Search

Body dissatisfaction and eating disorders are increasing on a global scale. It has been suggested that increasing access to globalised media maybe one factor in rising risk of eating disorders in low- and middle-income countries. We examined 3-dimensional body ideals, body satisfaction, and eating disorder risk in a population with relatively recent access to mass media. We find that although women in these communities maintain higher body weight ideals, and greater body appreciation, than Western women, those women who are internalising globalised cultural messaging about appearance are at greater risk of body dissatisfaction and, in turn, increased risk of eating disorders. This was true both when comparing between women and looking at how individual women’s attitudes varied over time. These data show that cultural messaging about appearance has implications for body image and eating disorder risk even in populations which do not have a long history of promoting thin ideals.

Tissue engineering is an increasingly popular method of addressing pathological disorders of cartilage. Recent studies have demonstrated its clinical efficacy, but there is little information on the structural organisation and biochemical composition of the repair tissue and its relation to the adjacent normal tissue. We therefore analysed by polarised light microscopy and immunohistochemistry biopsies of repair tissue which had been taken 12 months after implantation of autologous chondrocytes in two patients with defects of articular cartilage.Our findings showed zonal heterogeneity throughout the repair tissue. The deeper zone resembled hyaline-like articular cartilage whereas the upper zone was more fibrocartilaginous. The results indicate that within 12 months autologous chondrocyte implantation successfully produces replacement cartilage tissue, a major part of which resembles normal hyaline cartilage.

Fractions enriched in Photosystem 1 or Photosystem 2 activity have been isolated from the cyanobacterium Chlorogloea fritschii after extraction of the membranes with digitonin and Triton X-100. Separation of the extract into the two components was achieved by using a Sepharose 6B column, calibration of which gave Kd values of 0.3 for the Photosystem 1 fraction and 0.53 for Photosystem 2. These values corresponded to molecular weights of approx. 500000 and 90000 respectively. The Photosystem 1 particle was shown to aggregate on storage and EDTA was shown to be necessary to separate the Photosystem 1 and 2 fractions.

Chloroplasts or cells from maize (Zea mays) bundle sheath show a very low intensity of delayed light emission compared with mesophyll protoplasts or chloroplasts. The bundle-sheath chloroplasts retain only the fast (less than 1 ms) component of the emission. They also fail to show fluorescence induction in contrast to the mesophyll, which behaved normally. The mesophyll material could be made to resemble the bundle-sheath chloroplasts in respect of both phenomena by adding to it 1-(3′,4′-dichlorophenyl)-3,3-dimethyl-urea and hydroxylamine, together. It is concluded that Photosystem II, that gives rise to both effects, is not active in the bundle sheath but may be present in an inhibited form.

Ca2+ has been shown to be essential for the retention of maximal O2-evolving activity in Photosystem 2 particles extracted by using dodecyldimethylamine oxide from Anacystis nidulans thylakoids. The effect cannot entirely be mimicked by using Mg2+. Ca2+ stimulates electron transport from diphenylcarbazide to 2,6-dichloroindophenol catalysed by lead-inhibited cation-free preparations, showing the presence of two cation-binding sites in these particles. Photosystem 2 preparations extracted in Ca2+-containing buffer show the presence of three polypeptides at mol. wt. 30000, 33000 and 36000, which are absent or much decreased in preparations extracted in Mg2+-containing buffer. The calmodulin antagonist chlorpromazine inhibits activity of the Photosystem 2 preparation, suggesting the presence of a Ca2+-binding protein.

Substantial amounts of iron have been shown by Mössbauer spectroscopy to be present in Photosystem-I preparations from the blue-green alga Chlorogloeta fritschii. Changes in the spectra on chemical reduction provide evidence that some of this iron is very similar to that found in the 4Fe-4S centres of ferredoxins. Such reduced samples also show e.p.r. signals consistent with maximum reduction of iron-sulphur centres A and B of Photosystem I. An unchanged component in the spectra indicates, assuming all centres A and B are reduced, the presence of another iron-containing species.

At least two species of iron were identified in crude membrane preparations of the blue-green algae Chlorogloea fritschii and Anacystis nidulans by Mössbauer spectroscopy. One species was non-magnetic with chemical shift more characteristic of a ferredoxin-like centre than of any known low-spin Fe(II) biological compounds. Studies on cells grown under depleted-iron conditions show the other iron species to be part of the system for iron metabolic transport and/or storage.

In order to synthesize analogues of thromboxane A2 (I) the compounds (III) and (V) are prepared as shown.