Increased p wave dispersion in elite athletes

Background

Few studies have been performed on P wave indices in athletes. The aim of this study was to determine the behaviour of maximum P wave duration (Pmax), minimum P wave duration (Pmin) and P wave dispersion (PWD) in young high performance athletes, as well as the relationship of PWD with training history, heart rate (HR) and echocardiographic parameters.

Methods

We performed a cross-sectional observational study in 38 athletes of high performance in sports: water polo, distance running and weight lifting compared with 34 sedentary controls.

Results

The average age in both groups was 20.6 years. Note that PWD was increased in athletes (57 ± 14 ms vs. 40 ± 12 ms, p <0.001) while Pmin was significantly lower (57 ± 13 ms vs. 72 ± 13 ms, p <0.001), and there was no difference when comparing Pmax (114 ± 9 ms vs. 117 ± 14 ms, p> 0.05). The correlation between the duration of training (r = 0.511) and resting HR (r = 0.461) with PWD was significant (p <0.01).

Conclusions

PWD is increased in young athletes of high performance and was positively correlated with duration of training and baseline HR. The increase in PWD was secondary to a significant decrease in Pmin.     

Extraction of the climatic signal for moisture from tree-ring chronologies of Altai-Sayan mountain forest-steppes

Studies in Central Asia (Altai-Sayan region, northwest and central Mongolia) have shown that trees growing in arid conditions of mountain forest-steppes have a mixed and unstable climatic response. It is obvious that this nature of the climatic response of trees prevents the use of tree-ring chronologies for climate reconstruction. In this connection, it is necessary to separate the climatic signal of tree-ring chronologies, i.e., extract the signal for moisture. This paper proposes a method for separating the climatic signal of tree-ring chronologies of mountain forest-steppes, and reports estimates of its reliability by two independent methods. Analysis of the chronologies obtained after separation of the signal, based on meteorological and hydrological data, has shown that these chronologies can be used for climate reconstructions.     

Plasma biomarkers of brain atrophy in Alzheimer's disease

Peripheral biomarkers of Alzheimer''s disease (AD) reflecting early neuropathological change are critical to the development of treatments for this condition. The most widely used indicator of AD pathology in life at present is neuroimaging evidence of brain atrophy. We therefore performed a proteomic analysis of plasma to derive biomarkers associated with brain atrophy in AD. Using gel based proteomics we previously identified seven plasma proteins that were significantly associated with hippocampal volume in a combined cohort of subjects with AD (N = 27) and MCI (N = 17). In the current report, we validated this finding in a large independent cohort of AD (N = 79), MCI (N = 88) and control (N = 95) subjects using alternative complementary methods—quantitative immunoassays for protein concentrations and estimation of pathology by whole brain volume. We confirmed that plasma concentrations of five proteins, together with age and sex, explained more than 35% of variance in whole brain volume in AD patients. These proteins are complement components C3 and C3a, complement factor-I, γ-fibrinogen and alpha-1-microglobulin. Our findings suggest that these plasma proteins are strong predictors of in vivo AD pathology. Moreover, these proteins are involved in complement activation and coagulation, providing further evidence for an intrinsic role of these pathways in AD pathogenesis.     

Proton-linked subunit heterogeneity in ferrous nitrosylated human adult hemoglobin: an EPR study

The effect of pH on the X-band electron paramagnetic resonance (EPR) spectrum of ferrous nitrosylated human adult tetrameric hemoglobin (HbNO) as well as of ferrous nitrosylated monomeric alpha- and beta-chains has been investigated, at -163 degrees C. At pH 7.3, the X-band EPR spectrum of tetrameric HbNO and ferrous nitrosylated monomeric alpha- and beta-chains displays a rhombic shape. Lowering the pH from 7.3 to 3.0, tetrameric HbNO and ferrous nitrosylated monomeric alpha- and beta-chains undergo a transition towards a species characterized by a X-band EPR spectrum with a three-line splitting centered at 334mT. These pH-dependent spectroscopic changes may be taken as indicative of the cleavage, or the severe weakening, of the proximal HisF8-Fe bond. In tetrameric HbNO, the pH-dependent spectroscopic changes depend on the acid-base equilibrium of two apparent ionizing groups with pK(a) values of 5.8 and 3.8. By contrast, the pH-dependent spectroscopic changes occurring in ferrous nitrosylated monomeric alpha- and beta-chains depend on the acid-base equilibrium of one apparent ionizing group with pK(a) values of 4.8 and 4.7, respectively. The different pK(a) values for the proton-linked spectroscopic transition(s) of tetrameric HbNO and ferrous nitrosylated monomeric alpha- and beta-chains suggest that the quaternary assembly drastically affects the strength of the proximal HisF8-Fe bond in both subunits. This probably reflects a 'quaternary effect', i.e., structural changes in both subunits upon tetrameric assembly, which is associated to a relevant variation of functional properties (i.e., proton affinity).     

Pharmacological analysis of CCK2 receptors up-regulated using engineered transcription factors

Designed zinc finger proteins (ZFPs) regulate expression of target genes when coupled to activator or repressor domains. Transfection of ZFPs into cell lines can create expression systems where the targeted endogenous gene is transcribed and the protein of interest can be investigated in its own cellular context. Here we describe the pharmacological investigation of an expression system generated using CCK2 receptor-selective ZFPs transfected into human embryonic kidney cells (HEKZFP system). The receptors expressed in this system, in response to ZFP expression, were functional in calcium mobilization studies and the potency of the agonists investigated was consistent with their action at CCK2 receptors (CCK-8S pA50 = 9.05+/-0.11, pentagastrin pA50 = 9.11+/-0.13). In addition, binding studies were conducted using [125I]-BH-CCK-8S as radioligand. The saturation binding analysis of this radioligand was consistent with a single population of high affinity CCK receptors (pK(D) = 10.24). Competition studies were also conducted using a number of previously well-characterized CCK-receptor selective ligands; JB93182, YF476, PD-134,308, SR27897, dexloxiglumide, L-365,260 and L-364,718. Overall, the estimated affinity values for these ligands were consistent with their interaction at CCK2 receptors. Therefore, CCK2 receptors up-regulated using zinc finger protein technology can provide an alternative to standard transfection techniques for the pharmacological analysis of compounds.     

Ochratoxin A-induced renal cortex fibrosis and epithelial-to-mesenchymal transition: molecular mechanisms of ochratoxin A-injury and potential effects of red wine

We characterized the effect of chronic ochratoxin A (OTA) on rat kidney cortex, analyzing collagen content and collagen turnover and the major markers of epithelial-to-mesenchymal transition (EMT), such as alpha-smooth muscle actin (alphaSMA), cadherins, and MMP-9. Because OTA nephrotoxicity is mediated by free radicals, we also investigated whether antioxidants in red wine provided protection for the kidney and attenuated OTA-induced EMT. Collagen content, determined by computerized analysis of Sirius red-stained kidney sections, increased in OTA, OTA-wine, and OTA-EtOH treated rats. In kidney cortex homogenates, COL-I and COL-III mRNA levels tended to rise in OTA treated rats, but were similar to CT after OTA-wine and OTA-EtOH administration. TIMP-1 gene expression was up-regulated in OTA, OTA-wine, and OTA-EtOH treated rats. LH2b mRNA/COL-I mRNA was significantly up-regulated in OTA-wine and OTA-EtOH treated rats, compared with CT and OTA alone. TGF-beta1 signaling tended to dominate after OTA, OTA-wine, and OTA-EtOH. MMP-1 protein levels were not affected. OTA induced proMMP-9 and alphaSMA overexpression, decreases of E-cadherin and N-cadherin, and DSC-2 up-regulation. OTA-wine caused a further, unexpected decrease of E- and N-cadherins and further up-regulation of OTA-induced DSC-2, while strongly reducing the OTA-induced increases of alphaSMA and proMMP-9. Posttranslational collagen modifications, such as decreased collagen degradation through MMP inhibition and increased collagen cross-links, seem to be key mechanisms leading to OTA-induced kidney cortex fibrosis. This mechanism was not affected by red wine in these conditions. Red wine seems to have some protective role against OTA-induced EMT, although without completely blocking the process and determining a condition in which abundant cells display an intermediate translational phenotype, but there are no alphaSMA or epithelial markers.     

The HIF prolyl hydroxylase PHD3 is a potential substrate of the TRiC chaperonin

Hypoxia-inducible factor-1 (HIF) is regulated by oxygen-dependent prolyl hydroxylation. Of the three HIF prolyl hydroxylases (PHD1, 2 and 3) identified, PHD3 exhibits restricted substrate specificity in vitro and is induced in different cell types by diverse stimuli. PHD3 may therefore provide an interface between oxygen sensing and other signalling pathways. We have used co-purification and mass spectrometry to identify proteins that interact with PHD3. The cytosolic chaperonin TRiC was found to copurify with PHD3 in extracts from several cell types. Our results indicate that PHD3 is a TRiC substrate, providing another step at which PHD3 activity may be regulated.     

Feeding by numbers: an ethnographic study of how breastfeeding women understand their babies' weight charts

Background

Assisting mothers to breastfeed is not easy when babies experience difficulties. In a neonatal intensive care unit (NICU), nurses often help mothers by using hands-on-breast without their permission. Little is known about how mothers feel about this unusual body touching. To gain more knowledge from mothers who lived through this experience, this hands-on practice was studied in a NICU in Sweden.

Methods

Between January and June 2001, in-depth interviews were conducted with ten mothers of preterm or sick term infants and all of them experienced the hands-on approach. In this research, Radnitzky's seven principles of hermeneutic interpretation were applied in order to interpret the meaning of mothers' responses. This article presents results related to the period of initiation of breastfeeding. This qualitative study was based on a combination of the models of Gustafsson, Orem, and Aarts' Marte Meo.

Results

Five main themes were identified: Insult to integrity, Manipulating the baby, Understanding and adjustment, Breasts as objects, Alternatives to this practice. Hands-on help in the breastfeeding situation was experienced as unpleasant and the women experienced their breasts as objectified. The mothers accepted the hands-on help given by nursing staff, even though they considered it unpleasant. Most mothers expressed a need for assistance when starting breastfeeding, but could not suggest any alternative to hands-on help such as demonstrating with an artificial breast and a doll.

Conclusion

The study provides information about how mothers experience unexpected hands-on help with breastfeeding in a NICU, which has not been described previously. Since most mothers in this study regarded this behavior as unpleasant and not helpful mostly because it was unexpected and unexplained, it would be important to either explain beforehand to mothers what type of physical approach could be attempted on their body or better, to avoid this type of approach completely.     

Synthesis and antimicrobial activity of some new N-glycosides of 2-thioxo-4-thiazolidinone derivatives

5-Arylidene-2-thioxo-4-thiazolidinones 3a-f react with each of 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl and α-d-galactopyranosyl bromides 4a,b in acetone in the presence of aqueous potassium hydroxide at room temperature to afford N-(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl) or N-(2,3,4,6-tetra-O-acetyl-β-d-galactopyranosyl) 2-thioxo-4-thiazolidinone derivatives 5a-f. Similarly, the reaction of 5-cycloalkylidene-2-thioxo-4-thiazolidinones 7a,b with 4a gave the corresponding N-glucosides 8a,b. Also, 5-pyrazolidene rhodanines 10a-e react with 4a to afford the new N-glucosides 11a-e. Treatment of compounds 15 and 16 with 4a in the presence of few drops of triethylamine or in KOH solution accomplished the mono- and bis-nucleosides 17 and 18, respectively. Some selected products were tested for their antimicrobial activities.