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Biomedical subjects

K Okuda

Publications and source records attributed to K Okuda.

At least 235 records · Page 13Linked to original sources
PubMed1998

Alcohol effect on sleep electroencephalography by fast Fourier transformation.

The influence of alcohol (ethanol) on sleep was investigated in 10 men. Polysomnography (PS) was recorded on a baseline night (BL-N) and an ethanol (0.8 g/kg) night (Et-N). On visual score rapid eye movement (REM) sleep was reduced, REM latency was prolonged on Et-N as compared to BL-N. Using the fast Fourier transformation method, electroencephalographic power density of REM sleep in delta frequencies band and in the 10-12 Hz range of non-REM sleep were enhanced. REM sleep and non-REM sleep changes were prominent in the second-half and first-half of the night, respectively.

Adult↗
PubMed1998

TGF-beta1 influences early gingival wound healing in rats: an immunohistochemical evaluation of stromal remodelling by extracellular matrix molecules and PCNA.

The effect of topically applied transforming growth factor beta1 (TGF-beta1) on the rat gingival wound healing process after flap surgery was evaluated by immunohistochemistry for extracellular matrix molecules (ECM), such as tenascin, heparan sulfate proteoglycan (HSPG) and type IV collagen, and for proliferating cell nuclear antigen (PCNA) in fibroblasts. TGF-beta1 solution was applied to the surgical wound experimental sites. Two microg/microl were applied at the time of the operation, and 1 microg/microl at days 1 and 2 after surgery, with contralateral control sites receiving the vehicle alone. Periodontal tissues were histologically examined at 3 and 7 days post-surgery. Tenascin was found to be more strongly stained in the granulation tissue from experimental sites at 3 days post-surgery. At 7 days postsurgery, HSPG-positive areas in granulation tissue had become smaller and there was a prominent proliferation of PCNA-positive fibroblast-like cells and type IV collagen-positive blood vessels. These results suggest that TGF-beta1 applied to surgical wounds influences early proliferation of gingival fibroblast-like cells, the formation of blood vessels, and ECM remodelling. In conclusion, TGF-beta1 application appears to promote granulation tissue formation in periodontal wound healing.

Animals↗
PubMed1998

Differential gene expression of TGF-beta isoforms and TGF-beta receptors during the first trimester of pregnancy at the human maternal-fetal interface.

PROBLEM: The transforming growth factor (TGF)-beta s are multifunctional cytokines, and they play a role in the controlled growth of trophoblasts. Moreover they are thought to be important in maternal-fetal interaction during early gestation. METHOD OF STUDY: Human decidual and villous tissues in the first trimester were Northern blotted and amplified by reverse transcription-polymerase chain reaction to measure the expression of TGF-beta 1, -beta 2, and -beta 3 and their receptors, types I and II, at the first trimester of pregnancy. In addition, their cell-specific expression at the maternal-fetal interface was determined by in situ hybridization. RESULTS: Each isoform of TGF-beta was expressed in both decidual and villous tissues. Because most TGF-beta 1 gene expression was found in villous tissues, TGF-beta 2 mRNA was expressed preferentially in the decidual tissues. TGF-beta 3 transcripts were expressed in the nonpregnant endometrium. CONCLUSIONS: The results suggest that each isoform of TGF-beta plays some specific role in decidualization and placentation. Furthermore, it is predicted that they regulate the maternal-fetal interaction at early gestation.

Blotting, Northern↗
PubMed1998

Comparison of intranasal and intramuscular immunization against human immunodeficiency virus type 1 with a DNA-monophosphoryl lipid A adjuvant vaccine.

We compared immune responses to intranasal and intramuscular DNA vaccinations against human immunodeficiency virus type 1 with monophosphoryl lipid A (MPL) used as an adjuvant. Both routes of vaccination resulted in similar levels of cell-mediated immunity, but the intestinal secretory immunoglobulin A response was higher following intranasal immunization than after intramuscular immunization. MPL demonstrated its adjuvanticity in vaccination by both routes.

AIDS Vaccines↗
PubMed1998

Dentilisin activity affects the organization of the outer sheath of Treponema denticola.

Prolyl-phenylalanine-specific serine protease (dentilisin) is a major extracellular protease produced by Treponema denticola. The gene, prtP, coding for the protease was recently cloned and sequenced (K. Ishihara, T. Miura, H. K. Kuramitsu, and K. Okuda, Infect. Immun. 64:5178-5186, 1996). In order to determine the role of this protease in the physiology and virulence of T. denticola, a dentilisin-deficient mutant, K1, was constructed following electroporation with a prtP-inactivated DNA fragment. No chymotrypsin-like protease activity was detected in the dentilisin-deficient mutant. In addition, the high-molecular-mass oligomeric protein characteristic of the outer sheath of the organism decreased in the mutant. Furthermore, the hydrophobicity of the mutant was decreased, and coaggregation of the mutant with Fusobacterium nucleatum was enhanced compared to that of the wild-type organism. The results obtained with a mouse abscess model system indicated that the virulence of the mutant was attenuated relative to that of the wild-type organism. These results suggest that dentilisin activity plays a major role in the structural organization of the outer sheath of T. denticola. The loss of dentilsin activity and the structural change in the outer sheath affect the pathogenicity of T. denticola.

Animals↗
PubMed1998

Induction of systemic and mucosal immune responses to human immunodeficiency virus type 1 by a DNA vaccine formulated with QS-21 saponin adjuvant via intramuscular and intranasal routes.

Induction of mucosal and cell-mediated immunity is critical for development of an effective vaccine against human immunodeficiency virus (HIV). We compared intramuscular and intranasal immunizations with a DNA vaccine encoding env of HIV-1 and evaluated the QS-21 saponin adjuvant for augmentation of the systemic and mucosal immune responses to HIV-1 in a murine model. Vaccination via the two routes elicited comparable systemic immune responses, and QS-21 consistently enhanced antigen-specific serum immunoglobulin G2a (IgG2a) production, delayed-type hypersensitivity reaction, and cytolytic activity of splenocytes. Intestinal secretory IgA production and cytolytic activity of the mesenteric lymph node cells are preferentially elicited by intranasal immunization, and QS-21 augmented these activities as well. This adjuvant augmented production of interleukin-2 (IL-2) and gamma interferon (IFN-gamma) associated with decrease in IL-4 synthesis by antigen-restimulated splenocytes. The serum immunoglobulin subtype profile showed a dominant IgG2a response and less strong IgG1 and IgE production in a QS-21 dose-dependent manner. As expected, enhancements of humoral and cell-mediated immune responses by QS-21 were abrogated by treatment with anti-IL-2 and anti-IFN-gamma monoclonal antibodies. These results suggest that the intranasal route of DNA immunization is more efficient than the intramuscular route in inducing mucosal immunity mediated by sIgA and mesenteric lymphocytes. Furthermore, QS-21 is able to act as a mucosal adjuvant in DNA vaccination and demonstrates its immunomodulatory property via stimulation of the Th1 subset. This study emphasizes the importance of the route of immunization and the use of an adjuvant for effective DNA vaccination against HIV-1.

Adjuvants, Immunologic↗
PubMed1998

Expression and purification of biologically active porcine follicle-stimulating hormone in insect cells bearing a baculovirus vector.

Biologically active recombinant porcine FSH (rec-pFSH) free from the cognate pituitary glycoprotein hormone LH was produced. It was synthesized by a baculovirus vector-insect cell system using two cDNAs encoding the glycoprotein alpha and FSH beta subunits. Its antigenicity was the same as that of pFSH prepared from the pituitary. Glycosylation of rec-pFSH was shown by tunicamycin treatment but the molecular mass of each subunit was lower than that of pituitary-derived FSH, because of the absence of trimming of terminal sugars in insect cells. Rec-pFSH was secreted into the culture medium at about 1 mg/l and purified in six fractions, because of the heterogeneity of the sugar group, by S-Sepharose and concanavalin A-Sepharose column chromatography. The biological activity of rec-pFSH was examined by measuring its effect on progesterone secretion from porcine granulosa cells and germinal vesicle breakdown (GVBD) of porcine oocytes. It showed adequate activity with respect to progesterone secretion, although some fractions rich in the sugar group showed lower activity than that of pituitary-derived FSH. It exhibited higher GVBD activity than that of pituitary-derived FSH at concentrations as low as 1 ng/ml. These results demonstrate that the baculovirus vector-insect cell system can provide biologically active rec-pFSH.

Animals↗
PubMed1998

Dynamics of serum immunoglobulin G avidity for Porphyromonas gingivalis in adult periodontitis.

The purpose of this study was to examine avidity of immunoglobulin G (IgG) antibody for surface antigens of Porphyromonas gingivalis in sera from patients with adult periodontitis. The antigens used were whole cell antigens, lipopolysaccharides (LPS), and fimbriae of non-invasive P. gingivalis ATCC 33277 and invasive 16-1. Serum IgG titers for the P. gingivalis antigens were measured by enzyme-linked immunosorbent assay (ELISA) before and after periodontal initial preparation. IgG avidity was measured by diethylamine dissociation ELISA. IgG titers for the whole cell antigens of 16-1, LPS, and the fimbria antigens from both P. gingivalis strains were significantly higher in the patient group than those in the control group, whereas values for avidities were significantly lower in patient sera. Although we found a statistically significant decrease in the IgG titers of patients following initial preparation, avidities against the fimbria antigen of invasive 16-1 strain increased. The present study showed that IgG antibodies elicited in patients were different in their ability to respond to invasive P. gingivalis 16-1 and to non-invasive 33277. The patient sera with high IgG titers demonstrated low values for avidity, suggesting that IgG responses in patients play a limited role in colonization inhibition or elimination of P. gingivalis. The data indicate that periodontally healthy individuals may have highly functional antibodies which may protect against P. gingivalis colonization. Our findings suggest that the ability to produce functional antibodies in the patient group is lower than that in the periodontally healthy group, but the functional antibodies can be induced by the initial preparation.

Adult↗
PubMed1998

The efficacy of antimicrobial mouth rinses in oral health care.

There is growing public recognition of the importance of oral health, as symbolized by the theme. "Oral Health for a Healthy Life" proposed for the 1994 World Health Day. In this report, the efficacy of antimicrobial mouth rinses, mainly Listerine, was reviewed by three investigators who are working as a microbiologist, a microbiologist, a dentist, and a dental hygienist participating in oral health care. Listerine, an antimicrobial mouth rinse, completely killed microorganisms in 10 to 30 seconds; the microbes includes methicillin-resistant Staphylococcus aureus, Streptococcus pyogenes, Helicobacter pylori, Candida albicans, Streptococcus mutans, Actinomyces viscosus, Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans. Listerine was also weakly effective in inactivating human immunodeficiency viruses. Bacteria in samples collected from human dental plaque and saliva were completely killed within 30 seconds when exposed to Listerine. When saliva samples were collected from subjects who had rinsed their mouths with 20 ml of Listerine or 1:50 diluted povidone-iodine, levels of viable anaerobic bacteria in the samples were reduced to 1%. When Listerine was used for oral surgery such as tooth extraction and periodontal surgery, the agent was effective in relieving toothache. This was probably due to a decrease in oral bacteria by the antimicrobial action of Listerine, leading to lowering the inflammatory response of the host. The use of antimicrobial mouth rinse during dental treatments such as endodontic treatment proved effective for more reliable infection control. In Japan, there are an increasing number of elderly and medically compromised hosts who are potentially at risk for developing pneumonia due to silent aspiration of microbes in the oral cavity and throat. For the aged with such potential risk, using of antimicrobial mouth rinse may be effective in preventing dental plaque accumulation when used in addition to the mechanical control of plaque, since they tend to have difficulty in brushing teeth by themselves. Indeed, the use of antimicrobial mouth rinse in these elderly people proved useful not only in preventing bacterial pneumonia, but also in improving their quality of life by preserving their oral health.

Aged↗
PubMed1998

Effect of metabolic substrate on BMIPP metabolism in canine myocardium.

UNLABELLED: The lipid tracer 1 5-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) is clinically useful, and its basic metabolism is being analyzed. Because the pharmacokinetics of this lipid tracer may be affected by blood concentrations of fatty acid or glucose, this study evaluated the effects of excess levels of lipid or glucose on BMIPP uptake and metabolism. METHODS: A technique using an open-chest dog model was used. Blood sampling was performed from the left anterior descending coronary artery and great cardiac vein after an injection of 123I-BMIPP either with a glucose infusion (n = 6) or a lipid infusion (n = 5). High performance liquid chromatography and double-tracer kinetic analyses clarified the extraction, retention, backdiffusion and further metabolism of BMIPP. These results were compared with data from control dogs (n = 6). RESULTS: In this experiment, a 10-fold increase over the normal lipid blood concentration and twofold increase over the normal blood glucose concentration were evaluated with either intralipid or glucose infusion, respectively. In the lipid infusion studies, the extraction significantly decreased compared with the control values (74% +/- 12% to 58% +/- 8%; p < 0.05), and the washout increased from 50% +/- 13% to 68% +/- 16% (p < 0.05). The BMIPP backdiffusion increased (p < 0.05), and the levels of the further metabolites decreased (p < 0.05), while the retention level remained constant (normal, 89% +/- 9%; lipid infusion, 91% +/- 3%; ns). In the glucose infusion studies, the BMIPP extraction, retention and washout showed no statistical differences compared to controls; however, these parameters showed the same tendencies as those in the lipid infusion group. In addition, the BMIPP backdiffusion increased significantly (control, 25.1% +/- 8%; glucose infusion, 48.7% +/- 25.6%; p < 0.05) as it did after the lipid infusion. CONCLUSION: BMIPP metabolism and uptake are affected by excess concentrations of lipid and glucose in the blood. However, the retention of BMIPP was not affected by either type of infusion. The BMIPP backdiffusion and the further metabolite comprising 10% of the tracer extracted were affected both by the lipid and glucose infusions. These results indicate that an excess fat concentration and glucose affect BMIPP uptake, especially the extraction of BMIPP and BMIPP backdiffusion.

Animals↗
PubMed1998

[A case of linear sebaceous nevus syndrome associated with a cerebrovascular anomaly].

We report a 34-year-old woman with linear sebaceous nevus syndrome and dolichomegalic artery. The patient was admitted to our hospital for evaluation of a headache and fever. Neurological examination revealed no focal sign except neck stiffness. She had had sebaceous nevi on the left side of her head, cheek and neck since she was born. A cranial CT scan showed high signal intensity in the subarachnoid space. Cranial MRI showed a dolichomegalic artery. The patient's past history included many episodes of headache and fever since her first decade of life and she had been diagnosed five times with cerebrovascular disease. At the present admission, subarachnoid hemorrhage was diagnosed and treated. The patient improved and was discharged on the 21st day. Linear sebaceous nevi are associated with many types of anomalies, but we found no other reported cases of linear sebaceous nevus syndrome associated with a cerebrovascular anomaly. This case suggests that a patient with sebaceous nevi who presents with headache and fever should be examined with careful attention to the cerebrovascular system.

Adult↗