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Biomedical subjects

R Manabe

Publications and source records attributed to R Manabe.

At least 37 records · Page 2Linked to original sources

Demonstration of herpes simplex virus DNA in idiopathic corneal endotheliopathy.

A 56-year-old man developed idiopathic corneal endotheliopathy. The lesion consisted of severe stromal edema at the lower half of the cornea along with a number of associated keratic precipitates and steadily progressed to the upper half of the cornea. By polymerase chain reaction, herpes simplex virus DNA was demonstrated in the aqueous humor of this patient. Corneal stromal edema was resolved in response to treatment with topically applied and systemic acyclovir. Herpes simplex virus DNA was repeatedly demonstrated in the aqueous humor when the endothelial lesion recurred later. This evidence strongly indicates that this unique endothelial disorder is of viral origin.

Antibodies, Viral↗

Long-term results of keratoepithelioplasty in Mooren's ulcer.

A consecutive series of 20 eyes with Mooren's ulcer was treated by a new surgical approach: keratoepithelioplasty alone or in combination with corneoscleral lamellar graft. Eighteen (90%) eyes showed complete remission promptly after surgery; the other two also healed with the administration of additional systemic and topical steroids. During the follow-up periods (mean, 3.1 years), minor recurrence was found in 5 (25%) eyes for the first 6 months, in none (0%) for the second 6 months, in 2 (12%) for the third 6 months, and none thereafter. All seven eyes with recurrence were cured by additional steroid treatment, alone or with conjunctival excision and/or keratoepithelioplasty. In the 18 (90%) eyes, the lenticules, constantly observed, remained silent on the scleras, which were free from conjunctival invasion. These results strongly support the authors' theory that keratoepithelioplasty using donor corneal lenticules can heal Mooren's ulcer via blockage of infiltrated conjunctival invasion.

Adult↗

[3H]mepyramine binding sites, histamine H1-receptors, in bovine retinal blood vessels.

The presence of histamine H1-receptors in the bovine retinal blood vessels was studied with a [3H]mepyramine binding assay. The membranes of purified vessels obtained from bovine retinas showed specific [3H]mepyramine binding sites with a dissociation constant (KD) of 2.78 +/- 0.32 nM. This was similar to values obtained from the retinal neuronal fractions. The binding capacity (Bmax) was 53.8 +/- 1.7 fmol/mg protein, which was about a half that of the retinal neuronal fractions (108.9 +/- 3.1 fmol/mg protein). Some H1-antagonists proved to be potent competitors for [3H]mepyramine binding sites in bovine retinal blood vessels. These results indicate that histamine H1-receptors exist in the retinal blood vessels which may be involved in the physiological and the pathological responses of blood circulation in retinas.

Animals↗

An analysis of the subpopulations in draining lymph node cells and MHC antigen induction in murine herpetic keratitis.

The protective role of T cell subsets in corneal herpes simplex virus type 1 (HSV-1) infection has been studied. However, the relative contribution of, and the role played by, each particular T cell subset still remain a controversial issue. We studied sequentially the appearance of major histocompatibility (MHC) and viral antigens in HSV-1 infected corneas of Balb/C mice and related them to induction of T cell subsets in local lymph nodes and corneal lesions. Immunohistochemical study has revealed a marked increase of expression of class II MHC antigen in the corneal stromal cells, while class I MHC antigen gradually increased in the corneal epithelium and stroma. Further immunohistochemical survey has revealed that L3T4 antigen bearing and Lyt 2 antigen bearing cells were induced to a similar extent with an equal rapidity in the local lymph nodes as well as in the corneal stroma. Transfer of these subpopulations to syngeneic nude mice showed that they played a role to prevent severe outcome of corneal herpetic infection. These results indicate that the corneal stroma is a major site of the host's immunological activities and both L3T4 and Lyt 2 bearing cells are equally important for the prevention of corneal herpetic infection.

Animals↗

[The effect of bunazosin hydrochloride on intraocular pressure and aqueous humor dynamics in human].

The effects of bunazosin hydrochloride, a new highly selective alpha 1 adrenergic antagonist, on the intraocular pressure (IOP) and aqueous humor dynamics in healthy human volunteers were studied. Unilateral topical administration of 0.1% bunazosin significantly lowered IOP from 1 to 10 hrs in bunazosin-treated eyes, and from 2 to 8 hrs in contralateral placebo-treated eyes, with its maximum reduction at approximately 3 hrs, when the IOP decreased 5.0 mmHg in treated eyes, and 3.5 mmHg in contralateral eyes from the baseline, respectively. Fluorophotometrically measured aqueous humor flow rates did not change significantly either in treated or contralateral eyes. Bunazosin caused significant reduction of systolic and diastolic blood pressure 5 hr after application. The difference in pupil diameter between treated and contralateral eyes was found to be statistically significant from 1 to 5 hrs. A small but significant increase in anterior chamber depth also was observed from 2 to 6 hrs. Pulse rate and refraction were not substantially altered. There was moderate conjunctival vessel dilation, however, no serious complications were encountered. The results suggest that bunazosin hydrochloride appears to have great clinical potential for ocular hypotensive therapy.

Adrenergic alpha-Antagonists↗

[The effect of recombinant epidermal growth factor in corneal angiogenesis].

Recent advances in genetic engineering techniques have enabled large-scale manufacture of human epidermal growth factor (hEGF), making possible the clinical use of this particular agent in treating a variety of corneal epithelial disorders. In view of future application to humans, it has to be determined whether hEGF could induce neovascularization in the cornea upon topical instillation, since the angiogenic effect of mouse EGF on the cornea in vivo has been reported. For this, a sheet of slow-release form polymer (EVA) containing hEGF was surgically implanted into the rabbit corneal stroma in search for subsequent corneal neovascularization. EVA sheets contained one of the following agents: (1) 250ng hEGF, (2) 500ng hEGF, (3) 250ng bFGF (positive control), (4) vehicle alone (negative control). On 5 and 14 days after implantation, the corneas were excised, sectioned, and stained with hematoxylin and eosin for histological evaluation. Slit lamp examination revealed that marked neovascularization developed in the corneas when EVA sheets containing bFGF were implanted. A number of polymorphonuclear leukocytes were accumulated around the implants. However, neovascularization did not occur in the corneas when EVA sheets containing either concentrations of hEGF or vehicle alone were implanted. Only a few polymorphonuclear leukocytes infiltrated. This result indicates that as much as 500ng hEGF does not induce corneal neovascularization.

Animals↗

Histamine and its synthesis in mammalian retinas.

Histamine (HA) content and histidine decarboxylase (HDC) activity were studied in the sensory retinas of the rat, guinea-pig, rabbit, dog, monkey, bovine and pig. Using a highly sensitive and specific method developed for the determination of histamine using high-performance liquid chromatography, HA was detected in the retinas of all species examined. HA content ranged from 11 (bovine) to 540 pmole/g wet tissue (dog), and HDC activity ranged from 2 (rabbit) to 150 (dog) fmol HA synthesized/min/mg protein. With the exception of the dogs, the retinal values were one order lower than those in the brain in all species examined. The canine retinas had the high HA and HDC values among the species examined, and were approximately equal to those in the brain. However, the ratios of HDC activity to HA content ranged from 0.04/min to 0.51/min. These values resembled those in the brain and were much higher than those in mast cells. This suggests that histamine in the retinas exists mainly in the neurons even though the actual amounts are small and may be involved in the physiological and the pathological responses in mammalian retinas.

Animals↗

Localization of two calcium binding proteins, calbindin (28 kD) and parvalbumin (12 kD), in the vertebrate retina.

We used immunocytochemistry to locate two calcium binding proteins, calbindin (CaB) and parvalbumin (PV), in the retina of goldfish, frog, chick, rat, guinea pig, dog, and man. The location of CaB depended on the type of dominant photoreceptor cells in birds and mammals. In cone-dominant retinas such as those of the chick, CaB-like immunoreactivity was found in the cones, cone bipolars, and ganglion cells. Amacrine cells 5-12 microns across were also labeled. In rod-dominant retinas, such as those of the rat, guinea pig, and dog, horizontal cells, small amacrine cells (about 6 microns across), and cells in the ganglion cell layer were labeled. In the human retina, which has both cones and rods in abundance, cones, cone bipolars, ganglion cells, horizontal cells, and small and large amacrine cells were labeled. In the frog and goldfish, the level of CaB-like immunoreactivity was low. In the frog, a few cones, amacrine cells, and cells in the ganglion cell layer were labeled. No immunoreactive structures were seen in the goldfish retina. PV-like immunoreactivity was found in chicks, rats, and dogs. No such immunoreactive structures were seen in the other species. In the chick, only amacrine cells were labeled. In the rat, amacrine cells and several displaced amacrine cells were labeled. In the dog, in addition to amacrine cells and displaced amacrine cells, horizontal cells were strongly labeled. Thus, PV-like immunoreactivity was found in those elements relating to the modulation of the main pathway of the visual transmission system.

Animals↗

Herpes simplex virus glycoprotein D. Protective immunity against murine herpetic keratitis.

%$%%protective effect of glycoprotein D (gD) immunization against murine herpetic keratitis was investigated. gD was purified by affinity chromatography using anti-gD monoclonal antibodies. Prior immunization with gD was shown to be effective in protecting mice from both the development of stromal keratitis and the spread of the virus to the central nervous system. The level of serum antibodies for virus neutralization, as well as for complement-dependent cytolysis (CDC), was significantly elevated in gD-immunized animals. Cellular immunity, however, was not detected. These results indicate that two antibody-mediated defense mechanisms--virus neutralization and CDC--were responsible for the protective effect observed in our study.

Animals↗

Glutathione conjugation of methazolamide and subsequent reactions in the ciliary body in vitro.

Conjugation reaction of methazolamide with glutathione and its subsequent reactions were studied in vitro. Glutathione, cysteinylglycine, and cysteine conjugates of methazolamide were chemically synthesized. All of the three compounds showed absorbance below 330 nm, with maximal absorbance at approximately 300 nm. At the wavelengths below 220 nm, absorbance was proportional to the number of the amino acids each compound had. Amino acid analysis of the glutathione conjugate showed that the conjugation reaction involved the cysteine residue of glutathione. In order to identify the chemical structure of the reaction product, cysteine conjugate was subjected to infrared, proton nuclear magnetic resonance, and mass spectral analyses. These studies indicated that the cysteine conjugate was S-(5-acetylimino-4-methyl-delta 2-1,3,4-thiadiazolinyl)cysteine. The reaction with glutathione was not catalyzed by glutathione S-transferases, but proceeded in the absence of the enzyme. The glutathione conjugate was degraded by bovine ciliary body homogenate to the cysteinylglycine conjugate and then to the cysteine conjugate.

Animals↗

Monoclonal antibodies against the mercaptoethanol-sensitive structure of a cell-cell adhesion protein of Polysphondylium pallidum.

Monoclonal antibodies were prepared against a putative cell-cell adhesion glycoprotein, with an apparent molecular mass of 64,000 (gp64), of the cellular slime mold, Polysphondylium pallidum. Five monoclonal antibodies obtained by means of an enzyme-linked immunoadsorbent assay did not bind to the antigens which were subjected to gel electrophoresis and blotting method in the presence of a reducing agent, but they did bind specifically to the antigens prepared in unreducing conditions of samples and then processed by the same blotting method. To solubilize gp64 in a sodium dodecyl sulfate (SDS)-sample buffer without mercaptoethanol (heated) or SDS-sample buffer with 2-mercaptoethanol (nonheated) was critical for the antibody binding onto gp64 on a membrane. Hence the antibodies seem to bind to a surface portion(s) of the localized protein structure folded up by disulfide cross-linkages. One of the antibodies obtained blocked cell-cell adhesion by about 20%.

Animals↗

[In vitro sensitivity to antiviral agents of herpes simplex viruses isolated from patients with herpetic keratitis].

Thirty-five clinical isolates of herpes simplex virus type 1 (HSV-1) from 34 patients (35 eyes) with herpetic keratitis were examined in vitro for 5-iodo-2'-deoxyuridine (IDU) and acyclovir (ACV) sensitivity. In addition, the effect of clinical treatment with these two drugs in herpetic keratitis was also investigated. The viral effective dose50 (ED50) was defined as the concentration that inhibited the plaque count by 50% compared to the count of the no drug controls. The viral ED50 of IDU ranged from 0.073 to 0.77 micrograms/ml (0.33 +/- 0.16; Mean +/- SD) and that of ACV from 0.0032 to 0.33 micrograms/ml (0.13 +/- 0.11). No virus with markedly diminished sensitivity to IDU and ACV was found. These results suggest that all HSV-1 strains isolated from patients have good sensitivity in vitro to antiviral agents.

Acyclovir↗

[Herpes simplex virus latency in the cornea].

We tried to identify herpes simplex virus type 1 (HSV-1) latency in the cornea obtained at the time of penetrating keratoplasty from patients with herpetic stromal keratitis in the non-active (subsided) stage. The subject consisted of 8 patients (3 males and 5 females; average age 42.3 years) who were diagnosed as having herpetic stromal keratitis and underwent penetrating keratoplasty during a period without active lesions (subsided stage) between August, 1984 and July, 1988. No infective virus was detected in the centrifugation supernatant following each corneal homogenization. Latent virus was detected from the culture supernatant of sections of the corneas in 4 of the 8 patients. Although the ganglion trigger theory of Hill et al. has been conventionally supported as the mechanism(s) of herpetic keratitis recurrence, our results suggest that HSV-1 proliferation from latency in the cornea (peripheral tissue) might stimulate the ganglion (ganglion and skin trigger theory). The present study is the first to demonstrate HSV-1 latency in the cornea.

Adult↗

The mechanism of accelerated corneal epithelial healing by human epidermal growth factor.

The effect of biosynthetic human epidermal growth factor (hEGF) was investigated on a 10-mm diameter corneal epithelial defect model in rabbits. Topical application of over 10 micrograms/ml of hEGF five times a day significantly enhanced the epithelial healing rate, in a dose-dependent manner. The maximum healing rate was observed in eyes treated with 20 micrograms/ml of hEGF (1.59 +/- 0.26 mm2/h), whereas application of less than 5 micrograms/ml of hEGF did not increase the rate of epithelial regeneration compared statistically with control vehicles (1.03 +/- 0.24 mm2/h). S-phase analysis indicated that hEGF treatment induced a high rate of epithelial replication, particularly near the limbal region, during 12 to approximately 24 hours after wounding, followed by massive cell replication from 1 mm behind the leading edge through the limbus during 24-48 hours. The change in number and distribution of S-phase cells thereafter did not essentially differ between hEGF-treated and control groups. In concordance with the S-phase analysis, there was a statistically significant increase in the DNA content in regenerating epithelium at 48 and 72 hours in the hEGF-treated group. These findings indicate that hEGF-induced acceleration of large corneal epithelial wound healing is associated with about twofold cell replication in the regenerating epithelium during 24 to approximately 48 hours after wounding. It is concluded that cell proliferation induced by hEGF, particularly that in limbal and peripheral corneal epithelial cells, may play an important role in accelerating epithelial healing.

Administration, Topical↗

Coexistence of enkephalin and somatostatin in the chicken retina.

A double immunostaining method was used in the present study to demonstrate that enkephalin (ENK) and somatostatin (SOM) coexist within single amacrine cells of the chicken retina. The ratio of double-labeled cells to either ENK- or SOM-bearing cells was more than 90%, indicating that retinal ENK and SOM are most likely to be found together in the same amacrine cell. This rate of colocalization is the highest yet observed among any neurotransmitters and modulators that coexist.

Animals↗

The effect of hard contact lens wear on the keratoconic corneal endothelium after penetrating keratoplasty.

Using wide-field specular microscopy, we evaluated the morphologic features of the corneal endothelium in 14 eyes of 14 patients with keratoconus who had worn a polymethylmethacrylate hard contact lens for at least four years (mean, 71 months) after penetrating keratoplasty. Comparisons were made with 14 non-lens-wearing eyes of 14 patients with keratoconus matched for age, length of postoperative period, and other variables. Examination of the endothelium of the contact lens wearers showed a significantly higher coefficient of variation in cell size (polymegethism) and a marked decrease in the percentage of hexagonal cells (pleomorphism), with a significant decrease in cell density (P less than .05). The cause of these morphologic abnormalities remains unclear but may be related to lens-induced hypoxic stress to the corneal endothelium causing ongoing cell loss.

Cell Count↗

A case of neurofibroma located in the retroperitoneum involving the uncinate process of the pancreas.

A case of solitary neurofibroma in the retroperitoneum involving the uncinate process of the pancreas, which has been reported in only one case in Japan and less than 20 cases in the world literature, is described. A 57-year-old male complained of back pain and microhematuria. Plain and enhanced abdominal computed tomography (CT) indicated an 8 x 6 cm hypovascular tumor located in the uncinate process. We initially assumed it to be a cancer of the pancreas. His physical examination and blood chemistry result were normal. Various diagnostic imaging methods however, disclosed a rare type of tumor. The tumor was resected by pancreaticoduodenectomy and histological examination revealed it to be neurofibroma.

Humans↗