Permanent cardiac pacing and its influence on tricuspid valve function

Implantation of transvenous devices is a widespread procedure in clinical cardiology. It is well known that the presence of the electrodes in the cardiovascular system can induce fibrosis or fibrous adhesions between them and cause tricuspid regurgitation. Moreover there are suggestions that the placement of the electrode in the tricuspid orifice may also play a role in the development of tricuspid insufficiency because of the thickening of reactive leaflets and the impairment of their mobility in morphological studies. There are no papers regarding the topography of the electrode in the right ventricle judged by means of transthoracic echocardiography. Moreover in literature we did not meet reports comparing the localisation of the lead on the tricuspid valve function. Therefore we decided to describe the detailed topographic relations between the lead and the structures of the right ventricle in a larger population and we compared the influence of the lead location for tricuspid valve function. Research was carried out on a group of 86 patients (52 M, 34 F), with a mean age of 64.7 ± 14.9 years with permanent cardiac pacemaker or implantable cardioverter-defibrillator (ICD). On the basis of echocardiograms performed we assessed the position of the lead regarding the tricuspid valve leaflets or commissure, and judged the course of the lead beneath the tricuspid valve level. Moreover special attention was focused on the placement of the tip of the electrode. We qualified its position into three categories: apex of the right ventricle, right ventricle outflow tract, and “para-apex” position. The degree of the tricuspid valve insufficiency was assessed by means of semiquantitative method based on the Color-flow Doppler echocardiography. We measured the extension and the area of the tricuspid regurgitant jet using four-gradual scale. We compared the topography of the lead at the level of the valve with its function by means of the presence and degree of its regurgitation. We stated that in 35% of cases the pacing lead was located at the level of the anterior leaflet of the tricuspid valve, in 23% at the level of the septal leaflet and in 12% at the posterior one. Besides in 10% the electrode was placed between the leaflets just over the commissures. On the other hand in the remaining 20% the lead was positioned centrally in the right atrioventricular orifice without adherence to any leaflet. Next we assessed the course of the lead beneath the tricuspid valve level and stated that most frequently (45%) it run just across the centre of the right ventricle, and in other cases was lying along the interventricular septum (in 39% of cases) or along the anterior wall of the right ventricle(in 16%). The tip of the lead was positioned exactly in the apex of the right ventricle in 74%, in the right ventricular outflow tract in 9% and in 17% its position was “para-apical”. We did not see any statistically significant differences between the presence and intensification of valve regurgitation and topography of the lead. We concluded that at the level of the tricuspid valve the lead was positioned in the anteroseptal part of tricuspid annulus and the proper apical position of the electrode’s tip occurred in approximately 75% of cases. Localisation of the electrode at the level of the tricuspid orifice does not influence its insufficiency as detected by Doppler echocardiography

USE OF MODERN INFORMATION TECHNOLOGY IN MICROBIOLOGICAL LABORATORY

In today’s world, the utilisation of modern information technology is becoming increasingly common in educational process – not only at primary and secondary school level, but most of all, at university level. The present article is a proposition of the implementation of information technology as a complement of microbiological laboratories. These classes are, most of all, practical, so a tweak of programs and simulations forms a prominent challenge for an academic. A student, who participates in laboratories, achieves specified abilities, however, he or she does not always have an opportunity to preserve them. In the thesis, there is presented a proposition of innovations, implemented into the educational process, which are a result of a long-time educational practice in terms of educating on the university level. Inasmuch as a complex process of teaching and learning (complete with concurrent components, which qualify its didactic effectiveness) is a subject matter of general didactics, the utilisation of information technology may form an excellent complement of laboratories. The utilisation of such solutions helps students to preserve the practical skills, which they acquire in laboratories. The emphasis is on simulation programs, and the open-source learning management system Moodle, which are considered as educational tools which have a relevant impact on the tenor of learner’s cognitive processing. Taking into consideration the advantages of these tools, and the commonness of modern information technology, the authors indicated a large universality of this medium, and its usefulness in the problem and empirical teaching. The presented group of software may bring a significant contribution to the development, the desirability, and the increase of absorption in vocational training. The ponderations are based on the basis of the cognitive theory and the idea of constructive education

Left ventricle systolic volume in vasovagal syncope patients

One of the hypotheses put forward concerning the mechanism of vasovagal syncope is that the vagal afferent fibres are activated during vigorous contractions against a partly empty left ventricle. The aim of the study was to confirm this hypothesis by using 2D echocardiography during a head-up tilt test. The study was carried out on 39 patients (17 male, 22 female, age range 21–64 years), all with a history of recurrent syncope. The patients were examined using a 2D echo to measure the end-diastolic and end-systolic volume before the head-up tilt test after the Westminster protocol (45min/60 grade) and every five minutes after tilting. T patients during head-up tilt test had a positive response and 32 proved negative. A reduction of both the end-diastolic and end-systolic volumes of the left ventricle was noticed. There was no significant difference in the degree of ejection fraction reduction. The difference in ejection fraction reduction between the two groups was similarly non-significant. It was also noticed that the patients with a positive response had more vigorous contractions than those with a negative test. The decision was therefore taken to use a different parameter for the left ventricle contraction, namely the LV posterior wall slope. As this parameter is partly dependent on time, its use in confirming the extremely vigorous nature of the contractions was considered appropriate. Only 6 patients were tested using this parameter. A tendency towards greater left ventricle posterior wall slope values, both before and during tilting was noticed in the group of patients with vasovagal reaction. Our data shows that vigorous contraction is probably less responsible for vasovagal syncope release than left ventricle volume reduction

Computational Studies of the Mechanical Stability for Single-Strand Break DNA.

The stability of DNA is crucial for the existence of most living organisms. Even a single DNA break can lead to serious problems, including cell death. In this work the position specificity of single strand breaks (SSB) and the stability of short DNA fragments of various lengths and sequence repetitions (d(AT)30, d(ATGC)15, d(GC)30, d(TTAGG)12, d(TTAGGG)10, and d(TTTAGGG)9 with SSBs and d(GC) with 2-60 repetitions without SSBs) were examined, by performing a series of steered molecular dynamics simulations using the coarse-grained NARES-2P force field. Our results show that the stability of DNA with a SSB strongly depends on the position of the break, and that the minimum length of DNA required for stability is sequence dependent. d(GC)30 with an SSB in position x was found to be less resistant to stretching than d(GC) x without SSB, where x is the number of d(GC) repetitions. DNA sequences with longer repeated fragments (such as telomeres) exhibit greater stability in the presence of breaks positioned at the beginning of the chain, which could constitute a cellular defense mechanism against DNA damage

Miejsca pamięci i miejsca zapomnienia. Interdyscyplinarne badania na Jurze Krakowsko-Częstochowskiej. Raport z badań. Tom 1. Wprowadzenie metodologiczne

Publikacja powstała w ramach projektu badawczego „Miejsca pamięci i zapomnienia. Interdyscyplinarne badania północnych terenów Jury Krakowsko-Częstochowskiej”.Publikacja jest pierwszym tomem serii raportów, wydanych w formie elektronicznej, prezentujących rezultaty działań podjętych w projekcie badawczym „Miejsca pamięci i zapomnienia. Badania interdyscyplinarne północnych terenów Jury Krakowsko-Częstochowskiej”, realizowanym na Wydziale Filozoficzno-Historycznym Uniwersytetu Łódzkiego w latach 2014–2019 w ramach Narodowego Programu Rozwoju Humanistyki Ministerstwa Nauki i Szkolnictwa Wyższego. Tom zawiera propozycję interdyscyplinarnej metodologii oraz zestawu etnograficznych i archeologicznych procedur badawczych powiązanych z ustaleniami z zakresu historii i historii sztuki. W kolejnych raportach zaprezentowane zostaną wyniki badań przeprowadzonych w pięciu gminach powiatu częstochowskiego: Mstów (tom 2), Olsztyn (tom 3), Janów (tom 4), Lelów (tom 5) i Przyrów (tom 6). Całość badań zostanie zwieńczona w oddzielnym opracowaniu wydanym drukiem, zawierającym m.in. wieloaspektowe rozważania dotyczące objętych projektem gmin.Narodowy Program Rozwoju Humanistyki - Ministerstwo Nauki i Szkolnictwa Wyższeg

Anterior region of the atrioventricular perinodal area in relation to radiofrequency ablation procedures

Atrioventricular nodal reentry tachycardia base on reentry circulation in nodal-perinodal area. The radical treatment of choice is radiofrequency ablation. Procedure approached from the anterior-superior (fast) region sufficient a few seconds of energy delivery for success, however this can result in A-V block. The possibility that arrhythmias substrate may lie very superficially (success of ablation) and damage the normal structures (complication) in the perinodal region must be considered. In order to confirm this hypothesis we examined the autopsy material of 100 normal hearts, both sexes from 18 to 105 years of age (control) and 50 hearts with A-V total block 45-95 years of age (block). We paid attention to the morphology of the nodal artery (NA), atrial inputs (AI) and transitional inputs (TI). It was observed that NA at the level of the central fibrous body was positioned in 94% in the central and in 6% in the inferior part of Koch&#8217;s triangle. It was removed from the endocardium 3-6 mm in control and 2-5 mm in block group respectively (NS). In the perinodal area we distinguished AI that directly joined the A-V compact node: superficial (right part of the interatrial septum) or deep (left part). The former occurred in 100% of controls and in 80% of block groups (NS), and the latter in 80% of control group and in 34% in block respectively (p < 0.05). The real substrate of arrhythmia in anterior-superior region lies very superficially and far from the conduction tissue; NA in examined hearts was lying deep beneath the endocardium; ablation close to the node could result in A-V block

Wartość diagnostyczna czynnego testu pochyleniowego z zastosowaniem nitrogliceryny

Wstęp: Omdlenia wazowagalne (VVS) stanowią około 30% wszystkich omdleń. Uznaną metodą w diagnostyce tych utrat przytomności jest test pochyleniowy (HUTT), którego czułość waha się od 32% do 74%. Aby ją zwiększyć, stosuje się prowokację farmakologiczną. Do najczęściej stosowanych leków należą izoprenalina i nitrogliceryna. Materiał i metody: Badaniem objęto 157 chorych (99 kobiet i 58 mężczyzn w wieku 13-70 lat) z omdleniami o nieustalonej etiologii oraz 15 zdrowych ochotników. Pionizację pacjenta poprzedzal 30-minutowy okres odpoczynku, po którym następowała pionizacja do kąta 60°. Test bierny (bez obciążenia farmakologicznego) trwał 60 min (40 pts.) lub 45 min (117 pts.). W wypadku braku przedomdlenia lub omdlenia podawano podjęzykowo 0,25 mg nitrogliceryny i kontynuowano badanie przez kolejnych 20 min. Typ omdlenia rozpoznawano na podstawie klasyfikacji VASIS z 1992 roku (z uwzględnieniem poprawek VASIS z 1999 roku). Wyniki: Na podstawie wyników grupy badanej i kontrolnej oceniono czułość i swoistość HUTT z zastosowaniem nitrogliceryny na 59% i 87%. Odpowiedź fałszywie dodatnia po nitroglicerynie wystąpiła w 8 (5%) przypadkach w grupie badanej i u 1 (7%) chorego z grupy kontrolnej. Ciśnienie tętnicze < 95/65 mm Hg bezpośrednio przed podaniem nitrogliceryny może zwiększać prawdopodobieństwo odpowiedzi fałszywie dodatniej. W grupie pacjentów diagnozowanych za pomocą biernego i czynnego HUTT występowały kolejno poszczególne typy omdleń wazowagalnych: typ 1 - 58% i 60%, 2A -18% i 19%, 2B -11 % i 2%, typ 3 - 13% i 19%. U 7 (6%) chorych po zastosowaniu nitrogliceryny wystąpiły bóle głowy, a u 2 osób (2%) pojawiły się ogniskowe objawy neurologiczne. Wnioski: Zastosowanie nitrogliceryny podanej podjęzykowo w czasie HUTT pozwala zwiększyć czułość badania, przy umiarkowanym zmniejszeniu jego swoistości. W czasie kwalifikacji pacjentów do czynnego testu z użyciem nitrogliceryny należy zachować szczególną ostrożność