Analysis of risk factors and outcomes of Clostridium difficile infection.

INTRODUCTION: Clostridium difficile (C. difficile) is a Gram-positive, anaerobic rod-shaped bacteria, widely spread in the human environment. In the last decade, the frequency and severity of Clostridium difficile infection (CDI) have been increasing, making this particular disease one of the most significant nosocomial infections. The aim of our study was an analysis of CDI risk factors, its course and consequences. MATERIALS AND METHODS: Medical documentation of the patients treated for CDI in the University Hospital in Cracow and St Anne's Hospital in Miechów has been analysed. The analysis focused on epidemiological data, blood parameters, comorbidities, recurrence rate, and complication rate (deaths included). As part of risk factors analysis, antibiotic use or hospitalisation in a period of 3 months before the episode of infection was considered relevant. Blood tests have been performed using routinely employed, standard methods. RESULTS: We evaluated data of 168 people infected with C. difficile, out of which there were 102 women (61%) and 66 men (39%). The median age of the patients was 74 years for the entire population with 76 years for women and 71 years for male patients. One hundred thirteen people (67%) had been previously hospitalised, and 5 person was a pensioner of a nursing home. 99 people (59%) were treated with antibiotics within 3 months before the first episode of infection. An average length of the hospital stay because of CDI was 11 days. One hundred thirty persons (77%) experienced only 1 episode whereas 38 people (23%) had more than 1 episode of infection. The person with the largest number of recurrences had 9 of them. CONCLUSIONS: The development of CDI is an increasing problem in a group of hospitalised persons, particularly of an old age. The general use of beta-lactam antibiotics is the cause of a larger number of infections with C. difficile. Vast majority of patients have had at least one typical risk factor of CDI.

Dynamic cerebral autoregulation is compromised in ischaemic stroke of undetermined aetiology only in the non-affected hemisphere.

BACKGROUND AND PURPOSE: To assess dynamic cerebral autoregulation (CA) in patients with acute ischaemic stroke of undetermined aetiology, within 72h of stroke onset. MATERIALS AND METHODS: In 6 patients with ischaemic stroke of undetermined aetiology (aged 66±9 years, National Institutes of Health Stroke Scale [NIHSS] score on admission: 4.0, range: 4-11), selected based on screening of 118 consecutive ischaemic stroke patients and in 14 volunteers (aged 62±10 years), we continuously monitored RR intervals (RRI), mean arterial pressure (MAP) by means of photoplethysmography, mean cerebral blood flow velocity (CBFV) using transcranial Doppler ultrasonography, end-tidal CO2 (ETCO2) and respiration during 2-min deep breathing paced at 6min(-1) (0.1Hz). To assess CA, we evaluated the impact of breathing-induced MAP oscillations on fluctuations of CBFV in the hemispheres with stroke, the non-involved hemispheres and randomly selected hemispheres of controls by applying cross-spectral analysis and calculating coherence, transfer function gain (CBFV-MAP gain) and phase shift angle between the two oscillating signals. RESULTS: Phase shift angle between MAP and CBFV oscillations showed values >0 and was significantly reduced in the hemispheres without stroke as compared to controls (0.39±0.95 vs. -1.59±0.33rad, p=0.015), whereas in the hemispheres with stroke, phase shift angle did not differ significantly from that observed in the control hemispheres. Clinical status of stroke patients significantly improved at discharge from the hospital (NIHSS: 2.0, range: 1-8, p=0.028). CONCLUSIONS: During the first days of ischaemic stroke of undetermined aetiology, dynamic cerebral autoregulation is compromised in the non-affected hemisphere, but not in the hemisphere with ischaemic lesion.

Ebola virus disease - pathogenesis, clinical presentation and management.

On March 2014 the WHO notified the outbreak of Ebola virus disease (EVD) in Guinea, and infection quickly spread to another West African countries including Sierra Leone, Liberia and Nigeria. Current outbreak is the largest in the history, since discovery of the virus in 1976. Imported cases and infection among healthcare workers in Europe and United States have elucidated necessity of better education of medical staff. Clinicians must be familiar with clinical picture of EVD, differential diagnosis and therapeutic approach, as rapid diagnosis and prompt introduction of supportive therapy can have a significant impact on the survival.

[Ebola virus disease]. / Ebola virus disease.

Ebola is one of the most virulent zoonotic RNA viruses causing in humans haemorrhagic fever with fatality ratio reaching 90%. During the outbreak of 2014 the number of deaths exceeded 8.000. The "imported" cases reported in Western Europe and USA highlighted the extreme risk of Ebola virus spreading outside the African countries. Thus, haemorrhagic fever outbreak is an international epidemiological problem, also due to the lack of approved prevention and therapeutic strategies. The editorial review article briefly summarizes current knowledge on Ebola virus disease epidemiology, etiology, pathogenesis, clinical presentation, diagnosis as well as possible prevention and treatment.

Real-life study of dual therapy based on dolutegravir and ritonavir-boosted darunavir in HIV-1-infected treatment-experienced patients.

BACKGROUND: Dual therapy based on dolutegravir and ritonavir-boosted darunavir (DTG/DRV/r) is a combination of well-known drugs with a high genetic barrier to HIV resistance. METHOD: A retrospective analysis of all HIV-1 infected treatment-experienced patients who switched to DTG/DRV/r from May 2014 till March 2017 in 4 Polish centres-results of a 48-week treatment. RESULTS: The study group consisted of 59 men and 17 women. Median baseline parameters were: age- 42.7 years, CD4 cells count- 560.5 cells/µl, CD4 cells nadir- 150 cells/µl, number of prior antiretroviral regimens- 3. The introduction of dual therapy was primarily due to virologic failure (30 patients), adverse events on previous regimens (17 patients) and therapy simplification (27 patients). At week 48 the treatment was continued in 70/76 of patients and the median CD4 cells count increased from 560.5 to 641.0 cells/µl. The therapy was discontinued in six patients (1 -virologic failure, 1 -decrease of estimated glomerular filtration rate (eGFR), 1 -myalgia, 3 -lost to follow-up). At week 48 six patients had detectable viremia, but only in one patient viremia was higher than 200 copies/ml. At week 48 the level of serum total cholesterol of the investigated subjects was statistically significantly higher than at the moment of dual therapy introduction (185.8 mg/dl vs. 174.8 mg/dl- p<0.05). However, in patients previously not treated with TDF, there were no changes in lipid parameters during therapy. Proteinuria was observed in 13.2% of patients before the switch to dual therapy and in 7.1% of patients at week 48. CONCLUSIONS: The investigated dual therapy was effective and safe. The observed increase in lipid parameters only concerned the patients who had used a TDF-based regimen prior to analysed dual treatment.

HPLC determination of D-3-hydroxybutyric acid by derivatization with a benzofurazan reagent and fluorescent detection: application in the analysis of human plasma.

A simple and sensitive new method for the determination of D-3-hydroxybutyric acid (D-3-HBA) in human plasma after derivatization is described. The proposed method is based on the reaction of (2S)-2-amino-3-methyl-1-[4-(7-nitro-benzo-2,1,3-oxadiazol-4-yl)-piperazin-1-yl]-butan-1-one (NBD-PZ-Val) with D-3-HBA in the presence of O-(7-azobenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HATU) and N-ethyldiisopropylamine (DIEA) to produce a fluorescent derivative. The formed derivative was monitored fluorimetrically at λ(ex)=489 nm and λ(em)=532 nm. The HPLC analysis was carried out by use of a C18 analytical column (Synergy Hydro 150 mm × 3 mm, i.d., 4 µm) with a binary gradient elution program of 0.1% aqueous trifluoroacetic acid versus methanol. The method showed satisfactory linearity (r(2)=0.9997) in the range from 20 to 500 µmol/L. The limit of detection (LOD) of the method was 7.7 µmol/L, while the limit of quantitation (LOQ) was 25.8 µmol/L. The analytical method was successfully applied to human plasma samples from normal healthy subjects.

The hydrolysis of 4-amino- and 4-dimethylaminobenzene sulfonyl chlorides: an unprecedented case of independence of reactivity from pH.

The reactivity-pH profile for the hydrolysis of 4-aminobenzenesulfonyl chloride 1 has a sigmoid shape with a plateau extending from pH 2 to 11; reactivity of N,N-dimethyaminobenzenesulfonyl chloride 4 is invariant over an even wider pH range (0-14.7). These results, together with the activation data determined at selected pH's for compound 1, are interpreted in light of the occurrence of a reaction mechanism that is dissociative in nature, in which nucleophilic assistance by solvent molecules is given to the amino group of 1 acting as an "internal nucleophile".

A simple, sensitive and efficient assay for the determination of D- and L-lactic acid enantiomers in human plasma by high-performance liquid chromatography.

A new method for the simultaneous determination of D- and L-lactic acid in human plasma has been developed using high-performance liquid chromatography (HPLC) with fluorescence detection. This method is based on the reaction of lactic acid with (2S)-2-amino-3-methyl-1-[4-(7-nitro-benzo-2,1,3-oxadiazol-4-yl)-piperazin-1-yl]-butan-1-one (NBD-PZ-Val) in the presence of O-(7-azobenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HATU) and N-ethyldiisopropylamine (DIEA) to produce fluorescent diastereomeric derivatives that were easily monitored fluorimetrically at λ(ex)=490 nm and λ(em)=532 nm. The separation was achieved by use of a C18 analytical column (Synergy Hydro 150 mm x 3 mm i.d., 4 µm). The calibration curve was linear over the on-column concentration range of 10-200 µmol/L for D-lactic acid and 0.5-4.0 mmol/L for L-lactic acid. The sensitivity was good with a limit of detection of 5.24 µmol/L for D-lactic acid and 0.15 mmol/L for L-lactic acid. The analytical method was successfully applied to human plasma samples from normal healthy subjects.

An improved method for simultaneous analysis of aminothiols in human plasma by high-performance liquid chromatography with fluorescence detection.

Altered levels of aminothiols in biological fluids are thought to be an important risk indicator for several diseases, and reliable methods for the accurate determination of aminothiols concentrations in plasma are thus required. In this paper ammonium 5-bromo-7-fluorobenzo-2-oxa-1,3-diazole-4-sulphonate (SBD-BF) is proposed as a convenient fluorogenic derivatizating reagent for the determination of aminothiols (cysteine, cysteinylglycine, homocysteine and glutathione) by HPLC with fluorescence detection. The reactions of SBD-BF with aminothiols at room temperature are about three-times faster than those of ammonium 7-fluorobenzo-2-oxa-1,3-diazole-4-sulphonate (the most frequently employed reagent) at 60 degrees C. The derivatives of SBD-BF with cysteine, cysteinylglycine, homocysteine and glutathione are easily separated by HPLC and their calibration curves show excellent linearity over the range 0.05-20 micromol/L with excellent r(2) values for all analytes. SBD-BF reacts with thiols under mild conditions, i.e. at 25 degrees C over about 30 min, and is proposed as a suitable fluorogenic reagent for thiol derivatization to be introduced in analytical clinical chemistry. The detection limits of Cys, Cys-Gly, Hcy and GSH at a signal-to-noise ratio of 5 were 0.1 microM for Cys, 0.01 microM for Cys-Gly and Hcy, and 0.02 microM for GSH. Furthermore, validation parameters of the proposed method are quite satisfactory. As an application of this method the determination of thiol derivatives in human plasma was carried out on a number of samples.

Guanidinium groups act as general-acid catalysts in phosphoryl transfer reactions: a two-proton inventory on a model system.

Cleavage/transesterification of phosphodiesters is catalyzed by various acidic groups in solution and with enzymes. General-acid catalysts can transfer protons to the developing phosphorane intermediate, resulting in a monoprotic-monoanionic intermediate, giving the so-called "triester mechanism". Using a proton inventory on a model compound (1) possessing an intramolecular hydrogen bond between a phosphodiester and a guanidinium group, we find that two protons move in the rate-determining step for cleavage/transesterification. In contrast, HPNP shows a single-proton inventory and is a substrate well accepted to react with the movement of only one proton at the transition state. We therefore propose a mechanism for 1 that involves general-acid catalysis by the guanidinium group. This leads one to conclude that other, more acidic groups, such as ammonium and imidazolium, would also act as general-acid catalysts.

Threshold detection using indicator-displacement assays: an application in the analysis of malate in Pinot Noir grapes.

The mathematics for modeling indicator-displacement assay isotherms is presented and contrasted to the classical host-guest binding isotherm. It is shown that the signal response can be tuned to occur closer to 1 equiv of guest relative to a standard binding algorithm. This delay in response leads to a better triggering protocol for threshold detection schemes. The determination of malate in Pinot Noir must was calculated using this new mathematical model, which demonstrates how a color change can be tuned to occur near a desired concentration of analyte.