The role of ankyrin in shape and deformability change of human erythrocyte ghosts

Human erythrocyte membranes (ghosts) from acid/citrate/dextrose preserved blood were digested with trypsin (protein/trypsin = 100:1) under hypotonic conditions and then analyzed by SDS-polyacrylamide gel electrophoresis. After digestion for about 20-30 s at 0 degree C, only ankyrin had disappeared and other bands including spectrin, actin, band 4.1 and band 3 remained intact. This observation was supported by electron micrographs showing that the horizontally disposed, filamentous structure was a little apart from the lipid bilayer and its components were not destroyed. In contrast to intact ghosts, treatment with chlorpromazine, or Mg-ATP did not induce shape change in these trypsin-treated ghosts. The number of transformable cells correlated closely with the amount of remaining ankyrin in the SDS-polyacrylamide gel electrophoresis pattern. Furthermore, the chlorpromazine- and Mg-ATP-induced decreases in viscosity of suspensions of erythrocyte ghosts were also prevented by trypsin treatment for 20-30 s at 0 degree C. These findings suggest that ankyrin plays an important role in the change in shape and deformability of erythrocyte ghosts. The molecular mechanism of drug-induced shape change and the role of undermembrane structure in regulating erythrocyte shape and deformability are discussed.     

Immune response induced by live attenuated varicella vaccine and short term follow-up on immunity of the vaccinated children

Live attenuated varicella vaccine (Oka strain, 500 to 750 PFU) was inoculated into 234 children with various underlying diseases. Varicella-zoster virus (VZV) specific immune adherence hemagglutination antibody developed in 95% of initially seronegative subjects. VZV specific cellular immune responses were detected in 91% of subjects within 6 weeks after vaccination. A preliminary survey of 46 vaccinated normal-risk subjects during the first and the third year revealed excellent protection with the exception of one case who had not shown any antibody response at the fourth week.     

Chronic ethanol administration decreases fatty acyl-CoA desaturase activities in rat liver microsomes

The Δ⁹-desaturase system in liver microsome from rats treated chronically with ethanol was studied. Stearoyl-CoA desaturase activity decreased by 80% and palmitoyl-CoA desaturase activity was not detectable in microsomes from ethanol-fed rats, while activities of electron transport components such as NADH-cytochrome c and NADH-ferricyanide reductases remained unchanged. However, chronic ethanol administration resulted in an adaptive induction of the activity of NADPH-cytochrome c reductase and the contents of cytochrome b₅ and P-450. The activity of the terminal component (cyanide-sensitive factor; CSF) of the desaturase system was greatly depressed by ethanol treatment. The NADH/NAD ratio in microsomes of ethanol-fed rats increased over 2-fold. These results suggest that, during chronic ethanol ingestion, decreased activities of Δ⁹-desaturases are due mainly to a decreased content of the terminal component of the desaturase system.     

Prenatal diagnosis of GM1-gangliosidosis: Biochemical manifestations in fetal tissues

Summary A prenatal diagnosis of G_M1-gangliosidosis was made in a pregnancy at risk, on the basis of a deficiency of -galactosidase activity demonstrated in cultured aminiotic fluid cells. Biochemical analyses were performed in the aborted fetus. G_M1-ganglioside -galactosidase activity was reduced to 1% of the control value in both the brain and liver of the affected fetus. Lamellar bodies suggestive of membranous cytoplasmic bodies were found in cells of basal ganglions, while the accumulation of G_M1-ganglioside in the brain was not remarkable.     

Presence of dynorphin-like immunoreactivity in rat pituitary gland and hypothalamus

Using a highly specific and sensitive radioimmunoassay for dynorphin(1-13), dynorphin-like immunoreactivity (dynorphin-LI) was detected in rat pituitary and hypothalamus. Gel chromatographic studies on Sephadex G-50 revealed three components of dynorphin-LI with molecular weights of approximately 7500-9500 (big dynorphin), 3500-5500 (intermediate dynorphin) and 1600-1900 (small dynorphin), the latter of which eluted at the same position as authentic dynorphin contamination in porcine ACTH extracts (Sigma). Dynorphin-LI in rat anterior pituitary existed mainly as big dynorphin, whereas dynorphin-LI in rat intermediate-posterior pituitary and hypothalamus eluted mainly at the position of authentic small dynorphin.     

Effects of dibromothymoquinone and bathophenanthroline on flash-induced cytochrome f oxidation in spinach chloroplasts

The effects of several electron transport inhibitors on themagnitude and kinetics of cytochrome f oxidation induced byflash illumination were studied in the - and -band regions.On the flash excitation only a fraction of cytochrome f presentin the chloroplasts was oxidized with a half time of 0.1 to0.3 msec and then reduced with a half time of 10 to 25 msec. Dibromothymoquinone (DBMIB) at concentrations which severelysuppressed the reduction of cytochrome f approximately doubledthe magnitude of cytochrome f oxidation caused by a flash, mainlyby inducing an additional slow oxidation of cytochrome f witha half time longer than 1 msec. Enhancement of the cytochromef oxidation was also observed in the presence of bathophenanthroline.Such enhanced oxidation in duced by the two inhibitors was largelydiminished with the addition of reduced 2,6-dichlorophenolindophenolwhich accelerated cytochrome f reduction. In contrast, the inhibitionof cytochrome f reduction by 3-(3,4-dichlorophenyl)-1,1-dimethylurea(DCMU) was not associated with an increase in the magnitudeof cytochrome f oxidation. However, addition of DBMIB to theDCMU-poisoned chloroplasts enhanced cytochrome f oxidation,suggesting that this is related to a block of the electron transportbetween plastoquinone and cytochrome f. The results are explainedby assuming the occurrence of an electron carrier between plastoquinoneand cytochrome f. (Received May 10, 1978; )     

Linkage of Mercury, Cadmium, and Arsenate and Drug Resistance in Clinical Isolates of Pseudomonas aeruginosa

Of the 787 isolates, 99.8% were metal resistant, with most (99.5%) showing multiple resistance. Fifty-three percent of the isolates were both metal and drug resistant, whereas only 19% were metal resistant and drug sensitive.     

Free amino acid changes in the cerebral cortex of experimental uremic rat

The levels of free amino acids in the cerebral cortex of acute and chronic uremic rats were examined. Amino acids significantly elevated were aspartate, glutamine, glycine, histidine, ornithine, phenylalanine, phosphoethanolamine and taurine, whereas 1-methyl histidine and 3-methyl histidine were specifically detected in uremic rats. Glutamate, arginine and carnosine disclosed a significant reduction. There was no change in the concentrations of γ-aminobutyrate and alanine. The above findings were essentially identical in both acute and chronic uremia. It was conjectured that these changes of amino acid levels in the brain might participate in the progress of uremic encephalopathy.     

Isolation and characterization of plasma membrane from lactating bovine mammary gland

Plasma membranes were isolated from lactating bovine mammary gland. Two crude membrane fractions; medium/d 1.033 (light membrane) and 1.033/1.053 interfaces (heavy membrane), were obtained by Ficoll density gradient centrifugation of osmotically washed microsomal fraction. Two crude membranes were further purified separately by sucrose density gradient centrifugation. Both light and heavy membranes banded at a sucrose density of 1.14. The purified membranes appeared as heterogeneous smooth membrane vesicles on electron microscopy. The contaminating suborganelles were not detected. The yield of the purified membranes relative to the homogenate was 1.2%. The degree of purity of the membranes was shown by a great increase in the specific activity of 5′-nucleotidase over the homogenate of 20-fold for light membrane and of 16-fold for heavy membrane. The relative activities of Mg²⁺-ATPase, (Na⁺ + K⁺)-ATPase, γ-glutamyl transpeptidase, phosphodiesterase I, akaline phosphatase and xanthine oxidase were also high (12–18-times) and nearly 20% of these enzymes was recovered. The activity of marker enzyme for mitochondria, endoplasmic reticulum and Golgi apparatus was very low, while that of acid phosphatase for lysosome was relatively high (5-times). DNA and RNA contents were very low. The major polypeptides rich in other suborganelles were not detected profoundly in the membrane fraction and the polypeptide compositions in both light and heavy membranes were similar upon SDS-polyacrylamide gel electrophoresis.