Harlan Laboratories Ltd.

Itingen, Switzerland

Harlan Laboratories Ltd.

Itingen, Switzerland

Time filter

Source Type

Wehrhan A.,Jülich Research Center | Wehrhan A.,Harlan Laboratories Ltd. | Streck T.,University of Hohenheim | Groeneweg J.,Jülich Research Center | And 2 more authors.
Journal of Environmental Quality | Year: 2010

Antibiotics, such as sulfadiazine (SDZ), may enter arable soil by spreading of manure of medicated husbandry or directly by the excrement of grazing animals. Knowledge of the fate of antibiotics in soils is crucial for assessing the environmental risk of these compounds, including possible transport to ground water. Kinetic sorption of 14C-labeled SDZ (4-amino-N-pyrimidin-2-yl- benzenesulfonamide) was investigated using the batch technique. The batch sorption-desorption experiments were conducted at various concentration levels (0.044-13 mg L-1 initial solute concentration) and time scales (0.75-272 d). Sorption of 14C-SDZ in the investigated silty loam was time dependent and strongly nonlinear in the solution phase concentration. The time to reach an apparent sorption equilibrium was about 20 d. However, desorption was very slow, and 41 d were insuficient to reach the desorption equilibrium. An inverse modeling technique was used to identify relevant sorption processes of 14C-SDZ during the batch experiments. Among the investigated two- and three-domain sorption models, adsorption and desorption of 14C-SDZ were best described with a new model defining two sorption domains and four parameters. Whereas sorption in the first sorption domain was nonlinear and instantaneous, solute uptake in the second sorption domain was rate limited following first-order kinetics. Desorption followed the same rate law until an equilibrium distribution was reached. After that, desorption was assumed to be impossible due to partly irreversible sorption. Although the proposed model needs further validation, it contributes to the discussion on complex sorption processes of organic chemicals in soils. Copyright © 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.


Zimmer D.,Harlan Laboratories Ltd. | Zimmer D.,Hoffmann-La Roche | Hassler S.,Harlan Laboratories Ltd. | Betschart B.,Harlan Laboratories Ltd. | And 3 more authors.
Bioanalysis | Year: 2013

Background: The scientifically and logistically best way of application of the internal standard (IS) in the analysis of dried blood spots (DBS) analysis is still a matter of debate and investigation. Most commonly the IS is added in the solvent used for extraction of the discs punched from DBS. In this case, the recovery of the non-extracted IS is complete while the recovery of the analyte extracted from DBS is different from the IS. Results: An alternative way for addition of the IS was investigated. A homogeneous distribution and absorption of the test compound across the spots was demonstrated by spraying a solution of a radiolabeled test compound (mimicking an IS solution) onto DBS. Conclusion: This spray-on technique is convenient and easily automatable. Spraying of the solution was rapid, precise and reproducible, and therefore seems to be suitable for routine analysis of DBS by offline and online extraction. © 2013 Future Science Ltd.


Lorenz C.,ETH Zurich | Von Goetz N.,ETH Zurich | Scheringer M.,ETH Zurich | Wormuth M.,Harlan Laboratories Ltd | Hungerbuhler K.,ETH Zurich
Nanotoxicology | Year: 2011

The rapid increase in the number of consumer products containing engineered nanoparticles (ENP) raises concerns about an appropriate risk assessment of these products. Along with toxicological data, exposure estimates are essential for assessing risk. Currently, cosmetics and personal care products (C&PCP) represent the largest ENP-containing consumer product class on the market. We analyzed factors influencing the likelihood that ENP-containing products are available to consumers. We modelled potential external exposure of German consumers, assuming a maximum possible case where only ENP-containing products are used. The distribution of exposure levels within the population due to different behavior patterns was included by using data from an extensive database on consumer behavior. Exposure levels were found to vary significantly between products and between consumers showing different behavior patterns. The assessment scheme developed here represents a basis for refined exposure modelling as soon as more specific information about ENPs in C&PCP becomes available. © 2011 Informa UK, Ltd.


Von Goetz N.,ETH Zurich | Wormuth M.,Harlan Laboratories Ltd. | Scheringer M.,ETH Zurich | Hungerbuhler K.,ETH Zurich
Risk Analysis | Year: 2010

Bisphenol A (BPA) is an endocrine disrupting chemical that is found in human urine throughout industrial societies around the globe. Consumer exposure pathways to BPA include packaged food, household dust, air, and dental fillings. To date, information on the relative contribution of the different pathways to total consumer exposure is lacking, but is key for managing substance-associated risks. We investigated the relative contributions of the pathways known to be most relevant for nine different consumer groups. Our results suggest that the most important pathways for infants and children are the use of polycarbonate (PC) baby bottles and for adults and teenagers the consumption of canned food. Dental surgery can also considerably contribute over a short time directly after the surgery. For infants fed with PC baby bottles with mean dose rates of 0.8 μg/kgbw/d the highest exposure dose rate was calculated. This dose rate is far below the tolerable daily intake of 50 μg/kgbw/d. However, it is of the same order of magnitude as recently reported concentrations that caused low-dose health effects in rodents. We find a pattern of falling exposure levels with rising age that is supported by urinary concentrations of BPA available for selected consumer groups. Similarly, the exposure levels we predict are confirmed by the levels reported in these studies. © 2010 Society for Risk Analysis.


Thorpe K.L.,University of Basel | Thorpe K.L.,University of Prince Edward Island | Marca Pereira M.L.,University of Basel | Schiffer H.,University of Basel | And 3 more authors.
Aquatic Toxicology | Year: 2011

Exogenous treatment of fish with natural sex hormones and their mimics has been shown to influence gonadal differentiation resulting in biased phenotypic sex-ratios. This has lead to the development of the Fish Sexual Development Test (FSDT) as a method for the detection of endocrine active chemicals. Proposed test organisms include the medaka, zebrafish (ZF) and stickleback, although the guideline also allows for inclusion of species such as the fathead minnow (FHM), provided the test duration allows for sufficient sexual differentiation. However, although the processes underlying sexual differentiation are known to differ for each of these species, it is not known how, or if, these differences would influence the results of the FSDT. In the experiments reported here, responses of the ZF and FHM to prochloraz, a sterol biosynthesis inhibitor and androgen antagonist, were characterized and compared. Exposure to 320. μg/L of prochloraz, from embryo until 60 (ZF) or 95-125 (FHM) days post hatch inhibited somatic growth of both species, but while a negative impact on ZF larval survival was observed (LOEC 32. μg/L) there was no evidence for an effect on FHM larval survival. Prochloraz influenced sexual differentiation in both species by decreasing the proportion of females (LOEC 100. μg/L (ZF), 320. μg/L (FHM)) and delaying completion of sexual differentiation; manifest as an increased incidence of ovotestis in the ZF (LOEC 100. μg/L) and as an increased number of fish with undifferentiated gonads in the FHM (LOEC 320. μg/L). However, while exposure to 320. μg/L prochloraz delayed maturation of the differentiated FHM testis, there was no such effect in the ZF. These results demonstrate that the different strategy of sexual differentiation in the ZF and FHM influences the profile of responses of their gonads to the masculinising effects of prochloraz, but does not affect their overall sensitivity. © 2011 Elsevier B.V.


Human health and environmental hazards of chemical substances must be assessed in relation to estimated or measured exposure levels, reported to ECHA and communicated within the supply chain by registrants under the REACH regulation framework. This article gives an overview of the requirements and practical guidance on how to perform the Chemical Safety Assessment (CSA) and appropriately document the outcomes of the assessment in the Chemical Safety Report (CSR).


Weber K.,Harlan Laboratories Ltd.
Toxicologic pathology | Year: 2011

Neoplasms of the nervous system, whether spontaneous or induced, are infrequent in laboratory rodents and very rare in other laboratory animal species. The morphology of neural tumors depends on the intrinsic functions and properties of the cell type, the interactions between the neoplasm and surrounding normal tissue, and regressive changes. The incidence of neural neoplasms varies with sex, location, and age of tumor onset. Although the onset of spontaneous tumor development cannot be established in routine oncogenicity studies, calculations using the time of diagnosis (day of death) have revealed significant differences in tumor biology among different rat strains. In the central nervous system, granular cell tumors (a meningioma variant), followed by glial tumors, are the most common neoplasms in rats, whereas glial cell tumors are observed most frequently in mice. Central nervous system tumors usually affect the brain rather than the spinal cord. Other than adrenal gland pheochromocytomas, the most common neoplasms of the peripheral nervous system are schwannomas. Neural tumors may develop in the central nervous system and peripheral nervous system from other cell lineages (including extraneural elements like adipose tissue and lymphocytes), but such lesions are very rare in laboratory animals.


Strupp C.,Harlan Laboratories Ltd.
Annals of Occupational Hygiene | Year: 2011

Beryllium metal was classified in Europe collectively with beryllium compounds, e.g. soluble salts. Toxicological equivalence was assumed despite greatly differing physicochemical properties. Following introduction of the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) regulation, beryllium metal was classified as individual substance and more investigational efforts to appropriately characterize beryllium metal as a specific substance apart from soluble beryllium compounds was required. A literature search on toxicity of beryllium metal was conducted, and the resulting literature compiled together with the results of a recently performed study package into a comprehensive data set. Testing performed under Organisation for Economic Co-Operation and Development guidelines and Good Laboratory Practice concluded that beryllium metal was neither a skin irritant, an eye irritant, a skin sensitizer nor evoked any clinical signs of acute oral toxicity; discrepancies between the current legal classification of beryllium metal in the European Union (EU) and the experimental results were identified. Furthermore, genotoxicity and carcinogenicity were discussed in the context of the literature data and the new experimental data. It was concluded that beryllium metal is unlikely to be a classical nonthreshold mutagen. Effects on DNA repair and morphological cell transformation were observed but need further investigation to evaluate their relevance in vivo. Animal carcinogenicity studies deliver evidence of carcinogenicity in the rat; however, lung overload may be a species-specific confounding factor in the existing studies, and studies in other species do not give convincing evidence of carcinogenicity. Epidemiology has been intensively discussed over the last years and has the problem that the studies base on the same US beryllium production population and do not distinguish between metal and soluble compounds. It is noted that the correlation between beryllium exposure and carcinogenicity, even including the soluble compounds, remains under discussion in the scientific community and active research is continuing.


Strupp C.,Harlan Laboratories Ltd.
Annals of Occupational Hygiene | Year: 2011

The toxicity of soluble metal compounds is often different from that of the parent metal. Since no reliable data on acute toxicity, local effects, and mutagenicity of beryllium metal have ever been generated, beryllium metal powder was tested according to the respective Organisation for Economical Co-Operation and Development (OECD) guidelines. Acute oral toxicity of beryllium metal was investigated in rats and local effects on skin and eye in rabbits. Skin-sensitizing properties were investigated in guinea pigs (maximization method). Basic knowledge about systemic bioavailability is important for the design of genotoxicity tests on poorly soluble substances. Therefore, it was necessary to experimentally compare the capacities of beryllium chloride and beryllium metal to form ions under simulated human lung conditions. Solubility of beryllium metal in artificial lung fluid was low, while solubility in artificial lysosomal fluid was moderate. Beryllium chloride dissolution kinetics were largely different, and thus, metal extracts were used in the in vitro genotoxicity tests. Genotoxicity was investigated in vitro in a bacterial reverse mutagenicity assay, a mammalian cell gene mutation assay, a mammalian cell chromosome aberration assay, and an unscheduled DNA synthesis (UDS) assay. In addition, cell transformation was tested in a Syrian hamster embryo cell assay, and potential inhibition of DNA repair was tested by modification of the UDS assay. Beryllium metal was found not to be mutagenic or clastogenic based on the experimental in vitro results. Furthermore, treatment with beryllium metal extracts did not induce DNA repair synthesis, indicative of no DNA-damaging potential of beryllium metal. A cell-transforming potential and a tendency to inhibit DNA repair when the cell is severely damaged by an external stimulus were observed. Beryllium metal was also found not to be a skin or eye irritant, not to be a skin sensitizer, and not to have relevant acute oral toxic properties.


Patent
Harlan Laboratories Inc. | Date: 2011-04-14

Hairless, immunodeficient mice on a non-obese diabetic (NOD) background and methods for their production are disclosed herein. The mice are hairless and have multiple immunodeficiencies, including B-cell and T-cell deficiencies, as well as impaired macrophage and complement function. The mice also have a further deficit in natural killer and dendritic cells of the immune system. The mice are useful for biomedical research, for example, in studies involving xenograft transplantation, spontaneous tumors, cancer cell tumorigenesis, tumor angiogenesis, tumor metastatic potential, tumor suppression therapy, carcinogenesis regulation, and tumor imaging.

Loading Harlan Laboratories Ltd. collaborators
Loading Harlan Laboratories Ltd. collaborators