Discrete-time feedback stabilization

This paper presents an algorithm for designing dynamic compensator for infinitedimensional systems with bounded input and bounded output operators using finite dimensional approximation. The proposed method was then implemented in order to find the control function for thin rod heating process. The optimal sampling time was found depending on discrete output measurements

Statement by a Working Group conceived by the Polish National Consultants in Cardiology and Neurology addressing the use of implantable cardiac monitors in patients after ischaemic embolic stroke of undetermined source

Introduction. Stroke remains one of the main causes of death and the most common cause of long-term disability in adults. Embolic strokes of undetermined source (ESUS) amount to a significant proportion of all ischaemic strokes. Detection of atrial fibrillation (AF) in this group of patients would allow for a major therapeutic decision to switch from antiplatelets to oral anticoagulants and therefore significantly reduce the risk of recurrence. State of the Art. Current technology allows long-term continuous ECG monitoring with different systems, including implantable cardiac monitors (ICM). However, in Poland lack of reimbursement does not allow their use in everyday clinical practice. Clinical Implications. This is a statement by a Working Group conceived by the Polish National Consultants in Cardiology and Neurology addressing the use of ICM in patients after ischaemic embolic strokes of undetermined source. The aim was to develop reasonable and comprehensive guidance on how to select and manage candidates for ICM in order to obtain the maximum benefit for Polish public health. Future Directions. This expert opinion is not intended as a guideline but it provides advice as to how to optimise the potential use of ICM in patients after ESUS in the Polish setting

Transvenous Lead Extraction in Patients with Cardiac Implantable Device: The Impact of Systemic and Local Infection on Clinical Outcomes. An ESC‐EHRA ELECTRa (European Lead Extraction Controlled) Registry Substudy

Background: Infections of cardiac implantable devices (CIEDI) have poor outcomes despite improvement in lead extraction (TLE) procedures. Methods: To explore the influence of CIEDI on the outcomes of TLE and the differences between patients with systemic (Sy) vs. local (Lo) CIEDI, we performed a sub‐analysis of the EORP ELECTRa (European Lead Extraction ConTRolled) Registry. Results: Among 3555 patients enrolled by 73 centers in 19 Countries, the indication for TLE was CIEDI in 1850: 1170 with Lo‐CIEDI and 680 with Sy‐CIEDI. Patients with CIEDI had a worse in‐hospital prognosis in terms of major complications (3.57% vs. 1.71%; p = 0.0007) and mortality (2.27% vs. 0.49%; p < 0.0001). Sy‐CIEDI was an independent predictor of in‐hospital death (H.R. 2.14; 95%CI 1.06–4.33. p = 0.0345). Patients with Sy‐CIEDI more frequently had an initial CIED implant and a higher prevalence of comorbidities, while subjects with Lo‐CIEDI had a higher prevalence of previous CIED procedures. Time from signs of CIEDI and TLE was longer for Lo‐CIEDI despite a shorter pre‐TLE antibiotic treatment. Conclusions: Patients with CIEDI have a worse in‐hospital prognosis after TLE, especially for patients with Sy‐CIEDI. These results raise the suspicion that in a relevant group of patients CIEDI can be systemic from the beginning without progression from Lo‐CIEDI. Future research is needed to characterize this subgroup of patients

Structural bases of peptidoglycan recognition by lysostaphin SH3b domain.

Staphylococcus simulans lysostaphin cleaves pentaglycine cross-bridges between stem peptides in the peptidoglycan of susceptible staphylococci, including S. aureus. This enzyme consists of an N-terminal catalytic domain and a cell wall binding domain (SH3b), which anchors the protein to peptidoglycan. Although structures of SH3bs from lysostaphin are available, the binding modes of peptidoglycan to these domains are still unclear. We have solved the crystal structure of the lysostaphin SH3b domain in complex with a pentaglycine peptide representing the peptidoglycan cross-bridge. The structure identifies a groove between β1 and β2 strands as the pentaglycine binding site. The structure suggests that pentaglycine specificity of the SH3b arises partially directly by steric exclusion of Cβ atoms in the ligand and partially indirectly due to the selection of main chain conformations that are easily accessible for glycine, but not other amino acid residues. We have revealed further interactions of SH3b with the stem peptides with the support of bioinformatics tools. Based on the structural data we have attempted engineering of the domain specificity and have investigated the relevance of the introduced substitutions on the domain binding and specificity, also in the contexts of the mature lysostaphin and of its bacteriolytic activity

Implantacja stentów wydzielających rapamycynę (Sirolimus) u chorych ze zwiększonym ryzykiem restenozy. Roczna obserwacja 100 pacjentów

Wstęp: Występowanie restenozy w stencie po zabiegach angioplastyki wieńcowej stanowi nadal istotny problem kardiologii interwencyjnej. Wprowadzone niedawno stenty wydzielające leki antyproliferacyjne budzą nadzieję na szybkie uporanie się z tym problemem. Celem pracy jest ocena wczesnych i odległych wyników implantacji stentów wydzielających rapamycynę u chorych ze zwiększonym ryzykiem restenozy. Materiał i metody: Stenty Cypher™ firmy Cordis (Johnson & Johnson) implantowano 107 pacjentom ze stabilną lub niestabilną dławicą, po wcześniejszym, kilkudniowym przygotowaniu tienopirydynami. Oceniano wyniki bezpośrednie zabiegu oraz przeprowadzono obserwację kliniczną pacjentów po 30 dniach, a także po minimum 9 miesiącach. U 71 osób wykonano kontrolną koronarografię. Wyniki: W pierwszych 30 dniach jedynym powikłaniem było wystąpienie zawału serca bez załamka Q (bezobjawowy wzrost stężenia enzymów 3-krotnie przewyższający normę) w okresie okołozabiegowym u 3 pacjentów. W obserwacji odległej nie stwierdzono zgonów, u 3 chorych wystąpił zawał serca z załamkiem Q, u 2 z nich prawdopodobnie na skutek późnej zakrzepicy w stencie. Czterech pacjentów wymagało ponownej rewaskularyzacji leczonego naczynia. Spośród 71 chorych, u których wykonano kontrolną koronarografię, nie zaobserwowano restenozy w stencie, a w jednym przypadku stwierdzono restenozę w leczonym segmencie. Wnioski: Implantacja stentów wydzielających rapamycynę jest bezpiecznym i bardzo skutecznym sposobem leczenia zwężeń naczyń wieńcowych u chorych ze zwiększonym ryzykiem wystąpienia restenozy. (Folia Cardiol. 2004; 11: 505–511

Implantacja stentów wydzielających rapamycynę (Sirolimus) u chorych ze zwiększonym ryzykiem restenozy. Roczna obserwacja 100 pacjentów

Wstęp: Występowanie restenozy w stencie po zabiegach angioplastyki wieńcowej stanowi nadal istotny problem kardiologii interwencyjnej. Wprowadzone niedawno stenty wydzielające leki antyproliferacyjne budzą nadzieję na szybkie uporanie się z tym problemem. Celem pracy jest ocena wczesnych i odległych wyników implantacji stentów wydzielających rapamycynę u chorych ze zwiększonym ryzykiem restenozy. Materiał i metody: Stenty Cypher™ firmy Cordis (Johnson & Johnson) implantowano 107 pacjentom ze stabilną lub niestabilną dławicą, po wcześniejszym, kilkudniowym przygotowaniu tienopirydynami. Oceniano wyniki bezpośrednie zabiegu oraz przeprowadzono obserwację kliniczną pacjentów po 30 dniach, a także po minimum 9 miesiącach. U 71 osób wykonano kontrolną koronarografię. Wyniki: W pierwszych 30 dniach jedynym powikłaniem było wystąpienie zawału serca bez załamka Q (bezobjawowy wzrost stężenia enzymów 3-krotnie przewyższający normę) w okresie okołozabiegowym u 3 pacjentów. W obserwacji odległej nie stwierdzono zgonów, u 3 chorych wystąpił zawał serca z załamkiem Q, u 2 z nich prawdopodobnie na skutek późnej zakrzepicy w stencie. Czterech pacjentów wymagało ponownej rewaskularyzacji leczonego naczynia. Spośród 71 chorych, u których wykonano kontrolną koronarografię, nie zaobserwowano restenozy w stencie, a w jednym przypadku stwierdzono restenozę w leczonym segmencie. Wnioski: Implantacja stentów wydzielających rapamycynę jest bezpiecznym i bardzo skutecznym sposobem leczenia zwężeń naczyń wieńcowych u chorych ze zwiększonym ryzykiem wystąpienia restenozy. (Folia Cardiol. 2004; 11: 505–511

Position of the Polish Cardiac Society on therapeutic targets for LDL cholesterol concentrations in secondary prevention of myocardial infarctions

Cardiovascular diseases account for 43% of deaths in Poland. The COVID-19 pandemic increased the number of cardiovascular deaths by as much as 16.7%. Lipid metabolism disorders are observed in about 20 million Poles. Lipid disorders are usually asymptomatic, they cause a significant increase in the risk of cardiovascular diseases. Up to 20% of patients who experience an acute coronary syndrome (ACS) may experience a recurrence of a cardiovascular event within a year, and up to 40% of these patients may be re-hospitalized. Within 5 years after a myocardial infarction, 18% of patients suffer a second ACS and 13% have got a stroke. Lipid-lowering therapy is an extremely important element of comprehensive management, both in primary and secondary prevention, and its main goal is to prevent or extend the time to the onset of heart or vascular disease and reduce the risk of cardiovascular events. A patient with a history of ACS belongs to the group of a very high risk of a cardiovascular event due to atherosclerosis. In this group of patients, low-density lipoprotein cholesterol levels should be aimed below 55 mg/dl (1.4 mmol/l). Many scientific guidelines define the extreme risk group, which includes not only patients with two cardiovascular events within two years, but also patients with a history of ACS and additional clinical factors: peripheral vascular disease, multivessel disease (multilevel atherosclerosis), or multivessel coronary disease, or familial hypercholesterolemia, or diabetes with at least one additional risk factor: elevated Lp(a) >50 mg/dl or hsCRP >3 mg/l, or chronic kidney disease (eGFR <60 ml/min/1.73 m2). In this group of patients, the LDL-C level should be aimed at below 40 mg/dl (1.0 mmol/l). Achieving therapeutic goals in patients after ACS should occur as soon as possible. For this purpose, a high-dose potent statin should be added to the therapy at the time of diagnosis, and ezetimibe should be added if the goal is not achieved after 4–6 weeks. Combination therapy may be considered in selected patients from the beginning. After 4–6 weeks of combination therapy, if the goal is still not achieved, adding a proprotein convertase subtilisin/kexin type 9 protein inhibitor or inclisiran should be considered. In order to increase compliance with the recommendations, Polish Cardiac Society and Polish Lipid Society propose to attach in the patient’s discharge letter a statement clearly specifying what drugs should be used and what LDL-C values should be achieved. It is necessary to cooperate between the patient and the doctor, to follow the recommendations and take medicines regularly, to achieve and maintain therapeutic goals

Implantable cardioverter-defibrillators in patients with long QT syndrome: a multicentre study

Background: Implantable cardioverter-defibrillator (ICD) therapy has been proven effective in the prevention of sudden cardiac death, but data on outcomes of ICD therapy in the young and otherwise healthy patients with long QT syndrome (LQTS) are limited. Aim: We sought to collect data on appropriate and inappropriate ICD discharges, risk factors, and ICD-related complications. Methods: All LQTS patients implanted with an ICD in 14 centres were investigated. Demographic, clinical, and ICD therapy data were collected. Results: The study included 67 patients (88% female). Median age at ICD implantation was 31 years (12–77 years). ICD indication was based on resuscitated cardiac arrest in 46 patients, syncope in 18 patients, and malignant family history in three patients. During a median follow-up of 48 months, 39 (58%) patients received one or more ICD therapies. Time to first appropriate discharge was up to 55 months. Inappropriate therapies were triggered by fast sinus rhythm, atrial fibrillation, and T-wave oversensing. No predictors of inappropriate shocks were identified. Risk factors for appropriate ICD therapy were: (1) recurrent syncope despite b-blocker treatment before ICD implantation, (2) pacemaker therapy before ICD implantation, (3) single-chamber ICD, and (4) noncompliance to b-blockers. In 38 (57%) patients, at least one complication occurred. Conclusions: ICD therapy is effective in nearly half the patient population; however, the rates of early and late complica­tions are high. Although the number of unnecessary ICD shocks and reimplantation procedures may be lowered by modern programming and increased longevity of newer ICD generators, other adverse events are less likely to be reduced

Two-site recognition of Staphylococcus aureus peptidoglycan by lysostaphin SH3b

Lysostaphin is a bacteriolytic enzyme targeting peptidoglycan, the essential component of the bacterial cell envelope. It displays a very potent and specific activity toward staphylococci, including methicillin-resistant Staphylococcus aureus. Lysostaphin causes rapid cell lysis and disrupts biofilms, and is therefore a therapeutic agent of choice to eradicate staphylococcal infections. The C-terminal SH3b domain of lysostaphin recognizes peptidoglycans containing a pentaglycine crossbridge and has been proposed to drive the preferential digestion of staphylococcal cell walls. Here we elucidate the molecular mechanism underpinning recognition of staphylococcal peptidoglycan by the lysostaphin SH3b domain. We show that the pentaglycine crossbridge and the peptide stem are recognized by two independent binding sites located on opposite sides of the SH3b domain, thereby inducing a clustering of SH3b domains. We propose that this unusual binding mechanism allows synergistic and structurally dynamic recognition of S. aureus peptidoglycan and underpins the potent bacteriolytic activity of this enzyme