Uptake, translocation, weathering and speciation of gold nanoparticles in potato, radish, carrot and lettuce crops.

Extensive use of nanomaterials in agriculture will inevitably lead to their release to the environment in significant loads. Thus, understanding the fate of nanoparticles in the soil-plant environment, and potential presence and consequent implication of nanoparticles in food and feed products, is required. We study plant uptake of gold nanoparticles from soil, and their distribution, translocation and speciation (in terms of particle size change and release of ionic Au) in the different plant tissues of four important crops (potato, radish, carrot and lettuce). Our new analytical protocol and experiments show the feasibility of determining the presence, concentration and distribution of nanoparticles in different plant parts, which differ from plant to plant. Critically, we identify the evident capacity of plants to break down (or substantially change the properties of) nanoparticles in the rhizosphere prior to uptake, as well as the evident capacity of plants to reorganize ionic metals as nanoparticles in their tissues. This could lead to nanoparticle exposure through consumption of crops.

Metazachlor effect on poplar - Pioneer plant species for riparian buffers.

Metazachlor belongs to one of the most used herbicides throughout the world. In order to prevent the contamination of water bodies by such herbicides, the riparian buffers are constructed. The selection of appropriate plant species for this purpose is necessary. In our project, we studied the possibility of grey poplar to uptake and biotransform metazachlor, along with the phytotoxic effect of metazachlor and its metabolites. We used two different models - suspension cultures and poplar regenerants cultivated in vitro. Our results show that the herbicide metazachlor is readily metabolized by both suspension cultures and regenerants to 16 detectable metabolites. The detailed scheme of biotransformation pathway in poplar tissue is presented for the first time. The profile of detected metabolites was approximately the same in poplar cell cultures and regenerants, but the ratio and amounts of particular compounds was significantly different. Generally, the highest concentration (peak area/mg of DW) of all metabolites was present in the roots; the only exception was lactate conjugate (deCl-MZCl-Lact), which accumulated in the cultivation media. Although the plants were not visibly affected by metazachlor or its metabolites, they showed changes in activity of antioxidant enzymes and increased content of phenolic substances, the indicators of stress.

[Thoracoscopic, epicardial ablation of atrial fibrillation using the COBRA Fusion system as the first part of hybrid ablation]. / Thorakoskopická epikardiální ablace fibrilace síní systémem COBRA Fusion jako první cást hybridního výkonu.

INTRODUCTION: Treatment of persistent and long-standing persistent atrial fibrillation is not successfully managed by methods of catheter ablation or pharmacotherapy. Hybrid ablation (i.e. combination of minimally invasive surgical ablation, followed by electrophysiological assessment and subsequent endocardial catheter ablation to complete the entire intended procedure) presents an ever more used and very promising treatment method. METHOD: Patients underwent thoracoscopic ablation of pulmonary veins and posterior wall of the left atrium (the box-lesion) with use of the COBRA Fusion catheter; thoracoscopic occlusion of the left atrial appendage using the AtriClip system was also done in later patients. After 23 months, electrophysiological assessment and catheter ablation followed. In this article we summarize a strategy of the surgical part of the hybrid procedure performed in our centre. We describe the surgery itself (including possible periprocedural complications) and we also present our short-term results, especially with respect to subsequent electrophysiological findings. RESULTS: Data of the first 51 patients were analyzed. The first 25 patients underwent unilateral ablation; the mean time of surgery was 102 min. Subsequent 26 patients underwent the bilateral procedure with the mean surgery time of 160 min. Serious complications included 1 stroke, 1 phrenic nerve palsy and 2 surgical re-explorations for bleeding. After 1 month, 65% of patients showed sinus rhythm. The box-lesion was found complete during electrophysiological assessment in 38% of patients and after catheter ablation, 96% of patients were discharged in sinus rhythm. CONCLUSION: The surgical part of the hybrid procedure with use of the minimally invasive approach and the COBRA Fusion catheter is a well-feasible method with a low number of periprocedural complications. For electrophysiologists, it provides a very good basis for successful completion of the hybrid ablation.Key words: atrial fibrillation hybrid ablation - thoracoscopy catheter ablation electrophysiology assessment.

Biodegradation of airborne acetone/styrene mixtures in a bubble column reactor.

The ability of a bubble column reactor (BCR) to biodegrade a mixture of styrene and acetone vapors was evaluated to determine the factors limiting the process efficiency, with a particular emphasis on the presence of degradation intermediates and oxygen levels. The results obtained under varied loadings and ratios were matched with the dissolved oxygen levels and kinetics of oxygen mass transfer, which was assessed by determination of kLa coefficients. A 1.5-L laboratory-scale BCR was operated under a constant air flow of 1.0 L.min-1, using a defined mixed microbial population as a biocatalyst. Maximum values of elimination capacities/maximum overall specific degradation rates of 75.5 gC.m-3.h-1/0.197 gC.gdw-1.h-1, 66.0 gC.m-3.h-1/0.059 gC.gdw-1.h-1, and 45.8 gC.m-3.h-1/0.027 gC.gdw-1.h-1 were observed for styrene/acetone 2:1, styrene-rich and acetone-rich mixtures, respectively, indicating significant substrate interactions and rate limitation by biological factors. The BCR removed both acetone and styrene near-quantitatively up to a relatively high organic load of 50 g.m-3.h-1. From this point, the removal efficiencies declined under increasing loading rates, accompanied by a significant drop in the dissolved oxygen concentration, showing a process transition to oxygen-limited conditions. However, the relatively efficient pollutant removal from air continued, due to significant oxygen mass transfer, up to a threshold loading rate when the accumulation of acetone and degradation intermediates in the aqueous medium became significant. These observations demonstrate that oxygen availability is the limiting factor for efficient pollutant degradation and that accumulation of intermediates may serve as an indicator of oxygen limitation. Microbial (activated sludge) analyses revealed the presence of amoebae and active nematodes that were not affected by variations in operational conditions.

Metabolism of ibuprofen in higher plants: A model Arabidopsis thaliana cell suspension culture system.

The uptake and metabolism of ibuprofen (IBU) by plants at the cellular level was investigated using a suspension culture of A. thaliana. Almost all IBU added to the medium (200 µM) was metabolized or bound to insoluble structures in 5 days. More than 300 metabolites were determined by liquid chromatography-high resolution mass spectrometry (LC-HRMS) analysis, and most of these are first reported for plants here. Although hydroxylated derivatives formed by oxidation on the isobutyl side chain were the main first-step products of IBU degradation, conjugates of these products with sugar, methyl and amino acid groups were the dominant metabolites in the culture. The main portion of total added IBU (81%) was accumulated in the extractable intracellular pool, whereas the cultivation medium fraction contained only 19%. The amount of the insoluble cell-wall-bound IBU was negligible (0.005% of total IBU).

Study of praziquantel phytoremediation and transformation and its removal in constructed wetland.

Accumulation and/or degradation of Praziquantel (PZQ) in plants were determined using Phragmites australis, both suspension cultures and in vitro cultivated plants. In case of initial PZQ concentration 20mgL-1, 90% was removed from liquid media within 21days. The accumulated PZQ was partly metabolized, twenty one compounds being identified, products of both Phase I and II of detoxification metabolism. Laboratory results were confirmed in real scale using the constructed wetland (CW), where PZQ (500mg in total) was completely removed until the first purification pond. This result offers a promising possibility to use CW for PZQ removal from agricultural as well as domestic waste-waters.

Hereditary spherocytosis in a patient undergoing coronary artery bypass grafting with cardiopulmonary bypass--a case report.

Hereditary spherocytosis is a genetically determined abnormality of red blood cells. It is the most common cause of inherited haemolysis in Europe and North America within the Caucasian population. We document a patient who underwent an aortocoronary bypass procedure on cardiopulmonary bypass. In view of the uncertain tolerance of the abnormal red cells in hereditary spherocytosis to cardiopulmonary bypass, we reviewed the patient's chart and analyzed recorded values of these parameters: free plasma haemoglobin, renal parameters, cystatin C, bilirubin, liver tests, urine samples. From the results, we can see that slight haemolysis-elevated bilirubin in the blood sample and elevated bilirubin and urobilinogen in the urine sample occurred on the first postoperative day. The levels of these parameters slowly decreased during the next postoperative days. There was no real clinical effect of this haemolysis on renal functions.

Increase in plasma free haemoglobin during cardiopulmonary bypass in heart valve surgery: assessment of renal dysfunction by RIFLE classification.

Heart valve surgery carries a high risk of renal insufficiency as an independent risk factor due to prolonged cardiopulmonary bypass. Multiple causes of cardiopulmonary bypass-associated renal damage have been described, and haemoglobin-induced renal injury is presently being investigated. Forty-three patients scheduled for heart valve surgery (mostly combined) were enrolled in the prospective study. Plasma free haemoglobin (PFH) levels were evaluated by photocolorimetric measurement at the start of procedures (t(0)) and before the end of extracorporeal circulation (t(1)). A statistically significant increase in PFH levels during cardiopulmonary bypass was detected [median values (interquartile range) - t(0): 62.0 (53.4) mg/L, t(1): 320.4 (352.2) mg/L], P < 0.001. A significant regression relationship between the duration of cardiopulmonary bypass and the increased PFH was found (Spearman's correlation coefficient 0.628, P < 0.001). In some elderly patients, the tendency towards a high release of PFH during cardiopulmonary bypass was more pronounced, but the overall association between age and PFH levels was of borderline significance (P = 0.077). The correlation between PFH and post-operative serum creatinine was low and non-significant, but the latter correlated highly with the pre-operative serum creatinine values (Spearman's correlation coefficient reached values of 0.6-0.7, P < 0.001). Patients were classified according to the Risk of renal failure, Injury to the kidney, Failure of kidney function, Loss of kidney function and End-stage renal failure (RIFLE) classification for acute renal dysfunction during post-operative days 1 - 4; the influence of PFH levels at t(1) on the consequent RIFLE classification was not proven (P=0.648), but 4 patients in the Injury category had shown a higher median value of PFH (433.6 mg/L) in comparison with the others (29 patients with no acute renal dysfunction - 313.7 mg/L, 10 patients at Risk - 330.1 mg/L).

One-day kinetics of myocardial engraftment after intracoronary injection of bone marrow mononuclear cells in patients with acute and chronic myocardial infarction.

OBJECTIVE: To investigate the kinetics of myocardial engraftment of bone marrow-derived mononuclear cells (BMNCs) after intracoronary injection using 99mTc-d,l-hexamethylpropylene amine oxime (99mTc-HMPAO) nuclear imaging in patients with acute and chronic anterior myocardial infarction. DESIGN: Nuclear imaging-derived tracking of BMNCs at 2 and 20 h after injection in the left anterior descending (LAD) coronary artery. SETTING: Academical cardiocentre. PATIENTS: Five patients with acute (mean (SD) age 58 (11) years; ejection fraction range 33-45%) and five patients with chronic (mean (SD) age 50 (6) years; ejection fraction range 28-34%) anterior myocardial infarction. INTERVENTIONS: A total of 24.2 x 10(8)-57.0 x 10(8) BMNCs (20% labelled with 700-1000 MBq 99mTc-HMPAO) were injected in the LAD coronary artery. RESULTS: At 2 h after BMNC injection, myocardial activity was observed in all patients with acute (range 1.31-5.10%) and in all but one patient with chronic infarction (range 1.10-3.0%). At 20 h, myocardial engraftment was noted only in three patients with acute myocardial infarction, whereas no myocardial activity was noted in any patient with chronic infarction. CONCLUSIONS: Engraftment of BMNCs shows dynamic changes within the first 20 h after intracoronary injection. Persistent myocardial engraftment was noted only in a subset of patients with acute myocardial infarction.

Use of recombinant factor VIIa for emergency reversal of anticoagulation.

CONTEXT: There is limited data regarding the use of activated recombinant factor VII (rFVIIa) in anticoagulated patients requiring reversal. AIMS: To identify and describe characteristics of subjects who received rFVIIa as part of emergency treatment aimed at improving hemostasis. SETTINGS AND DESIGN: Data was obtained from an international peer-reviewed registry haemostasis.com. This registry contains data reported by physicians, who had elected to use rFVIIa to control bleeding in an emergency clinical situation. The contributors' approval for inclusion in the study was obtained and they were requested to validate and update information. MATERIALS AND METHODS: Database review of cases receiving rFVIIa to manage bleeding coherent with the use of anticoagulant therapy. STATISTICAL ANALYSIS: The Wilcoxon signed rank test was used to compare requirements for blood products and crystalloids/colloids during the 24h preceding and following rFVIIa administration, as well as changes in the levels of clotting factors during that period. RESULTS: Eighteen patients were treated with rFVIIa (median dose: 87.35 microg/kg; range: 20.0-106.0 microg/kg) for bleeding. Anticoagulants requiring reversal included low-molecular-weight heparin (n = 6), unfractionated heparin (n =8), coumarin (n =3) and warfarin (n=1). All patients had failed to respond to traditional antidotes and blood products. Following administration, bleeding stopped in 10, markedly decreased in five and slowed in the remaining three. Amongst 12/16 patients, a response was observed within 2.0 h of first administration. The requirement for blood products and crystalloids/colloids decreased ( P < 0.05) after rFVIIa administration. rFVIIa was well tolerated. CONCLUSIONS: rFVIIa may play a role in control of untoward bleeding in subjects receiving anticoagulation therapy.

Degradation of 2,4,6-trinitrotoluene by selected helophytes.

Four emergent plants (helophytes, synonyms emersion macrophytes, marsh plants, etc.) Phragmites australis, Juncus glaucus, Carex gracillis and Typha latifolia were successfully used for degradation of TNT (2,4,6-trinitrotoluene) under in vitro conditions. The plants took up and transformed more than 90% of TNT from the medium within ten days of cultivation. The most efficient species was Ph. australis which took up 98% of TNT within ten days. The first stable degradation products 4-amino-2,6-dinitrotoluene (4-ADNT) and 2-amino-4,6-dinitrotoluene (2-ADNT) were identified and analysed during the cultivation period. [14C] TNT was used for the detection of TNT degradation products and their compartmentalization in plant tissues after two weeks of cultivation. Forty one percent of 14C was detected as insoluble or bound in cell structures: 34% in roots and 8% in the aerial parts. These results open the perspective of using the above-mentioned plants for the remediation of TNT contaminated waters.

Polyethylene glycol and abscisic acid improve maturation and regeneration of Panax ginseng somatic embryos.

Embryogenic culture was initiated from mature zygotic embryos of Panax ginseng. Multiple somatic embryos formed and proliferated on Murashige and Skoog medium supplemented with 2,4-dichlorophenoxyacetic acid (2.26 microM) and kinetin (0.046 microM). Mature as well as immature somatic embryos grew into plantlets lacking roots on the same media. Histomorphological analysis of somatic embryos treated with abscisic acid (ABA) and polyethylene glycol (PEG 4000) showed a slight improvement in the root meristem organization of torpedo-stage embryos (embryos were more compact and their cells exhibited a lower degree of vacuolation). Shoot regeneration of non-treated somatic embryos was 31% while that for somatic embryos treated with PEG 4000 and ABA was 70%. Moreover, 75% of plants regenerated from PEG- and ABA-treated embryos formed roots while plants from non-treated embryos did not form roots.

Tranexamic acid reduces bleeding after off-pump coronary artery bypass grafting.

AIM: To assess the ability of tranexamic acid, compared with an untreated control group, to decrease bleeding and transfusion requirements in patients undergoing coronary artery bypass grafting on the beating heart. METHODS: Forty-nine randomly selected patients were enrolled to elective coronary artery bypass grafting without the use of cardiopulmonary bypass. Of these, 23 received tranexamic acid (bolus of 1 g before surgical incision, followed by infusion 200 mg/hour during surgery) and 26 patients were enrolled into a control group. Preoperative hematological variables, postoperative blood loss at 4 and 24 hours, transfusion requirements of packed red blood cells,and postoperative thrombotic events such as a myocardial infarction, stroke and pulmonary embolism were recorded. RESULTS: The two groups were similar in terms of patients' characteristics. Postoperative bleeding was significantly lower in the tranexamic acid group compared with the control group (median [25th-75th percentiles]): 115 [92-148] vs 230 [170-260] mL at 4 hours, p<0.001; 420 [330-523] vs 550 [500-650] mL at 24 hours, p<0.01). Transfusion requirements were lower in the tranexamic acid group compared with the control group (RBC 9% vs 28%), but the difference was not statistically significant. Treatment with tranexamic acid was not associated with a higher incidence of myocardial ischemia or other thrombotic events. CONCLUSION: Tranexamic acid reduces postoperative blood loss after coronary artery bypass grafting on the beating heart. Evaluation of transfusion requirements warrants further study.

Screening of some Siberian medicinal plants for antimicrobial activity.

The antimicrobial activity of crude ethanolic extracts of 16 Siberian medicinal plants was tested against five species of microorganisms: Bacillus cereus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. Of the 16 plants tested, 12 showed antimicrobial activity against one or more species of microorganisms. The most active antimicrobial plants were Bergenia crassifolia, Chelidonium majus, Rhaponticum carthamoides, Sanguisorba officinalis, and Tussilago farfara.

[Acute abdomen after cardiac surgery]. / Náhlé príhody brisní po kardiochirurgických výkonech.

Acute abdomen after cardiosurgery accounts for a minor group of complications, however, they are associated with a high mortality and morbidity. In 2001 in the authors department 940 cardiac operations were performed. In four patients (0.43%) during the early postoperative period acute abdomen developed which called for urgent surgical intervention. Two patients died. Only early diagnosis and subsequent urgent laparotomy can have a positive impact on the prognosis of this group of patients.

Thoracic epidural anesthesia for off-pump coronary artery bypass without intubation.

Thoracic epidural anesthesia without intubation was used in 10 patients undergoing off-pump coronary artery reconstruction performed through median sternotomy. Considering the preoperative finding of impaired pulmonary function, all were moderate-risk patients for surgery using conventional general anesthesia with intubation. All patients had an uneventful postoperative course. In indicated cases, we regard thoracic epidural anesthesia as a suitable method again modifying the term "minimally invasive" in cardiac surgery.

[Less invasive approaches in surgical treatment of aortic valve defects]. / Méne invazivní prístupy v chirurgické lécbe aortálních chlopenních vad.

Longitudinal median sternotomy is even nowadays the standard approach to operations of the aortal valve. The authors summarize in the submitted paper their experience with operations in 60 patients where replacement of the aortal valve was performed either from a small transverse sternotomy in the second intercostal space or from upper ministernotomy from the jugulum to the fourth (third) intercostal space. One patient died. The low incidence of serious postoperative complications, the rapid rehabilitation of patients and short subsequent period of hospitalization indicate the advantages of this approach. The authors use at present upper ministernotomy as the surgical approach in the majority of operations of the aortal valve.

Two-dimensional fluorescence spectroscopy - a new tool for the determination of plant cell viability.

Two-dimensional fluorescence spectroscopy (2D-FS) has been used as a new method for determining the viability of tobacco cells (Nicotiana tabacum L.). Both horizontal beam geometry and a vertical set-up achieved with bifurcated fibres were tested. The latter arrangement enabled us to avoid the negative effect of cell sedimentation. Incubation of a tobacco BY-2 cell suspension with dimethylsulfoxide (DMSO) (0-10% v/v) resulted in cell samples differing in their viability - from fully viable (0-2% DMSO) to totally non-viable (8-10%DMSO). The validity of determining viability by means of measuring cell esterase activity by 2D-FS using fluorescein diacetate as a fluorogenic substrate was verified by comparison with microscopic evaluation of fluorescein fluorescence as well as with the routinely adopted trypan blue exclusion test.

Production of taxanes in a bioreactor by Taxus baccata cells.

In a suspension culture of Taxus baccata L. cultivated in a liquid medium according to Ericksson in a 6.21 bioreactor paclitaxel and 8 of its analogues were identified.

[Aortocoronary bypass without extracorporeal circulation]. / Aortokoronární bypass bez pouzití mimotelního obehu.

Extracorporeal circulation is nowadays part of the standard technique of aortocoronary reconstruction. The authors summarize in their paper their experience with operations in 45 patients where an aortocoronary bypass was made on the beating heart without the use of extracorporeal circulation. None of the patients died. The incidence of postoperative complications was low. Rapid rehabilitation of the patients and a shorter period of hospitalization makes this method an alternative standard technique of aortocoronary reconstruction.