419 research outputs found
Immunomodulating effects of the anti-viral agent Silibinin in liver transplant patients with HCV recurrence
Background: Silibinin has been shown to have anti-HCV activity and immune-modulating properties by regulating dendritic cell (DC) function. DCs are antigen-presenting cells that, together with regulatory T cells (Treg), play a pivotal role in controlling alloimmune, as well as anti-HCV immune responses. Methods: Twelve liver transplant patients with HCV recurrence received iv infusion of Silibinin (iv-SIL) for 14 consecutive days. Using flow cytometry, before and at the end of treatment, we determined the frequencies of circulating myeloid (m) and plasmacytoid (p) DC and Treg and the expression of costimulatory/coregulatory molecules by the DC subsets and Treg. Statistical analysis was performed using the paired Student's t test and Pearson correlation test. Results: After iv-SIL treatment, we observed an elevated plasmacytoid dendritic cell (pDC)/myeloid dendritic cell (mDC) ratio, while pDC displayed lower HLA-DR and higher immunoglobulin-like transcript 4 (ILT4), CD39, and HLA-G expression compared to the pretreatment baseline. In addition, after iv-SIL, mDC showed increased inducible costimulator ligand (ICOSL) expression. No changes were detected in Treg frequency or programed death (PD)-1 expression by these cells. Moreover, several correlations between DC/Treg markers and clinical parameters were detected. Conclusions: This descriptive study, in liver transplant patients with HCV recurrence, reveals the impact of iv-SIL on DC and Treg. The changes observed in circulating pDC and mDC that have previously been associated with tolerogenic conditions shed new light on how iv-SIL may regulate anti-viral and alloimmunity. We have also observed multiple clinical correlations that could improve the clinical management of liver transplant patients and that deserve further analysis
Characterization of Nucleotide Misincorporation Patterns in the Iceman's Mitochondrial DNA
BACKGROUND: The degradation of DNA represents one of the main issues in the genetic analysis of archeological specimens. In the recent years, a particular kind of post-mortem DNA modification giving rise to nucleotide misincorporation ("miscoding lesions") has been the object of extensive investigations. METHODOLOGY/PRINCIPAL FINDINGS: To improve our knowledge regarding the nature and incidence of ancient DNA nucleotide misincorporations, we have utilized 6,859 (629,975 bp) mitochondrial (mt) DNA sequences obtained from the 5,350-5,100-years-old, freeze-desiccated human mummy popularly known as the Tyrolean Iceman or Otzi. To generate the sequences, we have applied a mixed PCR/pyrosequencing procedure allowing one to obtain a particularly high sequence coverage. As a control, we have produced further 8,982 (805,155 bp) mtDNA sequences from a contemporary specimen using the same system and starting from the same template copy number of the ancient sample. From the analysis of the nucleotide misincorporation rate in ancient, modern, and putative contaminant sequences, we observed that the rate of misincorporation is significantly lower in modern and putative contaminant sequence datasets than in ancient sequences. In contrast, type 2 transitions represent the vast majority (85%) of the observed nucleotide misincorporations in ancient sequences. CONCLUSIONS/SIGNIFICANCE: This study provides a further contribution to the knowledge of nucleotide misincorporation patterns in DNA sequences obtained from freeze-preserved archeological specimens. In the Iceman system, ancient sequences can be clearly distinguished from contaminants on the basis of nucleotide misincorporation rates. This observation confirms a previous identification of the ancient mummy sequences made on a purely phylogenetical basis. The present investigation provides further indication that the majority of ancient DNA damage is reflected by type 2 (cytosine-->thymine/guanine-->adenine) transitions and that type 1 transitions are essentially PCR artifacts
Chronic widespread musculoskeletal pain, fatigue, depression and disordered sleep in chronic post-SARS syndrome; a case-controlled study
<p>Abstract</p> <p>Background</p> <p>The long term adverse effects of Severe Acute Respiratory Syndrome (SARS), a viral disease, are poorly understood.</p> <p>Methods</p> <p>Sleep physiology, somatic and mood symptoms of 22 Toronto subjects, 21 of whom were healthcare workers, (19 females, 3 males, mean age 46.29 yrs.+/- 11.02) who remained unable to return to their former occupation (mean 19.8 months, range: 13 to 36 months following SARS) were compared to 7 healthy female subjects. Because of their clinical similarities to patients with fibromyalgia syndrome (FMS) these post-SARS subjects were similarly compared to 21 drug free female patients, (mean age 42.4 +/- 11.8 yrs.) who fulfilled criteria for fibromyalgia.</p> <p>Results</p> <p>Chronic post-SARS is characterized by persistent fatigue, diffuse myalgia, weakness, depression, and nonrestorative sleep with associated REM-related apneas/hypopneas, an elevated sleep EEG cyclical alternating pattern, and alpha EEG sleep anomaly. Post- SARS patients had symptoms of pre and post-sleep fatigue and post sleep sleepiness that were similar to the symptoms of patients with FMS, and similar to symptoms of patients with chronic fatigue syndrome. Both post-SARS and FMS groups had sleep instability as indicated by the high sleep EEG cyclical alternating pattern rate. The post-SARS group had a lower rating of the alpha EEG sleep anomaly as compared to the FMS patients. The post-SARS group also reported less pre-sleep and post-sleep musculoskeletal pain symptoms.</p> <p>Conclusions</p> <p>The clinical and sleep features of chronic post-SARS form a syndrome of chronic fatigue, pain, weakness, depression and sleep disturbance, which overlaps with the clinical and sleep features of FMS and chronic fatigue syndrome.</p
A multi-component flood risk assessment in the Maresme coast (NW Mediterranean)
Coastal regions are the areas most threatened by natural hazards, with floods being the most frequent and significant threat in terms of their induced impacts, and therefore, any management scheme requires their evaluation. In coastal areas, flooding is a hazard associated with various processes acting at different scales: coastal storms, flash floods, and sea level rise (SLR). In order to address the problem as a whole, this study presents a methodology to undertake a preliminary integrated risk assessment that determines the magnitude of the different flood processes (flash flood, marine storm, SLR) and their associated consequences, taking into account their temporal and spatial scales. The risk is quantified using specific indicators to assess the magnitude of the hazard (for each component) and the consequences in a common scale. This allows for a robust comparison of the spatial risk distribution along the coast in order to identify both the areas at greatest risk and the risk components that have the greatest impact. This methodology is applied on the Maresme coast (NW Mediterranean, Spain), which can be considered representative of developed areas of the Spanish Mediterranean coast. The results obtained characterise this coastline as an area of relatively low overall risk, although some hot spots have been identified with high-risk values, with flash flooding being the principal risk process
The Microcephalin Ancestral Allele in a Neanderthal Individual
Background: The high frequency (around 0.70 worlwide) and the relatively young age (between 14,000 and 62,000 years) of a derived group of haplotypes, haplogroup D, at the microcephalin (MCPH1) locus led to the proposal that haplogroup D originated in a human lineage that separated from modern humans.1 million years ago, evolved under strong positive selection, and passed into the human gene pool by an episode of admixture circa 37,000 years ago. The geographic distribution of haplogroup D, with marked differences between Africa and Eurasia, suggested that the archaic human form admixing with anatomically modern humans might have been Neanderthal. Methodology/Principal Findings: Here we report the first PCR amplification and high- throughput sequencing of nuclear DNA at the microcephalin (MCPH1) locus from Neanderthal individual from Mezzena Rockshelter (Monti Lessini, Italy). We show that a well-preserved Neanderthal fossil dated at approximately 50,000 years B.P., was homozygous for the ancestral, non-D, allele. The high yield of Neanderthal mtDNA sequences of the studied specimen, the pattern of nucleotide misincorporation among sequences consistent with post-mortem DNA damage and an accurate control of the MCPH
The expansion field: The value of H_0
Any calibration of the present value of the Hubble constant requires
recession velocities and distances of galaxies. While the conversion of
observed velocities into true recession velocities has only a small effect on
the result, the derivation of unbiased distances which rest on a solid zero
point and cover a useful range of about 4-30 Mpc is crucial. A list of 279 such
galaxy distances within v<2000 km/s is given which are derived from the tip of
the red-giant branch (TRGB), from Cepheids, and from supernovae of type Ia (SNe
Ia). Their random errors are not more than 0.15 mag as shown by
intercomparison. They trace a linear expansion field within narrow margins from
v=250 to at least 2000 km/s. Additional 62 distant SNe Ia confirm the linearity
to at least 20,000 km/s. The dispersion about the Hubble line is dominated by
random peculiar velocities, amounting locally to <100 km/s but increasing
outwards. Due to the linearity of the expansion field the Hubble constant H_0
can be found at any distance >4.5 Mpc. RR Lyr star-calibrated TRGB distances of
78 galaxies above this limit give H_0=63.0+/-1.6 at an effective distance of 6
Mpc. They compensate the effect of peculiar motions by their large number.
Support for this result comes from 28 independently calibrated Cepheids that
give H_0=63.4+/-1.7 at 15 Mpc. This agrees also with the large-scale value of
H_0=61.2+/-0.5 from the distant, Cepheid-calibrated SNe Ia. A mean value of
H_0=62.3+/-1.3 is adopted. Because the value depends on two independent zero
points of the distance scale its systematic error is estimated to be 6%.
Typical errors of H_0 come from the use of a universal, yet unjustified P-L
relation of Cepheids, the neglect of selection bias in magnitude-limited
samples, or they are inherent to the adopted models.Comment: 44 pages, 4 figures, 6 tables, accepted for publication in the
Astronony and Astrophysics Review 15
- …