Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run

We report on a search for compact binary coalescences where at least one binary component has a mass between 0.2  M_{⊙} and 1.0  M_{⊙} in Advanced LIGO and Advanced Virgo data collected between 1 April 2019 1500 UTC and 1 October 2019 1500 UTC. We extend our previous analyses in two main ways: we include data from the Virgo detector and we allow for more unequal mass systems, with mass ratio q≥0.1. We do not report any gravitational-wave candidates. The most significant trigger has a false alarm rate of 0.14  yr^{-1}. This implies an upper limit on the merger rate of subsolar binaries in the range [220-24200]  Gpc^{-3} yr^{-1}, depending on the chirp mass of the binary. We use this upper limit to derive astrophysical constraints on two phenomenological models that could produce subsolar-mass compact objects. One is an isotropic distribution of equal-mass primordial black holes. Using this model, we find that the fraction of dark matter in primordial black holes in the mass range 0.2  M_{⊙}<m_{PBH}<1.0  M_{⊙} is f_{PBH}≡Ω_{PBH}/Ω_{DM}≲6%. This improves existing constraints on primordial black hole abundance by a factor of ∼3. The other is a dissipative dark matter model, in which fermionic dark matter can collapse and form black holes. The upper limit on the fraction of dark matter black holes depends on the minimum mass of the black holes that can be formed: the most constraining result is obtained at M_{min}=1  M_{⊙}, where f_{DBH}≡Ω_{DBH}/Ω_{DM}≲0.003%. These are the first constraints placed on dissipative dark models by subsolar-mass analyses.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

First report of molecular and phylogenetic analysis of Physaloptera praeputialis in naturally infected stray cats from India

Nematodes of the genus Physaloptera are globally distributed and infect a multitude of hosts. Their life cycle involves orthopterans and coleopterans as intermediate hosts. The morphological characters alone are inadequate to detect and differentiate Physaloptera spp. from its congeners. Moreover, molecular studies are limited to compare them precisely. The present communication reports the first molecular phylogenetic characterization of feline Physaloptera spp. from India based on mitochondrial cytochrome c oxidase subunit 1 (COX1) and small subunit ribosomal DNA (18S rDNA). The nematodes were first isolated from the stomach of adult stray cats during necropsy examination. Based on the gross and microscopic characters, the worms were identified as P. praeputialis. Morphological identification was further confirmed through PCR targeting the barcode region of the mitochondrial cytochrome c oxidase subunit I (MT-COI) gene, using nematode-specific primers cocktail followed by species specific primers targeting partial COX1 and 18S rRNA genes. Generated sequences were submitted in NCBI GenBank (MW517846, MW410927, MW411349), and phylogenetic trees were constructed using the maximum likelihood method. When compared with other sequences of Physaloptera species across the globe, the present isolates showed 85.6-97.7% and 97.3-99% nucleotide homology based on COX1 and 18S rRNA gene, respectively. BLASTn analysis revealed a strong identity to other Physaloptera spp., and the phylogenetic tree placed all Physaloptera spp. in the same cluster. This study again indicates the usefulness of molecular techniques to substantiate the identity of species that may lack adequate descriptions and impart new insight for the potentially overlooked significance of P. praeputialis infections in felines.

Trophoblast uptake of DBP regulates intracellular actin and promotes matrix invasion

Early pregnancy is characterised by elevated circulating levels of vitamin D binding protein (DBP). The impact of this on maternal and fetal health is unclear but DBP is present in the placenta, and DBP gene variants have been linked to malplacentation disorders such as preeclampsia. The functional role of DBP in the placenta was investigated using trophoblastic JEG3, BeWo and HTR8 cells. All three cell lines showed intracellular DBP with increased expression and nuclear localisation of DBP in cells treated with the active form of vitamin D, 1,25-dihydroxyvitamin D (1,25D). When cultured in the serum of mice lacking DBP (DBP-/-), JEG3 cells showed no intracellular DBP indicating uptake of exogenous DBP. Inhibition of the membrane receptor for DBP, megalin, also suppressed intracellular DBP. Elimination of intracellular DBP with DBP-/- serum or megalin inhibitor suppressed matrix invasion by trophoblast cells and was associated with increased nuclear accumulation of G-actin. Conversely, treatment with 1,25D enhanced matrix invasion. This was independent of the nuclear vitamin D receptor but was associated with enhanced ERK phosphorylation, and inhibition of ERK kinase suppressed trophoblast matrix invasion. When cultured with serum from pregnant women, trophoblast matrix invasion correlated with DBP concentration, and DBP was lower in first-trimester serum from women who later developed preeclampsia. These data show that the trophoblast matrix invasion involves uptake of serum DBP and associated intracellular actin-binding and homeostasis. DBP is a potential marker of placentation disorders such as preeclampsia and may also provide a therapeutic option for improved placenta and pregnancy health.

GW190521: A Binary Black Hole Merger with a Total Mass of 150 M_{⊙}

On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85_{-14}^{+21}  M_{⊙} and 66_{-18}^{+17}  M_{⊙} (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova processes, with only a 0.32% probability of being below 65  M_{⊙}. We calculate the mass of the remnant to be 142_{-16}^{+28}  M_{⊙}, which can be considered an intermediate mass black hole (IMBH). The luminosity distance of the source is 5.3_{-2.6}^{+2.4}  Gpc, corresponding to a redshift of 0.82_{-0.34}^{+0.28}. The inferred rate of mergers similar to GW190521 is 0.13_{-0.11}^{+0.30}  Gpc^{-3} yr^{-1}.

Thenar lumps: a review of differentials

Most soft-tissue lumps in the hand are benign, with ganglions being the commonest, but in the thenar region, solid soft-tissue masses are more common than a ganglion. In this review, we focus on soft-tissue lesions (neoplastic and non-neoplastic) presenting as a palpable lump in this region. A specific diagnosis can often be reached using ultrasonography and/or magnetic resonance imaging. Most of these lesions are managed in local hospitals or primary care, whereas some are referred to specialist centres. This review article will help both general and musculoskeletal radiologists to diagnose and characterise these lesions, provide a guide for further imaging, and provide an insight into imaging features that may need specific investigations such as core biopsy, tertiary referral, and further review at multidisciplinary meetings.

Comparison of Germline versus Somatic BAP1 Mutations for Risk of Metastasis in Uveal Melanoma

BACKGROUND

Germline mutations in BAP1 have been associated with BAP1-Tumor Predisposition Syndrome (BAP1-TPDS), a predisposition to multiple tumors within a family that includes uveal melanoma (UM), cutaneous melanoma, malignant mesothelioma and renal cell carcinoma. Alternatively, somatic mutations in BAP1 in UM have been associated with high risk for metastasis. In this study, we compare the risk of metastasis in UM that carry germline versus somatic BAP1 mutations and mutation-negative tumors.

METHODS

DNA extracted from 142 UM and matched blood samples was sequenced using Sanger or next generation sequencing to identify BAP1 gene mutations.

RESULTS

Eleven of 142 UM (8%) carried germline BAP1 mutations, 43 (30%) had somatic mutations, and 88 (62%) were mutation-negative. All BAP1 mutations identified in blood samples were also present in the matched UM. There were 52 unique mutations in 54 tumors. All were pathogenic or likely pathogenic. A comparison of tumors carrying somatic vs. germline mutations, or no mutations, showed a higher frequency of metastasis in tumors carrying somatic mutations: 74% vs. 36%, P=0.03 and 74% vs. 26% P<0.001, respectively. Tumors with a somatic mutation compared to mutation-negative had an older age of diagnosis of (61.8 vs. 52.2 years, P=0.002), and shorter time to metastasis (16 vs. 26 months, P=0.04). Kaplan-Meier analysis further showed that tumors with somatic (vs. germline) mutations demonstrated a greater metastatic risk (P=0.03). Cox multivariate analysis showed in addition to chromosome-3 monosomy and larger tumor diameter, the presence of BAP1 somatic, but not germline mutations, was significantly associated with risk of metastasis(P=0.02). Personal or family history of BAP1-TPDS was available for 79 of the cases. All eight cases with germline mutations reported a history of BAP1-TPDS, which was significantly greater than what was observed in cases with somatic mutations (10 of 23, P=0.009) or mutation-negative cases (11 of 48, P<0.001).

CONCLUSIONS

Defining germline vs. somatic nature of BAP1 mutations in UM can inform the individual about both the risk of metastasis, and the time to metastasis, which are critically important outcomes for the individual. This information can also change the cascade screening and surveillance of family members.

Vitamin D, the placenta and early pregnancy: effects on trophoblast function

Pregnancy is associated with significant changes in vitamin D metabolism, notably increased maternal serum levels of active vitamin D, 1,25-dihydroxyvitamin (1,25(OH)₂D). This appears to be due primarily to increased renal activity of the enzyme 25-hydroxyvitamin D-1α-hydroxylase (CYP27B1) that catalyzes synthesis of 1,25(OH)₂D, but CYP27B1 expression is also prominent in both the maternal decidua and fetal trophoblast components of the placenta. The precise function of placental synthesis of 1,25(OH)₂D remains unclear, but is likely to involve localized tissue-specific responses with both decidua and trophoblast also expressing the vitamin D receptor (VDR) for 1,25(OH)₂D. We have previously described immunomodulatory responses to 1,25(OH)₂D by diverse populations of VDR-expressing cells within the decidua. The aim of the current review is to detail the role of vitamin D in pregnancy from a trophoblast perspective, with particular emphasis on the potential role of 1,25(OH)₂D as a regulator of trophoblast invasion in early pregnancy. Vitamin D deficiency is common in pregnant women, and a wide range of studies have linked low vitamin D status to adverse events in pregnancy. To date, most of these studies have focused on adverse events later in pregnancy, but the current review will explore the potential impact of vitamin D on early pregnancy, and how this may influence implantation and miscarriage.

Association of heat stress protein 90 and 70 gene polymorphism with adaptability traits in Indian sheep (Ovis aries)

Heat stress proteins assist cellular proteins in the acquisition of native structure. The present research was conducted to study how thermo-tolerance is modulated by HSP90 and HSP70 gene polymorphism and its association with hemato-physio-biochemical parameters, supported by their expression profiles in Chokla, Magra, Marwari, and Madras Red sheep breeds. Least square analysis revealed significant effect (P < 0.05) of season and breed on all the physiological parameters, i.e., temperature, respiratory rate, and pulse rate (a.m. and p.m.), as well as hematological parameters like Hb, packed cell volume, total erythrocyte count (TEC), neutrophil/lymphocyte (N/L) ratio, and total leukocyte count (TLC). There was a significant influence (P < 0.05) of breed on biochemical parameters such as glucose, SGOT, phosphorous, triglyceride, and cholesterol. Eight fragments were amplified and sequenced in HSP90, and 70 genes and 13 single-nucleotide polymorphisms (SNPs) were identified. Tetra-primer amplification refractory mutation system PCR, PCR-RFLP, and allele-specific PCR genotyping protocols were developed for large-scale genotyping of five SNPs. A significant difference (P < 0.05) of rectal temperature (a.m.), respiratory rate (p.m.), triglyceride, and total protein was observed at SNP01; albumin at SNP2; pulse rate (p.m.) at SNP3; and rectal temperature (p.m.), pulse rate (p.m.), Hb (g/dL), and N/L ratio at SNP4 and TLC at SNP5. Gene expression analysis revealed higher expression in less adapted animals with Madras Red < Magra < Chokla < Marwari expression pattern [corrected]. Predominant allele was found to be superior in most of the SNPs (SNP1-4) indicating the selection acting in directional manner (positive selection). Finally, it is concluded that TACCA haplotype combination of SNP1-SNP2-SNP3-SNP4-SNP5 might be of some selection advantage for the identification of animals more adaptable to heat stress.

A systematic review of ultrasound-guided FNA of lesions in the head and neck--focusing on operator, sample inadequacy and presence of on-spot cytology service

The objective of this review is to perform a systematic review of ultrasound-guided fine-needle aspiration (FNA) services for head and neck lesions with assessment of inadequacy rates and related variables such as the presence of immediate cytological assessment. A computer-based systematic search of articles in English language was performed using MEDLINE (1950 to date) from National Health Service evidence healthcare database and PubMed. Full texts of all relevant articles were obtained and scrutinized independently by two authors according to the stated inclusion and exclusion criteria. The primary search identified 932 articles, but only 78 met all the study criteria. The overall inadequacy rate was 9.3%, 16 studies had on-site evaluation by a cytopathologist/specialist clinician with a rate of 6.0%. In seven studies, a cytotechnician was available to either assess the sample or prepare the slides with an average inadequacy rate of 11.4%. In 1 study, the assessment was unclear, but the inadequacy rate for the remaining 54 studies, without immediate assessment, was 10.3%. The rate for the cytopathologist/specialist clinicians was significantly different to no on-site assessment but this was not found for assessment by cytotechnicians. The review suggests that the best results are obtained with a cytopathologist-led FNA service, where the pathologist reviews the specimen immediately, in relation to the clinical context, thereby deciding on adequacy and need for further biopsies. A systematic review looking at ultrasound-guided FNA of head and neck lesions has not been published previously.

Severe and moderate haemophilia A and B in US females

Haemophilia A and B are rare X-lined hemorrhagic disorders that typically affect men. Women are usually asymptomatic carriers, but may be symptomatic and, rarely, also express severe (factor VIII (FVIII) or factor IX (FIX) <0.01 U mL(-1)) or moderately severe (FVIII/FIX 0.01-0.05 U mL(-1)) phenotypes. However, data on clinical manifestations, genotype and the psychosocial ramifications of illness in severely affected females remain anecdotal. A national multi-centre retrospective study was conducted to collect a comprehensive data set on affected US girls and women, and to compare clinical observations to previously published information on haemophilic males of comparable severity and mildly affected haemophilic females. Twenty-two severe/moderate haemophilia A/B subjects were characterized with respect to clinical manifestations and disease complications; genetic determinants of phenotypic severity; and health-related quality of life (HR-QoL). Clinical data were compared as previously indicated. Female patients were older than male patients at diagnosis, but similarly experienced joint haemorrhage, disease- and treatment-related complications and access to treatment. Gynaecological and obstetrical bleeding was unexpectedly infrequent. F8 or F9 mutations, accompanied by extremely skewed X-chromosome inactivation pattern (XIP), were primary determinants of severity. HR-QoL was diminished by arthropathy and viral infection. Using systematic case verification of participants in a national surveillance registry, this study elucidated the genetics, clinical phenotype and quality of life issues in female patients with severe/moderate haemophilia. An ongoing international case-controlled study will further evaluate these observations. Novel mechanistic questions are raised about the relationship between XIP and both age and tissue-specific FVIII and FIX expression.

Prenatal diagnosis in haemophilia A: experience of the genetic diagnostic laboratory

The paper describes the experience of the Genetic Diagnostic Laboratory in prenatal testing for haemophilia A, an X-linked recessive disease caused by mutations in the F8 gene. Knowledge of a familial mutation prior to pregnancy can benefit prenatal diagnosis and decrease wait time for molecular testing during pregnancy. This is a retrospective review of a series of pregnant women who pursued F8 gene testing from December 1997 through May 2012, highlighting three cases, which demonstrate the technical complexities of analysis and the implications of not knowing carrier status prior to pregnancy. Mutations of the F8 gene were detected in affected males, obligate female carriers and suspected female carriers by DNA sequencing, inverse-PCR, qRT-PCR, Southern blot and exonic dosage analysis. The same methods were used to analyse prenatal samples from obligate or suspected female carriers upon request. Maternal cell contamination studies were performed for all prenatal samples analysed. Ninety-nine women pursued F8 testing during pregnancy, either for carrier status alone or carrier status and prenatal diagnosis. Ninety-one women (91%) requested carrier testing because they did not know their F8 mutation carrier status prior to pregnancy. Eight women requested prenatal diagnosis only, and only 4 of these were aware of their mutation status. Thirty-seven individuals were found to be mutation carriers. Forty-two prenatal samples were received for prenatal diagnosis. In total 21 foetuses were identified as mutation carriers. Mutation detection was complex and increased the turnaround time in some cases. Only four of 99 women who submitted samples for F8 testing were aware of their F8 mutation status prior to pregnancy. Knowledge of F8 mutation status prior to pregnancy allows for efficient prenatal diagnosis, when desired. Thus, preconception genetic counselling is required to inform patients of the available options and the complex and time-consuming nature of F8 testing.

Dengue: a growing menace -- a snapshot of recent facts, figures & remedies

Dengue is specially owing to inadequate water supply and poor solid waste management , which are favorable for multiplication of the main vectors including the Aedes ageypti coupled with lack of proven anti viral therapy and no proven efficient vaccine .there are many cases of both dengue shock syndrome and dengue haemmorhagic fever making it a major public health burden sending ominous signal resulting both rising morbidity & mortality, deleterious effect on DALY [disability adjusted life year] & QALY [quality adjusted life year] & though it affect all section of society ,still it affect the poor & underprivileged section more, thereby growing menace in public health in general & in developing countries in particular.

Burden of respiratory tract infections among paediatric in and out-patient units during 2010-11

INTRODUCTION

Respiratory tract infections due to viral etiology were studied with an objective to identify and compare the pathogens between Hospital Indoor and Outdoor Units.

MATERIALS AND METHODS

A hospital-based cross-sectional study was conducted among children below 12 years over a period of one year. The throat and nasal swabs were collected from both the Units and screened for viral infections by real time RT-PCR technique.

RESULTS

Out of 880 samples collected, 87% and 13% were from outdoor and indoor Department with total viral positivity rate of 30% and 25% respectively. Influenza B virus (IBV) (n=126, 16%) was more prevalent in Outdoor Unit, whereas respiratory syncytial virus (RSV) (n=18, 16%) among indoor admitted cases. The multinomial logistic regression analysis revealed that both RSV and Influenza viruses were predominant in children of pre-school age groups < 5 years. In the year 2010-11, the prevalence of human metapneumovirus (HMPV) was low. The pandemic influenza A virus (pH1N1/2009) accounted for 4% (n=29) and 0.8% (n=1) cases among Outdoor and Indoor Units respectively.

CONCLUSIONS

The Outdoor Department outnumbered the Indoor Unit in terms of patient attendees and the rate of viral infections. An effective vaccination and continuous surveillance program is the need of the hour.

Genotype and phenotype correlations in 417 children with congenital hyperinsulinism

CONTEXT

Hypoglycemia due to congenital hyperinsulinism (HI) is caused by mutations in 9 genes.

OBJECTIVE

Our objective was to correlate genotype with phenotype in 417 children with HI.

METHODS

Mutation analysis was carried out for the ATP-sensitive potassium (KATP) channel genes (ABCC8 and KCNJ11), GLUD1, and GCK with supplemental screening of rarer genes, HADH, UCP2, HNF4A, HNF1A, and SLC16A1.

RESULTS

Mutations were identified in 91% (272 of 298) of diazoxide-unresponsive probands (ABCC8, KCNJ11, and GCK), and in 47% (56 of 118) of diazoxide-responsive probands (ABCC8, KCNJ11, GLUD1, HADH, UCP2, HNF4A, and HNF1A). In diazoxide-unresponsive diffuse probands, 89% (109 of 122) carried KATP mutations; 2% (2 of 122) had GCK mutations. In mutation-positive diazoxide-responsive probands, 42% were GLUD1, 41% were dominant KATP mutations, and 16% were in rare genes (HADH, UCP2, HNF4A, and HNF1A). Of the 183 unique KATP mutations, 70% were novel at the time of identification. Focal HI accounted for 53% (149 of 282) of diazoxide-unresponsive probands; monoallelic recessive KATP mutations were detectable in 97% (145 of 149) of these cases (maternal transmission excluded in all cases tested). The presence of a monoallelic recessive KATP mutation predicted focal HI with 97% sensitivity and 90% specificity.

CONCLUSIONS

Genotype to phenotype correlations were most successful in children with GLUD1, GCK, and recessive KATP mutations. Correlations were complicated by the high frequency of novel missense KATP mutations that were uncharacterized, because such defects might be either recessive or dominant and, if dominant, be either responsive or unresponsive to diazoxide. Accurate and timely prediction of phenotype based on genotype is critical to limit exposure to persistent hypoglycemia in infants and children with congenital HI.

In vitro evaluation of the imaging accuracy of C-arm conebeam CT in cerebral perfusion imaging

PURPOSE

The authors have developed a method to enable cerebral perfusion CT imaging using C-arm based conebeam CT (CBCT). This allows intraprocedural monitoring of brain perfusion during treatment of stroke. Briefly, the technique consists of acquiring multiple scans (each scan comprised of six sweeps) acquired at different time delays with respect to the start of the x-ray contrast agent injection. The projections are then reconstructed into angular blocks and interpolated at desired time points. The authors have previously demonstrated its feasibility in vivo using an animal model. In this paper, the authors describe an in vitro technique to evaluate the accuracy of their method for measuring the relevant temporal signals.

METHODS

The authors' evaluation method is based on the concept that any temporal signal can be represented by a Fourier series of weighted sinusoids. A sinusoidal phantom was developed by varying the concentration of iodine as successive steps of a sine wave. Each step corresponding to a different dilution of iodine contrast solution contained in partitions along a cylinder. By translating the phantom along the axis at different velocities, sinusoidal signals at different frequencies were generated. Using their image acquisition and reconstruction algorithm, these sinusoidal signals were imaged with a C-arm system and the 3D volumes were reconstructed. The average value in a slice was plotted as a function of time. The phantom was also imaged using a clinical CT system with 0.5 s rotation. C-arm CBCT results using 6, 3, 2, and 1 scan sequences were compared to those obtained using CT. Data were compared for linear velocities of the phantom ranging from 0.6 to 1 cm∕s. This covers the temporal frequencies up to 0.16 Hz corresponding to a frequency range within which 99% of the spectral energy for all temporal signals in cerebral perfusion imaging is contained.

RESULTS

The errors in measurement of temporal frequencies are mostly below 2% for all multiscan sequences. For single scan sequences, the errors increase sharply beyond 0.10 Hz. The amplitude errors increase with frequency and with decrease in the number of scans used.

CONCLUSIONS

Our multiscan perfusion CT approach allows low errors in signal frequency measurement. Increasing the number of scans reduces the amplitude errors. A two-scan sequence appears to offer the best compromise between accuracy and the associated total x-ray and iodine dose.

Deterministic characterization of phase noise in biomolecular oscillators

On top of the many external perturbations, cellular oscillators also face intrinsic perturbations due the randomness of chemical kinetics. Biomolecular oscillators, distinct in their parameter sets or distinct in their architecture, show different resilience with respect to such intrinsic perturbations. Assessing this resilience can be done by ensemble stochastic simulations. These are computationally costly and do not permit further insights into the mechanistic cause of the observed resilience. For reaction systems operating at a steady state, the linear noise approximation (LNA) can be used to determine the effect of molecular noise. Here we show that methods based on LNA fail for oscillatory systems and we propose an alternative ansatz. It yields an asymptotic expression for the phase diffusion coefficient of stochastic oscillators. Moreover, it allows us to single out the noise contribution of every reaction in an oscillatory system. We test the approach on the one-loop model of the Drosophila circadian clock. Our results are consistent with those obtained through stochastic simulations with a gain in computational efficiency of about three orders of magnitude.

Cerebral CT perfusion using an interventional C-arm imaging system: cerebral blood flow measurements

BACKGROUND AND PURPOSE

CTP imaging in the interventional suite could reduce delays to the start of image-guided interventions and help determine the treatment progress and end point. However, C-arms rotate slower than clinical CT scanners, making CTP challenging. We developed a cerebral CTP protocol for C-arm CBCT and evaluated it in an animal study.

MATERIALS AND METHODS

Five anesthetized swine were imaged by using C-arm CBCT and conventional CT. The C-arm rotates in 4.3 seconds plus a 1.25-second turnaround, compared with 0.5 seconds for clinical CT. Each C-arm scan had 6 continuous bidirectional sweeps. Multiple scans each with a different delay to the start of an aortic arch iodinated contrast injection and a novel image reconstruction algorithm were used to increase temporal resolution. Three different scan sets (consisting of 6, 3, or 2 scans) and 3 injection protocols (3-mL/s 100%, 3-mL/s 67%, and 6-mL/s 50% contrast concentration) were studied. CBF maps for each scan set and injection were generated. The concordance and Pearson correlation coefficients (ρ and r) were calculated to determine the injection providing the best match between the following: the left and right hemispheres, and CT and C-arm CBCT.

RESULTS

The highest ρ and r values (both 0.92) for the left and right hemispheres were obtained by using the 6-mL 50% iodinated contrast concentration injection. The same injection gave the best match for CT and C-arm CBCT for the 6-scan set (ρ = 0.77, r = 0.89). Some of the 3-scan and 2-scan protocols provided matches similar to those in CT.

CONCLUSIONS

This study demonstrated that C-arm CBCT can produce CBF maps that correlate well with those from CTP.

The benefits of on-site cytology with ultrasound-guided fine needle aspiration in a one-stop neck lump clinic

INTRODUCTION

In the National Institute for Health and Clinical Excellence (NICE) guidance on cancer services published in 2004, it was recommended that specialist clinics should be set up for the assessment of patients with neck lumps, structured in a similar way to one-stop breast lump clinics with a cytopathologist present and preferably ultrasound guidance. The aim of this study was to audit the performance of ultrasound-guided fine needle aspiration (FNA) with on-site cytology in a one-stop neck lump clinic at The Royal Liverpool University Hospital.

PATIENTS AND METHODS

Data were collected between November 2008 and May 2009 (7 months). Details of the adequacy rate for the FNA were recorded and whether multiple passes were required. The likely adequacy rate if ultrasound guidance was not available was also calculated.

RESULTS

A total of 274 patients were included in the audit. Of these, 227 (83%) patients required a single pass for adequate diagnostic material. Of the remaining, 45 (16%) required two passes and 2 (1%) required three passes. The overall sample inadequacy rate was 11 of 274 (4%). From these results, it could be predicted that, if immediate cytological evaluation was unavailable, the inadequacy rate would have been 41 of 274 (15%).

CONCLUSIONS

This audit has illustrated the benefits of a one-stop clinic with on-site cytology in providing a rapid diagnostic head and neck cancer service.

The benefits of on-site cytology with ultrasound-guided fine needle aspiration in a one-stop neck lump clinic

INTRODUCTION

In the National Institute for Health and Clinical Excellence (NICE) guidance on cancer services published in 2004, it was recommended that specialist clinics should be set up for the assessment of patients with neck lumps, structured in a similar way to one-stop breast lump clinics with a cytopathologist present and preferably ultrasound guidance. The aim of this study was to audit the performance of ultrasound-guided fine needle aspiration (FNA) with on-site cytology in a one-stop neck lump clinic at The Royal Liverpool University Hospital.

PATIENTS AND METHODS

Data were collected between November 2008 and May 2009 (7 months). Details of the adequacy rate for the FNA were recorded and whether multiple passes were required. The likely adequacy rate if ultrasound guidance was not available was also calculated.

RESULTS

A total of 274 patients were included in the audit. Of these, 227 (83%) patients required a single pass for adequate diagnostic material. Of the remaining, 45 (16%) required two passes and 2 (1%) required three passes. The overall sample inadequacy rate was 11 of 274 (4%). From these results, it could be predicted that, if immediate cytological evaluation was unavailable, the inadequacy rate would have been 41 of 274 (15%).

CONCLUSIONS

This audit has illustrated the benefits of a one-stop clinic with on-site cytology in providing a rapid diagnostic head and neck cancer service.

International guidelines for the diagnosis and management of hereditary haemorrhagic telangiectasia

BACKGROUND

HHT is an autosomal dominant disease with an estimated prevalence of at least 1/5000 which can frequently be complicated by the presence of clinically significant arteriovenous malformations in the brain, lung, gastrointestinal tract and liver. HHT is under-diagnosed and families may be unaware of the available screening and treatment, leading to unnecessary stroke and life-threatening hemorrhage in children and adults.

OBJECTIVE

The goal of this international HHT guidelines process was to develop evidence-informed consensus guidelines regarding the diagnosis of HHT and the prevention of HHT-related complications and treatment of symptomatic disease.

METHODS

The overall guidelines process was developed using the AGREE framework, using a systematic search strategy and literature retrieval with incorporation of expert evidence in a structured consensus process where published literature was lacking. The Guidelines Working Group included experts (clinical and genetic) from eleven countries, in all aspects of HHT, guidelines methodologists, health care workers, health care administrators, HHT clinic staff, medical trainees, patient advocacy representatives and patients with HHT. The Working Group determined clinically relevant questions during the pre-conference process. The literature search was conducted using the OVID MEDLINE database, from 1966 to October 2006. The Working Group subsequently convened at the Guidelines Conference to partake in a structured consensus process using the evidence tables generated from the systematic searches.

RESULTS

The outcome of the conference was the generation of 33 recommendations for the diagnosis and management of HHT, with at least 80% agreement amongst the expert panel for 30 of the 33 recommendations.

Detection and characterization of a glutathione conjugate of a novel copper complex

Glutathione (GSH), an important component of the phase II detoxification system, plays a major role in storage, metabolism and transport of metals across the cell membrane. The role of copper, its metabolism and storage in living systems is not completely understood. Copper plays an important role in a number of physiological processes, e.g. several growth and transcription factors require copper for activity. In the present investigation, we focused on copper (II) (N-2-hydroxyacetophenone) glycinate (CuNG), a novel in vitro and in vivo resistance modifying agent. A conjugate of GSH and CuNG was detected in vivo in mice and was characterized by spectroscopic studies. Based on UV, IR, proton NMR and elemental analyses, the chemical structure of the conjugate was elucidated. By means of atomic absorption data, the distribution and metabolism of CuNG is described.

Susceptibility to seasickness

This paper explains part of the observed variability in passenger illness ratings aboard ships by gender, age and sickness history. Within the framework of a European project, 2840 questionnaires, gathered on several ships operating all over Europe, were analysed. Gender, age and sickness history all had a highly significant effect on seasickness. Furthermore, these effects could be characterized by two fixed parameters describing a general age effect, a third parameter dependent on sickness history and a fourth parameter dependent on gender. Female illness ratings peaked at an age of 11 years, 1.5 times as high as male ratings, which peaked at an age of 21 years. At higher ages, illness ratings decrease to only 20% of their maximum, reducing gender differences to zero. Passengers with a previous history of seasickness rated their illness about two times higher than those who had not felt sick before.