Heme is a positive regulator of cytochrome P-450 gene transcription

Inhibitors of heme biosynthesis such as CoCl2, 3-amino-1,2,4-triazole, and thioacetamide block the 3-methylcholanthrene-mediated induction of cytochrome P-450 (c + d) messenger RNAs and their transcription in rat liver. This effect is specific, since the messenger RNA levels for albumin and glutathione transferase (Ya + Yc) and their transcription are not significantly influenced under conditions of heme depletion. Exogenous administration of heme at very low doses (50 μg/100 g body wt) is able to completely counteract the effects of the heme biosynthetic inhibitors on cytochrome P-450 (c + d) messenger RNA levels and their transcription. This constitutes a direct proof for the role of heme as a positive regulator of cytochrome P-450 gene transcription.

Heme regulates cytochrome P-450 gene transcription elongation

Administration of 3-methylcholanthrene (MC) to rats results in a striking increase in the transcription of cytochrome P-450 (c+d) messenger RNA with isolated nuclei, which is blocked by the simultaneous administration of cobalt chloride, an inhibitor of heme biosynthesis. Transcription of cytochrome P-450 (c+d) mRNAs with nuclei isolated from MC treated rats shows a linear increase with time of incubation, whereas it shows a progressive decrease with incubation time in the case of nuclei isolated from MC+CoCl2 treated rats. Addition of heme in vitro (10−6M) to the latter nuclei results in a significant counteraction of the decreased cytochrome P-450 (c+d) mRNA transcription. The inhibition in transcription rates observed in MC+CoCl2 treated rat liver nuclei is more pronounced with the seventh exon probe than with the second exon probe. Once again, in vitro heme addition can counteract the inhibition observed with both the probes. Since run off transcription with isolated nuclei represents essentially elongation of the initiated transcripts, the data obtained can be interpreted on the basis that heme regulates cytochrome P-450 gene transcription elongation.

Vapor phase oxidation of p-xylene

The kinetics of the vapor phase oxidation of p-xylene over ferric molybdate catalyst were studied in an isothermal, differential, tubular flow reactor in the temperature range of 360 to 420° C. The major product obtained was p-tolualdehyde with small amounts of maleic anhydride and p-toluic acid. No terephthalic acid or CO2 were observed. The reaction rate data collected fit the redox model given by Equation 1. The values of activation energies Ex, Eo and frequency factors Ax, Ao obtained are 72, 63 kJ/mol and 0.64, 2.89 m3/kg catalyst s respectively. The reaction mechanism was established by studying the oxidation of p-tolualdehyde, toluic and terephthalic acids. It is concluded that the reaction follows a parallel-consecutive scheme. On a étudié la cinétique de l'oxydation, en phase gazeuse, du para-xylène sur un catalyseur consistant en molybdate ferrique; cette oxydation s'est faite dans un réacteur à écoulement tubulaire, isothermique et différentiel, dans une échelle de températures comprises entre 360°C et 420°C. Le produit principal obtenu a été le para-tolualdéhyde; on a aussi trouvé de faibles quantités d'anhydride maléique et d'acide para-toluique, mais on n'a pas noté la présence d'acide téréphtalique ni d'anhydride carbonique (CO2). Les résultats obtenus en ce qui a trait à la vitesse de réaction concordent bien avec les données du modèle redox indiquées par l'équation 1. Les valeurs des énergies d'activation Ex et Eo ainsi que des facteurs de fréquence Ax et Ao obtenus sont respectivement 72 et 63 kilojoules/mol. et 0.64 × 103 et 2.89 m3/kg de catalyseur. On a établi le mécanisme de la réaction en étudiant l'oxydation du para-tolualdéhyde et des acides toluique et téréphtalique. On conclut que la réaction se fait d'une manière parallèle et consécutive.

Site of synthesis of cytochrome P-450 in liver

The suggestion that a rapidly sedimenting rough endoplasmic reticulum fraction in close association with mitochondria, is the preferred site of cytochrome P-450 synthesis has been examined. The rate of cytochrome P-450 synthesis in the different subcellular fractions has been evaluated Image , using the immunoprecipitation technique. The results indicate that the conventional microsomal fraction (100,000 X g sediment) is the major site of cytochrome P-450 synthesis and that the rapidly sedimenting rough endoplasmic reticulum fraction associated with mitochondria is not a preferred site for the hemoprotein synthesis.

Variation i kvinnors namnfraser i officiella dokument i Helsingfors 1780-1930 : Socioonomastiska synvinklar på makt och identitet

This dissertation is an onomastic study of variation in women s name phrases in official documents in Finland during the period 1780−1930. The aim is to discuss from a socio-onomastic perspective both the changeover from patronymics to inherited family names and the use of surnames after marriage (i.e. whether women adopted their husbands family names or retained their maiden names), before new laws in this area entered into force in Finland in the early 20th century. In 1920, a law on family names that required fixed names put an end to the use of the patronymic as a person s only surname. After 1929, it was no longer possible for a married woman to retain her maiden name. Methodologically, to explain this development from a socio-onomastic perspective, I have based my study on a syntactic-semantic analysis of the actual name phrases. To be able to demonstrate the extensive material, I have elaborated a scheme to divide the 115 different types of name phrases into 13 main categories. The analysis of the material for Helsinki is based on frequency calculations of the different types of name phrases every thirtieth year, as well as on describing variation in the structure and semantic content of the name phrases, e.g. social variation in the use of titles and epithets. In addition to this, by applying a biographic-genealogical method, I have conducted two case studies of the usage of women s name phrases in the two chosen families. The study is based on parish registers from the period 1780−1929, estate inventory documents from the period 1780−1928, registration forms for liberty of trade from the period 1880−1908, family announcements on newspapers from the period 1829−1888, gravestones from the period 1796−1929 and diaries from the periods 1799−1801 and 1818−1820 providing a corpus of 5 950 name phrases. The syntactic-semantic analysis has revealed the overall picture of various ways of denoting women in official documents. In Helsinki, towards the end of the 19th century, the use of inherited family names seems to be almost fully developed in official contexts. At the late 19th century, a patronymic still appears as the only surname of some working-class women whereas in the early 20th century patronymics were only entered in the parish register as a kind of middle name. In the beginning of the 19th century, most married women were still registered under their maiden names, with a few exceptions among the bourgeoisie and upper class. The comparative analysis of name phrases in diaries, however, indicates that the use of the husband s family name by married women was a much earlier phenomenon in private contexts than in official documents. Keywords: socio-onomastics, syntactic-semantic analysis, name phrase, patronymic, maiden name, husband s family name