Molecular cloning, water channel activity and tissue specific expression of two isoforms of radish vacuolar aquaporin.

A major membrane intrinsic protein (VM23) in vacuoles of radish (Raphanus) tap root was investigated. The cDNAs for two isoforms of VM23, gamma- and delta-VM23, encode polypeptides of 253 and 248 amino acids, respectively. gamma- and delta-VM23 correspond to the gamma- and delta-TIP (tonoplast intrinsic protein) of Arabidopsis. The deduced amino acid sequences of the two VM23 isoforms were 60% identical. The amino-terminal sequence of gamma-VM23 showed agreement with the direct sequence of the purified VM23, suggesting that gamma-VM23 is the most abundant molecule among the VM23 isoforms. When mRNAs of gamma- and delta-VM23 were injected into Xenopus oocytes, the osmotic water permeability of oocytes increased 6-fold (60 to 200 microns s-1) of the control oocytes. The transcripts of both isoforms were detected in a high level in growing hypocotyls and young leaves, but delta-VM23 was not detected in seedling roots. Light illumination enhanced the transcription of two genes of VM23 in cotyledons and roots but suppressed their expression in hypocotyls the growth of which was inhibited by light. These findings suggest that the expression of VM23 is tightly related to cell elongation.

Tumor cell growth is inhibited by suppressing metallothionein-I synthesis.

The effect of metallothionein (MT)-I antisense oligodeoxynucleotide (ODN) on the growth of three kinds of tumor cells was studied, since MTs may be involved in cell growth. When MT-I antisense ODN was added to leukemia P388 cells, cell growth was inhibited in a manner dependent on the dose and incubation time. MT-I antisense ODN was also inhibitory for other tumor cell lines, i.e. Ehrlich carcinoma and sarcoma 180. A significant decrease in the level of MT, but not of Zn, was observed in MT-I antisense ODN-treated cells. On the other hand, control ODN did not inhibit the cell growth appreciably. These results indicate that MT-I expression may be necessary for the growth and survival of these tumor cells.

Proposal for aberration-corrected imaging spectrograph.

We propose a novel flat-field imaging spectrograph that consists of two plane gratings, four spherical mirrors, and two plane mirrors. The imaging spectrograph is designed in such a manner that the primary and the secondary principal points of the whole optical system for the horizontal direction coincide with those for the vertical direction. In a paraxial approximation, it is essentially aberration free because an entrance slit and an imaging detector are placed on the primary and the secondary principal planes, respectively. Spot diagrams obtained from ray-tracing procedures have indicated that the proposed spectrograph is superior to the conventional Czerny-Turner mounting.

[Aniseikonia of central serous chorioretinopathy].

Central serous chorioretinopathy (CRS) is one of the typical diseases that accompany micropsia. However very little is known about micropsia of CRS, because of the difficulty to measure "aniseikonia" in terms of micropsia. Aniseikonia in 65 cases of CRS was measured quantitatively by Awaya's New Aniseikonia Tests (NAT). The tests were performed at two different distances of 40 cm (visual angle: 6 degrees) and 20 cm (12 degrees) and under 4 meridians of the halfmoon on NAT, horizontal, 45 degrees, vertical and 135 degrees, respectively. The mean value of aniseikonia under each testing condition was as follows: 6 degrees horizontal -3.13%, 45 degrees -2.56%, vertical -2.13%, 135 degrees -2.57%, 12 degrees; horizontal -1.38%, 45 degrees -1.69%, vertical -1.84%, 135 degrees -1.50%. At 6 degrees aniseikonia is larger in the horizontal meridian than in the vertical with statistical significance (t-test, p less than 0.05), while at 12 degrees aniseikonia is smaller than at 6 degrees and shows no particular tendency in terms of meridian. The phenomenon observed at 6 degrees may be what is called "oriented metamorphopsia".

Three cases with light-induced retinopathy.

Three patients presented a characteristic retinopathy presumably induced by light arising from operating microscope during extracapsular cataract extraction combined with intraocular lens insertion. The operating microscope was equipped with video-recorder. Light sources were tungsten bulb. All cases were asymptomatic and an inspection at the post-operative control examination led to the detection of this type of retinopathy.