Glucocorticoid receptor expression and binding capacity in patients with burn injury.

BACKGROUND: Burn injuries are associated with strong inflammation and risk of secondary sepsis which both may affect the function of the glucocorticoid receptor (GR). The aim of this study was to determine GR expression and binding capacity in leucocytes from patients admitted to a tertiary burn center. METHODS: Blood was sampled from 13 patients on admission and days 7, 14 and 21, and once from 16 healthy subjects. Patients were grouped according to the extent of burn and to any sepsis on day 7. Expression and binding capacity of GR were determined as arbitrary units using flow cytometry. RESULTS: GR expression and binding capacity were increased compared to healthy subjects in most circulating leucocyte subsets on admission irrespective of burn size. Patients with sepsis on day 7 displayed increased GR expression in T lymphocytes (51.8%, P < 0.01) compared to admission. There was a negative correlation between GR binding capacity in neutrophils and burn size after 14 days (P < 0.05). CONCLUSIONS: GR expression and binding capacity are increased in most types of circulating leucocytes of severely burned patients on their admission to specialized burn care. If sepsis is present after 1 week, it is associated with higher GR expression in T lymphocytes and NK cells.

Hyperglycaemia increases S100ß after short experimental cardiac arrest.

BACKGROUND: Hyperglycaemia is associated with aggravated ischaemic brain injury. The main objective of this study was to investigate the effects on cerebral perfusion of 5 min of cardiac arrest during hyperglycaemia and normoglycaemia. METHODS: Twenty triple-breed pigs (weight: 22-29 kg) were randomised and clamped at blood glucose levels of 8.5-10 mM [high (H)] or 4-5.5 mM [normal (N)] and thereafter subjected to alternating current-induced 5 min-cardiac arrest followed by 8 min of cardiopulmonary resuscitation and direct current shock to restore spontaneous circulation. RESULTS: Haemodynamics, laser Doppler measurements and regional venous oxygen saturation (HbO2) were monitored, and biochemical markers in blood [S100ß, interleukin (IL)-6 and tumour necrosis factor (TNF)] quantified throughout an observation period of 3 h. The haemodynamics and physiological measurements were similar in the two groups. S100ß increased over the experiment in the H compared with the N group (P < 0.05). IL-6 and TNF levels increased across the experiment, but no differences were seen between the groups. CONCLUSIONS: The enhanced S100ß response is compatible with increased cerebral injury by hyperglycaemic compared with normoglycaemic 5 min of cardiac arrest and resuscitation. The inflammatory cytokines were similar between groups.

Distant effects of nitric oxide inhalation in lavage-induced lung injury in anaesthetised pigs.

BACKGROUND: Inhalation of nitric oxide (INO) exerts both local and distant effects. INO in healthy pigs causes down-regulation of endogenous nitric oxide (NO) production and vasoconstriction in lung regions not reached by INO, especially in hypoxic regions, which augments hypoxic pulmonary vasoconstriction. In contrast, in pigs with endotoxemia-induced lung injury, INO causes increased NO production in lung regions not reached by INO. The aim of this study was to investigate whether INO exerts distant effects in surfactant-depleted lungs. METHODS: Twelve pigs were anaesthetised, and the left lower lobe (LLL) was separately ventilated. Lavage injury was induced in all lung regions, except the LLL. In six pigs, 40 ppm INO was given to the LLL (INO group), and the effects on endogenous NO production and blood flow in the lavage-injured lung regions were studied. Six pigs served as a control group. NO concentration in exhaled air (ENO), NO synthase (NOS) activity and cyclic guanosine monophosphate (cGMP) in lung tissue, and regional pulmonary blood flow were measured. RESULTS: The calcium (Ca(2+) )-dependent NOS activity was lower (P < 0.05) in the lavage-injured lung regions in the INO group than in the control group. There were no measurable differences between the groups for Ca(2+) -independent NOS activity, cGMP, ENO, or regional pulmonary blood flow. CONCLUSIONS: Regional INO did not increase endogenous NO production in lavage-injured lung regions not directly reached by INO, but instead down-regulated the constitutive calcium-dependent nitric oxide synthase activity, indicating that NO may inhibit its own synthesis.

Predicting QT prolongation in humans during early drug development using hERG inhibition and an anaesthetized guinea-pig model.

BACKGROUND AND PURPOSE: Drug-induced prolongation of the QT interval can lead to torsade de pointes, a life-threatening ventricular arrhythmia. Finding appropriate assays from among the plethora of options available to predict reliably this serious adverse effect in humans remains a challenging issue for the discovery and development of drugs. The purpose of the present study was to develop and verify a reliable and relatively simple approach for assessing, during preclinical development, the propensity of drugs to prolong the QT interval in humans. EXPERIMENTAL APPROACH: Sixteen marketed drugs from various pharmacological classes with a known incidence -- or lack thereof -- of QT prolongation in humans were examined in hERG (human ether a-go-go-related gene) patch-clamp assay and an anaesthetized guinea-pig assay for QT prolongation using specific protocols. Drug concentrations in perfusates from hERG assays and plasma samples from guinea-pigs were determined using liquid chromatography-mass spectrometry. KEY RESULTS: Various pharmacological agents that inhibit hERG currents prolong the QT interval in anaesthetized guinea-pigs in a manner similar to that seen in humans and at comparable drug exposures. Several compounds not associated with QT prolongation in humans failed to prolong the QT interval in this model. CONCLUSIONS AND IMPLICATIONS: Analysis of hERG inhibitory potency in conjunction with drug exposures and QT interval measurements in anaesthetized guinea-pigs can reliably predict, during preclinical drug development, the risk of human QT prolongation. A strategy is proposed for mitigating the risk of QT prolongation of new chemical entities during early lead optimization.

Molecular differentiation of ischemic and valvular heart disease by liquid chromatography/fourier transform ion cyclotron resonance mass spectrometry.

Proteomic patterns of myocardial tissue in different etiologies of heart failure were investigated using a direct analytical approach with High Performance Liquid Chromatography (HPLC)/Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). Right atrial appendages from 20 patients, 10 with hemodynamically significant isolated aortic valve disease and 10 with symptomatic coronary artery disease were collected during elective cardiac surgery. After preparation of tissue samples and tryptic digestion of proteins, the peptide mixture was HPLC-separated and on-line analyzed by electrospray FT-ICR MS. Data obtained from HPLC / FT-ICR MS runs were compared for classification. To extract the classification features, the selection of best individual features was applied and the "nearest mean classifier" was used for the classification of test samples and the sample projection onto classification patterns. The pattern distribution characteristics of aortic and coronary diseases were clearly different. No interference between samples of both disease categories was registered, even if the distribution of unsupervised classified test samples were closer. Samples representing aortic valve disease showed a closer accumulation pattern of spots compared to the samples representing coronary disease, which indicated a more specific protein classification. Through selective identification of specific peptides and protein patterns with FTMS, valvular and coronary heart disease is for the first time clearly distinguished at molecular level. The described methodology could also be feasible in search for specific biomarkers in plasma or serum for diagnostic purposes.

Antibacterial activity of human prostasomes.

BACKGROUND: Prostasomes are prostate-derived organelles in semen exhibiting pluripotent properties. The present study deals with their possible antibacterial effects. METHODS: Antibacterial activity was assessed by growth inhibition of bacteria in an incubation medium containing prostasomes, after which the incubate was inoculated on cystine lactose electrolyte deficient agar (CLED) plates. In cases involving Bacillus megaterium, the effects were also documented ultrastructurally with scanning electron microscopy and atomic force microscopy. RESULTS: A dose-dependent growth inhibition was apparent, and a complete inhibition of growth was seen at a prostasome protein concentration of 30 microg/ml with Bacillus megaterium. Ultrastructurally, increasingly irregular contours and a loosening of the smooth surface were observed, combined with a fragmentation of the bacteria. Among 9 other bacterial strains tested, a complete growth inhibition by prostasomes was attained in 3 strains, while the other 6 were unaffected. CONCLUSIONS: Our data suggest that prostasomes, or prostasome-derived proteins, are responsible for the antibacterial effects on Bacillus megaterium and some other bacterial strains. The results may serve as a basis of development of a new class of antibacterial drugs.