Computational modelling of the binding of arachidonic acid to the human monooxygenase CYP2J2.

An experimentally determined structure for human CYP2J2-a member of the cytochrome P450 family with significant and diverse roles across a number of tissues-does not yet exist. Our understanding of how CYP2J2 accommodates its cognate substrates and how it might be inhibited by other ligands thus relies on our ability to computationally predict such interactions using modelling techniques. In this study we present a computational investigation of the binding of arachidonic acid (AA) to CYP2J2 using homology modelling, induced fit docking (IFD) and molecular dynamics (MD) simulations. Our study reveals a catalytically competent binding mode for AA that is distinct from a recently published study that followed a different computational pipeline. Our proposed binding mode for AA is supported by crystal structures of complexes of related enzymes to inhibitors, and evolutionary conservation of a residue whose role appears essential for placing AA in the right site for catalysis. Graphical Abstract Arachidonic acid docked in the active site of CYP2J2 assumes a catalytically competent binding mode stabilised by hydrogen bonds to Arg117.

Analysis of dystroglycan regulation and functions in mouse mammary epithelial cells and implications for mammary tumorigenesis.

Abnormalities in the interactions of cells with the extracellular matrix (ECM) play an important role in the development and progression of many types of cancer and are a hallmark of malignant transformation. The dystroglycan (DG) complex is a transmembrane glycoprotein that forms a continuous link from the ECM to the actin cytoskeleton, providing structural integrity and perhaps transducing signal, in a manner similar to integrins. Deregulated expression of DG has been reported in a variety of human malignancies and related to tumor differentiation and aggressiveness. In breast cancer, reduced DG expression has been associated with patient survival and with loss of differentiation of tumor cells. Limited data are available on DG physiology in epithelial cells. In this study, we used the HC11 spontaneously immortalized murine mammary epithelial cells to study DG function(s) and regulation in normal cells. We found that expression of DG protein and mRNA is cell-cycle and cell-density regulated in these cells. Moreover, expression of both DG subunits increased upon lactogenic differentiation of the HC11 cells. The turnover of cell-surface-expressed DG was evaluated in the same cells and half-life of DG subunits was evaluated to be about 12 h. DG-specific small inhibitory RNAs were used to analyze the effects of a reduced expression of DG in these cells. Cells in which DG expression was suppressed were growth inhibited, accumulated in the S-phase of the cell cycle, failed to undergo lactogenic differentiation, and displayed an increase in the percentage of apoptotic cells. Moreover, changes were observed in the expression and/or activity of several molecules involved in cell growth control. These results demonstrate that DG expression is tightly regulated in normal mammary epithelial cells and support the hypothesis that DG is involved in several functions other than structural integrity in these cells. This finding provides new insight into the roles played by DG in epithelial cell physiology and will contribute to our understanding of its involvement in the process of epithelial cell transformation.

Increased accuracy of biopsy Gleason score obtained by extended needle biopsy.

PURPOSE: Accurate tumor grading is critical for adequate prostate cancer treatment. Nonetheless, the Gleason score of standard sextant biopsy correctly predicts the Gleason score of the radical prostatectomy specimen in about 50% of cases. We investigated if extended needle biopsy could improve biopsy Gleason score accuracy. MATERIALS AND METHODS: Laparoscopic transperitoneal radical prostatectomy was performed in 135 patients. Prostate cancer was diagnosed in 89 cases by standard sextant transrectal (6 to 8 cores) biopsy and in 46 by extended needle (12 core transperineal under transrectal guidance) biopsy. Preoperative evaluation included digital rectal examination, prostatic specific antigen measurement, transrectal ultrasonography and endorectal coil magnetic resonance imaging in all patients. All biopsy and prostatectomy specimens were reviewed by a single pathologist. RESULTS: Clinical characteristics were similar in the 2 groups. The concordance between prostate biopsy and radical prostatectomy Gleason score was 32 of 46 cases (70%) and 44 of 89 (49%) for 12 core and standard transrectal biopsy, respectively (z test p = 0.0127). Biopsy under grading was found in 11 of 46 cases (24%) and 35 of 89 (39%) (z test p = 0.0366), and biopsy over grading was found in 3 of 46 (6%) and 10 of 89 (11%) (z test p = 0.1894) with 12 core and standard transrectal biopsy, respectively. Primary Gleason pattern was predicted exactly by biopsy in 40 of 46 cases (87%) and 56 of 89 (63%) with 12 core and standard sextant biopsy, respectively (z test p = 0.0018). CONCLUSIONS: Extended needle biopsy significantly increases the accuracy of biopsy Gleason score for assessing final prostate cancer grade.

A man with worsening weakness.

The contemporary presence of organomegaly, skin manifestations, polyneuropathy, endocrinopathy and monoclonal component characterises the POEMS syndrome, often associated with osteosclerotic myeloma and Castelman's disease and more frequent in the Japanese. Clinical manifestations seem to be related to the production of many interleukins, mainly IL-1, IL-6 and TNF. Several endocrinopathies have been described, the most frequent being diabetes. Only one previous case of hypoparathyroidism associated with the syndrome has been described in medical reviews. Polyneuropathy is often sensitivo-motory and skin disease accounts for Raynaud phenomenon, skin pigmentation, hypertricosis and others. We describe the case of a 74-year-old man who underwent clinical examination for weakness mainly in the legs. Clinical and instrumental data showed rhabdomyolysis due to hypoparathyroidism. The contemporary presence of a monoclonal band of light chains on proteic electrophoresis, organomegaly and distal leg neuropathy allowed us to make a diagnosis of POEMS syndrome.

Constituents of essential oil of Commiphora guidotti.

From the essential oil of Commiphora guidotti seven sesquiterpene hydrocarbons and a furanosesquiterpenoid, furanodiene, were isolated.

The effect of some flavolignans on lipid synthesis in ethanol-intoxicated hepatocytes in primary culture.

Rat liver cells in primary culture have been used to investigate the effect of ethanol and of two flavolignans 3,7-dihydroxy-2-(1,4-benzodioxan-6-yl)chroman-4-one (I) and 3,7-dihydroxy-2-[(2,3-diphenyl)-1,4-benzodioxan-6-yl]chroman-4-one (II) on the incorporation of [2-3H]-glycerol into lipids. Ethanol produces a decrease of the incorporation of labelled glycerol into lipids, whereas at the longest times of incubation flavolignans have an opposite effect. Neutral lipid/phospholipid labelling ratio is modified by ethanol in favour of neutral lipids. This action is counteracted by both flavolignans, which are therefore able to hinder, at least partially, the actions of ethyl alcohol on liver lipid metabolism.

[A little known source of lead poisoning: rasp and file manufacture (author's transl)]. / Una fonte poco conosciuta di saturnismo: la produzione artigianale di raspe e lime

Seventy-two subjects employed in rasp manufacturing and, especially, manual "engraving" were studied by the authors, mainly in order to find out whether lead poisoning could be induced by their particular working activity. Twelve subjects (16.7%) were found to have standard biological parameters for lead (blood lead, urinary delta-ALA and urinary coproporphyin levels) within normal limits. Twenty-five (34.7%) showed hematochemical and urinary signs of increased lead absorption, and 35 (48.6%) marks of lead poisoning, more or less severe. The manufacturing process was then studied and working places were inspected too. Finally, lead poisoning was found to be due to a small lead block, used by hand-engravers in order to avoid damages to the already engraved surfaces of the rasps. This survey leads therefore to the conclusion that rasp manual engraving has to be included among the working activities which can induce lead poisoning.