need for frequent genomic monitoring to assure phenotypic stability and clinical safety.

Nuclear export of the NF-κB inhibitor IκBα is required for proper B cell and secondary lymphoid tissue formation

The N-terminal nuclear export sequence (NES) of inhibitor of nuclear factor kappa B (NF-κB) alpha (IκBα) promotes NF-κB export from the cell nucleus to the cytoplasm, but the physiological role of this export regulation remains unknown. Here we report the derivation and analysis of genetically targeted mice harboring a germline mutation in IκBα NES. Mature B cells in the mutant mice displayed nuclear accumulation of inactive IκBα complexes containing a NF-κB family member, cRel, causing their spatial separation from the cytoplasmic IκB kinase. This resulted in severe reductions in constitutive and canonical NF-κB activities, synthesis of p100 and RelB NF-κB members, noncanonical NF-κB activity, NF-κB target gene induction, and proliferation and survival responses in B cells. Consequently, mice displayed defective B cell maturation, antibody production, and formation of secondary lymphoid organs and tissues. Thus, IκBα nuclear export is essential to maintain constitutive, canonical, and noncanonical NF-κB activation potentials in mature B cells in vivo.

Intraoperative radiotherapy and colorectal cancer

Intraoperative radiotherapy (IORT) is a highly specialized component of multidisciplinary management of advanced and recurrent colorectal cancer. The aim of this review was to assess its role and effectiveness in the management of colorectal cancer. A literature search was performed using Medline, Embase, Ovid and Cochrane to identify English language studies which have used IORT in the multidisciplinary management of primary and recurrent colon and rectal cancers. Improved survival and local control in patients with involved surgical margins treated with IORT have been shown in many studies, but these results have been mainly from retrospective studies. There is associated morbidity from IORT. IORT does have a role in the management of colorectal cancer. Further research needs to be performed to optimize the application of this therapy.