Promene linearnih i nelinearnih mera nizova RR i QT intervala posle uzimanja piva

BACKGROUND: /Aim. There are only several studies on the acute effect of alcoholic drinks intake on heart rhythm and this phenomenon is still not well understood. We wanted to examine whether linear and nonlinear measures of RR interval and QT interval series could quantify the effect of beer in healthy subjects. Methods. Eighteen young volunteers drank 500 mL of beer (21 g of ethanol). Electrocardiogram (ECG) recordings were taken in supine position: 20 minutes before (relaxation) and 60 minutes after drink intake. The RR interval series and the QT interval series were extracted from ECG and we calculated short-term (α1) and long-term (α2) scaling exponents and sample entropy (SampEn) for both series; low frequency (LF) and high frequency (HF) spectral components from RR interval series and QT variability (QTV). Blood pressure was measured every 10 minutes. Results. It was shown that beer induced changes in variability and correlation properties of these series. Immediate effect of beer intake was detected as a transient increase in the QT variability, heart rate and blood pressure. Delayed effects of beer were shortening of the RR and QT intervals and reduction of the HF spectral component. Beer intake also increased short-term scaling exponent (α1) of the RR time series and long-term scaling exponent (α2) of the QT time series. Conclusion. Our results suggest that acute effects of beer are reduced parasympathetic control of the heart and changed dynamic complexity of the ventricular repolarization.Uvod/Cilj. Akutni efekat uzimanja alkoholnih pića na kardiovaskularne ritmove je fenomen koji još uvek nije dovoljno razjašnjen i u literaturi postoji svega nekoliko radova na tu temu. Cilj rada je bio da se ispita da li se linearnim i nelinearnim merama nizova RR i QT intervala može kvantifikovati akutni efekat male količine piva kod zdravih osoba. Metode. Osamnaest mladih zdravih muškaraca je pilo po 500 mL piva (21 g etanola). Elektrokardiogram (EKG) je beležen u ležećem položaju: 20 minuta pre (u relaksaciji) i 60 minuta neposredno posle uzimanja pića. Iz digitalizovanog zapisa EKG-a izdvojeni su nizovi RR i QT intervala. Iz oba niza smo izračunali kratkodometni (α1) i dugo-dometni skalirajući eksponent (α2), kao i entropiju uzorka (SampEn). Iz nizova RR intervala određene su spektralne komponente niskofrekventnih (LF) i visokofrekventnih (HF) opsega, a iz nizova QT intervala varijabilnost QT intervala (QTV). Krvni pritisak je bio meren svakih 10 minuta. Rezultati. Pokazali smo da pivo menja varijabilnost i korelacione osobine ovih nizova. Neposredni efekat uzimanja piva ogleda se u prolaznim povećanjima QT varijabilnosti, srčane frekvence i krvnog pritiska, a produženi u skraćenju dužine RR i QT intervala i smanjenju spektralne komponente HF. Uzimanje piva je takođe dovelo do porasta kratkodometnog skalirajućeg eksponenta (α1) RR niza i dugodometnog skalirajućeg eksponenta (α2) QT niza. Zaključak. Akutni efekat uzimanja piva je redukovana parasimpatička kontrola srca i izmenjena kompleksnost dinamike ventrikularne repolarizacije

Transplantation-related risk of Toxoplasma gondii infection: the National Reference Laboratory prospective cohort study results

Toksoplazmoza je česta ali kod pacijenata lečenih transplantacijom uglavnom zanemarena i pogrešno dijagnostikovana oportunistička infekcija koja može ugroziti engraftment ali može i evoluirati u životno ugrožavajuću diseminovanu infekciju. Nakon transplantacije, infekcija parazitom Toxoplasma gondii se može razviti kao reaktivacija hronične infekcije ili može biti preneta graftom. Naša osmogodišnja prospektivna studija bila je usmerena na dijagnostiku i monitoring toksoplazmatske infekcije (TI) kod primalaca matičnih ćelija hematopoeze (haematopoietic stem cell transplant, HSCT) u centru koji primenjuje protokol uzdržavanja od profilakse do engraftmenta, i kod primalaca transplantata srca (heart transplant, HT) koji su na kontinuiranoj profilaksi trimetoprim- sulfametoksazolom (TMP-SMX). Cilj nam je bio utvrđivanje incidence TI u ova dva vrlo različita transplantaciona režima, i to pre nego što evoluira u klinički manifestnu, potencijalno fatalnu bolest (Toxoplasma disease, TD). Pre-transplantacioni serološki i qPCR skrining u post-transplantacionom toku zamenjen je redovnim qPCR monitoringom iz uzoraka periferne krvi (peripheral blood, PB) usmerenim na Toxoplasma 529 bp gen. Kod primalaca HSCT, qPCR je rađen jednom nedeljno dok je kod primalaca HT qPCR rađen jednom mesečno prva dva meseca post-HT i potom jednom godišnje. TI je dijagnostikovana na bazi pozitivnog PCR rezultata iz bar jednog uzorka PB. TI je dijagnostikovana kod 21/104 (20.2%) primalaca HSCT, prevashodno nakon alogene (19/75) i retko nakon autologne HSCT (2/29). Više od 50% slučajeva TI dijagnostikovano je tokom prvog meseca post-HSCT, pre engraftmenta odnosno tokom uzdržavanja od profilakse. Sa druge strane, TI je dijagnostikovana kod 3/37 (8.1%) primalaca HT. Uprkos primeni TMP-SMX, qPCR je postao pozitivan godinu dana posle HT kod dva i dve godine post-HSCT kod trećeg pacijenta. Infekcija je bila preneta graftom kod 2/3 (seronegativni) a reaktivirana kod 1/3 primalaca HT (seropozitivni primalac HT poreklom od seropozitivnog donora). Naši rezultati potvrđuju da je sistemski qPCR monitoring iz uzoraka PB dragocen u dijagnostici TI ne samo kod primalaca HSCT već i kod primalaca solidnih organa, posebno nakon HT. Učestalost qPCR monitoringa se mora adaptirati shodno specifičnostima transplantacionog protokola, pre svega primeni profilakse ali i osnovnoj dijagnozi, na način koji omogućava pravovremenu primenu specifične terapije u svakom slučaju TI.Toxoplasmosis is a common but often neglected and misdiagnosed opportunistic infection in transplant recipients, which can not only compromise the engraftment, but also evolve into life-threatening disseminated infection. Post-transplantation, Toxoplasma gondii infection can develop as a reactivation of chronic infection or could be graft-transmitted. We conducted an eight-year-long prospective study on the diagnosis and monitoring of Toxoplasma infection (TI) in haematopoietic stem cell transplant (HSCT) recipients in a setting that withholds prophylaxis until engraftment, and in heart transplant (HT) recipients on continuous trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis. The objective was to determine the incidence of TI before it evolves into clinical, potentially fatal Toxoplasma disease (TD), in these two very different transplantation settings. Pre-transplantation serological and qPCR screening was followed by post-transplantation peripheral blood (PB)-based qPCR monitoring targeting the Toxoplasma 529 bp gene. In HSCT recipients, qPCR was performed weekly while in HT recipients, qPCR was performed monthly for two months post-HT and then yearly. TI was diagnosed based on a positive PCR result in at least one PB sample. TI was diagnosed in 21/104 (20.2%) HSCT recipients, predominantly after allogeneic (19/75) and rarely after autologous HSCT (2/29). Over 50% of TI cases were diagnosed during the first month post-HSCT, while awaiting engraftment without prophylaxis. On the other hand, TI was diagnosed in 3/37 (8.1%) HT recipients. Regardless of the TMP-SMX prophylaxis, qPCR became positive one year after HT in two and two years post-HSCT in third patient. Infection was graft-transmitted in 2/3 (seronegative) and reactivated in 1/3 OHT (seropositive recipient of a seropositive donor’s heart transplant). The presented results show that systematic PB-based qPCR monitoring is a valuable resource for the diagnosis of TI not only in HSCT but also in solid organ recipients, especially after HT. Frequency of qPCR monitoring should be adjusted according to the specificity of the transplantation setting, especially in terms of prophylaxis but also an underlying diagnosis, in a manner allowing for prompt introduction of specific treatment in each case of TI

Case report of an infant with severe vitamin D deficiency rickets manifested as hypocalcemic seizures

Introduction. Hypocalcemic seizures are uncommon in the post-neonatal period. We report an infant with hypocalcemic seizures caused by severe deficiency of vitamin D. Case Outline. A five-month-old male infant was admitted to hospital in March 2013 with recurrent generalized afebrile seizures resistant to clonazepam therapy. At the clinical examination, the infant showed characteristic rachitic signs, so that after a blood sample was taken for laboratory testing, the infant was given infusion of 2 ml/kg of 10% of calcium gluconate at a rate of 0.5 ml/min. The treatment resulted in immediate termination of seizures and normalization of the consciousness of the infant. Blood sample analysis showed extremely low levels of free and total calcium (0.36/1.24 mmol/l) and 25(OH)D (<3 ng/ml), elevated alkaline phosphatase (878 U/l) and parathyroid hormone (283 pg/ml), and low calcium/creatinine ratio (mg/mg) in a portion of urine (0.03), while the levels of serum phosphorus, pH, total protein, albumin and creatinine were within the reference range. Wrist X-ray showed typical signs of rickets. In order to fully stabilize calcium homeostasis, along with 2,000 IU of vitamin D3 daily and standard cow’s milk formula, calcium gluconate (80 mg/kg daily) was given orally over a period of two weeks. The treatment resulted in complete stabilization of the infant’s condition and rapid improvement in laboratory, radiological and clinical findings of rickets. Conclusion. Generalized convulsions in the afebrile infant represent a serious and etiopathogenically very heterogeneous problem. Extremely rare, as in the case of our patient, it may be due to severe hypocalcemia caused by a deficiency of vitamin D

An improved design of optical sensor for long-term measurement of arterial blood flow waveform

We present here the improved design and development of optical sensor for non-invasive measurements of arterial blood flow waveform. The sensor is based on a physical principle of reflective photoplethysmography (PPG). As the light source we used serially connected infrared diodes whereas NPN silicon phototransistors were used as light detectors. The electronic components were molded into square package and poured with silicone. Such preparation produced an elastic superficies that allowed excellent attachment of the sensor on the skins surface. Moreover, a serial connection of infrared diodes and phototransistors completely eliminated signal artifacts caused by minor muscle contractions. The sensor recording performances were examined at the photoplethysmographic sites on three different arteries; the commune carotid, femoral and radial and, on each site the sensor demonstrated remarkable capability to make a consistent, reproducible measurements. Because of the advantageous physical and electrical properties, the new sensor is suitable for various cardiovascular diagnostics procedures, especially when long-term measurements of arterial blood flow waveform are required, for monitoring of different parameters in cardiovascular units and for research