Biomedical subjects

H Okano

Publications and source records attributed to H Okano.

At least 127 records · Page 7Linked to original sources

PubMed1998

Rhabdomyolysis and myocardial damage induced by palytoxin, a toxin of blue humphead parrotfish.

A 55-year-old man had rhabdomyolysis and myocardial damage induced by palytoxin. Weakness and myalgia of four extremities occurred five hours after eating a fish. Rhabdomyolysis developed and the serum creatine phosphokinase (CK) was elevated to 40,000 IU/l on the 3rd day. Gastric lavage with activated charcoal and forced mannitol-alkaline diuresis therapy were performed. The patient recovered with no complication such as renal failure. In this case, palytoxin was suggested to induce myocardial damage which was demonstrated by an elevation of the myosin light chain level and a change in electrocardiogram.

Acrylamides↗

PubMed1998

[Isoniazid-induced pneumonitis].

An 82-year-old man was treated with isoniazid (INH) because of a low-grade fever. On the 9th day of treatment, dry coughing and general malaise developed. On the 30th day, he was admitted to our hospital. A chest-X ray film showed infiltrative shadows in the right middle and lower lung fields, but a chest CT scan showed an abnormal lung density in the right lower lobe. Abnormal laboratory findings included leucocytosis, liver dysfunction, hypoxemia, low vital capacity, low diffusing capacity and a high level of C-reactive protein. A differential cell count of the bronchoalveolar lavage fluid (BALF) showed many neutrophils and lymphocytes; examination of a specimen obtained by transbronchial lung biopsy (TBLB) revealed edema of alveolar walls, lymphocyte infiltration, and proliferation of type II alveolar epithelial cells. A drug lymphocyte stimulation test (DLST) against INH was positive. After discontinuation of INH, symptoms resolved, laboratory findings became normal, and the infiltrative shadows in the right middle and lower lung fields disappeared. The clinical course and the findings of BALF, TBLB, and DLST suggested the diagnosis of pneumonitis caused by INH.

Aged↗

PubMed1997

Role of inositol 1,4,5-trisphosphate receptor in ventral signaling in Xenopus embryos.

The inositol 1,4,5-trisphosphate (IP3) receptor is a calcium ion channel involved in the release of free Ca2+ from intracellular stores. For analysis of the role of IP3-induced Ca2+ release (IICR) on patterning of the embryonic body, monoclonal antibodies that inhibit IICR were produced. Injection of these blocking antibodies into the ventral part of early Xenopus embryos induced modest dorsal differentiation. A close correlation between IICR blocking potencies and ectopic dorsal axis induction frequency suggests that an active IP3-Ca2+ signal may participate in the modulation of ventral differentiation.

Activins↗

PubMed1997

Expression of neural RNA-binding proteins in the postnatal CNS: implications of their roles in neuronal and glial cell development.

There is an increasing interest in the role of RNA-binding proteins during neural development. Mouse-Musashi-1 (m-Msi-1) is a mouse neural RNA-binding protein with sequence similarity to Drosophila musashi (d-msi), which is essential for neural development. m-Msi-1 is highly enriched in neural precursor cells that are capable of generating both neurons and glia during embryonic CNS development. The present study characterized m-Msi-1-expressing cells in the postnatal and adult CNS. Postnatally, m-Msi-1 was expressed in proliferative neuronal precursors in the external granule cell layer of the cerebellum and in the anterior corner of the subventricular zone of the lateral ventricles. In gliogenesis, the persistent expression of m-Msi-1 was observed in cells of the astrocyte lineage ranging from proliferative glial precursors in the subventricular zone (SVZ) to differentiated astrocytes in the parenchyma. In addition, we showed that m-Msi-1 was still expressed in proliferating cells in the adult SVZ, which may contain neural precursor or stem cells. Another neural RNA-binding protein Hu (the mammalian homolog of a Drosophila neuronal RNA-binding protein Elav) was present in postmitotic neurons throughout the development of the CNS, and its pattern of expression was compared with that of m-Msi-1. These observations imply that these two RNA-binding proteins may be involved in the development of neurons and glia by regulating gene expression at the post-transcriptional level.

Animals↗

PubMed1997

Structural properties and RNA-binding activities of two RNA recognition motifs of a mouse neural RNA-binding protein, mouse-Musashi-1.

mouse-Musashi-1 (m-Msi-1) is an RNA-binding protein, abundantly expressed in the developing mammalian central nervous system (CNS). m-Msi-1 contains two RNA recognition motifs (RRMs). In this study, we found that the N-terminal RRM of m-Msi-1 (MMA) binds strongly to poly(G) and weakly to poly(U) in a way similar to that of the full-length m-Msi-1 protein characterized previously. The C-terminal RRM of m-Msi-1 (MMB), however, does not bind to RNA. In addition, the circular dichroism (CD) spectra of the two RRMs showed that the alpha-helical content of MMA is significantly higher than that of MMB, indicating that some differences in the secondary structure may be responsible for the distinct RNA binding properties of MMA and MMB.

Amino Acid Sequence↗

PubMed1997

Developmental expression of the inositol 1,4,5-trisphosphate receptor and structural changes in the endoplasmic reticulum during oogenesis and meiotic maturation of Xenopus laevis.

To study the development of the calcium release mechanism, we examined the temporal and spatial expression of inositol 1,4,5-trisphosphate receptor (IP3R) during the oogenesis and meiotic maturation of Xenopus laevis. Observation of a series of fixed samples by immunofluoresence microscopy revealed a relocalization of Xenopus IP3R (XIP3R)-positive structures during meiotic maturation. We visualized the endoplasmic reticulum (ER) using ER-sensitive dye, DiI, by observation under confocal laser scanning microscopy. Time-lapse visualization of the living oocytes revealed that while the ER of immature fully grown oocytes underwent relatively little movement, the ER of maturing oocytes and mature eggs moved rapidly. A possible role for the increase of ER mobility in the dynamic redistribution of XIP3R during oocyte maturation is also discussed.

Animals↗

PubMed1997

Prevention of postmenopausal bone loss with minimal uterine bleeding using low dose continuous estrogen/progestin therapy: a 2-year prospective study.

OBJECTIVE: To re-examine the minimal effective dose of conjugated estrogen (CEE)-progestin hormone replacement on postmenopausal bone loss. DESIGN: A 2-year, prospective, open label, randomized study. SETTING: Department of Obstetrics and Gynecology of a university hospital. PARTICIPANTS: Fifty-two postmenopausal or oophorectomized women. INTERVENTION: One of the following regimens was continuously administered for 2 years: (1) CEE 0.625 mg/day, (2) CEE 0.625 mg + medroxyprogesterone (MPA) 2.5 mg/day, (3) CEE 0.31 mg + MPA 2.5 mg/day and (4) control. MEASUREMENTS: Lumbar spine and femoral BMD by dual energy X-ray absorptiometry (DXA), a monthly based incidence of bleeding, serum lipids, PTH, calcitonin. A1-p, and osteocalcin. RESULTS: Of the 52 patients enrolled in this study, 49 patients completed the 1 year of therapy and 36 completed the 2- year study. The control group showed a significant decrease in lumbar BMD over the 2 years (P < 0.05). The % changes in lumbar BMD at 2 years of CEE alone, CEE 0.625 + MPA and CEE 0.31 + MPA were 8.52% (95% confidence intervals; 4.61 approximately 12.4%), 7.4% (0.60 approximately 14.2%) and 3.20% (0.61 approximately 5.84%), respectively, and were significantly higher than pretreatment values. The incidence of bleeding was significantly lower in women taking CEE 0.31 mg + MPA. HDL cholesterol increased in women taking CEE 0.625 mg alone or with MPA. No significant changes in lipid profiles were seen in the control or in the group of women taking CEE 0.31 mg + MPA. CONCLUSIONS: Continuous hormone replacement therapy (HRT) using 0.31 mg of CEE and 2.5 mg of MPA is effective in increasing lumbar BMD in postmenopausal or oophorectomized women and can be an appropriate option for women with a normal lipid profile or those women wishing to eliminate unscheduled bleeding.

Bone Density↗

PubMed1997

Developmental expression of the inositol 1,4,5-trisphosphate receptor and localization of inositol 1,4,5-trisphosphate during early embryogenesis in Xenopus laevis.

To study the role of inositol 1,4,5-trisphosphate (IP3) receptors during early embryogenesis in Xenopus, we examined the temporal-spatial localization of Xenopus IP3 receptor (XIP3R). XIP3R protein is enriched in the animal hemisphere of early cleavage stage embryos and becomes localized in the ectoderm and involuted mesoderm in gastrula stage embryos. Up to tailbud stages, expression of XIP3R is observed in the mesodermal tissues and in most subregions of the central nervous system. A quantitative analysis of endogenous IP3 mass during normal early embryogenesis revealed an increase in IP3 mass first observed at early gastrula stage of 10.5 with an enrichment in the ectoderm throughout the gastrula stages, implying a potential role during gastrulation.

Animals↗

PubMed1997

Estrogen receptor gene polymorphism and bone mineral density at the lumbar spine of pre- and postmenopausal women.

In order to analyze the role of the estrogen receptor (ER) gene allelic polymorphisms on bone mineral density (BMD), 173 pre- and postmenopausal women were divided into four groups according to their menstrual status (group A: premenopausal women; group B: late premenopausal women; group C: postmenopausal women who had menopause for 5 years or less; and group D: postmenopausal women who had menopause for more than 5 years), and the relationship between ER gene polymorphism and lumbar spine BMD, the percent annual change in BMD and biochemical markers were studied. The restriction fragment length polymorphism (RFLPs) were represented as Xx (XbaI) and Pp (PvuII), with upper case and lower case letters signifying the absence or presence of restriction sites, respectively. In group A, the Xx genotype had significantly higher BMD (p < 0.01) than the xx genotype, but the difference was lost in groups B, C, and D. Because the percent annual change in BMD of group A was 0.052% and was not statistically different among genotypes, it is suggested that RFLP by Xba I is closely linked with peak bone mass that was attained during the subject's late thirties. In group B, serum N-region osteocalcin (N-OC) levels and the percent annual change in BMD showed a significantly larger increase than that of group A, indicating postmenopausal bone loss had commenced. Because the N-OC level of the Xx genotype was significantly higher than that of the xx genotype (p < 0.05), and the percent annual change in BMD of the Xx genotype showed a tendency to increase (p = 0.072), it is suggested that the high BMD of the Xx genotype is rapidly lost during menopausal transition. There were no significant relationships between RFLP and BMD in groups C and D, and between RFLP and BMD in groups C and D, and between RFLP by PvuII and BMD. The present study suggests that the Xx genotype is involved in accretion of BMD during young adulthood, but the effect was lost during menstrual transition.

Adult↗

PubMed1997

ICE/CED-3 family executes oligodendrocyte apoptosis by tumor necrosis factor.

Tumor necrosis factor (TNF) is thought to be one of the mediators responsible for the damage of oligodendrocytes (OLGs) in multiple sclerosis (MS). We report here the involvement of the interleukin 1beta-converting enzyme (ICE)/Caenorhabditis elegans gene ced-3 (CED-3) family in TNF-mediated cell death of OLGs. The addition of TNF-alpha to primary cultures of OLGs that express ice and cpp32 significantly decreased the number of live OLGs in 72 h. DNA fragmentation was detected in TNF-treated OLGs at 36 h with the terminal deoxynucleotidyl transferase dUTP nick end-labeling assay. Benzyloxycarbonyl-Asp-CH2OC(O)-2,6-dichlorobenzene, an inhibitor of the ICE/CED-3 family that shows p35-like inhibitory specificity, protected against the TNF-induced cell death of OLGs. Furthermore, acetyl-YVAD-CHO (a specific inhibitor of ICE-like proteases) as well as acetyl-DEVD-CHO (a specific inhibitor of CPP32-like proteases) enhanced the survival of OLGs treated with TNF-alpha, indicating that ICE- and the CPP32-mediated cell death pathways are activated in TNF-induced OLG cell death. Our results suggest that the inhibition of ICE/CED-3 proteases may be a novel approach to treat neurodegenerative diseases such as MS.

Animals↗

PubMed1997

Demonstration of an E-box and its CNS-related binding factors for transcriptional regulation of the mouse type 1 inositol 1,4,5-trisphosphate receptor gene.

The type 1 inositol 1,4,5-trisphosphate receptor (IP3R1) is expressed abundantly in the CNS, such as in cerebellar Purkinje cells and the hippocampus. We established a tissue-specific cell-free transcription system and studied regulatory properties of the 5' upstream region of the IP3R1 gene by use of this system. Deletion analyses of the promoter revealed several cis elements that function significantly in brain nuclear extracts. Among those elements, sequences from -398 to -295 showed the most predominant cerebellum-specific positive function. Footprint analyses demonstrated a factor-binding region from -334 to -318, termed box-I, that contained an E-box consensus sequence. Electrophoretic mobility shift assay revealed CNS-related basic helix-loop-helix proteins for the box-I. Mutational studies using the function assay and competitive electrophoretic mobility shift assays demonstrated a good correlation between the box-I-binding factors and the activated transcription. Box-I-binding factors were present abundantly in adult mouse CNS, whereas their existence was restricted in embryonic and nonneural tissues. Transient chloramphenicol acetyltransferase assay for the IP3R1 promoter revealed the requirement of box-I in Neuro2a neuroblastoma cells. In the postnatal CNS, multiple basic helix-loop-helix factors are expressed abundantly, some of which are suggested to activate IP3R1 gene expression in the mammalian CNS.

Animals↗

PubMed1997

Efficacy of toki-shigyakuka-gosyuyu-syokyo-to (danggui-sini-jia-wuzhuyu-shengjiang-tang) on peripheral circulation in autonomic disorders.

To investigate the improvement in peripheral circulation in autonomic disorders, we monitored skin temperature in the tails of rats by thermography before and after the oral administration of boiled water extract of Toki-shigyakuka-gosyuyu-syokyo-to (TSGS-to). Oral administration of this extract elevated the temperature, calculated as the calories of radiant heat in the rat tail 5-10 min after uptake. The temperature elevation remained stable for more than 20 min. Calories were significantly reduced 60 min after uptake and almost returned to initial values 90 min later. Some of the constituent herbs, especially Angelicae radix, Cinnamomi cortex, Evodiae fructus, and Zingiberis rhizoma, appeared to be active in relieving hypothermia.

Administration, Oral↗

PubMed1997

Intrinsic and extrinsic determinants regulating cell fate decision in developing nervous system.

Cell fate in the nervous system is determined by environmental signals and/or heredity. They can be referred to as extrinsic and intrinsic determinants, respectively. The molecular and cellular mechanisms underlying these processes are well conserved from invertebrates to vertebrates. We have identified both types of determinants through the intensive screening of P-element-induced Drosophila mutants affected in neural development. As a member of the first category, argos gene product which regulates cell-cell interaction in the developing nervous system gives a good example. As a member of the second category, we refer to Drosophila musashi gene encoding a neural RNA-binding protein. The fractions of these gene products and application to the mammalian nervous system will be discussed.

Animals↗

PubMed1997

Two-step induction of chordotonal organ precursors in Drosophila embryogenesis.

The chordotonal (Ch) organ, an internal stretch receptor located in the subepidermal layer, is one of the major sensory organs in the peripheral nervous system of Drosophila melanogaster. Although the cell lineage of the Ch organ has been well characterized in many studies, the determination machinery of Ch organ precursor cells (COPs) remains largely unresolved. Here we report that the rhomboid (rho) gene and the activity of the Drosophila EGF receptor (DER) signaling pathway are necessary to induce specifically three of the eight COPs in an embryonic abdominal hemisegment. The cell-lineage analysis of COPs using the yeast flpase (flp/FRT) method indicated that each of the eight COPs originated from an individual undifferentiated ectodermal cell. The eight COPs in each abdominal hemisegment seemed to be determined by a two-phase induction: first, five COPs are determined by the action of the proneural gene atonal and neurogenic genes. Subsequently, these five COPs start to express the rho gene, and rho activates the DER-signaling pathway in neighboring cells and induces argos expression. Three of these argos-expressing cells differentiate into the three remaining COPs and they prevent neighboring cells from becoming extra COPs.

Animals↗

PubMed1997

[Massive hemoptysis in a patient with a tuberculous thoracic aneurysm].

A 91-year-old man with a history of pulmonary tuberculosis 20 years earlier came to our hospital because of hemoptysis in May 1993. A chest X-ray film showed infiltrative shadows in the left first arch of the cardiac silhouette, and sputum cultures were positive for Mycobacterium tuberculosis. Despite treatment with antituberculosis drugs, chest X-ray films revealed gradual progression, and he had occasional hemoptysis. He was admitted because of massive hemoptysis in December 1993 and a computed tomogram of the chest revealed an aneurysm of the descending aorta. Sudden and massive hemoptysis occurred in January 1994. At autopsy, the wall of the aneurysm and the surrounding tissue were found to have histological changes characteristic of tuberculosis. Tuberculous thoracic aneurysms are quite rare, but may develop in patients with tuberculosis in other areas.

Aged↗

PubMed1997

[Relationship between the activity of serum adenosine deaminase including its isozymes and lymphocyte subpopulation in patients with pulmonary tuberculosis].

Adenosine deaminase (ADA) is one of the enzymes in the purine metabolism and divided into two isozymes, ADA-1 and ADA-2. It is known that the activity of this enzyme is elevated in the sera of patients with pulmonary tuberculosis, sarcoidosis and other diseases, however there are few reports about the change of the activity of this enzyme under treatment. It is often said that this enzyme may have its origin in T lymphocyte, but it remains to be proved. That goes for each of two isozymes, too. In this study, we investigated the activity of serum total ADA, ADA-1 and ADA-2 in patients with pulmonary tuberculosis on admission and after three months' treatment. We also studied the correlation of lymphocyte subpopulation with these enzymes. The activity of total ADA, ADA-1 and ADA-2 was significantly higher in the sera of patients with pulmonary tuberculosis than in those of healthy persons. ADA-2 activity correlated significantly and negatively with the number of CD3+ lymphocytes and CD4+ lymphocytes. The change rate of ADA-2 activity during three months' treatment correlated significantly and negatively with the change rate of CD4/8. These results may suggest that there is a close correlation between the activity of ADA-2 and lymphocyte subpopulation in the sera of patients with pulmonary tuberculosis. ADA-1 activity did not correlate with lymphocyte subpopulation significantly, but it decreased significantly after three months' treatment. The activity of ADA-1 also may have certain relations with the disease process of pulmonary tuberculosis.

Adenosine Deaminase↗

PubMed1997

[Etoposide-induced pneumonitis].

A 70-year-old man was given a diagnosis of small cell lung cancer because of the findings of examination of a specimen obtained by transbronchial lung biopsy from the rS4 a. He was treated with 2 courses of neoadjuvant chemotherapy (CBDCA, Etoposide) and underwent right middle lobectomy. He was then given 3 courses of adjuvant chemotherapy (CBDCA, Etoposide) as an inpatient and received oral etoposide (50 mg/day) as an outpatient. He was then admitted to our hospital because of dyspnea and fever. A chest-X-ray film showed reticulonodular shadows in both lung fields and blood gas analysis showed marked hypoxemia. A differential cell count of bronchoalveolar lavage fluid showed a high level of lymphocytes; and examination of a specimen obtained by transbronchial lung biopsy revealed edema of the alveolar walls, lymphocyte infiltration, and marked proliferation of type II alveolar epithelial cells. Administration of etoposide was stopped and steroid therapy was given. The symptoms, hypoxemia, and bilateral reticulonodular shadows resolved. The clinical course along with the findings from examination of bronchoalveolar lavage fluid and of the biopsy specimen, suggest that this patient had drug pneumonitis caused by oral etoposide.

Administration, Oral↗

PubMed1997

[Mycoplasma pneumoniae pneumonia with diffuse nodular shadows and right hilar lymphadenopathy].

A 51-year-old man was admitted to our hospital because of fever, a productive cough, and dyspnea. His chest X-ray film revealed diffuse reticulonodular shadows and right hilar lymphadenopathy. A chest CT scan revealed thickened bronchial walls and diffuse centriacinar or centrilobular nodular shadows. Serologic testing provided conclusive evidence of Mycoplasma pneumoniae infection. The diffuse pattern and hilar lymphadenopathy on chest X-ray films are uncommon in this disease, and they caused some uncertainty regarding the correct diagnosis. M. pneumoniae attaches to cells of the respiratory tract and produces a locally acting cytotoxin. Immunologic mechanisms have been shown to play an important role in the pathogenesis of pneumonia. This case suggests that immunologic mechanisms are an important factor in diffuse lung lesions.

Humans↗