Depression, anxiety, pain and quality of life in people living with chronic hepatitis C: A systematic review and meta-analysis

Objectives: Individuals infected with hepatitis C virus (HCV) can develop extrahepatic conditions which may have a significant impact on life expectancy and quality of life. We conducted a systematic review to assess the causal relationship between HCV and extrahepatic conditions and the impact of HCV upon health-related quality of life of people in the UK. / Methods: HCV advocacy groups identified conditions that they thought most important to research, and the perspectives of various stakeholders informed the scope of the review. A comprehensive literature search of a range of electronic databases and websites was undertaken. Screening, quality assessment and data extraction were conducted using specialist software. The key criterion for inclusion in a synthesis was a study’s testing of the association between HCV and either quality of life or conditions specified as important by advocacy groups: depression, anxiety or painful conditions. Other criteria relating to study populations, measures and matching of study groups were also applied. Two reviewers assessed included studies, with disagreements resolved by a third reviewer where necessary. Studies were assessed for methodological quality using standardised appraisal tools. Metaanalyses were performed. Based on the consistency and sufficiency of research evidence, the findings were graded as strong, promising, tentative or inconclusive. / Results: 71 studies were included in the review’s syntheses. All studies were judged to be at a moderate or high risk of bias. Only two UK studies met our inclusion criteria. / Quality of life: Evidence from 22 studies indicates that people with HCV have worse quality of life than ‘general’ or ‘healthy’ populations; meta-analysis of nine studies indicated\ud that the physical (PCS) and mental health (MCS) domains of quality of life on the Health-Related Quality of Life Scale were both statistically and clinically worse among HCV-infected people (PCS: MD 5.54, 95% CI 3.73-7.35, MCS: MD 3.81, 95% CI 1.97-5.64). Evidence from seven included studies suggests that people co-infected with HCV and HIV have worse quality of life than individuals with HIV only; metaanalysis of five studies indicated that both the physical and mental health domains of quality of life were significantly worse among people who were co-infected (PCS: MD 2.57, 95% CI 1.08-4.06, MCS: MD 1.88, 95% CI 0.06-3.69). / Depression and anxiety: Evidence from 22 studies indicates that depression and anxiety are more severe, and depression is more common among people with HCV compared to those without it. Meta-analysis of 12 studies identified the severity of depression in people with HCV to be significantly greater than in those without HCV (Mean difference 0.98, 95% CI 0.43-1.53). Meta-analysis of nine studies identified the severity of clinical anxiety to be significantly greater among people with HCV (Mean difference 0.47, 95% CI 0.09-0.86). Meta-analysis of seven studies identified participants with HCV to be approximately three times more likely to be depressed compared to those without HCV (OR 2.77, 95% CI 1.62-4.74). No statistically significant evidence that anxiety is more common among people with HCV was found. / Pain: Evidence was appraised from 26 studies on painful conditions. A meta-analysis of four studies indicates that people with HCV are 17% more likely to suffer from arthralgia than those without HCV (RR 1.17, 95% CI 1.04-1.31). A meta-analysis of five studies suggested that people with HCV are significantly more likely to suffer from fibromyalgia; key differences across the studies in terms of the health status (co-morbidities) of HCV patients and comparison groups mean it is not possible to quantify the increased risk attributable to HCV. Other studies, including those on arthritis, were not amenable to meta-analysis. / Conclusions: Evidence suggests an association between HCV infection and depression, anxiety, fibromyalgia, arthralgia and health-related quality of life. However, the evidence was graded as ‘promising’ or ‘tentative’ rather than ‘strong’. More high-quality research on the association between HCV and these conditions is needed

Polarization squeezing of intense pulses with a fiber Sagnac interferometer

We report on the generation of polarization squeezing of intense, short light pulses using an asymmetric fiber Sagnac interferometer. The Kerr nonlinearity of the fiber is exploited to produce independent amplitude squeezed pulses. The polarization squeezing properties of spatially overlapped amplitude squeezed and coherent states are discussed. The experimental results for a single amplitude squeezed beam are compared to the case of two phase-matched, spatially overlapped amplitude squeezed pulses. For the latter, noise variances of -3.4dB below shot noise in the S0 and the S1 and of -2.8dB in the S2 Stokes parameters were observed, which is comparable to the input squeezing magnitude. Polarization squeezing, that is squeezing relative to a corresponding polarization minimum uncertainty state, was generated in S1.Comment: v4: 2 small typos corrected v3: misc problems with Tex surmounted - mysteriously missing text returned to results - vol# for Korolkova et al. PRA v2: was a spelling change in author lis

A pulsed source of continuous variable polarization entanglement

We have experimentally demonstrated polarization entanglement using continuous variables in an ultra-short pulsed laser system at telecommunication wavelengths. Exploiting the Kerr-nonlinearity of a glass fibre we generated a polarization squeezed pulse with S2 the only non-zero Stokes parameter thus S1 and S3 being the conjugate pair. Polarization entanglement was generated by interference of the polarization squeezed field with a vacuum on a 50:50 beam splitter. The two resultant beams exhibit strong quantum noise correlations in S1 and S3. The sum noise signal of S3 was at the respective shot noise level and the difference noise signal of S1 fell 2.9dB below this value

Rhizosphere bacteria are more strongly related to plant root traits than fungi in temperate montane forests: insights from closed and open forest patches along an elevational gradient

Heterogeneous canopies in temperate montane forests affect microclimate and soil characteristics, with important effects on soil microbial communities and related processes. Here, we studied the interactions between plant root traits and soil bacterial and fungal communities in closed forest and gaps in a mixed forest along an elevational gradient in the French Alps (1400, 1700 and 2000 m). Samples were separated into three fractions (plant root endosphere, rhizosphere and bulk soil), to further investigate the influence of plant zones on microbial communities. Bacterial (16S) and fungal (ITS) biodiversity was determined using high throughput sequencing, along with standard measures of soil, litter and root traits. We found that (i) microbial community diversity was higher in gaps than in closed forest because of increased root trait diversity and density; (ii) open versus closed forest patches affected phylogenetic dispersion despite differences in elevations with phylogenetic clustering in closed forest; (iii) the interaction between root traits and microbial communities was stronger for rhizosphere and endosphere compartments than for bulk soil and (iv) bacterial community composition was better explained by root traits than for fungi. Our findings highlight the importance of open gaps versus closed forest patches and associated root traits affecting microbial community structure, particularly for bacterial assemblages that exhibited a stronger interaction with root traits than for fungi

Interacting effects of land use type, soil microbes and plant traits on aggregate stability

Soil aggregates are critical to soil functionality, but there remain many uncertainties with respect to the role of biotic factors in forming aggregates. Understanding the interacting effects of soil, land use type, vegetation and microbial communities is a major challenge that needs assessment in both field and controlled laboratory conditions, as well as in bulk and rhizosphere soils. To address these effects and their feedbacks, we first examined the influence of soil, root and litter characteristics along a land use gradient (ancient woodland, secondary woodland, grassland, pasture and arable land) on microbial community structure (in both bulk and rhizosphere soil), as well as on aggregate stability. Then, we performed an inoculation experiment where we extracted soil columns from the arable and secondary woodland and used a third unstructured loamy soil as a control. We sterilized these three soils to remove microbial communities, and then either inoculated the tops of sterilized soil columns with soil from the secondary woodland or the arable field sites. Control columns of all soil types were not inoculated. In a fully-crossed design, we planted two species possessing distinct root system morphological traits: Brachypodium sylvaticum (fibrous system with many thin and fine roots) and Urtica dioica (taproot system with few fine roots). After four months, microbial communities (in bulk and rhizospheric soil) and aggregate stability were measured, along with root traits. In both the field and laboratory experiments, bacterial (16S) and fungal (ITS) biodiversity was determined using high throughput sequencing. In the field study we found that: i) there were strong relationships between aggregate stability and microbial community composition that were driven by land use, ii) the relationship between aggregate stability along the land use gradient and the trophic nature of bacterial communities was not significant, but that certain soil, root and litter parameters shaped bacterial phyla, with oligotrophic bacteria conditioned by the rhizosphere niche, and copiotrophic phyla more dependent on bulk soil conditions, iii) land use gradient (from woodland to arable), reduced the relative abundance of saprotrophic and ectomycorrhizal fungi with an increase in the relative abundance of Ascomycota and a reduction in the relative abundance of Basidiomycota. In the laboratory experiment we found that: i) the inoculation of sterilized soils with soils from the field significantly increased aggregate stability in control soil that was initially poorly structured, ii) the effects of inoculation on aggregate stability were similar when either secondary woodland or arable soils were used as inoculums and iii) these effects were affected significantly by root length density. Our results show that microbial communities influence soil structure and that bacterial communities are intimately associated to rhizospheric conditions and root traits (of which root length density was the most pertinent)

Percutaneous suction and irrigation for the treatment of recalcitrant pyogenic spondylodiscitis.

The primary management of pyogenic spondylodiscitis is conservative. Once the causative organism has been identified, by blood culture or biopsy, administration of appropriate intravenous antibiotics is started. Occasionally patients do not respond to antibiotics and surgical irrigation and debridement is needed. The treatment of these cases is challenging and controversial. Furthermore, many affected patients have significant comorbidities often precluding more extensive surgical intervention. The aim of this study is to describe early results of a novel, minimally invasive percutaneous technique for disc irrigation and debridement in pyogenic spondylodiscitis.This article is freely available via Open Access. Click on the Additional Link above to access the full-text via the publisher's sit

A leaky umbrella has little value: evidence clearly indicates the serotonin system is implicated in depression.

A recent “umbrella” review examined various biomarkers relating to the serotonin system, and concluded there was no consistent evidence implicating serotonin in the pathophysiology of depression. We present reasons for why this conclusion is overstated, including methodological weaknesses in the review process, selective reporting of data, over-simplification, and errors in the interpretation of neuropsychopharmacological findings. We use the examples of tryptophan depletion and serotonergic molecular imaging, the two research areas most relevant to the investigation of serotonin, to illustrate this

A leaky umbrella has little value:evidence clearly indicates the serotonin system is implicated in depression

A recent “umbrella” review examined various biomarkers relating to the serotonin system, and concluded there was no consistent evidence implicating serotonin in the pathophysiology of depression. We present reasons for why this conclusion is overstated, including methodological weaknesses in the review process, selective reporting of data, over-simplification, and errors in the interpretation of neuropsychopharmacological findings. We use the examples of tryptophan depletion and serotonergic molecular imaging, the two research areas most relevant to the investigation of serotonin, to illustrate this