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Biomedical subjects

A Kanai

Publications and source records attributed to A Kanai.

At least 109 records · Page 6Linked to original sources
PubMed1995

[A study on the rhodopsin gene in Japanese retinitis pigmentosa--screening of mutation by restriction endonucreases and frequencies of DNA polymorphisms].

We analyzed 11 sites of the rhodopsin gene using polymerase chain reaction (PCR) amplification and restriction endonucleases in 30 unrelated Japanese patients with autosomal dominant retinitis pigmentosa (ADRP). No point mutation was found in any patient. The frequencies of the single nucleotide (nt) substitution at nt 269, nt 5145 and nt 5321 were examined in three groups, 38 unrelated patients with ADRP, 23 patients with autosomal recessive retinitis pigmentosa (ARRP), and 67 normal controls. There was no significant difference in the frequencies of substitution among these three groups. The frequencies of A269G, G5145A, and C5321A were 52%, 36%, and 5%, respectively. These values were different from those of the American population. The polymorphisms, A269G and G5145A, are useful as DNA makers for linkage analysis.

Asian People↗
PubMed1995

Effect of sodium hyaluronate ophthalmic solution on peripheral staining of rigid contact lens wearers.

We evaluated the efficacy of sodium hyaluronate ophthalmic solutions on 3 and 9 o'clock staining with rigid contact lens wearers in a double masked multicenter study involving four institutions and 43 patients. Both sodium hyaluronate (0.1%) and control ophthalmic solutions (artificial tears) without preservative were used. Patients were randomly divided into two groups. The test group received sodium hyaluronate ophthalmic solution, and the control group received artificial tears as a control ophthalmic solution. The agents were instilled six times per day for 2 weeks while patients wore contact lenses. Although subjective symptoms improved similarly in the two groups, slit lamp observation, corneal staining, and anterior segment photography demonstrated improved results in eyes having received sodium hyaluronate ophthalmic solutions. We conclude that sodium hyaluronate ophthalmic solution is effective and safe for treating 3 and 9 o'clock staining in rigid contact lens wearers.

Administration, Topical↗
PubMed1994

Acute retinal necrosis syndrome associated with herpes simplex keratitis.

BACKGROUND: Although acute retinal necrosis (ARN) syndrome is caused by a herpes group virus, association of herpetic keratitis with ARN syndrome is uncommon. A case of unilateral ARN syndrome with herpes simplex keratitis is discussed. METHODS: A 40-year-old man developed unilateral keratitis, necrotic retinitis, retinal vasculitis, vitritis, and iritis consistent with ARN syndrome 1 month after treatment for ipsilateral facial nerve palsy and auricular herpetic vesicles (Tolosa-Hunt syndrome). Impression cytologic examination of the corneal epithelial ulcer that developed concurrent with the intraocular findings and of the aqueous humor (obtained by paracentesis) was performed. RESULTS: Cells that reacted with anti-herpes simplex virus type 1 (HSV-1) antibody were detected on impression cytology, and DNA fragments corresponding to the HSV-1 DNA sequence were detected in the aqueous humor. CONCLUSION: This case shows that ARN syndrome may, on rare occasions, be associated with herpes keratitis secondary to HSV-1.

Adult↗
PubMed1994

Subthreshold stimulation of Purkinje fibers interrupts ventricular tachycardia in intact hearts. Experimental study with voltage-sensitive dyes and imaging techniques.

The effects of subthreshold stimulation (STS) delivered during right atrial pacing and ventricular tachycardia (VT) were investigated in Langendorff-perfused guinea pig hearts. The hearts were stained with a voltage-sensitive dye (RH 421) to map the propagation of optical action potentials. Sustained VT was reliably induced by 5-second trains (cycle length [CL], 25 to 50 milliseconds; duration, 0.5 to 10 milliseconds; and voltage, 2x threshold voltage) of impulses (n = 12 hearts) or a single premature beat (n = 6). The location of extrastimuli was not critical to the induction of VT, but the diameter of the heart had to be > or = 14.5 mm. During VT, heart rate increased from 200 to 600 beats per minute; action potential durations decreased from 112 to 175 milliseconds to 60 to 105 milliseconds, with no diastolic interval. Activation on the epicardium spread anisotropically, but VT decreased the "apparent" maximum conduction velocity (theta max) by 68% and altered the orientation of the major axis from beat to beat. Activation patterns and theta max measured during VT were similar to patterns recorded during direct pacing of the ventricle and indicated that Purkinje fibers no longer propelled ventricular excitation. STS (CL, 25 to 50 milliseconds; duration, 0.5 to 25 milliseconds; and voltage, 0.5x to 0.8x threshold; trains of 2.0 to 2.5 seconds) interrupted VT when applied to Purkinje fibers lining the endocardium (n = 6) but failed to interrupt VT when applied to the epicardium (n = 8). In atrial pacing, STS delivered to the endocardium increased theta max from 2.44 +/- 0.32 (mean +/- SEM) to 3.63 +/- 0.21 m/s in a local region surrounding the first activation sites (n = 4). Alternatively, VT could be terminated by reducing theta max (approximately 55%) with procainamide (10 mumol/L) (n = 6). STS terminates VT by synchronizing ventricular excitation most likely by increasing local conduction and/or improving the coupling between Purkinje and ventricular cells.

Action Potentials↗
PubMed1994

[Career stress model among working women: examining the determinants of turnover and quitting based on path analysis].

For the purpose of examining the determinants of turnover and quitting among working women, 283 working women were sampled from several private corporations in Japan. The causal relation model was named "Career Stress Model among Working Women" since it involved, among others, unique job stressors for working women. The results of path analysis showed that among women, the higher the stressors due to sex discrimination in working spaces, the higher the turnover. Further, the results showed that the lower the job commitment, the higher the quitting. However, since job commitment increases with corporate eagerness towards development of women's careers, corporate efforts to remove all elements of sex discrimination and efforts to implement policies which assist development of women's careers were considered to be important in reducing turnover and quitting among working women.

Adolescent↗
PubMed1993

DNA-binding proteins and their cis-acting sites controlling hormonal induction of a mouse beta-casein::CAT fusion protein in mammary epithelial cells.

Transcription of the mouse beta-casein (beta CAS)-encoding gene (casB) is regulated by the synergistic actions of insulin, glucocorticoid and prolactin in the mammary gland (MG). To delineate its regulatory sequence(s), we examined the hormonal inducibility of various chimeric constructs containing the promoter sequence of casB and the cat reporter gene in primary MG epithelial cells. A DNA fragment from bp -258 to +7 of casB was sufficient for the hormonal induction. Using a series of 5'- and internal deletions of the casB promoter region, at least three DNA elements were found to be necessary for full induction. These were located at bp positions -258 to -180, -154 to -136, and -98 to -62. DNase I footprinting analysis with a partially purified extract from lactating MG cells detected at least seven protected sequences, I(-242 to -219), II(-213 to -202), III(-151 to -139), IV(-125 to -110), V(-98 to -90), VI(-79 to -70) and VII(-59 to -45). Regions I/II, III and V/VI were included in the three DNA elements required for the hormonal induction, and the IV region corresponded to the MG consensus sequences of several milk protein-encoding genes. Competition gel retardation assays using nuclear extracts of lactating mouse MG revealed the presence of specific binding proteins for regions I, II, IV and VI, as well as specific protein(s) binding to both regions III and V. The binding activities of these proteins, except that associated with region IV, were increased from the virgin to lactating periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Clinical features of autosomal dominant retinitis pigmentosa with rhodopsin gene codon 17 mutation and retinal neovascularization in a Japanese patient.

A 49-year-old Japanese man had autosomal dominant retinitis pigmentosa with a point mutation in codon 17 of the rhodopsin gene, resulting in a threonine-to-methionine change, and retinal neovascularization in both eyes. Pigmentary degeneration mainly in the inferior area of the fundus, and severe loss in the upper portion of the visual field were observed. Moderately preserved rod and cone functions were demonstrated by electroretinograms. These findings differed from those of Japanese and white patients with autosomal dominant retinitis pigmentosa with a codon 347 mutation and were almost the same as those of white patients with the codon 17 mutation. Our study indicates that phenotypic similarities exist among patients with the same mutation, but of different racial backgrounds. The neovascularization in the right eye diminished over a two-year period in conjunction with the progression of retinal degeneration.

Adaptation, Ocular↗
PubMed1993

Spheroidal keratopathy associated with subepithelial corneal amyloidosis. A clinicopathologic case report and a proposed new classification for spheroidal keratopathy.

PURPOSE: An unusual case of primary spheroidal degeneration associated with subepithelial corneal amyloidosis is described clinically and histopathologically, and a new classification for spheroidal keratopathy is proposed. METHODS: The corneal button obtained by lamellar keratoplasty was examined by light and transmission electron microscopy. Amyloid deposits were evaluated further by means of the thioflavin T fluorescence technique, the potassium permanganate reaction, and immunohistochemical studies using antibodies against immunoglobulin light chains and proteins AA and AP. RESULTS: Spheroidal droplets were observed in basement membrane, Bowman's layer, and anterior stroma, and exhibited characteristic staining with Verhoeff's iron hematoxylin. Amyloid deposits were found beneath the epithelium, almost exclusively in the central area of the corneal button. The deposits showed no immunohistochemical staining with antibodies to amyloid proteins AA and AP or kappa and lambda light chains. CONCLUSIONS: The histochemical properties of the spheroidal droplets in this case were similar to those observed by other authors and suggested a sulfur-rich protein other than keratin. The combination of clinical and pathologic findings permitted the differential diagnosis of subepithelial amyloidosis and distinguished this condition from that of gelatinous drop-like dystrophy. To the authors' knowledge, this is the first description of primary spheroidal keratopathy associated with secondary subepithelial corneal amyloidosis in an eye that had not undergone previous keratoplasty.

Adult↗
PubMed1993

A multicenter study of typical retinitis pigmentosa in Japan.

A nationwide, multicenter study of typical retinitis pigmentosa was carried out in collaboration with 13 university hospitals throughout Japan. A total of 253 patients, 122 males and 131 females, with a wide range of ages (mean 48 years), were registered during a two-month period in 1989. Determination of inheritance pattern revealed 30.2% autosomal recessive cases, 15.4% autosomal dominant, 0.5% X-linked, and 48.9% simplex, indicating a relative decrease in autosomal recessive cases and a relative increase in simplex cases in recent decades. The age at onset, initial symptom, and visual functions including visual acuity, visual field and electroretinogram showed a marked interindividual variability, but statistical analysis demonstrated that visual defects progressed with increasing age and disease duration. A correlation between the phenotypic variation and the genetic type was observed. This survey of retinitis pigmentosa in Japan provides information for counseling and rehabilitation of patients and encourages basic and clinical research of this genetic disease.

Adolescent↗
PubMed1993

[Application of cyclosporin for cornea graft].

This study aimed to determine the optimal concentration rate of clinically effective Cyclosporin (CYA). Exchange penetrating keratoplasties were performed on 30 albino rabbits divided into 3 groups of ten, Groups I, II, and III, using 7 mm. trephine. In Group I 0.025% CYA drops were administered 4 times per day for 50 days and similarly 0.05% CYA drops were given in Group II. Only the solvent (alpha cyclodextrin), without any CYA, was applied to Group III, the control group, in the same manner. Suture removal and skin grafting were carried out on the 14th day after operation, as an additional means of sensitization. The 50-day post-operative rate of transparency retention was 40% for Group I, and 80% for Group II, and 20% for Group III, indicating that 0.05% CYA concentration was the most effective. In Experiment II, hetero-lamellar keratoplasties were performed on 16 albino rabbits to 8 Wistar rats, divided into Groups I and II. CYA (0.05% concentration) was applied 4 times a day for 50 days in Group I. Group II, the control group, was not treated. Both groups were followed for 100 days post operation. The 50-day post-operative rate of transparency retention of Group I was 71.4% and 12.5% for Group II. These figures also confirmed the effectiveness of 0.05% CYA. The results of our two experiments demonstrate that the application of 0.05% CYA would be most effective clinically.

Animals↗
PubMed1992

A Japanese pedigree of autosomal dominant congenital stationary night blindness with variable expressivity.

Three cases in three successive generations of one family with autosomal dominant congenital stationary night blindness are presented. Case 1, the proband, and Case 3, his grandfather had the same electroretinographic responses: nonrecordable scotopic electroretinogram (ERG), normal but slightly diminished flicker ERG, and negative-shaped single bright-flash ERG. Their dark adaptation curves were monophasic with no rod segment. However, Case 2, the proband's father, showed different ERG findings; a moderately diminished scotopic ERG, a normal flicker ERG, and a biphasic dark adaptation curve with an elevated final rod threshold. The authors believe that these differences reflect variations in the expressivity of a single gene mutation with the lowest expressivity being seen in Case 2.

Adult↗
PubMed1992

[The immunosuppressive effects of 0.025% cyclosporin eye drops in alpha cyclodextrin on rabbit corneal allografts].

We reported the ocular penetration of cyclosporin (CYA) and the immunosuppressive effect of rabbit corneal allograft using 0.025% CYA eye drops in alpha-cyclodextrin (alpha-CD). Local application using 0.025% CYA in alpha-CD showed the concentration of 4,133 ng/gr in the cornea, but no detectable levels in aqueous humor and serum. All eyes (10/10) in the CYA eye drop group remained clear for 100 days after corneal allografting. CYA eye drops halted and suppressed the corneal allograft's immune reaction when the treatment was begun early in the initial phase of rejection. These results indicate that 0.025% CYA eye drops in alpha-CD penetrate the cornea 5 to 10 times more than CYA eye drops in lipophilic vehicles. Furthermore, they are extremely effective in suppressing the immune reaction of corneal grafts.

Animals↗
PubMed1992

[An epidemiogenetic study of typical retinitis pigmentosa in Japan--a preliminary report of nationwide, multicenter study].

We performed a nationwide, multicenter study of typical retinitis pigmentosa with reference to the inheritance patterns of the disease. A total of 253 probands were registered during two months of 1989, and an analysis of the parental consanguinity of 182 probands with the method of inbreeding coefficient enabled us to estimate the relative prevalence of genetic types; autosomal recessive trait: 47.6%; autosomal dominant trait: 17.3%; sporadic cases: 34.6%. A comparison of the results with previous studies has indicated a decrease in the prevalence of the autosomal recessive trait and an increase in the sporadic cases, as would be expected from the decrease in consanguineous marriages and offsprings in the past few decades in Japan. X-linked retinitis pigmentosa was rarely identified, but precise evaluation of its frequency needs further investigation.

Adolescent↗
PubMed1992

[Molecular biological study of the rhodopsin gene in Japanese patients with autosomal dominant retinitis pigmentosa].

The author analyzed codon 347 of the rhodopsin gene using PCR (polymerase chain reaction) amplification and restriction enzymes in 19 unrelated Japanese families including 28 patients with autosomal dominant retinitis pigmentosa (ADRP). An allele of codon 347 mutation was found in a family (father and daughter). Sequence analysis shows that the mutation is from CCG to CTG. This mutation appears to be the cause of one form of ADRP, since it was also found in Japanese cases of ADRP which have a different racial background from families reported by Dryja et al.

Codon↗
PubMed1992

High frequency of mitochondrial ND4 gene mutation in Japanese pedigrees with Leber hereditary optic neuropathy.

The association of the ND4 gene mutation (mutation) at nucleotide position 11778 of mitochondrial DNA (mtDNA) was investigated in 14 definitive Japanese pedigrees with Leber hereditary optic neuropathy (LHON). The mutation was detected by SfaNI and MaeIII restriction fragment length polymorphisms of mtDNA amplified by polymerase chain reaction. All 14 LHON pedigrees exhibited the mutation, whereas 10 controls did not. The association of this mutation with LHON was revealed to be significantly higher in Japanese (91.7%) than in 27 reported Caucasian (51.9%) LHON pedigrees, implying genetic heterogeneity. In the tested 14 pedigrees, 28 cases with the mutation comprised 19 affected (17 male and 2 female) and 9 asymptomatic (all female except for one) individuals. Such a predominance of males in the incidence of LHON suggested probable participation of additional pathogenetic factor(s) in the development of optic atrophy in LHON patients.

Adolescent↗
PubMed1992

Clinical features of Japanese family with autosomal dominant retinitis pigmentosa caused by point mutation in codon 347 of rhodopsin gene.

Four members in a Japanese family had autosomal dominant retinitis pigmentosa caused by a single point mutation in codon 347 of the rhodopsin gene. The youngest, an 11-year-old girl, had an abnormal electroretinographic response, although her fundus appeared normal. The other affected family members noticed night blindness in the second decade. Their fundi showed diffuse pigmentation with concentric visual field loss, and there was no recordable electroretinographic response. Cataract developed in the fourth decade in the older patients. Good visual acuity was retained however, even in the fifth decade, after cataract extraction. These clinical features were similar to those of American patients (European family origin) with the same mutation of the rhodopsin gene reported previously.

Adult↗