Interatrial blocks. A separate entity from left atrial enlargement: a consensus report

Impaired interatrial conduction or interatrial block is well documented but is not described as an individual electrocardiographic (ECG) pattern in most of ECG books, although the term atrial abnormalities to encompass both concepts, left atrial enlargement (LAE) and interatrial block, has been coined. In fact, LAE and interatrial block are often associated, similarly to what happens with ventricular enlargement and ventricular block. The interatrial blocks, that is, the presence of delay of conduction between the right and left atria, are the most frequent atrial blocks. These may be of first degree (P-wave duration >120 milliseconds), third degree (longer P wave with biphasic [±] morphology in inferior leads), and second degree when these patterns appear transiently in the same ECG recording (atrial aberrancy). There are evidences that these electrocardiographic P-wave patterns are due to a block because they may (a) appear transiently, (b) be without associated atrial enlargement, and (c) may be reproduced experimentally. The presence of interatrial blocks may be seen in the absence of atrial enlargement but often are present in case of LAE. The most important clinical implications of interatrial block are the following: (a) the first degree interatrial blocks are very common, and their relation with atrial fibrillation and an increased risk for global and cardiovascular mortality has been demonstrated; (b) the third degree interatrial blocks are less frequent but are strong markers of LAE and paroxysmal supraventricular tachyarrhythmias. Their presence has been considered a true arrhythmological syndrome.     

Dietary Natural Compounds and Vitamins as Potential Cofactors in Uterine Fibroids Growth and Development

An analysis of the literature generated within the past 20 year-span concerning risks of uterine fibroids (UFs) occurrence and dietary factors was carried out. A link between Vitamin D deficiency and UFs formation is strongly indicated, making it a potent compound in leiomyoma therapy. Analogs of the 25-hydroxyvitamin D3, not susceptible to degradation by tissue 24-hydroxylase, appear to be especially promising and tend to show better therapeutic results. Although research on the role of Vitamin A in the formation of fibroids is contradictory, Vitamin A-enriched diet, as well as synthetic retinoid analogues, may be preventative or limit the growth of fibroids. Unambiguous conclusions cannot be drawn regarding Vitamin E and C supplementation, except for alpha-tocopherol. Alpha-tocopherol as a phytoestrogen taking part in the modulation of estrogen receptors (ERs) involved in UF etiology, should be particularly avoided in therapy. A diet enriched in fruits and vegetables, as sources of carotenoids, polyphenols, quercetin, and indole-3-carbinol, constitutes an easily modifiable lifestyle element with beneficial results in patients with UFs. Other natural substances, such as curcumin, can reduce the oxidative stress and protect against inflammation in leiomyoma. Although the exact effect of probiotics on uterine fibroids has not yet been thoroughly evaluated at this point, the protective role of dairy products, i.e., yogurt consumption, has been indicated. Trace elements such as selenium can also contribute to antioxidative and anti-inflammatory properties of a recommended diet. In contrast, heavy metals, endocrine disrupting chemicals, cigarette smoking, and a diet low in antioxidants and fiber were, alongside genetic predispositions, associated with UFs formation.     

Hydration Processes of Four-Component Binders Containing a Low Amount of Cement

Results of research on hydration of four-component binders containing very high amounts of supplementary cementitious materials were presented. The samples were composed of blended pozzolana (a mix of conventional fly ash and spent aluminosilicate catalyst), cement (about 20 wt.% in the binder) and Ca(OH)₂. Spent aluminosilicate catalyst was proposed as activating component which can improve properties of low-cement blends, while the role of Ca(OH)₂ was to enhance pozzolanic reaction. Early and later hydration periods of such blends were investigated by calorimetry, TG/DTG, FTIR and X-ray diffraction. Initial setting time as well as compressive strength were also determined. It was concluded that enhancement of reactivity and improvement of properties of fly ash–cement binders are possible by replacing a part of fly ash with more active fine-grained pozzolana and introducing additional amounts of Ca(OH)₂. The spent catalyst is mainly responsible for accelerating action during the first hours of hydration and for progress of early pozzolanic reaction. Fly ash develops its activity over time, thus synergic effect influences the later properties of composites. Samples containing blended pozzolana exhibit shorter initial setting times and higher compressive strength, as well as faster consumption of Ca(OH)₂ compared to the reference. Investigated mixtures seem to be promising as “green” binders, alternatives to cement, after optimizing their compositions or additional activating procedure.     

Study of Nano h-BN Impact on Lubricating Properties of Selected Oil Mixtures

Our experiments aimed to study the influence of layered materials with nanometric-scale particles, which are part of lubricant oils, on their tribological properties. The object of this study was a lubricant oil made using base oil PAO4, which contained nanoparticle hexagonal boron nitride (nano h-BN) and a dispersant based on succinic acid imide. Comparative tests for engine oil (CB30) were also performed. The paper presents the method of preparing the test material and the tribological test results, including wear spot diameter (wear mark), limit wear load, and seizure load. The test results obtained demonstrate that nano-hexagonal boron nitride improves the tribological properties of lubricant oils. However, oil preparation and the quantitative selection of components markedly influence the results.     

Can increased spatial resolution solve the crossing fiber problem for diffusion MRI?

It is now widely recognized that voxels with crossing fibers or complex geometrical configurations present a challenge for diffusion MRI (dMRI) reconstruction and fiber tracking, as well as microstructural modeling of brain tissues. This “crossing fiber” problem has been estimated to affect anywhere from 30% to as many as 90% of white matter voxels, and it is often assumed that increasing spatial resolution will decrease the prevalence of voxels containing multiple fiber populations. The aim of this study is to estimate the extent of the crossing fiber problem as we progressively increase the spatial resolution, with the goal of determining whether it is possible to mitigate this problem with higher resolution spatial sampling. This is accomplished using ex vivo MRI data of the macaque brain, followed by histological analysis of the same specimen to validate these measurements, as well as to extend this analysis to resolutions not yet achievable in practice with MRI. In both dMRI and histology, we find unexpected results: the prevalence of crossing fibers increases as we increase spatial resolution. The problem of crossing fibers appears to be a fundamental limitation of dMRI associated with the complexity of brain tissue, rather than a technical problem that can be overcome with advances such as higher fields and stronger gradients.     

The Influence of Age at Menarche on the Menstrual Pattern of Polish University Students

PurposeThe aim of the study was to examine the relationships between age at menarche and menstrual cycle characteristics in young female subjects.MethodsAnthropometric measurements were performed, and questionnaire data were collected from 1,323 women, aged 19–25 years.ResultsNo differences were found in terms of cycle duration or the number of days of bleeding between women with early, average, or late menarche. Each of those groups had a similar percentage of women who declared that their cycles last longer than 35 days, those who declared that their cycles are shorter than 21 days, and those who reported prolonged bleeding. Irregular cycles were associated with late age at menarche. Women with early age at menarche complained about menstrual cramps more frequently. The existence of a relationship between age at menarche and menstrual cycle disorders was confirmed by the results of logistic regression.ConclusionsBoth early and late age at menarche are associated with increased risk of menstrual cycle disorders.     

Differences between the early and advanced stages of rheumatoid arthritis in the expression of EDA-containing fibronectin

In the present study the expression of alternatively spliced synovial EDA-containing FN (EDA-FN) was analyzed in plasma and synovial fluid samples of rheumatoid arthritis (RA) patients with from 2 months to 20 years disease duration. The patient samples were divided into groups: those with early, established, and late progressive radiographic changes as well as those with different disease activity established by a CRP concentration. The expression of EDA-FN was determined by sandwich-type ELISA using a specific anti-EDA monoclonal antibody. The relative amount of EDA-FN in synovial fluid, but not in plasma samples, was significantly lower in the early RA group than in established and late RA. In contrast, its level did not correlate with the CRP concentration. Synovial EDA-FN might be used as a supplemented marker of early RA.     

Durian (Durio zibethinus Murr.) cultivars as nutritional supplementation to rat's diets.

The properties of Mon Thong, Chani and Kan Yao durian (Durio zibethinus Murr.) cultivars were compared in vitro and in vivo studies in order to find the best one as a supplement to antiatherosclerotic diet. Total polyphenols (361.4+/-35.3 mgGAE/100g FW), flavonoids (93.9+/-8.9 mgCE/100g FW) and total antioxidant capacity determined by DPPH and beta-carotene-linoleic acid assays (261.3+/-25.3 microMTE/100g FW and 77.8+/-7.8% of inhibition) were maximal in Mon Thong in comparison with Chani and Kan Yao and showed a good correlation between these three variables (R(2)=0.9859). Five groups of rats were fed diets supplemented with cholesterol and different durian cultivars. Diets supplemented with Mon Thong and to a lesser degree with Chani and Kan Yao significantly hindered the rise in the plasma lipids (TC - 8.7%, 16.1% and 10.3% and (b) LDL-C - 20.1%, 31.3% and 23.5% for the Chol/Kan Yao, Chol/Mon Thong and Chol/Chani, respectively) and the decrease in plasma antioxidant activity (P<0.05). Nitrogen retention remained significantly higher in Chol/Mon Thong than in other diet groups. Diet supplemented with Mon Thong affected the composition of plasma fibrinogen in rats and showed more intensity in protein bands around 47 kDa. No lesions were found in the examined tissue of heart and brains. Mon Thong cultivar is preferable for the supplementation of the diet as positively influenced the lipid, antioxidant, protein and metabolic status. The durian fruit till now was not investigated extensively, therefore based on the results of this study durian cultivars can be used as a relatively new source of antioxidants.     

Trimetazidine limits the effects of myocardial ischaemia during percutaneous coronary angioplasty

This open-label, randomised, controlled study is aimed at assessing the effect of pre-treatment with the metabolic agent trimetazidine on the degree of ischaemia during percutaneous transluminal coronary angioplasty (PTCA). Overall 44 patients with one-vessel coronary artery stenosis (> 70%) in the medial part of the left anterior descending artery were included. One group (n = 22) was pre-treated with oral trimetazidine. The other group (n = 22) was the control. All patients (n = 44) were administered aspirin and conventional treatment. All patients underwent PTCA; stents were implanted in 11 trimetazidine patients and in seven control patients. The mean ST-segment elevation during all balloon inflations was significantly lower in the trimetazidine group than in the control group (-1.66 +/- 1.50 mm vs. 3.29 +/- 1.59 mm, p = 0.001). Maximal ST-segment elevations and mean ST elevation values during sequential balloon inflations were also significantly lower with trimetazidine (p = 0.018). The mean amplitude of the T-wave alterations during all balloon inflations was significantly lower with trimetazidine (3.09 +/- 2.39 mm vs. 6.83 +/- 4.31 mm; p = 0.001). Similarly, the maximal amplitude of the T-wave alterations was 4.50 +/- 2.90 mm with trimetazidine vs. 9.25 +/- 4.97 mm in control patients (p = 0.0005). Angina and rhythm disturbances were more frequent in the control group. Time from balloon inflation to onset of angina was 50 +/- 26.2 s with trimetazidine vs. 32 +/- 15.0 s, for control group (p = 0.03). The time to pain relief after deflation was 19.3 +/- 11.4 s with trimetazidine vs. 28.2 +/- 16.8 s (p = 0.001). Trimetazidine administered a few days before PTCA appears to be a cardioprotective agent for the prevention of myocardial ischaemia.