Biomedical subjects

N Ohba

Publications and source records attributed to N Ohba.

At least 55 records · Page 3Linked to original sources

PubMed1997

[Glycohistochemical analysis of seborrheic keratosis in eyelids].

The glycoconjugates of seborrheic keratosis in the eyelids were examined by in situ hybridization histochemistry using cRNA probes for sialyltransferase (ST) and lectin histochemistry. We considered that the cells, which expressed both cytoplasmic distribution of ST-mRNA and binding of lectins specific for sialic acids to the cell surfaces, were actively producing sialoglycans. We also considered that the cells whose surfaces were stained with the lectins without cytoplasmic distribution of ST-mRNA have completed the synthesis of sialoglycans. These viewpoints suggest that the O-linked sialoglycan, whose turnover-rate is slow, may be distributed over the cells of the thickened spinocellular layer in the tumor of seborrheic keratosis and involved in its pathomechanism. It also appears that the turnover rate of the terminal sialic acids in the N-linked glycan in the spinocellular layer may be fast.

Aged↗

PubMed1997

[Lectin-histochemical study of early postnatal eyelid epithelium of the rat].

The glycoconjugates in neonate rat eyelids at postnatal day 0 or 1 were examined by lectin histochemistry. Maackia amurensis lectin II, which recognizes sialic acid alpha 2, 3 galactose beta 1, 3 N-acetylgalactosamine (Gal beta 1, 3 GalNAc) or sialic acid alpha 2, 3 galactose beta 1, 4 N-acetylglucosamine, bound to the cell membranes of the epithelial basal cells, suggesting that the glycoconjugates containing these sugar chains are present on their cell membranes. With respect to the binding of the Gal beta 1, 3 GalNAc-specific lectin, jacalin, whose binding is not inhibited by the terminal sialic acid, bound to the cell membranes of the epithelial basal cells, whereas peanut agglutinin, whose binding is inhibited by the terminal sialyl residue, did not bind to their cell membranes. These findings suggest that all the residues of Gal beta 1, 3 GalNAc in the glycoconjugates of their cell membranes are sialylated as the mature form.

Animals↗

PubMed1997

[Glycohistochemical analysis of apoptotic bodies in eyelid tumor].

To clarify the relation between the mechanism of apoptosis in tumor tissues and sialic acids on the termini of sugar chains of glycoconjugates, a case of squamous cell carcinoma was examined using immunohistochemistry and glycohistochemistry. Immunohistochemistry and in situ hybridization histochemistry suggested that sialylation by the sialyltransferase in dominant in tumor cells, whereas hydrolysis of sialic acids by the sialidase is dominant in apoptotic bodies. Lectin histochemistry revealed that sialic acid alpha 2, 3 galactose beta 1, 3 N-acetylgalactosamine (Gal beta 1, 3 GalNAc) is present on the surfaces of tumor cells, and Gal beta 1, 3 GalNAc is present on those of apoptotic bodies. The exposed Gal beta 1, 3 GalNAc owing to the decrease in sialic acids on the surfaces of apoptotic bodies may be recognized by the C-type lectin on the macrophage for phagocytosis.

Aged↗

PubMed1997

[Immunohistochemical distribution of keratin in malignant tumors of eyelids].

The type and distribution of keratins (K) in malignant tumors of eyelids were examined immunohistochemically to understand the pathomechanism of intercellular interactions. All of the tumor cells in the basal cell carcinoma were positive for K14, which is specific for basal cells, whereas all of them were negative for K10, which is specific for suprabasal layers in stratified squamous epithelia. These findings suggest that basal cell carcinoma may consist of uniform, basal cell-like tumor cells. On the other hand, the squamous cell carcinoma and sebaceous carcinoma, which were positive for either K14 or K10 to varying extent, may consist of various tumor cells with different types and degrees of differentiation. In these tumors, K14 was frequently detected throughout the border cells of the tumor mass. Apoptotic bodies were detected at the region where this continuous distribution of K14 was interrupted. These findings may help to clarify the pathomechanism of the interactions between the tumor cells and stromal cells.

Adenocarcinoma, Sebaceous↗

PubMed1997

[Immunohistochemical localization of cytosolic sialidase in the epithelium of rat cornea and conjunctiva].

The binding sites of the anti-cytosolic sialidase antibody and Maackia amurensis lectin II (MAL II: specific for sialic acid alpha 2, 3 galactose) in the epithelium of the rat cornea and conjunctiva were immunohistochemically and lectin-histochemically examined, respectively. Cytosolic sialidase was detected in the cytoplasm of the middle and basal epithelium of the cornea and conjunctiva, whereas MAL II bound to the apical region of their epithelium and the mucous of the goblet cells. The predominant action of the cytosolic sialidase, which is stronger than that of the sialyltransferase, may inhibit the terminal sialylation of the glycoconjugates at the middle and basal regions of the epithelium of the cornea and conjunctiva.

Animals↗

PubMed1997

[Effects of the age on the apoptotic and proliferative reactions in the constant light-exposed rat retina].

The effects of age (5-3 weeks old) on apoptotic changes in the rat photoreceptor cells induced by 3 days of constant light exposure were examined using TUNEL (TdT-mediated dUTP nick end labeling). The effects on the expression of the Ki67-antigen, which is a proliferative marker, in these photoreceptor cells were also examined by immunohistochemistry. The results suggested that the number of positive cells in the outer nuclear layer of the superior hemisphere is higher than in the inferior nuclear layer in both the TUNEL reaction and the distribution of the Ki67 antigen, and that the number of positive cells increases with age in general. The cells of monocytes/macrophages may locally proliferate in the retina to phagocytose the apoptotic bodies owing to the degeneration of photoreceptor cells. The present findings revealed that the rates of these reactions may generally increase with age.

Aging↗

PubMed1997

[Selective binding of fucose-recognizing lectin on the cone photoreceptor outer segments].

The distribution of fucose-containing glycoconjugates in the photoreceptor cell layer of rat and human retinas was examined by lectin histochemistry using Aleuria aurantia lectin (AAL), which recognizes L-fucose alpha 1, 6 residue. In the rate retina, AAL diffusely bound to the apical outer segments and to the basal inner segments, whereas it bound to the entire outer segments of other photoreceptors, which were considered to be cones due to their proportion. In the human retina, AAL bound diffusely to the basal inner segments and to the retinal pigment epithelia, but it bound selectively to the outer segments of the cones. The present findings revealed that the glycoconjugates, whose sugar chains contain L-fucose alpha 1, 6 residue on their termini, are present in the cone outer segments.

Animals↗

PubMed1997

[Immunohistochemical localization of MUC 1 and keratin 14 in the invasive regions of malignant eyelid tumors].

The distributional patterns of MUC 1 (the mucin whose cDNA was first cloned) and Keratin 14 (K14) in the invasive regions of malignant eyelid tumors were immunohistochemically examined by comparing with other histochemical markers. The MUC 1-positive tumor cells were detected in several serial, small, invasive tumor masses in the deep subepithelial region of the low differentiated carcinoma. They were also continuously detected in the border region between accumulated lymphocytes including T cells and tumor masses of the sebaceous carcinoma. On the other hand, K14-positive tumor cells were detected in the marginal regions of large tumor masses or those with smooth edges, some of which overlapped the distribution of MUC 1-positive cells in the tissues of undifferentiated carcinoma, squamous cell carcinoma, and sebaceous carcinoma. In general, MUC 1 may be expressed in the invasive tumor cells, whereas K14 may be expressed in the marginal cells of the stable, proliferating tumor masses.

Adenocarcinoma, Sebaceous↗

PubMed1996

A novel AvaI polymorphism within exon 5 of the rhodopsin gene.

We identified a novel AvaI polymorphism within 3' non-coding region within exon 5 of the human rhodopsin gene and determined the allele frequency in a Japanese population. The polymorphism was found to be due to A/G transversion at nucleotide 5510 of the gene.

Base Sequence↗

PubMed1996

Biochemical systematics of Japanese fireflies of the subfamily Luciolinae and their flash communication systems.

Japanese fireflies of the subfamily Luciolinae are biochemically analyzed using 13 allozymes, and the phylogenetic relationships obtained from this analysis are compared with their flash communication systems. As a result, the Japanese Luciolinae can be divided into three groups. Hotaria parvula and H. tsushimana together with Luciola yayeyamana and L. kuroiwae form the first group, and they use the same communication system. L. lateralis, Curtos okinawana, and C. costipennis make up the second group, and their communication systems are also the same. L. cruciata makes up the last one, and its communication system is different from the other fireflies of Luciolinae. Therefore, their taxonomical arrangement and communication systems are not congruent. However, the genetic similarity deduced by allozymic analysis of the members of the Japanese Luciolinae is highly consistent with their flash communication systems.

Animal Communication↗

PubMed1996

HTLV-I associated uveitis revisited: characteristic grey-white, granular deposits on retinal vessels.

AIMS: To elucidate whether there exists any clinical sign characteristic of HTLV-I associated uveitis. METHODS: Fifty five patients with HTLV-I associated uveitis were reviewed. These cases had serum antibodies to HTLV-I, and any other uveitis entities were carefully excluded by means of clinical and laboratory studies. RESULTS: Eight cases (14.5%) developed vascular lesions in the retina, characterised by grey-white, granular deposits scattered on the retinal veins and/or arteries in the posterior pole. The vascular changes did not accompany any haemorrhage, sheathing, or leakage of fluorescent dye on angiograms, and the retina was otherwise unremarkable. A single or clustered form of similar materials was also found to deposit on the vitreo-retinal interface of the foveolar area. These deposits resolved in a few weeks spontaneously or in response to corticosteroids together with anterior uveal inflammation. CONCLUSION: The vascular lesions described here suggest a characteristic sign for HTLV-I associated uveitis, and it may provide, if recognised, an additional clinical marker to establish diagnosis.

Adult↗

PubMed1996

[A predictive and prognostic study on two cases of transient hyperphosphatasemia of infancy].

We presented two cases with transient hyperphosphatasemia (TH) of infancy, whose serum alkaline phosphatase (EC 3.1.3.1, ALP) activity showed markedly increased and the atypical isoenzyme fractions were seen by electrophoresis. These isoenzymes migrated into normal bone ALP region (alpha 2-beta globulin fraction) and fast liver ALP region (fast alpha 2 globulin fraction). From various investigation such as, heat stability, inhibition test by amino acid, neuraminidase treatment and Triton X-100 treatment, former fraction seemed to derive from bone ALP and later fraction from liver ALP. From our study, increment of the activity of alpha 2-beta gl fraction was in advance one month before maximum ALP activity stage, and fast alpha 2 gl fraction followed increasing 3 weeks after that. On the other hand, decreasing of fast alpha 2 gl fraction showed a shorter delay than alpha 2-beta gl fraction. These results suggest that a differential exchange of sugar chain or an impaired clearance of the enzyme from circulation was possibly occurred. It seemed to be important to increase a study of such a predictive and prognostic change of ALP activity and isoenzyme fraction in TH cases.

Alkaline Phosphatase↗

PubMed1996

Assessment of mitochondrial gene in proliferative vitreoretinal tissues from patients with familial diabetes mellitus.

Fibrovascular tissues obtained at therapeutic vitrectomy from 22 patients with proliferative diabetic retinopathy were studied for a mutation of tRNALEU(UUR) at nucleotide position (np) 3243 of mitochondrial DNA (mtDNA). We found a mutation of mtDNA in the vitreous sample of one patient, a 44-year-old woman who had maternally inherited, familial, non-insulin-dependent diabetes mellitus of 25-year duration with recurrent vitreous hemorrhages due to proliferative retinopathy. Heteroduplex analysis also detected the mutant-type mtDNA in the vitreous sample of this patient. The abnormality was, however, not observed in the peripheral blood sample from either this patient orr her family members with diabetes mellitus. The other 21 patients were negative for the mutation in vitreous specimens as well as in peripheral blood. Although a firm conclusion cannot be drawn from a single case report, our observations suggest that this case was an example of tissue-specific expression of mtDNA mutation. Further studies of a larger number of patients with familial diabetes mellitus seem justified.

Adult↗

PubMed1996

HTLV-I associated retinochoroidal degeneration.

A review of 100 patients with HTLV-I associated myelopathy revealed 9 cases of retinochoroidal degeneration. The ocular disease was characterized by late onset, usually bilateral, progressive degenerative changes of the retina and choroid, which were preceded by, concurrent with, or followed by HTLV-I associated myelopathy. Ophthalmoscopic features were consistent with diffuse or localized retinochoroidal degeneration, the resultant functional disturbance being dependent on the extent of disease. It is noteworthy that the clinical picture in 3 cases was indistinguishable from primary retinitis pigmentosa. However, based on the prevalence of primary retinitis pigmentosa in the general population estimated from a questionnaire to ophthalmologists in the area, it was plausible that retinitis pigmentosa in HTLV-I associated myelopathy does not represent a coincidence of primary retinitis pigmentosa but a meaningful association with the neurological disease. Hence, we propose the existence of HTLV-I associated retinochoroidal degeneration (HARD) as a distinct disease. An additional study revealed that 21 (17.8%) of 118 patients with isolated, retinitis pigmentosa were seropositive for HTLV-I, the ratio being not significantly different from that in the general population. Therefore, the hypothesis that HTLV-I also contributes to an isolated form of retinochoroidal degenerative disease is not readily acceptable.

Adult↗

PubMed1996

[Age of onset of rhegmatogenous retinal detachment analyzed by Weibull distribution function].

We reviewed a series of 426 case or rhegmatogenous retinal detachment due to idiopathic retinal break and characterized the age at onset using a vital statistics model, Weibull distribution. When cases were divided into groups based on the type of retinal break, the cumulative frequency of each group could be described by the model. The equatorial atrophic hole group showed a frequency distribution which starts at about 7.5 years, culminates at about 20 years and terminates at about 40 years. The tractional tear group revealed two distinct distributions depending upon refractive errors; the non-high myopic subgroup showed a distribution which starts at 30 years and peaks at 60 years, and the high myopic subgroup had a distribution which starts at about 15 years and peaks at about 40 years. The macular hole group showed a distribution which starts in the second half of the third decade and peaks at about 60 years. The findings are consistent with the view that pathomechanisms having differing time courses are responsible for the age distribution at onset of rhegmatogenous retinal detachment caused by various types of retinal break.

Adolescent↗

PubMed1996

[A literature review of Norrie disease].

Norrie disease is a rare genetic disorder characterized by bilateral congenital blindness. The salient clinical feature early in life is a dense, white, vascularized mass behind each lens due to maldeveloped retina. Cataracts and corneal opacities are developed in young childhood, followed by bulbar atrophies. Histopathologic examination suggests primary vitreoretinal dysplasia because of developmental arrest of the retina in the middle embryonic stage. Occasional patients show psychomotor retardation or progressive hearing loss as part of a multisystem disorder. The disease is transmitted by an X-linked recessive form of inheritance, with sons of female carriers having a 50% risk for expressing the disease. In recent years, a candidate gene for Norrie disease has been isolated and characterized, which encompasses 27 kilobases and consists of three exons interspersed by two introns. Microdeletions and a variety of point mutations in the disease gene were identified in Norrie patients, although the genotype-phenotype correlation remains to be defined, and molecular diagnosis is now available for Norrie disease. The encoded protein has homology to a protein domain involving mucins and TGF beta, which may play an essential role in targeting of retinal/neural connections.

Blindness↗

PubMed1996

[Prevalence of endogenous uveitis in Kagoshima Prefecture, Southwest Japan].

To estimate the current trend in prevalence of endogenous uveitis and HTLV-I-associated uveitis (HAU) in a local area, we sent questionnaires to all ophthalmologic clinics in Kagoshima Prefecture, southern Japan, which has a population of 1.8 million, with reference to uveitis patients seen during May-July 1993 and May-June 1994. Answers to the questionnaires were obtained from about half of the ophthalmologists in each survey session. The proportion of uveitis cases was on the average 0.4% of outpatients, and the prevalence of uveitis was estimated to be 40.4 x 10(-5). The major uveitis entity consisted of toxoplasmosis (7.8%), Vogt-Koyanagi-Harada disease (5.0%), Behçet's disease (4.1%), sarcoidosis (3.4%), and 71.3% of unclassified cases. An additional study for the infection with HTLV-I revealed that the seropositivity for anti-HTLV-I antibodies was 11 (17.5%) of 63 patients with distinct uveitis entities and 38 (30.4%) of 125 patients with etiologically undefined uveitis, indicating no significant difference in HTLV-I infection between the two groups. The prevalence of HAU was estimated to be 8.8 x 10(-5).

HTLV-I Infections↗

PubMed1996

Immunohistochemical localization of cytosolic sialidase in photoreceptor cells.

The binding sites of the antibody to cytosolic sialidase on the rat and monkey photoreceptor cells were examined immunohistochemically using the avidin-biotinylated peroxidase method. In the rat photoreceptor cells, the antibody bound diffusely to the inner segment and the outer nuclear layers which are composed chiefly of rod cells. In the monkey photoreceptor cells, the antibody bound to the rod inner segments which were clearly distinct, morphologically, from the cone inner segments. The antibody also bound to the rod cell bodies in the outer nuclear layer. These binding patterns show that the antibody bound preferentially to rod photoreceptor cells. This observation is consistent with previous lectin histochemical findings that sialoglycans are preferentially present on the surfaces of rod photoreceptors, and in the rod-associated interphotoreceptor matrix. Sialidase in rod inner segments may function by balancing with sialyltransferase, also preferentially expressed in rod inner segments, to form sialyl residues on the termini of sugar chains in the rod-associated sialoglycoconjugates.

Animals↗