Qualitative and Quantitative Analysis of Certain Aspects of the Cytotoxic and Genotoxic Hazard of Hospital Wastewaters by Using a Range of In Vitro Assays.

Health care facilities and hospitals generate significant amounts of wastewater which are released into the sewage system, either after a preliminary treatment or without any further treatment. Hospital wastewater may contain large amounts of hazardous chemicals and pharmaceuticals, some of which cannot be eliminated entirely by wastewater treatment plants. Moreover, hospital effluents may be loaded with a plethora of pathogenic microorganisms or other microbiota and microbiome residues. The need to monitor hospital effluents for their genotoxic hazard is of high importance, as detailed information is scarce. DNA-based information can be acquired directly from samples through the application of various molecular methods, while cell-based biomonitoring assays can provide important information about impaired cellular pathways or mechanisms of toxicity without prior knowledge of the identity of each toxicant. In our study, we evaluated samples of chlorinated hospital wastewater discharged into the sewage system after this disinfection process. The assessment of cytotoxicity, genotoxicity and mutagenicity of the hospital effluents was performed in vitro by using a broad battery of biomonitoring assays that are relevant for human health effects. All the tested hospital wastewater samples could be classified as potentially genotoxic, and it is concluded that the microbiota present in hospital wastewater might contribute to this genotoxic potential.

Genotoxicity of wastewater from health care facilities.

Health care facilities use for therapeutic purposes, diagnostics, research, and disinfection a high number of chemical compounds, such as pharmaceuticals (e.g. antibiotics, cytostatics, antidepressants), disinfectants, surfactants, metals, radioactive elements, bleach preparations, etc. Hospitals consume significant amounts of water (in the range of 400 to 1200 liters/day/bed) corresponding to the amount of wastewater discharge. Some of these chemicals are not eliminated in wastewater treatment plants and are the source of pollution for surface and groundwater supplies. Hospital wastewater represents chemical and biological risks for public and environmental health as many of these compounds might be genotoxic and are suspected to contribute to the increased incidence of cancer observed during the last decades. The changes of the genetic information can have a lethal effect, but more often cause tumor processes or mutations in embryonic development causing serious defects. A review of the available literature on the mutagenicity/genotoxicity of medical facilities wastewater is presented in this article.

Eye irritation hazard of chemicals and formulations assessed by methods in vitro.

BACKGROUND: The aim of this study was to compare human and animal skin irritation data with results of selected in vitro methods, including HET-CAM test, Neutral Red Release Assay, Neutral Red Uptake Assay and EpiOcular eye irritation test and with already existing data of eye irritation obtained from animal experiments. METHODS: Chemicals employed in previous skin irritation validation studies and commercially available cosmetic formulations were subjected to further testing using in vitro methods Neutral Red Release (NRR) assay, Neutral Red Uptake (NRU) assay, HET-CAM test and EpiOcular assay. RESULTS: The study revealed that skin irritants are not necessarily eye irritants; specifically volatile or solid materials may be misclassified. NRR assay provided false negative results in case of substances with fixative effect or not removable under standard washing procedure, emphasizing the role of microscopical evaluation as a crucial additional endpoint. Although overpredictive, HET-CAM test provided the lowest false negative rate. The most aggressive cosmetic formulation was correctly identified by EpiOcular assay, in accordance with NRU and NRR assays results, while HET-CAM test correctly identified the mildest formulation. CONCLUSIONS: Each of the in vitro methods is related to a specific endpoint of ocular irritation and provides only partial information on the mode of action of the tested material. Despite good reproducibility of individual in vitro assays, only the weight-of-evidence approach and results of multiple selected in vitro tests can allow for estimation of eye irritation hazard in vivo.

Toxicity hazard of organophosphate insecticide malathion identified by in vitro methods.

OBJECTIVES: Malathion is generally not classified as toxic. However, the toxicity seems to be species-dependent. Local and systemic toxicity data for birds are rare, but a decrease of wild bird densities in areas where malathion was applied was reported. Aim of the study was to extend knowledge on malathion toxicity on cellular and organ level and to evaluate embryotoxicity and genotoxicity for birds using the chick embryo model HET-CAM. METHODS: Skin and eye irritation was determined using reconstructed skin and eye cornea tissues and the chorioallantoic membrane of chick embryo to simulate conjunctiva. Cytotoxicity in 3T3 Balb/c fibroblast culture was determined to estimate acute systemic toxicity. Chick embryo model was further employed to evaluate acute embryotoxicity for birds (mortality and genotoxicity). Data were analysed by means of general linear models. RESULTS: Malathion is not a skin and eye irritant. Cytotoxicity in vitro test provided LD50 value of 616 mg/kg suggesting higher toxic potential than is generally published based on in vivo tests on laboratory rodents. Embryotoxicity studies revealed dose and age dependent mortality of chick embryos. Genotoxicity was identified by means of micronucleus test in erythroid cells isolated from chorioallantois vascular system of chick embryos. CONCLUSIONS: Using in vitro alternative toxicological methods, a higher toxic potential of malathion was demonstrated than is generally declared. An increased health and environmental hazard may occur in areas with intensive agricultural production. The environmental consequences of delayed effects and embryotoxicity for bird populations in areas exposed to organophosphate insecticides, such as malathion, are obvious.

Individual differences in the effectiveness of intracoronary bone marrow cell transplantation assessed by gated sestamibi SPECT/FDG PET imaging.

BACKGROUND: The impact of different levels of tracer uptake on improvements of left-ventricular (LV) function was analyzed in patients treated by intracoronary bone marrow cell (BMC) transplantation. METHODS AND RESULTS: Thirty-one patients with irreversible damage after their first acute myocardial infarction (MI), as confirmed by sestamibi single-photon emission computed tomography (MIBI SPECT)/fluorodeoxyglucose positron emission tomography (FDG PET), underwent high-dose (1 x 10(8) cells) BMC transplantation, whereas 31 similar patients were randomly integrated into a control group. In 11 BMC-treated patients with very low sestamibi uptake at less than 30% of maximum in the infarcted area, the mean left-ventricular ejection fraction (LVEF) improved after 3 months of follow-up by 3% only, and mean end-diastolic/end-systolic volumes (EDV/ESV) enlarged by 10/1 mL (P = NS vs controls). In 20 BMC-treated patients with higher sestamibi uptake in the range of 31% to 50% of maximum, LVEF improved by 7%, and EDV/ESV decreased by 5/12 mL (P < .05 vs BMC-treated subgroup with low MIBI uptake and controls). No similar categorization was seen in the control group: in patients with higher sestamibi uptake or very low uptake, the LVEF increased by 2% and 3% only, and the EDV/ESV enlarged in both subgroups by 12/4 mL and 12/2 mL, respectively (P = NS). CONCLUSIONS: Our results suggest the capability of SPECT/PET imaging to select patients who will receive the maximum benefit from BMC therapy.

Cell therapy in patients with left ventricular dysfunction due to myocardial infarction.

OBJECTIVES: The purpose of this study was to determine the impact of autologous transplantation of mononuclear bone marrow cells on myocardial function in patients with left ventricular (LV) dysfunction due to an acute myocardial infarction. METHODS: The randomized study included 82 patients with a first acute myocardial infarction treated with a stent implantation. This presentation is a subanalysis of 47 patients with left ventricular dysfunction-EF (ejection fraction)

Autologous transplantation of mononuclear bone marrow cells in patients with acute myocardial infarction: the effect of the dose of transplanted cells on myocardial function.

BACKGROUND: Despite the reports on successful treatment of acute myocardial infarction using autologous mononuclear bone marrow cell transplantation, many unresolved questions still remain. We studied the impact of the dose of transplanted cells on myocardial function and perfusion. METHODS: Sixty-six patients with a first acute myocardial infarction were randomized into 3 groups. Two groups were intracoronarily given mononuclear bone marrow cells in either higher (10(8) cells, higher cell dose [HD] group, n = 22) or lower (10(7) cells, lower cell dose [LD] group, n = 22) doses. Twenty-two patients without cell transplantation served as a control (C) group. RESULTS: At 3 months of follow-up, the baseline peak systolic velocities of longitudinal contraction of the infarcted wall of 5.2, 4.5, and 4.3 cm/s in C, LD, and HD groups increased by 0.0, 0.5 (P < .05 vs C group), and 0.9 cm/s (P < .05 vs LD group, P < .01 vs C group), respectively, as demonstrated by Doppler tissue imaging. Baseline left ventricular ejection fractions of 42%, 42%, and 41% in C, LD, and HD groups increased by 2%, 3%, and by 5% (P < .05 vs group C), respectively, as assessed by the gated technetium Tc 99m sestamibi single photon emission computed tomography. CONCLUSIONS: Mononuclear bone marrow cell transplantation improves regional myocardial function of the infarcted wall in a dose-dependent manner.

The role of quantitative Tc-99m-MIBI gated SPECT/F-18-FDG PET imaging in the monitoring of intracoronary bone marrow cell transplantation.

BACKGROUND: A lot of unresolved questions still exist concerning the exact mechanism of the beneficial effects of bone marrow cell (BMC) transplantation for myocardial regeneration. The aim of this communication is to report the cases of patients with and without post-transplantation left ventricular function improvement. MATERIAL AND METHODS: To this study we included consecutive patients with irreversible damage after a first acute ST-elevation myocardial infarction treated by coronary angioplasty with stent implantation. The irreversible damage was identified by dobutamine echocardiography and confirmed by rest gated Tc-99m-MIBI gated SPECT and in the majority of patients by F-18-FDG PET imaging as well. Using 4D-MSPECT software, we quantified MIBI/FDG uptake and gated SPECT left ventricular ejection fraction, end-diastolic/end-systolic volumes (LVEF, EDV/ESV) before BMC therapy and 3 months later. RESULTS: The results obtained in the initial group of patients in this study (27 patients in the BMC treated group, 16 patients in the control group) have been published previously [Eur J Nucl Med 2005; 32 (Suppl 1 ): S46]. Among the BMC group, we identified 13 responders to therapy with average LVEF improvement from 43.3% +/- 11% to 51.4% +/- 10.4% and EDV/ESV improvement from 145 ml/84 ml to 133 ml/67 ml. The remaining 14 patients were non-responders to therapy with no significant change in LVEF (39.1% +/- 8.1% versus 39.8% +/- 7.4%), the EDV/ESV increased from 166 ml/105 ml to 188 ml/116 ml. Responders to the cell therapy had prevailing MIBI uptake in the range of 31-50% of maximum in the infarction territory. On the other hand, non-responders to BMC therapy had prevailing MIBI uptake in the range of 0-30% of maximum. Two cases are presented in this report. CONCLUSIONS: Further studies with a larger cohort of patients would be helpful to evaluate our findings. We observed strong interindividual differences in the effectiveness of the cell therapy. Prevailing residual MIBI uptake in the range of 31-50% of maximum was in the subgroup of responders to the cell therapy.

[Our experience with prevention of infection in patients post splenectomy.].

Splenectomy significantly impairs the immunity of the body; in a certain proportion of the patients this may cause the so-called OPSI (overwhelming post-splenectomy infection) syndrome, i. e. incidence of fulminant life-threatening infections. Even today, despite highly efficacious sophisticated antibiotics, this condition is burdened with very high mortality. In our paper we describe the management and preventive measures in splenectomized subjects at the Department of Infectious Diseases of the Teaching Hospital Brno.

Three-, 6-, and 12-month results of autologous transplantation of mononuclear bone marrow cells in patients with acute myocardial infarction.

BACKGROUND: There are only few data on long-term effectiveness of the stem cell therapy. AIM: We studied the time course of global and regional left ventricular function in patients with acute myocardial infarction within 1 year after the autologous mononuclear bone marrow cell transplantation. METHODS: Sixty patients with a first acute myocardial infarction, who had been randomized into 3 groups, completed a 12-month protocol. Two groups were intracoronarily given bone marrow cells in either higher (10(8) cells, HD group, n=20) or lower (10(7) cells, LD group, n=20) doses. Twenty patients without cell transplantation served as a control (C) group. Doppler tissue imaging and the gated technetium-99m sestamibi single photon emission computed tomography were performed before cell transplantation and at 3, 6, and 12 months later. RESULTS: The baseline peak systolic velocities of longitudinal contraction of the infarcted wall (S(infarct)) of 5.2 cm/s, 4.6 cm/s, and 4.4 cm/s in C, LD, and HD groups increased by 0.0 cm/s, 0.3 cm/s (p=NS vs. C group), and by 0.7 cm/s (p<0.05 vs. C group), respectively, at 3 months. At 12 months, however, the corresponding changes from baseline values of 0.1 cm/s, 0.2 cm/s, and 0.6 cm/s did not differ significantly (all p=NS). In contrast, the post-transplant improvements in the left ventricular ejection fraction by 6%, 7%, and 7% at months 3, 6, and 12, respectively, were preserved in HD group patients during the whole 12-month follow-up and remained significantly better as compared to controls. CONCLUSIONS: In our study, the autologous mononuclear bone marrow cell transplantation provided sustained improvement in global left ventricular systolic function in patients with acute myocardial infarction. However, when evaluating regional systolic function of the infarcted wall, the short-term benefit was partially lost during the 12-month follow-up.