Biomedical subjects

D Kurosaka

Publications and source records attributed to D Kurosaka.

36 records · Page 2Linked to original sources

PubMed1998

Cell electrophoretic mobility and glycerol lysis of human erythrocytes in various diseases.

Using an automated cell electrophoresis system equipped with an image processor, we studied electrophoretic mobilities of erythrocytes of healthy donors and of patients suffering from systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), hypergammaglobulinemia and diabetes mellitus (DM). On average, erythrocytes from SLE patients showed mean electrophoretic mobilities (EPM) which were significantly lower (p < 0.005) than the EPM of red blood cells of normal donors. Evaluation of mean EPM and standard deviations revealed that three groups of SLE patients could be distinguished regarding the electrophoretic behavior of their erythrocytes. Some patients had red blood cells with normal EPM, others had erythrocytes with significantly reduced EPM, and a third group appeared to have both kinds of erythrocytes. In addition, erythrocytes of various SLE patients showed enhanced resistance to lysis by glycerol and their membranes contained less quantities of band 3 proteins.

Arthritis, Rheumatoid↗

PubMed1998

Three year prospective, randomized evaluation of intraocular lens implantation through 3.2 and 5.5 mm incisions.

PURPOSE: To compare the long-term clinical results of two small incision cataract surgery procedures. SETTING: Seven centers in Japan. METHODS: Two hundred eyes were randomly assigned to receive a silicone intraocular lens (IOL) through a 3.2 mm incision or a poly(methyl methacrylate) (PMMA) IOL through a 5.5 mm incision. Except for incision size and implantation technique, the surgical methods were identical. Uncorrected and corrected visual acuity, keratometry, flare-cell intensity, specular microscopy, and neodymium:YAG (Nd:YAG) laser posterior capsulotomy rate were analyzed up to 3 years after surgery. RESULTS: Eyes in the 3.2 mm incision group had significantly better uncorrected and corrected visual acuity in the early postoperative period and lower aqueous flare intensity immediately after surgery, but these differences disappeared after the first postoperative month. However, surgically induced astigmatism was significantly less in the 3.2 mm incision group than in the 5.5 incision group throughout the study. The Nd:YAG laser capsulotomy rate was higher in the silicone IOL group (23.5% at 3 years postoperatively) than in the PMMA IOL group (18.4%) but the difference was not statistically significant. CONCLUSION: Smaller incision cataract surgery led to early recovery of visual function in the short term and less induced astigmatism in the long term.

Aged↗

PubMed1998

Transforming growth factor-beta 1 promotes contraction of collagen gel by bovine corneal fibroblasts through differentiation of myofibroblasts.

PURPOSE: To determine whether the ability of transforming growth factor-beta (TGF-beta) to influence the contractile activity of corneal fibroblasts depends on their differentiation into myofibroblasts. METHODS: Bovine corneal fibroblasts were cultured on collagen gel in MED 5 medium (F-12 nutrient mixture supplemented with 5% fetal bovine serum) with or without TGF-beta 1 (0.01-10 ng/ml). To evaluate the corneal fibroblast-derived contraction of collagen gel, the thickness of the gel was measured daily for 6 days. The total number of cells on the gel was counted with a Coulter counter. The detection of alpha-smooth muscle actin (alpha-SMA); a marker for myofibroblasts, on these cells was performed immunocytochemically by using a mouse monoclonal antibody against alpha-SMA. The number of myofibroblasts (alpha-SMA-positive cells) was determined. RESULTS: The control gels containing bovine corneal fibroblasts that were cultured with the MED 5 medium alone significantly contracted to 72.3 +/- 1.2% of their original thickness after 6 days. TGF-beta 1 increased the contraction of collagen gel mediated by bovine corneal fibroblasts in a dose-dependent manner. Approximately 0.2% of the cells on the control gels cultured with MED 5 medium alone were alpha-SMA positive. TGF-beta 1 significantly increased the expression of alpha-SMA in a dose-dependent manner. There was no significant correlation between the thickness of the collagen gel and the total number of cells. However, there was a significant negative correlation between the thickness of collagen gel and the number of myofibroblasts. CONCLUSIONS: TGF-beta 1 increased the contractile activity of bovine corneal fibroblasts and their ability to differentiate into myofibroblasts. Because contractile activity was correlated with differentiation, the influence of TGF-beta 1 on corneal fibroblast-induced collagen gel contraction may depend on the promotion of myofibroblast differentiation.

Actins↗

PubMed1997

Evaluation of a zonal-progressive multifocal intraocular lens.

PURPOSE: To determine the clinical usefulness of a five-zone refractive multifocal intraocular lens. METHODS: After more than 1 year of follow-up, we evaluated the visual function of 22 patients (36 eyes) who had received the MPC-25NB intraocular lens for distance and near visual acuity, kinetic visual acuity, and near contrast sensitivity, and for patient satisfaction. RESULTS: Of 31 study eyes with less than 1.5 diopters of preoperative keratometric astigmatism, 28 (90.3%) achieved an uncorrected distance visual acuity of 20/40 or better; best-corrected distance visual acuity was 20/20 or better in 31 (86.1%) of 36 eyes. Near visual acuity with distance correction was 20/40 or better in 20 (60.6%) of 33 eyes. Kinetic visual acuity in these patients was comparable to that in patients with monofocal intraocular lenses. Distance visual acuity and near contrast sensitivity were below normal or within the low normal range. There was no significant difference in contrast visual acuity measured by variable contrast visual acuity charts between MPC-25NB and monofocal intraocular lens-implanted eyes (P > .05). Four (22.2%) of 18 patients did not require spectacles when the intraocular lens was implanted for emmetropia. Despite some complaints about near or night vision, all patients expressed satisfaction. CONCLUSIONS: The MPC-25NB lens provides a level of distance vision comparable to that of a monofocal intraocular lens and a useful level of near visual acuity without spectacles. However, we should carefully evaluate the indication for use of MPC-25NB in patients who require good near vision or night vision.

Adult↗

PubMed1997

Elschnig pearl formation along the posterior capsulotomy margin after neodymium:YAG capsulotomy.

PURPOSE: To determine the incidence of Elschnig pearl formation along the capsulotomy margin (string of pearls) after neodymium:YAG (Nd:YAG) laser posterior capsulotomy and to elucidate its clinical features, predisposing factors, effect on visual function, and association with additional capsulotomy. SETTING: Keio University Hospital, Tokyo, Japan. METHODS: The records of 418 eyes that had had Nd:YAG posterior capsulotomy after cataract surgery were retrospectively reviewed. Of those, 315 were excluded for short follow-up (fewer than 12 months) or insufficient clinical examination data. In the remaining 103 eyes, the incidence of string of pearls was calculated, and its clinical features, predisposing factors, effect on visual function, and correlation with additional capsulotomy were evaluated. RESULTS: String of pearls was identified in 49 eyes (47.6%); 37 (75.5%) developed pearls within 1 year after Nd:YAG capsulotomy. The incidence was significantly higher in patients having intraocular lens implantation and continuous curvilinear capsulorhexis (CCC) than in those without (95.9 versus 61.1% and 97.9 versus 55.6%, respectively). No significant differences were found in patient age and sex, total Nd:YAG energy, and the presence of diabetes mellitus or high myopia. String of pearls caused visual disturbances in 17 eyes (34.7%). The rate of repeat capsulotomy was higher in patients with string of pearls than in those without (36.7 and 9.3%, respectively). CONCLUSIONS: String of pearls formation was a common and significant complication after Nd:YAG posterior capsulotomy. Intraocular lens implantation and CCC may promote its formation.

Adult↗

PubMed1997

Apoptotic cell death in rabbit lens after lens extraction.

PURPOSE: To determine whether apoptosis or necrosis of lens epithelial cells occurs after lens extraction. METHODS: Lens extraction was performed on 24 rabbit eyes. The authors then performed terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and transmission electron microscopy on the eyes 1 to 10 days after surgery. RESULTS: The postoperative lens was demarcated into three regions by the adhesion between the incised edge of the anterior capsule and the posterior capsule: the adhesive region, the intracapsular region, and the central portion of the posterior capsule. By day 2, TUNEL-positive cells with morphologic characteristics of necrosis were detected in the intracapsular region. Beginning on day 5, TUNEL-positive cells with morphologic characteristics of apoptosis and necrosis were detected in the adhesive region. Apoptotic cell death in this region was detected among the myofibroblast-like cells. Lens epithelial cells that had extended onto the central portion of the posterior capsule began to diminish on day 8 or 9, some of them morphologically demonstrating necrotic changes. CONCLUSIONS: Apoptosis of lens epithelial cells occurs in the process of wound healing and reepithelialization after lens extraction, leading to secondary cataract. If the induction of apoptosis is better understood, protocols might be developed that could prevent reepithelialization through apoptosis, thus delaying or preventing secondary cataracts.

Animals↗

PubMed1996

Lens epithelial cell proliferation onto the intraocular lens optic in vitro.

PURPOSE: To determine how lens epithelial cells (LECs) proliferate onto an intraocular lens (IOL) after extracapsular cataract surgery. SETTING: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. METHODS: We cultured the capsular bags retaining LECs of eight human eye-bank eyes and six rabbit eyes that had had extracapsular lens extraction with in-the-bag implantation of a poly(methyl methacrylate) (PMMA) IOL and a PMMA ring. Cell proliferation onto the IOL optic was monitored by a time-lapse video system. RESULTS: Cells proliferated onto the IOL optic via the anterior capsulotomy margin, the inner surface of the anterior capsule, and the posterior capsule. They formed cell sheets similar to the membranes observed in clinical cases. CONCLUSIONS: Since the cells proliferated from the anterior capsule as well as from the posterior capsule onto the IOL optic, the membranes observed clinically on the IOL optic may be LEC sheets.

Adult↗

PubMed1996

Presence of alpha smooth muscle actin in lens epithelial cells of aphakic rabbit eyes.

AIMS: To determine whether alpha smooth muscle actin (alpha-SMA), a marker for myofibroblastic cells, is present in lens epithelial cells (LECs) in rabbit aphakic eyes. METHODS: Phacoemulsification was performed in rabbit eyes, which were enucleated after surgery. Immunohistochemical methods were used to detect alpha-SMA in LECs. RESULTS: Five days after surgery, the presence of alpha-SMA positive LECs was observed mainly around the adhesive portion of the anterior capsule margin and the posterior capsule. The posterior capsule was wrinkled at the adhesive portion. The alpha-SMA positive LECs were flattened with spindle-shaped cross sections. Seven days after surgery, the alpha-SMA positive LECs covered most of the central posterior capsule. They disappeared 10 days after surgery. On the other hand, the cuboidal LECs in the capsular bag were negative for alpha-SMA. CONCLUSION: The flattened LECs with spindle-shaped cross sections observed 5 days after cataract surgery contained alpha-SMA. Such LECs were distinguished biochemically from the cuboidal LECs, which lacked alpha-SMA.

Actins↗

PubMed1996

[An autopsy case of rheumatoid arthritis associated with proliferative endarteritis died of sudden severe melaena].

A 68-year-old male with a 2-year history of rheumatoid arthritis was hospitalized due to severe polyarthritis. Since level of rheumatoid factor was high, and subcutaneous nodules and cutaneous ulcers were present, the case was diagnosed as malignant rheumatoid arthritis (rheumatoid vasculitis). On 10th day after admission, severe dyspnea developed due to acute heart failure, followed by severe melaena. The patient did not respond to various treatments including steroid pulse therapy, and died 3 days later. Autopsy revealed widespread hemorrhagic infarction that was extended from the colon to the rectum. Proliferative endarteritis was recognized in mesenteric vessels, however neither necrosis nor inflammatory changes were observed. The melaena was caused by the interstinal infarction. The intestinal infarction was thought to be responsible for the circulatory disturbances due to heart failure in obstructive vessel lesion of mesenteric vessels.

Aged↗

PubMed1996

TGF-beta 2 increases alpha-smooth muscle actin expression in bovine retinal pigment epithelial cells.

PURPOSE: To examine whether transforming growth factor-beta 2 (TGF-beta 2) induces the expression of alpha-smooth muscle actin (SMA), a biochemical marker of myofibroblasts, in cultured bovine retinal pigment epithelial (RPE) cells. METHODS: Bovine RPE cells were cultured in F-12 nutrient mixture supplemented with 5% fetal bovine serum (FBS), with or without TGF-beta 2 (0.01-10 ng/ml) for 6 days. During this culture period, cells did not reach a confluence. Alpha-SMA was detected immunocytochemically with a mouse monoclonal antibody, and the ratio of the number of alpha-SMA positive cells to the total number of cells was calculated. RESULTS: About 10% of the cells in control cultures with only FBS were positive for alpha-SMA. TGF-beta 2 increased the ratio of positive cells dose-dependently (p < 0.0001), while a neutralizing antibody against TGF-beta 2 blocked this effect. CONCLUSIONS: TGF-beta 2 induced expression of alpha-SMA in bovine RPE cells.

Actins↗

PubMed1995

Effect of intraocular lens design on posterior capsule opacification after continuous curvilinear capsulorhexis.

We compared the effect of biconvex and convex-plano (posterior plano) intraocular lenses on posterior capsule opacification (PCO) following continuous curvilinear capsulorhexis (CCC) in 212 eyes. During the three years following surgery, the cumulative frequency of neodymium:YAG laser posterior capsulotomy, calculated with the Kaplan-Meier method, was significantly higher in patients in the biconvex group (32.5% by the third year) than in those in the convex-plano group (5.9% by the third year) (P < .05, Wilcoxon's test; P < .01, Cox-Mantel's test). Measured with the tracing method, the area within a 5 mm diameter central circle that developed Elschnig pearls was 2.93 +/- 4.91 mm2 in the biconvex group and 1.66 +/- 2.37 mm2 in the convex-plano group. In the study, PCO was less severe in the convex-plano group than in the biconvex group following CCC. These results are contrary to those reported previously in patients with can-opener capsulotomy.

Adult↗

PubMed1995

[An autopsy case of dermatomyositis with rapidly progressive interstitial pneumonia].

An autopsy case of dermatomyositis with rapidly progressive interstitial pneumonia is reported. a 48-year-old woman was admitted because of facial edematous erythema and muscular weakness. A diagnosis of dermatomyositis was made because of typical erythema and myogenic pattern of EMG, although serum creatine kinase was within normal range. The chest X-ray film showed that interstitial pneumonia was complicated. She was treated with prednisolone of 60 mg/day. Although erythema and althralgia was improved remarkably, interstitial pneumonia was progressed unfavorably. Therefore pulse therapy with methylprednisolone was administered twice, but failed to respond. After that interstitial pneumonia was progressed rapidly, she was died of respiratory failure. The autopsy findings detected that a degeneration and necrosis of striated muscular fibers in whole body, that a mixed findings of usual interstitial pneumonia and diffuse alveolar damage in the lung. Vasculitis and fiblinous pleuritis was also found in the lung. Malignancy was not detected.

Dermatomyositis↗

PubMed1995

Growth factors influence contractility and alpha-smooth muscle actin expression in bovine lens epithelial cells.

PURPOSE: To determine whether basic fibroblast growth factor (bFGF) and transforming growth factor-beta 2 (TGF-beta 2) influence the contractile activity and the expression of alpha-smooth muscle actin (alpha-SMA) in bovine lens epithelial cells (LECs). To examine whether modulation of contractile activity by these growth factors depends on changes of alpha-SMA expression. METHODS: Bovine LECs were cultured in collagen gel in MED 5 medium (F-12 nutrient mixture supplemented with 5% fetal bovine serum) with or without bFGF (1 to 100 ng/ml) or TGF-beta 2 (0.01 to 10 ng/ml). To evaluate collagen gel contraction, the longest and shortest diameters of the gels were measured daily for 7 days, and the area was determined. Detection of alpha-SMA in the gels was performed immunohistochemically using a mouse monoclonal antibody against alpha-SMA. The percentage of alpha-SMA-positive cells to the total number of cells was determined. RESULTS: Control gels cultured with MED 5 medium alone contracted to 15.8% +/- 3.4% of their original area after 7 days. TGF-beta 2 significantly increased this contraction in a dose-dependent manner, whereas bFGF significantly decreased it. Approximately 30% of cells in the control gels were alpha-SMA positive. TGF-beta 2 significantly increased the alpha-SMA positivity dose dependently, whereas bFGF significantly decreased it. The percent positivity for alpha-SMA and the gel area showed a significant negative correlation. CONCLUSIONS: TGF-beta 2 increased collagen gel contraction and alpha-SMA expression in bovine LECs, whereas bFGF decreased these parameters. Because collagen gel contraction was correlated with alpha-SMA expression, the modulation of LEC contractile activity by growth factors may be related to an effect on alpha-SMA.

Actins↗

PubMed1994

Substitution of cysteine for glycine-946 in the alpha 1(I) chain of type I procollagen causes lethal osteogenesis imperfecta.

Procollagen synthesized by skin fibroblasts from a patient with a lethal variant of osteogenesis imperfecta has been characterized. After pepsin digestion of the type I procollagen, a portion of the alpha 1(I) chains was recovered as a disulfide-bonded dimer. Cyanogen bromide peptide mapping suggested that a new cysteine residue was present in the alpha 1(I)CB6 fragment. Sequencing of cloned cDNAs prepared using mRNA from the proband's fibroblasts demonstrated that some of the clones contained a single base mutation that converted the glycine codon in amino acid position 946 of the alpha 1(I) chain to a cysteine codon. The thermal stability of the molecules was markedly lower than that in the case of the normal control.

Base Sequence↗

PubMed1994

Inhibitory effect of TGF-beta 2 in human aqueous humor on bovine lens epithelial cell proliferation.

PURPOSE: To determine whether transforming growth factor-beta 2 (TGF-beta 2) in human aqueous humor inhibits the proliferation of lens epithelial cells. METHODS: Bovine lens epithelial cells (BLECs) obtained from the central zone of the anterior capsule were cultured in complete medium (F-12 nutrient mixture supplemented with 5% fetal bovine serum). Human aqueous humor was obtained from 11 patients during cataract surgery. Medium was removed and replaced with medium containing various concentrations of porcine platelet-derived TGF-beta 2 or 10% human aqueous humor, with or without anti-TGF-beta 2 neutralizing antibody. The number of cells was counted at 96 hours. RESULTS: Porcine platelet-derived TGF-beta 2 inhibited BLEC proliferation in a dose-dependent manner. Anti-TGF-beta 2 antibody blocked the inhibitory effect of TGF-beta 2 on BLEC proliferation. The 10% human aqueous humor stimulated the proliferation of BLECs. Addition of anti-TGF-beta 2 antibody to the 10% human aqueous humor significantly enhanced this stimulatory effect on BLEC proliferation. CONCLUSIONS: TGF-beta 2 in human aqueous humor inhibits the proliferation of lens epithelial cells in vitro.

Aged↗

PubMed1991

Apolipoprotein E deficiency with a depressed mRNA of normal size.

We studied a 39-year-old man who had palmar xanthomas complicated with marked hyperlipidemia. His serum cholesterol and triglyceride were 2000 and 6300 mg/dl, respectively. Serum apolipoprotein E (apo E) was undetectable in the patient by the methods of single radial immunodiffusion, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and radioimmunoassay. Serum apo E concentrations of his father and sister were low. This evidence is consistent with a diagnosis of familial apo E deficiency. We studied the synthesis of apo E in cultures of peripheral blood monocyte macrophages (M-M cultures) obtained from the patient, and detected no secretion of apo E in the culture medium and no newly synthesized apo E in the cell lysate. There were only trace amounts of apo E mRNA of the M-M cultures and the size of the mRNA appeared the same as normal apo E mRNA, indicating a different mutation of the gene from that of the case reported by Zannis et al. (J. Biol. Chem., 260 (1985) 12891).

Adult↗

PubMedDate not supplied

Clinical evaluation of a five-zone refractive multifocal intraocular lens.

PURPOSE: To evaluate the clinical performance of a five-zone refractive multifocal intraocular lens (AMO, model MPC-25NB, Array). METHODS: We performed a retrospective clinical trial of 31 cataract patients (mean age 64.3 years). The parameters studied were intraoperative and postoperative complications, distance and near visual acuity, spectacle use, decreased number of corneal endothelial cells, contrast sensitivity, percentage of glare disability, near binocular vision, and depth of focus. RESULTS: Intraoperatively, iris damage occurred in two eyes (4.2%), vitreous loss in one eye (2.1%), and consecutive rupture of Zinn's zonule and vitreous in one eye (2.1%). Postoperatively, posterior capsule opacification was observed in two eyes (4.2%), temporary intraocular pressure increase in one eye (2.1%), and cystoid macular edema in one eye (2.1%). Uncorrected distance visual acuity of 20/40 or better was achieved by 34 of 37 eyes (91.9%) with less than 1.5 diopters of preoperative keratometric astigmatism; best corrected distance acuity of 20/20 or better was achieved by 41 of 45 eyes (91.1%). Near visual acuity with distance correction of 20/40 or better was achieved by 29 of 43 eyes (67.4%). These data were compared retrospectively with data from control patients who received monofocal lenses, and no significant differences in the decreased number of corneal endothelial cells were found. Mean contrast sensitivities were within normal range for all spatial frequencies. Percentage of glare disability and near binocular vision were within normal limits. CONCLUSIONS: Eyes implanted with the five-zone refractive multifocal lens showed better near visual acuity than control eyes and compared favorably in other aspects of visual function, indicating that these lenses are effective and safe.

Adult↗

PubMedDate not supplied

Effect of rabbit aqueous humor obtained after cataract surgery on collagen gel contraction induced by bovine lens epithelial cells.

We evaluated the effect of specimens of pre- and postoperative aqueous humor on the contraction of collagen gels, and the effect of transforming growth factor-beta(2) (TGF-beta(2)) in postoperative aqueous humor. Rabbit aqueous humor was collected preoperatively and on postoperative day 7. Bovine lens epithelial cells (LECs) were cultured in collagen gel in F-12 nutrient mixture supplemented with 5% fetal bovine serum that contained 10% aqueous humor obtained under various conditions. Gel area was determined on day 4. Gels cultured with the medium that contained phosphate-buffered saline showed a statistically significant contraction after 4 days. Aqueous humor from aphakic or pseudophakic eyes significantly increased contraction, with both specimens having a similar effect. Approximately 60% of the contractile effect of the postoperative aqueous humor was neutralized by anti-TGF-beta(2) antibody. However, the promoting effect of the aqueous humor sampled postoperatively was less than that sampled preoperatively. Although the aqueous humor obtained postoperatively increased the contractility of the LECs, with the level of TGF-beta(2) apparently responsible for much of its effect, the effect was less than that observed in the aqueous humor obtained preoperatively.

Animals↗