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Biomedical subjects

T Shimoda

Publications and source records attributed to T Shimoda.

At least 199 records · Page 11Linked to original sources
PubMed1988

In vitro red tide toxin effects on human bronchial smooth muscle.

Airborne Ptychodiscus brevis toxin (PBTX), produced by Ptychodiscus brevis (Florida red tide), induces cough, rhinorrhea, watery eyes, and sneezing in normal individuals and wheezing in subjects with asthma. The mechanism of PBTX-induced contractile response has been investigated by the authors in vitro in dog and rat tissue. PBTX stimulates neuronal sodium channels, resulting in activation of autonomic cholinergic and adrenergic nerve endings in canine upper and lower airway smooth muscle and in rat vas deferens, respectively. This article concerns the investigation of the effect and mechanism of action of PBTX on human airways in order to determine the unique role of the toxin in the pathogenesis of asthma. PBTX elicited contractions of isolated human airway smooth muscle with a threshold concentration of 0.1 micrograms/ml, very similar to values obtained in canine lower airways. Pharmacologic analysis demonstrated that atropine (10(-6) mol/L) blocked the response to both PBTX and acetylcholine; tetrodotoxin (10(-7) mol/L) blocked PBTX but not acetylcholine; and verapamil (10(-5) mol/L) attenuated but neostigmine (10(-8) mol/L) potentiated the response to PBTX. Other selected blockers did not affect the PBTX response. These data indicate that PBTX produces contraction of human lower airway smooth muscle via stimulation of cholinergic nerve fiber sodium channels. The concept that PBTX triggers asthma through this mechanism is strengthened by these results.

Acetylcholine↗
PubMed1988

[Establishment and characterization of a new SCC antigen producing cell line (HCS-2) from a carcinoma of the uterine cervix].

The cell line designated HCS-2 established from a squamous cell carcinoma of the uterine cervix has been subcultivated 77 times since Nov. 8, 1983. The cultured cells appear epithelial in shape, with a pavement-like arrangement and grow without contact inhibition. In electron microscopy, the cells are characterized by desmosomal cell contacts and a few tonofilaments. The cells are transplanted subcutaneously to nude mice and produce tumor which resembles the original tumor of large cell non-keratinizing squamous cell carcinoma. The growth rate of subculture has increased gradually, and population doubling time of cells at 17th passage was about 65 hours. The chromosome studies show aneuploidy and chromosomal number was mainly from hypertriploid to hypotetraploid range. The modal number of cells at 33rd passage was 81. Specific marker chromosome is not realized. The production of SCC antigen is detected from the cells and the amount of SCC antigen in cultured media was recorded from 1.5 to 2.0 ng per 1 x 10(4) cells for 48 hours. CEA synthesis is also confirmed immunohistochemically.

Adult↗
PubMed1988

[Effects of cepharanthin on leukopenia and thrombocytopenia caused by CDDP-ACR-CPA therapy of ovarian cancer].

Effects of cepharanthin (50 mg/day, i.v.) an alkaloid of bis-coclaurin type, were studied on leucopenia and thrombocytopenia caused by CDDP-ACR-CPA (CAP) therapy against ovarian cancer. The study was carried out with 44 therapy courses on 17 patients of ovarian cancer receiving CAP administration. Nineteen of the 44 courescin loaded cepharanthin. The minimum number of leucocytes was found on 15.2 +/- 4.4 and 17.2 +/- 2.1 days after CAP-administration with and without cepharanthin, respectively. Leucocyte count 21 days after CAP-administration compared to that before the administration were 90.1 and 56.8% in cepharanthin and non-cepharanthin groups, respectively, which indicate a significant difference (p less than 0.05). As to the platelet count, cepharanthin group also showed attendant toward earlier recovery of thrombocytopenia than non-cepharanthin group. We conclude that the administration of cepharanthin during CAP therapy promotes the recovery from leucopenia and thrombocytopenia.

Adult↗
PubMed1987

Occupational asthma caused by isonicotinic acid hydrazide (INH) inhalation.

Occupational asthma caused by isonicotinic acid hydrazide (INH) inhalation occurred in a 26-year-old female hospital pharmacist after symptoms of allergic rhinitis. Intradermal, inhalation, and Prausnitz-Küstner tests were performed with INH dissolved in saline, INH dissolved in the subject's serum and incubated at 25 degrees C for 4 hours, and an INH conjugate with human serum albumin. An INH conjugate with bovine serum albumin was also used in the prick tests alone. All preparations caused rapid positive skin reaction in the patient. Prausnitz-Küstner tests on the subject's mother were also rapidly positive. Furthermore, positive results were obtained not only in the inhalation tests with the three antigens but also in the environmental provocation tests. These results strongly suggested that the asthmatic symptoms of the subject were not caused by physical irritation from INH or other drugs and might be mediated by an IgE antibody specific to INH, a suggestion subsequently confirmed by in vitro enzyme-linked allergosorbent test for the antibody previously reported. This is the first precise description of INH-induced bronchial asthma, and the four kinds of INH preparations used in these tests might be very useful as tools of clinical diagnosis in INH allergy.

Adult↗
PubMed1987

Isonicotinic acid hydrazide as an antigen.

Detection by in vitro serologic techniques of circulating antibody directed against isonicotinic acid hydrazide (INH, known as isoniazid) in humans has not been reported. In the past few months, however, sera from a patient with a recent history of isoniazid hypersensitivity of the immediate type have been studied, and reaginic antibodies (IgE) specific to INH were detected by means of an enzyme-linked allergosorbent test. Preliminary enzyme-linked allergosorbent tests also demonstrated that INH-specific IgE occurred in the serum of two of 150 patients with tuberculosis who had been treated with INH.

Adult↗
PubMed1987

Lower airway smooth muscle contraction induced by Ptychodiscus brevis (red tide) toxin.

Ptychodiscus brevis toxin (PBTX) is produced by the organism Ptychodiscus brevis. This toxin causes a phenomenon that has come to be known as Florida red tide. It also stimulates neuronal sodium channels, resulting in activation of the cholinergic and adrenergic nerve endings of the autonomic nervous system in upper airway smooth muscle and rat vas deferens, respectively, as previously reported. It is the cholinergic stimulating action that has been implicated as a possible "triggering" event in bronchial asthma. This article concerns the investigation of whether PBTX may also affect lower airways and by what mechanism any contractile response to PBTX in lower airways may be induced. PBTX was found to elicit contractions in isolated canine lower airway smooth muscle. The threshold concentration was 0.15 microgram/ml, the peak response occurred at 6.0 micrograms/ml, and the concentration causing half-maximal response of the group was 0.57 microgram/ml. Pharmacologic analysis demonstrated that atropine (10(-6) mol/L) blocked the response to both PBTX and acetylcholine, tetrodotoxin (10(-7) mol/L) blocked the response to PBTX but not to acetylcholine, and verapamil (10(-5) mol/L) blocked the response to PBTX and reduced the response to acetylcholine. Four consecutive contractile responses to PBTX (3 micrograms/ml) produced rapid tachyphylaxis. The fourth contraction was 60% less than the initial response. A fifth response to PBTX after exposure to indomethacin (2.8 X 10(-6) mol/L) was increased and resulted in a contraction that was only 25% less than the initial response. The exogenous addition of prostaglandins (PG), PGE1 and PGE2, to indomethacin-treated lower airway strips selectively suppressed the contractile response to PBTX. Other PGs tested (PGA2, PGB2, PGD2, PGF2 alpha and PGI2) did not affect the PBTX response. These results indicate that PBTX produces spasm in lower airway smooth muscle and that it does this by stimulation of sodium channels in the cholinergic nerve fibers. The results also demonstrate a rapid reduction in the contractile response to PBTX. The results also demonstrate that the reduction is mediated by PGs of the E series.

Acetylcholine↗
PubMed1987

Argyrophil, non-argentaffin carcinoids of the appendix vermiformis. Immunohistochemical and ultrastructural studies.

Five argyrophil, non-argentaffin classical carcinoids of the appendix were found in 19 appendiceal classical carcinoids and were investigated histochemically, immunohistochemically and ultrastructurally. All tumors consisted entirely of argyrophil cells. Three of the five carcinoids were composed almost totally of peptide YY cells and were negative for serotonin. One of them consisted of peptide YY cells (60%), somatostatin cells (40%), and a few cells with glucagon-like immunoreactivity (GLI). The remaining one without peptides was homogeneously immunoreactive for serotonin alone. Ultrastructurally, each of the four peptide-positive carcinoids was composed of one kind of endocrine cell type with round secretory granules. Average diameter of granules were 150, 160, 190, and 210 nm, respectively. The non-argentaffin, serotonin-positive carcinoid showed predominant round secretory granules and a few irregular ones, both being 150 nm in largest diameter. It is suggested that the argyrophil, non-argentaffin carcinoids of the appendix are subdivided into two groups; carcinoids composed mainly of peptide (especially, peptide YY)-positive cells with round granules of D1 and/or L cell type and those of serotonin-positive cells with pleomorphic granules of ECn cell type.

Adolescent↗
PubMed1987

[A case report of malignant schwannoma originating from the bone].

While malignant schwannoma is encountered frequently as soft tissue sarcomas, it rarely is found to originate in the bone. We have had a case of malignant schwannoma originating from the tibia of a 47-year-old man. He died from uremia, that resulted from lung, spinal vertebral body, and lymph nodes metastases, despite surgical treatment and chemotherapy. In cases of rare bone tumors, the clinical diagnosis of tumoral manifestations originating in the bone is more important than the histopathological diagnosis.

Bone Neoplasms↗
PubMed1986

Immunoreactive somatostatin and calcitonin in pulmonary neuroendocrine tumor.

A well-differentiated neuroendocrine carcinoma of the lung that secreted immunoreactive somatostatin (IR-SRIF) and IR-calcitonin (CT) in a 72-year-old women is described. The plasma concentrations of IR-SRIF (57.5 pg/ml) and IR-CT (340 pg/ml) before operation were significantly higher than the respective normal ranges. After resection of the tumor, the plasma CT level (105 pg/ml) decreased to within the normal range, and the SRIF level (32.7 pg/ml) also decreased, but was still abnormally higher, which suggested the presence of an unidentified remnant of the tumor. Abnormal accumulation of technetium 99m (99mTc) in the lumbar vertebrae was found 6 months after the operation, which indicated a metastatic tumor. The tissue concentrations of IR-SRIF and IR-CT were 103 and 94 ng/g wet weight, respectively, and SRIF-IR tumor cells and CT-IR tumor cells were demonstrated immunohistochemically. On gel-filtration chromatography of the tumor tissue, two peaks of SRIF immunoreactivity were eluted in the positions of synthetic SRIF-28 and SRIF-14, respectively. Conversion of SRIF-28 to SRIF-14 was suggested from results on changes in the two IR-SRIF components during incubation with a crude enzyme preparation extracted from the tumor tissue.

Aged↗
PubMed1986

Peptide YY immunoreactive cells in gastrointestinal carcinoids: immunohistochemical and ultrastructural studies of 60 tumors.

The distribution and frequency of peptide YY (PYY) cells in 60 gastrointestinal carcinoids and in the nonneoplastic mucosa around the carcinoids were studied by an indirect immunoperoxidase method with anti-PYY serum. Additionally, the endocrine cell type of the PYY cells in appendiceal and rectal carcinoids was assessed by transmission electron microscopy. A few PYY cells were present in specimens of nonneoplastic mucosa from stomach, duodenum, jejunum, ileum, and appendix, with an abundance of these cells in rectal mucosa. Peptide YY cells were found in one of 13 gastric, one of 13 duodenal, one of one jejunal, zero of two ileal, three of 11 appendiceal, and 16 of 20 rectal carcinoids. All but one of the PYY-positive carcinoids were argyrophil carcinoids. Peptide YY cells in the gastric, duodenal, and jujunal carcinoids were present in small numbers. The three PYY-positive carcinoids of the appendix were composed almost totally of PYY cells, whereas those of the rectum generally contained only sporadic PYY cells. The peptide YY cells observed ultrastructurally contained almost round secretory granules (about 160 nm in average diameter), which were most consistent with D1(H) cell type granules with respect to shape and average diameter. This is the first systematic immunohistochemical and ultrastructural study of PYY cells in gastrointestinal carcinoids.

Carcinoid Tumor↗
PubMed1986

Immunohistochemical study on the distribution and significance of mononuclear cells in human breast carcinoma.

Lymphocyte subsets in the tumor nests of breast carcinoma were immunohistochemically investigated and a quantitative analysis was added. The majority of cases showed predominance of T cell and suppressor T cell (T8). A decrease in number of lymphocyte subsets and the helper T (T4)/T8 ratio in the stroma of tumor nests correlated well with the progression of clinical stage and the presence of metastasis. This correlation could not be found in the peripheral region of the tumor nests. Macrophages and NK cells were infrequently observed only in the peripheral region of ductal carcinoma. T cell infiltration was prominent in medullary carcinoma with lymphocyte infiltration (MC), and macrophages, NK cells, and T zone histiocytes were frequently encountered. For the purpose of knowing the activity of T cells, IL-2 receptor (Tac) and transferrin receptor were examined immunohistochemically. The fact that a few activated T cells were found only in the peripheral region of tumor nest suggested the local immune response in ductal carcinoma not to be so active as to reject the tumor cells. Since numerous activated T cells were recognized in the tumor nests of MC, this type of breast carcinoma was thought to have a higher immune reactivity. There was little evidence indicating NK cells to play a role for natural cytotoxicity in breast carcinoma.

Adenocarcinoma, Mucinous↗
PubMed1986

The histogenesis and early invasion of gastric cancer.

A three-dimensional analysis of the histogenesis of gastric cancer was made by examining minute, microscopic lesions of less than 500 mu. Cancer develops from the generative cell zone (G-zone) of the atrophic gastric glands and intestinal metaplastic glands. They then bud or branch and infiltrate into the propria interstitial tissue. The G-zone of the cancerous glands showed marked expansion with complete loss of normal cell kinetics of gastric glands and with hardly any signs of differentiation into pyloric glands. In the adjacent glands there were also expansion of the G-zone and formation of loop-shaped glands with abnormal branching and anastomosis sometimes leading to the formation of a network of glands. These changes are compatible with those of abnormal differentiation accompanying atrophy or intestinal metaplasia and are considered to express a preinvasive cancer.

Adenocarcinoma↗