Properties of the raw-starch digesting amylase of Aspergillus sp. K-27: a synergistic action of glucoamylase and alpha-amylase

Glucoamylase and alpha-amylase have been purified from a crude enzyme preparation of Aspergillus sp. K-27. The former was thermostable and seemed to have a "starch-binding site", judging from the results of a kinetic study, and the latter synergistically enhanced the degradation of starch granules with glucoamylase.     

A case of Graves' disease associated with an autonomously functioning thyroid nodule (AFTN) (Marine-Lenhalt syndrome) which spontaneously became a cold nodule

We report a 31-year-old female with Graves' disease associated with an autonomously functioning thyroid nodule (AFTN) (Marine-Lenhalt syndrome) in which the AFTN spontaneously became a cold nodule. Initially the patient was thyrotoxic and had diffuse goiter with an elevated radioiodine uptake. She became euthyroid following six months of antithyroid drug therapy, and in addition to diffuse goiter, the solitary hot nodule was palpable in the left lobe. Fourteen months later, hyperthyroidism recurred and the thyroid scan revealed diffuse radioiodine uptake with a cold area in the nodular region. The resected nodule showed extensive degeneration and the histological diagnosis was follicular adenoma with Graves' disease. We discussed the significance of recognizing the syndrome and also compared the frequency of spontaneous degeneration in AFTN and in solitary cold nodules.     

Hypercortisolism and the resistance to dexamethasone suppression during gestation

Maternal adrenocortical function was studied by measuring plasma cortisol and urinary free cortisol during gestation. Changes in suppressibility of pituitary-adrenocortical function were determined by dexamethasone administration. Urinary free cortisol as well as plasma cortisol increased during the course of gestation. The suppressibility by dexamethasone became less effective as pregnancy advanced. These results suggest that pregnant women have pituitary-adrenocortical hyperfunction and tissue refractoriness to glucocorticoid which increases during the course of gestation.     

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.     

A note on a theoretical study of erythrocyte sedimentation in inclined tubes

The expression for the sedimentation rate in inclined tubes given by Nakamura et al (Nakamura, H. and Kuroda, K. Keijo J. Med. 8, 256-296, 1937) is improved to be applicable to the problem that the falling velocity of a particle from the top wall of the tube v' differs from the one from the interface between the particle free layer and the suspended layer v. The effects of the shape at the bottom of the tube and the increase in height of the layer closely packed with particles are taken into account.     

Comparison of plasma prostanoid levels in the human cord artery in normal and fetal distressed deliveries

Prostaglandin E2 (PGE2), thromboxane B2 (TXB2; as a stable metabolite of TXA2), prostaglandin F2 alpha (PGF2 alpha) and 6-keto-PGF1 alpha (as a stable end product of prostacyclin) have been measured by using specific radioimmunoassay in the plasma of the cord artery immediately after delivery before the cord was clamped. Plasma prostanoid concentrations in normal deliveries (n = 8, as controls) were 24.8 +/- 2.6 (PGE2), 246.8 +/- 37.0 (TXB2), 122.2 +/- 13.3 (PGF2 alpha) and 82.1 +/- 7.7 (6-keto-PGF1 alpha) respectively (pg/ml, mean +/- s.e). On the other hand, in fetal distressed deliveries showing continuous bradycardia (n = 6), they increased significantly to 275.4 +/- 20.1 (PGE2), 948.6 +/- 102.5 (TXB2), 218.0 +/- 21.4 (PGF2 alpha) and 1498.6 +/- 298.4 (6-keto-PGF1 alpha) respectively (pg/ml, mean +/- s.e, p less than 0.005). However, both PGF2 alpha/PGE2 and TXB2/6-keto-PGF1 alpha ratios declined significantly from 4.70 +/- 0.33 to 0.68 +/- 0.05 and from 3.07 +/- 0.37 to 0.68 +/- 0.12 respectively (mean +/- s.e, p less than 0.005) in the fetal distressed group compared with those of the controls. From these results, it may be concluded that the cord artery, which is known as the patent source for the production of PGE2 and prostacyclin, did exert a sufficiently strong reaction to overcome the undesirable haemodynamic changes to maintain the fetal well-being in utero.     

The number of nucleotides required to determine the branching order of three species,with special reference to the human-chimpanzee-gorilla divergence

Summary A mathematical theory for computing the probabilities of various nucleotide configurations among related species is developed, and the probability of obtaining the correct tree (topology) from nucleotide sequence data is evaluated using models of evolutionary trees that are close to the tree of mitochondrial DNAs from human, chimpanzee, gorilla, orangutan, and gibbon. Special attention is given to the number of nucleotides required to resolve the branching order among the three most closely related organisms (human, chimpanzee, and gorilla). If the extent of DNA divergence is close to that obtained by Brown et al. for mitochondrial DNA and if sequence data are available only for the three most closely related organisms, the number of nucleotides (m^*) required to obtain the correct tree with a probability of 95% is about 4700. If sequence data for two outgroup species (orangutan and gibbon) are available, m^* becomes about 2600–2700 when the transformed distance, distance-Wagner, maximum parsimony, or compatibility method is used. In the unweighted pair-group method, m^* is not affected by the availability of data from outgroup species. When these five different tree-making methods, as well as Fitch and Margoliash's method, are applied to the mitochondrial DNA data (1834 bp) obtained by Brown et al. and by Hixson and Brown, they all give the same phylogenetic tree, in which human and chimpanzee are most closely related. However, the trees considered here are gene trees, and to obtain the correct species tree, sequence data for several independent loci must be used.     

Bacteriocinlike killing action of a temperate bacteriophage phiBA1 of Bacillus aneurinolyticus.

A new temperate phage, phiBA1, was isolated from Bacillus aneurinolyticus, phiBA1 had an icosahedral head with a diameter of about 70 nm and a tail about 20 nm long and contained a circularly permuted, linear duplex DNA of about 38 x 106 daltons. This phage showed two activities: bacteriocin-like killing activity against five strains of B. aneurinolyticus and normal temperate phage activity against three other strains. phiBA1 killed sensitive cells by a single-hit process. After adsorption of phiBA1 to cells sensitive to killing, the content of intracellular ATP increased for the first 5 min and then gradually decreased. Phage DNA injected into the cell immediately after infection was degraded rapidly. Killing was also caused by heavily UV-irradiated phiBA1. Killing-resistant mutants showed normal adsorption of phiBA1 and normal injection of the DNA with its instantaneous restriction. Our results indicate that the killing action of phiBA1 is different from the phenomenon of abortive infection and suggest that the killing might be caused by a proteinaceous component of phiBA1.     

Wounding Inhibits Protein Synthesis yet Stimulates Polysome Formation in Aged, Excised Pea Epicotyls

Wounding of aged, previously-excised pea epicotyl segments byremoval of the basal 1–2 mm resulted in a rapid (beginningwithin 15 min) recruitment of monosomes on to polysomes andan even more rapid (maximal between 6–12 min) inhibitionof protein synthesis in the remaining tissue. This inhibitionof protein synthesis in vivo did not appear to be an artefactcaused by the removal of highly active tissue (e.g., callus,contaminating bacteria), since wounds inflicted at a site distantfrom the region analyzed still elicited the response, and proteinsynthesis in the 1–2 mm slices (normally discarded) wasinhibited even more strongly than it was in the remaining tissue.The proportion of radioactive methionine in nascent chains (boundto polysomes) increased, while the production of completed polypeptidesdecreased, after wounding. Cycloheximide, a known inhibitorof the ribosome translocation/release process mimicked someof the effects of wounding. We interpret the results to indicatethat the initial effect of wounding is to inhibit translationby inhibiting the ribosome translocation/release process, whereasthe subsequent recovery in protein synthesis is brought aboutpartly by a recovery in ribosome translocation/release and partlyby enhanced initiation. ¹ Present address: Harvard-MIT Division of Health Science andTechnology, MIT, Cambridge, Massachusetts 02139, U.S.A. ² Present address: Institute of Agricultural Environment Control,College of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama790, Japan. (Received May 26, 1986; Accepted August 4, 1986)     

Metabolism of S-adenosylmethionine in rat hepatocytes: transfer of methyl group from S-adenosylmethionine by methyltransferase reactions

Treatment of rats with a methionine diet leads not only to a marked increase of S-adenosylmethionine synthetase in liver, but also to the increase of glycine, guanidoacetate and betaine-homocysteine methyltransferases. The activity of tRNA methyltransferase decreased with the increased amounts of methionine in the diets. However, the activities of phospholipids and S-adenosylmethionine-homocysteine methyltransferases did not show any significant change. When hepatocarcinogenesis induced by 2-fluorenylacetamide progresses, the activities of glycine and guanidoacetate methyltransferases in rat liver decreased, and could not be detected in tumorous area 8 months after treatment. The levels of S-adenosylmethionine in the liver also decreased to levels of one-fifth of control animals at 8 months. The uptake and metabolism of [methyl-3H]-methionine and -S-adenosylmethionine have been investigated by in vivo and isolated hepatocytes. The uptake of methionine and transfer of methyl group to phospholipid in the cells by methionine were remarkably higher than those by S-adenosylmethionine. These results indicate that phospholipids in hepatocytes accept methyl group from S-adenosylmethionine immediately, when it is synthesized from methionine, before mixing its pool in the cells.