Shinya Oshiro

Modified immunoregulation associated with interferon-γ treatment of rat glioma

Abstract Little is known about modulation by cytokines of major histocompatibility complex (MHC) antigen expression on intracranial tumors in vivo. The ability of cytokines to up-regulate MHC class-1 (MHC-1) antigen expression was investigated first in vitro using three rat glioma cell lines. Immunohistochemistry showed that incubation with recombinant rat interferonγ (rrIFNγ) increased MHC-1 antigen expression in RG2, C6, and 9L cell lines. Flow cytometric analysis revealed different baseline levels of MHC-1 antigen expression in each line (RG2 lowest, C6 highest), and that these levels increased in all lines after stimulation with 100 U ml–1 or more of rrlFNγ. The antitumor effect of rrIFNγ in vivo was evaluated by assessing survival of rats with implanted intracerebralRG2 gliomas after intracarotid infusion of rrIFNγ. A high dose of rrIFNγ (2.4×105 U kg–1) significantly increased the survival, compared to control (p<0.02). Intracarotid pre-treatment with the bradykinin analogue RMP-7 did not further increase survival. Immunohistochemical staining of tumor sections after in vivo rrIFNγ infusion showed no clear increase in MHC-1 antigen expression on tumor cells but increased staining for ED2 antigen within tumor tissue, presumably from perivascular cells with MHC class-2 antigen.

A Case Report of Caudal Regression Syndrome Associated with an Intraspinal Arachnoid Cyst

We report here a rare case of caudal regression syndrome associated with an intraspinal arachnoid cyst. The patient was a 6-month-old baby girl with multicomplex congenital abnormalities: sacrococcygeal dysgenesis and ventral curvature, large terminal cyst (myelocystocele), spinal arachnoid cyst, cerebellar hypertrophy (suspected), high imperforate anus, partial dysgenesis of the large intestine, omphalocele, atresia of the vagina, bilateral incomplete ureter duplication, incomplete pseudoduplicated bladder and bilateral talipes equinovarus. We performed plastic repair of the myelocystocele and perineal lesion for caudal regression syndrome and partial removal of the cyst wall for the intraspinal arachnoid cyst. She has been well for 3 years postoperatively, and her mental development is normal.

A case of a heavily pigmented orbital melanocytoma

We present an extremely rare case of an orbital melanocytoma that occurred in a 51-year-old man. The patient suffered from diplopia and mild exophthalmos of the right eye for 2 months. Brain magnetic resonance imaging showed a well-demarcated round mass 3.5 cm in diameter in the right orbit. We performed total resection of this tumor. Histological findings revealed a proliferation of large polygonal cells with fine pigment granules in the cytoplasm and prominent nucleoli. Although these tumor cells revealed immunohistochemical reactivity in HMB-1, there was no S-100 or Melan A antibody reactivity. Also, there were no malignant findings of nuclear polymorphism, mitoses, or necrosis. The brown pigments were confirmed to be melanin by bleaching and the Fontana-Masson silver stain method. The MIB-1 labeling index was less than 1%. This tumor also consisted of 50% melanophages, which revealed immunohistochemical reactivity in CD68, CD163, and in (1-AT antibodies. These histological findings led us to diagnose an orbital melanocytoma with partial tumor regression.

Pilomyxoid Astrocytomas: Chemotherapy

Pilomyxoid astrocytoma (PMA) is a variant of pilocytic astrocytoma (PA). However, PMA shows a higher rate of recurrence and dissemination in cerebrospinal fluid (CSF) than does pilocytic astrocytoma (PA). PMA occurs predominantly in the hypothalamic/chiasmic region, and thus it is usually treated with chemotherapy following surgical biopsy. We discuss the treatment of PMA. Materials and Methods: Between 1992 and 2009, the authors treated 5 patients, 2 males and 3 females, ranging in age from 3 months to 11 years. Results: Three patients showed CSF dissemination on the initial radiographic examination. All patients received chemotherapy; the most commonly used drug combination was that of cisplatin (CDDP)/carboplatin (CBDCA) and etoposide. If these drugs were unsuccessful, they were changed, or other drugs were added to the combination. After chemotherapy, four patients showed remarkable tumor regression. Nevertheless, one patient died due to tumor progression 22 months after initial diagnosis. Conclusion: Although our series comprised a small number of patients, treatment of PMA with chemotherapy appeared to be of value. Even if initial chemotherapy is ineffective, we recommend continued CDDP/CBDCA-based chemotherapy with new drug combinations.