Search PubMed⌕ Search

Biomedical subjects

E Tani

Publications and source records attributed to E Tani.

At least 109 records · Page 6Linked to original sources
PubMed1990

Histamine acts directly on calcitonin gene-related peptide- and substance P-containing trigeminal ganglion neurons as assessed by calcium influx and immunocytochemistry.

Primary cultures of rat trigeminal ganglion cells were exposed to histamine, and the intracellular free-calcium concentrations, [Ca2+]i, were measured by the calcium-sensitive dye fura-2. Histamine (10(-6)-10(-2) M) increased the [Ca2+]i of the neurons. Pretreatment of the cells with histamine H1-receptor blocker pyrilamine (10(-4) M), or chelation of extracellular calcium, abolished the response; however, the response was not altered by pretreatment with H2-blocker cimetidine (10(-2) M). Thus, the increase in [Ca2+]i was due to the influx of extracellular calcium mediated by H1-receptor. Immunocytochemical analysis showed that these cultured cells that respond to histamine were identically calcitonin gene-related peptide (CGRP)- or substance P (SP)-like immunoreactive. The findings suggested that histamine released from mast cells directly affected CGRP- and SP-containing sensory neurons via H1-receptor, which convey nociceptive information.

Animals↗
PubMed1990

Amplification and expression of a multidrug resistance gene in human glioma cell lines.

Two human glioma cell lines were examined for multidrug resistance (MDR). A vincristine (VCR)-resistant glioma cell line showed a cross resistance to Adriamycin (doxorubicin, ADR) and etoposide (VP-16) to varying extents, suggesting the presence of MDR; the resistance to VCR was considerably decreased by calcium entry blockers. On the other hand, another VCR-sensitive glioma cell line exhibited no cross resistance to ADR or VP-16. Double minute chromosomes and homogeneously staining regions as well as clonal aberrations of chromosome 7 were not observed in cytogenetic studies of multidrug-resistant and multidrug-sensitive glioma cell lines. In Northern and Southern blot analyses, MDR gene 1 (MDR1) messenger ribonucleic acid (mRNA) was shown to be overexpressed without any amplification of the MDR1 gene in multidrug-resistant glioma cell lines as compared to multidrug-sensitive glioma cell lines. It would be reasonable to suggest that amplification of the MDR1 gene may not be a sine qua non for acquisition of MDR and that the MDR1 mRNA level may be correlated with the extent of MDR.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Lectin histochemistry of human gliomas.

Formalin-fixed and paraffin-embedded specimens of 24 human gliomas were examined histochemically with five lectins; concanavalin A (Con A), wheat germ agglutinin (WGA), Ricinus communis agglutinin 1 (RCA-1), peanut agglutinin (PNA), and Ulex europaeus agglutinin 1 (UEA-1). Although the staining intensity with lectins was variable, tumor cells in five astrocytomas, three oligodendrogliomas, six ependymomas, and one gliosarcoma, were generally positive for Con A, WGA, and RCA-1, and negative for PNA and UEA-1, whereas those in nine glioblastomas were usually positive for Con A and WGA and negative for RCA-1 and PNA as well as UEA-1. The malignancy in neoplastic astrocytes was correlated with the decrease in binding with lectins, especially RCA-1. Blood vessels, particularly the endothelial layers, in all gliomas were stained intensely with all lectins used. Macrophages showed two staining features with lectins; stippled and granular. The former macrophages were positive for Con A, WGA, RCA-1, and PNA, and negative for UEA-1, whereas the latter macrophages were positive for all lectins used. Thus, the staining characteristics with lectins of macrophages were different from those of any glioma cells and very useful for identification of macrophages in gliomas.

Brain Neoplasms↗
PubMed1989

Fine-needle aspiration cytology and immunocytochemistry of malignant non-Hodgkin's lymphoma in the oral cavity.

Fine-needle aspirates from 12 cases of malignant non-Hodgkin's lymphoma of the oral cavity were cytologically classified according to the Kiel classification. Ten lymphomas were high-grade and two were classified as being low-grade malignancies. Immunocytologic characterization on cytospin material showed that all cases were B-cell derived with monoclonal expression of immunoglobulin light chains. Surgical biopsy material was available for histologic diagnosis in 8 of 12 cases. In 5 of these, the cytomorphologic and the histologic diagnoses were in agreement. With respect to the other 3, one case was histologically classified as an unspecified malignancy and one as a centroblastic/centrocytic lymphoma, and in one case no malignant lesion could be found. The three cases were cytologically classified as large-cell centrocytic, centroblastic, and lymphoblastic lymphoma, respectively. We conclude that fine-needle aspiration cytology in conjunction with immunocytochemistry is a rapid, feasible, and atraumatic technique that is useful for diagnosing malignant lymphoma in the oral cavity.

Adolescent↗
PubMed1989

Estrogen receptors in fine-needle aspirates from metastatic lesions of gynecologic tumors.

The estrogen receptor content in metastases of gynecological tumors was analyzed with an immunocytochemical technique in material obtained by fine-needle aspiration. Eighteen patients with metastasis from ovarian (10 cases), endometrial (4 cases), and uterine cervical (4 cases) carcinomas were studied. Three metastases showed specific nuclear staining for estrogen receptors and they originated from primary tumors in the ovary, the cervix, and the endometrium. Thus needle aspirates can be used for cytomorphologic diagnosis as well as determination of estrogen receptors and their use has potential value when a decision must be made between hormonal therapy or chemotherapy in patients with generalized gynecological carcinomas.

Abdominal Neoplasms↗
PubMed1989

Biosynthesis of leukotrienes in canine cerebral vasospasm.

We produced cerebral vasospasm in 29 dogs by the "two-hemorrhage" method of intracisternal injections, 2 days apart, of autogenous arterial blood. Leukotriene (LT) C4, LTD4, and LTE4 were purified from incubated basilar artery, medulla oblongata, hypothalamus, median eminence, and blood clot from around the basilar artery using reverse-phase high-performance liquid chromatography, and the amount of each LT was quantified separately by bioassay with guinea pig ileum. The biosynthetic capacity for total LTs was approximately three times higher in the hypothalamus and median eminence than in the basilar artery and medulla oblongata in the eight normal dogs. In the dogs with subarachnoid hemorrhage, the biosynthetic capacity was increased significantly both before and 2 hours after the second injection of blood on Day 2 and was normal on Day 7 in the basilar artery and medulla oblongata, whereas the biosynthetic capacity was decreased significantly 2 hours after the first and second injections of blood and was increased significantly on Day 7 in the hypothalamus and median eminence. In blood clot the biosynthetic capacity was increased continuously after the first injection of blood. Thus, the biosynthetic capacity for total LTs showed a time- and tissue-specific change after subarachnoid hemorrhage.

Animals↗
PubMed1989

Effects of ML-9 on experimental delayed cerebral vasospasm.

Experimental delayed cerebral vasospasm was produced in a two-hemorrhage canine model. The spastic basilar artery was exposed via the transclival route under a surgical microscope and was dilated by the topical application of 1-(5-chloronaphthalenesulfonyl)-1H-hexa-1,4-diazepine (ML-9), a selective antagonist of myosin light chain kinase. Dilation was dose-dependent, with a median effective dose (+/- standard deviation) of 51.4 +/- 6.9 microM. In addition, 50 microM of ML-9 was injected into the cisterna magna until the intracranial pressure (ICP) reached 200 mm H2O for 30 minutes, including a complete reversal of angiographic delayed vasospasm in three of seven dogs; in contrast, 150 microM of ML-9 was infused at 1.52 ml/min into the vertebral artery for 30 minutes, producing little dilation of the spastic basilar artery. In another study, the intracisternal perfusion of 50 microM of ML-9 at 1.48 ml/min for 30 minutes in dogs with an ICP of less than 200 mm H2O produced no serious electroencephalographic abnormalities, and the mean arterial blood pressure and pulse rate remained normal; no neurological deficits or significant histological abnormalities ascribable to the intracisternal ML-9 were found.

Administration, Topical↗
PubMed1989

Modification of drug metabolic processes by compounds which intervene with the function of cytochrome P-450 as a mono-oxygenase and as an oxidase.

Pregnenolone-16 alpha-carbonitrile, spironolactone, tocopherol acetate and ethanol were tested for their effect on lipid peroxidation using microsomal membranes or linoleic acid as substrates and Fe++/ascorbate or Fe++ as electron sources. The steroids had no effect on lipid peroxidation, tocopherol and ethanol presented potent and mild antioxidant activity, respectively. Pregnenolone-16 alpha-carbonitrile, spironolactone, ethanol and tocopherol acetate were examined for the effects on the body's response to drugs. It was found that the former three agents increased the resistance to zoxazolamine, hexobarbital and chlorzoxazone and tocopherol acetate increased only that against chlorzoxazone. The test compounds were examined for their effect on the in vivo reduction of p-nitrobenzoate and the in vitro metabolism of zoxazolamine, hexobarbital, ethylmorphine and procaine. The two steroids and ethanol enhanced the metabolism almost in all cases, while tocopherol acetate increased only ethylmorphine N-demethylation very significantly.

Animals↗
PubMed1986

Fibrous xanthoma in the gasserian ganglion: case report.

Occurrence of fibrous xanthoma has been reported increasingly in the skull and the central nervous system, but is extremely rare in the gasserian ganglion. We report on the clinical presentation, radiological appearance, surgical treatment, and histological makeup of a fibrous xanthoma arising from the left gasserian ganglion.

Fibronectins↗
PubMed1985

Amyloidomas in the cerebellopontine angle and jugular foramen. Case report.

The 47-year-old man reported here showed large encapsulated masses in the left cerebellopontine angle and 6 years later in the enlarged left jugular foramen. Histologically, the tumors demonstrated a large deposit of amyloid composed of immunoglobulin light chain-derived proteins (AL). There was no evidence of chronic inflammatory or infectious processes or immunoglobulin abnormalities.

Amyloidosis↗
PubMed1985

Acromegaly associated with suprasellar and pulmonary hemangiopericytomas. Case report.

The authors report the case of a 35-year-old acromegalic woman who developed amenorrhea and decreased left vision, and who was found to have suprasellar and pulmonary hemangiopericytomas. Total removal of the suprasellar hemangiopericytoma resulted in normalization of the plasma human growth hormone (GH) level and a marked decrease in size of the pulmonary hemangiopericytoma. Immunoperoxidase studies for GH and human hypothalamic growth hormone-releasing factor (GHRF) demonstrated immunoreactive intracellular GH only in the suprasellar hemangiopericytoma, with no immunoreactive intracellular GHRF evident in either the suprasellar or pulmonary hemangiopericytoma.

Acromegaly↗
PubMed1985

Potentiation of vincristine effect in human and murine gliomas by calcium channel blockers or calmodulin inhibitors.

The effects of calcium channel blockers and calmodulin inhibitors on vincristine cytotoxicity were studied in vitro with five glioma cell lines: three human glioblastomas, one rat glioma, and one mouse ependymoblastoma. One human glioblastoma and the rat glioma were resistant to vincristine in contrast to other glioma cells. The resistance to vincristine was considerably decreased by nontoxic or marginally toxic concentrations of calcium channel blockers or calmodulin inhibitors, although the former was more effective than the latter. In the presence of verapamil, the vincristine cytotoxicity, as measured by cell doubling times, increased 90- and 84-fold in the vincristine-resistant human glioblastoma and rat glioma, respectively. The decrease in the resistance to vincristine was related to a marked increase in the intracellular level of that drug, probably mediated by inhibiting its outward transport. The in vivo studies showed that verapamil or nicardipine administered daily with vincristine for 10 days significantly enhanced the chemotherapeutic effect of vincristine in an intracranially transplanted rat glioma model. An approximately 32% to 118% increase in life span occurred with 15 mg/kg/day of verapamil, depending on the doses of vincristine.

Animals↗
PubMed1984

Immunohistochemical study of fibronectin in hemangioblastomas and hemangiopericytomas.

Eight hemangioblastomas and two hemangiopericytomas were studied using indirect immunoperoxidase stains for fibronectin (FN) and glial fibrillary acidic protein (GFAP) in formalin-fixed, paraffin-embedded surgical specimens. Stromal cells in hemangioblastomas were GFAP-negative and showed variable FN expression, while GFAP-positive cells were FN-negative, thus suggesting that the stromal cells are not derived from astrocytes. Hemangiopericytoma cells were poorly to intermediately FN-positive. The origin of stromal cells is discussed in the light of their fine structure and the immunohistochemical stains with other cell markers.

Brain Neoplasms↗
PubMed1984

Neoplastic cerebral aneurysm from lung cancer. Case report.

A 56-year-old man with lung cancer developed a massive intracerebral hematoma resulting from rupture of a small neoplastic aneurysm in a cortical branch of the left posterior temporal artery. Histologically, undifferentiated squamous cells formed an embolus in the aneurysm and destroyed the aneurysm wall. No tumor mass was evident around the aneurysm.

Brain Neoplasms↗