A Novel Biosensor for Evaluation of Apoptotic or Necrotic Effects of Nitrogen Dioxide during Acute Pancreatitis in Rat

The direct and accurate estimation of nitric dioxide levels is an extremely laborious and technically demanding procedure in the molecular diagnostics of inflammatory processes. The aim of this work is to demonstrate that a stop-flow technique utilizing a specific spectroscopic biosensor can be used for detection of nanomolar quantities of NO2 in biological milieu. The use of novel compound cis-[Cr(C2O4)(AaraNH2)(OH2)2]+ increases NO2 estimation accuracy by slowing down the rate of NO2 uptake. In this study, an animal model of pancreatitis, where nitrosative stress is induced by either 3g/kg bw or 1.5 g/kg bw dose of l-arginine, was used. Biochemical parameters and morphological characteristics of acute pancreatitis were monitored, specifically assessing pancreatic acinar cell death mode, NO2 generation and cellular glutathione level. The severity of the process correlated positively with NO2 levels in pancreatic acinar cell cytosol samples, and negatively with cellular glutathione levels

Molecular characterization of the PhiKo endolysin from Thermus thermophilus HB27 bacteriophage phiKo and its cryptic lytic peptide RAP-29

IntroductionIn the era of increasing bacterial resistance to antibiotics, new bactericidal substances are sought, and lysins derived from extremophilic organisms have the undoubted advantage of being stable under harsh environmental conditions. The PhiKo endolysin is derived from the phiKo bacteriophage infecting Gram-negative extremophilic bacterium Thermus thermophilus HB27. This enzyme shows similarity to two previously investigated thermostable type-2 amidases, the Ts2631 and Ph2119 from Thermus scotoductus bacteriophages, that revealed high lytic activity not only against thermophiles but also against Gram-negative mesophilic bacteria. Therefore, antibacterial potential of the PhiKo endolysin was investigated in the study presented here.MethodsEnzyme activity was assessed using turbidity reduction assays (TRAs) and antibacterial tests. Differential scanning calorimetry was applied to evaluate protein stability. The Collection of Anti-Microbial Peptides (CAMP) and Antimicrobial Peptide Calculator and Predictor (APD3) were used to predict regions with antimicrobial potential in the PhiKo primary sequence. The minimum inhibitory concentration (MIC) of the RAP-29 synthetic peptide was determined against Gram-positive and Gram-negative selected strains, and mechanism of action was investigated with use of membrane potential sensitive fluorescent dye 3,3′-Dipropylthiacarbocyanine iodide (DiSC3(5)).Results and discussionThe PhiKo endolysin is highly thermostable with melting temperature of 91.70°C. However, despite its lytic effect against such extremophiles as: T. thermophilus, Thermus flavus, Thermus parvatiensis, Thermus scotoductus, and Deinococcus radiodurans, PhiKo showed moderate antibacterial activity against mesophiles. Consequently, its protein sequence was searched for regions with potential antibacterial activity. A highly positively charged region was identified and synthetized (PhiKo105-133). The novel RAP-29 peptide lysed mesophilic strains of staphylococci and Gram-negative bacteria, reducing the number of cells by 3.7–7.1 log units and reaching the minimum inhibitory concentration values in the range of 2–31 μM. This peptide is unstructured in an aqueous solution but forms an α-helix in the presence of detergents. Moreover, it binds lipoteichoic acid and lipopolysaccharide, and causes depolarization of bacterial membranes. The RAP-29 peptide is a promising candidate for combating bacterial pathogens. The existence of this cryptic peptide testifies to a much wider panel of antimicrobial peptides than thought previously

Risk factors knowledge among patients with a history of stroke - preliminary study

Brak wiedzy pacjentów na temat znaczenia czynników ryzyka udarów mózgu jest częstą przyczyną ich bagatelizowania i zaniechania diagnostyki oraz leczenia. Celem pracy była ocena wiedzy na temat czynników ryzyka wśród pacjentów z udarem mózgu. Badaniem objęto grupę 41 mężczyzn z rozpoznanym udarem mózgu lub TIA z nadciśnieniem tętniczym w wywiadzie. Grupę kontrolną stanowiło 32 mężczyzn bez zaburzeń krążenia mózgowego, leczonych uprzednio z powodu nadciśnienia tętniczego w poradni nadciśnieniowej. Pacjenci otrzymali kwestionariusz zawierający 15 pytań oceniających podstawową wiedzę na temat nadciśnienia tętniczego, cukrzycy i stylu życia oraz 1 pytanie dotyczące samooceny posiadanej wiedzy o nadciśnieniu tętniczym. Chorzy z udarem mózgu uzyskali gorszą punktację w badaniu ankietowym niż grupa kontrolna (11,51 &plusmn; 2,5 vs. 12,84 &plusmn; 2,36 pkt, p < 0,05). Prawidłowy zakres wartości ciśnienia tętniczego krwi podało 19% chorych z grupy badanej oraz 75% pacjentów z grupy kontrolnej. Swoją wiedzę jako wystarczającą oceniło 19,5% chorych z udarem i 50% osób bez udaru. Wyniki te sugerują, że podstawowa wiedza na temat czynników ryzyka chorób naczyniowych mózgu jest niższa u pacjentów z nadciśnieniem tętniczym oraz z zaburzeniami krążenia mózgowego niż u osób z nadciśnieniem tętniczym bez udaru mózgu.Lack of knowledge about common risk factors of cerebrovascular disorders could provoke their malcontrol and confer further risk increase. The aim of our study was to assess basic knowledge about risk factors in patients with a history of stroke. We studied 41 hypertensive patients with a neurological event approximately 1 month prior to the study. Thirty two agematched hypertensive males without neurological events from outpatient hypertension clinic served as control group. Both groups were given 15 questions evaluating basic knowledge on hypertension, diabetes, life style and a question concerning self-evaluation of their knowledge. Patients with a history of stroke scored less points during the test than those in the control group (11.51 &plusmn; 2.5 vs. 12.84 &plusmn; 2.36 pts; P < 0.01, max 15 pts). The value of normal blood pressure was known by 75% of patients with hypertension and only by 19.5% of those with stroke and hypertension (P < 0.01). These findings indicate that knowledge about risk factors in patients with a history of stroke is poorer than in a control group

The Araucaria Project: A study of the classical Cepheid in the eclipsing binary system OGLE LMC562.05.9009 in the Large Magellanic Cloud

We present a detailed study of the classical Cepheid in the double-lined, highly eccentric eclipsing binary system OGLE-LMC562.05.9009. The Cepheid is a fundamental mode pulsator with a period of 2.988 days. The orbital period of the system is 1550 days. Using spectroscopic data from three 4-8-m telescopes and photometry spanning 22 years, we were able to derive the dynamical masses and radii of both stars with exquisite accuracy. Both stars in the system are very similar in mass, radius and color, but the companion is a stable, non-pulsating star. The Cepheid is slightly more massive and bigger (M_1 = 3.70 +/- 0.03M_sun, R_1 = 28.6 +/- 0.2R_sun) than its companion (M_2 = 3.60 +/- 0.03M_sun, R_2 = 26.6 +/- 0.2R_sun). Within the observational uncertainties both stars have the same effective temperature of 6030 +/- 150K. Evolutionary tracks place both stars inside the classical Cepheid instability strip, but it is likely that future improved temperature estimates will move the stable giant companion just beyond the red edge of the instability strip. Within current observational and theoretical uncertainties, both stars fit on a 205 Myr isochrone arguing for their common age. From our model, we determine a value of the projection factor of p = 1.37 +/- 0.07 for the Cepheid in the OGLE-LMC562.05.9009 system. This is the second Cepheid for which we could measure its p-factor with high precision directly from the analysis of an eclipsing binary system, which represents an important contribution towards a better calibration of Baade-Wesselink methods of distance determination for Cepheids.Comment: Accepted to be published in Ap

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Naczyniaki u dzieci &#8212; problem interdyscyplinarny

Naczyniaki niemowląt (IHs) stanowią jedną z najczęstszych patologii wieku rozwojowego. Charakterystyczne fazy rozwoju naczyniaka: inicjacji, wzrostu i inwolucji, różnią go od malformacji naczyniowej, która powiększa się proporcjonalnie do wzrostu pacjenta. Olbrzymia większość naczyniaków nie wymaga leczenia. Tylko około 10% z nich ze względu na swe rozmiary, położenie czy obecność powikłań stanowi zagrożenie dla życia lub zdrowia. Leczenie powinno być ustalone indywidualnie przy współpracy pediatry, chirurga, dermatologa, okulisty i laryngologa. Od wielu lat leczeniem pierwszego rzutu pozostaje steroidoterapia: ogólna lub miejscowa. Obiecujące dane z ostatnich lat pozwalają przypuszczać, że steroidoterapia zostanie zastąpiona leczeniem propranololem, które cechuje się niemal 100-procentową skutecznością przy braku poważnych działań niepożądanych. Forum Medycyny Rodzinnej 2011, tom 5, nr 6, 460&#8211;46

On the Effect of pH, Temperature, and Surfactant Structure on Bovine Serum Albumin&ndash;Cationic/Anionic/Nonionic Surfactants Interactions in Cacodylate Buffer&ndash;Fluorescence Quenching Studies Supported by UV Spectrophotometry and CD Spectroscopy

Due to the fact that surfactant molecules are known to alter the structure (and consequently the function) of a protein, protein&ndash;surfactant interactions are very important in the biological, pharmaceutical, and cosmetic industries. Although there are numerous studies on the interactions of albumins with surfactants, the investigations are often performed at fixed environmental conditions and limited to separate surface-active agents and consequently do not present an appropriate comparison between their different types and structures. In the present paper, the interactions between selected cationic, anionic, and nonionic surfactants, namely hexadecylpyridinium chloride (CPC), hexadecyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), polyethylene glycol sorbitan monolaurate, monopalmitate, and monooleate (TWEEN 20, TWEEN 40, and TWEEN 80, respectively) with bovine serum albumin (BSA) were studied qualitatively and quantitatively in an aqueous solution (10 mM cacodylate buffer; pH 5.0 and 7.0) by steady-state fluorescence spectroscopy supported by UV spectrophotometry and CD spectroscopy. Since in the case of all studied systems, the fluorescence intensity of BSA decreased regularly and significantly under the action of the surfactants added, the fluorescence quenching mechanism was analyzed thoroughly with the use of the Stern&ndash;Volmer equation (and its modification) and attributed to the formation of BSA&ndash;surfactant complexes. The binding efficiency and mode of interactions were evaluated among others by the determination, comparison, and discussion of the values of binding (association) constants of the newly formed complexes and the corresponding thermodynamic parameters (&Delta;G, &Delta;H, &Delta;S). Furthermore, the influence of the structure of the chosen surfactants (charge of hydrophilic head and length of hydrophobic chain) as well as different environmental conditions (pH, temperature) on the binding mode and the strength of the interaction has been investigated and elucidated

Membrane structure and interactions of peptide hormones with model lipid bilayers

AbstractIn this work, the behavior of the neurohypophyseal hormones and their selected analogs was studied in the presence of membrane models in an attempt to correlate their activities with a distinct behavior at a level of peptide–lipid interactions. The influence of the peptides studied on the lipid acyl chain order was determined using FTIR spectroscopy. Conformational changes in the peptides upon binding to liposomes were examined using CD spectra. Attempts were also made to determine the binding parameters of the peptides to lipids using isothermal titration calorimetry (ITC). The results show unambiguously that the neurohyphophyseal hormone-like peptides interact with lipids, being a model of a eukaryotic cell membrane. Moreover, hydrophobic interactions between the peptides and liposomes are likely to determine the overall conformation of the peptide, especially below the temperature of the main phase transition (Tm). Thus, the bulky and hydrophobic nature of the residues incorporated into the N-terminal part of neurohyphophyseal hormones is an important factor for both restriction of peptide mobility and the interaction of the analog with biomembrane. In turn, above Tm, the electrostatic interactions become also relevant for the conformation of the acyclic tail of the AVP-like peptides