Effects of in vitro and in vivo supplementation with zinc on superoxide anion production in leukocytes

The effects of zinc on the rate of production of bactericidal O2- of polymorphonuclear leukocytes (PMN) in response to three different types of stimulating agents (serum-treated zymosan (STZ), Con A, and myristate) were studied. The percentage reduction of O2- production of PMN stimulated by STZ, Con A, and myristate were all reduced in response to Zn, irregardless of whether Zn was added to the reaction mixture immediately before SZT addition or following a prior 20 min. incubation of PMN in the presence of Zn. However, when Zn was introduced intraperitonially into guinea pigs before the collection of PMN from the animal, zinc treatment produced inhibition only in STZ-activated PMN; it produced no effect in O2- production of PMN stimulated by myristate, and it further augmented the O2- production stimulated by Con A.     

Comparative Study of Glial Marker Proteins in the Hypoplastic Cerebellum of Jaundiced Gunn Rats

The behavior of marker proteins of glial cells [alpha-enolase, beta-S100 protein, and glial fibrillary acidic protein (GFAP)] was investigated quantitatively by using enzyme immunoassay systems during the development of cerebellar hypoplasia in jaundiced Gunn rats. A neuronal marker protein, gamma-enolase, was also measured as a reference. At postnatal day 8 corresponding to the early stage of cerebellar damage, the amount of beta-S100 on a protein basis was significantly higher in jaundiced homozygotes (jj) than in control nonjaundiced heterozygotes (j+), whereas no differences in alpha- and gamma-enolases and GFAP were observed between the two groups of rats. At days 15 and 30, which correspond, respectively, to the advanced and late stages of cerebellar damage, the three glial proteins, especially GFAP, were higher and the neuronal protein was lower in the jj rat cerebellum than in the control. These results are consistent with the reported histological observations that neuronal cells are vulnerable and damaged by bilirubin, whereas glial cells seem to be less sensitive. On the other hand, the amounts of beta-S100 and alpha-enolase per cerebellum were significantly lower in jj rats at days 15 and 30, as in the case of gamma-enolase, whereas that of GFAP remained at the same level as the control at day 15 and showed a slight but significant decrease at day 30. The possibility is suggested that beta-S100 and GFAP may be available as biochemical indicators of glial cells, especially in the early and advanced stages of cerebellar damage, respectively, but that alpha-enolase is less available.     

Human corticotropin-releasing hormone test in normal subjects and patients with hypothalamic, pituitary or adrenocortical disorders

Human corticotropin-releasing hormone (hCRH) test was performed in 57 normal volunteers and 102 patients with hypothalamic, pituitary and adrenocortical diseases. Intravenous bolus injection of synthetic hCRH, 100 micrograms for adults or 1.5 micrograms/kg for children, increased plasma ACTH and cortisol levels in about 90% of normal subjects. In 47 patients with Cushing's disease, plasma ACTH tended to show an exaggerated response to hCRH and peak ACTH was the most frequent abnormal component among the several reaction parameters. Poor responders among normal subjects and patients with Cushing's disease had significantly higher plasma cortisol levels before CRH administration. Patients with hypothalamic hypopituitarism showed exaggerated response, whereas patients with primary pituitary lesion, isolated ACTH deficiency or adrenal Cushing's syndrome showed no ACTH response. These differences in the response of patients suggest the value of the hCRH test in their differential diagnosis.     

Retinoic acid promotes proliferation and chondrogenesis in the distal mesodermal cells of chick limb bud

Distal and proximal mesoderm of chick limb bud was respectively dissociated and cultured in the medium containing various concentrations of retinoic acid (RA). At low concentrations (5-50 ng/ml), RA promoted proliferation and chondrogenesis in the distal mesodermal cells. The distal cells of stage 20-24 limb buds were responsive to RA, although those of stages 25-27 were unresponsive. Both the cells of anterior and posterior regions of the distal mesoderm were responsive to RA, while the cells of proximal mesoderm were unresponsive. At higher concentrations, the growth-promoting effect of RA was reduced and chondrogenesis in the distal cells was rather inhibited. These results were discussed in relation to the role of RA as the morphogen in normal limb development and experimental duplicate formation.     

Radiation-induced peroxidation of lipid dissolved in organic solvent and its inhibition by alpha-tocopherol and cepharanthine

Effects of cepharanthine and alpha-tocopherol on radiation-induced peroxidation of lipids dissolved in methanol(MeOH)-chloroform (CHCl3)-H2O(v/v, 2/1/0.8) were examined. alpha-Tocopherol strongly inhibited radiation-induced peroxidation of lipids dissolved in MeOH-CHCl3-H2O. However, cepharanthine exhibited a weak inhibitory action in this system. The change in the absorption spectrum of alpha-tocopherol and cepharanthine by X-irradiation was measured. The reagents were dissolved in 95% EtOH acidified with 20 mM HCl and in MeOH-CHCl3-H2O. alpha-Tocopherol exhibited the change in its absorption spectrum in both systems, and seemed to be oxidized at a high rate by free radicals. However, cepharanthine slightly exhibited the change in its spectrum in MeOH-CHCl3-H2O, but not in acidified EtOH.     

A novel and remarkably thermostable ferredoxin from the hyperthermophilic archaebacterium Pyrococcus furiosus.

The archaebacterium Pyrococcus furiosus is a strict anaerobe that grows optimally at 100 degrees C by a fermentative-type metabolism in which H2 and CO2 are the only detectable products. A ferredoxin, which functions as the electron donor to the hydrogenase of this organism was purified under anaerobic reducing conditions. It had a molecular weight of approximately 12,000 and contained 8 iron atoms and 8 cysteine residues/mol but lacked histidine or arginine residues. Reduction and oxidation of the ferredoxin each required 2 electrons/mol, which is consistent with the presence of two [4Fe-4S] clusters. The reduced protein gave rise to a broad rhombic electronic paramagnetic resonance spectrum, with gz = 2.10, gy = 1.86, gx = 1.80, and a midpoint potential of -345 mV (at pH 8). However, this spectrum represented a minor species, since it quantitated to only approximately 0.3 spins/mol. P. furiosus ferredoxin is therefore distinct from other ferredoxins in that the bulk of its iron is not present as iron-sulfur clusters with an S = 1/2 ground state. The apoferredoxin was reconstituted with iron and sulfide to give a protein that was indistinguishable from the native ferredoxin by its iron content and electron paramagnetic resonance properties, which showed that the novel iron-sulfur clusters were not artifacts of purification. The reduced ferredoxin also functioned as an electron donor for H2 evolution catalyzed by the hydrogenase of the mesophilic eubacterium Clostridium pasteurianum. P. furiosus ferredoxin was resistant to denaturation by sodium dodecyl sulfate (20%, wt/vol) and was remarkably thermostable. Its UV-visible absorption spectrum and electron carrier activity to P. furiosus hydrogenase were unaffected by a 12-h incubation of 95 degrees C.     

The poly-alpha- and -beta-1,4-glucuronic acid moiety of teichuronopeptide from the cell wall of the alkalophilic Bacillus strain C-125.

Teichuronopeptide is a structural component of the cell wall of alkalophilic Bacillus strain C-125 and is a complex composed of polyglutamate and polyglucuronate. A structural analysis of the polyglucuronic acid moiety was carried out. Periodate oxidation and Smith degradation of the moiety, and enzymic analysis after reduction of glucuronic acid to glucose, revealed that glucuronic acid bound together with alternately alpha- and beta-1,4-linkages.