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Biomedical subjects

H Kurata

Publications and source records attributed to H Kurata.

At least 91 records · Page 5Linked to original sources
PubMed1996

Synthesis and testosterone 5 alpha-reductase-inhibitory activity of 4-aza-5 alpha-androstane-17-carboxamide compound with an aromatic moiety in the C-17 carbamoyl group.

A series of 4-aza-5 alpha-androstane compounds with one or two aromatic moieties in the carbamoyl group at the C-17 position were synthesized and their inhibitory activities for rat and human prostatic testosterone 5 alpha-reductase were tested in vitro. Compounds with one aromatic moiety in the carbamoyl group showed high inhibitory activity for rat 5 alpha-reductase, but little for human prostatic 5 alpha-reductase. On the other hand, compounds with two aromatic moieties had potent inhibitory activities for both rat and human 5 alpha-reductase. The structural requirements for potent inhibition for both enzymes are discussed in relation to the spatial arrangement of the C-17 carbamoyl group.

5-alpha Reductase Inhibitors↗
PubMed1996

Rapid and sensitive screening of antifungal activity in medicinal plants by a single-cell biosensing system.

A biosensing system based on the response of fungal cells was used for the evaluation of antifungal activity of medicinal plants against Aspergillus niger. This system measured the hyphal growth rate in real time in the presence or absence of Chinese herbal extracts. The sensitivity of this system was 100-fold higher than that of conventional methods, and is advisable for the screening of antifungal compounds.

Antifungal Agents↗
PubMed1996

[Comparison between intermittent retrograde cold blood cardioplegia and retrograde crystalloid cardioplegia].

Intermittent retrograde cold blood cardioplegia was compared with retrograde crystalloid cardioplegia. Twenty-two adult patients underwent open heart surgery divided into two groups. Group BCP (n = 10) was protected with 15 degrees C blood containing potassium 15 mEq/l; Group CCP (n = 12) was protected with 4 degrees C St. Thomas' Hospital cardioplegic solution. Lactate, pyruvate, and CK-MB levels in coronary sinus blood were measured at 5 and 15 minutes after aortic unclamping and 5 minutes after weaning from cardiopulmonary bypass (CPB) in both groups. CPB time, cross-cross clamp time, incidence of postoperative low output syndrome and spontaneous return to sinus rhythm after aortic unclamping were not different between two groups. Cardiac index and pulmonary capillary wedge pressure measured immediately after weaning from CPB, were not different in both groups. Lactate level was significantly low in group BCP. Lactate uptaking ratio of myocardium was significantly high in group BCP. CK-MB levels were not different between two groups. Cold blood cardioplegia was seemed to provide better aerobic myocardial metabolism during aortic cross clamp. However, CK-MB levels and hemodynamic studies were not different.

Aged↗
PubMed1996

[Retrospective analysis on 21 patients with follicular lymphoma].

We retrospectively analyzed the clinical data of the 21 patients with follicular lymphoma admitted to our institution from 1977 to 1994. The frequency of follicular lymphoma was 9.1% in the 231 patients with non-Hodgkin's lymphoma. Overall survival rates at 1 year, 3 years, and 5 years were 90.2%, 78.2%, and 52.1%, respectively. The median follow-up of surviving patients and time to treatment failure (TTF) was 43 months and 30 months, respectively. The median time from disease progression to death was 171 days. In univariate analysis, factors associated with poor survival were stage IV (Ann Arbor staging system), anemia (hemoglobin level less than 10g/dl), bone marrow involvement, two or more extranodal sites, and failure in induction of complete remission (CR) in the entire course. Factors associated with short TTF were anemia, bone marrow involvement, and failure in induction of CR. In multivariate analysis, induction of CR affected survival and TTF independently.

Adult↗
PubMed1996

[Usefulness of magnetic resonance imaging in the determination of cervical involvement in endometrial cancer].

One hundred and sixty patients with FIGO stage I and II endometrial cancer entered this study. Magnetic Resonance Imaging (MRI; 61 cases), fractional curettage (110 cases) and hysteroscopy (119 cases) were performed to evaluate the presence of cervical involvement, and the findings were histologically compared with specimens obtained in abdominal hysterectomy. MRI showed the highest sensitivity (90.9%), specificity (96.0%) and diagnostic accuracy (95.1%) for the presence of cervical involvement. In 11 cases with cervical lesions, MRI predicted all 9 cases with invasion deeper than 1.5 mm. From these results we concluded that MRI appeared to be an excellent technique for cervical involvement and it would be a great help in determining the surgical procedure for endometrial cancer.

Endometrial Neoplasms↗
PubMed1995

Transmission of the effect of an antifungal agent within a single hypha.

A micro-compartment culture method was devised in which a single hypha of Rhizopus stolonifer growing on an agar section traversed an antifungal non-diffusible barrier to another agar section; thus the local environment of the distal or proximal part of the hypha could be controlled independently. The responses in terms of hyphal extension of the test fungus to local application of amphotericin B in this culture system were estimated by using an automatic analysing system. After hyphae had traversed the barrier, distal application of amphotericin B caused no appreciable effect on the proximal hyphae. In contrast, proximal application of amphotericin B caused inhibition of the extension of distal hyphae. The reversal of polarized cytoplasmic streaming also occurred during the inhibition of distal hyphal extension. The extents of inhibition of the distal hyphal extension and the cytoplasmic streaming were dependent upon the hyphal distance between the amphotericin B application site and the hyphal tip. These results show that the effect of an antifungal agent on a hypha depends on the region of the hypha exposed. Cytoplasmic streaming may play key role in the transmission of antifungal effects within a single hypha.

Amphotericin B↗
PubMed1995

Non-invasive method to detect motor unit contractile properties and conduction velocity in human vastus lateralis muscle.

The contractile properties and conduction velocity of motor units are estimated by using surface array electrodes during voluntary isometric contractions of the human vastus lateralis muscle. The subjects develop and maintain sufficient force to steadily discharge a given motor unit, assisted by visual feedback from an oscilloscope. The torque curve developed around the knee joint is triggered by an individual motor unit and averaged. 31 motor units in five subjects are studied. The twitch tension detected ranges from 3 to 27 m Nm with a mean of 12.3 m Nm. The threshold force ranges from 1.88 to 10.12 Nm with a mean of 5.48 Nm, which is 3% of the maximal voluntary contraction. The rise time ranges from 56 to 106 ms with a mean of 83 ms. The mean value of conduction velocity is 4.64 m s-1. The twitch tension is positively correlated to the threshold force (r = 0.839, p < 0.01), but has no relation to the other parameters. It is concluded that the use of non-invasive surface array electrodes provides the contractile properties of motor units and muscle fibre conduction velocity during weak contractions.

Electromyography↗
PubMed1995

Differential expression of granulocyte-macrophage colony-stimulating factor and IL-3 receptor subunits on human CD34+ cells and leukemic cell lines.

Cytokines transduce their signals through specific receptors. Receptors for granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-3, and IL-5 share the common signal transducing subunit (beta c), whereas the alpha subunits function as specific ligand binding components. In this study we prepared specific mouse monoclonal antibodies against human GM-CSF receptor-alpha subunit (hGMR alpha) by immunizing mice with Ba/F3 cells transfected with hGMR alpha complementary DNA. Using these anti-hGMR alpha antibodies in combination with antibodies against IL-3 receptor-alpha (IL-3R alpha), beta c subunits, and c-kit, we examined expression patterns and modulation of these receptor subunits on several human hematopoietic cells, including CD34+ cells and leukemic cell lines. GMR alpha and IL-3R alpha were expressed on GM-CSF- and IL-3-responsive cell lines, such as TF-1 and UT-7, whereas the expression levels were much lower on UT-7E, a GM-CSF- and IL-3-unresponsive subline of UT-7. The GMR alpha subunit was expressed only on mature granulocytes and monocytes, and IL-3R alpha was expressed on monocytes but not on mature granulocytes, and none of these subunits were expressed on lymphocytes. For CD34+ cells, GMR alpha was expressed more abundantly on CD34+ CD33high cells than on CD34+ CD33low cells, whereas IL-3R alpha was expressed more abundantly on CD34+ CD33low cells than on CD34+ CD33high and CD34+ CD33neg cells. Slight but significant expression of the beta c subunit was detected on CD34+ cells. Expression of not only GMR alpha and IL-3R alpha subunits but also c-kit was specifically downregulated by 48-hour incubation with their respective ligands. Receptor transmodulation between GM-CSF, IL-3, and stem cell factor (or kit ligand) was not detected on CD34+ cells in 48-hour cultures. We also detected upregulation of these alpha subunits by IL-1 alpha and interferon-gamma on leukemic cell lines. Our study showed expression levels for each receptor subunit--including GMR, IL-3R, and c-kit on human bone marrow and peripheral blood cells and leukemic cell lines--and revealed differential regulation of the expression of the receptor subunits.

3T3 Cells↗
PubMed1995

A human GM-CSF receptor expressed in transgenic mice stimulates proliferation and differentiation of hemopoietic progenitors to all lineages in response to human GM-CSF.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) mainly stimulates proliferation and maturation of myeloid progenitor cells. Although the signal transduction pathways triggered by GM-CSF receptor (GMR) have been extensively characterized, the roles of GMR signals in differentiation have remained to be elucidated. To examine the relationship between receptor expression and differentiation of hemopoietic cells, we used transgenic mice (Tg-mice) that constitutively express human (h) GMR at almost all stages of hemopoietic cell development. Proliferation and differentiation of hemopoietic progenitors in bone marrow cells from these Tg-mice were analyzed by methylcellulose colony formation assay. High affinity GMR interacts with GM-CSF in a species-specific manner, therefore one can analyze the effects of hGMR signals on differentiation of mouse hemopoietic progenitors using hGM-CSF. Although mouse (m) GM-CSF yielded only GM colonies, hGM-CSF supported various types of colonies including GM, eosinophil, mast cell, erythrocyte, megakaryocyte, blast cell, and mixed hemopoietic colonies. Thus, the effects of hGM-CSF on colony formation more closely resembled mIL-3 than those of mGM-CSF. In addition, hGM-CSF generated a much larger number of blast cell colonies and mixed cell colonies than did mIL-3. hGM-CSF also generated erythrocyte colonies in the absence of erythropoietin. Therefore, GM-CSF apparently has the capacity to promote growth of cells of almost all hemopoietic cell lineages, if functional hGMR is present.

Animals↗
PubMed1995

Ex vivo expansion of hematopoietic progenitor cells in human cord blood: an effect enhanced by cord blood serum.

The concept of ex vivo expansion of the human stem/progenitor cell population was tested in this study. Cord blood mononuclear cells were isolated and cultured in the presence of SCF, IL-3, and either cord blood serum (CBS) or fetal calf serum (FCS). After 8 days of incubation with CBS or FCS, the number of CFU-GM was increased ninefold and four-and-a-half-fold, respectively. However, the enhancing effect lasted for only a short period. This study demonstrates that CBS could contain growth factors expanding progenitor cells. Whether the ability of CBS to enhance the CFU-GM expanding capacity is attributable to a novel factor or factors, or represents effects of other known cytokines, remains to be determined.

Cell Differentiation↗
PubMed1995

[A surgical case of infective endocarditis accompanied with immune complex glomerulonephritis].

Infective endocarditis (IE) is often accompanied with renal disease. Recently it is thought that immune complex is formed by infecting agent of IE deposit to glomerulus and this contributes to glomerulonephritis. The case was 59-year-old man. He admitted with symptoms of proteinuria, hematuria and fever and diagnosed aortic regurgitation with vegetative change of aortic valve with echocardiogram. After admission he had stroke. Renal function was poor and circulating immune complex (CIC) value was high. Str. viridans was defined by blood culture examination. Aortic valve replacement was done because of no normalization of infective response and of renal function. Bacteria was not detected from the vegetation of valve but detected in the vegetation of transitional zone to mitral valve. Postoperative course was uneventful and renal function became normal with normalization of infective response. Anti C3d antibody value became normal and he discharged 50th postoperative day. In case of ineffective medical treatment the early removal of infected valve will make a successful result.

Aortic Valve↗
PubMed1995

[Is routine second-look operation justified for stage I ovarian cancer?].

The results and role of second-look operation (SLO) were evaluated in 33 patients with stage I epithelial ovarian cancer. 1. At SLO, histological evidence of disease was not identified in any of 24 patients, but washing cytology showed class III in 2 patients. 2. Only one (4.5%) patient with stage Ic (washing cytology: positive) has had a recurrence following negative SLO. 3. Recurrent tumor developed in 2 (33.3%) of the stage Ic (capsular invasion) patients and 1 (16.7%) of the stage Ic (washing cytology: positive) patient, but all patients with stage Ia or Ic (surgically ruptured by surgeon) are alive without recurrence. 4. Based on this experience, our current recommendation for patients with stage Ia or Ic (surgically ruptured by surgeon) epithelial ovarian cancer following comprehensive staging surgery and primary chemotherapy is that they do not require routine SLO.

Adenocarcinoma↗
PubMed1995

Intra-amniotic maternal hemorrhage in preterm labor: a case report.

A primigravid women was transferred to hospital because of preterm labor at 32 weeks' gestation with no vaginal bleeding. Hematologic studies showed severe anemia. Ultrasound examination revealed polyhydramnios and a clot around the umbilical cord without retroplacental hematoma. Diagnostic amniocentesis revealed heavily blood stained fluid, but HbF was not detected. With a clinical diagnosis of intra-amniotic maternal hemorrhage, immediate cesarean section was performed. The mechanism of intra-amniotic maternal hemorrhage is discussed.

Adult↗
PubMed1994

Structure and function of mannan-binding proteins isolated from human liver and serum.

Mannan-binding proteins (MBPs) occur in two forms, both of which are synthesized in the liver. Although two different MBP cDNAs have been cloned and characterized for rat and mouse, only one form of human MBP cDNA has been isolated. In this study, two forms of human MBP, liver MBP (L-MBP) and serum MBP (S-MBP), were purified from liver and serum and characterized, respectively. The amino acid sequences of these two human MBPs were identical and consistent with those deduced from the cDNA sequence. The most significant difference between L-MBP and S-MBP was the number of subunits, which was about 9 in L-MBP and 18 in S-MBP. Furthermore, S-MBP but not L-MBP had the ability to activate the complement. These results suggested that a newly synthesized protein is processed post-translationally into two forms, S-MBP and L-MBP, in human liver. Recombinant MBP synthesized in COS-1 cells, after transfection with human MBP cDNA, was secreted into the medium, suggesting that COS-1 cells lack a mechanism for differentiating S-MBP and L-MBP. A mutant MBP synthesized in COS-1 cells which lacked a sequence comprising 9 amino acid residues at the beginning of the collagen-like domain had no ability to activate the complement, suggesting that this sequence plays an important role in the activation of the complement by human MBP.

Amino Acid Sequence↗
PubMed1994

Adaptation of Aspergillus niger to several antifungal agents.

Adaptation of Aspergillus niger to short-term stress induced by three antifungal agents [amphotericin B (AMPH), miconazole (MCZ), and ketoconazole (KCZ)] was observed and evaluated quantitatively using individual hyphae. Spores were inoculated onto a poly-L-lysine-coated glass plate making up the base of a culture vessel. Potato dextrose broth (PDB) was added and the vessel incubated for 24 h at 28 degrees C. The growth rate of an arbitrarily selected test hypha was measured automatically. Exposure to AMPH (0.075 micrograms ml-1) stopped the growth of the hypha. After washing with PDB, the same concentration of AMPH was applied again. The growth of the test hypha was not inhibited. This phenomenon was defined as adaptation to the short-term stress of AMPH. Similarly, adaptation was observed with MCZ (0.01 microgram ml-1) and KCZ (0.5 microgram ml-1). The time required for the test hypha to restart growth after washing with PDB depended upon the concentration of MCZ or KCZ, but not upon the concentration of AMPH.

Adaptation, Physiological↗
PubMed1994

Non-insulin and non-exercise related increase of glucose utilization in rats and mice.

The effects of high-energy phosphate contents in muscles on glucose tolerance and glucose uptake into tissues were studied in rats and mice. Enhanced glucose tolerance associated with depleted high-energy phosphates and elevated glycogen content in muscles and liver was observed in animals fed creatine analogue beta-guanidinopropionic acid (beta-GPA). Distribution of infused 2-[1-14C]deoxy-D-glucose in tissues especially in the soleus muscle, kidney, and brain was greater in mice fed beta-GPA than controls. The glucose uptake was decreased when the contents of ATP and glycogen were normalized following creatine supplementation. Plasma insulin in animals at rest was lower and its concentration after intraperitoneal glucose infusion tended to be less in animals fed beta-GPA than controls (p > 0.05), although the pattern of insulin response to glucose loading was similar to the control. The daily voluntary activity in beta-GPA fed mice was also less than controls. These results suggest that improved glucose tolerance is not related to elevated insulin concentration and/or decreased glycogen following exercise. Such improvement may be due to an increased mitochondrial energy metabolism caused by depletion of high-energy phosphates.

Animals↗