A luminous fast radio burst that probes the Universe at redshift 1.

Fast radio bursts (FRBs) are millisecond-duration pulses of radio emission originating from extragalactic distances. Radio dispersion is imparted on each burst by intervening plasma, mostly located in the intergalactic medium. In this work, we observe the burst FRB 20220610A and localize it to a morphologically complex host galaxy system at redshift 1.016 ± 0.002. The burst redshift and dispersion measure are consistent with passage through a substantial column of plasma in the intergalactic medium and extend the relationship between those quantities measured at lower redshift. The burst shows evidence for passage through additional turbulent magnetized plasma, potentially associated with the host galaxy. We use the burst energy of 2 × 1042 erg to revise the empirical maximum energy of an FRB.

A census of baryons in the Universe from localized fast radio bursts.

More than three-quarters of the baryonic content of the Universe resides in a highly diffuse state that is difficult to detect, with only a small fraction directly observed in galaxies and galaxy clusters1,2. Censuses of the nearby Universe have used absorption line spectroscopy3,4 to observe the 'invisible' baryons, but these measurements rely on large and uncertain corrections and are insensitive to most of the Universe's volume and probably most of its mass. In particular, quasar spectroscopy is sensitive either to the very small amounts of hydrogen that exist in the atomic state, or to highly ionized and enriched gas4-6 in denser regions near galaxies7. Other techniques to observe these invisible baryons also have limitations; Sunyaev-Zel'dovich analyses8,9 can provide evidence from gas within filamentary structures, and studies of X-ray emission are most sensitive to gas near galaxy clusters9,10. Here we report a measurement of the baryon content of the Universe using the dispersion of a sample of localized fast radio bursts; this technique determines the electron column density along each line of sight and accounts for every ionized baryon11-13. We augment the sample of reported arcsecond-localized14-18 fast radio bursts with four new localizations in host galaxies that have measured redshifts of 0.291, 0.118, 0.378 and 0.522. This completes a sample sufficiently large to account for dispersion variations along the lines of sight and in the host-galaxy environments11, and we derive a cosmic baryon density of [Formula: see text] (95 per cent confidence; h70 = H0/(70 km s-1 Mpc-1) and H0 is Hubble's constant). This independent measurement is consistent with values derived from the cosmic microwave background and from Big Bang nucleosynthesis19,20.

A single fast radio burst localized to a massive galaxy at cosmological distance.

Fast radio bursts (FRBs) are brief radio emissions from distant astronomical sources. Some are known to repeat, but most are single bursts. Nonrepeating FRB observations have had insufficient positional accuracy to localize them to an individual host galaxy. We report the interferometric localization of the single-pulse FRB 180924 to a position 4 kiloparsecs from the center of a luminous galaxy at redshift 0.3214. The burst has not been observed to repeat. The properties of the burst and its host are markedly different from those of the only other accurately localized FRB source. The integrated electron column density along the line of sight closely matches models of the intergalactic medium, indicating that some FRBs are clean probes of the baryonic component of the cosmic web.

Short-term changes observed in multiparametric liver MRI following therapy with direct-acting antivirals in chronic hepatitis C virus patients.

METHODS: We applied multiparametric MRI to assess changes in liver composition, perfusion and blood flow in 17 patients before direct-acting antiviral (DAA) therapy and after treatment completion (within 12 weeks of last DAA tablet swallowed). RESULTS: We observed changes in hepatic composition indicated by a reduction in both liver longitudinal relaxation time (T1, 35 ± 4 ms), transverse relaxation time (T2, 2.5 ± 0.8 ms; T2* 3.0 ± 0.7 ms), and liver perfusion (28.1 ± 19.7 ml/100 g/min) which we suggest are linked to reduced pro-inflammatory milieu, including interstitial oedema, within the liver. No changes were observed in liver or spleen blood flow, splenic perfusion, or superior mesenteric artery blood flow. CONCLUSION: For the first time, our study has shown that treatment of HCV with DAAs in patients with cirrhosis leads to an acute reduction in liver T1, T2 and T2* and an increase in liver perfusion measured using MR parameters. The ability of MRI to characterise changes in the angio-architecture of patients with cirrhosis after intervention in the short term will enhance our understanding of the natural history of regression of liver disease and potentially influence clinical decision algorithms. KEY POINTS: • DAAs have revolutionised the treatment of hepatitis C and achieve sustained virological response in over 95% of patients, even with liver cirrhosis. • Currently available non-invasive measures of liver fibrosis are not accurate after HCV treatment with DAAs, this prospective single-centre study has shown that MRI can sensitively measure changes within the liver, which could reflect the reduction in inflammation with viral clearance. • The ability of MRI to characterise changes in structural and haemodynamic MRI measures in the liver after intervention will enhance our understanding of the progression/regression of liver disease and could potentially influence clinical decision algorithms.

Obesity and type 2 diabetes are important risk factors underlying previously undiagnosed cirrhosis in general practice: a cross-sectional study using transient elastography.

BACKGROUND: Rising cirrhosis incidence and mortality in the United Kingdom has been attributed predominantly to excess alcohol consumption. However, metabolic risk factors such as Type 2 diabetes and obesity may also be important. AIM: To screen at-risk individuals in general practice for undetected cirrhosis using transient elastography and study the risk factors underlying these cases. METHODS: The study was undertaken in 4 general practices (adult patient population 20 868) between February 2012 and September 2014. Patients with defined risk factors for chronic liver disease (hazardous alcohol use and/or Type 2 diabetes) were identified from the General Practice electronic records and invited for transient elastography. Elevated liver stiffness was defined as ≥8 kPa. Cirrhosis was confirmed by established histological, radiological and biochemical methods. RESULTS: Two thousand three hundred and sixty eight patients were invited for transient elastography and 899/919 who attended (97.8%) had valid measurements. Of these 230 patients had elevated liver stiffness (25.6%) and 27 had cirrhosis (2.9%). Risk factors for new cirrhosis diagnoses were obesity and/or Type 2 diabetes in 16 patients (59.3%), alcohol alone in 3 (11.1%) and both alcohol and obesity and/or diabetes in eight (29.6%). Presence of cirrhosis was significantly increased in obese patients with Type 2 diabetes or hazardous alcohol use compared to non-obese (odds ratio 9.4 [95% CI 2.2-40.9] and 5.6 [95% CI 1.6-19.7] respectively). CONCLUSIONS: The number of new cases of cirrhosis diagnosed clearly demonstrates that existing estimates of prevalence are likely to be gross underestimates. Obesity was an important risk factor for cirrhosis within both alcohol users and diabetics.

Prevention of progression to cirrhosis in hepatitis C with fibrosis: effectiveness and cost effectiveness of sequential therapy with new direct-acting anti-virals.

BACKGROUND: The new direct-acting anti-virals (DAAs) for hepatitis C virus (HCV) infection offer higher cure rates, but at a much higher cost than the standard interferon-based treatments. AIM: To identify the cost-effective treatment for patients with HCV infection with F3 liver fibrosis who are at high risk of progression to cirrhosis. METHODS: A decision-analytic Markov model compared the health benefits and costs of all currently licensed treatments as single treatments and in sequential therapy of up to three lines. Costs were expressed in pound sterling from the perspective of the UK National Health Service. Health benefits were expressed in quality-adjusted life years. RESULTS: Treatment before progression to cirrhosis always offers the most health benefits for the least costs. Sequential therapy with multiple treatment lines cures over 89% of patients across all HCV genotypes while ensuring a cost-effective use of resources. Cost-effective regimes for HCV genotype 1 patients include first-line oral therapy with sofosbuvir-ledipasvir while peginterferon continues to have a role in other genotypes. CONCLUSIONS: The cost-effective treatment for HCV can be established using decision analytic modelling comparing single and sequential therapies. Sequential therapy with DAAs is effective and cost-effective in HCV patients with F3 fibrosis. This information is of significant benefit to health care providers with budget limitations and provides a sound scientific basis for drug treatment choices.

Review article: 2014 UK consensus guidelines - hepatitis C management and direct-acting anti-viral therapy.

BACKGROUND: Therapeutic options for the management of hepatitis C virus (HCV) infection have evolved rapidly over the past two decades, with a consequent improvement in cure rates. Novel therapeutic agents are an area of great interest in the research community, with a number of these agents showing promise in the clinical setting. AIMS: To assess and present the available evidence for the use of novel therapeutic agents for the treatment of HCV, updating previous guidelines. METHODS: All Phase 2 and 3 studies, as well as abstract presentations from international Hepatology meetings were identified and reviewed for suitable inclusion, based on studies of new therapies in HCV. Treatment-naïve and experienced individuals, as well as cirrhotic and co-infected individuals were included. RESULTS: Sofosbuvir, simeprevir and faldaprevir, along with pegylated interferon and ribavirin, have a role in the treatment of chronic HCV infection. The precise regimens are largely dependent on the patient characteristics, patient and physician preferences, and cost implication. CONCLUSIONS: Therapies for chronic HCV have evolved dramatically in recent years. Interferon-free regimens are now possible without compromise in the rate of sustained viral response. The decision as to which regimen is most appropriate is multifactorial, and based on efficacy, safety and cost.

Historical epidemiology of hepatitis C virus (HCV) in selected countries.

Chronic infection with hepatitis C virus (HCV) is a leading indicator for liver disease. New treatment options are becoming available, and there is a need to characterize the epidemiology and disease burden of HCV. Data for prevalence, viremia, genotype, diagnosis and treatment were obtained through literature searches and expert consensus for 16 countries. For some countries, data from centralized registries were used to estimate diagnosis and treatment rates. Data for the number of liver transplants and the proportion attributable to HCV were obtained from centralized databases. Viremic prevalence estimates varied widely between countries, ranging from 0.3% in Austria, England and Germany to 8.5% in Egypt. The largest viremic populations were in Egypt, with 6,358,000 cases in 2008 and Brazil with 2,106,000 cases in 2007. The age distribution of cases differed between countries. In most countries, prevalence rates were higher among males, reflecting higher rates of injection drug use. Diagnosis, treatment and transplant levels also differed considerably between countries. Reliable estimates characterizing HCV-infected populations are critical for addressing HCV-related morbidity and mortality. There is a need to quantify the burden of chronic HCV infection at the national level.

UK consensus guidelines for the use of the protease inhibitors boceprevir and telaprevir in genotype 1 chronic hepatitis C infected patients.

BACKGROUND: The nonstructural 3 serine protease inhibitors (PIs), boceprevir and telaprevir, represent the first in a new generation of directly acting antivirals against genotype 1 hepatitis C (HCV) infection. When used in combination with pegylated interferon and ribavirin, these drugs greatly improve sustained virological response rates in both treatment-naïve patients and patients who have had previous virological failure on treatment. However, the addition of these new agents will increase the complexity of therapeutic regimens, the rates of side-effects and costs. AIMS: To review concisely the current evidence and to suggest current best practice, for the use of telaprevir and boceprevir in the management of chronic genotype 1 HCV infection. METHODS: These guidelines for the use of boceprevir and telaprevir have been formulated following extensive review of the current literature, are based on the consensus opinion of a panel of national experts, and have been openly discussed and debated at a national meeting of HCV care providers. RESULTS: We have made recommendations on a number of the key practical issues facing HCV care providers: (i) Which patients to treat?; (ii) Standards for the provision of care; (iii) Pre-treatment considerations; (iv) Which treatment regimens to use?; (v) Stopping rules; and (vi) Management of adverse effects. Finally, we have produced suggested algorithms for the assessment and treatment of these patients. CONCLUSIONS: These UK Consensus guidelines indicate the current best practice for the use of boceprevir and telaprevir in the management of genotype 1 chronic HCV infection.

A complex multi-notch astronomical filter to suppress the bright infrared sky.

A long-standing and profound problem in astronomy is the difficulty in obtaining deep near-infrared observations due to the extreme brightness and variability of the night sky at these wavelengths. A solution to this problem is crucial if we are to obtain the deepest possible observations of the early Universe, as redshifted starlight from distant galaxies appears at these wavelengths. The atmospheric emission between 1,000 and 1,800 nm arises almost entirely from a forest of extremely bright, very narrow hydroxyl emission lines that varies on timescales of minutes. The astronomical community has long envisaged the prospect of selectively removing these lines, while retaining high throughput between them. Here we demonstrate such a filter for the first time, presenting results from the first on-sky tests. Its use on current 8 m telescopes and future 30 m telescopes will open up many new research avenues in the years to come.

Effectiveness of a nurse-led alcohol liaison service in a secondary care medical unit.

Alcohol misuse is a common reason for hospital admission. While there is considerable evidence from other areas that provision of specialised alcohol services can reduce alcohol intake, there is currently less evidence for medical departments in an acute hospital setting. Nottingham hospitals initiated such a service in 2002-3 based around two nurse specialists who provided input to inpatients with alcohol-related physical disease and provided links to community-based services for alcohol misuse. This service assessed 3632 patients over five years and has seen a reduction in hospital admissions, violent incidents against staff and primary care attendances. It is believed that this model of care is an effective means of intervening in people with alcohol-related problems.

Autoantibodies in chronic hepatitis C virus infection and their association with disease profile.

Autoantibodies are commonly detected in chronic hepatitis C (HCV) but their significance remains uncertain. We assessed the prevalence of anti-nuclear (ANA) and anti-smooth muscle (ASM) antibodies within a cohort of 963 treatment-naïve HCV patients. We also assessed for differences between autoantibody-positive and autoantibody-negative patients in demographics, markers of disease activity and response to anti-viral treatment. One hundred and seventy-two patients (17.9%) had at least one autoantibody, of which were 104 (10.8%) ASM, 54 (5.6%) ANA and 14 (1.5%) positive for both. Autoantibody-positive patients were older (43 vs 39 years, P = 0.001) caused by an age-related increase in ANA (but not ASM). There were no differences in gender, alcohol intake, ethnicity or viral genotype. The presence of autoantibodies, and specifically ASM, was associated with an increase in interface hepatitis score amongst men (1.1 vs 0.8, P = 0.005) but no difference in other necroinflammatory measures, liver function tests or immunoglobulins (Ig). There was no difference in initial fibrosis stage or rate of fibrosis progression. Autoantibodies did not affect response to anti-viral treatment. We conclude that autoantibodies are frequent in HCV infection. Anti-nuclear antibodies increase with age, whereas ASM antibodies are associated with interface hepatitis in men. Neither autoantibody carries increased risk of fibrosis progression or failure of therapy.

Response rates to combination therapy for chronic HCV infection in a clinical setting and derivation of probability tables for individual patient management.

Evidence for efficacy of established treatment guidelines for chronic hepatitis C virus (HCV) disease is based on multinational randomized controlled trials (RCTs). Strategies for managing HCV, however, require an assessment of the effectiveness of intervention in routine clinical practice. We report the outcomes of combination therapy in a large cohort of HCV-infected individuals in the UK. A total of 347 (113 genotype 1, 234 genotype non-1) patients were treated with pegylated interferon and ribavirin according to current guidelines. Forty-two (37.2%) of those with genotype 1 infection and 164 (70.1%) with genotype non-1 infection achieved sustained viral response (SVR). Thirty-nine (11%) patients withdrew from treatment. In addition to viral genotype, factors predictive of a response to therapy were age at start of treatment and disease stage on pretreatment liver biopsy. Multivariate regression analysis demonstrated that the effects of age [odds ratio 0.5; 95% confidence interval (0.31-0.82) per 10-year increment (P = 0.006)] were confined to genotype 1 disease. In order to further inform the management of the individual patient, a multivariate logistic model was used to predict the probability of SVR for subgroups defined by disease stage, genotype and age at commencement of therapy. This model revealed striking differences in predicted response rates between subgroups and provided a strong rationale for early treatment, particularly for those with genotype 1 disease. Our study demonstrates that results comparable with those of RCTs can be achieved in clinical practice, and suggests that prediction of response rates based on probability modelling will provide a valuable adjunct to individual patient management.

Severe fibrosis in hepatitis C virus-infected patients is associated with increased activity of the mannan-binding lectin (MBL)/MBL-associated serine protease 1 (MASP-1) complex.

Mannan-binding lectin (MBL) binds microorganisms via interactions with glycans on the target surface. Bound MBL subsequently activates MBL-associated serine protease proenzymes (MASPs). A role for MBL in hepatitis C virus (HCV) infection had been indicated by previous studies examining MBL levels and polymorphisms in relation to disease progression and response to treatment. We undertook this study to investigate a possible relationship between disease progression and functional MBL/MASP-1 complex activity. A functional assay for MBL/MASP-1 complex activity was employed to examine serum samples from patients with chronic HCV infection, non-HCV liver disease and healthy controls. Intrapatient consistency of MBL/MASP-1 complex activity levels was assessed in sequential samples from a subgroup of patients. Median values of MBL/MASP-1 complex activity were higher in sera from patients with liver disease compared with healthy controls. MBL/MASP-1 complex activity levels correlate with severity of fibrosis after adjusting for confounding factors (P = 0.003). MBL/MASP-1 complex activity was associated more significantly with fibrosis than was MBL concentration. The potential role of MBL/MASP-1 complex activity in disease progression is worthy of further study to investigate possible mechanistic links.

Clinical pathways for patients with newly diagnosed hepatitis C - what actually happens.

Management of hepatitis C virus (HCV)-infected individuals requires referral to specialist care. To determine whether patients newly diagnosed as anti-HCV positive are appropriately referred for further investigation and management, and if not, to determine why not. We studied patients tested for antibodies to HCV by Nottingham Public Health Laboratory in a 2-year period (2000-2002). The progress of newly diagnosed anti-HCV positive patients into specialist clinics for further management was documented. For patients not referred for specialist care, a questionnaire was sent to the clinician requesting the initial anti-HCV test, to identify reasons for nonreferral. Eleven thousand one hundred and seventy-seven patients were tested for anti-HCV. Two hundred and fifty-six (2.3%) were newly diagnosed as being anti-HCV positive. Two per cent of samples sent from primary care were anti-HCV positive, compared to 18.8, 18.9 and 1.3% sent from prison, drug and alcohol units, and secondary care, respectively. About 64.3% of positive patients diagnosed in primary care were referred to specialist care, compared to 18.4, 42.4 and 62.6% of patients diagnosed in the other three settings. One hundred and twenty-five (49%) newly diagnosed patients were referred appropriately for further management. 68 of these attended clinic, 45 underwent liver biopsy and 26 (10%) began treatment. One hundred and thirty-one patients (51%) were not referred. In 54 cases, there was no evidence that the anti-HCV positive result reached the patient. In 15, referral was considered but rejected, and 20 patients were referred to non-HCV-specialists (their general practitioners or to genito-urinary medicine). Hence less than 50% of newly diagnosed anti-HCV positive patients are referred to an appropriate clinic for further investigation and management. Reasons for this are multifarious and complex, reflecting both systems failure and patient choice. Unless these are understood and addressed, the Department of Health Hepatitis C Strategy (2002) and Action Plan for England (2004) will fail to achieve their intended objectives.

Fracture risk of women with primary biliary cirrhosis: no increase compared with general population controls.

AIM: Patients with primary biliary cirrhosis may be at increased risk of osteoporosis but to what extent this is reflected in an increased fracture risk is unknown. We have enquired about the fracture experience of female primary biliary cirrhosis patients compared with sex- and age-matched controls. METHODS: Patients aged 30-75 with primary biliary cirrhosis and age-matched controls were sent a postal questionnaire asking about their fracture history and details of risk factors for osteoporosis. RESULTS: 85 eligible patients with primary biliary cirrhosis and 116 controls responded. Forty-one per cent of patients with primary biliary cirrhosis and 30% of controls reported ever having had a fracture odds ratio 1.5 (95% confidence interval: 0.80-2.89). Twenty-eight per cent of primary biliary cirrhosis patients and 23.3% of controls reported a fracture after the age of 30, odds ratio 1.2 (95% confidence interval: 0.57-2.56), and 14.1% of primary biliary cirrhosis patients and 12.1% of controls reported a low impact fracture of the long bones or of the vertebrae odds ratio 1.0 (95% confidence interval: 0.31-2.68). CONCLUSIONS: No overall increased fracture risk in patients with primary biliary cirrhosis was observed. As a group, unselected patients with primary biliary cirrhosis do not represent a population at particularly high risk of osteoporotic fracture and thus targeting them for osteoporosis screening and treatment is not justified. Further work investigating subgroups of patients with primary biliary cirrhosis at potentially high risk of osteoporosis, such as those with advanced disease or severe cholestasis is required.

Improving diagnostic yield of biliary brushings cytology for pancreatic cancer and cholangiocarcinoma.

Biliary brushings are currently the best accepted method to obtain a cytological diagnosis of pancreatic cancer or cholangiocarcinoma. The technique has good specificity but poor sensitivity. Two dedicated pathologists reviewed 137 consecutive biliary brushings from 127 patients between February 1997 and February 2000. The ultimate diagnosis was determined by review of radiology, operative diagnosis and patient outcome. The sensitivity, specificity, positive predictive value and negative predictive value of the original results and the review results were calculated and compared. Additional diagnostic categories 'suspicious' and 'atypical possibly benign' were included on review. After review, the sensitivity improved from 49.4% to 89.0% and the specificity remained 100%. The use of the additional diagnostic category 'suspicious' increased the sensitivity to 90.4%, at the expense of a fall of the specificity to 66.7%. We conclude that review by two dedicated pathologists and additional diagnostic categories can improve the diagnostic accuracy of biliary brushings.

Progression of hepatic fibrosis in patients with hepatitis C: a prospective repeat liver biopsy study.

BACKGROUND: The natural history of hepatitis C virus (HCV) infection remains uncertain. Previous data concerning rates of progression are from studies using estimated dates of infection and single liver biopsy scores. We prospectively studied the rate of progression of fibrosis in HCV infected patients by repeat liver biopsies without intervening treatment. PATIENTS: We studied 214 HCV infected patients (126 male; median age 36 years (range 5-8)) with predominantly mild liver disease who were prospectively followed without treatment and assessed for risk factors for progression of liver disease. Interbiopsy interval was a median of 2.5 years. Paired biopsies from the same patient were scored by the same pathologist. RESULTS: Seventy of 219 (33%) patients showed progression of at least 1 fibrosis point in the Ishak score; 23 progressed at least 2 points. Independent predictors of progression were age at first biopsy and any fibrosis on first biopsy. Factors not associated with progression were: necroinflammation, duration of infection, alcohol consumption, alanine aminotransferase levels, current or past hepatitis B virus infection, ferritin, HCV genotype, and steatosis or iron deposition in the initial biopsy. CONCLUSIONS: One third of patients with predominantly mild hepatitis C showed significant fibrosis progression over a median period of 30 months. Histologically, mild hepatitis C is a progressive disease. The overall rate of fibrosis progression in patients with hepatitis C was low but increased in patients who were older or had fibrosis on their index biopsy. These data suggest that HCV infection will place an increasing burden on health care services in the next 20 years.

A pilot study to investigate the use of oxpentifylline (pentoxifylline) and thalidomide in portal hypertension secondary to alcoholic cirrhosis.

BACKGROUND: Tumour necrosis factor-alpha is thought to be important in the pathogenesis of portal hypertension. Oxpentifylline (pentoxifylline) and thalidomide inhibit endotoxin-induced tumour necrosis factor-alpha production in vitro. AIMS: To assess the toxicity of oxpentifylline (pentoxifylline) and thalidomide in cirrhosis and their effect on the hepatic venous pressure gradient and tumour necrosis factor-alpha production. METHODS: In an open-label pilot study, 20 abstinent patients with stable alcoholic cirrhosis and oesophageal varices were recruited; 12 patients completed haemodynamic measurements before and after treatment with oxpentifylline (pentoxifylline) 1800 mg (n=6) or thalidomide 200 mg (n=6) daily for 2 weeks. Tumour necrosis factor-alpha production was assessed in ex vivo monocyte cultures stimulated with endotoxin. RESULTS: Thalidomide reduced the hepatic venous pressure gradient from 19.7 mmHg (9.3-23.5 mmHg) to 12.2 mmHg (4.7-19.5 mmHg) (P=0.03) without reducing the hepatic blood flow or altering systemic haemodynamic parameters. Thalidomide reduced ex vivo tumour necrosis factor-alpha production by approximately 50%. Oxpentifylline (pentoxifylline) had no significant effect on any of the parameters measured. Side-effects led to dose reduction or treatment withdrawal in 40% of patients. CONCLUSION: Thalidomide, but not oxpentifylline (pentoxifylline), reduces the hepatic venous pressure gradient in stable alcoholic cirrhotics, an effect that may be mediated by the inhibition of tumour necrosis factor-alpha production. The role of tumour necrosis factor-alpha inhibitory drugs in the therapy of portal hypertension should be investigated in a randomized controlled trial.