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Biomedical subjects

N Iida

Publications and source records attributed to N Iida.

At least 19 recordsLinked to original sources
PubMed2003

Determination of residual double bonds in resin-dentin interface by Raman spectroscopy.

OBJECTIVES: The quality of the hybrid layer is believed to be more important than the thickness of this layer. The purpose of this study was to investigate a method to analyze the percentage of adhesive resin residual double bonds in the dentin-resin interface using laser Raman spectroscopy. METHODS: Bovine dentin was treated with dentin adhesives and resin composite was bonded according to the manufacturers' instructions. The specimens were sectioned parallel to dentinal tubules and the surfaces were then polished to 1 microm diamond pastes. Raman spectra were recorded along a line perpendicular to the dentin-resin interface in steps of 0.2 microm. The measurement of residual C=C bond was made on a relative basis by comparing the C=C unpolymerized methacrylate stretching vibration (1638 cm(-1)) against the C=O stretching mode of the ester group (1719 cm(-1)). The percentage of residual double bonds including pendant and monomeric double bonds was calculated by comparing the obtained ratio with that of uncured adhesive resin. RESULTS: The amount of residual double bonds in the hybrid layer varied from 10 to 25% compared to the uncured adhesives, a relatively higher percentage was detected for Fluoro Bond (12.3-23.6%) and Single Bond (9.5-21.8%), and lower for Mac Bond II (10.6-18.0%) and Mega Bond (10.7-16.3%). No relationship was seen between the percentage of remaining double bonds and the location within the resin-dentin interface. SIGNIFICANCE: Laser Raman microscopy used was a useful tool for measuring the residual double bonds in the dentin-resin interface.

Analysis of Variance↗
PubMed2002

Lessons from similarities between SLE and HIV infection.

OBJECTIVE: We attempted to obtain deeper understanding of systemic lupus erythematosus (SLE) and human immunodeficiency virus (HIV) infection through comparative studies between both diseases. METHOD: For this purpose, we reviewed and discussed lessons from similarities in both diseases based on our own and reported findings in literatures. RESULT: Such comparative studies may contribute to the progress in understanding the clinical or pathogenetic features of these diseases. CONCLUSION: Further studies into the relationship between SLE and HIV infection may bring to light important clues to assist in the development of better treatments for each disease.

HIV Infections↗
PubMed2002

Allergic disorders in systemic lupus erythematosus: prevalence and family history.

The relationship between allergic disorders (such as atopic dermatitis, asthma, allergic rhinitis and allergic conjunctivitis) and systemic lupus erythematosus (SLE) is still unclear and controversial. We investigated the prevalence of these allergic disorders in SLE patients and their families. A questionnaire about the history of allergy was completed by 52 SLE patients and by 52 matched (including race, age, sex and region) non-SLE controls. Our results indicated that there was a significantly lower incidence of these allergic diseases in SLE patients, especially those who had an allergic family histories, when compared with the controls. These findings may be related to the immunological similarities and differences between SLE and various allergic diseases.

Adolescent↗
PubMed2002

Discrete roles of cytokines, TNF-alpha, IL-1, IL-6 in tumor promotion and cell transformation.

Based on our previous results, which pointed to tumor necrosis factor-alpha (TNF-alpha) as the essential cytokine in tumor promotion in mouse skin, we present here three principal findings related to the specific roles of TNF-alpha, interleukin-1 (IL-1) and IL-6 in tumor promotion (using TNF-alpha- and IL-6-deficient mice) and in BALB/3T3 cell transformation: i) The previously reported residual tumor promotion by 12-O-tetradecanoylphorbol-13-acetate (TPA) in TNF-/- mice was confirmed by experiments with TNF+/+ and TNF-/- 129/Svj mice of the same strain, using two-stage carcinogenesis experiments. TPA produced tumors in 100% of TNF+/+ and 78% of TNF-/- mice at 20 weeks, and the average number of tumors per mouse was 11.1 in the former group and 2.1 in the latter. Judging from the expression of various inflammatory cytokine genes in TNF+/+ and TNF-/- mice, the residual tumor promoting activity of TPA in TNF-/- mice may be dependent on expression of IL-1alpha and IL-1beta genes. ii) Tumor promotion by TPA and okadaic acid in IL-6+/+ and IL-6-/- C57/BL6 mice was studied, with TPA producing tumors in 57.1% of IL-6+/+ and 40.0% of IL-6-/- mice at 20 weeks, and okadaic acid in 40.0% of IL-6+/+ and 53.3% of IL-6-/- mice. Thus, there was no significant difference between TPA or okadaic acid tumor promotion in either group. In addition, expression of IL-6 gene in skin of both types of mice suggested that IL-6 is not the essential cytokine in tumor promotion, since it can be replaced by other cytokines. iii) In transformed clones of BALB/3T3 cells induced by TNF-alpha alone, IL-1alpha gene expression was induced after transformation by TNF-alpha had occurred, which did not occur in parental cells. Expression patterns of TNF-alpha, IL-1beta, IL-6 and IL-10, along with TGF-beta, were similar in both parental and transformed cells. Considering all these results, we conclude that various cytokines have discrete roles in tumor promotion and cell transformation.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2001

Requirement of Ras for the activation of mitogen-activated protein kinase by calcium influx, cAMP, and neurotrophin in hippocampal neurons.

Mitogen-activated protein (MAP) kinase plays important roles in the establishment of long-term potentiation both in vitro and in living animals. MAP kinase is activated in response to a broad range of stimuli, including calcium influx through NMDA receptor and L-type calcium channel, cAMP, and neurotrophins. To investigate the role of Ras in the activation of MAP kinase and cAMP response element-binding protein (CREB) in hippocampal neurons, we inhibited Ras function by overexpressing a Ras GTPase-activating protein, Gap1(m), or dominant negative Ras by means of adenovirus vectors. Gap1(m) expression almost completely suppressed MAP kinase activation in response to NMDA, calcium ionophore, membrane depolarization, forskolin, and brain-derived neurotrophic factor (BDNF). Dominant negative Ras also showed similar effects. On the other hand, Rap1GAP did not significantly inhibit the forskolin-induced activation of MAP kinase. In contrast to MAP kinase activation, the inactivation of Ras activity did not inhibit significantly NMDA-induced CREB phosphorylation, whereas BDNF-induced CREB phosphorylation was inhibited almost completely. These results demonstrate that Ras transduces signals elicited by a broad range of stimuli to MAP kinase in hippocampal neurons and further suggest that CREB phosphorylation depends on multiple pathways.

Adenoviridae↗
PubMed2001

Use of bilateral retroangular flaps for reconstruction of the glabella and nose.

We report the use of bilateral retroangular flaps for reconstruction of the glabella and nasal tip following extirpation of a cavernous haemangioma. The vascularity of the flaps was good, and the colour and texture match excellent. Donor-site closure was easy, and the scar in the nasolabial groove was not conspicuous. Our experience demonstrates that this flap is useful for reconstruction of skin defects of not only the nose but also the glabella and forehead. By raising bilateral flaps, a wide skin defect in the centre of the face can be repaired.

Adult↗
PubMed2001

Pseudolymphoma of the liver associated with Sjögren's syndrome.

Sjögren's syndrome (SS) is known to be associated with pseudolymphoma in several organs. We describe a patient with SS complicated by a hepatic pseudolymphoma. Although the development of a hepatic pseudolymphoma is extremely rare, this disorder should be taken into consideration in the differential diagnosis of space occupying lesions related to autoimmune diseases such as SS.

Female↗
PubMed2001

Reversal effects of antifungal drugs on multidrug resistance in MDR1-overexpressing HeLa cells.

In this study, the antiproliferative effects of vinblastine (VLB), paclitaxel (TXL), doxorubicin (DXR), daunorubicin (DNR) and 5-fluorouracil (5-FU) were assessed in the human cervical carcinoma cell line HeLa-Ohio (HeLa) and Hvr100-6 cells, established by growing the parental HeLa cells in the presence of progressively greater concentrations of VLB in the culture medium. Flow cytometric analysis indicated the induction of MDR1 (P-glycoprotein) in Hvr100-6 cells with no alterations in levels of multidrug resistance-associated protein (MRP). Resistance to VLB, TXL, DXR and DNR was found in Hvr100-6 cells with relative resistances of ca. 300, 4000, 50 and 200, respectively, whereas no resistance was found to 5-FU. The reversal effects of antifungal drugs, fluconazole, itraconazole, ketoconazole, miconazole and amphotericin B on multidrug resistance were also assessed using Hvr100-6 cells. Itraconazole was found to have potent reversal effect on the resistance to VLB and TXL, but the others had no such effect. This reversal effect of itraconazole was concentration-dependent, with dose modifying factors of 3.2, 10.1 and 435.7 at 0.1, 0.25 and 0.5 microM of itraconazole, respectively. In addition, this reversal effect of itraconazole was explained by the inhibition of accumulation of the anticancer drugs.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Is compensatory vasoconstrictor tone in the hindquarter vascular region induced by hemorrhage in conscious spontaneously hypertensive rats?

We investigated whether a compensatory vasoconstrictor action would be induced by a hypotensive intervention in the hindquarter vascular region of conscious spontaneously hypertensive rats (SHRs). Mean arterial pressure and hindquarter blood flow were recorded. After hemorrhage (withdrawing blood, 0.3 ml/100 g body weight), hindquarter resistance (HQR) was increased significantly. The decrease in HQR induced by the administration of a ganglionic blocker (C6; 25 mg/kg, i.v.) was significantly greater in SHRs with hemorrhage than in those without hemorrhage. The present results suggest that a detectable hindquarter compensator tone occurs due to hemorrhage in SHRs, although an abnormal substantial vasoconstrictor tone already exists in the hindquarters.

Animals↗
PubMed2000

Changes of CD4/CD8 ratio and interleukin-16 in systemic lupus erythematosus.

The authors investigated changes in the ratio of CD4+ to CD8+ T cells (CD4/CD8 ratio) and T-cell activation, indicated by human leukocyte antigen (HLA)-DR expression, in patients with systemic lupus erythematosus (SLE) following treatment. An increase was observed in the CD4/CD8 ratio as well as a decrease in the expression of HLA-DR on T cells with the improvement of clinical manifestations on treatment with steroids or cyclosporine (CSA). In addition, steroid treatment suppressed whereas CSA treatment exerted no perceptible influence on the serum interleukin (IL)-16 level, concurrent with changes in T-cell phenotypes. This indicated that the mechanism of the change in the CD4/CD8 ratio differed depending on the drug, and CD8+ T cells could play an important role in reducing this ratio. The CD4/CD8 ratio and HLA-DR expression may be good indicators of therapeutic efficacy in some SLE patients.

Adrenal Cortex Hormones↗
PubMed2000

In vivo detection of ultraviolet photoproducts and their repair in purkinje cells.

We previously developed a highly sensitive method to assess in situ repair kinetics of ultraviolet (UV)-induced DNA photoproducts in epidermal cells using monoclonal antibodies specific for cyclobutane pyrimidine dimers (CPDs) and pyrimidine-pyrimidone (6-4) photoproducts (64PPs) by immunohistochemistry. In order to determine whether nucleotide excision repair capacity is operative in postmitotic mature neurons, brain surfaces of adult mice were exposed to UVB, and induction and removal of CPDs and 64PPs in Purkinje cell DNA were assessed immunohistochemically. UVB penetrated brain tissue to a depth sufficient to allow quantitative study. CPDs but not 64PPs were clearly detectable in the nuclei of Purkinje cells at doses >500 J/m2, in a dose-dependent manner. A time course experiment showed a statistically significant decrease of CPDs with time after irradiation. Although there was no apparent removal on Day 1, about half of CPDs were removed within 5 days, and the repair was essentially completed by Day 10. We conclude that non-dividing cerebellar neuronal cells can indeed repair UV-induced DNA damage, but with relatively low efficiency as compared with dividing epidermal cells.

Animals↗
PubMed2000

Addition of metronidazole to rabeprazole-amoxicillin-clarithromycin regimen for Helicobacter pylori infection provides an excellent cure rate with five-day therapy.

BACKGROUND: New triple therapy for eradication of Helicobacter pylori based on a proton pump inhibitor (PPI) provides a cure rate of approximately 90% with few adverse effects. Recently, a PPI-based quadruple therapy, which consists of a PPI plus bismuth-based triple therapy for 7 days, has been studied, and a sufficient eradication rate has been achieved. However, a shorter duration results in improved compliance. In this study, newly developed short-term, simple twice-daily quadruple therapy consisting of rabeprazole, amoxicillin, clarithromycin, and metronidazole (RACM) was compared with a PPI-based triple-therapy regimen for eradication of H. pylori. PATIENTS AND METHODS: This study was designed as a randomized open, prospective single-center study. Of a total of 105 H. pylori-positive patients, 55 received the RACM regimen for 5 days (rabeprazole, 10 mg bid; amoxicillin, 750 mg bid; clarithromycin, 200 mg bid; and metronidazole, 250 mg bid), and 50 received the RAC regimen for 5 days (rabeprazole, 10 mg bid; amoxicillin, 750 mg bid; and clarithromycin, 200 mg bid). Cure of the infection was assessed by HpSA (H. pylori stool antigen immunoassay) 1 month after completion of therapy. RESULTS: The rates of eradication of H. pylori by RACM versus RAC were 94.5% (95% CI, 85-99) versus 80.0% (95% CI, 66-90) by intention-to-treat analysis; 98.1% (95% CI, 90-100) versus 87.0% (95% CI, 74-95) by all-patients-treated analysis; and 98.1% (95% CI, 90-100) versus 86.7% (95% CI, 73-95) by per-protocol analysis. No major adverse effects were reported, and 98.0% of patients reported complete compliance. CONCLUSIONS: The simple twice-daily and short-term quadruple regimen for only 5 days provided an excellent eradication rate. Compliance with the regimen was high, and serious adverse effects were few. Therefore, the RACM regimen can be considered as safe and effective.

2-Pyridinylmethylsulfinylbenzimidazoles↗