Monitoring, removal and risk assessment of cytostatic drugs in hospital wastewater.

Cytostatic agents are applied in cancer therapy and subsequently excreted into hospital wastewater. As these substances are known to be carcinogenic, mutagenic and toxic for reproduction, they should be removed from wastewater at their source of origin.In this study the fate and effects of the cancerostatic platinum compounds (CPC) cisplatin, carboplatin, oxaliplatin, 5-fluorouracil (5-FU) and the anthracyclines doxorubicin, daunorubicin and epirubicin were investigated in hospital wastewater. Wastewater from the in-patient treatment ward of a hospital in Vienna was collected and monitored for the occurrence of the selected drugs. A calculation model was established to spot the correlation between administered dosage and measured concentrations. To investigate the fate of the selected substances during wastewater treatment, the oncologic wastewater was treated in a pilot membrane bioreactor system (MBR) and in downstream advanced wastewater treatment processes (adsorption to activated carbon and UV-treatment). Genotoxic effects of the oncologic wastewater were assessed before and after wastewater treatment followed by a risk assessment.Monitoring concentrations of the selected cytostatics in the oncologic wastewater were in line with calculated concentrations. Due to different mechanisms (adsorption, biodegradation) in the MBR-system 5 - FU and the anthracyclines were removed < LOD, whereas CPC were removed by 60%. In parallel, genotoxic effects could be reduced significantly by the MBR-system. The risk for humans, the aquatic and terrestrial environment by hospital wastewater containing cytostatic drugs was classified as small in a preliminary risk assessment.     

Fission gas induced swelling in uranium at high temperatures and pressures

The effect of externally applied hydrostatic pressures from 0–1000 bar at 900 °C on the fission gas induced swelling in uranium has been studied. The swelling is a sensitive function of pressures below 110 bar and relatively insensitive to pressures above 110 bar. Metallography of the samples show that the average diameter of the bubbles is reduced from 3300 to 1800 Å and the total number increased from 0.9 to 4.2 × 10¹²/cm³ as the annealing pressure is increased from 0–110 bar respectively. Further increases in pressure from 110–1000 bar have little effect on the average bubble size and density. The mechanism of pressure reduced swelling is discussed in terms of the equilibrium number of vacancies that can be associated with fission gas atoms under stress. It is also shown, both experimentally and theoretically, that there is a loss of surface area when bubbles coalesce under pressure.     

Patterns in the crustacean zooplankton community in Lake Winnipeg,Manitoba: Response to long-term environmental change

Changes in the crustacean zooplankton community composition and abundance in Lake Winnipeg (1969–2006) provide a rare opportunity to examine their response to environmental changes in the largest naturally eutrophic lake on the Canadian prairies. Since 1929, zooplankton species composition in Lake Winnipeg has changed little except for the addition of the invasive cladoceran, Eubosmina coregoni in 1994. The dominant taxa in the lake in summer include: Leptodiaptomus ashlandi, Acanthocyclops vernalis, Diacyclops thomasi, Daphnia retrocurva, Daphnia mendotae, Diaphanosoma birgei, Eubosmina coregoni, and Bosmina longirostris. Climate-accelerated nutrient loading to southern Lake Winnipeg over the last two decades has led to increased phytoplankton abundance and higher frequency of cyanobacterial blooms especially in its northern basin. Crustacean zooplankton have likewise increased especially in the North Basin, but less so in the more nutrient rich South Basin, possibly as a consequence of higher densities of pelagic planktivorous fish and light-limited primary production compared with the more transparent North basin (Brunskill et al., 1979, 1980). Calanoid copepods play a larger role in the South basin food web in contrast to cyclopoid copepods and Cladocera in the North basin. The study begins to fill the recognized gap in understanding of Lake Winnipeg's food web structure and provides a baseline for evaluating ongoing changes in the zooplankton community with the arrival of new non-indigenous taxa, e.g. Bythotrephes longimanus and Dreissena polymorpha. It reinforces previous work demonstrating that zooplankton provide valuable indices toward evaluating the health of an ecosystem.     

Inexpensive synthesis of 1,4-bis(4-aminophenoxy)-2- (6-oxido-6H-dibenz <c,e> <1,2> oxaphosphorin-6-yl) phenylene and its oxygen-plasma resistant polyamides

Inexpensive synthesis of diamine, 1,4-bis(4-nitrophenoxy)-2-(6-oxido-6H-dibenz <c,e> <1,2> oxaphosphorin-6-yl) phenylene was revealed in this work. Based on the diamine, a series of organosoluble polyamides were prepared by direct polycondensation of the diamine with various aromatic diacids using triphenyl phosphite and pyridine as condensing agents. The number-average molecular weights of the resulting polyamides range from 4.2 × 10⁴ to 10.5 × 10⁴ g/mol, and the weight-average molecular weights are in the range of 7.5-28.2 × 10⁴ g/mol. The T_gs of these polyamides range from 210 to 255 °C by dynamic mechanical analysis. The resulting polyamides are tough and flexible with tensile strength, elongation at break and moduli range from 84 to 101 MPa, 4.8-7.0%, and 2.36-3.22 GPa, respectively. The degradation temperatures (T_d 5%) and char yields at 800 °C in nitrogen range from 460 to 486 °C and 59-68 wt%, respectively. The cutoff wavelength of these polyamides falls in the range of 345-366 nm, showing a very light color characteristic. In addition, these polyamides display good oxygen plasma resistance.     

Integral-based parameter identification for long-term dynamic verification of a glucose-insulin system model

Hyperglycaemia in critically ill patients increases the risk of further complications and mortality. This paper introduces a model capable of capturing the essential glucose and insulin kinetics in patients from retrospective data gathered in an intensive care unit (ICU). The model uses two time-varying patient specific parameters for glucose effectiveness and insulin sensitivity. The model is mathematically reformulated in terms of integrals to enable a novel method for identification of patient specific parameters. The method was tested on long-term blood glucose recordings from 17 ICU patients, producing 4% average error, which is within the sensor error. One-hour forward predictions of blood glucose data proved acceptable with an error of 2-11%. All identified parameter values were within reported physiological ranges. The parameter identification method is more accurate and significantly faster computationally than commonly used non-linear, non-convex methods. These results verify the model's ability to capture long-term observed glucose-insulin dynamics in hyperglycemic ICU patients, as well as the fitting method developed. Applications of the model and parameter identification method for automated control of blood glucose and medical decision support are discussed.     

Computer-assisted feedback-driven quality management for psychotherapy: The Stuttgart-Heidelberg Model.

The authors present the Stuttgart-Heidelberg Model for quality management of psychotherapy. The system is characterized as an active internal approach with external support from researchers. Problem solving activities are initiated and maintained by computer-assisted feedback on possible treatment shortcomings. The system provides support for the 3 key tasks of quality management; (a) monitoring of relevant quality criteria in the clinical routine, (b) standardized assessment that allows comparison with established standards at various levels of service provision, and (c) transfer of information on achieved quality to those whom it concerns. The central function of the system is an alarm function, signaling a possible deficit of the provided psychotherapy on the basis of the standard evaluation of treatment outcome for individual patients. In this article, the main system components are described and data on its feasibility and validity are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An investigation into the antimicrobial mechanisms of action of two contact lens biocides using electron microscopy.

Polyquaternium-1 (PQ-1) and myristamidopropyl dimethylamine (MAPD) are biocides used commercially in a contact lens disinfecting solutions. Electron microscopy was used to provide further evidence on the mechanism(s) of action of these agents against a wide range of ocular pathogens including bacteria, fungi and protozoa. Both PQ-1 and MAPD caused multiple forms of damage to the organisms tested, evidenced by structural alterations, blebbing, leakage and cell destruction. The extent of damage and the selectivity against specific type of microorganisms was consistent with the antimicrobial activity of these agents. Although electron microscopy is a powerful tool, it has its limitations when used to examine the mode of action of biocides. Indeed, there was no evidence of gross structural alteration to Acanthamoeba castellani or Aspergillus fumigatus following treatment.     

Demyelination and single-carbon transfer pathway metabolites during the treatment of acute lymphoblastic leukemia: CSF studies

PURPOSE: To investigate the hypothesis that methotrexate causes demyelination due to a deficiency in S-adenosylmethionine (SAM) during the treatment of acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: Twenty-four patients treated on the Medical Research Council United Kingdom ALL trial no. 11 (MRC UKALL XI) were studied. The trial randomized patients at the presymptomatic CNS treatment (PCNS) phase to receive (1) intrathecal methotrexate and cranial radiotherapy (CRTX); (2) high-dose intravenous methotrexate with folinic acid rescue and continuing intrathecal methotrexate (HDMTX); and (3) continuing intrathecal methotrexate alone (ITMTX). Serial CSF samples were collected throughout treatment and concentrations of 5-methyltetrahydrofolate (MTF), methionine (MET), SAM, and myelin basic protein (MBP) were measured. The results were grouped into treatment milestones and compared with an age-matched reference population. RESULTS: There was a highly significant effect of both treatment milestones and trial arm on the metabolite and MBP concentrations. CSF MTF reached a nadir during the induction phase of treatment, while SAM and MET reached their nadir during the consolidation phase. CSF MBP mirrored SAM concentration and there was a significant inverse relationship between the two. MTF, SAM, and MBP returned to normal values by the end of treatment, while MET was increased significantly. The effect of treatment was decremental across the ITMTX, HDMTX, and CRTX groups. CONCLUSION: Treatment of ALL causes marked abnormalities in the single-carbon transfer pathway and subclinical demyelination. Methotrexate is one cause of this. Whether these abnormalities contribute to the late cognitive deficits requires further study.     

An in vitro approach for the study of dentinogenesis by organ culture of the dentine-pulp complex from rat incisor teeth

This article focuses on the experiences and role of a tutor while conducting a problem based learning (PBL) exercise to facilitate the learning of biochemistry and molecular biology. A case presentation of sickle cell anemia was used to frame a module. The objective of this experimental exercise was to assess the suitability and effectiveness of problem based learning in the first year of undergraduate medical course and to practice self-assessment by tutors in this new role of a facilitator of learning through small group discussion. A tutor during such a learning session encouraged the students to apply their reasoning to analyze the problem and to develop self-directed learning skills in acquiring the knowledge appropriate to their perceived needs to work on a problem. The tutors ensured that they apply this knowledge in their work with other similar problems that they would encounter later in life.