Effects of Various Polyunsaturated Fatty Acids on Blood Cholesterol and Eicosanoids in Rats

The hypocholesterolemic efficacy of various polyunsaturated fatty acids was compared in rats given cholesterol-enriched diets with (0.004%) or without indomethacin, the cyclooxygenase inhibitor. Evening primrose oil (EPO, linoleic+ γ-linolenic), safflower oil (SFO, linoleic) or soybean oil (SBO, linoleic + α-linolenic) were added to diets at the 10% level. The serum cholesterol level of the EPO group was consistently lower than the other groups and after 3 weeks, it was significantly different from the SFO group without indomethacin and the SBO group with indomethacin. In rats fed EPO, the aorta tended to produce more prostacyclin whereas the concentration of plasma thromboxane B₂ was much lower than in rats fed SFO or SBO. The effects of indomethacin on these eicosanoids were less evident in rats fed EPO. Thus, in addition to the hypocholesterolemic action of β-linolenic acid (GLA) in preference to linoleic and possibly α-linolenic acid, GLA appears to cultivate an environment suitable for the prevention of carbiovascular disease even in the presence of excess cholesterol in the diet.     

Purification and Properties of Alcohol Dehydrogenase from Tea Seeds

The process of antigen presentation is not well understood. We screened for drugs that distinguish presentation of allogeneic class 2 antigens and exogenous antigens. When spleen cells were used as antigen presenting cells (APC), leupeptin and antipain preferentially inhibited allogeneic class 2 presentation, while they did not affect presentation of exogenous antigen and T cell growth. In contrast, they inhibited both presentations when spleen adherent cells (SAC) were used as APC. Our results suggest that SAC (mainly macrophages) and splenic B cells use different pathways to present exogenous antigens and that pathways to present allogeneic class 2 molecules are similar.     

Isolation of Z-3-Hexenal in Tea Leaves,Thea sinensis,and Synthesis Thereof

Z-3-Hexenal, a precursor in the biosynthesis of leaf alcohol and leaf aldehyde, was first isolated from fresh tea leaves, Thea sinensis and its structure was confirmed by unequivocal synthetic evidence.     

Diarylheptanoids with inhibitory effects on melanogenesis from the rhizomes of Curcuma comosa in B16 melanoma cells

The methanolic extract from the dried rhizomes of Curcuma comosa cultivated in Thailand was found to inhibit melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the methanolic extract, three new diarylheptanoids, diarylcomosols I–III, were isolated together with 12 known diarylheptanoids. Their chemical structures were elucidated on the basis of chemical and physicochemical evidence. The diarylheptanoids inhibited melanogenesis, and several structural requirements of the active constituents for the inhibition were clarified. In particular, (3R)-1,7-bis(4-hydroxyphenyl)-(6E)-6-hepten-3-ol exhibited stronger inhibitory effect [IC₅₀ = 0.36 μM] without inducing cytotoxicity. The biological effect was much stronger than that of a reference compound, arbutin [IC₅₀ = 174 μM]. We conclude that diarylheptanoid analogs are promising therapeutic agents for the treatment of skin disorders.     

An abundant LEA protein in the anhydrobiotic midge,PvLEA4, acts as a molecular shield by limiting growth of aggregating protein particles

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Cell selective targeting of a simian virus 40 virus-like particle conjugated to epidermal growth factor

Simian virus 40 (SV40) virus-like particles (VLPs) are efficient nanocarriers for gene delivery. VLPs conjugated to human epidermal growth factor (hEGF) were prepared and the cell selectivity of the VLP was examined using human epithelial carcinoma A431 cells, which overexpress the EGF receptor. The endocytic efficiency was determined by the level of Gaussia luciferase activity from the encapsulated protein in hEGF-conjugated VLPs. EGF receptor-mediated endocytosis of hEGF-conjugated VLPs was significantly increased and was confirmed by fluorescence imaging using mCherry encapsulated in hEGF-conjugated VLPs. These results suggest that VLPs of SV40 conjugated to a specific ligand could be used for cell selective gene delivery.     

A useful immunohistochemical approach to evaluate intraductal proliferative lesions of the breast and to predict their prognosis

An examination was performed on 16 intraductal proliferative breast lesions diagnosed as intraductal papillomas (IP) or usual ductal hyperplasia (UDH), which were followed up for more than 3 years. An immunohistochemical marker panel combining myoepithelial markers, high-molecular-weight keratin (HMWK) and neuroendocrine markers was used. Two of 11 IP cases were re-evaluated as atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS). These cases developed breast cancer after the first operation. One IP case showed repeated recurrences. None of the other IP and UDH cases had breast cancer or recurrence. The ADH, DCIS and the recurrent IP showing a solid growth lacked myoepithelia, but the recurrent IP expressed HMWK, immunohistochemically. Interestingly, these three lesions were weakly positive for neuroendocrine markers. All other IPs and UDHs, including lesions having solid components, were negative for neuroendocrine markers, and most of them were positive for myoepithelial markers and/or HMWK. A combination of the above immunohistochemical markers seems useful to evaluate intraductal proliferative lesions and to predict their prognosis. In particular, intraductal proliferative lesions with solid components exhibiting positivity for neuroendocrine markers should be followed up carefully to monitor breast cancer risk or recurrence.     

Enzymatic synthesis of capsaicin 4-O-β-xylooligosaccharides by β-xylosidase from Aspergillus sp

Capsaicin 4-O-β-xylooligosaccharides were synthesized by a biocatalytic xylosylation using Aspergillus sp. β-xylosidase. Capsaicin was converted into three new capsaicin glycosides, i.e. capsaicin 4-O-β-xyloside, capsaicin 4-O-β-xylobioside, and capsaicin 4-O-β-xylotrioside in 15, 12 and 10% yield, respectively. All products were isolated from the reaction mixtures by preparative HPLC. The structures of the products were determined by NMR spectroscopic method.     

Ect2, an Ortholog of <Emphasis Type="Italic">Drosophila’s</Emphasis><Emphasis Type="Italic">Pebble</Emphasis>, Negatively Regulates Neurite Outgrowth in Neuroblastoma × Glioma Hybrid NG108-15 Cells

To identify genes required for brain development, we previously performed in vivo RNA interference (RNAi) screening in Drosophila embryos. We identified pebble as a gene that disrupts development of the Drosophila nervous system. Although pebble has been shown to be involved in neuronal development of Drosophila in several screens, the involvement of Ect2, a mammalian ortholog of pebble, in mammalian neuronal development has not been addressed. To examine the role of Ect2 in neuronal differentiation, we performed Ect2 RNAi in the mouse neuroblastoma × rat glioma NG108-15 cell line. Depletion of Ect2 resulted in an increased proportion of binucleate cells and morphological differentiation of NG108-15 cells characterized by the outgrowth of neurites. These morphological changes were correlated with an increased level of acetylcholine esterase mRNA. In addition, expression of Ect2 was decreased in differentiated NG108-15 cells induced by dibutyryl cyclic AMP. These findings indicate that Ect2 negatively regulates the differentiation of NG108-15 cells and suggest that Ect2 may play a role in neuronal differentiation and brain development in vivo.