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Biomedical subjects

M Hishii

Publications and source records attributed to M Hishii.

5 recordsLinked to original sources

Immunohistochemical characterization of 'small, lymphoid-like cell populations' within germinomas: immunologic and molecular approaches to diagnosis.

Little is known to date about the biological and molecular characteristics of 'small lymphoid cells' within intracranial germinomas. Frozen sections from three germinoma specimens were evaluated immunohistochemically in order to identify phenotypic markers expressed on human lymphoid cells as well as intercellular adhesion molecules. In addition, T-cell receptor (TCR) variable alpha- and beta-chain mRNA expression was analyzed by polymerase chain reaction (PCR). The small cells stained faintly with anti-CD5 in two specimens, but were negative for the T cell specific markers, CD2, CD3, CD7, and CD8. In addition, these cells were weakly positive for CD11b (Mac-1) and CD54 (ICAM-1), but were negative for lymphocyte-specific CD11a (LFA-1) and CD11c (p150,95). No TCR V alpha or V beta gene expression was detected by PCR within these germinoma specimens. The small cells of germinomas with the cytologic appearance of lymphocytes are not derived from T-cells or other lymphocytic lineages.

Adolescent

Human glioma-derived interleukin-10 inhibits antitumor immune responses in vitro.

Intracranial malignant gliomas are sequestered from the immune system yet are associated with broad suppression of host immunocompetence. Immune system dysfunction in patients with gliomas seems to be related to inhibitory mediators produced by glioma cells. We investigated the physiological roles of glioma-derived interleukin (IL)-10 in Class II expression of monocytes, cytokine secretion from lymphocytes, and T cell proliferation in vitro. We could detect the messenger ribonucleic acid transcript of IL-10 in four gliomas by the reverse-transcribed polymerase chain reaction. Glioma-derived IL-10 greatly down-regulated human lymphocyte antigens-DR expression on monocytes. The inhibitory effect of IL-10 on interferon-gamma and tumor necrosis factor-alpha was neutralized by the anti-IL-10 monoclonal antibody; however, the inhibitory effect on IL-2 was not neutralized. Next, supernatants of glioma cells remarkably suppressed T cell proliferation in a dose-dependent fashion; however, this inhibitory effect was not restored by adding anti-IL-10 monoclonal antibodies. The supernatant also inhibited the allocytolytic activity of lymphocytes that were not neutralized by anti-IL-10 monoclonal antibody. IL-10 plays an important role in cytokine synthesis; nevertheless, impaired T cell responsiveness cannot be solely explained by glioma-derived IL-10.

Brain Neoplasms

Selective expression of interleukin-10 gene within glioblastoma multiforme.

Little information exists regarding which glioma cells are able to escape immune system detection and progress within the host. In order to elucidate some of the mediators which facilitate the growth and spread of glioma cells, the expression of cytokines, TNF-alpha, IL-6, gamma-IFN, IL-10, and GM-CSF, within 12 human glioma specimens was investigated by the polymerase chain reaction. The twelve patients with malignant glioma were categorized into a localized (n = 4) and an invasive glioma (n = 8) groups, mostly glioblastoma multiforme, based upon the CT and MRI scans. We examined the correlation between specific cytokine gene expression and the clinical category of each patient. The results showed that while IL-10 mRNA transcripts were expressed in most of the tumors from the invasive glioma group (7/8), they were not expressed in tumors from the localized group. On the other hand, gamma-IFN gene expression was more frequent in tumors from the localized group (3/4 vs 1/8 from the invasive group). The mRNA transcripts of IL-6 and GM-CSF were more frequently expressed in tumors from the localized group. No consistent pattern was seen in TNF-alpha gene expression between the two groups. Among the five cytokines studied, IL-10 mRNA was selectively expressed within invasive gliomas compared to less malignant, localized glioma group. Our results demonstrate specific cytokine mRNA profiles in glioma patients, which might have prognostic significance for immunotherapy.

Adult

[Unilateral supranuclear abducens palsy in a pineal tumor].

A 13-year-old boy complained of frequent headaches and diplopia on rightward gaze. A CT scan demonstrated hydrocephalus and a non-homogeneous enhancing mass in the pineal area, leading to a diagnosis of pineal tumor. The physical examination revealed no abnormalities. On neurological examination, there were a right homonymous hemianopsia and slight choked disc in both optic fundi. His right eye was slightly adducted on primary gaze. On right lateral gaze, his right eye could not move beyond the midline and showed gaze paretic nystagmus, whereas his left eye could move fully in all directions. The abducens palsy could be overcome by the oculocephalic maneuver or caloric test. Interestingly, his right eye could abduct when his left eye was covered. From these finding, this was labelled a supranuclear abducens palsy. The convergent nystagmus was observed. Rightward OKN (quick phase to right) of the right eye was abolished with and without the left eye covered, while leftward OKN of the right eye was preserved. Pursuit to right was disturbed. After removal of the tumor, the gaze palsies disappeared. It is postulated that the supranuclear lateral gaze palsy was caused by impairment of supranuclear control by involvement of lateral gaze pathways to gaze center coursing near the oculomotor nucleus.

Abducens Nerve