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Biomedical subjects

Y Tano

Publications and source records attributed to Y Tano.

At least 127 records · Page 7Linked to original sources
PubMed1998

Neutrophil chemotaxis induced by corneal epithelial cells after herpes simplex virus type 1 infection.

PURPOSE: Neutrophil invasion is a primary event in the development of herpetic keratitis. It has been reported that HSV-1 infection of keratocytes induces the synthesis of IL-8, a potent neutrophil chemoattractant, while corneal epithelium does not. Nevertheless, little is known about the correlation between neutrophil migration and the production of chemotactic factors by HSV-1-infected corneal cells, especially in epithelial cells which form an initial barrier of the ocular surface. We examined whether human corneal epithelial cells as well as keratocytes could induce neutrophil chemotaxis in response to HSV-1 infection. METHODS: Human corneal epithelial cells immortalized with SV40 (HCE) and human keratocytes were infected with HSV-1. The culture fluids collected at 4, 12, 24 h after infection were assayed for human neutrophil chemotaxis using a modified Boyden chamber method. IL-8 levels in these supernatants were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: The chemotactic activity induced by HCE and keratocytes after MP strain of HSV-1 infection peaked as early as 4 h postinfection, then declined. Chemotactic activity induced by HSV-1-infected HCE and IL-8 levels on these supernatants paralleled with the infectious virus titer. It was inhibited by monoclonal anti-IL-8 antibody. UV-inactivation of MP strain abrogated neither the induction of chemotactic activity nor IL-8 secretion of infected HCE. CONCLUSIONS: At the early phase of HSV-1 infection, corneal epithelial cells play an important role in inducing neutrophil chemotaxis, which was mediated by IL-8.

Cell Line↗
PubMed1998

Severe corneal dystrophy phenotype caused by homozygous R124H keratoepithelin mutations.

PURPOSE: To determine the mutational status of the beta ig-h3 gene in five patients from four Japanese families affected with an unusual, severe form of corneal dystrophy. In these five cases, the corneas were remarkable for confluent round opacities in the superficial stromal layer. The beta ig-h3 gene coding for keratoepithelin was recently identified as the gene responsible for 5q-linked autosomal dominant corneal dystrophies. METHODS: Genomic DNA was isolated from leukocytes of five patients with the severe form of corneal dystrophy. To screen for point mutations, exons of the beta ig-h3 gene were amplified by polymerase chain reaction and were analyzed with the single-strand conformational polymorphism technique. Subsequently, the mutations were identified by a direct sequencing method and restriction enzyme digestion analysis. RESULTS: All five patients with the severe form of corneal dystrophy had homozygous R124H keratoepithelin mutations. Histopathologic examinations of the corneas obtained from two patients with the severe form showed granular, rod-shaped deposits. CONCLUSIONS: The severe phenotype was a pathologic variant of granular corneal dystrophy (GCD). All five patients had homozygous R124H keratoepithelin mutations. The R124H keratoepithelin mutation is the same mutation recently reported to be responsible for Avellino corneal dystrophy. The homozygous R124H keratoepithelin mutations are the cause of the severe variant of GCD characterized by juvenile-onset and confluent superficial opacity.

Adult↗
PubMed1998

[The diagnostic significance of polymerase chain reaction for ocular samples in viral retinitis].

During the past two years we studied the incidence of infection by eight members of the herpesvirus family in ocular samples (tear fluid, the aqueous, and the vitreous) using the polymerase chain reaction (PCR). A total of 31 ocular samples were collected from 22 eyes of 13 patients. The series comprised five cases of acute retinal necrosis, four of cytomegalovirus retinitis, three of proliferative diabetic retinopathy, and one of ocular malignant lymphoma. In 12 eyes of 9 patients with viral retinitis, causative viral DNA was detected either from the tear fluid (1/12, 8%), the aqueous (6/7, 86%), or the vitreous (1/1, 100%). In the fellow eyes free of viral retinitis, no viral DNA was detected in the samples (6 of tear fluid and one of the aqueous). Out of the other 4 patients without viral retinitis, viral DNA was detected in one patient with ocular malignant lymphoma. The findings show that PCR is a useful and sensitive method in the diagnosis of viral retinitis, but that it may give false positive results. The aqueous and the vitreous samples gave more positive results than tear fluid.

DNA, Viral↗
PubMed1997

Isolation of a cDNA encoding a photoreceptor cell-specific actin-bundling protein: retinal fascin.

We have isolated a novel retina-specific gene, retinal fascin, encoding a new member of actin-bundling protein gene family, from a bovine retina cDNA library. The cDNA encodes a 492 amino acid protein which shows 36-57% amino acid identity with three vertebrate fascins, echinoid fascin and Drosophila singed gene. Northern blot analysis revealed that retinal fascin mRNA was exclusively expressed in the eye and not seen in other tissues examined. In situ hybridization analysis indicated that retinal fascin mRNA signals were found only in the inner segment of the photoreceptor layer and outer nuclear layer, indicating that retinal fascin was specifically expressed in photoreceptor cells. As fascins are actin-bundling proteins important for constructing several intracellular structures, retinal fascin might play a pivotal role in photoreceptor cell-specific events, such as disk morphogenesis.

Amino Acid Sequence↗
PubMed1997

Induction of hepatocyte growth factor in fibroblasts by tumor-derived factors affects invasive growth of tumor cells: in vitro analysis of tumor-stromal interactions.

Invasive and metastatic potentials of several types of carcinoma cells are regulated through interactions with host stromal cells, e.g., tumor-stromal interactions. Because hepatocyte growth factor (HGF), a ligand for the c-Met proto-oncogene product, is a mesenchymal- or stromal-derived factor that induces mitogenic, motogenic, and morphogenic responses, we examined the mechanisms involved in tumor-stromal interactions in vitro. The c-Met/HGF receptor was expressed in A431 human epidermoid carcinoma cells, A549 human non-small cell lung cancer cells, HuCC-T1 human cholangiocellular carcinoma cells, and SBC-3 human small cell lung carcinoma cells. HGF stimulated cell growth, scattering, and invasion of these cells. Although these cells did not produce biologically significant levels of HGF, these cells did secrete soluble factors that potently stimulated HGF production in human skin fibroblasts. These carcinoma cell-derived HGF inducers proved to be interleukin-1 (IL-1) in A431 cells, IL-1 plus basic fibroblast growth factor (bFGF) in A549 and HuCC-T1 cells, and bFGF plus platelet-derived growth factor in SBC-3 cells. When these carcinoma cells were cocultured with fibroblasts, HGF levels in the coculture system were much higher than the levels in fibroblasts alone, without cocultured carcinoma cells. Together with the increase in HGF levels, the number of invasive cells increased, but in vitro invasion of carcinoma cells in the coculture system was strongly inhibited by anti-HGF antibodies. Thus, there are mutual interactions between carcinoma cells and fibroblasts: IL-1, bFGF, and platelet-derived growth factor derived from tumor cells play a role in inducing HGF expression in stromal fibroblasts, whereas fibroblast-derived HGF, in turn, leads to invasive growth in carcinoma cells. The mutual interactions, as mediated by HGF and HGF inducers, may play a significant role in the occurrence of invasion and metastasis of carcinoma cells.

Animals↗
PubMed1997

The double-mirror gonioscopic lens for surgery of the anterior chamber angle.

Intraoperative examination of the anterior chamber angle is necessary during several glaucoma procedures, including goniosynechialysis and goniotomy. Many of the available lenses for this purpose are difficult to use because they require oblique illumination and their size interferes with surgical manipulations at the limbus. We have developed a double-mirror gonioscopic lens that uses direct illumination; provides an upright image of angle structures; and has a small diameter, allowing simultaneous access to the entire limbal region. We compared our lens with the Posner goniomirror (Ocular Instruments, Bellvue, Wash) and found that it provides an equal view of angle structures. The double-mirror gonioscopic lens facilitates the intraoperative visualization of the anterior chamber angle and should allow surgeons who treat glaucoma to more accurately and safely perform angle-related procedures.

Animals↗
PubMed1997

Exotropia secondary to vitreous hemorrhage.

BACKGROUND: Diplopia after cataract surgery has been reported by several authors, but diplopia after recovery from vitreous hemorrhage (VH) has not been described. METHODS: We examined eight patients with manifest exotropia and binocular diplopia after recovery from dense VH by vitreous surgery. VH was bilateral in three patients and unilateral in five, and lasted for an average of 7.7 years. RESULTS: Visual acuity before vitrectomy ranged from 20/200 to light perception; that after vitrectomy ranged from 20/20 to 20/60. Exotropia was present in all patients after vitrectomy. Additionally, seven out of eight patients had vertical strabismus with an average deviation of 6 prism diopters (delta). Fusion was confirmed in four patients with an average amplitude of 13 delta. Four patients underwent horizontal strabismus surgery. Fusion was present in two before strabismus surgery and in all four after surgery; however, unstable diplopia persisted in three of the four after surgery. CONCLUSION: Diplopia after vitrectomy for longstanding VH may occur due to fusion impairment comparable to that occasionally seen after surgery for traumatic cataract.

Adolescent↗
PubMed1997

Horizontal transposition of vertical rectus muscles for treatment of excyclotropia.

BACKGROUND: Horizontal transposition of the vertical rectus muscles has been performed for treatment of excyclotropia associated with congenital absence of the superior oblique, and for residual excyclotropia after the Harada-Ito operation. However, the amount of excyclotropia that can be corrected and whether this technique alters the vertical muscle balance is not well known. We report the surgical results of three patients with pure excyclotropia who underwent unilateral one-half tendon width horizontal transpositions of vertical rectus muscles. METHODS: A one-half muscle width temporal transposition of the superior rectus and nasal transposition of the inferior rectus muscles of one eye was performed in three patients with pure excyclotropia and no associated hypertropia. All three had intermittent torsional diplopia before surgery. RESULTS: Postoperatively, excyclotropia decreased significantly in all fields of gaze, with 8 degrees of reduction by synoptophore and 12.3 degrees of reduction by fundus photography on average. There was no associated vertical or horizontal deviation. All three patients reported improvements of cyclofusion. CONCLUSION: One-half muscle width temporal transposition of the superior rectus and nasal transposition of the inferior rectus muscles was effective in ameliorating excyclotropia and corrected subjective complaints without altering vertical muscle balance.

Adult↗
PubMed1997

Retinal function with lens-induced myopia compared with form-deprivation myopia in chicks.

BACKGROUND: The retina is known to be involved in the development of form-deprivation myopia (FDM); however, it is not clear whether the retinal changes that lead to lens-induced myopia (LIM) are the same as those involved in FDM. To gain insight into the retinal mechanism(s) that cause myopia, we investigated differences in the results of electroretinography (ERG) in eyes with FDM and LIM. METHODS: LIM or FDM was induced in chick eyes by placing various powers of spectacles or an occluder over the left eyes of 6-day-old chicks. After 6 days, the spectacles or occluder was removed, refraction and axial length were measured and ERG was performed. Results for eyes treated with spectacles and those treated with occluders were compared. RESULTS: Refraction and axial length changed concomitant with the power of the lens used, but components of the ERG of eyes with LIM were not related to the power of lens added. Refraction and axial lengths of eyes covered with a -16 D lens did not differ from these values in eyes covered with an occluder. The a- and b-waves were also similar for the two groups. However, oscillatory potentials decreased significantly in the chicks with FDM. CONCLUSIONS: Retinal function differs in LIM and FDM, as indicated by differences in the oscillatory potentials. This difference may stem from the fact that in FDM the retinal image is continuously defocused, whereas images are ultimately focused on the retina in LIM.

Animals↗
PubMed1997

Diamond-dusted silicone cannula for epiretinal membrane separation during vitreous surgery.

PURPOSE: To report a diamond-dusted silicone cannula as a tool for membrane separation during vitreous surgery. METHODS: A diamond-dusted silicone cannula was fashioned from flexible silicone tubing with a beveled tip and coated with diamond fragments for use during vitreous surgery. RESULTS: The instrument was used successfully in seven eyes with idiopathic macular hole and was found to be particularly useful for removing residual vitreous cortex and epiretinal membranes from around the hole. It was also effective in removing "immature membranes" in three eyes with proliferative vitreoretinopathy. CONCLUSION: The diamond-dusted silicone cannula is a useful tool for removing thin epiretinal membranes and vitreous cortex that may be difficult or nearly impossible to remove safely using other techniques.

Catheterization↗
PubMed1997

Sulfur hexafluoride and perfluoropropane do not escape from a plastic syringe closed with a stopcock.

PURPOSE: To evaluate during various intervals of time the escape of long-acting gases contained in a plastic syringe closed with a stopcock or a plastic cap. METHODS: A 60-ml plastic syringe was filled or partially filled with a long-acting gas, either sulfur hexafluoride or perfluoropropane. The tip of the syringe was closed with either a stopcock or the syringe's plastic cap. After various intervals of time, the concentration of the long-acting gas in the syringe was measured by gas chromatography. RESULTS: The concentration of both long-acting gases was higher than 98% at 24 hours after filling when the syringe was closed with a stopcock; however, it was less than 41% when the syringe was filled and capped tightly with its plastic cap. CONCLUSION: The proportion of long-acting gases escaping in 24 hours from a filled syringe capped with a stopcock is clinically insignificant.

Chromatography, Gas↗
PubMed1997

Spontaneous disappearance of traumatic macular holes in young patients.

PURPOSE: To report the disappearance of traumatic macular hole in three eyes of three patients. METHODS: Clinical data of the patients were reviewed. RESULTS: The three patients were relatively young, ranging in age from 12 to 18 years old. In one eye of each patient, a small traumatic macular hole was observed at the first visit. Visual acuities ranged from 20/100 to 20/40. The macular holes resolved spontaneously 3 to 4 months after the trauma, and final visual acuity improved to 20/20 in all patients. CONCLUSION: Small traumatic macular holes in young patients can resolve spontaneously, and this can be associated with good visual recovery.

Accidents, Traffic↗
PubMed1997

Expression of a mucin-like glycoprotein produced by ocular surface epithelium in normal and keratinized cells.

PURPOSE: We previously characterized a monoclonal antibody (H185) to a mucin-like glycoprotein produced by human ocular surface epithelium. In the current study, we used H185 to investigate the pattern of the mucin-like glycoprotein in normal and keratinized apical cells of the ocular surface epithelium. METHODS: We compared the cell characteristics and the pattern of H185 binding in cytologically and immunohistochemically stained samples of apical cells of conjunctival surface epithelium from 20 normal subjects and six patients before and after treatment for superior limbic keratoconjunctivitis. RESULTS: In the superior bulbar conjunctiva of normal subjects, the intensity with which H185 antibody bound to apical surface epithelial cells varied, with areas of high-, medium-, and low-intensity binding occurring in a mosaic pattern. This mosaic pattern, and presumably expression of the mucin-like glycoprotein, was absent or remarkably reduced in keratinized cells obtained from patients with superior limbic keratoconjunctivitis before treatment. However, the pattern of H185 binding was normal in samples obtained 2 months after the start of treatment for superior limbic keratoconjunctivitis, and cells had recovered their normal small, round appearance. CONCLUSION: When they are keratinized, apical cells of the ocular surface epithelium are altered in appearance and lack the normal mosaic pattern of expression of a mucin-like glycoprotein.

Administration, Topical↗
PubMed1997

Expression of c-fos and c-jun mRNA following transient retinal ischemia: an approach using ligation of the retinal central artery in the rat.

The expression of the proto-oncogenes c-fos and c-jun was examined by in situ hybridization at various timepoints following transient retinal ischemia by means of ligation of the retinal central artery in the rat. Ischemia of 90-minute duration resulted in the degeneration of neurons in both the ganglion cell layer and the inner nuclear layer at 48 hours after reperfusion. The expression of c-fos and c-jun messenger RNA throughout the entire inner nuclear layer was transiently coinduced following 90-minute retinal ischemia with a peak at 1 hour after reperfusion. This expression was also found in the ganglion cell layer at 3 hours after reperfusion. Weak signals for c-fos and c-jun mRNA were observed at 24 hours after reperfusion and returned to near control levels by 48 hours. c-jun protein expression was detected in the ganglion cell layer, the middle of the inner nuclear layer, and optic nerve head at 3 hours, but not 1 hour, after lethal ischemia/reperfusion; however, c-fos protein expression was not detected after reperfusion. Whereas no neuronal degenerative changes were found at 7 days after 30-minute ischemic retina, c-fos and c-jun messenger RNA were also induced at 1 hour postreperfusion. To our knowledge, this study is the first report to show expression patterns of immediate-early genes after retinal ischemia/reperfusion. These results suggest that changes in expression of c-fos and c-jun after transient retinal ischemia are similar to those after transient brain ischemia, and the selective occlusion of the central retinal artery will provide a useful model for studying ischemic neuronal degeneration in vivo in the rat retina.

Animals↗
PubMed1997

Retinal detachment after branch retinal vein occlusion: influence of the type of break on the outcome of vitreous surgery.

BACKGROUND: Branch retinal vein occlusion (BRVO) is occasionally complicated by two types of retinal breaks (retinal holes without vitreous traction or retinal traction tears) that may lead to a rhegmatogenous retinal detachment (RRD). The authors describe surgical results of vitrectomy for RRD after BRVO and investigate whether there is any difference between clinical features or surgical results from eyes with the two types of retinal breaks. PATIENTS AND METHODS: The authors retrospectively studied 25 patients (25 eyes) who underwent vitrectomy for RRD after BRVO. Twelve of 25 eyes (48%) had a detachment secondary to one or more retinal holes (group I), and 13 of the eyes (52%) had one or more retinal tears (group II). RESULTS: Seventeen of the eyes (68%) achieved total retinal reattachment after the initial surgery; 22 (88%) did so by the time of final examination. Patients with retinal holes achieved more favorable final vision than those with retinal tears (P = 0.0391). A higher rate of preoperative macular detachment (P = 0.0112) and a higher rate of recurrent retinal detachment after initial vitrectomy (P = 0.0302) were the factors associated with the reduced final visual acuity in patients with retinal tears. The increased rate of recurrent retinal detachment in patients with retinal tears was associated with a higher rate of existing preretinal neovascular membranes (P = 0.0112) and a trend toward an increased incidence of intraoperative iatrogenic retinal breaks. CONCLUSION: Among patients who undergo vitrectomy for RRD after BRVO, better surgical results are expected in eyes with retinal holes without vitreous traction than in those with retinal traction tears. This difference is thought to be due to the difference in vitreoretinal anatomy between eyes with the two types of retinal breaks.

Aged↗
PubMed1997

The differential osmoregulation and localization of taurine transporter mRNA and Na+/myo-inositol cotransporter mRNA in rat eyes.

We studied the cellular localization and osmotic regulation of taurine transporter (TauT) mRNA in the rat eyes using in situ hybridization. TauT mRNA signals were expressed in the ciliary body, and the outer part of the inner nuclear layer (INL), the outer nuclear layer (ONL) and the inner segment (IS) of the adult rat retina. Chronic hypernatrema, induced by gavaging with 1 ml/100 g body weight of 5% NaCl every other day for 7 days, markedly increased in TauT mRNA in the retina compared with control rats. However, there was little change in TauT mRNA in the eyes in acute hypernatremic state that is induced by single injection of high concentration of NaCl. On the contrary, acute hypernatremic rats displayed markedly elevated Na+/myo-inositol cotransporter (SMIT) mRNA in the retina and the iris-ciliary body and the lens epithelium. Under chronic hypernatremic conditions, there was no significant increase in SMIT mRNA in rat eyes. These findings suggest that TauT mRNA is osmotically regulated in vivo to protect retinal neuronal function, especially against chronic hypernatremic conditions, in contrast to rapid up-regulation of SMIT mRNA in acute hypernatremic rats.

Animals↗