Biomedical subjects

A Kanai

Publications and source records attributed to A Kanai.

At least 55 records · Page 3Linked to original sources

PubMed1999

Anti VLA-4 monoclonal antibody inhibits eosinophil infiltration in allergic conjunctivitis model of guinea pig.

PURPOSE: To determine the contribution of very late activation antigen-4 (VLA-4) molecule to eosinophil infiltration into the conjunctiva in an actively sensitized allergic conjunctivitis model of guinea pig, effects of a monoclonal antibody against VLA-4 was examined in vivo. METHODS: A rat anti-mouse VLA-4 mAb (PS 2. 3), which cross-reacts with guinea pig VLA-4, inhibited the adhesion and transmigration of guinea pig eosinophils to /through human umbilical vein endothelial cells (HUVEC) in vitro. Hartley guinea pigs were actively sensitized by intraperitoneal injection of ovalbumin with aluminum hydroxide. Two weeks later, 2.5% ovalbumin was dropped into the eye for the antigen challenge. In the treatment group, 4 mg/kg (body weight) of the anti VLA-4 mAb (PS2.3), and in the control group, the same amount of a control Ab was intraperitoneally injected respectively at 4 hours before the antigen challenge. From both groups, the eyelids and eyeballs were excised at 2, 4, 10, and 24 hours after the antigen challenge, fixed, stained with Hansel solution and the number of the infiltrating eosinophils in the conjunctiva was counted. RESULTS: In the control group, infiltration of eosinophils to the conjunctiva increased with time, peaked at 12 hours, and then gradually decreased until 24 hours after the antigen challenge. In the anti VLA4-mAb treated group, eosinophil infiltration was almost completely inhibited at least until 24 hours after the antigen challenge. CONCLUSION: VLA-4 molecule was elucidated to play a critical roll in the eosinophil infiltration in experimentally-induced allergic conjunctivitis model of guinea pig.

Animals↗

PubMed1999

Visual impairment and REP-1 gene mutations in Japanese choroideremia patients.

Choroideremia (CHM), an X-linked recessive hereditary disease, is an intractable chorioretinal dystrophy. The rate of disease progression of CHM reportedly shows considerable variability. A number of mutations involving the gene that codes for Rab escort protein-1 (REP-1) have been detected in CHM patients. We have analyzed REP-1 gene mutations of Japanese CHM patients. The present study was designed to investigate the clinical variability and the genotype to phenotype relationship in 15 Japanese CHM patients referred to the Department of Ophthalmology of Juntendo University Hospital. The clinical investigation of visual acuity, visual field, color vision and refraction revealed inter-individual variability. Mutation analyses of the REP-1 gene revealed 10 types of mutations in 13 patients from 11 families, including an insertion, small deletions, nonsense mutations and an A to CC mutation. In 13 CHM patients with detectable REP-1 gene mutations, no relationship of genotype to phenotype was detected. At present, we consider the REP-1 genotype to be an unreliable prognostic factor for counseling of CHM patients. In two patients from one family, no mutations were detected in coding regions of the REP-1 gene. These patients may have intron mutations of the REP-1 gene, not detectable by the techniques employed in this study, or other causative genes. Both were observed to have somewhat slower disease progression than the other 13 patients. More advanced analyses are necessary to answer questions regarding the genotype-phenotype relationship in CHM patients.

Adaptor Proteins, Signal Transducing↗

PubMed1999

Secondary mutations of mitochondrial DNA in Japanese patients with Leber's hereditary optic neuropathy.

PURPOSE: Based on studies on the pathogenesis of Leber's hereditary optic neuropathy (LHON), mitochondrial DNA (mtDNA) mutations have been divided into two types: primary and secondary. Primary mutations at nucleotide positions (nt) 11778, 3460, and 14484 can each cause LHON. Secondary mutations may be simultaneously found in LHON patients with a primary mutation, may occur at higher frequency in LHON patients than in normal controls, and may play an additional role in the pathogenesis of LHON. We examined the frequencies of secondary mutations of mtDNA at nt3394, 7444, 9438, 9804, 13708, and 15257 in 19 Japanese patients with LHON associated with primary mutations and 108 normal controls. METHODS: Mutations were determined by restriction enzyme analysis or DNA sequencing using polymerase chain reaction (PCR) products. RESULTS: One patient with an nt11778 mutation also had an nt13708 mutation. Another patient with an nt3460 mutation also had an nt7444 mutation. During DNA sequencing of the PCR fragment harboring nt3394, three novel mutations in the ND1 gene (nt3316, 3496, and 3497 mutations) were found in three patients with an nt11778 mutation. The frequency of these mutations in 108 control subjects was studied further: one (0.9%) had an nt3394 mutation, none (0%) had an nt9804 mutation, one (0.9%) had an nt13708 mutation, two (1.9%) had nt3316 mutations, one (0.9%) had an nt3496 mutation, and two (1.9%) had nt3497 mutations. CONCLUSION: It is unlikely that the frequencies of secondary mutations in Japanese patients with LHON are higher than those in normal Japanese controls. It is possible that the mutations at nt3316, 3496, and 3497 are secondary mutations of LHON.

Adult↗

PubMed1999

Missense mutation in the alternative splice region of the PAX6 gene in eye anomalies.

The PAX6 gene is involved in ocular morphogenesis, and PAX6 mutations have been detected in various types of ocular anomalies, including aniridia, Peters anomaly, corneal dystrophy, congenital cataract, and foveal hypoplasia. The gene encodes a transcriptional regulator that recognizes target genes through its paired-type DNA-binding domain. The paired domain is composed of two distinct DNA-binding subdomains, the N-terminal subdomain (NTS) and the C-terminal subdomain (CTS), which bind respective consensus DNA sequences. The human PAX6 gene produces two alternative splice isoforms that have the distinct structure of the paired domain. The insertion, into the NTS, of 14 additional amino acids encoded by exon 5a abolishes the DNA-binding activity of the NTS and unmasks the DNA-binding ability of the CTS. Thus, exon 5a appears to function as a molecular switch that specifies target genes. We ascertained a novel missense mutation in four pedigrees with Peters anomaly, congenital cataract, Axenfeldt anomaly, and/or foveal hypoplasia, which, to our knowledge, is the first mutation identified in the splice-variant region. A T-->A transition at the 20th nucleotide position of exon 5a results in a Val-->Asp (GTC-->GAC) substitution at the 7th codon of the alternative splice region. Functional analyses demonstrated that the V54D mutation slightly increased NTS binding and decreased CTS transactivation activity to almost half.

Abnormalities, Multiple↗

PubMed1999

Large-scale sequencing of the rabbit corneal endothelial cDNA library.

PURPOSE: This study sought to identify novel or active genes in corneal endothelial cells with description of the gene-expression profile. METHODS: We performed the single-pass sequencing of 1,000 clones from a rabbit corneal endothelial cDNA library. Inserts of the library were amplified by polymerase chain reaction (PCR), sequenced, and compared with several databases. We used four database similarity search programs: FASTA, BLASTN, TBLASTX, and BLASTX. RESULTS: Of the sequences generated, 618 (61.8%) showed sequence homology with known genes, whereas 192 (19.2%) matched previous reported expression sequence tags (ESTs) and 174 (17.4%) showed no sequence similarity. Among the homologous clones to known genes are collagen type VIII, secreted protein acidic and rich in cysteine (SPARC), lysyl oxidase, phosphatidylcholine-2-acylhydrolase, and thrombospondin. Several matched ESTs, and no matched clones that showed high frequency were also detected. CONCLUSION: Large-scale sequencing can be useful in obtaining a profile of the active genes. Several ESTs showed relatively frequent expression, suggesting that these genes may have important functions in the corneal endothelium.

Animals↗

PubMed1999

Corneal deposits as an alerting sign of monoclonal gammopathy: a case report.

PURPOSE: To report the clinical and histopathologic findings of the corneal deposits in a patient with monoclonal gammopathy. METHODS: Amorphous corneal deposits developed bilaterally in a 55-year-old woman. The corneal button obtained during penetrating keratoplasty was analyzed histologically, immunohistochemically, and ultrastructurally. RESULTS: The patient was diagnosed as having monoclonal gammopathy because of the elevation of serum immunoglobulin G (IgG) and kappa light chain. Histologic evaluation disclosed that the deposits were eosinophilic, periodic acid-Schiff positive, and stained red with Masson's trichrome. Immunohistochemical examination showed that these deposits reacted positively for IgG and the kappa light chain. Electron microscopy showed electron-dense deposits composed of parallel fine filaments with a periodicity of 10-13 nm. CONCLUSIONS: We conclude from the immunohistochemical results that monoclonal gammopathy can lead to corneal deposits that are dense enough to decrease vision. Because monoclonal gammopathy may be a life-threatening disease and early diagnosis is important, ophthalmologists should be aware that corneal deposits can be an alerting sign of monoclonal gammopathy.

Cornea↗

PubMed1999

Corneal wound healing following laser in situ keratomileusis (LASIK): a histopathological study in rabbits.

AIMS: To investigate the histopathological changes of rabbit corneas after laser in situ keratomileusis (LASIK) and to evaluate the corneal wound healing process. METHODS: A LASIK was performed on white rabbit eyes. Postoperatively, rabbits were killed on days 1 and 7, and at 1, 3, and 9 months. RESULTS: Periodic acid Schiff (PAS) positive material and disorganised collagen fibre were seen along the interface of the corneal flap even 9 months after operation. CONCLUSIONS: The wound healing process still continued at 9 months after LASIK indicating that a much longer time than expected was required for corneal wound healing following LASIK.

Animals↗

PubMed1999

Analysis of glycosaminoglycans in rabbit cornea after excimer laser keratectomy.

BACKGROUND/AIMS: The biochemical basis for the development of subepithelial opacity of the cornea after excimer laser keratectomy has yet to be fully defined. The aim of this study was to evaluate the alterations of glycosaminoglycans (GAGs) after excimer laser keratectomy. METHODS: Rabbit corneas were harvested on days 5, 10, 20, and 30 after excimer laser photoablation. The amount of main disaccharide units was determined by high performance liquid chromatography (HPLC). In addition, immunohistochemical studies were performed on corneal sections 20 days after the ablation. RESULTS: The concentrations of DeltaDi-0S at 5 and 10 days were significantly lower than before the ablation. DeltaDi-6S showed a significant increase 5 days after the ablation but DeltaDi-4S did not show any significant change. There was a significant increase in DeltaDi-HA at 20 and 30 days after ablation. In immunohistochemistry, the positive staining for DeltaDi-6S and hyaluronic acid was observed in the subepithelial region. These immunohistochemical results were well correlated with the HPLC findings. CONCLUSIONS: The increase in chondroitin-6 sulphate and hyaluronic acid may be related to corneal subepithelial opacity after excimer laser keratectomy.

Animals↗

PubMed1999

[Long-term healing of excimer laser ablated rabbit corneas].

PURPOSE: To evaluate histologically and immunohistochemically long-term changes in rabbit cornea following excimer laser ablation. MATERIALS AND METHODS: Excimer laser keratectomy was performed on 12 eyes of 6 rabbits. The corneas were subjected to histological and immunohistochemical studies 2 and 3 years after treatment. FINDINGS: In all specimens, epithelial basement membrane of the ablated central cornea showed undulating and spike-pattern invasion into the epithelial side. The collagen lamellae showed irregularities in the subepithelial stroma. Immunohistochemically, the subepithelial stroma showed positive reaction to anti-type III collagen antibody. Staining for anti-IV collagen antibody showed a linear pattern in the epithelial basement membrane and was positive in the subepithelial stroma of the ablated central cornea. These positive reactions to anti-type III and type IV collagen antibodies in the stroma showed the localized presence of scar tissue in the ablated stroma. Antibody to type VII collagen showed weak reaction in the basement membrane, suggesting incomplete regeneration of anchoring fibrils. CONCLUSION: The healing process was still incomplete 3 years after excimer laser keratotomy in rabbits.

Animals↗

PubMed1999

[The effect of neurotransmitters on rabbit cornea].

PURPOSE: To ascertain the effect of neurotransmitters added to the culture medium of rabbit corneal epithelium and stromal cells. METHOD: The corneal epithelium and stromal cells were cultured in RCGM medium. Three neurotransmitters were added to the medium : substance P, acetylcholine, and vasoactive-intestinal peptide (VIP). RESULTS: Proliferation of epithelial cells significantly increased after incubation for 24 hours with substance P (p < 0.05). There was no change in proliferation after addition of acetylcholine or VIP. The extension of epithelial cell layer increased after addition of substance P but not after addition of acetylcholine or VIP. No change was induced in proliferation of stromal cells or extension of the stromal cell layer after addition of any one of the three substances. CONCLUSION: Substance P stimulates the proliferation of corneal epithelial cells when added to the culture medium.

Acetylcholine↗

PubMed1999

[Corneal wound healing and immunohistological features of extracellular matrix following penetrating keratoplasty in rabbits].

PURPOSE: To analyze corneal wound healing after penetrating keratoplasty (PKP). MATERIALS AND METHODS: We performed PKP on 20 white rabbit eyes, and applied immunohistochemical techniques. The distribution of type I, III and IV collagens, large proteoglycan, chondroitin 6-sulfate, chondroitin 4-sulfate, and vimentin was determined at postoperative intervals of 3 days, 1 week, 2 weeks, 1 month and 3 months. RESULTS: By day 3, staining for type IV collagen was observed along the host-graft junction. By day 7, staining for type III collagen, large proteoglycan and chondroitin 6-sulfate had increased in the repair region, and then diminished with increasing postoperative time. Epithelial wound healing required more than one month, whereas the remodeling of Descemet's membrane did not terminate at 3 months after PKP. CONCLUSION: The data from this study suggest that type III collagen, large proteoglycan and chondroitin 6-sulfate play a crucial role in the corneal wound healing after PKP.

Animals↗

PubMed1999

[Effect of vitamin A palmitate on the synthesis of mucins in cultured conjunctiva].

PURPOSE: To evaluate the effect of vitamin A palmitate on the synthesis of mucins from goblet cells in cultured rabbit conjunctiva. METHODS: Palpebral conjunctiva was obtained from 12 white rabbits and was cultured in serum-free RCGM 2 which was developed for culture of rabbit corneal epithelial cells. This method eliminated retinol in the serum. High-performance liquid chromatography was used in quantitating N-acetylneuraminic acid contained in the sugar chain as an indicator of mucin content. RESULTS: Addition of vitamin A palmitate to the cultured medium resulted in significant increase in the amount of N-acetylneuraminic acid in the medium. CONCLUSIONS: The increase in N-acetylneuraminic acid in the cultured medium suggests that the increase of goblet cells in cultured conjunctiva is related to the synthesis of mucins due to vitamin A. RCGM 2 as a culture medium promises to be useful in evaluating the pharmacological activity of vitamin A. High-performance liquid chromatography facilitated quantitation of mucins in the culture medium.

Animals↗

PubMed1999

[Effect of vitamin A palmitate on vitamin A-deficient rabbits].

PURPOSE: We examined the effects of vitamin A palmitate (VA pal) eyedrops on the symptoms caused by vitamin A-deficiency in rabbits. METHODS: Three-week-old rabbits were raised on a vitamin A-deficient diet, and were examined for the quantity of retinol in the serum and the condition of the anterior segment of the eye. The vitamin A-deficient animals were treated with VA pal eyedrops. RESULTS: The retinol in the serum began to decrease seven months after the animals were placed on the vitamin A-deficient diet. After ten months, superficial punctate keratitis and the loss of conjunctival goblet cells were observed. Treatment of the disease in the anterior segment of the eyes with VA pal eyedrops resulted in restoration of normal condition within 3 weeks. The treatment increased the goblet cells in the ocular conjunctiva and the retinol in the serum. CONCLUSIONS: These results show the efficacy of topical VA pal treatment for vitamin A-deficient rabbits.

Animals↗

PubMed1999

[A case of juvenile retinoschisis diagnosed by analysis of the XLRS 1 gene].

BACKGROUND: We report on a 3 year-old boy who was first diagnosed with retinal detachment and macular hole and received surgical treatment. X-linked juvenile retinoschisis was determined by DNA analysis. CASE: Past or family history was not recognized. There was left macular hole but no typical spoke-like foveal retinoschisis was observed in either eye. We could not diagnose the case as X-linked juvenile retinoschisis because there was no family history of it, central foveal reflex was observed in right eye with corrected visual acuity of 1.2, and no abnormality was recorded in the electroretinogram. High molecular weight DNA was extracted from peripheral leukocytes, and the XLRS 1 gene was analyzed. Hemizygous missense mutation, Arg102Gln, was detected. We diagnosed the disease as X-linked juvenile retinoschisis because the Arg102Gln mutation was detected in a family in Germany, two families in the United Kingdom, and two families in the USA. CONCLUSION: XLRS 1 gene analysis is useful if the diagnosis is difficult clinically due to atypical clinical findings.

Child, Preschool↗

PubMed1998

Familial subepithelial corneal amyloidosis (gelatinous drop-like corneal dystrophy): exclusion of linkage to lactoferrin gene.

PURPOSE: Because corneal tissue with familial subepithelial corneal amyloidosis (FSCA; gelatinous drop-like dystrophy of the cornea) contains lactoferrin the possibility that the FSCA gene was the human lactoferrin (hLF) gene was investigated. Due to contradictory published information we also mapped the hLF gene. METHODS: We mapped the hLF gene using a genomic clone of the entire hLF gene as a probe by fluorescence in situ hybridization (FISH). Utilizing PCR primers that are specific to the hLF gene, we also mapped the hLF via radiation somatic cell hybrid analysis. Linkage of the FSCA gene to the hLF gene was evaluated by genetic linkage analysis using polymorphic markers within and in the vicinity of the hLF gene. RESULTS: The hLF gene mapped to the short arm of chromosome 3 at 3p21. Linkage analysis using polymorphic markers for hLF and haplotype analysis of the 3p21 loci indicates that the FSCA gene is not linked to the 3p21 locus. CONCLUSIONS: The gene for FSCA is not the hLF gene in these families.

Amyloidosis↗

PubMed1998

Japanese juvenile retinoschisis is caused by mutations of the XLRS1 gene.

We investigated the XLRS1 gene in Japanese patients with retinoschisis (RS). All exons of the XLRS1 gene were sequenced in 14 males, including a pair of monozygotic twins, from 11 individual families with RS and five of their mothers who are asymptomatic but diagnosed as carriers. Six kinds of missense mutations and a nonsense mutation, including six novel mutations, were detected in all 14 patients and carriers. Mutations in the XLRS1 gene are also responsible for RS in non-Caucasian patients. Most Japanese RS cases are caused by an XLRS1 gene defect. A novel mutation, Glu72Lys, was found in four families, suggesting a common mutation in the Japanese population. Clinical features of RS patients with both the Glu72Lys and Pro193Leu mutations indicate that a genotype-phenotype correlation is not recognized in RS.

Eye Diseases, Hereditary↗

PubMed1998

The incidence and characteristics of silent cerebral infarction in elderly diabetic patients: association with serum-soluble adhesion molecules.

The purpose of this study was to investigate the relationship between complications arising from silent cerebral infarction (SCI) and changes in the levels of serum-soluble adhesion molecules in 82 elderly diabetic patients aged 60 years and older. SCI was found in 43 % of the 82 patients, with incidence increasing in relation to age. The prevalence of SCI was higher in subjects with hypertension, poor metabolic control and increased fibrinolysis. The levels of soluble intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1) and E-selectin (sE-selectin) were higher in diabetic patients than in non-diabetic subjects (p < 0.05, p < 0.001, and p < 0.05, respectively). Also, sICAM-1 and sVCAM-1 were found at increased levels in diabetic patients with SCI compared to those without SCI (p < 0.01 and p < 0.05, respectively). In particular, the level of sICAM-1 was increased in patients with SCI due to perforating arterial occlusion, while the level of sVCAM-1 was increased in patients with SCI due to cortical arterial occlusion. However, no significant difference was found in sE-selectin levels. Overall average of the intima and media thickness (IMT) of the common carotid arteries increased with age. IMT proved to be greater in patients with SCI than in patients without SCI (p < 0.05), and showed a weak but significant positive correlation with sVCAM-1, while no correlation was found with either sICAM-1 or sE-selectin levels. In conclusion, measurement of serum adhesion molecules may be useful for diagnosing the early stages of brain damage and for prophylactic treatment which may prevent the onset or progression of SCI.

Aged↗

PubMed1998

A new L527R mutation of the betaIGH3 gene in patients with lattice corneal dystrophy with deep stromal opacities.

Mutations in the betaIGH3 gene on chromosome 5q31 cause five distinct autosomal dominant corneal dystrophies: granular Groenouw type I, Reis-Bücklers', lattice type I and IIIA. and Avellino corneal dystrophies. We present here a new mutation of the betaIGH3 gene in patients with late-onset lattice corneal dystrophy manifest as a deep stromal opacity. To test the previously reported R124C, R124H, P501T, R555W, and R555Q mutations of the betaIGH3 gene, 30 patients and 11 normal relatives from 16 independently ascertained families with lattice corneal dystrophy, 49 patients and 12 normal relatives from 40 independently ascertained families with other corneal dystrophies, and 40 unrelated normal volunteers, were analyzed. A L527R (CTG/CGG) mutation of the betaIGH3 gene was found in 6 unrelated patients with lattice corneal dystrophy. A retrospective review of the patients' records showed that the opacities were deep in the stromal layer and of late onset. The mutation was a heterozygous single base-pair transversion from T to G of the second nucleotide position of codon 527. This caused the substitution of arginine for leucine. These six patients did not have mutations in codons 124, 501, or 555. The L527R mutation was not detected in the other corneal dystrophies or 40 normal volunteers. Although phenotypic variations in the size and shape of the deposits were found, all patients with the L527R mutation showed deposits deep in the stromal layer. We conclude that there are now at least six different mutations that have been detected in the betaIGH3 gene on chromosome 5q31 and that lead to corneal dystrophy.

Aged↗