Distribution of hyaluronan in articular cartilage as probed by a biotinylated binding region of aggrecan

The proportion of total tissue hyaluronan involved in interactions with aggrecan and link protein was estimated from extracts of canine knee articular cartilages using a biotinylated hyaluronan binding region-link protein complex (bHABC) of proteoglycan aggregate as a probe in an ELISA-like assay. Microscopic sections were stained with bHABC to reveal free hyaluronan in various sites and zones of the cartilages. Articular cartilage, cut into 20 m-thick sections, was extracted with 4 M guanidinium chloride (GuCl). Aliquots of the extract (after removing GuCl) were assayed for hyaluronan, before and after papain digestion. The GuCl extraction residues were analyzed after solubilization by papain. It was found that 47–51% of total hyaluronan remained in the GuCl extraction residue, in contrast to the 8–15% of total proteoglycans. Analysis of the extract revealed that 24–50% of its hyaluronan was directly detecable with the probe, while 50–76% became available only after protease digestion. The extracellular matrix in cartilage sections was stained with the bHABC probe only in the superficial zone and the periphery of the articular surfaces, both sites known to have a relatively low proteoglycan concentration. Trypsin pretreatment of the sections enhanced the staining of the intermediate and deep zones, presumably by removing the steric obstruction caused by the chondroitin sulfate binding region of aggrecans. Enhanced matrix staining in these zones was also obtained by a limited digestion with chondroitinase ABC. The results indicate that a part of cartilage hyaluronan is free from endogenous binding proteins, such as aggrecan and link protein, but that the chondroitin sulfate-rich region of aggrecan inhibits its probing in intact tissue sections. Therefore, hyaluronan staining was more intense in cartilage areas with lower aggrecan content. A large proportion of hyaluronan resists GuCl extraction, even from 20-m-thick tissue sections.     

Serum concentrations of the N-terminal propeptide of type III procollagen and two type IV collagen fragments and gene expression of the respective collagen types in liver in rats with dimethylnitrosamine-induced hepatic fibrosis.

Dimethylnitrosamine (DMN)-induced liver fibrosis was used as an experimental model to study the relationship between serum concentrations of the N-terminal propeptide of type III procollagen [S-Pro(III)-N-P] and the N-terminal (S-7S) and C-terminal (S-NC1) domains of type IV collagen and hepatic concentrations of type III and IV collagen mRNAs. Increases in S-Pro(III)-N-P, and especially in the two type IV collagen-related antigens, were found to be early events in the formation of DMN-induced hepatic fibrosis. The mean concentration of S-Pro(III)-N-P was 120% of the control mean on day 7 of DMN treatment, 230% on day 14 and 250% on day 21. The corresponding values for S-7S were 260, 950 and 1100% and, for S-NC1, 310, 820 and 1000%. All these changes were very similar to those found in the hepatic concentrations of the respective mRNAs. These data support a previous suggestion that an enhanced production of basement-membrane (type IV) collagen is an early event in the development of the DMN-induced hepatic fibrosis. The results also indicate that S-7S and S-NC1 are very sensitive indicators of changes in type IV collagen metabolism. Data obtained in gel-filtration experiments for these three serum antigens were consistent with the suggestion that all three antigens are mainly derived from the synthesis of the respective collagens.     

A gas chromatographic method for the determination of inositol monophosphates in rat brain

Regional levels of cerebral inositol-1-phosphate (Ins1P), an intermediate in phosphoinositide (PI) cycle, were readily detected with a new gas chromatographic (GC) method. GC analysis of trimethylsilyated Ins1P and myo-inositol-2-phosphate with a fused silica capillary SE-30 column and flame ionization detection was linear at picomolar range (pmol/l) with a sensitivity to a level of 2 pmol. Also, inositol monophosphates and glucose-6-phosphate are separated in unstimulated brain tissue. The mean recovery of the method is 98±5.2%. Ins 1P levels were higher in frontal than in caudal regions in control brains. Lithium treatment increased the levels of Ins1P throughout the brain but mostly in frontal brain regions and in the hippocampus. The present GC assay to measure the accumulation of Ins1P, an index for the activity of PI signalling, may be suitable for exploring regional differences in cerebral receptor-coupled PI signalling in vivo.     

Long Term Effect on Professionals’ Knowledge,Practice and Attitudes towards User Involvement Four Years after Implementing an Organisational Development Plan: A Controlled Study

Background

Health service organisations are increasingly implementing user involvement initiatives according to requirements from governments, such as user representation in administrational boards, better information to users, and more involvement of the users during treatment. Professionals are vital in all initiatives to enhance user involvement, and initiatives to increase involvement should influence the professionals’ practice and attitudes. The implementation of a development plan intending to enhance user involvement in a mental health hospital in Central Norway had no effect on the professionals after 16 months. The objective was therefore to investigate the long term effect on the professionals’ knowledge, practice and attitudes towards user involvement after four years.

Methods

This was a non-randomized controlled study including professionals from three mental health hospitals in Central Norway. A development plan intended to enhance user participation was implemented in one of the hospitals, including establishing a patient education centre and a user office, purchasing of user expertise, appointing contact professionals for next of kin, and improving of the centre’s information and the professional culture. The professionals at two other hospitals constituted the control group. All professionals were invited to answer the Consumer Participation Questionnaire (CPQ) and additional questions, at a four year interval.

Results

A total of 399 professionals participated (43% response rate). Comparing the changes in the intervention group with the changes in the control group, the results showed that the plan had improved some aspects of the professionals’ knowledge about the user involvement taking place in the hospital. In addition, some parts of the professionals’ practice of providing information to the service users was improved, and the development plan might have raised their awareness about insufficient involvement of next of kin.

Conclusions

This is the first controlled study on the long term effect on professionals from implementing a development plan to enhance user participation in a mental health hospital. Since there was more effect after four years than after 16 months, this study indicates that it takes time before the effect of complex interventions to enhance patient participation in organisations can be detected among the professionals. More long-term studies are thus warranted.     

Comparative Phylogeography in Rainforest Trees from Lower Guinea,Africa

Comparative phylogeography is an effective approach to assess the evolutionary history of biological communities. We used comparative phylogeography in fourteen tree taxa from Lower Guinea (Atlantic Equatorial Africa) to test for congruence with two simple evolutionary scenarios based on physio-climatic features 1) the W-E environmental gradient and 2) the N-S seasonal inversion, which determine climatic and seasonality differences in the region. We sequenced the trnC-ycf6 plastid DNA region using a dual sampling strategy: fourteen taxa with small sample sizes (dataset 1, mean n = 16/taxon), to assess whether a strong general pattern of allele endemism and genetic differentiation emerged; and four taxonomically well-studied species with larger sample sizes (dataset 2, mean n = 109/species) to detect the presence of particular shared phylogeographic patterns. When grouping the samples into two alternative sets of two populations, W and E, vs. N and S, neither dataset exhibited a strong pattern of allelic endemism, suggesting that none of the considered regions consistently harboured older populations. Differentiation in dataset 1 was similarly strong between W and E as between N and S, with 3–5 significant F _ST tests out of 14 tests in each scenario. Coalescent simulations indicated that, given the power of the data, this result probably reflects idiosyncratic histories of the taxa, or a weak common differentiation pattern (possibly with population substructure) undetectable across taxa in dataset 1. Dataset 2 identified a common genetic break separating the northern and southern populations of Greenwayodendron suaveolens subsp. suaveolens var. suaveolens, Milicia excelsa, Symphonia globulifera and Trichoscypha acuminata in Lower Guinea, in agreement with differentiation across the N–S seasonal inversion. Our work suggests that currently recognized tree taxa or suspected species complexes can contain strongly differentiated genetic lineages, which could lead to misinterpretation of phylogeographic patterns. Therefore the evolutionary processes of such taxa require further study in African tropical rainforests.     

Genetic relatedness among worker nestmates of three formicine slave-making ants

Summary We estimated genetic relatedness among worker nestmates of the facultative slave-making antFormica subnuda (28 colonies), and the obligate slavemakers F. subintegra (19 colonies) andPolyergus breviceps (14 colonies) using horizontal starch gel electrophoresis. Relatedness among nestmates was 0.42 inF. subnuda, 0.70 inF. subintegra, and 0.49 inP. breviceps on average. Relatedness ofF. subintegra workers did not differ significantly from 0.75 indicating that this species is monogynous, though some females may mate multiply. The estimates ofF. subnuda andP. breviceps were significantly lower than 0.75 and, consequently, colonies were polygynous and/or poly-androus. The inbreeding coefficients were close to zero in all species suggesting random mating. We suggest that owing to practical monogyny and obligate nature of its slavemaking,F. subintegra is a good species for tests of sex allocation theory.     

A recent local sweep at the PHYA locus in the Northern European Spiterstulen population of Arabidopsis lyrata

Northern and central European Arabidopsis lyrata ssp. petraea populations are locally adapted to prevailing climatic conditions through differences in timing of life history events. The timing of flowering and, in perennials, the timing of growth cessation influence fitness. Phytochrome A may have an important role in regulating these life history traits as it perceives changes in daylength. We asked whether PHYA has contributed to local adaptation to the northern conditions in A. l. petraea. To search for signals of directional selection at the PHYA locus, we resequenced PHYA and 9 short fragments around PHYA from a 57‐kb region from a German (Plech) and a Norwegian (Spiterstulen) population and compared patterns of differentiation and diversity to a set of 19 reference loci around the genome. First, we found that the populations were highly differentiated: there were three nonsynonymous fixed differences at the PHYA locus, which was in stark contrast with the total four fixed differences in the 19 reference loci. Compatible with a sweep hypothesis, variation was almost completely removed from the 9.4‐kb region around PHYA in the northern Spiterstulen population. The overall level of linkage disequilibrium (LD) was higher in Spiterstulen, but there was no LD across the PHYA locus in the population, which is also a known consequence of a selective sweep. The sweep has likely occurred after the last glacial maximum, which suggests that it has contributed to adaptation to the northern conditions.     

Origin and diversification of the Greater Cape flora: ancient species repository, hot-bed of recent radiation, or both?

Like island-endemic taxa, whose origins are expected to postdate the appearance of the islands on which they occur, biome-endemic taxa should be younger than the biomes to which they are endemic. Accordingly, the ages of biome-endemic lineages may offer insights into biome history. In this study, we used the ages of multiple lineages to explore the origin and diversification of two southern African biomes whose remarkable floristic richness and endemism has identified them as global biodiversity hotspots (succulent karoo and fynbos). We used parsimony optimization to identify succulent karoo- and fynbos-endemic lineages across 17 groups of plants, for which dated phylogenies had been inferred using a relaxed Bayesian (BEAST) approach. All succulent karoo-endemic lineages were less than 17.5 My old, the majority being younger than 10 My. This is largely consistent with suggestions that this biome is the product of recent radiation, probably triggered by climatic deterioration since the late Miocene. In contrast, fynbos-endemic lineages showed a broader age distribution, with some lineages originating in the Oligocene, but most being more recent. Also, in groups having both succulent karoo- and fynbos-endemic lineages, there was a tendency for the latter to be older. These patterns reflect the greater antiquity of fynbos, but also indicate considerable recent speciation, probably through a combination of climatically-induced refugium fragmentation and adaptive radiation.