Freeze-preservation of rice cells: A physiological study of freeze-thawed cells

Rice ( Oryza sativa L.) cells returning to in vitro culture after preservation at superlow temperature in liquid nitrogen are characterized by a number of physiological alterations. These include: reduction in respiration and glucose uptake, loss of intracellular potassium, decrease in the cellular level of key metabolites (ATP, glucose-6-phosphate and pyruvate) and fragility of protoplasts following the action of cell wall-degrading enzymes.
Nevertheless, cell growth resumes after a short lag phase (2–4 days) with an actual 70–100% cell survival, thus indicating that the observed damage is not lethal and can be repaired in a short time.     

The electrolytic preparation of bioactive radioiodinated parathyroid hormone of high specific activity.

A technique for the preparation of microgram quantities of bovine parathyroid hormone (bPTH) labeled with carrier-free ¹²⁵I to a specific activity of 1300 Ci/mmol is described. A restructured and simplified apparatus was used for electrolytic iodination, making it feasible to use reaction volumes of 100 to 200 ml. The miniaturized setup requires only a small platinum crucible connected via an agar-KCl salt bridge to a saturated KCl solution, a battery to drive the reaction, and a voltmeter to monitor the potential difference between the reference-saturated KCl solution (via a calomel electrode) and the platinum crucible. The [¹²⁵I]-labeled bPTH elutes as a single species when chromatographed on a Biogel P-10 column equilibrated in 3 m guanidine HCl-2.3 m formic acid, and it retains full biologic activity when bioassayed in vivo. It is evident that bPTH labeled to a high specific activity with ¹²⁵I does not suffer in regard to its biological potency.     

Fat metabolism in higher plants. Further characterization of wheat germ acetyl coenzyme A carboxylase.

Wheat germ acetyl CoA carboxylase was purified 600-fold over the crude homogenate. The purified enzyme gave rise to complex electrophoretic patterns in dissociating gels. As isolated, the activity of wheat germ acetyl CoA carboxylase exhibited profound dependence on the composition of the reaction mixture. In addition to the substrates MgATP, HCO₃, and acetyl CoA, the enzyme required both free Mg²⁺ and K⁺ for optimal activity. The effects of the two ions were additive. At pH 8.5, Mg²⁺ activated the carboxylase by adding to the enzyme prior to the other reactants in an equilibrium ordered reaction mechanism.     

Coupled transepithelial sodium and potassium transport across isolated frog skin: Effect of ouabain,amiloride and the polyene antibiotic filipin

Summary Addition of the polyene antibiotic filipin (50 m) to the outside bathing solution (OBS) of the isolated frog skin resulted in a highly significant active outward transport of K⁺ because filipinper se increases the nonspecific Na⁺ and K⁺ permeability of the outward facing membrane. The K⁺ transport was calculated from the chemically determined changes in K⁺ concentrations in the solution bathing the two sides of the skin. The active transepithelial K⁺ transport required the presence of Na⁺ in the OBS, but not in the inside bathing solution (IBS), and it was inhibited by the Na⁺, K⁺-ATPase inhibitor ouabain. The addition of Ba⁺⁺ to the IBS in the presence of filipin in the OBS resulted in an activation of the transepithelial K⁺ transport and in an inhibition of the active Na⁺ transport. This is in agreement with the notion that Ba⁺⁺ decreases the passive K⁺ permeability of the inward facing membrane. In the presence of amiloride (which blocks the specific Na permeability of the outward facing membrane) and Ba⁺⁺ there was a good correlation between the active Na⁺ and K⁺ transport. It is concluded that the active transepithelial K⁺ transport is carried out by a coupled electrogenic Na–K pump, and it is suggested that the pump ratio (Na/K) is 1.5.     

X-Linked mental retardation with fragile X. a pedigree showing transmission by apparently unaffected males and partial expression in female carriers

Summary A large family is reported in which mental retardation associated with the fragile site at Xq28 was found. Three normal males seemed to have transmitted the trait through their daughters to affected grandchildren.A total of 19 family members were investigated cytogenetically. Mentally retarded males showed macroorchidism and the fragile X. Three mentally retarded females were found, with the fragile X in a high percentage of cells; in contrast, the obligate carriers showed no or only few cells with the fragile X.     

Interactions among nickel,copper, and iron in rats

In two fully-crossed, three-way, two-by-three-by-three, factorially arranged experiments, female weanling rats were fed a basal diet supplemented with iron at 15 and 45 μg/g, nickel at 0, 5, and 50 μg/g, and copper at either 0, 0.5, and 5 μ/g (Expt. 1) or 0, 0.25, and 12 μg/g (Expt. 2) A gram of basal diet contained in Expt. 1 approximately 16 ng of nickel, 2.3 μg of iron, and 0.47 μg of copper; and in Expt. 2, 20 ng of nickel, 1.3 μg of iron, and 0.39 μg of copper. Expt. 1 was terminated at 11 weeks, and Expt. 2 at 8 weeks because, at those times, some rats fed no supplemental copper and the high level of nickel began to lose weight, or die from heart rupture. The findings demonstrated that relationships are complex among nickel, copper, and iron. Nickel interacted with copper and this interaction was influenced by dietary iron. Signs of copper deficiency were more severe when nickel was supplemented to the diet provided that copper deprivation was neither very severe nor mild. Iron deprivation apparently enhanced the antagonism by exacerbating copper deficiency. Signs of copper deficiency that were made more severe by nickel supplementation were depressed weight gain (Expt. 2), hematocrit (Expt. 1), hemoglobin, and plasma alkaline phosphatase activity; and elevated ratios of heart wt/body wt, kidney wt/body wt, and liver wt/body wt. Because nickel and copper have similar physical and chemical properties, the interactions between those two elements were probably the result, of isomorphous replacement of copper by nickel at various functional sites that interfered with some biological processes.     

A newborn child with karyotype 47,XX,+der(12) (12pter→12q12::8q24→8qter),t(8;12) (q24;q12) pat

Summary A case of Meckel or Gruber syndrome is reported, together with a survey of the relevant literature of recent years (1971–1977), in reference to a probably autosomal recessive inheritance of this malformation.     

Effects of PTH and Ca2+ on renal adenyl cyclase

The effects of calcium ion on the adenylate cyclase system was studied in isolated, renal basal-lateral plasma membranes of the rat. Bovine parathyroid hormone (bPTH) and a guanyl triphosphate analogue, Gpp(NH)p were used to stimulate cyclase activity. Under conditions of maximal stimulation, calcium ions inhibited cyclic adenosine monophosphate (cAMP) formation, the formation rate falling exponentially with the calcium concentration. Fifty percent inhibition of either bPTH- or Gpp(NH)p-stimulated activity was given by approximately 50 μM Ca⁺⁺. Also the Hill coefficient for the inhibition was close to unity in both cases. The concentration of bPTH giving half-maximal stimulation of cAMP formation (1.8 × 10^?8 M) was unchanged by the presence of calcium. These data suggest that calcium acts at some point other than the initial hormone-receptor interaction, presumably decreasing the catalytic efficiency of the enzymic moiety of the membrane complex.     

Liver-cell-membrane autoantibody specific for inflammatory liver diseases.

With an immunofluorescence technique using rabbit hepatocytes isolated by a non-enzymatic method an autoantibody directed against liver-cell-membrance was identified. Sera from 361 patients with various liver diseases and 274 patients with primary non-hepatic diseases-many associated with non-organ-specific auto-antibodies-were examined. The antibody (LMA) was found in 27 out of 72 patients with hepatitis-B-surgace antigen (HBsAg)-negative chronic active hepatitis and in 17 out of 28 patients with HBsAg-negative non-alcoholic cirrhosis. Only two patients had LMA and HBsAg, and both had chronic active hepatitis. One patient with extrhepatic disease was found to have LMA, and this patient had biochemical evidence of liver disease. Hence there is a close correlation between the presence of LMA and HBsAg-negative chronic inflammatory liver diseases and its detection may help in diagnosis.