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Biomedical subjects

K Okuda

Publications and source records attributed to K Okuda.

At least 289 records · Page 16Linked to original sources
PubMed1997

Cloning, expression, and sequencing of a protease gene from Bacteroides forsythus ATCC 43037 in Escherichia coli.

We have isolated and characterized an N-benzoyl-Val-Gly-Arg-p-nitroanilide-specific protease gene, designated prtH, from Bacteroides forsythus ATCC 43037. Nucleotide sequencing of the DNA insert from the clone (hereafter referred to as clone FST) revealed that the protease activity corresponded to an open reading frame consisting of 1,272 bp coding for a 47.8-kDa protein. When plasmid pFST was used as a probe in Southern hybridization, Sau3AI-digested chromosomal DNA of B. forsythus ATCC 43037 as well as the chromosomal DNAs of the isolated strains Ta4, TR5, and YG2 showed 0.6- and 0.8-kb hybridizing bands. The cell-free extracts of clone FST showed hemolytic activity on human blood cells. The hydrolytic activity of cell extracts of the pFST clone was inhibited by p-toluenesulfonyl-L-lysine chloromethyl ketone hydrochloride, leupeptin, N-ethylmaleimide, iodoacetic acid, iodoaceteamide, and EDTA.

Amino Acid Sequence↗
PubMed1997

Monophosphoryl lipid A enhances both humoral and cell-mediated immune responses to DNA vaccination against human immunodeficiency virus type 1.

To enhance immunity induced by DNA vaccination against human immunodeficiency virus type 1 (HIV-1), we evaluated the efficacy of monophosphoryl lipid A (MPL), an adjuvant of bacterial origin. BALB/c mice were intramuscularly injected with immunogenic DNA, encoding the env and rev genes of the HIV-1(IIIB) strain, formulated with MPL dissolved in different vehicles (MPL in stable emulsion and MPL in aqueous formulation). The sera from mice immunized with the two preparations of MPL revealed 2(6) to 2(9) times higher HIV-1-specific immunoglobulin G (IgG) titers than the sera from mice immunized without MPL. In virus neutralization tests for HIV-1(IIIB), by p24 assay and antifusion assay of infected MOLT-4 cells, MPL tends to elicit antibody more protective than antibody elicited without adjuvant. MPL also elicited stronger delayed-type hypersensitivity and cytotoxic-T-lymphocyte activity against HIV-1(IIIB) compared to DNA alone. HIV-1-specific IgG subclass analysis showed that MPL tends to facilitate IgG2a production, suggesting enhancement of a predominant T-helper-type-1 response, and this enhancement may help to facilitate protective-antibody induction. Furthermore, a chloramphenicol acetyltransferase (CAT) assay was employed to determine whether MPL affected the gene expression process. Interestingly, both MPL preparations reduced CAT activity in the muscle injected with CAT expression vector but increased anti-CAT antibody production. These results indicate that MPL acts as an effective adjuvant for immunogenic DNA injection despite reduced expression of encoding protein in muscle. We conclude that MPL has a strong adjuvant effect on DNA vaccination against HIV-1.

AIDS Vaccines↗
PubMed1997

Recognition of prominent viral epitopes induced by immunization with human immunodeficiency virus type 1 regulatory genes.

Mice immunized with the regulatory genes nef, rev, and tat from human immunodeficiency virus type 1 developed both humoral and cellular immune responses to the gene products Nef, Rev, and Tat. This study demonstrates that it is feasible to induce immune reactions to all of these regulatory gene products. Humoral responses were seen after DNA boosts, while potent T-cell proliferative responses were noted already after a single immunization. A Th1-directed immune response was demonstrated early after immunization. A 3- to 75-fold-stronger T-cell response was seen in animals receiving DNA epidermally compared to that in animals receiving intramuscular injections. Nef, Rev, and Tat putative B- and T-cell epitopes were clearly mapped by using peptides derived from the regulatory proteins and were similar to those which are detected in human immunodeficiency virus infection. Although immunization by the Nef, Rev, and Tat proteins raised high immunoglobulin G titers in serum, the epitope spreading appeared broader after DNA immunization. The combination of all of these regulatory genes together with two genes for structural proteins, the envelope and gag genes, demonstrated that a combined approach is feasible in that reactivities to all antigens persisted or were even augmented. No interference between plasmids was noted.

AIDS Vaccines↗
PubMed1997

The activity of 17alpha-hydroxylase/C17-C20 lyase in the ovaries of immature hypophysectomized rats treated with recombinant FSH combined with various doses of human chorionic gonadotropin.

The activity of 17alpha-hydroxylase/C17-C20 lyase (17alpha-hydroxylase) in the ovaries and steroid hormone levels in the plasma were studied in immature hypophysectomized rats (IH-rats) treated with human recombinant follicle-stimulating hormone (rec-FSH) alone or combined with various doses of human chorionic gonadotropin (hCG). Eleven days after hypophysectomy, rats were given rec-FSH alone (total dose, 40 IU), or combined with various doses (0.1 to 10 IU in total) of hCG, twice daily for 4 days. Plasma levels of progesterone, testosterone and estradiol, and ovarian 17alpha-hydroxylase activity were measured 18 h after the last injection. Histology showed that the ovaries treated with rec-FSH alone had large antral follicles, the theca interna cells of which were small in size compared with those treated with rec-FSH combined with hCG. The activity of 17alpha-hydroxylase in the ovaries of IH-rats treated with rec-FSH alone was lower than that in the control IH-rats. It was markedly increased by treatment with rec-FSH combined with 1 or 10 IU hCG. Immunohistochemistry revealed that 17alpha-hydroxylase was localized only in the oocyte in the ovaries of control IH-rats and those treated with rec-FSH alone. When the IH-rats were treated with rec-FSH plus hCG, the number of immunopositive theca interna cells and interstitial cells, and their immunointensity were increased in an hCG dose-dependent manner. The plasma estradiol levels in the IH-rats treated with rec-FSH alone were low, but significantly higher than those in the control IH-rats, and estradiol levels were noticeably elevated in IH-rats treated with rec-FSH plus hCG. These results suggest that a synergism between hCG (LH) and FSH is essential for follicular development and steroidogenesis in the ovaries, implying paracrine effects among granulosa cells, theca cells and probably oocytes. The functional significance of 17alpha-hydroxylase in the oocytes is discussed in relation to estradiol production.

Animals↗
PubMed1997

Vasodepressor effects of exercise are accompanied by reduced circulating ouabainlike immunoreactivity and normalization of nitric oxide synthesis.

Our object was to evaluate the effects of regular mild exercise on blood pressure and on circulating level of ouabainlike factors (OLF) and of nitrate anion, an endproduct of nitric oxide (NO) in humans. We measured plasma ouabainlike immunoreactivity (OLI) and nitrate ions (NO3.) before and after mild exercise for 3 months' duration in 16 patients with essential hypertension, diabetes mellitus, obesity, or hyperlipidemia. Plasma OLI was measured using an amplified ELISA system with anti-ouabain antibody and biotinyl-tyramide. Serum NO3. was measured with high-performance liquid chromatography (HPLC) with an anion-exchange column. With the reverse phase HPLC system with an octa decylsilyl silicagel column, the elution volume of plasma OLI of a healthy volunteer matched that of authentic ouabain in a gradient elution system of acetonitrile/H2O. Plasma OLI levels decreased significantly by about 34% after mild exercise, and NO3. levels tended to be within the reference interval in normal volunteers. Body weight, diastolic and systolic blood pressure, serum triglyceride and acetylcholine esterase (a marker of the fatty liver) were significantly decreased (p < 0.01) after 3 months of regular mild exercise. The plasma OLI level was significantly correlated with plasma NO3., there was a trend toward a correlation with diastolic blood pressure (p = 0.06) before and after regular exercise. Regular mild exercise led to a decrease in plasma levels of OLI, and acetylcholine esterase activity and blood pressure in adult patients. Results suggest that changes in OLF production contribute to the blood pressure regulation seen in patients who exercise regularly.

Adult↗
PubMed1997

[A case of isolated ACTH deficiency accompanied by generalized painful muscle cramp].

We report a patient who had generalized painful muscle cramps associated with isolated ACTH deficiency. A 68-year-old woman was hospitalized because of painful muscle cramps present for one year. Neurological examination revealed no abnormalities except for generalized painful muscle cramps. Serum electrolyte and CPK levels were normal. Serum ACTH and cortisol levels as well as urine 17-OHCS were low. An ACTH loading test employing insulin, TRH and LH-RH indicated isolated ACTH deficiency. Just after the muscle cramp, EMG revealed a low amplitude in the biceps muscle. Colon biopsy showed mild fibrosis and inflammatory cell infiltration in the lamina propria. Her muscle cramps improved markedly after two weeks of hydrocortisone replacement therapy and resolved after three weeks, suggesting that this symptom was closely related to isolated ACTH deficiency. Our case suggests that isolated ACTH deficiency may present with very similar clinical symptoms to Satoyoshi disease.

Adrenocorticotropic Hormone↗
PubMed1997

Intratumoral necrosis of lung carcinoma: a potential diagnostic pitfall in incremental dynamic computed tomography analysis of solitary pulmonary nodules?

The authors determined the pattern and enhancement range of necrotic lung carcinoma using incremental dynamic computed tomography (CT). Thirty-seven pathologically proven lung cancers (range, 8-57 mm in diameter) were evaluated using incremental dynamic CT. Scans were obtained before and 30 seconds, 2 minutes, and 5 minutes after the onset of contrast material injection. Computed tomography numbers in circular regions of interest (60% of tumor diameter) were calculated, and the difference in CT number between nonenhanced and the scan showing maximum attenuation was determined. In cavitary necrotic carcinomas, regions of interest were established excluding areas of cavitation. Nine (24%) of 37 lung carcinomas had intratumoral necrosis; four (11%) had noncavitary necrosis, and five (14%) had cavitary necrosis. Maximum attenuation of four noncavitary necrotic carcinomas (mean 31 +/- standard deviation 25 HU; range, -3-56 HU) was lower than cavitary necrotic carcinomas (42 +/- 8 HU; range, 35-51 HU; p = 0.36) and non-necrotic carcinomas (48 +/- 17 HU; range, 25-91 HU; p = 0.07). All carcinomas showed maximum attenuation > or = 25 HU except for one noncavitary necrotic carcinoma (maximum attenuation = -3 HU; 36 mm in diameter). Noncavitary necrosis was recognized as low attenuation on noncontrast scan in two of four cases and as an unenhanced area on enhanced scan in four of four cases. Although noncavitary necrotic lung carcinoma may rarely show maximum attenuation < or = 15 HU, necrotic material is recognized as unenhanced area on enhanced scan.

Aged↗
PubMed1997

[Continuous arterial infusion of low-dose cisplatin, 5-fluorouracil as adjuvant therapy in cytoreductive surgery for advanced hepatocellular carcinoma].

We investigated the effectiveness of continuous arterial infusion of low-dose CDDP, 5-FU for residual cancer after cytoreductive surgery for advanced hepatocellular carcinoma. Thirty-one patients with unresectable advanced hepatocellular carcinoma were classified into two groups by adjuvant therapy after reduction surgery: 1) Low-dose FP Group: 17 patients; continuous arterial infusion of low-dose CDDP, 5-FU via implanted port system; 2) Conventional group: 8 patients; Lipiodolization (6 cases) and transcatheter arterial embolization (2 cases). The five-year survival rate in the low-dose FP group was 34.8%, the efficacy was 64.7%, CR: 6 (35.3%); PR: 5; NC: 4; PD: 2. Thus, continuous arterial infusion of low-dose CDDP, 5-FU was effective as adjuvant therapy in cytoreductive surgery for advanced hepatocellular carcinoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Myocardial kinetics of iodine-123-BMIPP in canine myocardium after regional ischemia and reperfusion: implications for clinical SPECT.

UNLABELLED: To evaluate the clinical utility of 123I-(rho-iodophenyl)-3-R,S-methylpentadecanoic acid (123I-BMIPP) for ischemic heart disease, we investigated the metabolic fate of 123I-BMIPP in canine models with mild and severe ischemia and evaluated the clinical utility of this tracer. METHODS: Using open-chest dogs under anesthesia, we assembled a system that would release all the blood from the great cardiac vein without recirculation, if necessary. After injection of BMIPP into the left anterior descending coronary artery, blood samplings from cardiac vein and abdominal aorta were performed for 10-min ischemia (mild ischemia, five dogs) and 30-min ischemia (severe ischemia, six dogs), after reperfusion and for normal controls (six dogs). The catabolites of BMIPP, including backdiffusion of nonmetabolized BMIPP, were evaluated using high-performance liquid chromatography. RESULTS: Although the rapid extraction of BMIPP from the plasma into the myocardium and the subsequent retention were unchanged among three groups, the early washout (at 8 min) of radioactivity significantly increased (from 50% +/- 13% to 61% +/- 8%; p < 0.05) in severe ischemia. The metabolites from the myocardium consisted of backdiffusion of nonmetabolized BMIPP and alpha-oxidation, intermediate-oxidation and full-oxidation metabolites. For mild ischemia, these values were not significantly changed from the normal control, although the respective proportions of metabolites showed some variation. Lactate production after reperfusion on mild ischemia, which indicates the severity of ischemia, was closely correlated with the level of backdiffusion of BMIPP (r = -0.92) and the full-oxidation metabolite (r = 0.78). On the other hand, for severe ischemia, the level of backdiffusion of nonmetabolized BMIPP increased (from 25.1% +/- 8.0% to 34.7% +/- 8.7%; p < 0.05), and the full-oxidation metabolites decreased (from 21.4% +/- 10.9% to 14.8% +/- 7.3%). CONCLUSION: The metabolism of BMIPP was closely associated with the severity of myocardial ischemia. Thus, 123I-BMIPP might be a promising and sensitive radiopharmaceutical for the evaluation of ischemic heart disease.

Animals↗
PubMed1997

[Serum levels of tumor necrosis factor alpha and soluble tumor necrosis factor-receptor I in asthmatic patients and patients with chronic respiratory tract infection].

In order to investigate the role of tumor necrosis factor alpha (TNF-alpha) in bronchial asthma or chronic respiratory infection, we measured serum levels of TNF-alpha and serum soluble tumor necrosis factor-receptor I (sTNF-RI) in asthmatic patients (n = 11) and patients (n = 10) with chronic respiratory infection by Pseudomonas aeruginosa. We also measured serum levels of eosinophil cationic protein (ECP) in the asthmatic patients. The serum levels of TNF-alpha in the asthmatic patients, patients with chronic respiratory tract infection and control group were 2.864 +/- 0.719 g/ml, 2.564-1.384 pg/ml and 0.681 +/- 0.453 pg/ml respectively. The levels of the former two groups were higher than those of the control group (p < 0.05). The serum levels of sTNF-RI in the asthmatic patients, the patients with chronic respiratory tract infection, and the control group was 758 +/- 268 pg/ml, 999 +/- 242 pg/ml and 909 +/- 268 pg/ml respectively. The levels of the former two groups did not differ significantly from those of the control group. There were significant correlations between TNF-alpha and sTNF-RI in the control group and in the patients with chronic respiratory tract infection, but there was no significant correlation in the asthmatic patients. In the asthmatic patients. TNF-alpha/s TNF-RI correlated with %best of PEF (r = 0.691, n = 9, p 0.0373). The serum levels of ECP correlated significantly with TNF-alpha, but not with sTNF-RI in the asthmatic patients. It is suggested that TNF-alpha plays a significant role in the pathogenesis of bronchial asthma and chronic respiratory tract infection as a factor causing inflammation and that the increase of TNF-alpha/sTNF-RI reflects the activation of eosinophil functions in an asthmatic attack.

Adult↗
PubMed1997

[Effects of olprinone on IL-6 and IL-10 production during and after cardiac surgery].

Phosphodiesterase inhibitor (PDEI) has been accepted as an inodilator with positive inotoropic and vasodilating actions. Recently many new PDEIS have been available for the treatment of heart failure. We investigated the effect of a new PDEI-III agent, olprinone, on IL-6 and IL-10 production during and after coronary bypass graft surgery (CABG). Twelve patients scheduled for CABG were assigned to 2 groups. In 6 patients (Group-O), olprinone was administered continuously for 30 minutes at a rate of 0.3 micrograms.kg-1.min-1 (gamma) after the anesthesia induction. Then, the infusion rate of olprinone was decreased to 0.2 gamma and it was kept until the 3rd post-operative day. In another 6 patients (Group-C), phentolamine was used for vasodilator instead of olprinone. The plasma levels of IL-6 in Group-O did not show any significant change during perioperative period, whereas those in Group-C reached the peak at the end of extracorporeal circulation and did not recover to control level until the 3rd post-operative day. The plasma levels of IL-10 in Group-O increased to the maximum level at the end of extra-corporeal circulation and were significantly higher than those in Group-C. It is suggested that olprinone has not only inodilating action but also anti-inflammatory action at therapeutic concentrations used for heart failure.

Cardiac Surgical Procedures↗
PubMed1997

Bactericidal effects of mouth rinses on oral bacteria.

The bactericidal efficacy of two types of Listerine; Listerine and Cool Mint Listerine, and povidone iodine on oral microorganisms, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pyogenes, Helicobacter pylori and Candida albicans were examined. Most of the oral bacteria were killed completely by a 10-sec exposure to Listerine or Cool Mint Listerine. H. pylori, MRSA and C. albicans were also reduced by a 30-sec exposure to the Listerine mouth rinse. Bacteria in dental plaque were decreased by exposure to Listerine, Cool Mint Listerine, and povidone iodine for 30 seconds. Mouthwashing with Listerine for 30 seconds resulted in a decrease to approximately 1/100 of the viable bacterial counts in saliva. These bactericidal effects against bacteria in saliva and dental plaque indicated that Listerine and Cool Mint Listerine antiseptic are useful in oral cavity as antiseptic mouth rinses.

Adult↗
PubMed1997

[Efficacy and safety of sulbactam/cefoperazone for hepato-biliary infections].

We studied efficacy and safety of sulbactam/cefoperazone (SBT/CPT) in the treatment of biliary tract infections in hospitalized patients at 26 hospitals from February 1993 to March 1995. Secondary to dropout, 273 out of 338 patients entered in the study were evaluated, 127 patients with cholecystitis, 132 patients with cholangitis, and 14 patients with liver abscesses. Of these, 93 patients (34.1% had malignancy as an underlying disease. SBT/CPZ had an efficacy of 79.9% (218 patients; excellent: 52, good: 166), with the efficacy in patients with cholecystitis, cholangitis and liver abscess at 89.0% (113 patients), 77.3% (102 patients and 21.4% (3 patients), respectively. A significant difference (p < 0.05) was observed in the efficacy rates of patients with (59 patients [63.4%]) and without malignancy (159 patients [88.3%]). A total of 84 strains were isolated from bile specimens of 53 patients, and the major isolates were Escherichia coli, Pseudomonas aeruginosa and Enterococcus spp. Two or more bacterial strains were isolated simultaneously in 20 patients. Mild or moderate side effect (allergic reaction including rash etc.) were noted in 4 patients (1.18%), and laboratory abnormalities (increased GOT, etc.) were in 16 patients (4.71%) out of the total 338 patients. This study clearly demonstrated that SBT/CPZ retains its excellent clinical efficacy and safety profile, throughout its use over the past decade.

Adolescent↗
PubMed1996

Isolation and characterization of hemolytic genes from Actinobacillus actinomycetemcomitans.

Periodontopathic Actinobacillus actinomyceremcomitans produces hemolysin and other leukotoxins. In the present study, two distinct clones which lysed horse erythrocytes were isolated by screening genomic DNA libraries of A. actinomycetemcomitans ATCC 43718 on blood agar plates. DNA hybridization analysis indicates that there were two distinct hemolytic genes present. Sonicated extracts from both Escherichia coli clones possessed hemolytic activities on horse, sheep and human erythrocytes, but not those of rabbit. Rabbit antiserum to A. actinomycetemcomitans ATCC 43718 whole cells inhibited the hemolytic activities of these clones.

Aggregatibacter actinomycetemcomitans↗
PubMed1996

p210BCR/ABL, p190BCR/ABL, and TEL/ABL activate similar signal transduction pathways in hematopoietic cell lines.

The Philadelphia chromosome translocation generates a chimeric oncogene, BCR/ABL which causes chronic myelogenous leukemia. Two different fusion proteins can be produced, p190BCR/ABL and p210BCR/ABL, depending on the location of the breakpoint in BCR. Although the ABL tyrosine kinase activity of the resulting oncoprotein is essential for transformation, the exact functional contribution of BCR to transformation is unclear. A novel oncogene containing ABL is formed by the (9;12) translocation which fuses part of the ets-family member TEL to c-ABL in patients with acute leukemia. In an effort to compare the biological effects of various ABL oncogenes, we transformed two different factor-dependent murine hematopoietic cell lines with cDNA's encoding p210BCR/ABL, p190BCR/ABL, or TEL/ABL. Transfection of each of the three activated ABL oncogenes resulted in rapid emergence of growth factor-independence, and 2-4 sublines from each cell line with each oncogene were further studied. Each oncogene induced an increase in the tyrosine phosphorylation of cellular proteins and autophosphorylation of the oncoprotein itself. Overall, the pattern of increased tyrosine phosphorylation was similar in the cell lines, suggesting that many of the major substrates were identical. We specifically examined a series of proteins known to be p210BCR/ABL substrates, including rasGAP, Shc, SH-PTP2, SH-PTP1, CRK-L, CBL, paxillin, and STATs, and found that each were also tyrosine phosphorylated in response to p190BCR/ABL and TEL/ABL. These results suggest that the function of BCR can be largely replaced by the unrelated protein TEL with regards to transformation of murine hematopoietic cell lines to factor-independence, and support the hypothesis that a major contribution of both fusion partners is to activate the ABL tyrosine kinase.

Adaptor Proteins, Signal Transducing↗
PubMed1996

Purification and characterization of LasR as a DNA-binding protein.

In Pseudomonas aeruginosa, the activator protein LasR and a cognate autoinducer (AI) are required for expression of the elastase gene (lasB). In the present study, we investigated the binding properties of the P. aeruginosa lasR gene product. The LasR protein was overexpressed and purified as a glutathione S-transferase (GST) fusion protein. Using gel retardation and UV cross-linking analysis, we demonstrated that the GST-LasR could bind to a separate site in the lasB upstream operator regions 1 and 3 in the presence of the autoinducer. Regions 1 and 3 are located at 105 and 42 base pairs upstream, respectively, from the lasB transcriptional start site. Our present results clearly demonstrate that LasR is a specific DNA-binding protein that regulates the transcription of the lasB gene in the presence of an autoinducer.

4-Butyrolactone↗
PubMed1996

Infection with hepatitis GB virus C in patients on maintenance hemodialysis.

BACKGROUND: A recently discovered non-A-E hepatitis virus has been designated hepatitis GB virus C (HGBV-C), but little is known about its mode of transmission and its clinical manifestations. We studied 519 patients on maintenance hemodialysis to determine whether they were infected with HGBV-C. METHODS: HGBV-C RNA was identified in serum by a reverse-transcription-polymerase-chain-reaction assay with nested primers deduced from a non-structural region. A nucleotide sequence of 100 bp in the nonstructural region was determined on HGBV-C clones. RESULTS: HGBV-C RNA was detected on 3.1 percent of the patients on hemodialysis (16 of 519), as compared with 0.9 percent of healthy blood donors (4 of 448, P<0.03). None of the 16 patients had evidence of active liver disease, although 7 were also infected with hepatitis C virus. Eight patients with HGBV-C infection were followed for 7 to 16 years. In two patients the virus was present at the start of hemodialysis. One had a history of transfusion, and HGBV-C persisted over a period of 16 years; the other became free of HGBV-C after 10 years. In five patients, HGBV-C RNA was first detected 3 to 20 weeks after blood transfusion and persisted for up to 13 years. One patient with no history of transfusion was infected with an HGBV-C variant with the same sequence as in two of the patients with post-transfusion HGBV-C infections. CONCLUSIONS: Patients on maintenance hemodialysis are at increased risk for HGBV-C infection. This virus produces persistent infections, which may be transmitted by transfusions but may also be transmitted by other means.

Adult↗