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Biomedical subjects

Y Amano

Publications and source records attributed to Y Amano.

At least 91 records · Page 5Linked to original sources
PubMed1993

Malignant paraganglioma presenting as Cushing syndrome with virilism in childhood. Production of cortisol, androgens, and adrenocorticotrophic hormone by the tumor.

BACKGROUND: A 12-year-old girl with intractable retroperitoneal paraganglioma experienced increased appetite, acne, obesity, "moon face," and enlargement of the clitoris during the course of the tumor. Plasma cortisol, serum testosterone, and dehydroepiandrosterone sulfate (DHEA-S) levels were increased to 34.1 micrograms/dl, 2.0 ng/ml, and 6.628 ng/ml, respectively. Adrenocorticotrophic hormone (ACTH) levels were not increased, and results of dexamethasone suppression tests were negative. Her condition was diagnosed as Cushing syndrome with virilism. Plasma cortisol levels were increased to a level of 107.1 micrograms/dl before death. METHODS: Tumor samples were obtained at the time of autopsy. The concentrations of cortisol, androgens, ACTH, and catecholamines were assayed in the tumor extracts. The indirect immunoperoxidase procedure was performed on fixed tissues for cortisol, DHEA-S, testosterone, and ACTH. RESULTS: Extracts of the tumor masses contained steroid hormones: the amount of immunoreactive cortisol was 1.64 micrograms/g wet weight; the amount of immunoreactive testosterone was 25.60 ng/g wet weight; immunoreactive DHEA-S, 579.00 ng/g wet weight; and immunoreactive ACTH, 891.00 pg/g wet weight in the metastatic mass of the lung. Immunohistochemically, immunoreactive cortisol, testosterone, and DHEA-S were detectable in the tumor cells. The adrenal gland was atrophic. CONCLUSIONS: The patient is the first reported with malignant paraganglioma with the capacity to produce cortisol, androgens, and ACTH.

Adrenocorticotropic Hormone↗
PubMed1993

[CT and MR imaging of post-aortic left brachiocephalic vein].

The usefulness of CT and MR imaging (MRI) for the diagnosis of post-aortic left brachiocephalic vein (PALBV) is discussed. The subjects of the present study consisted of five patients with PALBV, two males and three females, aged four months to sixty years. Chest CT and MRI were performed as a follow-up study of other intrathoracic lesions in two cases, and for further examination of congenital heart diseases in two infant cases. The other patient underwent both CT and MRI to evaluate sporadic chest pain. Therefore, all PALBV were found incidentally. PALBV passes below the aortic arch in front of the trachea, draining the superior vena cava behind the ascending aorta. This finding was particularly well documented on consecutive coronal sections on MRI. In patients with intrathoracic malignant or specific inflammatory lesion, differentiation between PALBV and lymphadenopathy is necessary for treatment. From our experience, marked enhancement on CT and no signal intensity on MRI in PALBV could differentiate this anomaly from mediastinal lymphadenopathy. In two infantile cases with congenital cardiovascular anomalies such as tetralogy of Fallot, right aortic arch and pulmonary arterial stenosis, MRI was found to be superior to CT in demonstrating these anomalies.

Adult↗
PubMed1993

Chondrosarcoma of the nasal septum: surgical considerations on Le Fort I osteotomy.

A case of chondrosarcoma of the nasal septum extending into the entire nasopharynx sphenoid sinus and skull base is presented. These cartilaginous tumors are rate in the head and neck, with only 28 reported in the nasal septum. They arise in tissues known to be formed of cartilage, and in the present case tumour presumably originated from the perpendicular lamina of the septum. The treatment of choice is wide surgical excision, which requires an adequate approach for gaining the widest possible exposure of tumor. Surgical considerations are discussed.

Chondrosarcoma↗
PubMed1993

Improvement of neutropenia and neutrophil dysfunction by granulocyte colony-stimulating factor in a patient with glycogen storage disease type Ib.

Patients with glycogen storage disease type Ib (GSD Ib) suffer from recurrent bacterial infections due to neutropenia and neutrophil dysfunction. To improve the quality of life in a 9-year-old boy with GSD Ib, we subcutaneously administered recombinant human granulocyte colony-stimulating factor (G-CSF). Daily injections of 100 micrograms/m2 of G-CSF significantly increased absolute neutrophil counts and augmented neutrophil mobility. The patient was then treated with 70 and 100 micrograms/m2 of G-CSF daily and twice-weekly. The treatment maintained absolute neutrophil counts at significantly higher levels than those without treatment for 22 months and markedly decreased the frequency of infections and the necessity for hospitalisation. Weekly injections of 70 micrograms/m2 of G-CSF were less efficient. No adverse effects were observed during treatment. These findings indicate that daily and twice-weekly treatment with G-CSF of long duration are safe and effective for patients with GSD Ib. G-CSF may be a useful therapeutic agent in patients with neutrophilic impairment as a consequence of a metabolic disorder.

Cell Movement↗
PubMed1993

Hypercalcemia associated with all-trans-retinoic acid in the treatment of acute promyelocytic leukemia.

Recent reports have described clinical benefits of all-trans-retinoic acid (ATRA) therapy for acute promyelocytic leukemia (APL). This paper describes severe hypercalcemia (serum calcium: 18.7 mg/dl) in association with ATRA treatment in a 14 year old girl with APL. Serum parathyroid hormone (PTH) concentrations were normal (0.21 ng/ml), which precludes the possibility of primary hyperparathyroidism or ectopic PTH secretion as a cause of the hypercalcemia. As for the factors which can accelerate mineral resorption, there were no apparent increases in the levels of PTH-related protein (PTH-rP), prostaglandins and vitamin D metabolites. In our in vitro experiment, ATRA did not stimulate the leukemic cells to produce PTH-rP. We speculate that ATRA, like PTH, may increase osteoclastic activity and induce hypercalcemia.

Adolescent↗
PubMed1993

Stem cell factor enhances the growth of primitive erythroid progenitors to a greater extent than interleukin-3 in patients with aplastic anaemia.

We examined the combined effects of stem cell factor (SCF), or interleukin-3 (IL-3) with erythropoietin on the development of haemopoietic progenitors in 19 patients with aplastic anaemia (AA) and eight normal controls by using an in vitro clonal assay. SCF significantly enhanced the growth of total erythroid colonies (erythroid bursts, mixed colonies) in 11 patients and all normal controls, whereas IL-3 did so in only three patients. The number of SCF- or IL-3-dependent erythroid colonies was substantially lower in AA patients than in the controls. Comparison of the capacity of SCF and IL-3 to increase total erythroid colony growth indicated that half of the AA patients responded more strongly to SCF than the normal controls, while few patients responded in such a manner to IL-3. These findings suggest that SCF in vivo will have a more dramatic effect than IL-3 in improving anaemia in patients with AA.

Adolescent↗
PubMed1993

Quaternary diltiazem can act from both sides of the membrane in ventricular myocytes.

A quaternary derivative of diltiazem (quat-DTZ) was tested to determine whether diltiazem approaches L-type Ca2+ channels from the outside or inside of the cell membrane. In single ventricular myocytes, both extra- and intracellular application of quat-DTZ effectively blocked the L-type Ca2+ channel current, whereas D890 was effective only when applied intracellularly. These results strongly suggest that diltiazem binds to the channel from the outside as well as the inside of the membrane in a manner different from that of phenylalkylamines.

Animals↗
PubMed1993

[Abnormalities in regulation system of granulopoiesis].

We studied the effects of several cytokines on the development of granulocyte-macrophage (GM) progenitors using the serum-deprived culture. SCF plays an important role in the GM-CSF- or IL-3-dependent production of neutrophils and macrophages. In vitro colony assay also suggests an increase in sensitivity of GM progenitors to cytokines (GM-CSF, IL-3, G-CSF and/or SCF) in a patient with juvenile chronic myelogenous leukemia. A high level of serum IFN-gamma was associated with leukopenia and thrombocytopenia in a patient with hemophagocytic syndrome. Based on the evidence that IFN-gamma significantly inhibited the proliferation of GM progenitors, IFN-gamma-mediated suppression was suggested as one of the mechanisms causing cytopenia. In patients with aplastic anemia and neutropenia, an increase of serum G-CSF levels was observed when neutrophils decreased remarkably in number. However, the serum SCF levels were constant in these patients. A failure of SCF to enhance colony growth in some patients with aplastic anemia implies qualitative abnormalities of hematopoietic progenitors.

Anemia, Aplastic↗
PubMed1993

Possible role of stem cell factor as a serum factor: monoclonal anti-c-kit antibody abrogates interleukin-6-dependent colony growth in serum-containing culture.

The monoclonal rat anti-c-kit antibody (ACK2), which abrogates colony growth supported by stem cell factor (SCF), significantly inhibited the interleukin-6 (IL-6)-dependent growth of hematopoietic progenitors derived from spleen cells of normal and 5-fluorouracil (5-FU)-treated mice and from bone marrow cells of normal mice in serum-containing culture. The numbers and types of colonies supported by IL-3, granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF), however, were not influenced by the addition of ACK2 to the cultures of the bone marrow cells from normal mice. In replating experiments with pooled blast cells, ACK2 caused a partial, but significant, inhibition of GM colony growth supported by a combination of IL-6 and fetal bovine serum (FBS), which suggests that FBS is one source of the SCF activity. Conversely, the addition of SCF or FBS with IL-6 to a serum-free culture had significant synergistic effects on the total number of colonies derived from post-5-FU spleen cells and from pooled blast cells. The dose response study showed that the ability of 30% FBS to interact with IL-6 on the colony growth by post-5-FU spleen cells was equivalent to that of approximately 5 ng/mL SCF. These findings suggest that c-kit plays an important role in the growth of hematopoietic progenitors responding to IL-6, and that SCF in the serum affects the development of hematopoietic progenitors in serum-containing cultures.

Animals↗
PubMed1993

Hemorrhage from spontaneous rupture of a parathyroid adenoma (a case report).

A case of extracapsular hemorrhage from spontaneous rupture of a parathyroid adenoma is reported. In the case presented here, adenoma was revealed by a sudden onset of a huge ecchymosis and hematoma of the entire anterior neck and right chest, causing recurrent nerve paresis. These cases of hemorrhage from rupture of silent parathyroid adenoma mimicking a dissecting thoracic aortic aneurysm are discussed.

Adenoma↗
PubMed1993

[RI venography for retroperitoneal hematoma following anticoagulant therapy for IVC filter thrombosis].

We presented a case of massive retroperitoneal hematoma owing to anticoagulant therapy for IVC filter thrombosis. CT showed the hematoma as high density area. RI venography demonstrated the thrombosis and collateral veins, suggesting the sites of anticoagulant induced bleeding and resultant hematoma. We suppose that RI venography is useful for the follow-up study of the IVC filter inserted cases.

Aged↗
PubMed1993

[Clinical studies on ceftriaxone in respiratory tract infections. CTRX Study Group].

We report that the results of clinical studies on ceftriaxone (CTRX) in respiratory tract infections (RTIs). Clinical efficacies and side effects of CTRX were as follows; 1. Clinical efficacies of CTRX in a total of 61 cases with RTIs were excellent in 11 cases, good in 23, fair in 11, poor in 12 and unknown in 4. Thus the overall clinical efficacy rate was 59.6%. In cases of patients with lung cancers, the efficacy rate was 42.9%. 2. Clinical efficacy rates with once daily dosage were 50.0% with a dose level of 1 g CTRX and 54.8% with that of 2 g CTRX. 3. Side effects were observed in 2 cases (3.1%) and laboratory abnormalities were observed in 1 case (1.6%). They were not serious, however. These data suggest that CTRX is one of the useful cephalosporins in treatment of RTIs.

Adult↗
PubMed1993

Inhibition by glucocorticoids of the formation of interleukin-1 alpha, interleukin-1 beta, and interleukin-6: mediation by decreased mRNA stability.

The mechanism by which glucocorticoids inhibit interleukin (IL)-1 and IL-6 formation in human monocytes and a promonocytic cell line activated by Escherichia coli lipopolysaccharide was analyzed. Dexamethasone (DEX) decreased levels of IL-1 alpha and IL-1 beta mRNAs in a dose-related fashion. The DEX-induced decrease in levels of IL-1 alpha and IL-1 beta mRNAs was abolished by the steroid receptor antagonist RU486. The levels of IL-1 alpha and IL-1 beta proteins within the cells and of IL-1 beta in the culture medium were decreased by DEX to comparable extents, so that DEX had no detectable effect on cytokine secretion. DEX did not influence lipopolysaccharide-induced transcription of the IL-1 beta gene in monocytes. However, DEX markedly decreased the stability of IL-1 beta mRNA, as shown both by steady state measurements and by pulse-labeling. DEX-induced instability of IL-1 beta mRNA required protein synthesis. DEX was also found to be a potent inhibitor of IL-1-induced expression of the IL-6 gene in connective tissue-type cells from the synovium of patients with rheumatoid arthritis. Inhibition of the formation of proinflammatory cytokines, including IL-1 beta and tumor necrosis factor-alpha, is a mechanism by which glucocorticoids exert anti-inflammatory effects. Inhibition by glucocorticoids of the expression of IL-1 alpha in antigen-presenting cells could decrease the capacity of the cells to stimulate the proliferation of T lymphocytes. This activity, as well as inhibition of the production and effects of IL-1 beta, including induced formation of IL-6 and of certain lymphokines, could explain the immunosuppressive effects of glucocorticoids.

Cell Line↗
PubMed1992

Stem cell factor enhances proliferation, but not maturation, of murine megakaryocytic progenitors in serum-free culture.

The effects of recombinant rat stem cell factor (SCF/c-kit ligand) on murine megakaryocytopoiesis were studied using partially purified bone marrow cells derived from normal and 5-fluorouracil (5-FU)-treated mice in a serum-free culture system. SCF alone did not support the formation of megakaryocyte (M) and granulocyte-macrophage-megakaryocyte (GMM) colonies. However, the addition of SCF to cultures containing interleukin-3 (IL-3) resulted in a significant increase in the number of M and GMM colonies formed by bone marrow cells from normal mice, whereas IL-6 augmented only M colony growth. The stimulatory effect of SCF was approximately three to four times as high as that of IL-6 on the primitive progenitors capable of megakaryocytic-lineage expression derived from 5-FU-treated mice. In addition, SCF, but not IL-6, significantly increased the number of constituent cells in the individual M colonies supported by IL-3. On the other hand, SCF did not exert any effect on the size and DNA content of megakaryocytes in IL-3-dependent M and GMM colonies, whereas IL-6 enhanced the maturation of megakaryocytes. These results suggest that SCF stimulates the proliferative process in megakaryocytic progenitors and that the main activity of IL-6 is the promotion of megakaryocyte maturation.

Animals↗
PubMed1992

Photolabeled sites with a tetrodotoxin derivative in the domain III and IV of the electroplax sodium channel.

Forty three percent of the labeled sites, at least, in the electroplax sodium channel with a photoactivable tetrodotoxin derivative were identified by probing protease-digested labeled fragments with several sequence-directed antibodies. They are located in the loop between segments S5 and S6 of domain IV, as well as the region containing transmembrane segment S6 and adjacent extracellular and cytoplasmic sequences in domain III. No photolabeled fragments were detected in the corresponding region of domain I. These results suggest that C-11 of tetrodotoxin where the photoreactive moiety is attached orients to the region between S5 and S6 in domain III and IV. Probable orientation of the tetrodotoxin molecule in sodium channels is considered by taking together with the recent report of the site-directed mutagenesis.

Amino Acid Sequence↗
PubMed1992

Interferon-gamma inhibits proliferation, but not commitment, of murine granulocyte-macrophage progenitors.

We investigated the effects of interferon gamma (IFN-gamma) on the growth of murine hematopoietic progenitors. IFN-gamma inhibited granulocyte colony-stimulating factor (G-CSF)- and interleukin-3 (IL-3)-dependent colony growth by granulocyte-macrophage (GM) progenitors derived from the bone marrow cells of normal mice. However, the number of IL-3-dependent GM colonies formed by the bone marrow cells of 5-fluorouracil (5-FU)-treated mice was not influenced by the addition of IFN-gamma. Replating experiments suggested that IFN-gamma suppressed GM colony growth directly and that it exerted an inhibitory effect on the proliferation, but not on the commitment, of GM progenitors. In contrast, IFN-gamma failed to suppress colony growth by mast cell progenitors. Erythroid and megakaryocytic progenitors exhibited different responses to IFN-gamma depending on mouse strains. These results suggest that potent negative regulators are not always inhibitors of hematopoietic progenitors.

Animals↗
PubMed1992

A phage in Bartonella bacilliformis.

Bacteriophage-like particles were found in Bartonella bacilliformis culture. The particles consisted of head (icosahedral), 40 nm in diameter, and tail, 16 nm in length.

Bacteriophages↗