Usage pattern-based exposure screening as a simple tool for the regional priority-setting in environmental risk assessment of veterinary antibiotics: a case study of north-western Germany.

Veterinary antibiotics (VAs) are widely recognized as important environmental contaminants. Despite the extensive use of antibiotic agents in meat and poultry production and the known resistance problems in human and veterinary medicine, detailed knowledge about usage patterns of VAs in Germany is still scarce. This lack of knowledge severely impacts current research on the environmental risk of VAs, but it is expected that recently established surveillance programs for antimicrobial drug usage will close this knowledge gap. Therefore, a spatially more precise environmental risk assessment and management might become possible in the near future. In this study, a new usage pattern-based exposure screening (UPES) approach for the comprehensive environmental exposure assessment of veterinary antibiotics was preliminarily assessed using approximated scenarios of antimicrobial substance usage in German meat and poultry production. Resulting predicted manure concentrations covered seven orders of magnitude ranging from ng kg(-1) to g kg(-1) dry weight (dw). Beyond that 14 antibiotic substances of 10 different antimicrobial classes were predicted to have the potential to occur in soil concentrations higher than 100 µg kg(-1) dw. These findings raise further questions regarding the environmental exposure and risks of frequently used VAs, especially in regions with higher-than-average livestock density. With this case study we demonstrate that UPES simplifies to account for differing local agricultural factors and therefore facilitates priority-setting on a regional level. In this context a simple prioritization scheme for environmental assessment of VAs, considering both the expected environmental concentration and the frequency of application, is proposed in this paper.

Toxicity testing with luminescent bacteria--characterization of an automated method for the combined assessment of acute and chronic effects.

The luminescent bacteria test according to EN ISO 11348 is frequently applied in (eco) toxicity testing and is applicable for a huge variety of environmental and industrial samples. A big disadvantage of this method is the very short exposure time, which is expressed in a low sensitivity in regard to substances with a delayed effect. Chronic effects, i.e. interference with cell growth, cannot be assessed with this conventional standard method. The goal of this research was to develop an automated testing system for long term toxicity towards the luminescent bacteria Vibrio fischeri by implementing microtitration-based instrumentation. The optimized method, hereinafter referred to as "kinetic luminescent bacteria test", can be described as a miniaturized combination of the conventional short-term luminescence inhibition test according to EN ISO 11348 and the Photobacterium phosphoreum growth inhibition test (DIN 38412-37). The validation procedure included the evaluation of six reference compounds (3,4-Dichloroaniline, 3,5-Dichlorophenol, Chloramphenicol, Streptomycin sulfate, Potassium dichromate, Zinc sulfate heptahydrate) and three different endpoints that are acute luminescence inhibition (acute LI) after 30 min, chronic luminescence inhibition (chronic LI) after 24h and growth inhibition (GI) after 14 h. The optimized method allows the assessment of acute and chronic effects within one test, by what a misinterpretation of the toxicity of substances with delayed bacterial toxicity can be prevented, without abandoning most of the advantages of the conventional short-term test. Therefore, the kinetic luminescent bacteria test is exceptional as an initial screening test for environmental samples or substances with unknown (eco) toxicological characteristics.

Chronic ecotoxic effects to Pseudomonas putida and Vibrio fischeri, and cytostatic and genotoxic effects to the hepatoma cell line (HepG2) of ofloxacin photo(cata)lytically treated solutions.

Ofloxacin (OFL), a broad-spectrum and widespread-used photolabile fluoroquinolone, is frequently found in treated wastewaters, aquatic and terrestrial ecosystems leading to increasing concern during the past decades regarding its effects to the environment and human health. The elimination of OFL and other xenobiotics by the application of advanced oxidation processes using photolytic (PL) and photocatalytic (PC) treatments seems promising. However, an integrated assessment scheme is needed, in which, not only the removal of the parent compound, but also the effects of the photo-transformation products (PTPs) are investigated. For this purpose, in the present study, a chronic ecotoxic assessment using representative bacteria of marine and terrestrial ecosystems and a cytostatic and genotoxic evaluation using hepatoma cell line were performed. PL and PC treatments of OFL were applied using UV radiation. The photo-transformation of OFL during the treatments was monitored by DOC measurements and UPLC-MS/MS analysis. The chronic ecotoxicity of OFL and treated samples was evaluated using Pseudomonas putida and Vibrio fischeri; whereas the cytostasis and genotoxicity were estimated by the cytokinesis-block micronucleus assay (CBMN). The main results suggest that photo-transformation of OFL took place during these treatments since the concentration of OFL decreased when the irradiation time increased, as quantified by UPLC-MS/MS analysis, and this was not coupled with an analogous DOC removal. Furthermore, nine compounds were identified as probable PTPs formed through piperazinyl dealkylation and decarboxylation. The ecotoxicity of treated solutions to the bacteria studied decreased while the cytostasis to the hepatoma cell line remained at low levels during both treatments. However, the genotoxicity to the hepatoma cell line demonstrated a different pattern in which treated samples induced a greater number of MNi for the 4-16 min of irradiation (p<0.05) during both treatments. After 64 min of irradiation, the effects decreased to non genotoxic levels (p<0.05). These findings suggest that UV radiation for various treatment processes (catalytic or not), such as disinfection, may create genotoxic by-products. Therefore, in relevant technical applications, the residence time during treatment should receive special attention.

Common non pigmented skin cancer.

The scope of this article does not include many other non melanocytic skin cancers such as angiosarcoma, B cell lymphoma and atypical fibroxanthoma. These are the less common skin cancers, but no less important. If there is any doubt whether a lesion represents a skin cancer, biopsy is mandatory to establish a histopathological diagnosis so that treatment can ensue.

A clinical and histopathologic study of granulomatous rosacea.

A retrospective clinical and histopathologic study of 53 patients with granulomatous rosacea was undertaken. The patients had a broad clinical spectrum of lesions that ranged from primarily erythema to papulonodular lesions. Extrafacial lesions occurred in 15% of patients. Histologic examination showed mixed lymphohistiocytic inflammation (primarily lymphocytic inflammation in 40% of patients and primarily histiocytic with a few giant cells in 34%), epithelioid granulomas in 11% of patients, and epithelioid granulomas with caseation necrosis in 11%. Most patients had a good response to oral antibiotic therapy. Granulomatous rosacea is not a distinct disease but can be regarded and treated as a subtype of rosacea.

Entropy balances of microbial product formation.

Considering the approach of Bermudez and Wagensberg (1986) devoted to the entropy balance of growing microorganisms some equations were developed which describe particularly the entropy balance of microbial product formation. The formula allows to determine the coefficients of resistance R(mn) and of coupling L(mn) according to rates of growth, product formation, maintenance metabolism and heat evolution assuming a linear relationship between thermodynamic fluxes and forces. In order to check the usefulness of the derived model appropriate experimental data of two microbial batch processes concerning production of L-lysine and the antibiotic nourseothricine were taken into account. The results showed similar courses of entropy balances despite different pathways of product formation which were characterized by an overshoot of entropy production at the beginning of biosynthesis of the primary and secondary metabolite. This fact was interpreted as a more general phenomenon for microorganisms under inbalanced nutritional conditions.

Photopatch testing: a six-year experience.

The results of photopatch testing performed at the Mayo Clinic from 1980 through 1985 were analyzed. During the 6 years, 70 patients underwent photopatch testing. Of the 70 patients, 27 (38.5%) had positive photopatch test reactions and 22 (31%) had ordinary contact reactions. Of the 27 patients with photocontact reactions, 14 had relevant reactions. The most frequent positive reactions were to chlorpromazine (13 patients), musk ambrette (nine patients), and promethazine (eight patients). Photopatch testing is an essential part of the evaluation of patients who are suspected of having photosensitive dermatitis. In some patients with recalcitrant eruptions, testing may help in excluding photosensitivity as a possible contributing factor.

Sensitivity to wild vegetation.

74 patients suspected of having allergic contact dermatitis to wild vegetation were patch tested with either extracts of 13 plants of the family Compositae and 7 other weeds or trees. Anthemis cotula (dog fennel) and Xanthium strumarium (cocklebur) gave the most frequent positive results, demonstrating a change of frequency in sensitivity compared to the 1950s, when Ambrosia artemisiifolia (ragweed) was recognized as the most frequently sensitizing weed. The reasons for these changes of incidence and clinical patterns are examined.

Contact dermatitis from Grevillea 'Robyn Gordon'.

Grevillea 'Robyn Gordon' is an Australian hybrid plant which may cause allergic contact dermatitis. Over the past 8 years, it has been planted extensively in Australia and is now being exported to the United States and other Western countries. Recently, an explosion in incidence of contact dermatitis due to this plant has been seen. 24 patients who were suspected of being sensitive to it were patch tested to fresh plant and extracts with confirmation of sensitivity. A cross sensitivity to Toxicodendron was demonstrated clinically and on patch testing. The allergen in Toxicodendron, 3 pentadecylcatechol, is closely linked in chemical structure to 5-pentadecylresorcinol, present in Grevillea banksii and tridecylresorcinol in Grevillea robusta. Patch testing in patients sensitive to Grevillea 'Robyn Gordon' with tridecylresorcinol produced positive reactions, thus implicating the sensitizing rôle of long chain alkyl resorcinols in Grevillea 'Robyn Gordon' allergy. There is a likelihood that this sensitizing potential extends to other plants of the Grevillea genus, e.g., Grevillea robusta. With the spread of Grevillea 'Robyn Gordon' to other markets, this problem will become increasingly common.

The dysplastic naevus syndrome in patients with cutaneous malignant melanoma in Western Australia.

One hundred and three patients with cutaneous malignant melanoma responded to an invitation to attend a dermatology outpatient clinic. All patients with a family history of melanoma, a history of multiple melanomas, or histological evidence of a dysplastic naevus that was associated with their melanoma were invited. A random sample of other patients with cutaneous malignant melanoma was also invited to attend. First-degree relatives of patients with the dysplastic naevus syndrome (DNS) were invited for a similar examination. DNS was found in 27% of the patients with a family history of melanoma, multiple melanomas, or histological evidence of a dysplastic naevus in association with their melanoma, and in 6% of the remaining patients who were selected at random. DNS was estimated to be present in 12.8% of 17- to 55-year-old patients with cutaneous malignant melanoma in the Perth region, while familial DNS was present in 4.5%. Patients with melanomas with DNS were more likely to be young men and to have numerous naevi, particularly on the lateral surfaces of the arms, shoulders and trunk, than were patients with melanomas without the syndrome.