Biomedical subjects

K Nango

Publications and source records attributed to K Nango.

5 recordsLinked to original sources

PubMed1993

[Diagnostic vitrectomy for chronic uveitis].

Uveitis is diagnosed by ophthalmologic and systemic examination, but it may be difficult to diagnose accurately in some chronic cases. We performed diagnostic and therapeutic vitrectomy for chronic uveitis in 6 eyes of 4 patients, and examined vitreous specimens with immunohistochemical staining. Visual acuity improved in all cases due to clearing up of the vitreous cells. One patient had sarcoidosis, one had B cell malignant lymphoma (ocular reticulum cell sarcoma), and two had reactive lymphoid hyperplasia. Vitrectomy for chronic uveitis is useful for diagnosis and improvement of vision, and we recommend immunohistological staining of vitreous specimens. Particularly, when intraocular lymphoma is suspected, vitrectomy must be performed early.

Aged↗

PubMed1992

[Histological changes in the retinal pigment epithelium and Bruch's membrane in senescence accelerated mouse].

Senescence associated changes of the retinal pigmented epithelium (RPE) and Bruch's membrane were investigated in senescence accelerated mouse (SAM), which is an aging model mouse, by light and electron microscopy. The most characteristic changes in RPE were swelling of basal infoldings, extension of intercellular space and accumulation of lipofuscin granules. In Bruch's membrane, discontinuation of elastic layer and abnormal increase of fine fibrils in the outer collagenous layer were observed. The aging changes in SAM were severer in the posterior retina than in the peripheral one. Moreover, these changes were seen younger age than in those of the normal BALB/c mouse.

Aging↗

PubMed1991

Ontogeny of thymic B cells in normal mice.

Ontogeny of thymic B cells and their surface characteristics were analyzed using monoclonal antibodies (mAbs) against B220 molecules (CD45, CD45R). A small number of B cells were detected in fetal thymus on Gestation Day 14 (approximately 3.5% of the low-density fraction). Similarly, the percentage of B cells in the low-density fraction was 3.2% on Gestation Day 18, and 3.5% on Day 1 after birth. These were the same level as that of adult mice. CD5+ B cells, which form the major population of thymic B cells, were also found in the fetal life (0.5% on Day 14 and 2.2% on Day 16 in the low-density cells). The percentage of CD5+ B cells in B cell-enriched fraction was about 65% on Day 1 after birth, which is the same level as that in adult mice. These results indicate that a small number of B cells or cells in the B-cell lineage are present in the fetal thymus and also suggest the importance of these thymic B cells in the negative selection of T cells during early developmental stages.

Animals↗

PubMed1991

Characterization of B cells in human thymus.

The surface characteristics of B cells present in the human thymus were investigated. Cytofluorometrical and immunohistological studies, using anti-human IgM or anti-B cell monoclonal antibodies (mAbs; anti-Leu 12Ab, anti-Leu 16Ab, or L26), revealed that a small number of B cells are present in the human thymus. The thymic B cells were detected only in a low-density cell population, whereas in a high-density cell fraction, only T cells were found. In 15 cases, all of which the thymi were histologically normal, the percentages of B cells in the low-density fraction were 0.28% to 50% (6.8% in average), and Leu 1+ (CD5+) B cells in the low-density fraction were 0.1% to 26% (3.5% in average); approximately 50% of the thymic B cells were Leu 1+ B cells. These results indicate that B cells, especially Leu 1 (CD5)+ B cells, are also present in the human thymus, as suggested from our previous reports on mice.

Adolescent↗

PubMed1990

Functional analyses of thymic CD5+ B cells. Responsiveness to major histocompatibility complex class II-restricted T blasts but not to lipopolysaccharide or anti-IgM plus interleukin 4.

The function of thymic B cells in several standard in vitro assays was investigated. Thymic B cells, 75% of which were CD5+, showed a poor responsiveness to the mitogens LPS or anti-mu plus IL-4. Both proliferation and antibody formation were much lower in thymic than splenic B cell cultures. However, CD5- B cells purified using a cell sorter responded well to B cell stimulants, whereas purified CD5+ thymic B cells did not, indicating that CD5+ thymic B cells were unresponsive to B cell growth factor or LPS. Thymic B cells could be activated polyclonally by direct interaction with alloreactive T blasts, as manifested by DNA synthesis and antibody formation. These findings indicate that CD5+ thymic B cells may not be stimulated via sIg and IL-4, but require instead direct interaction with T blasts.

Animals↗