Osteoarthritis and a high-fat diet: the full 'OA syndrome' in a small animal model

Obesity is one of the main risk factors for osteoarthritis (OA) and due to the global rise in obesity this will increasingly contribute to OA development. The article of Griffin and co-workers in this issue of Arthritis Research and Therapy shows that a high-fat diet leads to obesity and OA in the studied animals and that this is related to alterations in locomotor function. Furthermore, a high-fat diet leads to pain sensitization and depression/anxiety-like behavior unrelated to structural OA changes in the knee. Their findings demonstrate that the majority of features of the human 'OA syndrome' can be reproduced in a small animal model

Visible diode lasers can be used for flow cytometric immunofluorescence and DNA analysis

This report describes a feasibility study concerning the use of a visible diode laser for two important fluorescence applications in a flow cytometer. With a 3 mW 635 nm. diode laser, we performed immunofluorescence measurements using the fluorophore allophycocyanin (APC). We have measured CD8 positive lymphocytes with a two-step labeling procedure and the resulting histograms showed good separation between the negative cells and the dim and the bright fluorescent subpopulations. As a second fluorescence application, we chose DNA analysis with the recently developed DNA/ RNA stains TOTO-3 and TO-PRO-3. In our setup TO-PRO-3 yielded the best results with a CV of 3.4%. Our results indicate that a few milliwatts of 635 nm light from a visible diode laser is sufficient to do single color immunofluorescence measurements with allophycocyanin and DNA analysis with TO-PRO-3. The major advantages of using a diode laser in a flow cytometer are the small size, the low price, the high efficiency, and the long lifetime

A role for age-related changes in TGFβ signaling in aberrant chondrocyte differentiation and osteoarthritis

Transforming growth factor beta (TGFβ) is a growth factor with many faces. In our osteoarthritis (OA) research we have found that TGFβ can be protective as well as deleterious for articular cartilage. We postulate that the dual effects of TGFβ on chondrocytes can be explained by the fact that TGFβ can signal via different receptors and related Smad signaling routes. On chondrocytes, TGFβ not only signals via the canonical type I receptor ALK5 but also via the ALK1 receptor. Notably, signaling via ALK5 (Smad2/3 route) results in markedly different chondrocyte responses than ALK1 signaling (Smad1/5/8), and we postulate that the balance between ALK5 and ALK1 expression on chondrocytes will determine the overall effect of TGFβ on these cells. Importantly, signaling via ALK1, but not ALK5, stimulates MMP-13 expression by chondrocytes. In cartilage of ageing mice and in experimental OA models we have found that the ALK1/ALK5 ratio is significantly increased, favoring TGFβ signaling via the Smad1/5/8 route, changes in chondrocyte differentiation and MMP-13 expression. Moreover, human OA cartilage showed a significant correlation between ALK1 and MMP-13 expression. In this paper we summarize concepts in OA, its link with ageing and disturbed growth factor responses, and a potential role of TGFβ signaling in OA development

Herziening spieringadvisering

Het huidige spieringprotocol voor de openstelling van de visserij op spiering in het IJsselmeer en Markermeer-IJmeer dateert uit 1997 en is herzien in 2007. Het ministerie van LNV heeft aan WMR gevraagd om een advies over de herziening van het huidige afwegingskader (protocol). In 2013 is ook geprobeerd het protocol aan te passen, waarbij is geadviseerd om dit te doen door middel van een ecosysteemmodel (Osmose). Het model bleek niet uitvoerbaar omdat niet alle hiervoor benodigde gegevens en kennis aanwezig was. Om die reden is er nu een meer pragmatische en eenvoudiger aanpak toegepast

Prenatal diagnosis of isovaleric acidaemia by enzyme and metabolite assay in the first and second trimesters

Isovaleric acidaemia (IVA) is caused by a deficiency of isovaleryl CoA dehydrogenase. The diagnosis can be established biochemically by the demonstration of increased levels of isovalerylglycine (IVG) and 3-hydroxyisovaleric acid in urine and by the deficiency of incorporation of radiolabel from [14C]isovaleric acid in macromolecules in cultured fibroblasts. This paper reports a consecutive series of 24 prenatal diagnoses in pregnancies at high risk, using both methods-metabolite and indirect enzyme assay. Affected fetuses were diagnosed in four pregnancies: three in the second trimester and one recent case in the first trimester. The latter represents the first reported case of a first-trimester diagnosis of IVA by direct analysis of chorionic villi. We also report the first demonstration of strongly accumulated IVG in the amniotic fluid in the 12th week of an affected pregnancy

Deep CCD Surface Photometry of the Edge-On Spiral NGC 4244

We have obtained deep surface photometry of the edge-on spiral galaxy NGC 4244. Our data reliably reach 27.5 R magnitude arcsec^{-2}, a significant improvement on our earlier deep CCD surface photometry of other galaxies. NGC 4244 is a nearby Scd galaxy whose total luminosity is approximately one magnitude fainter than the peak of the Sc luminosity function. We find that it has a simple structure: a single exponential disk, with a scale height h_Z = 246 +/- 2 pc, a scale length h_R = 1.84 +/- 0.02 kpc and a disk cutoff at a radius R(max) = 10.0 kpc (5.4 scale lengths). We confirm a strong cutoff in the stellar disk at R(max), which happens over only 1 kpc. We do not see any statistically significant evidence for disk flaring with radius. Unlike the more luminous Sc galaxies NGC 5907 and M 33, NGC 4244 does not show any evidence for a second component, such as a thick disk or halo, at mu(R) < 27.5 magnitude arcsec^{-2}.Comment: 36 pages, including 12 figures; accepted for publication in Sept 99 A

Giant deer (Megaloceros giganteus) diet from Mid-Weichselian deposits under the present North Sea inferred from molar-embedded botanical remains

The molar of a giant deer, Megaloceros giganteus (Blumenbach, 1799), was discovered in sandy deposits of the North Sea, about 10 km west of the present shoreline of the Netherlands. Compacted masticated plant remains were preserved in the molar's deep folds. A palaeoecological analysis of these plant remains shows the complete dominance of pollen from Artemisia (sage) and other Asteraceae Tubuliflorae (Compositae), indicating that the animal foraged in a steppe environment, and may have preferred to eat Artemisia, which contain a high level of nutrients such as calcium and phosphorous components, which are important for antler building. Radiocarbon dating indicates that the plant remains are of mid‐Weichselian age [38 570 (+300, −290) 14C a BP, Greenland Interstadial‐11]. This is the first study of the food choice of M. giganteus based on palaeoecological evidence. We hypothesize about links between the extirpation of M. giganteus at the onset of the Holocene in North‐West Europe and the transition from a landscape with highly dynamic geomorphological processes and consequently prevalence of immature and nutrient‐rich soils, to a less dynamic landscape with stable, leached and acidifying soils, and the decline of Artemisia and other calciphilous plants

Oxidation of cellulose in pressurized carbon dioxide

This work presents first results upon oxidation of type II cellulose by nitrogen dioxide dissolved in carbon dioxide at high pressure. This reaction leads to oxidized cellulose, a natural-based bioresorbable fabric used for biomedical applications. The oxidation reaction takes place in a heterogeneous fluid–solid system. Kinetics of oxidation is presented here and effects of operating conditions such as pressure, temperature and initial moisture content of cellulose are investigated. Results are presented in terms of degree of oxidation of cellulose and quality of the final oxidized cellulose, which has been characterized using liquid-state and solid-state 13C NMR. The experimental results show the existence of possible secondary reactions which may lead to oxidized cellulose with insufficient mechanical strength. An attempt is made to evidence and understand the role of CO2 as a solvent in this system. Indeed, although supercritical CO2 appears to be a suitable candidate as a solvent for oxidation reactions, some inhibiting effect on nitrogen dioxide activity are observed in this case