Aromatization of androstenedione by normal and neoplastic endometrium of the uterus

The ability of human uterine endometrium to aromatize androstenedione to estrogens was investigated using 10 normal and neoplastic tissues. Normal and neoplastic endometrial homogenates were incubated with [6,7-3H]androstenedione (A) and NADPH. Estrone (E1) and estradiol (E2) were subsequently isolated in amounts ranging from 0-17600 fmol/h/g and 0-377 fmol/h/g, respectively, from the incubates after purifications by using Bio-Rad AG1-X2 column, thin layer chromatographies and co-crystallization. The conversion of A to E1 and E2 was significantly higher in neoplastic tissues.     

The Association of Ascorbate and Ascorbate Oxidase in the Apoplast with IAA-Enhanced Elongation of Epicotyls from Vigna angularis

The level of (ascorbic acid (AA) plus dehydroascorbic acid (DHA))and the ratio of the level of AA to that of AA plus DHA in intercellularwashing fluid (IWF) of epicotyl segments from Vigna angularisdecreased from 2.8±0.3 to 1.2±0.5nmol (g fr wt)^–1and from 0.23±0.03 to 0.13±0.01, respectively,after incubation of the segments without IAA for 20 h at 27°C.However, these values changed to 5.3±1.7 nmol (g fr wt)^–1and 0.07±0.05 after incubation with 0.1 mM IAA. The activityof cell wall-bound ascorbate oxidase increased by about 20%and 70% after incubation without IAA and with IAA, respectively.However, the activity of cell wall-bound peroxidase was notaffected by incubation with or without IAA. The activities ofascorbate oxidase and peroxidase in IWF decreased by about 85and 75% after incubation without IAA. IAA did not affect thesedecreases to any great extent. A lignin-like compound was formedduring the incubation of epicotyl segments in the absence ofIAA. Formation of this compound was inhibited by IAA. The resultssuggest that one of the causes of the enhancement of elongationgrowth by IAA is the inhibition of peroxidase-dependent lignificationas a result of increases in levels of AA and DHA and in ascorbateoxidase activity. (Received August 16, 1993; Accepted December 6, 1993)     

Import and processing of the precursor of cytochrome P-450(SCC) by bovine adrenal cortex mitochondria

Isolated bovine adrenal cortex mitochondria imported in vitro synthesized pre-P-450(SCC) and processed it to the mature form. Partial radio-sequencing of the processed P-450(SCC) gave a result identical with that for authentic P-450(SCC). Rat liver mitochondria also imported pre-P-450(SCC) and processed it to the mature form, whereas bovine heart mitochondria were unable to import and process pre-P-450(SCC) although both mitochondrial preparations imported and processed pre-adrenodoxin. The pre-P-450(SCC) processing activity of bovine adrenal cortex mitochondria was associated with the matrix side surface of the inner membrane. The processing protease could be solubilized by sodium cholate and partially purified by ammonium sulfate fractionation. The partially purified processing protease cleaved pre-P-450(SCC) at the correct position. It was also active in processing pre-P-450(11 beta) but inactive toward pre-adrenodoxin. Bovine heart mitochondria lacked the processing activity to pre-P-450(SCC). The localization of pre-P-450(SCC) and mature P-450(SCC) in bovine adrenal cortex mitochondria was examined. Mature P-450(SCC) processed by the mitochondria was found associated with the matrix-side surface of the inner membrane, which is the correct location of P-450(SCC) in the cell. In the presence of o-phenanthroline, pre-P-450(SCC) was imported into the organelles without being processed and remained soluble in the matrix. The incorporation of newly processed mature P-450(SCC) into the inner membrane was also observed when pre-P-450(SCC) was incubated with inner membrane vesicles. Mature P-450(SCC) generated in vitro from pre-P-450(SCC) by the partially purified processing protease was incorporated not only into the inner membrane vesicles but also into bovine adrenal cortex microsomes. These findings suggested that the processing of pre-P-450(SCC) occurred prior to the incorporation of mature-P-450(SCC) into the inner membrane.     

Sequential polymerization of flagellin A and flagellin B into Caulobacter flagella

The mode of polymerization of two species of flagellins, flagellin A and flagellin B, in polar flagella of Caulobacter crescentus was examined. By immunological staining we found that 1 to 1.2 μm of the portion of the flagellar filament proximal to the cell was composed of flagellin B, whereas about 5 μm of the distal portion was composed of flagellin A. This result, together with the previous observation that a flagellin B-less mutant cannot form normal flagella but instead forms stubs in spite of their high level of flagellin A synthesis, indicates that flagellin B is very important for the formation of complete flagella and/or for the initiation of filament formation from the hook.     

Synthesis of cytochrome c oxidase in the liver of Rana catesbeiana tadpole treated with griseofulvin

The effect of griseofulvin treatment on the synthesis of cytochrome c oxidase was studied with the liver of the tadpole, Rana catesbeiana. (1) In the liver of tadpole treated with griseofulvin, a ferrochelatase inhibitor, the synthesis of heme a, but not cytochrome c oxidase protein, is inhibited. (2) The apocytochrome c oxidase which is formed in the liver of tadpole treated with griseofulvin is converted to the active holoenzyme by exogenously added heme a.     

How to discriminate between vibration syndrome and local fatigue of motorcyclists

Motorcyclists who work in some offices sometimes complained of coldness, pain and numbness of upper limbs. We studied how to discriminate between vibration syndrome and local fatigue of the motorcyclists. Subjects are 42 motorcyclists of an office in Aichi prefecture. 25 of them held several letters in their left hand when they delivered the letters. They complained of coldness, pain and numbness in the left upper limbs more than in the right limbs (p less than 0.01). We think that it is the local fatigue rather than the disorder of vibration syndrome that causes such symptoms. So it is very important to recognize the existence of local fatigue in order to know how to discriminate between vibration syndrome and local fatigue of the motorcyclists.