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Biomedical subjects

Y Satake

Publications and source records attributed to Y Satake.

At least 19 recordsLinked to original sources
PubMed2000

Characterization of rat OX40 ligand by monoclonal antibody.

OX40 (CD134) is a member of the tumor necrosis factor (TNF) receptor superfamily first identified as a rat T cell activation marker. We previously identified the rat ligand for OX40 (OX40L) by molecular cloning. In the present study, we newly generated an anti-rat OX40L mAb (ATM-2) that can inhibit the binding of OX40 to rat OX40L and thus efficiently inhibits the T cell costimulatory activity of rat OX40L. Flow cytometric analyses using ATM-2 and an anti-rat OX40 mAb (MRC OX40) indicated that OX40 was inducible on splenic CD4(+) T cells by stimulation with immobilized anti-CD3 mAb, while OX40L was not expressed on resting or activated T cells. OX40L was expressed on splenic B cells after stimulation with lipopolysaccharide (LPS), but not on peritoneal macrophages. Interestingly, splenic dendritic cells (DC) expressed OX40L constitutively, which was further upregulated by LPS stimulation. The potent costimulatory activities of splenic DC for anti-CD3-stimulated rat CD4(+) T cell proliferation and cytokine (IL-2, IFN-gamma, IL-10, and IL-13) production were substantially inhibited by ATM-2. These results indicated that OX40L is expressed on professional antigen-presenting cells (APC), and may be involved in humoral immune responses via T-B interaction and in cellular immune responses via T-DC interaction in the rat system.

Animals↗
PubMed1999

Treatment of severe ocular-surface disorders with corneal epithelial stem-cell transplantation.

BACKGROUND: Conditions that destroy the limbal area of the peripheral cornea, such as the Stevens-Johnson syndrome, ocular pemphigoid, and chemical and thermal injuries, can deplete stem cells of the corneal epithelium. The result is scarring and opacification of the normally clear cornea. Standard corneal transplantation cannot treat this form of functional blindness. METHODS: We performed and evaluated 70 transplantations of corneal epithelial stem cells from cadaveric eyes into 43 eyes of 39 patients with severe ocular-surface disorders and limbal dysfunction. Medical treatment had failed in all patients. The patients had a mean preoperative visual acuity of 0.004 (only being able to count the number of fingers presented by the examiner) in the affected eyes, which satisfies the criteria for legal blindness in most countries. In 28 eyes, we also performed standard corneal transplantation. Stem-cell transplantations were performed as many as four times on 1 eye if the initial results were not satisfactory; 19 eyes had multiple transplantations. Patients were followed for at least one year after transplantation. RESULTS: A mean of 1163 days after stem-cell transplantation, 22 of the 43 eyes (51 percent) had corneal epithelialization; of the 22 eyes, 7 eyes had corneal stromal edema and 15 eyes had clear corneas. Mean visual acuity improved from 0.004 to 0.02 (vision sufficient to distinguish the largest symbol on the visual-acuity chart from a distance of 1 m) (P<0.001). The 15 eyes in which the cornea remained clear had a final mean visual acuity of 0.11 (the ability to distinguish the largest symbol from a distance of 5 m). Complications of the first transplantation included persistent defects in the corneal epithelium in 26 eyes, ocular hypertension in 16 eyes, and rejection of the corneal graft in 13 of 28 eyes. The epithelial defects eventually healed in all but two of the eyes. CONCLUSIONS: Transplantation of corneal epithelial stem cells can restore useful vision in some patients with severe ocular-surface disorders.

Adult↗
PubMed1999

[Long-term prognosis of ulcerative colitis].

Despite its intermittent course of activity and remission, the good response to salazopyridine and steroids makes the long-term prognosis of ulcerative colitis favorable. The number of non-active type ulcerative colitis is increasing and consequently, the rate of active disease and relapse is decreasing every year. More than 90% of the patients even with disease of 10 or more years are able to work almost with no limits for the daily living. The colectomy rate in Japan is 4.1% after one year of the onset of the disease and 6.8% after 2 years. Thereafter approximately 1% of the patients undergo surgery yearly. The most common reasons of surgery are complications such as massive bleeding, perforation or toxic megacolon. Other indications are chronic continuous disease and cases with frequent relapses. Considering the extension of the disease, about one-third of the total colitis type and 10% of the left-sided type undergo surgery. The risk of colonic cancer is higher in patients with total colitis type and when has had the disease for more than 10 years. Most of the them are flat type poor-differentiated adenocarcinomas. Therefore patients with total colitis type for more than 10 years should undergo colonoscopic surveillance.

Adenocarcinoma↗
PubMed1998

A new surgical technique for deep lamellar keratoplasty with single running suture adjustment.

PURPOSE: To improve the technique of deep lamellar keratoplasty. METHODS: For the recipient eye, a divide-and-conquer technique was applied to deep lamellar keratoplasty. After trephinization, the recipient cornea within the trephine was divided into four quadrants to facilitate lamellar dissection at approximately 70% depth. This procedure of division was continued until the Descemet membrane was exposed in the central area. The corneal graft was placed with an adjusted single running suture. Seventeen eyes were treated with this technique. RESULTS: In 17 eyes of 15 patients, the mean visual acuity 6 months or more after deep lamellar keratoplasty was 20/52 with eyeglass correction and 20/80 without eyeglass correction. At 6 months or more after deep lamellar keratoplasty, the mean +/- SD keratometric astigmatism in 17 eyes was 3.2 +/- 2.3 diopters. CONCLUSION: This technique facilitates deep lamellar keratoplasty and prevents high or excessive astigmatism after surgery.

Astigmatism↗
PubMed1996

Common T cell receptor clonotype in lacrimal glands and labial salivary glands from patients with Sjögren's syndrome.

Sjogren's syndrome (SS) is an autoimmune disease characterized by lymphocytic infiltration into lacrimal and salivary glands leading to symptomatic dry eyes and mouth. Immunohistological studies have clarified that the majority of infiltrating lymphocytes around the lacrimal glands and labial salivary glands are CD4 positive alphabeta T cells. To analyze the pathogenesis of T cells infiltrating into lacrimal and labial salivary glands, we examined T cell clonotype of these cells in both glands from four SS patients using PCR-single-strand conformation polymorphism (SSCP) and a sequencing method. SSCP analysis showed that some infiltrating T cells in both glands expand clonally, suggesting that the cells proliferate by antigen-driven stimulation. Intriguingly, six to sixteen identical T cell receptor (TCR) Vbeta genes were commonly found in lacrimal glands and labial salivary glands from individual patients. This indicates that some T cells infiltrating into both glands recognize the shared epitopes on autoantigens. Moreover, highly conserved amino acid sequence motifs were found in the TCR CDR3 region bearing the same TCR Vbeta family gene from four SS patients, supporting the notion that the shared epitopes on antigens are limited. In conclusion, these findings suggest that some autoreactive T cells infiltrating into the lips and eyes recognized restricted epitopes of a common autoantigen in patients with SS.

Amino Acid Sequence↗
PubMed1996

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↗
PubMed1996

[Early colorectal cancer].

Early colorectal cancer is situated at the field with a rich stock of topics in Japan. For this reason, there are increasing number of patients with colorectal cancer, many reports of depressed early cancer and rapid advances of molecular biology about colorectal neoplasm. Most of early colorectal cancers are discovered to be the protruded type by all accounts in spite that many cases of depressed type early cancer have been reported in many Japanese institutes. The final diagnosis of early colorectal cancer is usually made by histological examination after endoscopic resection, however invasive cancers with distinct endoscopic appearance of submucosal spread should be treated surgically from the beginning after diagnosis on biopsy specimens.

Colonoscopy↗
PubMed1995

A t(11;14)(p13;q11) specific for T-cell malignancies in acute megakaryoblastic leukemia.

A 2-year-old girl with a very rare form of acute megakaryoblastic leukemia (AMKL), having the 11p13;14q11 translocation specific for T-cell malignancies, is reported. She was diagnosed as having AMKL on the basis of her bone marrow, which contained 30% megakaryoblasts identified by characteristic morphology on May-Giemsa stain, positive for platelet peroxidase activity and for the surface marker of platelet glycoprotein IIb/IIIa, CD41. Cytogenetic studies of marrow cells revealed 47,XX,i(7q), +der(11)t(11;14)(p13;q11), -14, +21. She achieved hematologic remission after two courses of chemotherapy including behenoyl cytarabine, acracinorubicin, 6 mercaptopurine, and prednisolone, but soon relapsed and died 11 months after admission. This case suggests that adequate diagnostic assessments of morphology, surface markers, and cytogenetics are necessary for proper diagnosis in leukemia and lymphoma, and that an important, though as-yet unidentified, gene in megakaryopoiesis may reside in the 14q11 chromosomal region.

Chromosomes, Human, Pair 11↗
PubMed1994

Isolation of anti-Beijing-1 group-specific monoclonal antibody and antigenic analysis of Japanese encephalitis viruses in India.

Based on the reactivities of monoclonal antibodies, we previously reported that 25 Japanese encephalitis (JE) virus strains fell into five antigenic groups: Nakayama, Beijing-1, Kamiyama, 691004 and Muar. In the present study, we produced monoclonal antibodies against the Beijing-1 strain and obtained the Beijing-1 group-specific antibody, designated BEGMA 1. Furthermore, antigenic comparison of the seven JE virus strains isolated in India was performed by using BEGMA 1 and other group-specific antibodies. The results showed that six strains fell into the Kamiyama group to which the currently prevalent strains in Japan belong.

Antibodies, Monoclonal↗