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Biomedical subjects

Y Kitazawa

Publications and source records attributed to Y Kitazawa.

At least 181 records · Page 10Linked to original sources
PubMed1989

[Computerized digital image analysis of optic nerve heads with a three-dimensional image analyzer, IMAGEnet and a comparison with the Optic Nerve Head Analyzer].

Computerized digital image analysis of the optic nerve heads of 17 eyes with various sizes of optic disc cupping was performed using two kinds of three dimensional image analyzers, the IMAGEnet and the Optic Nerve Head Analyzer (ONHA). Intraphotographic error variances of measurements with both instruments were evaluated by measuring each image of the optic discs twice. The mean coefficient of variation (CV) with the IMAGEnet for the vertical cup/disc ratio, the horizontal cup/disc ratio, the cup volume, the rim area, and the rim area/disc area ratio were 3.75%, 3.03%, 7.89%, 2.55% and 1.36%, respectively. With the ONHA, the mean CV for the total cup/disc ratio, the cup volume, the rim area, and the rim area/disc area ratio were 0.82%, 0.21%, 2.39%, and 1.56%, respectively. The value of the cup/disc ratio and the cup volume obtained by the IMAGEnet was smaller than those by the ONHA (p greater than 0.1). Conversely, the rim area and rim area/disc area ratio measured by the IMAGEnet were statistically significantly larger than those by the ONHA (p = 0.01). Statistically significantly positive correlation was demonstrated for measurements made by both instruments in all disc parameters (p less than 0.01). These results seem to indicate the high reliability of the two instruments, however, further investigation is needed for the evaluation of the accuracy of measurements.

Glaucoma↗
PubMed1989

Use of apraclonidine to reduce acute intraocular pressure rise following Q-switched Nd:YAG laser iridotomy.

We evaluated the effectiveness of topical apraclonidine (ALO 2145, p-amino clonidine hydrochloride) in suppressing an acute postoperative intraocular pressure (IOP) rise following Nd:YAG laser iridotomy. Fifty-eight eyes (45 patients) with chronic primary angle-closure glaucoma underwent Q-switched Nd:YAG laser iridotomy. Twenty-nine eyes followed prospectively underwent Nd:YAG laser iridotomy following the topical administration of 0.5% apraclonidine prior to and immediately following the procedure. A retrospective control group of 29 eyes underwent Nd:YAG laser iridotomy without topical apraclonidine. Only one eye (3.4%) treated with apraclonidine experienced an IOP rise greater than 10 mm Hg over baseline, while five among 29 untreated eyes (17.2%) developed an IOP rise greater than 10 mm Hg.

Aged↗
PubMed1988

The primary structure of the leu1+ gene of Schizosaccharomyces pombe.

A DNA fragment which carries the leu1 gene encoding beta-isopropylmalate dehydrogenase in Schizosaccharomyces pombe has been isolated by complementation of an E. coli leuB mutation. This 1.5 kb DNA fragment complements not only the S. pombe leu1 mutation, but also the S. cerevisiae leu2 mutation. The nucleotide sequence of the essential part of the leu1 gene and its flanking regions was determined. This sequence contains an open reading frame of 371 codons, from which a protein having a Mr = 39,732 can be predicted. The deduced amino acid sequence and its codon usage were compared with those of the S. cerevisiae LEU2 protein. The cloned DNA will be a useful marker when transforming S. pombe.

3-Isopropylmalate Dehydrogenase↗
PubMed1988

A case of ruptured duodenal varices and review of the literature.

The incidence of duodenal varices is exceedingly rare. A case of bleeding duodenal varices located in the third portion of the duodenum, secondary to idiopathic portal hypertension, which was successfully treated by surgery, is presented herein. Diagnosis was suspected at superior mesenteric angiography and was subsequently confirmed by endoscopy. A review of the literature reveals only 105 such cases in the world. While the duodenal bulb is the most common site of duodenal varices, the second portion of the duodenum appears to be the next most common site but duodenal varices in the other portions are extremely rare. From all of the possible causes of duodenal varices, liver cirrhosis remains the predominant etiological factor in 31 cases.

Duodenum↗
PubMed1988

Further studies on the resolution of human mercapt- and nonmercaptalbumin and on human serum albumin in the elderly by high-performance liquid chromatography.

High-performance liquid chromatographic (HPLC) analysis of human serum albumin (HSA) on Asahipak GS-520 showed at least two peaks, the principal component corresponding to human mercaptalbumin (HMA) and the secondary one to nonmercaptalbumin (HNA). HPLC analysis of HSA on Asahipak ES-520 N showed three peaks, the principal component corresponding to HMA, the secondary one to HNA having mixed disulfide with cysteine or glutathione and the tertiary one to HNA oxidized higher than mixed disulfide. Two kinds of rapid HPLC for the resolution of HSA into HMA and HNA were developed by the present authors. Using these HPLC, the present authors found a significant decrease in the fraction of HMA in the elderly.

Aged↗
PubMed1988

On age-related norms of the visual field.

We prospectively studied the influence of age on visual fields obtained from 108 normal subjects (147 eyes) by using the Humphrey Field Analyzer (Program 30-2). Differential light sensitivity remained constant irrespective of age until the age of 35 to 44 years in the vast majority of test locations and then decreased linearly with age. The rate of linear decline differed at different test locations and failed to correlate with the eccentricity from the fixation, although its variance increased with the eccentricity. The mean sensitivity and the volume of the visual field were also constant until the age of 37.4 and 37.6 years, respectively.

Adolescent↗
PubMed1987

5-Fluorouracil for trabeculectomy in glaucoma.

The effect of 5-fluorouracil (5-FU) subconjunctival injection on the bleb formation and intraocular pressure (IOP) following trabeculectomy was studied in 18 glaucoma patients (20 eyes) with poor surgical prognosis. The results were analyzed by means of life tables and compared with those of 24 glaucoma eyes that had undergone trabeculectomy without postoperative administration of 5-FU after a previous repeat trabeculectomy that had failed. The surgical techniques and postoperative care were virtually identical between the eyes treated with 5-FU and eyes that had undergone repeat trabeculectomy, except that the latter group did not receive 5-FU postoperatively. At the end of 18-month follow-up, the success probability was 68.2% in the 5-FU treated eyes, and it was already as low as 10% in the nontreated eyes at the end of the 14-month follow-up. The difference was statistically highly significant (P less than 0.001). Postoperative, subconjunctival injection of 5-FU appears to improve the prognosis following trabeculectomy in patients with a poor surgical prognosis.

Cicatrix↗
PubMed1986

Optic disc hemorrhage in low-tension glaucoma.

The prevalence of optic disc hemorrhage (DH) was determined in groups consisting of 192 primary open-angle glaucoma, 113 primary angle-closure glaucoma, 78 low-tension glaucoma, and 473 normal patients. The DH was mot prevalent (20.5%) among low tension glaucoma patients (chi 2; P less than 0.001). The epidemiological features of DH were studied in 58 low-tension glaucoma patients by examining them every one to four weeks from 6 to 32 months. All the DHs but one took place within a seven-month follow-up and the incidence of DH varies from 0 to 10% during the 32-month follow-up period. The overall incidence of DH was 24.8% during that period of time. Recurrences were seen in 64% of the eyes and 92% of these occurred within 28 weeks following the previous hemorrhages. Ninety-two percent of all DHs were present for at least four weeks. Low-tension glaucoma eyes seem to consist of two different groups; one which develops recurrent DH and one which is very unlikely to bleed through its entire course.

Eye Diseases↗