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Biomedical subjects

K Sano

Publications and source records attributed to K Sano.

At least 91 records · Page 5Linked to original sources
PubMed2000

Contribution of endogenous nitric oxide to basal vasomotor tone of peripheral vessels and plasma B-type natriuretic peptide levels in patients with congestive heart failure.

OBJECTIVES: We examined whether a relationship exists between the vasoconstrictive response to endogenous nitric oxide (NO) synthesis inhibition and the severity of heart failure in patients with congestive heart failure (CHF). BACKGROUND: Controversy exists as to whether the vasoconstrictive response to NO synthesis inhibition in patients with CHF is comparable to that in normal subjects or is enhanced. METHODS: Forearm blood flow (FBF) and calculated forearm vascular conductance (FVC) were obtained using plethysmography before and after administration of the NO synthesis inhibitor L-NMMA (NG-monomethyl-L-arginine) in 40 patients with CHF due to dilated cardiomyopathy and in 16 normal control subjects. Basal plasma B-type natriuretic peptide (BNP) and nitric oxide concentrations were measured in all subjects. RESULTS: Plasma BNP and nitrite/nitrate (NOx) levels in the patients group were significantly greater and baseline FBF was significantly less. Administration of L-NMMA significantly decreased FBF and FVC in both groups. The percent changes in FBF (%FBF) and FVC (%FVC) from the baseline after L-NMMA correlated significantly with plasma BNP level (%FBF: r = 0.72; %FVC: r = 0.76; both p < 0.001). Percent changes in both FBF and FVC were greater in patients with BNP > or = 100 pg/ml than in normal subjects; however, in patients with BNP < 100 pg/ml they were comparable to those in normal subjects. CONCLUSIONS: Vasoconstrictive response to L-NMMA in patients with CHF was preserved or enhanced in proportion to the basal plasma BNP level, indicating a close relationship between the contribution of endogenous NO to basal vasomotor tone and the severity of heart failure.

Adult↗
PubMed2000

Acute megakaryoblastic leukemia in an infant with a novel t(1;9)(p32;q34).

We report a case of a 14-month-old girl with acute megakaryoblastic leukemia (AMKL). May-Giemsa staining of the bone marrow cells revealed the proliferation of two distinct types of blasts. One type of blasts had cytoplasmic blebs, and the other showed a lymphoblastic morphology without blebs. Both types of blasts were negative for peroxidase and esterase reactions. Electron microscopic platelet peroxidase (PPO) reaction also revealed the presence of two types of blasts. One had irregular-shaped nuclei and positive PPO reaction in the nuclear envelope and rough endoplasmic reticulum but not in the Golgi apparatus. These types of blasts were considered to be megakaryoblasts. The other had an immature phenotype with round nuclei and positive PPO reaction in the nuclear envelope, rough endoplasmic reticulum, and the Golgi apparatus. The origin of this type of blasts could not be defined by their morphology. Surface marker analysis indicated that most of the leukemic cells expressed platelet markers, gpIIb, gpIIb/IIIa, gpIX, and gpIbalpha. Karyotypic analysis of the bone marrow cells of this unique subset of AMKL demonstrated a novel translocation, t(1;9)(p32;q34).

Blood Platelets↗
PubMed2000

In vitro processing of human immunodeficiency virus type 1 Gag virus-like particles.

Human immunodeficiency virus (HIV) Gag proteins are assembled into virus particles and then cleaved by the virion-associated HIV protease. Concomitant with Gag processing, doughnut-like HIV particles (the immature form) are converted to particles containing condensed cores (the mature form). Here we describe the in vitro processing of immature HIV Gag virus-like particles (VLP) by exogenously added HIV protease. Following delipidization, sequential processing of immature VLP showed that the matrix (MA)/capsid (CA) junction was cleaved faster than the CA/nucleocapsid (NC) junction, an altered order of processing when compared with authentic processing. When the in vitro processed VLP were analyzed on density gradients, most of the MA, CA-p15 intermediate, and NC were detected as a highly multimeric form, equivalent to the unprocessed VLP. In contrast, CA was found as a monomer dissociated from the multimeric CA-p15 following cleavage of the CA/NC junction. Electron microscopy revealed that the in vitro processing was accompanied by conversion of the doughnut-like particles to particles containing condensed cores and spherical outer shells. The cores, however, lacked core shells, which are normally observed for authentic HIV, suggesting that the in vitro processing of immature VLP failed to produce core shells.

Animals↗
PubMed2000

'Double-Drugs'--a new class of prodrug form of an HIV protease inhibitor conjugated with a reverse transcriptase inhibitor by a spontaneously cleavable linker.

We designed and synthesized a new series of prodrug-type anti-HIV agents consisting of a peptidomimetic HIV protease inhibitor conjugated with a nucleoside reverse transcriptase inhibitor in an effort to enhance the antiviral activity. For the conjugation, a series of linkers that conjoin the two different classes of inhibitors have been investigated. Conjugates using a succinyl amino acid linker were shown to release the parent components via the spontaneous imide formation at a faster rate compared to conjugates using a glutaryl amino acid linker, as expected from the energetically favorable cyclization to the five-membered ring. Herein, we report a new 'double-drug' 4b (KNI-1039) with a glutarylglycine linker, which exhibited extremely potent anti-HIV activity compared with that of the individual components.

Anti-HIV Agents↗
PubMed2000

Regulation of murine airway eosinophilia and Th2 cells by antigen-conjugated CpG oligodeoxynucleotides as a novel antigen-specific immunomodulator.

The characteristic features of bronchial asthma reflect the orchestrated activity of Th2 cells. Oligodeoxynucleotides containing CpG motifs (CpG) have recently been highlighted as an immunomodulator that biases toward a Th1-dominant phenotype. We have previously reported that intratracheal coadministration of CpG and allergen inhibited airway eosinophilia and hyperresponsiveness in a synergistic manner. To substantiate the synergism between CpG and Ag, we introduced a covalently linked conjugate between CpG and Ag and examined the efficacy on airway eosinophilia and Th2 cytokine production. We found that the conjugated form of CpG plus Ag was 100-fold more efficient in regulating airway eosinophilia than the unconjugated mixture. The inhibitory effects lasted for at least 2 mo. The inhibition of airway eosinophilia by the conjugate was Ag specific and associated with an improvement of the airway hyperresponsiveness and the unresponsiveness of the Ag-specific Th2 cells in the regional lymph nodes. The CpG-Ag conjugate was 100-fold more effective than the unconjugated mixture for inducing in vitro Th1 differentiation in an IL-12-dependent manner. Our data show that CpG conjugated to Ag can work as a novel Ag-specific immunomodulator and imply that inhalation of allergen-CpG conjugate could be a desensitization therapy for patients with bronchial asthma.

Adjuvants, Immunologic↗
PubMed2000

Left hemihepatectomy in living donors with a thick middle hepatic vein draining the caudal half of the right liver.

Donor safety is the first consideration in living related liver transplantation. Left hemihepatectomy including the middle hepatic vein is a reasonable donor procedure for obtaining a large graft for living related liver transplantation. This procedure, however, needs to be modified in donors with hepatic venous variation. While carrying out donor hepatectomy, we encountered two cases showing a variant form of hepatic venous drainage comprising a thick middle hepatic vein draining segment 6 of the liver. This variation made it necessary to preserve the middle hepatic vein in the donor liver remnant. Failure to recognize such a variant would result in congestion in the remaining right liver of the donor. To guarantee donor safety, evaluation of the drainage area of the corresponding hepatic vein is a matter of great importance in donor hepatectomy.

Adolescent↗
PubMed2000

The effects of midazolam and flumazenil on psychomotor function and alertness in human volunteers.

OBJECTIVE: To investigate the effect of midazolam and flumazenil on psychomotor function and alertness in human volunteers. DESIGN: Randomised, double-blind, cross over study. METHODS: Intravenous flumazenil was administered to sedated and non-sedated healthy human volunteers, in doses typical of those used clinically to induce sedation with midazolam and for reversal with flumazenil. Subjective assessment of alertness and objective measures of psychomotor function using light reaction time and the Maddox wing were made over a 1 hour period. RESULTS: Seven males and seven females each attended four experimental sessions. Psychomotor function was impaired by midazolam but there was some individual variation to this response. All sedated subjects receiving flumazenil had significantly improved alertness and psychomotor function when compared with those subjects who received placebo. Mean alertness (P < 0.01) and light reaction time (P < 0.05) showed significant improvement and returned to baseline by 60 minutes. Stability also showed significant improvement (P < 0.05) but did not return to baseline by 60 minutes. There was no significant effect on psychomotor function or alertness when the antagonist flumazenil was administered in the absence of the agonist midazolam. CONCLUSION: An earlier discharge time based on subjective assessment of alertness is not advocated for patients whose intravenous midazolam sedation is reversed with flumazenil.

Adult↗
PubMed2000

Novel SH3 protein encoded by the AF3p21 gene is fused to the mixed lineage leukemia protein in a therapy-related leukemia with t(3;11) (p21;q23).

The mixed lineage leukemia (MLL) gene located at chromosome band 11q23 is frequently rearranged in patients with therapy-related acute monocytic leukemia who received topoisomerase II inhibitors. We have identified a novel fusion partner of MLL (FAB M5b) in a patient who developed t-AML 9 years after treatment for acute lymphoblastic leukemia (ALL). The leukemic cells had a sole karyotypic abnormality of t(3;11) (p21;q23). Screening of a genomic DNA library, prepared from leukemic cell DNA, identified rearranged clones composed of MLL and a novel gene on chromosome 3p21 (AF3p21). The AF3p21 gene encodes a protein of 722 amino acids, which contains an Src homology 3 (SH3) domain, a proline-rich domain, and a bipartite nuclear localizing signal (NLS). RNA analysis demonstrated that exon 6 of the MLL gene fused to exon 2 of the AF3p21 gene. The resulting chimeric protein consists of AT-hooks, methyltransferase, and transcription repressor domains of MLL in addition to the AF3p21 proline-rich domain and NLS but not the AF3p21 SH3 domain.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Randomized trial of the usefulness of a bile leakage test during hepatic resection.

HYPOTHESIS: An intraoperative bile leakage test will assist in decreasing postoperative bile leakage in patients undergoing hepatic resection. DESIGN: Randomized controlled trial. SETTING: University hospital. PATIENTS: One hundred three consecutive patients who were scheduled for hepatic resection without biliary reconstruction. Associated cirrhosis was present in 49 patients (48%), and only 24 (23%) had normal livers. Patients were randomized to undergo (n = 51) or to not undergo (n = 52) a bile leakage test, according to age, liver function, and hepatectomy method. The 2 groups were similar in baseline demographics. INTERVENTION: A bile leakage test was carried out by injecting isotonic sodium chloride solution through the cystic duct, and interrupted suturing was taken for a bile leak on the transected liver surface. MAIN OUTCOME MEASURES: The incidence of postoperative bile leakage and the length of the postoperative hospital stay. Bile leakage was defined as continuous drainage, with a bilirubin level of 86 micromol/L or more (> or =5 mg/dL), beyond 1 week. RESULTS: Twenty-one patients (41%) in the test group showed a bile leak, and a median of 1 site (range, 1-6 sites) was closed during the test. Postoperative bile leakage was observed in 3 patients (6%) in the test group and in 2 (4%) in the control group (P = .99). The odds ratio of the event was 1.53 (95% confidence interval, 0.25-9.44). The median postoperative hospital stay lasted 17 (range, 13-47) and 18 (range, 12-41) days for the test and control groups, respectively (P =.98). CONCLUSION: This randomized trial suggested no advantage in using a bile leakage test during hepatic resection.

Adult↗
PubMed2000

Enhanced cell death in NR-S1 tumor by photodynamic therapy: possible involvement of Fas and Fas ligand system.

BACKGROUND AND OBJECTIVES: To investigate the effect of photodynamic therapy (PDT) on cell death in malignant tumor tissue, the frequency of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells and the possible involvement of Fas and Fas ligand system were evaluated. STUDY DESIGN/MATERIALS AND METHODS: NR-S1 tumor-bearing C3H/HeNCrj mice were treated by PDT with Photofrin(R) (12 mg/kg body weight) and Nd:YAG dye laser (630 nm, 10 Hz, 150 J/cm(2)). Paraffin-embedded tissue sections from the excised tumor tissues at 6, 12, 24, 48 hours after PDT were analyzed by TUNEL for the occurrence of apoptosis and by immunohistochemistry for Fas and Fas ligand (FasL) expression. TUNEL-positive cells as well as Fas- or FasL-positive cells were counted and expressed as a percentage of positive cells per total cells. RESULTS: Based on the percent area of tumor necrotic foci, the most effective conditions for PDT were first determined. Under these conditions, PDT increased the number of TUNEL-positive tumor cells at 12 hours after irradiation. In parallel with the increase in TUNEL-positive cells, Fas-positive tumor cells were also found in the same area where many TUNEL-positive tumor cells were found. The expression of Fas ligand was found in the tumor cells surrounding TUNEL-positive cells on serial sections. A significant increase in FasL-positive lymphocytes was observed at 12 hours, whereas the infiltration of such lymphocytes into the area where TUNEL-positive tumor cells were observed was rare. CONCLUSION: The possible role of Fas/FasL system in the cell death induced by PDT with Photofrin(R) and Nd:YAG dye laser was suggested. Moreover, the role of infiltrated lymphocytes seemed not to be so much in this model.

Animals↗
PubMed2000

Enhancement of the photodynamic antitumor effect by streptococcal preparation OK-432 in the mouse carcinoma.

Biological response modifier antitumor effects are enhanced by the activation of the host defense mechanisms. We have investigated the antitumor effect of photodynamic therapy (PDT) and/or local administration of a biological response modifier, the streptococcal preparation OK-432, on transplanted NR-S1 mouse squamous cell carcinoma. Hematoporphyrin oligomers (20 mg/kg body weight) were used to photosensitize PDT. A pulsed Nd:YAG dye laser, tuned at 630 nm, was used as the light source. The laser power was 15 mJ cm(-2) pulse(-1), and the irradiation time was 40 min. The photosensitizer was injected intraperitoneally 48 h before laser irradiation. Where used, OK-432 was injected into the tumor either 3 h prior to PDT or immediately afterwards. The antitumor effects were evaluated 48 h after each protocol by (a) estimating the area of tumor necrosis (%) in hematoxylin/eosin-stained specimens, and (b) bromodeoxyuridine immunohistochemistry. Furthermore, the tumor sizes were evaluated 3, 7 and 10 days after each protocol, and the survival time after each protocol was evaluated as well. The antitumor effect of PDT was enhanced by administration of OK-432 3 h before PDT, whereas the administration of OK-432 immediately after PDT did not potentiate a PDT antitumor effect. Treatment with OK-432 alone had little effect on tumors. Photodynamic therapy in combination with local administration of OK-432 3 h before PDT is considered to be a useful treatment modality.

Animals↗
PubMed2000

Expression of lung resistance protein in epithelioid sarcoma in vitro and in vivo.

The incidence of epithelioid sarcoma among patients with malignant soft tissue tumors is small, but the rates of recurrence and metastasis of this type of sarcoma are high. To date, effective chemotherapy for advanced epithelioid sarcoma has not been established and, furthermore, epithelioid sarcoma is known to exhibit multidrug resistance (MDR). The chemosensitivities to anticancer agents of two cell lines established from epithelioid sarcoma were examined in this study. The results showed that the ES-OMC-MN and SFT-8606 cell lines were resistant to vincristine (IC50 1190 nM and 872 nM, respectively) and Adriamycin (IC50 921 nM and 650 nM, respectively), but sensitive to actinomycin D (IC50 < 10 nM). P-glycoprotein (p-Gp) and MDR-associated protein (MRP) were not expressed in these cell lines, but a high expression level of lung resistance protein (LRP) was observed. The original tumor tissues from which the two cell lines were established were also found to be LRP-positive but not to express p-Gp or MRP. Their chemosensitivities to Adriamycin were not significantly altered in the presence of 2.5 microg/ml anti-LRP antibody (LRP-56), but the IC50 of vincristine was much less (IC50 128 nM and 27 nM, respectively) than that for an untreated cell line. It is thus suggested that the vincristine resistance in the two cell lines is LRP-mediated. Since cyclosporin A, known to be a modifier of p-Gp, also induced reversal of vincristine resistance in the ES-OMC-MN and SFT-8606 cell lines (IC50 6.2 nM and 17 nM, respectively), it is suggested that cyclosporin A acts as a modifier of MDR mediated by LRP.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed2000

Characterization of the gammac chain among 27 unrelated Japanese patients with X-linked severe combined immunodeficiency (X-SCID).

X-linked severe combined immunodeficiency (X-SCID) is a rare fatal disease that is caused by mutations in the gene encoding the gammac chain. In this study, 27 unrelated Japanese patients with X-SCID were examined in terms of their genetic mutations and surface expression of the gammac chain. Among 25 patients examined, excluding two patients with large deletions, 23 different mutations were identified in the IL2RG gene, including 10 novel mutations. One patient bearing an extracellular mutation and all three of the patients bearing intracellular mutations after exon 7 expressed the gammac chain on the cell surface. Overall, 84% of patients lacked surface expression of the gammac chain leading to a diagnosis of X-SCID.

Antibodies, Monoclonal↗
PubMed2000

Anatomical keys and pitfalls in living donor liver transplantation.

The surgery of living donor liver transplantation is more technically challenging than cadaveric whole liver transplantation and liver resection for the treatment of various pathological conditions. It requires a thorough understanding of the intra- and extra-hepatic anatomical relationships between the portal vein, hepatic artery, biliary tract, and hepatic vein, and also their respective contributions to liver physiology. Although a precise understanding of general anatomical principles is the key to correctly performing living donor liver transplantation procedures, anatomic anomalies are often present, and the means of detecting them and the surgical methods of coping with them represent technical challenges. In this monograph, we describe the anatomical keys and pitfalls of living donor liver transplantation surgery based on our own experience with more than 1800 hepatectomies, and 150 living donor liver transplantations. We also elaborate on techniques of selective intermittent vascular occlusion and their teleological and practical background.

Bile Ducts↗