Preparation of As4S4/Fe3O4 nanosuspensions and in-vitro verification of their anticancer activity.

Multifunctional nanoparticulate systems, especially those used in medicine, are currently of great interest. In this work, the in-vitro anticancer activity of As4S4/Fe3O4 composites dispersed in a water solution of Poloxamer 407 on breast MCF-7 and tongue SCC-25 cancer cells was verified. An increase in apoptotic cells as a consequence of higher caspase activities, a decrease in mitochondrial membrane potential and an accumulation of cells in the G2/M and subG0/G1 phases were detected after treatment with the As4S4/Fe3O4 nanosuspensions. The sterically stabilized nanosuspensions were characterized in relation to their particle size distribution, zeta potential and long-term stability properties. The interaction between the solid and liquid phases of the nanosuspensions was also studied using Fourier transform infrared spectroscopy.

Preparation, properties and anticancer effects of mixed As4S4/ZnS nanoparticles capped by Poloxamer 407.

Arsenic sulfide compounds have a long history of application in a traditional medicine. In recent years, realgar has been studied as a promising drug in cancer treatment. In this study, the arsenic sulfide (As4S4) nanoparticles combined with zinc sulfide (ZnS) ones in different molar ratio have been prepared by a simple mechanochemical route in a planetary mill. The successful synthesis and structural properties were confirmed and followed via X-ray diffraction and high-resolution transmission electron microscopy measurements. The morphology of the particles was studied via scanning electron microscopy and transmission electron microscopy methods and the presence of nanocrystallites was verified. For biological tests, the prepared As4S4/ZnS nanoparticles were further milled in a circulation mill in a water solution of Poloxamer 407 (0.5wt%), in order to cover the particles with this biocompatible copolymer and to obtain stable nanosuspensions with unimodal distribution. The average size of the particles in the nanosuspensions (~120nm) was determined by photon cross-correlation spectroscopy method. Stability of the nanosuspensions was determined via particle size distribution and zeta potential measurements, confirming no physico-chemical changes for several months. Interestingly, with the increasing amount of ZnS in the sample, the stability was improved. The anti-cancer effects were tested on two melanoma cell lines, A375 and Bowes, with promising results, confirming increased efficiency of the samples containing both As4S4 and ZnS nanocrystals.

Is It Worthwhile Treating Occluded Cold Stored Venous Allografts by Thrombolysis?

OBJECTIVES: Thrombolysis has been reported to be suboptimal in occluded vein grafts and cryopreserved allografts, and there are no data on the efficacy of thrombolysis in occluded cold stored venous allografts. The aim was to evaluate early outcomes, secondary patency and limb salvage rates of thrombolysed cold stored venous allograft bypasses and to compare the outcomes with thrombolysis of autologous bypasses. METHODS: This was a single center study of consecutive patients with acute and non-acute limb ischemia between September 1, 2000, and January 1, 2014, with occlusion of cold stored venous allografts, and between January 1, 2012, and January 1, 2014, with occlusion of autologous bypass who received intra-arterial thrombolytic therapy. RESULTS: Sixty-one patients with occlusion of an infrainguinal bypass using a cold stored venous allograft (n = 35) or an autologous bypass (n = 26) underwent percutaneous intra-arterial thrombolytic therapy. The median duration of thrombolysis was 20 h (IQR 18-24) with no difference between the groups (p = .14). The median follow up was 18.5 months (IQR 11.0-52.0). Secondary patency rates of thrombolysed bypass at 6 and 12 months were 44 ± 9% and 32 ± 9% in patients with a venous allograft bypass and 46 ± 10% and 22 ± 8% with an autologous bypass, with no difference between groups (p = .40). Limb salvage rates at 1, 6, and 12 months after thrombolysis in the venous allograft group were 83 ± 7%, 72 ± 8% and 63 ± 9%, and in the autologous group 91 ± 6%, 76 ± 9%, and 65 ± 13%, with no difference between groups (p = .69). CONCLUSIONS: Long-term results of thrombolysis of venous allograft bypasses are similar to those of autologous bypasses. Occluded cold stored venous allograft can be successfully re-opened in most cases with a favorable effect on limb salvage.

Positron annihilation lifetime study of polyvinylpyrrolidone for nanoparticle-stabilizing pharmaceuticals.

Positron annihilation lifetime spectroscopy was applied to characterize free-volume structure of polyvinylpyrrolidone used as nonionic stabilizer in the production of many nanocomposite pharmaceuticals. The polymer samples with an average molecular weight of 40,000 g mol(-1) were pelletized in a single-punch tableting machine under an applied pressure of 0.7 GPa. Strong mixing in channels of positron and positronium trapping were revealed in the polyvinylpyrrolidone pellets. The positron lifetime spectra accumulated under normal measuring statistics were analysed in terms of unconstrained three- and four-term decomposition, the latter being also realized under fixed 0.125 ns lifetime proper to para-positronium self-annihilation in a vacuum. It was shown that average positron lifetime extracted from each decomposition was primary defined by long-lived ortho-positronium component. The positron lifetime spectra treated within unconstrained three-term fitting were in obvious preference, giving third positron lifetime dominated by ortho-positronium pick-off annihilation in a polymer matrix. This fitting procedure was most meaningful, when analysing expected positron trapping sites in polyvinylpyrrolidone-stabilized nanocomposite pharmaceuticals.

Adsorption of cadmium(II) on waste biomaterial.

Significant increase of the adsorption ability of the eggshell biomaterial toward cadmium was observed upon milling, as is evidenced by the value of maximum monolayer adsorption capacity of 329mgg(-1), which is markedly higher than in the case of most "green" sorbents. The main driving force of the adsorption was proven to be the presence of aragonite phase as a consequence of phase transformation from calcite occurring during milling. Cadmium is adsorbed in a non-reversible way, as documented by different techniques (desorption tests, XRD and EDX measurements). The optimum pH for cadmium adsorption was 7. The adsorption process was accompanied by the increase of the value of specific surface area. The course of adsorption has been described by Langmuir, Freundlich and Dubinin-Radushkevich isotherms. The adsorption kinetics was evaluated using three models, among which the best correlation coefficients and the best normalized standard deviation values were achieved for the pseudo-second order model and the intraparticle diffusion model, respectively.

Realgar (As4S4) nanoparticles and arsenic trioxide (As2O3) induced autophagy and apoptosis in human melanoma cells in vitro.

The aim of the present study was to compare the effect of realgar nanoparticles and arsenic trioxide (ATO) on viability, DNA damage, proliferation, autophagy and apoptosis in the human melanoma cell lines BOWES and A375. The application of various flow cytometric methods for measurements cell viability, DNA cell cycle, mitochondrial potential, lysosomal activity, and intracellular content of glutathione was used. In addition, quantitative PCR, western blotting and multiplex bead array analyses were applied for evaluation of redox stress, autophagic flux, and cell signaling alterations.The results showed that realgar treatment of studied cells caused modulation of cell proliferation, induced a block in G2/M phase of the cell cycle and altered phosphorylation of IκB, Akt, ERK1/2, p38, and JNK kinases, as well as decreased mitochondrial membrane potential. Additionally, it appeared that induction of cell death by both realgar and ATO was dose-dependent, when lower (0.3 µM) dosage increased lysosomal activity and induced autophagy and higher (1.25 µM) concentration resulted in the appearance of apoptosis, while pan-caspase inhibitor attenuated more efficiently realgar- than ATO-induced cell death. Furthermore, low concentrations of ATO and realgar nanoparticles increased the content of intracellular glutathione and elevated γ-H2AX expression confirmed DNA damage preferentially at higher concentrations of both drugs used. Further analysis revealed slight differences in time-dependent phosphorylation pattern due to both realgar and ATO treatments, while significant differences were noticed between cell lines. In conclusion, realgar nanoparticles and ATO treatment induced dose-dependent activation of autophagy and apoptosis in both melanoma cell lines, when autophagy flux was determined at lower drug concentrations and the switch to apoptosis occurred at higher concentrations of both arsenic forms.

Reinforced aneurysmorrhaphy for true aneurysmal haemodialysis vascular access.

OBJECTIVE: In 2008, a new technique of reinforced aneurysmorrhaphy with a polyester mesh tube for salvaging true aneurysmal arteriovenous (AV) haemodialysis access was described by us. In this study, the long-term patency and complication rates associated with this procedure were analysed, and the effect of reinforced aneurysmorrhaphy on high-flow vascular access was assessed. METHODS: This was a retrospective non-randomised study with prospectively collected data performed at a single centre. Patients with true aneurysmal haemodialysis AV access who underwent aneurysmorrhaphy with external mesh prosthesis between March 2007 and October 2012 were included. Clinical assessment and duplex ultrasound were performed preoperatively, 1, 3, and 12 months postoperatively, and annually thereafter. RESULTS: Data from 62 patients (median age 60 years, range 28-81 years; 63% men) were analysed. The commonest indication was high-flow vascular access associated with the risk of high output cardiac failure (24 patients, 39%). The mean follow-up time was 14.66 ± 12.80 months. Primary patency rates at 6 and 12 months were 86% and 79% respectively. Assisted primary patency rates at 6 and 12 months were 89% and 80% respectively. In 23 patients (96%) operated on for high-flow vascular access, decreased vascular access flow was observed after the procedure. The average flow reduction after aneurysmorrhaphy was 2,197 mL/minute. Postoperative bleeding and infection necessitating surgical revision occurred in three (4.8%) and three (4.8%) patients respectively. CONCLUSIONS: Reinforced aneurysmorrhaphy with an external mesh prosthesis is an effective method for treating true aneurysmal haemodialysis AV access, with excellent long-term patency and minimal complications due to infection.

Arsenic sorption by nanocrystalline magnetite: an example of environmentally promising interface with geosphere.

In this paper, the sorption of arsenic onto nanocrystalline magnetite mineral Fe3O4 was studied in a model system. Nanocrystalline magnetite was produced by mechanical activation in a planetary ball mill from natural microcrystalline magnetite. As a consequence of milling, the specific surface area increased from 0.1m(2)/g to 11.9 m(2)/g and the surface site concentration enhanced from 2.2 sites/nm(2) to 8.4 sites/nm(2). These changes in surface properties of magnetite lead to the enhancement of arsenic removal from model system. The best sorption ability was achieved with magnetite sample activated for 90 min. In this case the sample was able to absorb around 4 mg/g. The structural changes of magnetite were also observed and the new hematite phase was detected after 120 min of milling. A good correlation between the decreasing particle size, increasing specific surface area and reduction of saturation magnetization was found. In desorption study, KOH and NaOH were found as the best eluents where more than 70% of arsenic was released back into the solution. The principal novelty of the paper is that mineral magnetite, truly one nature's gift can be used after "smart" milling (mechanical activation) as an effective arsenic sorbent.

Mesenteric ischemia, new trends, diagnostic methods and algorithms to significantly reduce mortality and morbidity.

This review article summarizes the most recently available data covering the modern trends and methods in the diagnosis and treatment of mesenteric artery disease. Its aim is to point out the critical moments in the whole spectrum of matters such as early diagnosis and treatment of the chronic form of bowel ischemia, role of MDCT in prompt diagnosis, and urgent therapeutic modalities of treating its acute forms. To achieve the best possible results, we must minimize the time of diagnosis while the treatment has to be tailored individually to each patient according to occlusion type, age and co-morbidities (Fig. 2, Ref. 66).

The role of hybrid procedures in the management of peripheral vascular disease.

This paper provides a summary of up-to-date information and experience with the combined treatment of patients suffering from peripheral arterial disease (PAD) with endovascular and open surgery, performed simultaneously and in a single operating room. Hybrid intervention is reported to have good results in well-indicated groups of patients with acute and chronic limb ischemia, even with older, high-risk patients. The indications for the use of this technique remain unclear with inconsistent opinions among vascular surgeons. The indications for treatment were divided into three main groups: 1) Patients with chronic limb ischemia, 2) acute limb ischemia, and 3) occlusion of a previous vascular reconstruction. The operating techniques for the most commonly used combinations are described. In conclusion, hybrid operating techniques are often useful when treating complex problems and multilevel disease in patients with chronic or acute lower limb ischemia. Modern vascular surgeons need to master both open and endovascular techniques, and to combine them in a creative fashion to the benefit of our patients.

[Taxus baccata poisoning]. / Smrtelná otrava tisem cerveným.

Common yew poisoning occurs by per oral application of needles or extracts of needles usually. The determination of the cause of death is more difficult in the latter case. In our article, we advise of circumstances which could be helpful in diagnostic. In addition, we describe the substances contained in yew, their effect, importance and toxicological detection.

[Intraarterial peroperative thrombolysis in therapy of the acute limb ischemia]. / Peroperacní intraarteriální trombolýza v terapii akutní koncetinové ischemie.

Acute limb ischemia is serious situation, jeopardizing limb salvage, causing embolization or thrombosis of the native arteries or vascular graft. Immediate surgical revascularization with balloon thromboembolectomy is indicated in patient with acute ischemia stage IIB of the Rutherford classification. Unfortunately, operative thromboembolectomy is frequently incomplete, with persistent thrombus remaining in the majority of patients. Residual thrombus compromises the clinical outcome, leading to poor revascularization and an increased risk of tissue loss. On depending of amount of the residual thrombus after surgical thromboembolectomy, we can choose one of the three options of intraoperative thrombolysis. This article summarized indication and technical realisation of intraoperative thrombolysis and describe cause report of the first patient treated with this method in our country. The combined use of intraoperative thrombolytics following mechanical thromboembolectomy is safe and efficacious method in patients with acute vascular occlusion.

[3,5-dimethoxyfenol--marker intoxication with Taxus baccata]. / 3,5-dimethoxyfenol-marker intoxikace tisem cerveným.

Autopsy findings of fatal intoxication with yew (Taxus baccata) are nonspecific. A presence of plant residues in the digestive tract can signalize yew intoxication. If yew decoction is consumed, plant residues are not found. In such a case the intoxication can be signalized by the presence of 3,5-dimethoxyphenol in biological material. Authors of this article describe the proof and quantification of the 3,5-dimethoxyphenol in two cases of fatal intoxication with yew. In both cases the liquid/liquid extraction and solid phase extraction was used. Extracts obtained from the acidic and basic environment were analysed. Extracts from the acidic environment were methylated and the extracts from the basic environment were acetylated. The analyses were carried out by gas chromatography/mass spectrometry. In the blood of both intoxicated persons the presence of 3,5-dimethoxyphenol was proved and its concentration 82 ng/ml and 417 ng/ml was quantificated. In both cases the presence of 3,5-dimethoxyphenol was also proved in the gastric contents and urine.

[Clinical experience with cold-preservation of venous and arterial allografts. long-term outcomes]. / Klinické zkusenosti s pouzitím chladem konzervovaných zilních a tepenných allostepu: dlouhodobé výsledky.

INTRODUCTION: Venous and arterial allografts extend the possibilities of peripheral arterial disease as well as vascular prosthesis infections treatment. MATERIAL AND METHODS: Between 10/1997 and 1/2009 we used 112 allogeneic vessels (30 arteries, 82 veins) in 104 patients. Venous allografts were used for 82 reconstructions in 75 patients (M/F 41/34, aged 41-85 years, median 66 years) with critical limb ischemia and no suitable autogenous venous material. Arterial allografts were used in 9 patients (M/F 8/1, aged 56-77 years, median 63 years) with aortoiliac prosthetic infections or mycotic abdominal aortic aneurysms and in 20 transplanted patients (M/F 11/9, aged 32-67 years, median 56 years) with aortoiliac atherosclerotic disease. RESULTS: Patients survival rate after allovenous bypasses was 92% at 1 year and 78% at 3 years. Limb salvage rate was 67% at 1 year and 53% and 3 years. Secondary patency rate was 48% at 1 year and 27% at 3 years. Patient survival rate after alloarterial bypasses was 86% at 1 year and 69% at 3 years. No signs of arterial grafts aneurysmal formation and no need for secondary intervention of any arterial reconstruction was observed during the follow up period in any patient after alloarterial transplantation. CONCLUSIONS: Cold-stored venous and arterial allografts are suitable alternative conduits for limb salvage procedures, vascular prosthesis infections as well as for arterial reconstructions in transplanted patients.

Properties of mechanochemically synthesized ZnS nanoparticles.

The bulk and surface properties of mechanochemically synthesized ZnS nanoparticles were studied. XRD, SEM, TEM (HRTEM), AFM, UV-VIS, low temperature nitrogen sorption as well as TPR characterization methods have been applied. Cubic ZnS nanocrystals (2-4 nm) with characteristic blue shift have been obtained by high-energy milling. There is an evidence of the nanocrystal aggregates formation in products of milling. The surface uniformity, homogeneity as well as enhanced uptake of hydrogen have been documented.

Small bowel graft revascularization in experiment.

OBJECTIVES: The technical aspects of a procedure are most important for the outcome of the experiment. This study was designed to compare two techniques suitable for graft revascularization. METHODS: The first technique, where the animal is both donor and the recipient, consists of connecting the grafts' vascular anastomoses to the mesenteric vessel bed. In the second technique, one animal is the graft donor and the other is the recipient, with revascularization to the central vessel bed (subrenal inferior vena cava and aorta). Techniques of restoring digestive tract continuity and creation of diagnostic "chimney ileostomy" were identical in both groups. All experimental animals were monitored clinically regularly basis as per protocol (weight, temperature, stoma appearance, output and nature of stools). Blood and biopsy samples were obtained on days 0, 3, 5, 7, 10, 20, and 30. RESULTS: Overall, 43 transplant procedures were performed. The first group included 18 transplants and 66.7% animals had vascular complications. While in the second group (25 transplant procedures), vascular complication rate was only 12% (3 out of 25) perhaps due to technique modifications. CONCLUSION: Our experiment showed that both types of vascular anastomosis could be used in small bowel transplantation. Connecting the graft vessels to the aorta and inferior vena cava is technically simpler and safer because of fewer subsequent complications (Tab. 1, Fig. 4, Ref. 6). Full Text (Free, PDF) www.bmj.sk.

[Experimental small intestine transplantation]. / Transplantace tenkého streva v experimentu.

AIM: Transplantation of the small intestine is a standard treatment method in patients with small intestinal failures. The aim of this study was to master the surgical technique, optimalize immunosuppression regimes, diagnose acute cellular graft rejection based on cellular and humoral indicators. METHODS: The authors performed a total of 43 transplantation procedures in pigs. The first, surgical part of the experiment was aimed at mastering two principal methods of vascular anastomosis- firstly, connecting the graft with mesenteric vessels (Group n1 = 18) and secondly, connecting the graft with the aorta and the inferior vena cava (Group n2 = 25). The second part of the experiment included assessment of rejection changes in various immunosuppression regimes. Only animals who did not die because of a technical failure of the procedure or due to internal reasons (n = 24) were assessed. The study animals were assigned to four groups (A (n = 3)--autotransplantation, without immunosuppresion; B (n = 7) and C (n = 8)--allotransplantation with immunosuppression using tacrolimus, resp. in a combination with sirolimus; D (n = 6)--allotransplantation without immunosuppression. Rejection was diagnosed based on histological examination of the grafts@ biopsy samples. Plasmatic citruline was used as a non-invasive humoral indicator of the graft impairment. RESULTS: Procedural complications were observed in 12 (67%) study animals from the first group, and in 3 (12%) animals from the second group. In the assessment of rejection changes, the longest survival was observed with autotransplantations, the shortest survival period was shown with allotransplantations without immunosuppression. No significant survival differences were demonstrated between the both treated groups. (p < 0.05). Group C showed lower rates of cellular rejections, compared to Group B and D. CONCLUSION: During the experiment, the authors managed to master the graft collection, as well as the transplantation technique. Lower rates of surgical complications were observed when the graft was supplied by the central vascular system. No significant differencies were observed between the tacrolimus monoterapy regimen and the combination therapy with sirolimus. Histological examination is the golden standard for the cellular rejection diagnostics. Plasmatic citruline has no signifiance in the rejection assessment.

Aneurysmorrhaphy is an easy technique for arteriovenous fistula salvage.

The life-saving procedures for patients in chronic renal failure (CRF) are hemodialysis (HD) or successful kidney transplantation. HD requires a properly placed and functioning vascular access, most often obtained by creating an arteriovenous fistula (AVF). The long-term patency of AVFs is limited, in addition to other factors, by the development of intimal hyperplasia and the process results in venous wall thickening and progressive fistula occlusion. Another problem is limited patency, due to the development of pseudoaneurysm, which is associated with an increased risk of thrombosis, infection and bleeding, difficult cannulation for dialysis, pain and cosmetic defects. Treatment is focused on rapidly progressing pseudoaneurysms, which can predispose to rupture, technical problems during cannulation because of pseudoaneurysm size or a growing intraluminal thrombus. Most of these patients are scheduled for pseudoaneurysm removal and new fistula construction or, occasionally, an endovascular procedure involving stent graft implantation. This paper describes a simple and inexpensive technique of managing an AVF pseudoaneurysm, i.e. aneurysmorrhaphy. To offset the weakening of the venous wall by suture following aneurysmorrhaphy, an external polyethylene terephthalate (PET) prosthesis was implanted in the vein to prevent the development of intimal hyperplasia in the de novo created AVF.

[Dual kidney transplantation]. / Duální transplantace ledvin.

Despite the increasing demand for organs for transplantation, the number of cadaveric donors remains stable and waiting time for transplantation is gradually getting longer. In addition to the options of using kidneys from living donors and those of non heart-beating donors (NHBD), an alternative approach is transplantation of both kidneys from adult marginal donors who would otherwise be considered unsuitable for single-kidney donation. Dual kidney transplantation involves the use of both kidneys from a marginal donor for a single recipient without the recipient having to cope with the drawbacks of a limited number of functioning nephrons. Normally. these kidneys would be excluded from the transplantation program and remain unused. The submitted presentation provides information on donor and recipient selection criteria and describes the course of the first dual kidney transplantation in an adult recipient in the Czech Republic.