EFFECT OF VITAMIN E SUPPLEMENTATION AND PARTIAL SUBSTITUTION OF POLY- WITH MONO-UNSATURATED FATTY ACIDS IN PIG DIETS ON MUSCLE,AND MICROSOME EXTRACT a-TOCOPHEROL CONCENTRATION AND LIPID OXIDATION

The experiment was organized in a 3×2 factorial arrangement with three dietary fat blends and a basal (20 mg kg^?1 diet) or supplemented (220 mg kg^?1) level of α-tocopheryl acetate. Dietary vitamin E and monounsaturated to polyunsaturated fatty acid ratio (dietary MUFA/PUFA) affected muscle α-tocopherol concentration (α-tocopherol [log μg g^?1]=0.18 (±0.105)+0.0034 (±0.0003)·dietary α-tocopherol [mg kg^?1 diet] (P<0.0001)+0.39 (±0.122)·dietary MUFA/PUFA (P<0.0036)). An interaction between dietary α-tocopherol and dietary MUFA/PUFA exists for microsome α-tocopherol concentration (α-tocopherol [log μg g^?1]=1.14 (±0.169) (P<0.0001)+0.0056 (±0.00099)·dietary α-tocopherol [mg kg^?1 diet] (P<0.0001)+0.54 (±0.206)·dietary MUFA/PUFA (P<0.0131)?0.0033 (±0.0011)·dietary α-tocopherol [mg kg^?1)]×dietary MUFA/PUFA (P<0.0067)), and hexanal concentration in meat (hexanal [ng·g^?1]=14807.9 (±1489.8)?28.8 (±10.6) dietary α-tocopherol [mg·kg^?1] (P<0.01)?8436.6 (±1701.6)·dietary MUFA/PUFA (P<0.001)+24.0 (±11.22)·dietary α-tocopherol·dietary MUFA/PUFA (P<0.0416)). It is concluded that partial substitution of dietary PUFA with MUFA lead to an increase in the concentration of α-tocopherol in muscle and microsome extracts. An interaction between dietary α-tocopherol and fatty acids exists, in which at low level of dietary vitamin E inclusion, a low MUFA/PUFA ratio leads to a reduction in the concentration of α-tocopherol in microsome extracts and a concentration of hexanal in meat above the expected values.     

1-Hydroxycyclopropane carboxylic acid phosphate: A potent inhibitor of enzymes metabolizing phosphoenolpyruvate

1-Hydroxycyclopropane carboxylic acid phosphate has been synthesized from diethyl succinate by acyloin condensation followed by ring contraction and phosphorylation. This compound is a potent competitive inhibitor of enzymes utilizing phosphoenolpyruvate. For phosphoenolpyruvate from maize, K_i = 7.3 μM at pH 8.0 in the presence of Mg²⁺. For pyruvate kinase, K_i = 2.0 mM at pH 7.0. For enolase, K_i = 8.0 μM at pH 8.0. In each case, this compound is a substantially better inhibitor than the commonly used phosphoenolpyruvate analogs phosphoglycolate and phospholactate, presumably because of the similarity in geometric and electronic structure between the cyclopropane compound and phosphoenolpyruvate.     

Quirks of dye nomenclature. 9. Fluorescein

Adolf Baeyer announced the discovery of fluorescein in 1871 and named it after its most striking property, i.e., fluorescence. I describe here the synthesis of fluorescein. There are seven molecular species in both the solid state or in solution. I also summarize some of the diverse applications of the dye, both medical and nonmedical, which depend mostly on the facile detection of fluorescein at low concentration. Both animal and human toxicity are examined.     

Quirks of dye nomenclature. 1. Evans blue

The history, origin, identity, chemistry and use of Evans blue dye are described along with the first application to staining by Herbert McLean Evans in 1914. In the 1930s, the dye was marketed under the name, Evans blue dye, which was profoundly more acceptable than the ponderous chemical name.     

Towards translational rodent models of depression

Rodent models of depression have been developed in an effort to identify novel antidepressant compounds and to further our understanding of the pathophysiology of depression. Various rodent models of depression and antidepressant-like behaviour are currently used but, clearly, none of these current models fully recapitulate all features of depression. Moreover, these models have not resulted in the development of novel non-monoaminergic-based antidepressants with clinical efficacy. Thus, a refinement of the current models of depression is required. The present review outlines the most commonly used models of depression and antidepressant drug-like activity and suggests several factors that should be considered when refining these models.     

Flow cytometric detection of lymphocyte alterations in Huntington's disease

Several recent reports indicate that patients with Huntington's Disease (HD) may manifest membrane abnormalities in a wide variety of cells including peripheral blood lymphocytes. In this study, flow cytometry is used in conjunction with the fluorescent membrane probe, 8-anilino-1-naphthalene sulfonate (ANS), to examine peripheral blood lymphocytes from 16 HD patients and 14 age- and diet-matched control subjects. Increased ANS fluorescence intensity of lymphocytes (p less than 0.02) was found in HD patients as compared to control subjects. These differences are masked when the mean fluorescence of the total leukocyte population is measured, possibly explaining conflicting data of other investigators. These observed differences in ANS fluorescence intensity between HD patients and control subjects support the concept of a gene defect which may be expressed as membrane alterations in non-neural as well as neural cells. The selective alterations of lymphocytes may also reflect altered immunological activity reported in HD.     

Cross-linkage of a receptor on nonspecific cytotoxic cells or treatment with calcium ionophore triggers increased phosphorylation of serine residues

Cross-linkage of a putative receptor protein on nonspecific cytotoxic cells (NCC) with monoclonal antibody (mab) 5C6 produces: activation of cytotoxicity; increased release of free cytosolic calcium; increased levels of IP3 and IP4; and increased DNA synthesis. Mab-binding also caused increased expression of various proto-oncogene kinases and increased expression of tyrosine phosphorylated proteins. In the present study NCC triggering by mab 5C6 was linked to serine specific kinase/phosphatase action. Concomitant with mab 5C6 activation, two proteins of 55-60 and 25-30 kDa were hyperphosphorylated on serine residues (15-30 min post-activation) determined by immunoprecipitation with an anti-phosphoserine specific mab. These proteins appeared to be components of a large macromolecular protein complex (> 170 kDa) determined by resolution in reducing and non-reducing SDS-PAGE. Sequential immunoprecipitation experiments revealed that these proteins were not PKC or p56^lck. Activation of NCC with the calcium ionophore A23187 caused the expression of this same complex of serine phosphorylated proteins. These data indicate that hyperphosphorylation of serine residues is associated with increased NCC cytotoxicity. Activation may be associated with receptor cross-linkage or calcium ionophore treatment, both events producing the phosphorylation of the same substrates.     

DEVELOPMENTAL INSTABILITY AND HIGH MERISTIC COUNTS IN INTERSPECIFIC HYBRIDS OF SALMONID FISHES

Interspecific hybrids have been proposed to have reduced developmental stability in comparison to their parental species because the parental genomes have not undergone selection for the maintenance of developmental stability when they occur together. We present data from four interspecific hybrids of salmonid fishes that support this view. Natural hybrids of bull trout (Salvelinus confluentus) with brook trout (Salvelinus fontinalis) and laboratory hybrids of rainbow trout (Salmo gairdneri) with Yellowstone (Salmo clarki bouvieri), westslope (S. c. lewisi), and coastal (S. c. clarki) cutthroat trout all have higher levels of fluctuating asymmetry than either of their parental species raised in the same environment. Thus, the hybrids have reduced developmental stability. The hybrids do not have meristic counts intermediate to the counts of the parental species. The hybrids usually have counts as high as the species with the higher count for those characters that differ between the parental species and often have higher counts for those characters that do not differ between the parental species. We suggest that the tendency for interspecific hybrids to have high meristic counts may be related to differences between the species in the length and timing of the developmental periods during which the counts of the characters are determined.     

ALS/FTD‐associated FUS activates GSK‐3β to disrupt the VAPB–PTPIP51 interaction and ER–mitochondria associations

Defective FUS metabolism is strongly associated with amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD), but the mechanisms linking FUS to disease are not properly understood. However, many of the functions disrupted in ALS/FTD are regulated by signalling between the endoplasmic reticulum (ER) and mitochondria. This signalling is facilitated by close physical associations between the two organelles that are mediated by binding of the integral ER protein VAPB to the outer mitochondrial membrane protein PTPIP51, which act as molecular scaffolds to tether the two organelles. Here, we show that FUS disrupts the VAPB–PTPIP51 interaction and ER–mitochondria associations. These disruptions are accompanied by perturbation of Ca²⁺ uptake by mitochondria following its release from ER stores, which is a physiological read‐out of ER–mitochondria contacts. We also demonstrate that mitochondrial ATP production is impaired in FUS‐expressing cells; mitochondrial ATP production is linked to Ca²⁺ levels. Finally, we demonstrate that the FUS‐induced reductions to ER–mitochondria associations and are linked to activation of glycogen synthase kinase‐3β (GSK‐3β), a kinase already strongly associated with ALS/FTD.     

Holocene reef evolution in a macrotidal setting: Buccaneer Archipelago,Kimberley Bioregion,Northwest Australia

This study uses information derived from cores to describe the Holocene accretion history of coral reefs in the macrotidal (up to 11 m tidal range) Buccaneer Archipelago of the southern Kimberley coast, Western Australia. The internal architecture of all cored reefs is broadly similar, constituting well-preserved detrital coral fragments, predominantly branching Acropora, in a poorly sorted sandy mud matrix. However, once the reefs reach sea level, they diverge into two types: low intertidal reefs that maintain their detrital character and develop relatively narrow, horizontal or gently sloping reef flats at approximately mean low water spring, and high intertidal reefs that develop broad coralline algal-dominated reef flats at elevations between mean low water neap and mean high water neap. The high intertidal reefs develop where strong, ebb-dominated, tidal asymmetry retains seawater over the low tide and allows continued accretion. Both reef types are ultimately constrained by sea level but differ in elevation by 3–4 m.