The Atp7b protein is a copper-transporting ATPase expressed predominantly in the liver and to a lesser extent in most other tissues. Mutations in the ATP7B gene lead to Wilson disease, a copper toxicity disorder characterized by dramatic build-up of intracellular hepatic copper with subsequent hepatic and neuro-logical abnormalities. Using homologous recombination to disrupt the normal translation of ATP7B, we have generated a strain of mice that are homozygous mutants (null) for the Wilson disease gene. The ATP7B null mice display a gradual accumulation of hepatic copper that increases to a level 60-fold greater than normal by 5 months of age. An increase in copper concentration was also observed in the kidney, brain, placenta and lactating mammary glands of homo-zygous mutants, although milk from the mutant glands was copper deficient. Morphological abnormalities resembling cirrhosis developed in the majority of the livers from homozygous mutants older than 7 months of age. Progeny of the homozygous mutant females demonstrated neurological abnormalities and growth retardation characteristic of copper deficiency. Copper concentration in the livers of the newborn homozygous null mutants was decreased dramatically. In summary, inactivation of the murine ATP7B gene produces a form of cirrhotic liver disease that resembles Wilson disease in humans and the 'toxic milk' phenotype in the mouse.
The characteristics of dialyzed and freeze-dried egg white that was dry-heated under various
conditions (70−125 °C, 0 min−6 h) were studied. The dry-heated egg whites (DHEWs, 120 °C)
showed the formation of insoluble aggregates (coagula) within 50 min, turbid soluble ones (50 min−2
h), and transparent soluble ones (2−6 h) according to the dry-heating times when solubilized at
10% concentration (pH 7.4) and reheated at 60 °C for 3.5 min. A transparent DHEW solution without
any coagula when reheated was obtained by using a shorter dry-heating time and elevating the
dry-heating temperature. It was also found that NaCl suppressed the turbidity development of
DHEW solution promoted by CaCl2. When 10% DHEW solutions (120 °C, >2 h) were mixed with
fresh egg white at the ratio of 1:1 in volume and heated at 60 °C for 3.5 min, coagulum formations
in their mixtures were inhibited. The patterns of native− and SDS−PAGEs and gel filtration suggest
that soluble aggregates of ovalbumin formed in the dry-heating process inhibit the formation of
ovotransferrin coagula.
Keywords: Egg white; dry-heating; heat coagulation; soluble aggregate
Dialyzed and freeze-dried egg white (FDEW) was dry-heated at 120 degrees C for up to 6 h. The inhibiting effects of the dry-heated egg white (DHEW) on the heat aggregation and coagulation of egg white (as 10% FDEW solution) and characteristics of the DHEW were examined. From the changes in turbidities and soluble protein contents of supernatant in various mixtures of 10% FDEW and DHEW solutions induced by heating (60 degrees C, 5 min), it was found that the inhibiting capacity increased with increases in the dry-heating time (DHT). The FDEW proteins were denatured with a mild conformational change (not secondary but tertiary structure) with the increase in DHT and aggregated partially. However, the more transparent solutions of DHEW containing soluble aggregates according to DHT were also obtained after heating. The transparency according to DHT came to be scarcely affected by the NaCl concentration and the dilution with diluents containing SDS, urea, and 2-mercaptoethanol. These findings suggest that the heat aggregations and coagulations of ovotransferrin and lysozyme in the FDEW were inhibited by their bindings with the soluble aggregates in DHEW.
When space (time) translation symmetry is spontaneously broken, the space crystal (time crystal) forms; when permittivity and permeability periodically vary with space (time), the photonic crystal (photonic time crystal) forms. We proposed the concept of photonic time crystal and rewritten the Maxwell’s equations. Utilizing Finite Difference Time Domain (FDTD) method, we simulated electromagnetic wave propagation in photonic time crystal and photonic space-time crystal, the simulation results show that more intensive scatter fields can obtained in photonic time crystal and photonic space-time crystal.
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