Premature induction of amylase in pancreas and parotid gland of growing rats by dexamethasone

Studies were made on changes in the contents of α-amylase (EC 3.2.1.1) in the pancreas and parotid gland of rats during postnatal devlopment, on the premature induction of this enzyme by hormones and on the existence of specific glucocorticoid receptors in these tissues.The amylase content in the pancreas increased from the 9th day after birth and reached the adult level on the 28th day, its content in the parotid gland increased rapidly from the 16th to 28th day after birth and then rose more gradually to the adult level.Injection of dexamethasone into rats 6–8 days after birth induced increase in the amylase of the pancreas but not the parotid gland. However, injection of dexamethasone into weanling rats 21–23 days after birth resulted in precocious induction of amylase in both tissues.Specific glucocorticoid receptors were detectable in the parotid gland of rats from 6 days after birth but were almost undetectable in the pancreas until adolescence.     

Respiration-dependent uncoupler-stimulated ATPase activity in castor bean endosperm mitochondria and submitochondrial particles

1. The uncoupler-stimulated ATPase activity of castor bean endosperm mitochondria and submitochondrial particles has been studied. The rate of ATP hydrolysis catalyzed by intact mitochondria was slow and little enhanced by addition of uncouplers at the concentration required for uncoupling the oxidative phosphorylation. ATPase activity was stimulated at higher concentrations of uncouplers.

2. 1-Anilinonaphthalene 8-sulfonate fluorescence was decreased when the mitochondria were oxidizing succinate. Carbonylcyanide-p-trifluoromethoxyphenylhydrazone and antimycin reversed the succinate-induced fluorescence diminution. ATP did not induce the fluorescence response.

3. The addition of succinate, NADH or ascorbate/N,N,N′,N′-tetramethyl-p-phenylenediamine as electron donor induced high ATPase activity in the presence of low concentrations of uncouplers. Stimulating effect of uncouplers was completely abolished by further addition of antimycin.

4. Submitochondrial particles were prepared by sonication. The particles catalyzed a rapid hydrolysis of ATP and carbonylcyanide-p-trifluoromethoxyphenylhydrazone at 10^-8 M did not stimulate the ATPase activity. Addition of succinate induced uncoupler-stimulated ATPase activity. The effect of succinate was completely abolished by further addition of antimycin.

5. The treatment of submitochondrial particles by trypsin or high pH also induced uncoupler-stimulated ATPase activity.

6. The above results were interpreted to indicate that ATPase inhibitor regulated the back-flow reaction of mitochondrial oxidative phosphorylation.     

Isolation of L-dynurenine 3-hydroxylase from the mitochondrial outer membrane of rat liver.

Outer membrane preparations of rat liver mitochondria were isolated, after the mitochondria had been prepared by mild digitonin treatment under isotonic conditions. L-Kynurenine 3-hydroxylase [EC 1.14.13.9] was solubilized on a large scale from outer membrane by mixing with 1% digitonin or 1% Triton X-100, followed by fractionation into a minor fraction I and a major fraction II by DEAE-cellulose column chromatography. The distribution of total L-Dynurenine 3-hydroxylase was roughly 20 and 80% in fraction I and II, respectively. Fraction I consisted of crude enzyme loosely bound to anion exchanger. In the present investigation, fraction I was not used because of its low activity and rapid inactivation. In contrast, fraction II consisted of crude enzyme with high activity, excluded from DEAE-cellulose column chromatography in the presence of 1 M KC1. In addition, fraction II was purified by Sephadex G-200 gel filtration and DEAE-Sephadex A-50 column chromatography with linear gradient elution, adding 1 M KC1 and 1% Triton X-100 to 0.05 M Tris-acetate buffer, pH 8.1. After isoelectric focusing, the purified enzyme preparation was proved to be homogeneous, since the L-kynurenine 3-hydroxylase fraction gave a single band on disc gel electrophoresis. The molecular weight of this enzyme was estimated to be approximately 200,000 or more by SDS-polyacrylamide gel electrophoresis and from the elution pattern on Sephadex G-200 gel filtration. A 16-Fold increase of the enzyme activity was obtained compared with that of the mitochondrial outer membrane. The isoelectric point of the enzyme was determined to be pH 5.4 by Ampholine isoelectric focusing.     

Nucleic acid metabolism in cold-treated wheat embryos

The incorporation of ₃₂P into nucleic acid fractions separatedon a MAK column was compared for normally germinated and cold-treatedwheat embryos. ₃₂P accumulation in DNA fraction was decreasedby cold treatment, although that in the RNA fractions was slightlypromoted. The synthesis of the fraction, probably mRNA, elutedafter the peak of heavy rRNA was enhanced in cold-treated embryosand suppressed when the embryos were cold-treated in the presenceof 8-azaguanine, an inhibitor of vernalization. (Received May 2, 1975; )     

Changes in nucleic acids, protein-nitrogen and amino-nitrogen of excised winter wheat embryos during vernalization

Embryos excised from winter wheat grains were vernalized for10–50 days with or without sugar (sucrose). Determinationswere made of fresh weight, protein-nitrogen, amino-nitrogen,RNA and DNA. There was no change in the contents of RNA of wheatembryos during the vernalization. The incorporation of ³²P intonucleic acid in wheat embryos during vernalization in the presenceof sugar was much higher than that of embryos vernalized withoutsugar. From these results we assumed that RNA turnover occurredduring the vernalization. There was no significant differencein the nucleotide composition of RNA extracted between the vernalizedand unvernalized embryos. The RNA of wheat embryos was separatedinto two fractions. Proportions of these two RNA fractions variedin the course of cold treatment, and similar changes were foundin developing wheat leaves. (Received July 25, 1974; )     

Fetal monitoring during maternal cardiac surgery with cardiopulmonary bypass.

Fetal cardiac activity was monitored with an external ultrasound transducer in two patients with clinical class III heart disease due to severe mitral stenosis complicated by pulmonary hypertension, undergoing open heart surgery with cardiopulmonary bypass in the 2nd trimester of pregnancy. Fetal distress was detected in one patient, who had mitral valvuloplasty, and was corrected by increasing the rate of blood flow, and the other patient had a mitral valve replacement but no fetal distress was noted. The postoperative course of both mothers and fetuses was uneventful.     

Synthesis of 6-Sulfur Analogues of Oxanosine and Closely Related Derivatives Thereof

Abstract

Novel β-D-ribofuranosides having a 5-substituted imidazo [4,5-d] [1,3]thiazine ring, including the S⁶-congener 3 of oxanosine 2, were synthesized for screening their anticancer and antiviral activities.     

Genetic and Anatomical Basis of the Barrier Separating Wakefulness and Anesthetic-Induced Unresponsiveness

A robust, bistable switch regulates the fluctuations between wakefulness and natural sleep as well as those between wakefulness and anesthetic-induced unresponsiveness. We previously provided experimental evidence for the existence of a behavioral barrier to transitions between these states of arousal, which we call neural inertia. Here we show that neural inertia is controlled by processes that contribute to sleep homeostasis and requires four genes involved in electrical excitability: Sh, sss, na and unc79. Although loss of function mutations in these genes can increase or decrease sensitivity to anesthesia induction, surprisingly, they all collapse neural inertia. These effects are genetically selective: neural inertia is not perturbed by loss-of-function mutations in all genes required for the sleep/wake cycle. These effects are also anatomically selective: sss acts in different neurons to influence arousal-promoting and arousal-suppressing processes underlying neural inertia. Supporting the idea that anesthesia and sleep share some, but not all, genetic and anatomical arousal-regulating pathways, we demonstrate that increasing homeostatic sleep drive widens the neural inertial barrier. We propose that processes selectively contributing to sleep homeostasis and neural inertia may be impaired in pathophysiological conditions such as coma and persistent vegetative states.     

The deoxygenations of tosylated adenosine derivatives with Grignard reagents

The reactions of 2'-O- or 3'-O-tosylated adenosines with Grignard reagents resulted in the formation of various products, which were deoxy or branched-chain deoxy sugar nucleosides, 1',2'-unsaturated nucleosides, 3'-deoxy-2'-keto sugar nucleosides, and so on. The convenient method for the synthesis of the 3'-deoxy-2'-keto adenine nucleoside is described.