Biomedical subjects

Kiyoo Nakayasu

Publications and source records attributed to Kiyoo Nakayasu.

10 recordsLinked to original sources

PubMed2006

[A case of monoclonal gammopathy with corneal stroma deposits].

BACKGROUND: Monoclonal gammopathy is a group of disorders characterized by proliferation of a single clone of plasma cells that produce monoclonal protein. Sometimes benign monoclonal gammopathy that is a symptomatic can turn into a malignancy like multiple myeloma. We present a case of monoclonal gammopathy with corneal deposits which was treated with deep lamellar keratoplasty (DLKP). The corneal button obtained at the time of DLKP was studied with both light and electron microscopy. CASE: Fine corneal deposits developed bilaterally in a 69-year-old man. There was no family history of ocular diease. RESULTS: We diagnosed monoclonal gammopathy in a blood test that showed elevation of serum immunoglobulin G and the Kappa chain. The corneal button obtained during DLKP was analyzed histologically and ultrastructurally. Electron microscopy showed electron-dense deposits composed of fine parallel filaments in the corneal epithelium and stroma. CONCLUSIONS: Corneal deposits of unknown origin might turn into monoclonal gammopathy that could be a life-threatening disease. It is important for ophthalmologists to check the whole body of a patient when finding corneal deposits.

Aged↗

PubMed2004

Microarray analysis identified differentially expressed genes in keratocytes from keratoconus patients.

PURPOSE: To identify differentially expressed genes in human keratoconus keratocyte by cDNA microarray. METHODS: Normal and keratoconic cornea were cultured for keratocytes. RNA was extracted. cDNA probe labeled with fluorescence dye was made from Poly A+ RNA, hybridized with microarray slide, containing 164 human apoptosis genes. Signal intensity was measured. Expression ratio between keratoconus and normal was determined using ImaGene Ver.3.0. Identified genes were further evaluated by RT-PCR and real-time PCR. RESULTS: Five over-expressed and four under-expressed genes were identified. Of these, differential expression of tumor necrosis factor alpha-induced protein 6 (TNFAIP6), human insulin-like growth factor binding protein 5 (IGFBP5), and IGFBP3 were verified and confirmed by RT-PCR. Real-time PCR showed TNFAIP6 increased by 3.3 folds, while IGFBP5, IGFBP3 decreased by 14 and 11 folds respectively. CONCLUSIONS: The identified genes could be important and deserve further investigation. Significant differential expression of TNFAIP6, IGFBP5, and IGFBP3 may indicate an important role of these genes in the mechanism underlying stromal thinning.

Adult↗

PubMed2003

Long-term follow-up for bullous keratopathy after sato-type anterior-posterior corneal refractive surgery.

PURPOSE: To evaluate cases of bullous keratopathy resulting from anterior-posterior radial corneal keratotomy (Sato-type operation) performed from 1951 to 1959. DESIGN: Observational case series. METHODS: Records for a total of 220 eyes of 139 patients with follow-up examinations were examined. The age at operation vs time to occurrence of bullous keratopathy after the original operation was evaluated in four age groups. Endothelial cell density was measured in 11 long-term postoperative eyes. RESULTS: The mean time to development of bullous keratopathy after surgery was 26.9 +/- 8.8 years (mean +/- SD; n = 173 eyes). The length of this period was not affected by the age of the patient at the time of the original surgery. Average endothelial cell density in 11 eyes of 11 patients 28.5 +/- 3.7 years after surgery was 639 +/- 135 cells/mm(2). CONCLUSIONS: Although some corneas remained clear more than 26 years after anterior-posterior radial keratotomy, the risk of late corneal decompensation continues to exist for these patients.

Cell Count↗

PubMed2003

Mutations in the CHST6 gene in patients with macular corneal dystrophy: immunohistochemical evidence of heterogeneity.

PURPOSE: Macular corneal dystrophy (MCD) is an autosomal recessive disorder leading to severe visual impairment. The carbohydrate sulfotransferase 6 (CHST6) gene, which encodes the corneal N-acetylglucosamine 6-O-sulfotransferase on 16q22 has been identified as a causative gene for MCD. The purpose of this study was to identify mutations in CHST6 in Japanese patients with MCD and evaluate them by means of immunohistochemistry. METHODS: CHST6 was screened in 7 patients and 45 healthy control subjects. Genomic DNA was isolated, and the open reading frame (ORF) of CHST6 was amplified by polymerase chain reaction (PCR). PCR products were analyzed by direct sequencing and restriction enzyme digestion. Immunohistochemistry with a monoclonal anti-keratan sulfate (KS) antibody was performed on corneas of four patients from three families. RESULTS: Three novel mutations (P204Q, R205L, and R177H) and two previously reported mutations (R211W and A217T) were identified in the ORF of CHST6. P204Q, R205L, and R211W were found to be homozygous and R177H and A217T compound heterozygous with R211W on another allele. Immunohistochemistry revealed that R205L homozygous cornea had negative reactivity against the anti-KS antibody, representing type I MCD, and that R211W homozygous and R211W/A217T compound heterozygous corneas had negative or very weak reactivity in the stroma with antibody positive deposits, which were distinct from any previously reported types. CONCLUSIONS: Two mutations (homozygoous R211W and compound heterozygous R211W/A217T) should be subclassified immunohistochemically into new phenotypes of MCD. This heterogeneity could provide further insights into the pathogenesis of MCD.

Amino Acid Sequence↗

PubMed2002

[Evaluation of ophthalmic visicoelastic devices in rabbit penetrating keratoplasty--the protective effect for corneal endothelial cells after autokeratoplasty and the effect of intraocular pressure after aqueous exchange].

PURPOSE: To investigate the effect of sodium hyaluronate molecular weight on corneal endothelial cells and intraocular pressure after penetrating keratoplasty in rabbits. MATERIAL AND METHOD: Rotating autokeratoplasty was carried out on rabbits using six groups of sodium hyaluronate in which the molecular weight differed. Then the endothelial cell density, hexagonal cell rate, corneal thickness, and intraocular pressure were measured. The intraocular pressure in the rabbit eyes after aqueous exchange with six groups of sodium hyaluronate was also measured. RESULTS: The endothelial cell density and hexagonal cell rate in the hyaluronate group of molecular weight 1.53-2.13 million and 1.9-3.9 million were the same as in the eye groups receiving no manipulation. As for the intraocular pressure after aqueous exchange, the highest intraocular pressure was more than 40 mmHg in the group treated with hyaluronate over 1.9 million and the group treated with hyaluronate and chondroitin sulfate compounding agent. CONCLUSION: Endothelial protection was considered to be superior when hyaluronate with a molecular weight of 1.5-3.9 million was used in rabbits. However, it is grossible that leaving a large amount of hyaluronate with a molecular weight over 1.9 million in the eye may lead to a remarkable increase in the early postoperative intraocular pressure.

Animals↗

PubMed2002

[Gelatinous drop-like corneal dystrophy: mutation analysis of membrane component, chromosome 1, surface marker 1].

PURPOSE: To investigate mutation in membrane component, chromosome 1, surface marker 1(M1 S1) gene for patients and unaffected relatives of gelatinous drop-like corneal dystrophy(GDLD). MATERIALS AND METHODS: We performed mutation analysis for 11 patients and 18 unaffected relatives from 7 unrelated families with GDLD. They were followed at the Department of Ophthalmology, Juntendo University, Tokyo, and St. Luke's International Hospital, Tokyo. RESULTS: Ten patients including the affected members of 6 families were detected to be homozygotes by transition of a C to T at nucleotide position 352, replacing a glutamine at codon 118 with a stop codon (Q118X), and unaffected relatives were heterozygous for the mutation. One patient and his parents and brother from one family have had no mutation in open reading frame of the M1S1 gene. CONCLUSIONS: In these 6 families the genotypes of Q118X mutation on M1S1 gene were co-segregated with the phenotype. For the patients who have had no mutation, we need further investigation of the 5' upper site, and it is possible that there is another candidate gene for GDLD.

Antigens, Neoplasm↗

PubMed2002

[Estimation of patient visit rate and incidence of keratoconus in the 23 wards of Tokyo].

PURPOSE: To estimate the patient visit rate and the incidence of keratoconus in the 23 Wards of Tokyo. SUBJECTS AND METHODS: We searched for keratoconus patients with questionnaires sent to 141 hospitals in the 23 Wards of Tokyo. The patient visit rate was estimated using the number of patients from 15 to 44 years old. The incidence was estimated from the number of patients in whom the onset of the disease was at the age 15 to 34. RESULTS: Three hundred and twenty-five patients (205 males and 120 females) were found during a survey of three months. The return rate of the questionnaires was 49.6%. Male/female ratio was 1.7/1.0. The patient visit rate of keratoconus during three months was estimated to be 12.4 x 10(-5) (1/8,100) in males and 6.7 x 10(-5) (1/15,000) in females. The annual incidence was estimated to be 12.1 x 10(-5) (1/8,300) in males and 5.6 x 10(-5) (1/17,900) in females. 6.5% of the patients were given corneal transplants. CONCLUSION: We estimated the patient visit rate and the incidence of keratoconus on the basis of the survey of hospitals of the 23 Wards of Tokyo during a 3-month period. Compared with the previous reports, our data suggests that the proportion of women is increasing in patients with keratoconus, and that the ratio of patients who have to receive corneal transplant therapy are decreasing. A large-scale epidemiological study is required.

Adolescent↗

PubMed2002

[Expression of estrogen receptors alpha and beta, androgen receptors and progesterone receptors in human cornea].

PURPOSE: Using immunohistochemical techniques and reverse transcription polymerase chain reaction (RT-PCR), we examined the localization of estrogen receptors alpha and beta (ER alpha, beta), androgen receptor (AR), and progesterone receptor (PR) in human corneas. MATERIALS AND METHODS: Using formalin-fixed donor human cornea, we did immunohistochemical staining after making transverse sections, and examined the localization of receptors. Also, we extracted mRNA from primary culture cells of the corneal epithelium and stroma as well as the endothelial cell layer and epithelial layer of the cornea, and we performed RT-PCR and examined the expression of each receptor. RESULTS: Immunohistochemical staining revealed that ER alpha was localized in corneal epithelial cells as well as in corneal stromal cells, and ER beta, AR and PR were localized in corneal epithelial, stromal, and endothelial cells. ER alpha, ER beta, and AR mRNA expression was observed in cultured and in vivo epithelium and cultured stroma cells. PR mRNA was expressed not only in cultured and in vivo epithelium and in cultured stroma cells but also in endothelium. CONCLUSIONS: We detected the localization of estrogen receptors alpha and beta, androgen receptors, and progesterone receptors in the human cornea.

Adult↗

PubMedDate not supplied

Analysis of COL8A2 gene mutation in Japanese patients with Fuchs' endothelial dystrophy and posterior polymorphous dystrophy.

PURPOSE: To determine whether Japanese patients with Fuchs' endothelial corneal dystrophy (FECD) and posterior polymorphous dystrophy (PPMD) carry mutations in the COL8A2 gene, and to investigate the possible pathogenicity of the COL8A2 gene in these corneal dystrophies. METHODS: DNA analysis of the COL8A2 gene was performed in 15 unrelated Japanese patients with FECD, and 5 patients with PPMD using polymerase chain reaction and direct sequencing. Mutation screenings were also performed in 36 unrelated normal volunteers as controls, as well as slit-lamp and specular microscopy. RESULTS: Two types of heterozygous missense mutations of the COL8A2 gene (R155Q and T502M) in 5 of 15 FECD probands (R155Q, 3/30 chromosomes, 10.0%; T502M, 3/30 chromosomes, 10.0%) were found. No mutation was detected in the coding region of the COL8A2 gene in the remaining 10 patients with FECD nor in any of the 5 patients with PPMD. These two mutations were also found in normal Japanese volunteers (R155Q, 5/72 chromosomes, 6.9%; T502M, 11/70 chromosomes, 15.7%). The chromosomal frequency of the two mutations was not significant between the patients and normal controls. CONCLUSIONS: The R155Q and T502M mutations of COL8A2 may not be the causative defect in the Japanese FECD and PPMD patients examined in this study.

Aged↗

PubMedDate not supplied

High level of Fc epsilon receptor I-bindable immunoglobulin E in the tear fluid and increased immunoglobulin E-saturated cells in the giant papillae of vernal keratoconjunctivitis patients.

PURPOSE: To investigate the concentrations of Fc epsilon receptor I (Fc epsilon RI)-bindable immunoglobulin E (IgE) in the tear fluid and the proportion of IgE-saturated cells among Fc epsilon RI-positive cells in giant papillae from vernal keratoconjunctivitis (VKC) patients. METHODS: The tear fluids and giant papillae were obtained from 8 VKC patients with their informed consent. To detect the quantitative difference between Fc epsilon RI-bindable IgE and total IgE in the tear fluid, we used a new enzyme-linked immunosorbent assay system we have developed. Next, to estimate the proportion of IgE-saturated cells among Fc epsilon RI-positive cells, we used two distinct monoclonal antibodies for Fc epsilon RI for the immunohistochemistry. One antibody recognizes all Fc epsilon RI regardless of whether it is with or without receptor-bound IgE. The other does not recognize IgE-bound Fc epsilon RI. RESULTS: The quantitative difference between Fc epsilon RI-bindable IgE and total IgE were detected in the tear fluid of VKC patients. Fc epsilon RI-positive cells were significantly increased in the giant papillae of VKC compared with normal conjunctivae. The proportion of IgE-saturated cells among Fc epsilon RI-positive cells in giant papillae was higher than that in normal conjunctivae. CONCLUSION: These results suggest that F epsilon RI-bindable IgE may be a critical factor to estimate the severity of VKC.

Antibodies, Monoclonal↗