In vitro antimicrobial susceptibility of Escherichia coli isolates from clinical bovine mastitis in Finland and Israel

Minimal inhibition concentration (MIC) values of 100 Finnish and 100 Israeli Escherichia coli isolated from clinical bovine mastitis were determined for ampicillin, cephalexin, ceftazidime, dihydrostreptomycin, gentamicin, tetracycline, trimethoprim-sulfadiazine, and ciprofloxacin by an agar dilution method. The in vitro antimicrobial susceptibility of the E. coli isolates was high; only 27% showed resistance to one or more tested antimicrobial agents. Fifteen percent of the Israeli isolates and 14% of the Finnish isolates were resistant to tetracycline, 3 and 16% to cephalexin, 10 and 7% to ampicillin, 13 and 9% to dihydrostreptomycin, and 4 and 2% to trimethoprim-sulfadiazine. No gentamicin-, ceftazidime-, or ciprofloxacin-resistant isolates were detected. Eleven percent of all the isolates were resistant to two or more antimicrobial agents. Tetracycline was most often associated with multiresistant patterns. Most of the multiresistant isolates had very high MIC values, whereas most of those that were resistant to only one tested antibiotic had MIC values close to the susceptibility breakpoint. Antimicrobial resistance appeared to pose no problem in E. coli isolated from mastitic milk of both countries. This is probably due to the controlled use of antimicrobial agents in the treatment of dairy herds. Some differences were present in the resistance patterns, which may reflect the different use of antimicrobial agents in these two countries.     

Effect of smokeless tobacco (snus) on smoking and public health in Sweden

Method: Narrative review of published papers and other data sources (for example, conference abstracts and internet based information) on snus use, use of other tobacco products, and changes in health status in Sweden.

Results: Snus is manufactured and stored in a manner that causes it to deliver lower concentrations of some harmful chemicals than other tobacco products, although it can deliver high doses of nicotine. It is dependence forming, but does not appear to cause cancer or respiratory diseases. It may cause a slight increase in cardiovascular risks and is likely to be harmful to the unborn fetus, although these risks are lower than those caused by smoking. There has been a larger drop in male daily smoking (from 40% in 1976 to 15% in 2002) than female daily smoking (34% in 1976 to 20% in 2002) in Sweden, with a substantial proportion (around 30%) of male ex-smokers using snus when quitting smoking. Over the same time period, rates of lung cancer and myocardial infarction have dropped significantly faster among Swedish men than women and remain at low levels as compared with other developed countries with a long history of tobacco use.

Conclusions: Snus availability in Sweden appears to have contributed to the unusually low rates of smoking among Swedish men by helping them transfer to a notably less harmful form of nicotine dependence.

     

Effects of Different Retention Parameter Estimation Methods on the Prediction of Surface Runoff Using the SCS Curve Number Method

Quantifying different hydrological components is an initial step for sustainable water resources planning and management. One rising concern is the conflict between the environment, hydropower and agriculture mainly in lowland areas where a large share of the base flows need to be abstracted. The Soil and Water Assessment Tool (SWAT) model was used to understand the hydrological processes of the Upper Awash River Basin with the emphasis on analyzing the different options for surface runoff generation using the Soil Conservation Service (SCS) Curve Number (CN) method. In this study, SWAT was applied incorporating two methods for estimating the retention parameter (S) for the SCS-CN method. The first allowed S to vary with soil profile moisture content (SM method) and the second allowed S to vary with accumulated plant evapotranspiration (PT method). Hydrograph comparison indicated that the PT method was better in simulating peak flows while the SM method was better in simulating the low flows. While the predicted stream flow hydrographs showed an agreement between the two methods, the simulated annual water balance indicated a disagreement in quantifying the different hydrological components. After evapotranspiration, base flow was the dominant component simulated in the SM method whereas surface runoff was the foremost in the PT method simulation. The analysis indicated that care must be taken when selecting an appropriate tool for quantifying hydrologic system to be used for decision making especially for un-gauged catchments where validation of model results is not possible.     

Indikatorenbasierte Evaluierung von Fischhabitaten in alpinen Fließgewässern

The EU Water Framework Directive commits member states to achieve good ecological status in all waterbodies. Artificial or heavily modified waterbodies must reach at least its good ecological potential. In view of these requirements, simple and feasible methods are required in order to evaluate habitat suitability for relevant target species in larger river reaches. Well-developed models for determining the relationship between stream flows and habitat for target species mainly based on micro- and meso-scale already exist. However, the application of such models is complex and time-consuming and consequently limited to relatively short river segments. The objective of this study is to develop a simplified applicable assessment model to evaluate habitat conditions for selected target fish. This model uses hydro-morphological indicators for the habitat assessment and relies on correlative relations between habitat suitability and hydro-morphological features of river stretches (average Froude-number, relative flow width, mean bed slope, relative water depth and flow velocity). The indicators were determined as reach-related averages, derived from 2D model simulations (hydraulic and habitat-specific). Particular emphasis was laid on using a wide range of river stretches with different hydro-morphological characteristics (hydrology, bed substratum, bed structures, degree of braiding, sinuosity of the river course, mean bed width and bed slope). As a result, a set of model equations enables the evaluation of fish habitat conditions in river stretches as a function of flow and morphology. The habitat suitability assessment focuses on four preselected target species: brown trout, European grayling and for low slope rivers common nase and barbel.     

Effects of the mycotoxin deoxynivalenol on human primary hepatocytes

Toxic effects of the mycotoxin deoxynivalenol (DON) observed in animals range from diarrhea, vomiting, gastro-intestinal inflammation to necrosis of several tissues. In the last years, DON has been tested in hepatocytes of several animal species for its cytotoxicity. However, these tests are limited to the use of animal cells. No studies using human hepatocytes are available. Further investigations with the human hepatocellular liver carcinoma cell line HepG2 might be limited due to the disadvantages of cell lines (e. g. immortalization, tumor derivation, longtime cultivation) and do not necessarily reflect the response of normal human cells. In order to overcome this problem and to be closer to the human situation, we studied the effect of DON in human primary hepatocytes and compared these data to the effects in the HepG2 cell line. Cell viability, apoptotic and necrotic cell death, albumin secretion and metabolic activity were determined. It could be demonstrated that DON has a distinct cytotoxic effect on human primary hepatocytes. Viability, protein content and albumin secretion were reduced in a dose-dependent manner. The apoptotic key enzyme caspase-3 was activated, while LDH release occurred only after long incubation time due to a secondary necrosis. Furthermore, we studied the metabolism of DON using LC-MS/MS. DON was neither metabolized by primary hepatocytes cells nor by the HepG2 cell line.     

Internal doses of acrylamide and glycidamide in mice fed diets with low acrylamide contents

The formation of acrylamide during heating of certain foodstuffs constitutes a potential health hazard. The health risk assessment should be based on knowledge about the relation between dietary exposure to acrylamide and internal doses of acrylamide and its genotoxic metabolite glycidamide. The primary aim of this study in mice was to measure these relationships at low levels of acrylamide intake through the diet. A secondary aim was to clarify which extraction method should be used when analyzing acrylamide in food in order to obtain a correct measure of the acrylamide that is available for absorption. In the analysis procedure, alkaline extraction has earlier shown much higher measured acrylamide levels in certain foods compared to water extraction. In this subcronic study the administered diets were composed to give five levels of acrylamide intakes between 3 and 50 mug/kg body weight per day (calculated on figures obtained after water extraction). Internal doses of acrylamide and glycidamide were measured through hemoglobin (Hb)-adducts. The results showed linear relationships between the exposure of acrylamide and Hb-adduct levels from both acrylamide and glycidamide at these low exposure levels. The study also showed that the "extra" acrylamide measured with alkaline extraction does not correspond to bioavailable acrylamide.     

Validation of the performance of a GMO multiplex screening assay based on microarray detection

A new screening method for the detection and identification of GMO, based on the use of multiplex PCR followed by microarray, has been developed and is presented. The technology is based on the identification of quite ubiquitous GMO genetic target elements first amplified by PCR, followed by direct hybridisation of the amplicons on a predefined microarray (DualChip^® GMO, Eppendorf, Germany). The validation was performed within the framework of a European project (Co-Extra, contract no 007158) and in collaboration with 12 laboratories specialised in GMO detection. The present study reports the strategy and the results of an ISO complying validation of the method carried out through an inter-laboratory study. Sets of blind samples were provided consisting of DNA reference materials covering all the elements detectable by specific probes present on the array. The GMO concentrations varied from 1% down to 0.045%. In addition, a mixture of two GMO events (0.1% RRS diluted in 100% TOPAS19/2) was incorporated in the study to test the robustness of the assay in extreme conditions. Data were processed according to ISO 5725 standard. The method was evaluated with predefined performance criteria with respect to the EC CRL method acceptance criteria. The overall method performance met the acceptance criteria; in particular, the results showed that the method is suitable for the detection of the different target elements at 0.1% concentration of GMO with a 95% accuracy rate. This collaborative trial showed that the method can be considered as fit for the purpose of screening with respect to its intra- and inter-laboratory accuracy. The results demonstrated the validity of combining multiplex PCR with array detection as provided by the DualChip^® GMO (Eppendorf, Germany) for the screening of GMO. The results showed that the technology is robust, practical and suitable as a screening tool.     

Randomised trial investigating effect of a novel nicotine delivery device (Eclipse) and a nicotine oral inhaler on smoking behaviour, nicotine and carbon monoxide exposure, and motivation to quit

OBJECTIVE: To monitor the effect of a novel nicotine delivery device that may produce fewer carcinogens (Eclipse) on cigarette smoking, carbon monoxide and nicotine concentrations, and motivation to give up smoking. The smoker's own brand of cigarette and a nicotine replacement product (Nicotrol inhaler) were used as comparisons. DESIGN: After baseline data were recorded, smokers were randomised to either Eclipse or inhaler for two weeks and then switched to the other product for another two weeks. Thereafter a second baseline was obtained. SETTING AND PARTICIPANTS: Fifty smokers were included and data are reported for the 40 with complete data sets. The smokers were not trying to quit but were interested in trying a new product to reduce their risk. They visited a smoking clinic 10 times during the six week period of the trial. INTERVENTION: No counselling to aid reduction by Eclipse or inhaler was given. MAIN OUTCOME MEASURES: At each visit smoking status and carbon monoxide concentrations were recorded. In half of the visits withdrawal symptoms, attitudes towards smoking, heart rate, and blood nicotine concentrations were also recorded. RESULTS: Eclipse use decreased the number of cigarettes smoked per day (cpd) from 19.1 cpd at baseline to 2.1 cpd (p < 0.001), but increased carbon monoxide concentrations in parts per million (ppm) from 21.0 ppm to 33.0 ppm (p < 0.001). A similar decrease in cigarettes smoked per day was seen with the Nicotrol inhaler, from 19.1 cpd to 4.8 cpd (p < 0.001), but carbon monoxide decreased from 21.0 ppm to 12.7 ppm (p < 0.001). The blood nicotine concentration remained fairly stable with Eclipse, increasing slightly from 16.8 ng/ml to 18.0 ng/ml, while for the inhaler a significant drop was noted, from 16.8 ng/ml to 12. 2 ng/ml (p < 0.002). Craving and withdrawal did not increase with Eclipse. Few significant adverse events occurred with Eclipse. CONCLUSIONS: Eclipse can dramatically decrease cigarette consumption without causing withdrawal symptoms or decreases in nicotine concentrations or motivation to quit altogether. Unlike the inhaler, Eclipse produces an increase in carbon monoxide concentration. Thus Eclipse may not be a safer cigarette.     

Effect of rabbit kappa-casein expression on the properties of milk from transgenic mice

Transgenic mice were produced carrying the coding region of the rabbit kappa-casein gene linked to the upstream region of the rabbit whey acidic protein gene. Mice from the highest-expressing line produced 2.5 mg rabbit kappa-casein/ml in their milk. The foreign protein was associated with the casein micelles and altered micelle size, though in the high-expressing line rabbit kappa-casein also segregated into the whey fraction obtained after centrifuging the milk samples. Milk from transgenic mice had the same overall protein content as that from non-transgenic mice, except for the transgene product. However, litters fed with this transgenic mouse milk grew less well than litters given milk from non-transgenic mice. This reduction in growth was not related to changes in mammary gland structure or mammary cell morphology. Preliminary results indicated that milk from the transgenic mice had a higher viscosity.     

Development and experimental validation of a frying model to estimate acrylamide levels in French fries

ABSTRACT:  In this study, a numerical model was developed to simulate frying of potato strips and estimate acrylamide levels in French fries. Heat and mass transfer parameters determined during frying of potato strips and the formation and degradation kinetic parameters of acrylamide obtained with a sugar–asparagine model system were incorporated within the model. The effect of reducing sugar content (0.3 to 2.15 g/100 g dry matter), strip thickness (8.5 × 8.5 mm and 10 × 10 mm), and frying time (3, 4, 5, and 6 min) and temperature (150, 170, and 190 °C) on resultant acrylamide level in French fries was investigated both numerically and experimentally. The model appeared to closely estimate the acrylamide contents, and thereby may potentially save considerable time, money, and effort during the stages of process design and optimization.