[Ultrastructural study of lens in rat hereditary cataract by quick-freezing and deep-etching]

The cytoskeleton of lens fiber cells in rats with hereditary cataract (ICR/f) was studied by quick-freezing and deep-etching. Two kinds of filamentous structure with diameters of 5 and 10 approximately 15 nm were observed in the cortical fiber cells. They showed meshwork structures which were buried in globular particles. These filamentous structures were mostly absent in the nucleus fiber cells, but aggregated and fused globular particles with diameters of 10 approximately 20 nm were observed. Small cavities were sometimes observed in their cytoplasm. Between lens fiber cells, many globular structures were also seen. These changes might represent the degeneration of the lens fiber cells in cataract lenses.

Synthesis and aromatase-inhibitory activity of imidazolyl-1,3,5-triazine derivatives

Triamino-substituted 1,3,5-triazine derivatives were synthesized and tested for inhibitory activities against the aromatase of human placental microsomes and the cytochrome P450 side chain cleavage of cholesterol (P450SCC) of pig adrenal mitochondria. The compounds having imidazolyl and tertiary amino groups as substituents in the 1,3,5-triazine ring showed significant aromatase-inhibitory activity. Among them, compounds 17, 23, 26, 27 and 28 were more active than the reference compound, CGS 16949A. The inhibitory activities of these compounds against P450SCC were much weaker than their aromatase-inhibitory activities. These compounds may be regarded as selective aromatase inhibitors.

The pleiotropic effect of the GTS1 gene product on heat tolerance, sporulation and the life span of Saccharomyces cerevisiae

We investigated whether or not the potential clock gene, GTS1, of the yeast Saccharomyces cerevisiae, shows pleiotropic effects on the yeast cellular processes. We tested the efect of the Gts1 protein on heat tolerance, sporulation and life-span, by characterizing the phenotypes of transformants with different copy numbers of the gene. We found that the Gts1 protein affects the capacity of heat tolerance in the stationary phase and the speed leading to sporulation in a gene-dose dependent manner, and that both inactivation and overexpression of the gene shortened the life-span of yeast. These results supported the notion that GTS1 affects the biological clock of the yeast S. cerevisiae, although this cannot be definitively concluded because the strain cannot be synchronized with circadian or ultradian rhythms.

Two year clinical study of a soft acrylic intraocular lens

PURPOSE

To assess the efficacy and safety of a soft acrylic intraocular lens (IOL) in small incision cataract surgery.

METHODS

Sixty-four eyes of 64 patients (mean age 71.0 +/- 7.7 [SD] years) who had phacoemulsification and implantation of a soft acrylic IOL were followed for 2 years.

RESULTS

At day 1, 96.9% of patients had corrected visual acuity of 20/40 or better, and 50.0% had 20/20 or better. At 2 years postoperatively, 100% had 20/40 or better, and 86.3% had 20/20. Surgically induced keratometric cylinder remained quite stable throughout the 2 year follow-up period, with axis-based astigmatism of +/- 0.3 diopters. Flare intensity measured with the laser flare-cell meter was less than that with other type of IOLs measured, including poly(methyl methacrylate) and silicone. Neodymium:YAG laser capsulotomy was performed in seven cases (11.1%). without causing damage to the optic. No other postoperative complications were encountered.

CONCLUSION

Soft acrylic IOLs have clinically apparent advantages in small incision cataract surgery.

[Ultrastructural study of lens fiber cells by quick-freezing and deep-etching]

The ultrastructure of lens fiber cytoskeleton was studied by quick-freezing and deep-etching. Lenses of 5 Wistar male rats were divided into lens cortex and lens nucleus. Filamentous structures were clearly observed in the cortical fiber cells, which had diameters in 10 approximately 15 nm or about 5 nm. They showed a meshwork structure. On the other hand, the filamentous structures showed a linear, dense, and laminar pattern in the nuclear fiber cells. These ultrastructural changes of cytoskeletons may be related to the elongation and differentiation of lens fiber cells and may be important for maintaining transparency of the lens.

[An intraocular lens power calculation for high myopia]

The accuracy of intraocular lens power calculation formulas for the axial high myopia were examined, especially regarding the point of the predictive refraction. We examined 170 eyes with axial lengths of 27 mm or longer, with postoperative visual acuity of 0.5 or more, and postoperative astigmatism of less than +/- 2D. Five formulas were tested for accuracy in predicting postoperative refraction. They were the L-SRK, SRK, SRK II, SRK/T, and Binkhorst formulas. The SRK formula tended to predict less myopia than the actual postoperative refraction. The SRK II and Binkhorst formulas predicted more myopia than the actual postoperative refraction. The best results were produced by the L-SRK and SRK/T formulas. The accuracy of the L-SRK formula predictions were measured for each of the four myopic levels. The same was done for the SRK/T formula. For both formulas, there was no statistically significant difference in accuracy of prediction for the four myopic categories. The two formulas are considered to be useful for high myopic cases.

Preferred postoperative refraction after cataract surgery for high myopia

Eighty-four patients (121 eyes) with high myopia who had cataract surgery and intraocular lens implantation completed a survey on preferred postoperative refraction. Forty-two percent of the sample reported that they were accustomed to removing their glasses to read a newspaper or book. These respondents were fitted with soft contact lenses and their refraction changed to 0 D, -3.00 D, and -5.00 D. Of the patients whose best corrected postoperative visual acuity was 20/40 or better (n = 63), 48% preferred the -3.00 D correction; 38%, the 0 D correction; and 14%, -5.00 D. Of those with a best corrected postoperative visual acuity worse than 20/200 (n = 8), 80% preferred the -5.00 D refraction, which allowed them to read close up. Most patients with phakic eyes and good visual acuity (n = 13) preferred the 0 D and -3.00 D corrections. Our results indicate that in patients with high myopia, it is important to take patient preference into account when selecting postoperative refraction.

[The retinal image of three multifocal intraocular lenses through an eye model]

Retinal images produced by two types of multifocal intraocular lenses (IOLs) were studied using an eye model. One of them was a refractive IOL with five zones, and the other was a diffractive lens. The IOLs were inserted into an eye model with a pupil diameter of 3 mm. The retinal plane of the eye model was observed microscopically. When the section of the IOL used for far vision was in focus, the retinal image of the refractive IOL was almost the same as that of the monofocal IOL, which was better than that of the diffractive IOL. When the near vision section of the IOL was in focus, the retinal image of the diffractive IOL had almost the same quality as the far section. The light rings produced when the multifocal IOLs were illuminated by a glare source were also examined. They showed that the diffractive IOL was stronger than the refractive IOL, but the monofocal was the smallest of the three.

The GTS1 gene, which contains a Gly-Thr repeat, affects the timing of budding and cell size of the yeast Saccharomyces cerevisiae

A gene with an open reading frame encoding a protein of 417 amino acid residues with a Gly-Thr repeat was isolated from the yeast Saccharomyces cerevisiae by using synthetic oligonucleotides encoding three Gly-Thr dimers as probes. The deduced amino acid sequence showed partial homology to the clock-affecting gene, per, of Drosophila melanogaster in the regions including the GT repeat. The function of the gene, named GTS1, was examined by characterizing the phenotypes of transformants with different copy numbers of the GTS1 gene produced either by inactivating the GTS1 gene by gene disruption (TM delta gts1) or by transformation with multicopy plasmid pPER119 (TMpGTS1). They grew at similar rates during the exponential growth phase, but the lag phases were shorter for TM delta gts1 and longer for TMpGTS1 cells than that for the wild type. Analyses of their cell cycle parameters using synchronized cells revealed that the unbudding period changed as a function of gene dosage; that is, the periods of TM delta gts1 and TMpGTS1 were about 20% shorter and longer, respectively, than that of the wild-type. Another significant change in the transformants was detected in the distribution of the cell size. The mean cell volume of the TM delta gts1 cells in the unbudded period (single cells) was 27% smaller than that of single wild-type cells, whereas that of single TMpGTS1 cells was 48% larger. Furthermore, in the temperature-sensitive cdc4 mutant, the GTS1 gene affected the timing of budding at the restrictive temperature. Thus, the GTS1 gene product appears to modulate the timing of budding to obtain an appropriate cell size independent of the DNA replication cycle.

Comparative study of intraocular lens implantation through 3.2- and 5.5-mm incisions

PURPOSE

To prospectively and comprehensively compare the clinical results of two small-incision cataract surgery procedures, silicone intraocular lens (refractive index of 1.46) implantation through a 3.2-mm incision and polymethylmethacrylate intraocular lens implantation through a 5.5-mm incision.

METHODS

Two hundred eyes with cataract randomly were assigned to either procedure. Except for incision size, identical surgical methods were used in every case. Data on uncorrected and corrected visual acuity, keratometry, corneal topography, flare-cell measurement, fluorophotometry, specular microscopy, glare disability measurement, and photographic examination of intraocular lens decentration were analyzed up to 6 months after surgery.

RESULTS

Eyes in the 3.2-mm incision group displayed significantly better uncorrected and corrected visual acuity in the early postoperative period, lower aqueous flare intensity and cell counts immediately after surgery, less operatively induced astigmatism throughout the study period, and less corneal topographic changes taken 3 months after surgery. No significant between-group differences were noted for other parameters. Complications in the two groups were few and comparable.

CONCLUSION

Both procedures of small-incision cataract surgery offered satisfactory clinical results, but 3.2-mm incision cataract surgery allowed significantly earlier recovery of visual function and better preservation of corneal shape.

[Small incision cataract surgery-silicone intraocular lens vs polymethylmethacrylate intraocular lens]

We compared the postsurgical results of two small incision cataract surgery procedures: silicone intraocular lens implantation through a 3.2 mm incision and polymethylmethacrylate intraocular lens implantation through a 5.5 mm incision. One hundred fifty eyes of 124 patients were randomly assigned to either procedure, and the patients underwent phacoemulsification and intraocular lens implantation without sutures or scleral cautery. Identical surgical techniques were employed in each case except for the size of the incision. Patients in the 3.2 mm incision group showed: (1) better uncorrected and corrected visual acuity in the early postoperative period, (2) lower aqueous flare intensity immediately after surgery, (3) less operatively induced corneal astigmatism throughout the study period up to 3 months after surgery, and (4) less corneal topographic change, i.e., less corneal flattening, 3 months after surgery. There were no significant differences between groups in the corneal endothelial cell loss, blood-aqueous barrier permeability measured by fluorophotometry, or postoperative complications. It was concluded that both procedures offer highly satisfactory clinical results, but that the 3.2 mm incision surgery allows a significantly earlier recovery of visual function and less surgery-induced corneal astigmatism.

Experimental study of small intraocular lenses using an eye model

Contrast and glare tests were performed on small intraocular lenses (IOLs) using a new eye model, which was based on and about the same size as the Gullstrand eye model. Lenses with a small optic diameter were inserted and retinal images were observed under the operating microscope. Contrast and glare disability tests were done using the MCT-8000 contrast tester and the Miller-Nadler glare tester. No effect on contrast sensitivity attributable to glare was observed, but under severe glare light conditions a faint reflection around the circumference of the optic was found. Questionnaires from patients implanted with small optic IOLs confirmed that this phenomenon was similar to their symptoms.

A new endoscope for ophthalmic microsurgery

We present an endoscope designed for ophthalmic microsurgery. The handpiece contains a charge-coupled device, a solid-state imager (250,000 pixels), and a probe (either 0.89 or 1.5 mm in diameter), including the light guide. The light source is a halogen lamp. The clear views the instrument provides of the ciliary sulcus and ciliary body behind the iris make it useful in secondary posterior chamber intraocular lens implantation using the ciliary sulcus suturing technique, and in endolaser photocoagulation of the ciliary body in end-stage glaucoma. It also is useful in performing vitrectomy in cases in which visualization is difficult because of corneal opacification or fluid-gas exchange.

Modified SRK formula for axial myopia (24.5 mm < or = axial length < 27.0 mm)

When used for eyes with greater than average axial length (AXL), the SRK formula has been reported to have a tendency to yield more myopic refractions than those predicted. To further evaluate such findings, we studied 609 eyes with AXLs between 24.5 and 27.0 mm. Comparing the predicted with the actual refractions and calculating the range of errors, we found that the postoperative refractions were more myopic than predicted. Then, based on our evaluation of the relationship between the postoperative refractions and the powers of the implanted intraocular lenses (IOLs), we devised the following formula: R = 0.8 x (P - I) + 0.57 (P < .01) in which R = the postoperative refraction; P = the emmetropic IOL power; and I = the actual IOL power. Testing this modified SRK formula in 55 additional eyes, we found that the predicted postoperative refractions it yielded were more accurate than those calculated using five earlier formulas.

Long-term study of children with implanted intraocular lenses

We studied children between five and 15 years of age who were implanted with intraocular lenses (IOLs). The subjects comprised eight cases of traumatic cataract, 11 of congenital cataract, and six of steroid cataract. The follow-up ranged from four months to nine and one half years. Twenty of the eyes studied achieved a postoperative visual acuity of equal to or better than 20/40. Binocular function was retained in most cases. Postoperative complications included seven cases of posterior iris synechia, three of iris capture, one of transitory elevated intraocular pressure, and one of cystoid macular edema. Corneal endothelial studies were normal in the eyes in which posterior chamber IOLs were implanted.

Sulcus fixation of posterior chamber lenses by transscleral sutures

Sulcus fixation of posterior chamber lenses by transscleral sutures was performed in 23 cases. We used new techniques to be sure that the sulcus was pierced accurately and the suture was placed in the posterior chamber instead of the ruptured capsule. This paper describes these techniques and the clinical results of 23 cases.

Antitumor activity of MST-16, a novel derivative of bis(2,6-dioxopiperazine), in murine tumor models

We studied the antitumor activity of newly synthesized bis(1-acyloxymethyl) derivatives of 4,4'-(1,2-ethanediyl)bis(2,6-piperazinedione) using i.p.-i.p. models of P388 leukemia and B16 myeloma. As a result, we found 4,4'-(1,2-ethanediyl)bis(1-isobutoxycarbonyloxymethyl-2,6-piperazi nedione) (MST-16) to possess considerable therapeutic activity. MST-16 showed not only marked life-prolonging effects in both P388 leukemia- and B16 melanoma-bearing mice but also a greater therapeutic ratio than did its parent compounds, ICRF-154 and ICRF-159. Further studies revealed that MST-16 has considerable therapeutic activity against a number of other tumors such as ascitic forms of L1210 leukemia, colon 26 adenocarcinoma, and MH-134 hepatoma and solid forms of B16 melanoma, Lewis lung carcinoma, colon 38 adenocarcinoma, and M5076 fibrosarcoma. These results suggest that MST-16 is very promising as an antitumor agent.

Synthesis and antitumor properties of N1-acyloxymethyl derivatives of bis(2,6-dioxopiperazines)

Many N1-acyloxymethyl derivatives VI of bis(2,6-dioxopiperazine) I, ICRF-154, were prepared and tested for antitumor activity. The treatment of I with formaldehyde gave a crystalline bis(N1-hydroxymethyl) derivative VII, which was acylated under various conditions to give bis(N1-acyloxymethyl) derivatives VI. Antitumor activity of VI against P388 leukemia in mice was studied. Several bis(N1-acyloxymethyl) compounds such as phenylacetyloxymethyl VI-6, methoxycarbonyloxymethyl VI-41, isobutoxycarbonyloxymethyl VI-44, and furancarboxymethyl VI-38 compounds were found to have potent antitumor activities. On the other hand, water-soluble esters having an amine or a carboxylic acid function in their acyl groups showed rather reduced activity. These bis(N1-acyloxymethyl) derivatives VI were presumably hydrolyzed into the parent bis(2,6-dioxopiperazine) I by nonspecific esterase in the body to exhibit their antitumor activity.

[Results of fetoscopic examinations at our hospital]

From 1983 to 1985, antenatal diagnosis by fetoscopy under ultrasound guidance has been performed at our institute for 17 pregnant women between 15 and 34 weeks of gestation. Indications for fetoscopy were visualization of the fetus, placenta, and amniotic membrane for morphological anomaly and fetal blood sampling for coagulation disorder. The diagnosis, made by visual observation of the fetus, blood coagulation tests, and karyotyping revealed 12 normal fetuses and 5 abnormal fetuses (one having chromosome abnormality, one amniotic band syndrome, one cephalothracopagus, one Beckwith-Wiedemann syndrome, and one sacral tumor). Courses of pregnancy following fetoscopy resulted in four normal full-term deliveries, six premature deliveries due to four hydramnions and two spontaneous ruptures of the membrane more than 14 weeks after fetoscopy. Three other pregnancies were interrupted due to intrauterine fetal death 11 weeks after fetoscopy in one case and to therapeutic abortion for maternal complications such as toxemia of pregnancy in two cases. The outcome of one case was unknown because the mother had moved away. The other pregnancy is still under observation at the third trimester. Although no complications in the fetuses were seen following fetoscopy, complications in the mothers included two cases of genital bleeding, one case of amniotic fluid leakage, and one cases of abruption of the fetal membrane. Symptoms in all four cases disappeared during several days of bed rest. These results demonstrate the importance of fetoscopy in prenatal diagnosis.

Abnormally large placenta associated with Beckwith-Wiedemann syndrome

A 37-year-old G1-P1 was diagnosed by ultrasonography at 26 weeks of gestation as having an abnormally large placenta with hemangiomas and a fetus associated with exomphalos. Placental protein 5 levels were relatively high in placental protein levels in maternal serum. The infant, delivered by cesarean section at 34 weeks, had the typical clinical features associated with Beckwith-Wiedemann syndrome. The abnormally large placenta weighed 1,492 g, measured 25 X 25 X 5.1 cm, and featured multiple hemangiomas. Microscopic placental features included edematous villi, increased fibrin deposition, intervillous thrombi, and multiple angiomatous and cellular chorangiomas.

Study on the contraction and oxygen consumption induced by high K, Na-deficient solution in the urinary bladder and gall bladder of guinea-pig

In urinary bladder and gall bladder of guinea-pig, the application of hyperosmotic 65.4 mM K solution induced a tonic contraction and increased the rate of oxygen consumption two or three times. The increased O2 consumption maintained steady level during 120 min. In isosmotic 154 mM K, Na-deficient solution, the tonic contraction gradually decreased and oxygen consumption also showed a transient increase followed by a small one. In the urinary bladder, the addition of pyruvic acid completely prevented the decline of the tonic contraction by iso-154K solution at 120 min, but this addition partially prevented it in the gall bladder. Hyperosmotic application of sucrose partially prevented it in the urinary bladder, but completely recovered it in the gall bladder. When NaCl was applied to iso-154K solution, the decrease of tonic contraction was prevented by half in both the muscles. The application of pyruvic acid and NaCl prevented the reduction of oxygen consumption by iso-154K solution in the urinary bladder, but in the gall bladder, this had little effect. There was a close correlation (r = 0.950) between the muscle tension and the rate of oxygen consumption in the urinary bladder at 120 min under various conditions. In the gall bladder, a correlation (r = 0.875) was also found between both when the results by hyperosmotic addition of NaCl and sucrose were omitted. In the urinary bladder, tension cost, a ratio of O2 consumption rate (mumol O2/g/min) to developed tension (kg force/cm2), was large (0.206) and similar to that of taenia coli; and that of gall bladder was small (0.130) and almost similar to that of vascular smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparative study on the contraction induced by high K/Na deficient solution in the trachea, gall bladder and urinary bladder in guinea-pig

In the present paper, a comparative study of high K solution was carried out on the mechanical response, wet and dry weights of tissue, and extracellular space of 14C-sorbitol in the trachea, gall bladder, and urinary bladder of guinea-pig. Hyperosmotic addition of KCl to the physiological solution produced a sustained contraction, while isosmotic substitution of K for Na in the physiological solution induced a contraction followed by a small sustained one in the trachea, gall bladder or urinary bladder. At 120 min after application of the substituted KCl, Na deficient solution, it increased cell water content in the smooth muscle cells of the trachea or gall bladder, but did not change that in the urinary bladder. Both the inhibition of contraction and the swelling in the trachea or gall bladder were prevented by the hyperosmotic application of sucrose or NaCl. The substitution for NaCl with the K salts with more permeable anions (I- greater than NO3- greater than Cl-) produced a greater inhibition of contraction in the trachea and gall bladder. Although the impermeable anion C2H5CO2- did not inhibit the contraction in the trachea, this anion partially inhibited it in the gall bladder. On the other hand, the inhibition of contraction in the urinary bladder was prevented by addition of pyruvate, oxalacetate or NaCl.(ABSTRACT TRUNCATED AT 250 WORDS)

[Immuno-electron microscopy study of Toxoplasma gondii. II. Study of IgM antibodies]

This paper deals with an immunoelectron microscopic study of the localization of IgM vector on the membrane of Toxoplasma gondii using the antibody at the early period of infection. The primary antibody was IgM antibody obtained from rabbit's serum 11 days after the infection of Beverley strain of Toxoplasma gondii from which IgG was absorbed by protein A containing staphylococcus. Ferritine-labeled antibody against rabbit's IgM was used as the secondary antibody. The surface of normal tachyzoites is smooth with two layered plasma membrane. The outer layer shows a three-layer structure which is not found in the inner membrane. The inner membrane is discontinuous with partially lost portion at the head of the tachyzoites. Structure within plasma include conoid toxonems, dark staining vacuoles and nucleus. By reacting with the ferritin-labeled antibody, ferritin particles were found on all over the circumference of the tachyzoites depositing on the surface of the outer plasma membrane, but few on the inner plasma membrane and organelles. It implies that IgM receptors are localized on the membrane surface similarly with our preceding report.