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Biomedical subjects

H Fujishima

Publications and source records attributed to H Fujishima.

At least 19 recordsLinked to original sources
PubMed2000

Association of preoperative tear function with surgical outcome in severe Stevens-Johnson syndrome.

OBJECTIVE: To retrospectively study the surgical outcome in severe Stevens-Johnson syndrome (SJS). DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Twenty-nine eyes of patients with severe SJS associated with total conjunctivalization were examined. INTERVENTION: Preserved human amniotic membrane grafting and keratolimbal allograft transplantation was performed. Intensive immunosuppression and epithelial management were continued postoperatively. MAIN OUTCOME MEASURES: Successful ocular surface reconstruction was determined by epithelialization with corneal epithelium. The association between surgical outcome and preoperative tear function was studied. RESULTS: The ocular surface was successfully covered by corneal epithelium in 13 eyes (44.8%). The mean corrected visual acuity recovered from 0.0039 to 0.017. Persistent epithelial defect was the most common complication. Eyes with successful ocular surface reconstruction had significantly better preoperative Schirmer's test values (P = 0.025) and tear clearance rates (P = 0.043) than those that failed. CONCLUSIONS: In patients with severe SJS, preoperative tear function significantly influenced surgical outcome. Eyes with Schirmer's test value of >10 mm have a greater chance of successful ocular surface reconstruction.

Adolescent↗
PubMed2000

Trabeculectomy with mitomycin C for post-keratoplasty glaucoma.

AIM: To investigate the effect of trabeculectomy with and without mitomycin C in post-keratoplasty glaucoma. METHODS: A retrospective study was performed on patients who underwent trabeculectomy for glaucoma after penetrating keratoplasty. 34 eyes of 32 patients were included in this study. 26 eyes received trabeculectomy with mitomycin C and eight eyes without mitomycin C. The procedure was deemed successful if the intraocular pressure was maintained below 21 mm Hg with or without use of additional antiglaucoma medication (mean follow up time 22.3 (SD 10.3) months). RESULTS: At the last examination trabeculectomy was successful in 19 of 26 eyes (73.0%) with mitomycin C (+) and two of eight (25.0%) without (p=0.0219). When the prognosis was analysed by Kaplan-Meier curve, the mitomycin C (+) group showed a better prognosis (p=0.0182). Mean intraocular pressure and average number of glaucoma medications improved in the group with mitomycin C without severe side effects on the graft. Graft rejection after trabeculectomy was seen in two eyes in the mitomycin C group. Final graft clarity rate was 69.2% (18/26) in the mitomycin C (+) group and 37.5% (3/8) in the mitomycin C (-) group. Complications such as persistent epithelial defect, cystoid macular oedema, choroidal detachment, leakage from bleb were seen in four eyes in the mitomycin C (+) group and in one eye in the mitomycin C (-) group. CONCLUSIONS: Trabeculectomy with mitomycin C showed better results for glaucoma following keratoplasty.

Adult↗
PubMed1999

Cytosolic phospholipase A2 is essential for both the immediate and the delayed phases of eicosanoid generation in mouse bone marrow-derived mast cells.

We have used mice in which the gene for cytosolic phospholipase A2 (cPLA2) has been disrupted to demonstrate the absolute requirement for cPLA2 in both the immediate and the delayed phases of eicosanoid generation by bone marrow-derived mast cells. For the immediate phase, quantitative analysis of the products of the 5-lipoxygenase pathway showed that gene disruption of cPLA2 prevented the provision of arachidonic acid substrate for biosynthesis of proximal intermediates. By analogy, we conclude that arachidonic acid substrate was also not available to prostaglandin endoperoxide synthase 1 in the immediate phase of prostaglandin (PG) D2 generation. These defects occurred with two distinct stimuli, stem cell factor and IgE/antigen, which were, however, sufficient for signal transduction defined by exocytosis of beta-hexosaminidase. Whereas cPLA2 is essential for immediate eicosanoid generation by providing arachidonic acid, its role in delayed-phase PGD2 generation is more complex and involves the activation-dependent induction of prostaglandin endoperoxide synthase 2 and the supply of arachidonic acid for metabolism to PGD2.

Animals↗
PubMed1999

v-src induces cisplatin resistance by increasing the repair of cisplatin-DNA interstrand cross-links in human gallbladder adenocarcinoma cells.

Activation of Src, which has an intrinsic protein tyrosine kinase (PTK) activity, has been demonstrated in human solid tumors, such as colorectal and breast cancers. To investigate the role of activated Src in drug resistance, we evaluated the effect of v-src on the resistance to various anti-cancer drugs using v-src-transfected HAG-1 human gallbladder adenocarcinoma cells. Compared with parental or mock-transfected HAG-1 cells, v-src-transfected HAG/src3-1 cells showed a 3.5-fold resistance to cis-diamminedichloroplatinum (II) (CDDP) but not to doxorubicin, etoposide or 5-fluorouracil. By contrast, activated H-ras, which acts downstream of src, failed to induce resistance to either of these drugs. Furthermore, wortmannin, a phosphatidylinositol (PI) 3-kinase inhibitor, and H7, a protein kinase C (PKC) inhibitor, did not alter CDDP resistance. Evaluation of the kinetics of the removal of DNA interstrand cross-links (ICLs), measured by alkaline elution, showed a significant increase in this removal in HAG/src3-1 cells as compared with mock-transfected cells, though no differences were found in the formation of DNA ICLs between these cell lines. CDDP resistance in v-src-transfected cells was reversed, if not completely, by either herbimycin A or radicicol, specific inhibitors of Src-family PTKs, suggesting that Src tyrosine kinase activity induces CDDP resistance. Moreover, significant reduction in the repair of CDDP-induced DNA ICLs was observed upon treatment with radicicol. The intracellular glutathione content and mRNA expression of topoisomerase II and metallothionein were virtually identical between these cell lines, except for topoisomerase I mRNA. Our data strongly suggest that the ability of activated src, but not ras, to induce CDDP resistance is mediated by augmentation of DNA repair through Src to downstream signal-transduction pathways distinct from either the Ras, PI 3-kinase or PKC pathway.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1999

Pregnanes and pregnane glycosides from Hoya carnosa.

Eleven pregnanes were isolated from the hydrolysate of the CHCl3 extract fractionated from the caules of Hoya carnosa. Among these, six pregnanes, including 19-acetoxydigipurpurogenin II, were new, and their structures were elucidated. The structures of twenty new pregnane tetraosides and pentaosides, named hoyacarnosides A-T, besides three known ones from the CHCl3 extract, were determined.

Carbohydrate Sequence↗
PubMed1998

Interferon-alpha and -gamma inhibit the growth and neoplastic potential of v-src-transformed human epithelial cells by reducing Src tyrosine kinase activity.

To investigate whether interferons (IFNs) selectively suppress the growth of solid tumor cells with elevated protein tyrosine kinase (PTK) activity, we evaluated the effect of recombinant IFN-alpha2a and IFN-gamma on the proliferative and neoplastic potentials triggered by p60v-src using v-src-transformed HAG-1 human epithelial cells. When compared with control cells harboring the pSV2neo gene, the monolayer growth of v-src-transformed cell lines was inhibited by both recombinant IFNs, in a dose-dependent manner, whereas growth of ras-transfected cell lines was not affected. Moreover, IFNs markedly reduced the clonogenic growth of v-src-transformed cells in soft-agar rather than monolayer growth, suggesting the preferential activity of IFNs on anchorage-independent growth. Pretreatment of cells with Src or the Src-like PTK inhibitor herbimycin A or radicicol, alleviated dose-dependently the growth-inhibitory activity of IFN-alpha2a against v-src-transformed cells, suggesting that IFNs may share a common inhibitory pathway with Src PTK inhibitors. Accordingly, like herbimycin A, IFNs were found to reduce tyrosine phosphorylation of p60v-src and suppressed in vitro p60v-src kinase activity in v-src-transformed cells. Our data, together with the fact that IFNs inhibit the growth potential driven by Src but not by activated Ras, suggest that inhibition of signal transduction pathway through Src to downstream transduction events may be a primary mechanism of IFN-induced anti-prolifeative and anti-tumoral activity.

Adenocarcinoma↗
PubMed1998

Allergic conjunctivitis as a risk factor for regression and haze after photorefractive keratectomy.

PURPOSE: To analyze the relation between allergic conjunctivitis and the results of photorefractive keratectomy performed with an excimer laser in myopic eyes. METHODS: Fifty-seven myopic eyes in 57 Japanese patients were classified into three groups: a normal group (30 eyes of 30 patients), a treatment group composed of eyes with allergic conjunctivitis that were treated with fluorometholone and cromolyn sodium eyedrops from month 3 until the end of the 12- to 18-month follow-up period (16 eyes of 16 patients), and a no-treatment group composed of eyes with allergic conjunctivitis that received no allergic treatment until the end of the follow-up period (11 eyes of 11 patients). Preoperative and postoperative examinations included evaluation of corrected and uncorrected visual acuity and grading of corneal haze. RESULTS: In the no-treatment group, the mean corneal haze score +/- SD of 0.8 +/- 0.98 was significantly greater than the normal group score of 0.38 +/- 0.49 (P = .02). There was no significant difference in the haze score between the treated and normal groups. A refractive outcome of +/- 1 diopter was obtained in 30 (100%) of the 30 patients in the normal group, 15 (93.8%) of 16 patients in the treatment group, and four (36.4%) of the 11 patients in the no-treatment group. Visual acuity was 20/40 or better after photorefractive keratectomy in 30 patients (100%) in the normal group, 15 patients (93.8%) in the treatment group, and six patients (54.5%) in the no-treatment group. CONCLUSION: These findings suggest that untreated allergic conjunctivitis is a significant risk factor for haze and myopic regression after photorefractive keratectomy.

Adult↗
PubMed1998

Trabeculectomy with the use of amniotic membrane for uncontrollable glaucoma.

Although trabeculectomy is an established surgical technique for glaucoma, in some cases it does not achieve a good filtering effect despite the use of mitomycin-C (MMC). The authors have developed a new surgical technique for uncontrollable glaucoma that uses amniotic membrane to prevent postoperative adhesion of conjunctiva and sclera. They performed trabeculectomy with a limbal-based conjunctival flap using 0.4 mg/ml of MMC for 2 minutes. Amniotic membrane was then placed under the scleral flap and sutured using 10-0 nylon. Among 14 eyes of 13 patients who underwent this procedure, intraocular pressure was controlled to less than 20 mm Hg after surgery in 13 eyes, including 3 eyes that underwent a second surgery with the same technique and 2 eyes that underwent laser trabeculoplasty. The authors' results suggest that this technique is efficacious for the reduction of intraocular pressure in high-risk glaucoma patients.

Adult↗
PubMed1998

Respiratory syncytial virus-induced interleukin-4 production by human conjunctival epithelial cells contributes to allergy: preliminary study.

PURPOSE: We previously reported allergic conjunctivitis was associated with a local pattern of cytokines and identified respiratory syncytial virus (RSV) in the conjunctival epithelium, in patients with allergic conjunctivitis. We hypothesized that RSV infected the normal conjunctival epithelium and produced interleukin-4 (IL-4), causing an allergic reaction. To determine this event, we studied production of IL-4 by human conjunctival epithelial cells, after infection with RSV. METHODS: Conjunctival samples were collected with a special brush and were challenged with 5 x 10(6) pfu/ml of live RSV. RSV infection was detected by immunocytochemical study and RT-PCR. HLA-DR antigen was expressed by flow cytometry. IL-4 was assayed by a sandwich ELISA. RESULTS: Immunocytochemical study and RT-PCR showed that RSV infected the conjunctival epithelial cells. HLA-DR was demonstrated in the RSV-infected conjunctival epithelial cells. Average concentrations of IL-4 in culture supernatants in infected cells were 3.8 +/- 1.8, 3.6 +/- 1.1, and 5.4 +/- 1.8 pg/ml at 24, 48, and 72 h, respectively. Levels in non-infected cells were 0.33 +/- 0.0, 0.59 +/- 0.69, and 0.4 +/- 0.22 pg/ml, respectively (p > 0.001). CONCLUSION: Findings suggest that the expression of IL-4 is associated with intracellular infection by RSV in conjunctiva. With our former reports, RSV infection in conjunctival epithelial cells can be suggested as one of the possible environmental pathogens of allergic conjunctivitis.

Adolescent↗
PubMed1997

Lacrimal punctal occlusion for the treatment of superior limbic keratoconjunctivitis.

PURPOSE: To test the hypothesis that superior limbic keratoconjunctivitis is caused by insufficient tear supply to the superior keratoconjunctiva. METHODS: We used cautery and sutures to permanently occlude the lacrimal puncta of 11 patients (22 eyes) with superior limbic keratoconjunctivitis for whom topical treatment was ineffective. RESULTS: All 11 patients (22 eyes) responded favorably to lacrimal punctal occlusion. After lacrimal punctal occlusion, rose bengal and fluorescein staining (both on a scale of 0 [no staining] to 9 [complete staining]) were reduced (mean +/- SD, 2.7 +/- 1.6 to 1.1 +/- 1.8 and 1.4 +/- 1.2 to 0.4 +/- 0.8, respectively). Impression cytology disclosed improvement of squamous metaplasia in the superior conjunctiva as well as increased goblet cells in nine of 13 eyes (69%) examined. Subjective symptoms improved in all 22 eyes (100%). CONCLUSIONS: Improvement of local tear deficiency to the superior limbic portion by punctal occlusion was an effective treatment in this small series. Superior limbic keratoconjunctivitis might be caused by the insufficient local tear supply.

Adult↗
PubMed1997

Use of high-speed, high-resolution thermography to evaluate the tear film layer.

PURPOSE: To evaluate the tear film layer in patients with dry eye and in normal subjects by measuring the corneal temperature with infrared radiation thermography. METHODS: One eye of each of 13 patients with dry eye and one eye of each of seven normal subjects were evaluated randomly. The corneal temperature was measured continuously with a recently improved infrared radiation thermography technique. We calculated the k value, which reflected the steepness of the corneal temperature change. The bigger the k value was, the more rapid was the decrease in corneal temperature, and this was directly related to increased evaporation. RESULTS: With normal blinking, the mean k value for patients with dry eye (5.6 +/- 2.9 per second) was significantly less than that in the control subjects (9.3 +/- 5.0 per second; P < .05). Keeping the eyes open after closing the eyes significantly decreased the k values compared with normal blinking in both groups (P < .05). CONCLUSIONS: Our findings demonstrate the usefulness of this method of measuring corneal temperature to evaluate the tear film layer. High-speed, high-resolution thermography detected subtle changes in corneal temperature with enhanced sensitivity and spatial and temporal resolution. We found that the mean k value, and therefore the rate of decline in corneal temperature in patients with dry eye, was significantly less than that in normal subjects. The k value may therefore reflect tear film layer stability. The measurement of the changes in the corneal temperature can thus give us valuable information on the tear film layer.

Adult↗
PubMed1997

Elevated levels of substance P in tears of patients with allergic conjunctivitis and vernal keratoconjunctivitis.

BACKGROUND: Recent studies have suggested that the nervous system may participate in inflammatory processes. Substance P (SP) acts as a chemical mediator as well as a neurotransmitter. OBJECTIVE: In order to clarify the pathogenesis of ocular allergic diseases, we assessed the concentration of SP in tears. METHODS: Using a highly sensitive and specific double-antibody enzyme immunoassay (EIA), we determined the SP concentration in tears of 10 patients with seasonal allergic conjunctivitis, 10 with atopic dermatitis without keratoconjunctivitis (AD), 13 with vernal keratoconjunctivitis (VKC) and 65 normal controls. Giemsa's staining for brush cytology samples and histocytological study by immunocytochemical staining of giant papillary conjunctival cells from VKC and normal controls was conducted. RESULTS: The mean SP level was low in the normal controls and AD, whereas patients with seasonal allergic conjunctivitis and VKC showed significant elevation of SP (P < 0.01). Brush cytology samples showed conjunctival epithelial cells with lymphocytes, neutrophils and eosinophils that were not seen in normal subjects. Histocytological examination demonstrated SP positive cells in the conjunctiva of patients with VKC, but not in normal controls. CONCLUSION: This study suggests that the increased level of SP in tears may contribute to the pathogenesis and severity of ocular allergic diseases.

Adolescent↗
PubMed1997

Characterization of cytokine mRNA transcripts in conjunctival cells in patients with allergic conjunctivitis.

PURPOSE: The host response to allergens appears to be regulated by specific patterns of local cytokine production. More than 20,000 conjunctival superficial cells were collected with a special brush, a smaller version of the Cytobrush used in cervical cytology, from the upper palpebral conjuntiva. METHODS: Samples were obtained by cytology brush from seven patients with allergic conjunctivitis and from seven healthy volunteers. Giemsa staining, immunocytochemistry, and flow cytometric analysis were performed. Cytokine gene expression was assayed by the reverse-transcription-polymerase chain reaction method. RESULTS: Giemsa staining of cytocentrifuged preparations from patients with allergic conjunctivitis showed conjunctival epithelial cells with lymphocytes, mast cells, and eosinophils. In an immunohistochemical study, a few CD3- and CD4-bearing cells, but not CD20- and CD14-bearing cells, were seen in patients. In 82.6 +/- 17% of the samples obtained from allergic patients, HLA-DR was present, but it was present in only 34.2 +/- 17.8% of samples from control subjects (P = 0.0001) using flow cytometric analysis. Steady state transcripts of mRNA for cytokines were analyzed with RT-PCR in conjunctival cell samples, and results showed that samples from allergic conjunctivitis expressed increased transcripts of interleukin 4 and interleukin 13 but virtually no interleukin 2 or interferon-gamma; six samples from seven healthy subjects expressed no interleukin 2, interleukin 4, interleukin 13, or interferon-gamma transcripts. CONCLUSIONS: These results suggest that the clinical features of allergic conjunctivitis in humans are associated with a specific local pattern of proinflammatory cytokine expression.

Adolescent↗
PubMed1997

Inhibition by 5-fluorouracil of ERCC1 and gamma-glutamylcysteine synthetase messenger RNA expression in a cisplatin-resistant HST-1 human squamous carcinoma cell line.

Pretreatment of 5-fluorouracil (5-FU), but not posttreatment, has been shown to augment the cytotoxicity of cisplatin (CDDP) or even circumvent CDDP resistance by inhibiting repair of platinum-DNA interstrand crosslinks as well as by reducing the cellular glutathione (GSH) contents in CDDP-resistant HST-1/CP0.2 human squamous carcinoma cells. Because exogenous thymidine, which compensates for 5-FU-mediated inhibition of de novo DNA synthesis via salvage pathway, did not affect this schedule-dependent synergism, the modulatory effect of 5-FU on CDDP resistance would be attributed to the 5-FU-induced RNA damage. We therefore examined the effect of 5-FU on the steady-state levels of messenger RNA (mRNA) of a human excision repair gene ERCC1 and gamma-glutamylcysteine synthetase (gamma-GCS) gene coding for a rate-limiting enzyme for GSH synthesis. The HST-1/ CP0.2 cells were found to have significantly more mRNA expression of these respective genes than do parental HST-1 cells. In these cells, 5-FU pretreatment progressively inhibited mRNA expression of both ERCC1 and gamma-GCS after removal of 5-FU, without affecting glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA. A maximal mRNA suppression was observed at 48 h posttreatment. Such 5-FU-induced suppression of mRNA transcripts of these genes seems to be consistent with its inhibitory activity on DNA repair capacity and cellular GSH contents. In contrast, 5-FU did not reduce the level of glutathione-S-transferase-pi (GST-pi) or DNA topoisomerase 1 mRNA. Although not convinced, our data suggest that 5-FU, when incorporated into RNA, may inhibit both GSH synthesis and repair of platinum-DNA adducts by downregulating the ERCC1 and gamma-GCS genes, thereby enhancing antitumor activity of CDDP and reversing resistance to CDDP in HST-1/CP0.2 cells.

Antimetabolites, Antineoplastic↗
PubMed1997

Effects of artificial tear temperature on corneal sensation and subjective comfort.

PURPOSE: Cooling reduces acute inflammation and local nerve sensation. We investigated the relationship between artificial tear temperature, ocular surface sensation, and patient comfort. METHODS: We placed preservative-free artificial tears and eye mask stored at four temperatures (36 degrees C, 25.2 degrees C, 4 degrees C, and -10 degrees C) in the right eyes of 24 normal subjects, whose left eyes served as controls. Corneal and conjunctival sensations were measured and corneal temperature was recorded. Comfort was reported on a 7-point scale. RESULTS: Corneal temperature was significantly lowered with all temperature artificial tears and frozen eye mask (p < 0.001 for each temperature relative to the previous one). Aesthesiometer readings were inversely correlated with corneal temperature (r = -0.45, p = 0.0005), decreasing with lower temperatures, reaching 2.0 +/- 1.3 g/mm2 (p = 0.001) for the mask. Conjunctival sensation reacted similarly and was well correlated with both corneal temperature (r = 0.43, p = 0.0009) and corneal sensation (r = 0.39, p = 0.006). Treatments provided relief, with the 4 degrees C tears being the most comfortable (p = 0.0001). CONCLUSION: Although there may still be some biases, cooled artificial tears provide relief to the eye by the mechanism of reduced corneal and conjunctival sensation.

Administration, Topical↗
PubMed1996

A heparin-sensitive phospholipase A2 and prostaglandin endoperoxide synthase-2 are functionally linked in the delayed phase of prostaglandin D2 generation in mouse bone marrow-derived mast cells.

BALB/cJ mouse bone marrow-derived mast cells (BMMC) developed with interleukin (IL)-3 can be stimulated by c-kit ligand (KL) in the presence of IL-10 and IL-1beta for sequential immediate and delayed generation of prostaglandin (PG) D2 through utilization of constitutive prostaglandin endoperoxide synthase (PGHS) -1 and induced PGHS-2, respectively (Murakami, M., Matsumoto, R., Austen, K. F., and Arm, J. P. (1994) J. Biol. Chem. 269, 22269-22275). We now report that BALB/cJ BMMC stimulated with KL + IL-10 + IL-1beta also exhibit the biphasic release of [3H]arachidonic acid with an immediate phase over the first 10 min followed by a delayed phase from 2 to 7 h. The delayed phase of arachidonic acid release and of PGD2 generation was inhibited by heparin, which concomitantly released a phospholipase (PL) A2 from the cells into the supernatant. Both dexamethasone and a type II PLA2 inhibitor, 12-epi-scalaradial, suppressed delayed-phase PGD2 generation at concentrations that did not affect immediate eicosanoid generation. Transcripts for type IIA PLA2, as assessed by reverse transcription-polymerase chain reaction, were progressively induced in BALB/cJ BMMC treated for 2 to 7 h with KL + IL-10 + IL-1beta; the induction of these transcripts was down-regulated by 10(-6) M dexamethasone. The expression of steady-state transcripts and protein for cytosolic PLA2 (cPLA2) did not change. PGHS-2-dependent delayed-phase PGD2 generation elicited by IgE-dependent activation of BALB/cJ BMMC primed with KL + IL-10 was also accompanied by the induction of type IIA PLA2 transcripts and was suppressed by heparin, with concomitant release of PLA2 into the supernatant. However, both the direct, cytokine-stimulated and the cytokine-primed, IgE-dependent, delayed-phase PGD2 generation occurred in BMMC from C57BL/6J mice, which have a natural disruption of the type IIA PLA2 gene. Thus, kinetic, pharmacologic, and genetic analyses suggest that an inducible, heparin-sensitive PLA2, rather than cPLA2, provides arachidonic acid to concomitantly induced PGHS-2 for delayed-phase PGD2 biosynthesis in activated BMMC. Furthermore, this heparin-sensitive PLA2 likely represents a novel PLA2 or a new function for a known low molecular weight PLA2.

Animals↗