Experimental osteoarthritis in the rabbit. III. Acute osteoarthritis: subchondral P02 and oxygen consumption and diffusion capacity in the synovial membrane

The earliest sign of osteoarthritis is acute synovitis with joint effusion and elevated intraarticular pressure, which causes compression of the intracapsular vein segments draining the epiphyseal bone compartment. The increased outflow resistance may cause a fall in the regional blood flow and thereby lead to a state of tissue hypoxia. The acute osteoarthritis may also affect the transfer of oxygen to the cartilage across synovial membrane because of the extensive inflammation with hypercellularity and edema.In the present study we have investigated the subchondral P₀₂ and P_c02 in acute osteoarthritis. There was no significant difference between these gas tensions in the normal and osteoarthritic bone. We have also investigated the oxygen consumption and diffusion capacity in the synovial membrane. The latter was decreased by a factor of 4 in the osteoarthritic joints whilst the oxygen consumption was increased by a factor of 3.     

Geographical and botanical variation in concentrations of copper,molybdenum, sulphur and iron in sheep pasture plants in Norway

Abstract

To obtain a better knowledge basis for the correct supply of Cu to sheep in Norway, a systematic, countrywide investigation of element composition of pasture plants was conducted, with emphasis on natural pastures. Samples of pasture grass, herbs, willow shrub leaves and bilberry (N = 575) from 142 locations were analysed for Cu, Mo, S and Fe. A large geographical variation was observed for Mo concentration and Cu:Mo ratio, a somewhat smaller variation for Fe, while Cu and S concentrations showed limited geographical variation. The Mo variation led to a Cu:Mo ratio <2 in 2% of the samples and >20 in 62% of samples, confirming that the trace element composition of Norwegian sheep pastures may represent a risk of Cu deficiency as well as Cu overload, depending on location. A considerable botanical variation was also observed, in particular for Cu and Mo.     

Geographical and botanical variation in concentrations of selenium,cobalt, iodine,zinc and other essential elements in sheep pasture plants in Norway

Abstract

In order to obtain a more comprehensive knowledge basis for the supply of essential elements to sheep on pasture in Norway, a systematic, countrywide investigation of element composition of pasture plants was conducted, with emphasis on natural pastures. Samples of pasture grass, herbs, willow shrub leaves and bilberry (N = 575) from 142 locations were analysed for the essential trace elements Se, Co, I, Zn and Mn, and for the major elements Ca, P, Mg, Na and K. A large and systematic geographical variation was observed for Se, I and Na, while concentrations of Zn and of most major elements showed limited variation with sampling site. Se concentrations were inadequate in the majority of samples from all plant species. Marked botanical variation was noted for Co and Zn, and willow shrub leaves were identified as a valuable source of these elements in natural sheep pastures.     

Cross-sectional study on acrylamide hemoglobin adducts in subpopulations from the European Prospective Investigation into Cancer and Nutrition (EPIC) Study

Acrylamide exposure was investigated in subgroups of the EPIC study population (510 subjects from 9 European countries, randomly selected and stratified by age, gender, and smoking status) using hemoglobin adducts of acrylamide (HbAA) and its primary metabolite glycidamide (HbGA). Blood samples were analyzed for HbAA and HbGA by HPLC/MS/MS. Statistical models for HbAA and HbGA were developed including body mass index (BMI), educational level, and physical activity. A large variability in acrylamide exposure and metabolism between individuals and country groups was observed with HbAA and HbGA values ranging between 15-623 and 8-377 pmol/g of Hb, respectively. Both adducts differed significantly by country, sex, and smoking status. HbGA values were significantly lower in high alcohol consumers than in moderate consumers. With increasing BMI, HbGA in nonsmokers and HbAA in smokers decreased significantly. In the assessment of potential health effects related to acrylamide exposure, country of origin, BMI, alcohol consumption, sex, and smoking status should be considered.     

Bioindication and modelling of atmospheric deposition in forests enable exposure and effect monitoring at high spatial density across scales

Key message

Moss surveys provide spatially dense data on environmental concentrations of heavy metals and nitrogen which, together with other biomonitoring and modelling data, can be used for indicating deposition to terrestrial ecosystems and related effects across time and areas of different spatial extension.

Context

For enhancing the spatial resolution of measuring and mapping atmospheric deposition by technical devices and by modelling, moss is used complementarily as bio-monitor.

Aims

This paper investigated whether nitrogen and heavy metal concentrations derived by biomonitoring of atmospheric deposition are statistically meaningful in terms of compliance with minimum sample size across several spatial levels (objective 1), whether this is also true in terms of geostatistical criteria such as spatial auto-correlation and, by this, estimated values for unsampled locations (objective 2) and whether moss indicates atmospheric deposition in a similar way as modelled deposition, tree foliage and natural surface soil at the European and country level, and whether they indicate site-specific variance due to canopy drip (objective 3).

Methods

Data from modelling and biomonitoring atmospheric deposition were statistically analysed by means of minimum sample size calculation, by geostatistics as well as by bivariate correlation analyses and by multivariate correlation analyses using the Classification and Regression Tree approach and the Random Forests method.

Results

It was found that the compliance of measurements with the minimum sample size varies by spatial scale and element measured. For unsampled locations, estimation could be derived. Statistically significant correlations between concentrations of heavy metals and nitrogen in moss and modelled atmospheric deposition, and concentrations in leaves, needles and soil were found. Significant influence of canopy drip on nitrogen concentration in moss was proven.

Conclusion

Moss surveys should complement modelled atmospheric deposition data as well as other biomonitoring approaches and offer a great potential for various terrestrial monitoring programmes dealing with exposure and effects.

     

Experimental osteoarthritis in the rabbit. II. A new method to estimate the oxygen consumption and diffusion capacity in the synovial membrane of the knee

The oxygen supply to the joint cartilage depends on the oxygen transport from the capsular arteries to the capillaries, the oxygen diffusion across the synovial membrane and the oxygen transport through the synovia. In osteoarthritis the resistance to transport across all 3 barriers may be increased because of the joint effusion, the elevated intraarticular pressure and the inflammatory changes of the synovial membrane.In the present study we describe a method to determine 2 important parameters affecting the oxygen transport through the synovial membrane: the oxygen consumption and diffusion capacity of the membrane. The principle of the method is to perfuse the joint cavity of the knee by saline saturated with air and to record the relationship between the oxygen partial pressure in the outflowing perfusate and the perfusion rate.The values found for the diffusion capacity and oxygen consumption were 0.039 ± 0.013 μl O₂/min/Torr and 0.93 ± 0.90 μl O₂/min (mean ± s).     

Metals in Main Rivers of Azerbaijan: Influence of Transboundary Pollution

Silver, arsenic, cadmium, chromium, cobalt, copper, mercury, lead, and zinc were determined monthly during 2004–2008 at 11 sites in the Kura–Araks river system, Azerbaijan. Suspended fractions of the elements were studied at the five sites experiencing the highest load. Metal concentrations varied moderately at each site but differed substantially between sites. Sites near the borders with Armenia and Georgia were most polluted, both with respect to soluble concentrations and percentage transported in suspended form. Lower parts of the Kura river were shielded from metal contamination by an upstream reservoir acting as a metal trap. Corresponding removal was not evident in Araks, its main tributary, where particularly high concentrations of arsenic were observed. At the most contaminated sites, more than 60% of cadmium, cobalt, chromium, copper, manganese, nickel, lead, and zinc was transported in suspended form whereas arsenic and molybdenum occurred mainly in soluble form. Dynamics of metals in the Kura–Araks water/sediment system should be further studied to meet future problems.