Differential subcellular localization of ACTH and α-MSH in corticotropes of the rat anterior pituitary

Summary Specific antisera to -melanotropin (-MSH) and corticotropin (ACTH 1-39) were used to obtain immunocytochemical evidence for the differential localization of -MSH and ACTH in the secretory granules of corticotropes of rat anterior pituitary. The specificity of the antisera was established by binding ¹³¹I-labeled -MSH and ACTH 1-39 to their respective antisera. Double-labeling immunocytochemistry (for -MSH, ferritin; for ACTH, colloidal gold) was performed. Some secretory granules were labeled with ferritin particles (-MSH), whereas others contained gold particles (ACTH). Only a few granules showed both ACTH and -MSH. In typical corticotropes (stellate in form with a small number of secretory granules aligned along the cell periphery) only some of the secretory granules that were labeled with anti-ACTH serum were also immunoreactive to anti--MSH. In atypical corticotropes (polygonal in shape and containing a large number of secretory granules) almost all of the immunoreactive ACTH secretory granules were also positive to anti--MSH serum. An intermediate type of corticotrope was observed containing a small number of secretory granules, almost all of which were labeled with anti--MSH. Thus, rat anterior pituitary corticotropes may be classified into three types according to the distribution and content of -MSH. The light-microscopic immuncytochemistry provided similar results.     

Substance-P-like immunoreactive subepithelial nerve plexuses in the labial mucosa of the mouse

Substance P (SP)-like immunoreactivity was examined in the lower labial mucosa of the mouse by using the whole-mount technique. The density and design of subepithelial nerve plexuses containing SP differed depending on portions of the lower labial mucosa.     

Reversed-phase HPLC determination of chlorophyll a' and phylloquinone in Photosystem I of oxygenic photosynthetic organisms. Universal existence of one chlorophyll a' molecule in Photosystem I.

Chlorophyll (Chl) a', the C132-epimer of Chl a, is a constituent of the primary electron donor (P700) of Photosystem (PS) I of a thermophilic cyanobacterium Synechococcus (Thermosynechococcus) elongatus, as was recently demonstrated by X-ray crystallography. To determine whether PS I of oxygenic photosynthetic organisms universally contains one molecule of Chl a', pigment compositions of thylakoid membranes and PS I complexes isolated from the cyanobacteria T. elongatus and Synechocystis sp. PCC 6803, the green alga Chlamydomonas reinhardtii, and the green plant spinach, were examined by simultaneous detection of phylloquinone (the secondary electron acceptor of PS I) and Chl a' by reversed-phase HPLC. The results were compared with the Chl a/P700 ratio determined spectrophotometrically. The Chl a'/PS I ratios of thylakoid membranes and PS I were about 1 for all the organisms examined, and one Chl a' molecule was found in PS I even after most of the peripheral subunits were removed. Chl a' showed a characteristic extraction behaviour significantly different from the bulk Chl a in acetone/methanol extraction upon varying the mixing ratio. These findings confirm that a single Chl a' molecule in P700 is the universal feature of PS I of the Chl a-based oxygenic photosynthetic organisms.     

Assembly of the mitochondrial membrane system. Characterization of nuclear mutants of Saccharomyces cerevisiae with defects in mitochondrial ATPase and respiratory enzymes.

Mutants of Saccharomyces cereviaiae showing defects in cytochrome oxidase, coenzyme QH2-cytochrome c reductase, and rutamycin-sensitive ATPase are described. The mutations have been established to be nuclear, based on complementation with a cytoplasmic petite tester strain and 2:2 segregation of tetrads. Genetic analysis indicate the coenzyme QH2-cytochrome c reductase and cytochrome oxidase mutants fall into 9 and 10 different complementation groups, respectively. The mutants also form distinct classes based on absorption spectra of the mitochondrial cytochromes. Two of the ATPase mutants lack detectable F1 ATPase, while the third synthesizes F1 but does not integrate it into a membrane complex. The latter mutant is missing one of the mitochondrially synthesized subunits of the rutamycin-sensitive ATPase complex.     

Assembly of the mitochondrial membrane system: isolation of nuclear and cytoplasmic mutants of Saccharomyces cerevisiae with specific defects in mitochondrial functions.

A selection procedure is described which permits a large number of Saccharomyces cerevisiae mutants to be screened for specific lesions in mitochondrial respiratory enzymes and the adenosine triphosphatase. The method has been used to isolate nuclear mutant strains with specific lesions in coenzyme QH2-cytochrome c reductase, cytochrome oxidase, and adenosine triphosphatase. In addition, two cytoplasmic mutants have been found whose primary defect is in cytochrome oxidase, and others have been found that show variable degrees of abnormalities in their mitochondrial translation products.     

Studies on enantioselective hydrolysis of the acetic ester of a secondary alcohol with Arthrobacter lipase

Summary Characteristics of the enantioselective hydrolysis of the acetic ester of 4-hydroxy-3-methyl-2-(2-propynyl)-2-cyclopentenone (HMPC) by Arthrobacter lipase were investigated in a water/oil biphasic reaction mixture. Kinetic studies revealed that the strict enantioselectivity was entirely due to a difference in the catalytic constants for the enantiomeric substrates and that (S)-HMPC acetate acted as a competitive inhibitor. The comparison of enantioselectivity for the acetates of HMPC analogues indicated that hydrophobic substituents in the HMPC molecule were essential for the strict enantioselectivity.Biological preparation of an optically active alcohol. Part II     

Production of Tropane Alkaloids by Hairy Root Cultures of Scopolia japonica

Hairy root clones of Scopolia japonica were established by selection of adventitious roots formed on the root segments inoculated with Agrobacterium rhizogenes strain 15834. Twenty-nine isolated hairy root clones displayed various phenotypes characterized by growth rate, opine production and tropane alkaloid production. Of these, two highly alkaloid productive clones SI and S22 were examined for their growth rate and alkaloid productivity under various cultural conditions. When the most scopolamine-productive clone SI was cultured for 4 weeks at 25°C in the dark, the weight of the root tissue was increased by 40 times and the content of scopolamine reached a level of 0.5% on a dry weight basis in each optimum medium. On culture of the most hyoscyamine-productive clone S22 under the same conditions as with S1, the weight was increased by 102 times and the content of hyoscyamine was 1.3% on a dry weight basis in each optimum medium.     

Effect of electrical stimulation on musculoskeletal systems; a meta-analysis of controlled clinical trials

This study was a meta-analysis to examine whether electrical stimulation has specific effects in the healing of musculoskeletal repair process and in the diminution of symptoms with bone and joint disorders. Using MEDLINE (1966-1999) and EMBASE (1985-1999) a search for articles was carried out with four medical subject headings. Data were extracted from all the accessed articles and additionally collected from appropriate journal lists. A total of 20 randomized controlled trials on bones was identified which assessed healing of fractures, bone graft, and other conditions; and 29 randomized controlled trials on soft tissues and joints were also found, dealing with healing of skin wounds or dermal ulcers, soft tissue injury, and other conditions. Using criteria through which the quality of studies was assessed, the content of the articles was reorganized into a tabular form. The majority of the identified articles reported positive findings, but all the trials showed methodological flaws to some extent. Because of heterogeneity of the studies and the various outcome measurements, pooling of only part of the data was performed. The combined results of 12 trials on bones and 16 trials on soft tissues, the cases in which major endpoints were mainly union or healing rate, revealed statistically significant effects. The studies in this review had some methodological limitations, and the selected pooled trials do not constitute acceptable proof that electrical stimulation has specific effects on health. However, one cannot ignore the statistically significant positive findings reported in the trials, from which extracted data were able to be combined.