Spatio-temporal population structuring and genetic diversity retention in depleted Atlantic Bluefin tuna of the Mediterranean Sea

Fishery genetics have greatly changed our understanding of population dynamics and structuring in marine fish. In this study, we show that the Atlantic Bluefin tuna (ABFT, Thunnus thynnus), an oceanic predatory species exhibiting highly migratory behavior, large population size, and high potential for dispersal during early life stages, displays significant genetic differences over space and time, both at the fine and large scales of variation. We compared microsatellite variation of contemporary (n = 256) and historical (n = 99) biological samples of ABFTs of the central-western Mediterranean Sea, the latter dating back to the early 20th century. Measures of genetic differentiation and a general heterozygote deficit suggest that differences exist among population samples, both now and 96–80 years ago. Thus, ABFTs do not represent a single panmictic population in the Mediterranean Sea. Statistics designed to infer changes in population size, both from current and past genetic variation, suggest that some Mediterranean ABFT populations, although still not severely reduced in their genetic potential, might have suffered from demographic declines. The short-term estimates of effective population size are straddled on the minimum threshold (effective population size = 500) indicated to maintain genetic diversity and evolutionary potential across several generations in natural populations.     

Analbuminemia in a Swedish male is caused by the Kayseri mutation (c228_229delAT)

BACKGROUND: Analbuminemia is a rare autosomal recessive disorder manifested by the absence, or severe reduction, of circulating serum albumin. Here we report the first case of hereditary analbuminemia in the ethnic Swedish population, and we define the molecular defect that causes the analbuminemic trait. METHODS: Total DNA, extracted from peripheral blood samples from the analbuminemic proband and his parents, was PCR-amplified using oligonucleotide primers designed to amplify the 14 exons, the exon-intron splice junctions, and the 5' and 3' untranslated regions of the albumin gene. The products were screened for mutations by single-strand conformation polymorphism and heteroduplex analyses. The latter allowed the identification of the abnormal fragment, which was then sequenced. RESULTS: The analbuminemic trait of the proband was caused by a homozygous AT deletion at nucleotides c. 228-229, the 91st and 92nd bases of exon 3. This defect, previously identified as Kayseri mutation [M. Galliano, M. Campagnoli, A. Rossi, et al. Molecular diagnosis of analbuminemia: a novel mutation identified in two Amerindian and two Turkish families. Clin Chem 2002;48: 844-849.], produces a frameshift leading to a premature stop, two codons downstream. CONCLUSIONS: The Kayseri mutation appears to be the most common cause of analbuminemia in humans, and is found in individuals belonging to geographically distant, and apparently unrelated ethnic groups.     

Human interleukin 17-producing cells originate from a CD161+CD4+ T cell precursor

We demonstrate that CD161 is a highly up-regulated gene in human interleukin (IL) 17 T helper cell (Th17) clones and that all IL-17–producing cells are contained in the CD161⁺ fraction of CD4⁺ T cells present in the circulation or in inflamed tissues, although they are not CD1-restricted natural killer T cells. More importantly, we show that all IL-17–producing cells originate from CD161⁺ naive CD4⁺ T cells of umbilical cord blood, as well as of the postnatal thymus, in response to the combined activity of IL-1β and IL-23. These findings implicate CD161 as a novel surface marker for human Th17 cells and demonstrate the exclusive origin of these cells from a CD161⁺CD4⁺ T cell progenitor.     

Effects of Parkinson's disease and levodopa on functional limits of stability

BACKGROUND: The voluntary, maximum inclined posture reflects the self-perceived limits of stability. Parkinson's disease is associated with small, bradykinetic postural weight shifts while standing but it is unclear whether this is due to reduced limits of stability and/or to the selection of abnormal strategies for leaning. The aim of this study was to investigate the effects of Parkinson's disease and levodopa medication on voluntary limits of stability and strategies used to reach these limits. METHODS: Fourteen subjects with Parkinson's disease (OFF and ON levodopa) and 10 age-matched controls participated in the study. Functional limits of stability were quantified as the maximum center of pressure excursion during voluntary forward and backward leaning. Postural strategies to achieve functional limits of stability were assessed by (i) body segments alignment, (ii) the difference between center of pressure and center of mass in preparation for a lean, (iii) the timing and the velocity of the preparation phase. FINDINGS: Functional limits of stability were significantly smaller in subjects with Parkinson's disease compared to control subjects. Subjects with Parkinson's disease maintained their stooped posture while leaning, initiated leaning with a smaller difference between center of pressure and center of mass and had a slower leaning velocity compared to control subjects. Levodopa enlarged the limits of stability in subjects with Parkinson's disease because of an increase in maximum forward, but not backward leans, but did not significantly improve postural alignment, preparation for a leaning movement, or velocity of leaning. INTERPRETATION: Parkinson's disease reduces functional limits of stability as well as the magnitude and velocity of postural preparation during voluntary, forward and backward leaning while standing. Levodopa improves the limits of stability but not the postural strategies used to achieve the leaning.     

Modular structure of awareness for sensorimotor disorders: evidence from anosognosia for hemiplegia and anosognosia for hemianaesthesia

In the present paper, we shall review clinical evidence and theoretical models related to anosognosia for sensorimotor impairments that may help in understanding the normal processing underlying conscious self-awareness. The dissociations between anosognosia for hemiplegia and anosognosia for hemianaesthesia are considered to give important clinical evidence supporting the hypothesis that awareness of sensory and motor deficits depends on the functioning of discrete self-monitoring processes. We shall also present clinical and anatomical data on four single case reports of patients selectively affected by anosognosia for hemianaesthesia. The differences in the anatomical localization of lesions causing anosognosia for hemiplegia and anosognosia for hemianaesthesia are taken as evidence that cerebral circuits subserving these monitoring processes are located in separate brain areas, which may be involved both in the execution of primary functions and the emergence of awareness related to the monitoring of the same functions. The implications of these findings for the structure of conscious processes shall be also discussed.     

Lack of biological relevance of platelet cyclooxygenase-2 dependent thromboxane A2 production

INTRODUCTION: There is emerging evidence of a considerable variability of the impact of aspirin on clinical outcome and laboratory findings. Persistent TxA2 production seems to be the most likely reason. Aim of this study was to determine whether the mechanism responsible for TxA2 persistent production is, at least partially, dependent upon aspirin-insensitive platelet COX-2 enzymatic pathway. METHODS AND RESULTS: In 100 consecutive patients, under chronic aspirin anti-platelet treatment (100-160 mg/day) selected on the basis of detectable plasma salicylate levels, serum and Arachidonic Acid (AA)-induced platelet TxA2 production, immunoblot analysis of platelet COX-1/COX-2 expression and COX-2 activity were studied. Immunoblot revealed COX-2 expression in 46% patients, in an amount that was markedly lower than COX-1. In 10 COX-2 positive patients with TxA2 levels over the median, AA-induced TxA2 production performed in vitro in the presence of the COX-2 inhibitor CAY10404 and aspirin demonstrated that COX-2 dependent TxA2 production is less than 2%. CONCLUSION: Our data demonstrate that the inter-individual variability of platelet sensitivity to aspirin is due to a reduced efficacy of aspirin on platelet COX-1 despite ascertained patient compliance. We suggest that serum TxA2 assay might be performed in future clinical studies to improve our knowledge on the residual TxA2 production in aspirin-treated patients.     

Alexithymia in multiple sclerosis: relationship with fatigue and depression

Objective –  The aim of this study was to investigate the prevalence of alexithymia in a sample of patients with multiple sclerosis (MS) and to further evaluate the association between alexithymia and the occurrence of common disabling MS-related symptoms such as fatigue and depression.
Methods –  Fifty-eight relapsing–remitting MS patients treated with interferon (IFN)-beta-1a underwent a complete neurological evaluation, including Expanded Disability Status Scale score assessment. Alexithymia, depressive symptoms and fatigue were assessed using the 20-item Toronto Alexithymia Scale, Beck Depression Inventory and Fatigue Severity Scale.
Results –  Prevalence of alexithymia was 13.8%, with 27.6% of patients presenting borderline alexithymia. Sixty-seven per cent of the patients complained of fatigue while 29.3% of them were depressed. Higher levels of fatigue and depression were found in alexithymic patients when compared with non-alexithymic patients. Results from logistic regressions showed that alexithymia significantly contributes to the severity of fatigue and depression.
Conclusions –  Alexithymia was associated with increased severity of fatigue and depression.