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Biomedical subjects

I Toda

Publications and source records attributed to I Toda.

At least 55 records · Page 3Linked to original sources

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↗

A case of dobutamine-induced coronary arterial spasm with ST-segment elevation.

A 55-year-old Japanese woman demonstrated ST-segment elevation in leads I, aVL, and V3-V6 with chest pain both in an ergometer exercise test and on dobutamine stress echocardiography. Although the baseline coronary arteriogram revealed no organic stenosis, total occlusion of the distal portion of the posterolateral branch of the left circumflex artery was observed during dobutamine infusion with ST-segment elevation and chest pain. This is a rare case of documented dobutamine-induced coronary arterial spasm.

Coronary Vasospasm↗

Effect of manidipine hydrochloride, a calcium antagonist, on isoproterenol-induced left ventricular hypertrophy.

We examined the effect of a calcium antagonist, manidipine hydrochloride, on cardiac hypertrophy and the expression of the atrial natriuretic peptide (ANP), transforming growth factor beta 1 (TGF-beta 1), and extracellular matrix protein genes in rats with isoproterenol-induced cardiac hypertrophy. Rats were continuously infused with saline or isoproterenol (0.5 mg/kg per day) for 7 days using an osmotic minipump. Treatment with manidipine hydrochloride (once a day at 3 mg/kg) began 1 day before minipump implantation and continued until the end of the experiments (each group; n = 6). After treatment, left ventricular weight was measured and mRNA was extracted and analyzed by Northern blot hybridization. Isoproterenol increased left ventricular weight (2.40 +/- 0.04 g/kg; p < 0.01) without increasing blood pressure. ANP, collagen type I and type III, and fibronectin mRNAs were increased 1.5-(p < 0.01), 1.9- (p < 0.01), 2.7- (p < 0.01), and 3.2-fold (p < 0.01), respectively, by isoproterenol infusion. However, TGF-beta 1, collagen type IV, and laminin B1 and B2 mRNA levels were unchanged by isoproterenol. Manidipine hydrochloride prevented isoproterenol-induced left ventricular hypertrophy (2.26 +/- 0.02 g/kg; p < 0.01) and expression of mRNA of ANP (0.9-fold of the control value; p < 0.01), collagen types I (1.1-fold; p < 0.01) and type III (1.6-fold; p < 0.01), and fibronectin (1.1-fold; p < 0.01). Thus, manidipine hydrochloride prevented cardiac hypertrophy and changes in the expression of genes for ANP and interstitial components of extracellular matrix induced by isoproterenol.

Animals↗

SEM study on microvascular changes following implantation of bone morphogenetic protein combined with hydroxyapatite into experimental bone defects.

BMP-HAP complex was implanted into a bone defect in the femur of Wistar-strain rats, and animals were allowed to heal for one to 8 weeks prior to sacrifice. Similar bone defects without BMP-HAP complex served as controls. Osseous healing and microvascular changes, as revealed by plastic microcorrosion castings, were subsequently examined under a scanning electron microscope. One week after implantation, sproutings and congregate sinusoidal capillary plexuses and primary bone trabeculae (woven bone) were observed around and between the BMP-HAP complexes. Control specimens revealed a fine and immature sinusoidal capillary plexus arising from sproutings and elongations of pre-existing blood vessels, but bone formation was not observed. At two weeks, newly-formed trabeculae were observed around and on the surface of the HAPs, and a network of thick, newly-formed vessels was observed in intervening space. At three weeks, networks of newly-formed vessels were observed on the surface of the HAPs, and surrounding newly-formed trabeculae had become thickened. At four weeks, bone defects were filled, and HAP was completely embedded in new bone. At eight weeks, the HAP was fused with new bone, and the boundary between the HAP and new bone was unclear. In comparison with comparable surgically created control bone defects without implanted BMP-HAP complex, BMP apparently stimulates new vascularization. Further, implanted BMP-HAP apparently stimulates undifferentiated mesenchymal cells to differentiate into angioblasts and osteoblasts, or vice versa (dedifferentiation).

Animals↗

Differences in expression of sarcoplasmic reticulum Ca2+-ATPase and Na+-Ca2+ exchanger genes between adjacent and remote noninfarcted myocardium after myocardial infarction.

Although cardiac failure can develop over time after myocardial infarction, the mechanism responsible for this is still unknown. The change of intracellular Ca2+ transport protein, such as sarcoplasmic reticulum (SR) Ca2+-ATPase (SR-Ca2+), Na+-Ca2+ exchanger (Na+-Ca2+), or cardiac phenotypic modulation of contractile protein in noninfarcted myocardium may have a important role. However, the time course in gene expression of sarcoplasmic reticulum (SR) Ca2+-ATPase (SR-Ca2+), Na+-Ca2+ exchanger (Na+-Ca2+), and contractile protein in the adjacent and remote noninfarcted myocardium after myocardial infarction has not been examined. At 1, 3 weeks and 3 months after myocardial infarction, hemodynamics were measured and mRNA of the left ventricle was analyzed. Left ventricular end-diastolic volume and weight increased both with time. Ascites became apparent at 3 months after infarction. SR-Ca2+ mRNA levels in the adjacent noninfarcted myocardium were 0.7- (P<0.01), 0.9- (N.S.), and 0.7-fold (P<0.01) of control, and Na+-Ca2+ mRNA levels were 2.1- (P<0.01), 1.4- (P<0.01), and 0.8-fold (P<0.01) of control, at 1, 3 weeks and 3 months after infarction, respectively. beta-Myosin heavy chain (MHC) mRNA was increased to 2.1- (P<0.01), 1.5- (P<0.01), and 1.4-fold (P<0.01), and alpha-skeletal actin was increased to 2.4- (P<0.01), 3.8- (P<0.01), and 1.6-fold (P<0.01) control levels, at 1 week, 3 weeks and 3 months, respectively. In contrast, alpha-MHC mRNA level was decreased at 1 week and 3 months after infarction. alpha-cardiac actin mRNA level did not change over time after infarction. In the remote non-infarcted myocardium, beta-MHC, alpha-skeletal actin, and Na+-Ca2+ mRNA levels were increased, but SR-Ca2+, alpha-MHC, and alpha-cardiac actin mRNA did not change after infarction. These findings suggest that: (1) intracellular Ca2+ handling system after myocardial infarction may be different between adjacent and remote non-infarcted myocardium: and that (2) both decreased gene expression of SR Ca2+-ATPase and Na+-Ca2+ exchanger in the adjacent non-infarcted myocardium may progress cardiac dysfunction.

Animals↗

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↗

Surgical reconstruction of the ocular surface in advanced ocular cicatricial pemphigoid and Stevens-Johnson syndrome.

PURPOSE: Ocular cicatricial pemphigoid and Stevens-Johnson syndrome often cause ocular damage and blindness not amenable to surgical correction. We present a new surgical technique for reconstructing affected eyes. METHODS: Fourteen eyes of 11 patients with cicatricial keratoconjunctivitis (seven patients with cicatricial pemphigoid and four with Stevens-Johnson syndrome; average age +/- S.D., 55.5 +/- 25.4 years) were treated with a combination of allograft limbal transplantation, amniotic membrane transplantation, and tarsorrhaphy, followed every 15 minutes by artificial tears derived from the patient's blood serum. Eight eyes required concomitant penetrating or lamellar keratoplasty because of corneal opacity. RESULTS: With a mean follow-up of 143 days (range, 10 to 608 days), we achieved successful ocular surface reconstruction in 12 eyes, with minimal recurrence of symblepharon. Failure occurred in two eyes (one each in 9- and 10-year-old boys) that developed corneal infiltration and vascularization. CONCLUSIONS: A combination of allograft limbal transplantation, amniotic membrane transplantation, and tarsorrhaphy, followed by the use of serum-derived tears, can reconstruct the ocular surface in most cases. Although in this study the follow-up period was short and relatively few patients were studied, this approach appears to offer an alternative to keratoprosthesis for treating severe cicatricial keratoconjunctivitis with dry eye.

Adult↗

Hydroxypropyl methylcellulose for the treatment of severe dry eye associated with Sjögren's syndrome.

Our purpose was to evaluate the efficacy of a new formulation of methylcellulose, preservative-free 0.5% hydroxypropyl methylcellulose (HPMC), for the treatment of dry eye. In the clinical part of our study, two groups of dry-eye patients, those with Sjögren's syndrome (SS) and those without (non-SS), were treated topically with 0.5% HPMC and evaluated for symptoms, ocular surface vital staining, tear breakup time (BUT), and tear evaporation rate from the ocular surface at 40% ambient humidity (TEROS40). In the in vivo part of the study, rose bengal uptake was measured in human conjunctival epithelial cells, which were cultured and incubated with or without 0.5% HPMC. Although symptoms improved in both groups, rose bengal and fluorescein staining and BUT improved significantly only in the SS group. TEROS40 increased for 30 min after instillation of 0.5% HPMC, but not after use of 0.1% sodium hyaluronate or saline-based artificial tears. Rose bengal uptake by cultured conjunctival epithelial cells was blocked by 0.5% HPMC. These findings suggest that 0.5% HPMC provides long coverage of and protection for the ocular surface. Patients with severe dry eye, such as in SS, are good candidates for this treatment.

Adult↗

Corneal temperature in patients with dry eye evaluated by infrared radiation thermometry.

AIMS: The corneal temperature change following each blink was investigated in patients with dry eye using an infrared radiation thermometer. METHODS: Twenty patients with dry eye and 20 normal controls were enrolled in this study. Subjects kept their eyes open for 10 seconds without blinking and corneal temperature was measured every second with a recently improved infrared radiation thermometer. RESULTS: In the 20 patients with dry eye, corneal temperature change after keeping the eye open for 10 seconds was 0.21 (SD 0.06) degree C while it was 0.61 (0.28) degree C in the 20 normal patients (p = 0.0001). In an exponential equation, the inclination of the slope of a patient with dry eye was smaller than the normal. The correlation coefficient was r = 0.79 (0.16) in patients with dry eye and r = 0.90 (0.07) in normal patients. The mean K value of patients with dry eye was 0.20 (0.13)/second and that of normal subjects was 0.31 (0.19)/second (p = 0.03). CONCLUSION: Findings demonstrate the usefulness of this thermometer for measuring corneal temperature in the evaluation of dry eye. Decrease in corneal temperature with each blink in patients with dry eye was smaller than in normal subjects.

Adolescent↗

Allergic conjunctivitis and dry eye.

AIMS: Differential diagnosis of allergic conjunctivitis or dry eye is sometimes very difficult to diagnose by symptoms and clinical examination alone, especially in older patients. It was hypothesised that clinically allergic patients who were serum antigen specific IgE negative were candidates for dry eye. METHODS: Sixty patients were studied prospectively who were clinically diagnosed with allergic conjunctivitis by their itchy sensation and papilla formation of conjunctiva. They consisted of 30 serum antigen specific IgE positive and 30 IgE negative patients, with no significant differences in age. Dry eye examination and serum total IgE were performed on these two groups. RESULTS: No significant differences were seen between the two groups with regard to age (p = 0.76) and sex ratio. The antibody negative group had lower Schirmer's test scores (p = 0.002), lower tear clearance (p = 0.0001), lower tear function index (p = 0.0001), and lower serum total IgE (p = 0.04) than the antibody positive group. CONCLUSION: This study suggests that the evaluation of serum antigen specific IgE and tear dynamics are important for the differential diagnosis of patients with allergic conjunctivitis and dry eye. Clinically diagnosed allergic conjunctivitis with negative serum antigen specific and total IgE can be one form of dry eye.

Adolescent↗

Increase in corneal epithelial cell size with extended wear soft contact lenses depends on continuous wearing time.

AIM: Although 1 week of continuous wearing time (CWT) is recommended for extended wear soft contact lenses (EWSCL), there have been few studies concerning the appropriateness of this or other CWTs. The current study was undertaken to examine the effect of various CWTs on the cornea by observing the corneal epithelium. METHODS: Specular microscopy was used to evaluate corneal epithelial changes induced by EWSCL in 19 myopic patients (24.0 (SD 6.7) years), divided into four groups: CWT of 0, 1, 3, and 6 days. RESULTS: The initial mean cell area was 628.2 (13.4) micron2. After 6 months this was 629.3 (28.6) micron2 for daily wear (ns), and 660.0 (40.9) micron2, 727.7 (49.6) micron2 (p < 0.01), and 815.5 (67.2) micron2 (p < 0.01) for CWT of 1, 3, and 6 days, respectively (p < 0.01). CONCLUSION: These findings indicate that the corneal epithelium changes proportionally with the CWT; the shorter the CWT, the better the epithelial morphology. This suggests that the CWT for EWSCL be minimised, so as to reduce the potential risk of contact lens related problems.

Adult↗

Excimer laser photorefractive keratectomy for patients with contact lens intolerance caused by dry eye.

AIMS/BACKGROUND: To evaluate epithelial wound healing and visual outcome of excimer laser photorefractive keratectomy (PRK) performed on high myopic eyes with contact lens intolerance due to dry eye. METHODS: PRK was performed on two groups of patients with non-Sjogren's dry eye: group A (-6 D to -9.5 D, 11 patients, 17 eyes) and group B (-11.5 D to -19.5 D, 11 patients, 16 eyes) in an attempt to eliminate the use of contact lenses (CL). The intended correction was full in group A and 10 D in group B. RESULTS: Uncorrected visual acuity in group A was better than 20/40 in 12 (80.0%) of 15 eyes at 6 months and in 10 (90.9%) of 11 eyes at 1 year. Fourteen (92.8%) of 17 eyes in group A and four (25.0%) of 16 eyes in group B achieved refraction within plus or minus 1 D of the intended correction at 6 months. Re-epithelialisation was complete in 4 days, and epithelial cell area and permeability returned to the preoperative level within 1 month in all cases. All patients in group A were able to eliminate CL, whereas in group B, one patient needed spectacles for residual myopia and two patients resumed CL use because of regression. One eye with severe subepithelial scar formation and one eye with macular haemorrhage were observed in group B. CONCLUSION: Our results suggest that PRK is effective for patients with high myopia (-6 D to approximately -10 D) and CL intolerance due to dry eye. Further studies are required to improve predictability and to prevent complications in PRK for very high myopia (> -10 D).

Adult↗

Retrospective survey of a link between cat and dog antigens and allergic conjuctivitis.

This retrospective 3-year study was designed to determine (a) which antigen positive patients were found in greater numbers, (b) whether the patients who were positive for cat or dog antigen-specific IgE were also positive for other antigens, and (c) whether the number of patients with allergic conjunctivitis increased during a particular time of the year. A total of 762 patients were diagnosed with allergic conjunctivitis including 107 cat-positive and/or dog-positive patients. Cat-positive patients were more prevalent than dog-positive patients, (p < 0.001). All but 2 patients were positive for other antigens, indicating a strong link between the animal antigens and other antigens. Cat and dog allergy increased in spring and early summer.

Adolescent↗