What is claimed is:
1. A mutant pro-neurotrophin for use in intracellular processing of a corresponding growth factor having improved secretion efficiency as compared to a wild-type growth factor, wherein the wild-type pro-neurotrophin has an asparagine residue at a position 8 amino acids upstream from the site of cleavage for the mature growth factor, the mutant pro-neurotrophin comprising a polypeptide in which the wild-type asparagine residue is replaced by a basic residue.
2. The mutant pro-neurotrophin according to claim 1, wherein the basic residue is serine.
3. The mutant pro-neurotrophin according to claim 1, wherein the corresponding growth factor is selected from the group consisting of neurotrophins NGF, NT-3 and BDNF.
4. The mutant pro-neurotrophin according to claim 1, wherein the polypeptide is a recombinant one, and the replacement of the wild-type asparagine is made by mutation of a polynucleotide encoding the wild-type pro-neurotrophin.
5. A mutant pro-neurotrophin for use in intracellular processing of a corresponding growth factor having improved secretion efficiency as compared to a wild-type growth factor, wherein the wild-type pro-neurotrophin has an asparagine residue at a position 4 amino acids upstream from the site of cleavage for the mature growth factor, the mutant pro-neurotrophin comprising a polypeptide in which the wild-type asparagine residue is replaced by a basic residue.
6. The mutant pro-neurotrophin according to claim 5, wherein the basic residue is serine.
7. The mutant pro-neurotrophin according to claim 5, wherein the corresponding neurotrophin is NT-45.
8. The mutant pro-neurotrophin according to claim 5, wherein the polypeptide is a recombinant one, and the replacement of the wild-type asparagine is made by mutation of a polynucleotide encoding the wild-type pro-neurotrophin.
9. A mutant pro-neurotrophin precursor polypeptide selected from the group of polypeptides consisting of SEQ.ID.Nos. 1, 3, 5 and 7.
10. A mutant pro-neurotrophin comprising the precursor polypeptide of claim 5, joined by a cleavage site to a corresponding mature growth factor.
11. A polynucleotide encoding a mutant pro-neurotrophin, wherein the polynucleotide differs in nucleotide sequence from wild-type by replacement of the codon encoding a target asparagine residue, at a position 8 amino acids upstream from the site of cleavage for the corresponding growth factor, with a substitution codon encoding a basic residue.
12. The polynucleotide according to claim 7, wherein the substitution codon encodes serine.
13. The polynucleotide according to claim 7, wherein the corresponding neurotrophin is selected from the group consisting of NGF, NT-3 and BDNF.
14. The polynucleotide of SEQ.ID.No. 16.
15. A polynucleotide encoding a mutant pro-neurotrophin, wherein the polynucleotide differs in nucleotide sequence from wild-type by replacement of the codon encoding a target asparagine residue, at a position 4 amino acids upstream from the site of cleavage for the corresponding neurotrophin, with a substitution codon encoding a basic residue.
16. The polynucleotide according to claim 15, wherein the substitution codon encodes serine.
17. The polynucleotide according to claim 15, wherein the corresponding neurotrophin is NT-45.
18. A recombinant expression vector containing the polynucleotide of any of claims 11, 14 or 15.
19. A host cell containing the recombinant expression vector of of any of claims 11, 14 or 15.
20. A pharmaceutical composition comprising the recombinant expression vector of of any of claims 11, 14 or 15.
21. A pharmaceutical composition comprising the host cell of any of claims 11, 14 or 15.
22. A process for producing a mutant pro-neurotrophin for use in intracellular processing of a corresponding growth factor having improved secretion efficiency as compared to wild-type growth factor, the process comprising (a) synthesis of the mutant pro-neurotrophin encoding polynucleotide, wherein the polynucleotide differs in nucleotide sequence from wild-type by replacement of the codon encoding a target asparagine residue, at a position 8 amino acids upstream from the site of cleavage for the corresponding growth factor, with a substitution codon encoding a basic residue; and (b) causing the synthetic polynucleotide to express the pro-neurotrophin.
23. The process according to claim 22, wherein the polynucleotide of claims 11 or 14 is produced by step (a).
24. A process for producing a mutant pro-neurotrophin for use in intracellular processing of a corresponding growth factor having improved secretion efficiency as compared to wild-type growth factor, the process comprising (a) synthesis of the mutant pro-neurotrophin encoding polynucleotide, wherein the polynucleotide differs in nucleotide sequence from wild-type by replacement of the codon encoding a target asparagine residue, at a position 4 amino acids upstream from the site of cleavage for the corresponding growth factor, with a substitution codon encoding a basic residue; and (b) causing the synthetic polynucleotide to express the pro-neurotrophin.
25. The process according to claim 22, wherein the polynucleotide of claim 15 is produced by step (a).
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A moving image display device that sequentially displays frame images, each consisting of multiple pixels, for video display, said moving image display device comprising:
an input unit that inputs a moving image of multiple frame images at a preset frame rate;
a read-out unit that reads out a first frame image and a subsequent second frame image, which is to be displayed immediately after the first frame image, from the input moving image;
a mixing rate specification unit that specifies parameters representing mixing rates of the first frame image and the second frame image for synthesis;
a synthesis unit that extracts pixels from the first frame image and from the second frame image in a complementary manner according to the specified parameters and combines the extracted pixels to generate at least one intermediate frame image; and
a display unit that displays the generated at least one intermediate frame image after the first frame image and before the second frame image in the process of displaying the moving image.
2. A moving image display device in accordance with claim 1, wherein said mixing rate specification unit sets a first pixel rate factor of not less than 0 and of less than 1 to be applied to extraction of pixels from the first frame image and a second pixel rate factor of not less than 0 and of less than 1 to be applied to extraction of pixels from the second frame image, as the parameters.
3. A moving image display device in accordance with claim 2, wherein the first pixel rate factor and the second pixel rate factor set by said mixing rate specification unit are an identical value.
4. A moving image display device in accordance with claim 2, wherein the first pixel rate factor set by said mixing rate specification unit is greater than the second pixel rate factor set by said mixing rate specification unit.
5. A moving image display device in accordance with claim 2, wherein the first pixel rate factor set by said mixing rate specification unit is smaller than the second pixel rate factor set by said mixing rate specification unit.
6. A moving image display device in accordance with claim 2, said moving image display device further comprising:
a moving vector volume detection unit that computes a moving vector volume of an image of a moving body included in the first frame image and the second frame image,
wherein said mixing rate specification unit sets the first pixel rate factor and the second pixel rate factor corresponding to the computed moving vector volume.
7. A moving image display device in accordance with claim 6, wherein said mixing rate specification unit refers to a table, which is provided in advance to define a relation between the first pixel rate factor and the second pixel rate factor, to set the first pixel rate factor and the second pixel rate factor.
8. A moving image display device in accordance with claim 2, said moving image display device further comprising:
a luminance variation computation unit that computes a variation in luminance between the first frame image and the second frame image,
wherein said mixing rate specification unit sets the first pixel rate factor and the second pixel rate factor corresponding to the computed variation in luminance.
9. A moving image display device in accordance with claim 2, wherein said mixing rate specification unit sets the first pixel rate factor and the second pixel rate factor to be applied to generation of each intermediate frame image, based on a total number of intermediate frame images generated by said synthesis unit.
10. A moving image display device in accordance with claim 9, wherein said synthesis unit generates at least two intermediate frame images, and
said mixing rate specification unit sets the first pixel rate factor to be greater than the second pixel rate factor for one of the at least two intermediate frame images displayed closer to the first frame image, while setting the first pixel rate factor to be smaller than the second pixel rate factor for one of the at least two intermediate frame images displayed closer to the second frame image.
11. A moving image display device in accordance with claim 9, wherein said mixing rate specification unit provides a first function of gradually increasing from 0 to 1 in a preset range and a second function of gradually decreasing from 1 to 0 in the preset range, divides the preset range by a number of intermediate frame images to be generated, and sets the first pixel rate factor and the second pixel rate factor according to values of the first function and the second function at each divisional point.
12. A moving image display device in accordance with claim 11, wherein the first function and the second function provided by said mixing rate specification unit are sine functions varying between a minimum and a maximum.
13. A moving image display device in accordance with claim 1, wherein a processing unit of the read-out process of the first frame image and the second frame image by said read-out unit and a processing unit of said synthesis unit are any one of a frame, a line, a pixel, and a scanning line in the respective frame images.
14. A moving image display device in accordance with claim 1, wherein said display unit displays the multiple frame images and the generated intermediate frame images at a multiplication of the frame rate corresponding to the number of the generated intermediate frame images.
15. A moving image display device in accordance with claim 1, wherein said synthesis unit generates at least two intermediate frame images, and
said display unit displays a predetermined mask image of low luminance, instead of one selected intermediate frame image of the at least two intermediate frame images, at timings of displaying the selected intermediate frame image.
16. A moving image display device in accordance with claim 2, wherein said synthesis unit generates at least two intermediate frame images, and
said mixing rate specification unit sets a sum of the first pixel rate factor and the second pixel rate factor to be less than 1 and applies the setting to one selected intermediate frame image of the at least two intermediate frame images generated by said synthesis unit.
17. A moving image display method that sequentially displays frame images, each consisting of multiple pixels, for video display, said moving image display method comprising the steps of
inputting a moving image of multiple frame images at a preset frame rate;
reading out a first frame image and a subsequent second frame image, which is to be displayed immediately after the first frame image, from the input moving image;
specifying parameters representing mixing rates of the first frame image and the second frame image for synthesis;
extracting pixels from the first frame image and from the second frame image in a complementary manner according to the specified parameters and combining the extracted pixels to generate at least one intermediate frame image; and
displaying the generated at least one intermediate frame image after the first frame image and before the second frame image in the process of displaying the moving image.
18. A computer program product that causes a computer to sequentially display frame images, each consisting of multiple pixels, for video display,
said computer program product comprising a computer program and a recording medium for recording said computer program therein,
said computer program comprising:
a first program code of inputting a moving image of multiple frame images at a preset frame rate;
a second program code of reading out a first frame image and a subsequent second frame image, which is to be displayed immediately after the first frame image, from the input moving image;
a third program code of specifying parameters representing mixing rates of the first frame image and the second frame image for synthesis;
a fourth program code of extracting pixels from the first frame image and from the second frame image in a complementary manner according to the specified parameters and combining the extracted pixels to generate at least one intermediate frame image; and
a fifth program code of displaying the generated at least one intermediate frame image after the first frame image and before the second frame image in the process of displaying the moving image.