Monodehydroascorbate Reductase in Spinach Chloroplasts and Its Participation in Regeneration of Ascorbate for Scavenging Hydrogen Peroxide

The primary reaction product of chloroplast ascorbate peroxidaseactivity was shown to be monodehydroascorbate radical (MDA).MDA reductase (EC 1.6.5.4 [EC] ) was localized in spinach chloroplaststroma. The MDA reductase activity of spinach chloroplasts,using NAD(P)H as electron donor, could account for the regenerationof ascorbate from MDA produced by ascorbate peroxidase activity.In the absence of MDA reductase, MDA disproportionated to ascorbate(AsA) and dehydroascorbate (DHA). The DHA was reduced to AsAby DHA reductase (EC 1.8.5.1 [EC] ) in chloroplasts. Both NADH andNADPH served as the electron donor of partially purified MDAreductase from spinach leaves. (Received September 24, 1983; Accepted January 23, 1984)     

An immunohistochemical study of epithelial cells in the posterior lobe and pars tuberalis of the human adult pituitary gland

Summary Pituitary glands were examined using reference staining (hematoxylin and eosin, periodic acid-Schiff and alcian blue) and the peroxidase-labeled antibody method, for 1) invading anterior cells in the posterior lobe, 2) intermediate colloid forming follicles, and 3) pars tuberalis cells.The results showed: 1) that the majority of cases possessed invading anterior cells of various amount. Most of these cells were positive for ACTH^1–18, ACTH^17–39 and -MSH. However, on a few occasions, scattered GH, PRL, FSH, FSH, LH and even TSH cells were also present. 2) Colloid forming follicular cells were mostly ACTH cells, but also contained occasional other hormone-secreting cells. Hormone negative cells were correlated with salivary type epithelium. Well established acinic type salivary glands and ciliated epithelium were negative for any hormones immunohistochemically. 3) Pars tuberalis cells were predominantly gonadotrophs but also included TSH and ACTH cells. Some cells appeared to contain both FSH and LH. When these cells underwent squamous metaplasia, they seemed to lose their hormone secreting activity.Part of this study was supported by a Grant-in-Aid for Cancer Research from the Ministry of Education, Science and Culture, Japan     

A specific concanavalin A-mediated binding of bovine serum α-mannosidase to cultured human skin fibroblasts

A specific elevation of cell-associated α-mannosidase was observed in human skin fibroblasts cultured with concanavalin A for 12–72 hours. There was a latency of several hours before the increase of the enzyme activity occurred. When the cells were washed with α-methylmannoside, α-mannosidase activity was not increased. Other lysosomal enzymes including β-mannosidase showed a slight decrease in activity. It was concluded that the elevation of this enzyme activity was the result of a specific binding to the cell surface mediated by concanavalin A.     

Effect of auxin and other hormones on the metabolic response to wounding in sweet potato roots

In roots of sweet potato (Ipomoea batatas Lam. cv. Kokei 14),the metabolic response to wounding was remarkable only in theproximal side. We assumed that the polarity resulted from apolar movement of indole-3-acetic acid (IAA) produced in thecut surface (8). As the metabolic response was slight in thedistal side, the effect of IAA and the other plant hormoneson the development of various enzyme activities was examinedin this side. Increases in activities of L-phenylalanine ammonia-lyase,acid invertase, NADPHa₂ : cytochrome c oxidoreductase, peroxidase,cytochrome c : O₂ oxidoreductase and o-diphenol oxidase, whichdeveloped in response to wounding, were stimulated by the treatmentwith IAA. Gibberellic acid had a stimulative effect on the developmentof only acid invertase activity. Abscisic acid and kinetin hadlittle effect. The results strongly support our hypothesis thatIAA plays an important role in the metabolic response to wounding. (Received September 29, 1979; )     

Production of anti-self-H-2 antibodies by C3D2F1 mice hyperimmune to L cell/L1210 hybrids and L1210 leukemia cells

During the course of immunization of (C3H × DBA/2)F₁ mice (genotype H-2^k/b) with L cell (H-2^k/k)/L1210 leukemia cell (H-2^d/d) hybrids and L1210 leukemia cells, some of them produced a good titer of anti-self-H-2 (H-2^d) antibodies. Antigens recognized by this anti-self-H-2 antiserum were shown to be controlled by the H-2K-IA-IB-IJ-IE subregions of the H-2^d but not H-2^k nor H-2^b haplotypes of parental as well as F₁ origins and to have a tissue distribution identical to that of class 1 H-2 (H-2K/D) antigens.     

Electrophoresis of mutant proteins in inherited diseases

The electrophoretic approaches for detection of mutant proteins in inherited diseases are briefly reviewed and discussed. Mutation of a protein, known to be associated with a specific inherited disease, is detected by immunoblotting, immunoprecipitation or enzyme staining, combined with various electrophoretic techniques. Some instrumental and technological devices for two-dimensional electrophoresis have been reported for the screening of mutant proteins in diseases of currently unknown etiology.     

Purification and properties of extracellularβ-fructofuranosidases fromAureobasidium sp. ATCC 20524

Summary Two extracellular -fructofuranosidases (E-1 andE-2) fromAureobasidium sp. ATCC 20524, producing 1-kestose (1^F--fructofuranosyl-sucrose) from sucrose, were purified to homogeneity. Molecular weights of the enzymes were estimated to be about 304000 (E-1) and 315000 (E-2) Da by gel filtration. The enzymes contained 33% (w/w) (E-1) and 27% (w/w) (E-2) carbohydrate. TheK _m values for sucrose ofE-1 andE-2 andE-2 were 0.34 and 0.28 M, respectively. were 0.34 and 0.28 M, respectively. The enzymatic profiles of these enzymes were almost identical to intracellular enzymesP-1 andP-2 except for the differences in carbohydrate content andK _m values ofE-2 andP-2.     

Application of enzyme-linked immunosorbent assay for mass examination of strongyloidiasis in okinawa, Japan

The enzyme-linked immunosorbent assay was tested to evaluate whether it could be applicable in screening for mass examination of strongyloidiasis. A total of 2906 inhabitants in three areas (858 in Gushikawa Village, 849 in Nakazato Village and 1199 in Sashiki Town) were screened by the enzymatic assay and approximately 11–30% (11.8% in Gushikawa, 17.0% in Nakazato and 27.7% in Sashiki) were considered to be antibody positive. In the parasitological follow-up examinations of those who were antibody positive, actual infection was found in more than half (51%) the subjects. The overall infection rates estimated from the results reached 5.8% in Gushikawa, 9.1% in Nakazato and 14.0% in Sashiki (mean = 10.4%). The infection rates were significantly higher than those in previous surveys conducted in the same areas. The ELISA technique was found to be useful for strongyloidiasis screening and for seroepidemiological purposes in Okinawa.     

Prevalence of spotted fever group rickettsia antibody in Apodemus speciosus captured in an endemic focus in Miyazaki Prefecture, Japan

Fourteen of Apodemus speciosus (large Japanese field mouse) were captured near the place where one of the patients with spotted fever group rickettsiosis had been infected, in Takaoka town, Miyazaki Prefecture. In the town, four human cases were reported. All of the mice had antibodies against Rickettsia japonica and R. montana. The incidence of the antibody was significantly higher in Apodemus mice in the area than in those from nonendemic area.