Genetic Determinants of Time Perception Mediated by the Serotonergic System

Background: The present study investigates neurobiological underpinnings of individual differences in time perception. Methodology: Forty-four right-handed Russian Caucasian males (18–35 years old) participated in the experiment. The polymorphism of the genes related to the activity of serotonin (5-HT) and dopamine (DA)-systems (such as 5-HTT, 5HT2a, MAOA, DAT, DRD2, COMT) was determined upon the basis of DNA analysis according to a standard procedure. Time perception in the supra-second range (mean duration 4.8 s) was studied, using the duration discrimination task and parametric fitting of psychometric functions, resulting in individual determination of the point of subjective equality (PSE). Assuming the ‘dual klepsydra model ’ of internal duration representation, the PSE values were transformed into equivalent values of the parameter k (kappa), which is a measure of the ‘loss rate ’ of the duration representation. An association between time representation parameters (PSE and k, respectively) and 5-HT-related genes was found, but not with DArelated genes. Higher ‘loss rate ’ (k) of the cumulative duration representation were found for the carriers of genotypes characterized by higher 5-HT transmission, i.e., 1) lower 5-HT reuptake, known for the 5-HTTLPR SS polymorphism compared with LL, 2) lower 5-HT degradation, described for the ‘low expression ’ variant of MAOA VNTR gene compared with ‘high expression ’ variant, and 3) higher 5-HT2a receptor density, proposed for the TT polymorphism of 5-HT2a T102C gene compared with CC

Characterisation of the Nematode Community of a Low-Activity Cold Seep in the Recently Ice-Shelf Free Larsen B Area, Eastern Antarctic Peninsula

Background: Recent climate-induced ice-shelf disintegration in the Larsen A (1995) and B (2002) areas along the Eastern Antarctic Peninsula formed a unique opportunity to assess sub-ice-shelf benthic community structure and led to the discovery of unexplored habitats, including a low-activity methane seep beneath the former Larsen B ice shelf. Since both limited particle sedimentation under previously permanent ice coverage and reduced cold-seep activity are likely toinfluence benthic meiofauna communities, we characterised the nematode assemblage of this low-activity cold seep and compared it with other, now seasonally ice-free, Larsen A and B stations and other Antarctic shelf areas (Weddell Sea and Drake Passage), as well as cold-seep ecosystems world-wide.Principal Findings: The nematode community at the Larsen B seep site differed significantly from other Antarctic sites in terms of dominant genera, diversity and abundance. Densities in the seep samples were high (.2000 individuals per 10 cm2) and showed below-surface maxima at a sediment depth of 2–3 cm in three out of four replicates. All samples were dominated by one species of the family Monhysteridae, which was identified as a Halomonhystera species that comprised between 80 and 86% of the total community. The combination of high densities, deeper density maxima and dominance of one species is shared by many cold-seep ecosystems world-wide and suggested a possible dependence upon a chemosynthetic food source. Yet stable 13C isotopic signals (ranging between 221.9760.86% and 224.8561.89%) were indicative of a phytoplankton-derived food source.Conclusion: The recent ice-shelf collapse and enhanced food input from surface phytoplankton blooms were responsible for the shift from oligotrophic pre-collapse conditions to a phytodetritus-based community with high densities and low diversity. The parthenogenetic reproduction of the highly dominant Halomonhystera species is rather unusual for marine nematodes and may be responsible for the successful colonisation by this single species

Regional Arterial Stiffness in Patients with Inflammatory Bowel Disease

Aim.  To study muscular (brachial and radial arteries) and elastic (aorta) regional arterial stiffness in IBD patients in comparison with those without IBD, as well as to establish the relationship between arterial stiffness and the characteristics of the IBD course (the duration of illness, severity of attack, activity of systemic inflammation). Materials and methods. The study included 21 IBD patients and 30 patients in the comparison group. The values of regional aortic and muscular arterial stiffness were measured by applanation tonometry. The carotid–femoral pulse wave velocity (cfPWV) and the carotid-radial pulse wave velocity (crPWV) were determined. The laboratory research plan included the analysis of complete blood count, biochemical parameters, fibrinogen and a high sensitivity  C-reactive protein (hsCRP).Results. crPWV, similar to cfPWV, was not significantly different between the groups. At the same time, the proportion of individuals with an increase in the cfPWV of more than 10 m/s was higher in the group of IBD patients. However, these differences did not reach the level of statistical significance. According to the results of the correlation analysis, the increase in cfPWV was associated with an increase in patient age (r = 0.564; p = 0.01), the duration of IBD history (r = 0.628; p = 0.003), fasting plasma glucose (r = 0.367; p = 0.034) and GFR decrease (r = -0.482; p = 0.031). The crPWV also directly correlated with the IBD duration (r = 0.630; p = 0.003). According to the results of the regression analysis, an increase in the IBD duration by 1 year is associated with an increase in cfPWV by 0.205 m/s, i.e. the increase in the IBD duration by 5 years is associated with an increase in the cfPWV of approximately 1 m/s.Conclusion. In IBD patients, the duration of the disease directly correlated with an increase in cfPWV and crPWV. The increase in the IBD duration by 1 year was associated with an increase in cfPWV by 0.205 m/s. The muscular and elastic regional arterial stiffness was not statistically significantly different between IBD patients and the comparison group

Ultrasound examination of achilles tendons in patients with familial hypercholesterolemia

Aim. To assess the morphometric characteristics of Achilles tendons in patients with familial hypercholesterolemia (FH) and to identify factors associated with an increase in their size.Материал и  методы. Totally, 100 patients included, with severe primary hyperlipidemia, defined as an increase in total cholesterol ≥7,5 mM/L and/or lowdensity lipoprotein cholesterol ≥4,9 mM/L. All patients underwent duplex scanning of carotid arteries. Ultrasound examination of the Achilles tendons was carried out on an expert class ultrasound equipment Samsung Medison EKO 7 (Japan) with a linear sensor, frequency of 7-16 MHz. Thickness of the Achilles tendon (anteriorposterior dimension (APD)) was measured during scanning in the longitudinal section, width (transverse dimension (TD)) — scanning in the cross section. The measurements were made 2 cm proximal to the calcaneus.Results. Among the participants, 32 (32,0%) had definite/probable diagnosis of FH. In patients with definite/probable FH the mean values   of APD were significantly higher in comparison with patients scored 5 or less points (DLCN) — 5,50 (4,70-6,10) mm vs. 5,00 (4,50-5,40), respectively (p=0,04). TD of Achilles tendons among this category of patients was also statistically significantly higher in comparison with the rest of patients — 14,0 (12,9-15,4) mm and 13,2 (12,2-14,2) mm, respectively (p=0,04). In correlation analysis, the relationship between the growth of patients and the APD of the Achilles tendons (r=0,34, p=0,001), the TD of the Achilles tendon (r=0,28, p=0,009), CIMT and TD of the Achilles tendons (r=0,21, p=0,05), amount of carotid plaques and TD of the Achilles tendon (r=0,26, p=0,01), total percentage of stenosis of the carotid arteries and the TD of the Achilles tendons (r=0,27, p=0,01), maximum percentage of stenosis of the carotid arteries and the TD of the Achilles tendons (r=0,28, p=0,007). According to regression analysis, factors associated with an increase in thickness of the Achilles tendons for more than 75 percentiles were male sex, diabetes mellitus, height, myocardial infarction in relatives, total percentage of stenosis of the carotid arteries and high-density lipoproteide cholesterol.Conclusion. In patients with definite/probable FH, mean values of width and thickness of the Achilles tendons were significantly higher in comparison with the rest of the patients. According to regression analysis, the factors associated with the increase in thickness of the Achilles tendons fro more than 75 percentiles were male sex, diabetes mellitus, height, myocardial infarction in relatives, total percentage of stenosis of the carotid arteries and HDL high-density lipoproteide cholesterol

Community dynamics of nematodes after Larsen ice-shelf collapse in the eastern Antarctic Peninsula

Free-living marine nematode communities of the Larsen B embayment at the eastern Antarctic Peninsula were investigated to provide insights on their response and colonization rate after large-scale ice-shelf collapse. This study compares published data on the post-collapse situation from 2007 with new material from 2011, focusing on two locations in the embayment that showed highly divergent communities in 2007 and that are characterized by a difference in timing of ice-shelf breakup. Data from 2007 exposed a more diverse community at outer station B.South, dominated by the genus Microlaimus. On the contrary, station B.West in the inner part of Larsen B was poor in both numbers of individuals and genera, with dominance of a single Halomonhystera species. Re-assessment of the situation in 2011 showed that communities at both stations diverged even more, due to a drastic increase in Halomonhystera at B.West compared to relatively little change at B.South. On a broader geographical scale, it seems that B.South gradually starts resembling other Antarctic shelf communities, although the absence of the genus Sabatieria and the high abundance of Microlaimus still set it apart nine years after the main Larsen B collapse. In contrast, thriving of Halomonhystera at B.West further separates its community from other Antarctic shelf areas