6-Ethyl-5-hydroxy-2,7-dimethoxy-1,4-naphthoquinone from Hendersonula toruloidea: A biosynthetic study using C labels detected by nuclear magnetic resonance and C tracers

Production of 6-ethyl-5-hydroxy-2,7-dimethoxy-1,4-naphthoquinone was obtained by growth of Hendersonula toruloidea on Czapek-Dox broth supplemented with malt extract. Stationary cultures were grown at 28°C for 21–22 days yielding about 6 mg of metabolite per 700 ml of culture fluid. The best incorporations of isotopic tracers were obtained by addition at the 20th day of growth, followed by harvest 24–48 hr later. With [2-¹⁴C]acetate, incorporation values were in the range of 0.1–0.3% with dilution values from 2000 to 5900. With [1-¹⁴C]propionate, incorporations were much lower (0.04%) and dilutions much higher (120,000). Activity from [¹⁴CH₃]methionine was incorporated only into the OCH₃ groups (incorporation values, 0.5–0.7%). Nuclear magnetic resonance studies confirmed that propionate was not a precursor. Using [1,2-¹³C]acetate, substantial enrichments were obtained at all carbon atoms except those of the OCH₃ groups. The following pairs of carbon atoms were shown to be derived from acetate units: C-1 + 2, C-3 + 4, C-5 + 10, C-6 + 7, C-8 + 9, C-11 + 12. The biosynthetic pathway is clearly that of acetate plus polymalonate. Experiments with [2-¹³C²H₃]acetate suggested that the “starter” acetate unit was located at positions C-12 + 11.     

6-Ethyl-5-hydroxy-2,7-dimethoxy-1,4-naphthoquinone from Hendersonula toruloidea: A biosynthetic study using 13C labels detected by nuclear magnetic resonance and 14C tracers

Production of 6-ethyl-5-hydroxy-2,7-dimethoxy-1,4-naphthoquinone was obtained by growth of Hendersonula toruloidea on Czapek-Dox broth supplemented with malt extract. Stationary cultures were grown at 28°C for 21–22 days yielding about 6 mg of metabolite per 700 ml of culture fluid. The best incorporations of isotopic tracers were obtained by addition at the 20th day of growth, followed by harvest 24–48 hr later. With [2-¹⁴C]acetate, incorporation values were in the range of 0.1–0.3% with dilution values from 2000 to 5900. With [1-¹⁴C]propionate, incorporations were much lower (0.04%) and dilutions much higher (120,000). Activity from [${}^{14}\text{CH}{}_3$]methionine was incorporated only into the OCH₃ groups (incorporation values, 0.5–0.7%). Nuclear magnetic resonance studies confirmed that propionate was not a precursor. Using [1,2-¹³C]acetate, substantial enrichments were obtained at all carbon atoms except those of the OCH₃ groups. The following pairs of carbon atoms were shown to be derived from acetate units: C-1 + 2, C-3 + 4, C-5 + 10, C-6 + 7, C-8 + 9, C-11 + 12. The biosynthetic pathway is clearly that of acetate plus polymalonate. Experiments with [2-¹³C²H₃]acetate suggested that the “starter” acetate unit was located at positions C-12 + 11.     

Correlates of pentraxin 3 serum concentration in men and women with type 2 diabetes

Elevated levels of plasma pentraxin 3 (PTX3), a marker of inflammation, are associated with the risk of developing cardiovascular diseases in the general population, as well as in patients with type 2 diabetes (DM2). In this study, we aimed to determine factors associated with PTX3 serum concentrations in men and women with DM2. The study included 116 consecutive patients (67 men and 49 women) with DM2 from an outpatient diabetic clinic. Men were characterised by lower age and higher uric acid, creatinine and bilirubin concentrations and waist/hip ratio than women. In women, low-density lipoprotein cholesterol (LDL-C) levels were higher than in men. In men, median (interquartile range) values of PTX3 concentration were 4.02 (1.99), and in women they were 4.53 (3.31) ng/ml (NS). In men, PTX3 concentrations correlated with total cholesterol (TC), triglycerides, apolipoprotein (Apo) C3, Apo B48, Glc and creatinine levels. In women, PTX3 correlated significantly with TC and LDL-C and Apo B100. Partial regression analysis revealed that after adjusting for age, PTX3 concentrations in men were significantly associated with TC, LDL-C, triglycerides, creatinine, Apo C3 and Apo B48, while in women they were associated with TC, LDL-C and Apo B100. The results could be of importance in sex-specific prevention of vascular complications in DM2 patients.     

Molecular Architecture of Plant Thylakoids under Physiological and Light Stress Conditions: A Study of Lipid–Light-Harvesting Complex II Model Membranes

In this study, we analyzed multibilayer lipid-protein membranes composed of the photosynthetic light-harvesting complex II (LHCII; isolated from spinach [Spinacia oleracea]) and the plant lipids monogalcatosyldiacylglycerol and digalactosyldiacylglycerol. Two types of pigment-protein complexes were analyzed: those isolated from dark-adapted leaves (LHCII) and those from leaves preilluminated with high-intensity light (LHCII-HL). The LHCII-HL complexes were found to be partially phosphorylated and contained zeaxanthin. The results of the x-ray diffraction, infrared imaging microscopy, confocal laser scanning microscopy, and transmission electron microscopy revealed that lipid-LHCII membranes assemble into planar multibilayers, in contrast with the lipid-LHCII-HL membranes, which form less ordered structures. In both systems, the protein formed supramolecular structures. In the case of LHCII-HL, these structures spanned the multibilayer membranes and were perpendicular to the membrane plane, whereas in LHCII, the structures were lamellar and within the plane of the membranes. Lamellar aggregates of LHCII-HL have been shown, by fluorescence lifetime imaging microscopy, to be particularly active in excitation energy quenching. Both types of structures were stabilized by intermolecular hydrogen bonds. We conclude that the formation of trans-layer, rivet-like structures of LHCII is an important determinant underlying the spontaneous formation and stabilization of the thylakoid grana structures, since the lamellar aggregates are well suited to dissipate excess energy upon overexcitation.     

A Supposed Eupelycosaur Body Impression from the Early Permian of the Intra-Sudetic Basin,Poland

We describe a new specimen of a supposed Paleozoic tetrapod body impression from the Lower Permian S?upiec Formation in the Intra-Sudetic Basin, Poland. The size, integument morphology of belly and part of tail imprints, and the morphology of a well-preserved pes track diagnose the specimen and readily distinguish it from other described specimens of body impressions of Paleozoic tetrapods. The eupelycosaur identity of this new specimen is based on the identification of the footprint Dimetropus leisnerianus (Geinitz, 1863 Geinitz, H. B. 1863. Beiträge zur Kenntnis der organischen Überreste in der Dyas (oder permischen Formation zum Theil) und über den Namen Dyas. Neues Jahrbuch für Mineralogie, Geologie und Paläontologie, : 385–398.  [Google Scholar]), which is connected with the inferred body imprint. The morphology of integument impressions indicates the presence of the various-sized square or rectangular-shaped scales on the bottom part of the belly and tail of this eupelycosaurid trackmaker.     

Predictive Factors of Late Venous Aortocoronary Graft Failure: Ultrastructural Studies

Background

Venous aortocoronary graft arterialization may precede a preterm occlusion in some coronary artery bypass grafting (CABG) patients. The aim of the present study was to identify ultrastructural variations in the saphenous vein wall that may have an impact on the development of venous graft disease in CABG patients.

Methods

The study involved 365 consecutive patients with a mean age of 62.9±9.4 years who underwent isolated CABG. The thickness and area of the whole venous wall, the tunica intima, the tunica media and the adventitia and the number and shape (length, thickness and length/thickness ratio) of the nuclei in the medial smooth muscle cells nuclei in the distal saphenous vein segments were evaluated by ultrastructural studies. Patients were followed up for 41 to 50 months (mean 45.1±5.1). Saphenous vein graft patency was assessed by follow-up coronary angiography. Logistic regression models were used to identify independent risk factors for late graft failure.

Results

In 71 patients significant lesions in the saphenous vein grafts were observed. The whole venous wall thickness (437.5 µm vs. 405.5 µm), tunica media thickness (257.2 µm vs. 211.5 µm), whole venous wall area (2.23 mm² vs. 2.02 mm²) and tunica media area (1.09 mm² vs. 0.93 mm²) were significantly larger for this group of patients than for those without graft disease. In the latter group more elongated smooth muscle cell nuclei (higher length/thickness ratio) were found in the tunica media of the saphenous vein segments. Thickening of the saphenous vein tunica media and chunky smooth muscle cell nuclei were identified as independent risk factors for graft disease development.

Conclusions

Saphenous vein tunica media hypertrophy (resulting in wall thickening) and chunky smooth muscle cell nuclei might predict the development of venous graft disease.     

Ecological Network Indicators of Ecosystem Status and Change in the Baltic Sea

Several marine ecosystems under anthropogenic pressure have experienced shifts from one ecological state to another. In the central Baltic Sea, the regime shift of the 1980s has been associated with food-web reorganization and redirection of energy flow pathways. These long-term dynamics from 1974 to 2006 have been simulated here using a food-web model forced by climate and fishing. Ecological network analysis was performed to calculate indices of ecosystem change. The model replicated the regime shift. The analyses of indicators suggested that the system’s resilience was higher prior to 1988 and lower thereafter. The ecosystem topology also changed from a web-like structure to a linearized food-web.     

Galactosylceramide Affects Tumorigenic and Metastatic Properties of Breast Cancer Cells as an Anti-Apoptotic Molecule

It was recently proposed that UDP-galactose:ceramide galactosyltransferase (UGT8), enzyme responsible for synthesis of galactosylceramide (GalCer), is a significant index of tumor aggressiveness and a potential marker for the prognostic evaluation of lung metastases in breast cancer. To further reveal the role of UGT8 and GalCer in breast cancer progression, tumorigenicity and metastatic potential of control MDA-MB-231 cells (MDA/LUC) and MDA-MB-231 cells (MDA/LUC-shUGT8) with highly decreased expression of UGT8 and GalCer after stable expression of shRNA directed against UGT8 mRNA was studied in vivo in athymic nu/nu mice. Control MDA/LUC cells formed tumors and metastatic colonies much more efficiently in comparison to MDA/LUC-shUGT8 cells with suppressed synthesis of GalCer after their, respectively, orthotopic and intracardiac transplantation. These findings indicate that UGT8 and GalCer have a profound effect on tumorigenic and metastatic properties of breast cancer cells. In accordance with this finding, immunohistochemical staining of tumor specimens revealed that high expression of UGT8 accompanied by accumulation of GalCer in MDA-MB-231 cells is associated with a much higher proliferative index and a lower number of apoptotic cells in comparison to the MDA/LUC-shUGT8 cells. In addition, it was found that expression of UGT8 in MDA-MB-231 cells increased their resistance to apoptosis induced by doxorubicin in vitro. Therefore, these data suggest that accumulation of GalCer in tumor cells inhibits apoptosis, which would facilitates metastatic cells to survive in the hostile microenvironment of tumor in target organ.