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1.
Pharmazie ; 73(7): 393-395, 2018 07 01.
Article in English | MEDLINE | ID: mdl-30001773

ABSTRACT

Lycopene, the main fat-soluble pigment responsible for the red color of ripe tomatoes, is a symmetrical tetraterpene comprising eight isoprene units. In vitro and in vivo studies have shown that lycopene acts as a potent antioxidant; it is 100 times more effective than vitamin E and 125 times more effective than glutathione as an antioxidant. Here, we divided BALB/c male mice into three equal groups: control, Concanavalin A (Con A), and Con A and lycopene. The control group mice received only vehicle by intraperitoneal injection, the Con A group mice were given Con A, and the Con A and lycopene group mice received Con A and lycopene. The results showed that Con A administration increased histopathological damage, and the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), interleukin (IL)-6, interferon (IFN)-γ and tumor necrosis factor (TNF)-α were increased in serum samples whereas the levels of these compounds were significantly decreased in the Con A and lycopene group compared to the Con A group. Furthermore, we observed that lycopene led to an increase in cell viability and cell growth. The results of this study revealed that lycopene might be a useful hepatoprotective agent for reducing increased proinflammatory cytokine levels, and for increasing cell viability and cell growth.


Subject(s)
Antioxidants/pharmacology , Cell Survival/drug effects , Liver Diseases/prevention & control , Lycopene/pharmacology , Alanine Transaminase/blood , Animals , Aspartate Aminotransferases/blood , Concanavalin A/toxicity , Disease Models, Animal , Interferon-gamma/blood , Interleukin-6/blood , Male , Mice , Mice, Inbred BALB C , Tumor Necrosis Factor-alpha/blood
2.
Pharmazie ; 73(3): 165-168, 2018 03 05.
Article in English | MEDLINE | ID: mdl-29544565

ABSTRACT

Recently, with the advancement of nanotechnology, various nanoparticles have been developed and used in fields such as electronics, cosmetics, and foods. However, the toxicity of nanoparticles has yet to be fully investigated. In particular, the interactions between nanoparticles and therapeutic drugs require further study. We previously reported that unmodified polystyrene nanoparticles with a particle size of 50 nm (NPP50) co-administered with paraquat (PQ) or cisplatin (CDDP) induce hepatic and kidney injury. Here, we determined if NPP50 modified with the amino group (NPP50-NH2), carboxyl group (NPP50-COOH), or palladium (Pd-NPP50) caused liver or kidney injury when co-administered with PQ or CDDP. The results showed that when NPP50-NH2, NPP50-COOH, or Pd-NPP50 was administered alone via the mouse tail vein, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and blood urea nitrogen (BUN) did not increase or cause injury. When NPP50, NPP50-NH2, NPP50-COOH, or Pd-NPP50 was co-administered with PQ, serum levels of ALT and AST increased in the NPP50 group but did not increase in the NPP50-NH2, NPP50-COOH, or Pd-NPP50 groups. When NPP50-NH2, NPP50-COOH, or Pd-NPP50 was co-administered with CDDP, ALT, AST, and BUN values did not increase. These data suggest that injury due to the interaction of polystyrene nanoparticles with CDDP or PQ can be suppressed by changes in the surface charge of nanoparticles or by Pd modification.


Subject(s)
Antineoplastic Agents/administration & dosage , Antineoplastic Agents/therapeutic use , Chemical and Drug Induced Liver Injury/pathology , Cisplatin/chemistry , Cisplatin/therapeutic use , Herbicides/chemistry , Herbicides/toxicity , Kidney Diseases/chemically induced , Nanoparticles/chemistry , Palladium/chemistry , Palladium/pharmacology , Paraquat/chemistry , Paraquat/toxicity , Alanine Transaminase/blood , Animals , Aspartate Aminotransferases/blood , Blood Urea Nitrogen , Kidney Diseases/pathology , Male , Mice , Mice, Inbred BALB C , Particle Size , Polystyrenes
3.
Sci Rep ; 7(1): 6130, 2017 07 21.
Article in English | MEDLINE | ID: mdl-28733661

ABSTRACT

We theoretically show that a single free electron in circular motion radiates an electromagnetic wave possessing helical phase structure, which is closely related to orbital angular momentum carried by it. We experimentally demonstrate it by interference and double-slit diffraction experiments on radiation from relativistic electrons in spiral motion. Our results indicate that photons carrying orbital angular momentum should be created naturally by cyclotron/synchrotron radiations or Compton scatterings in various situations in cosmic space. We propose promising laboratory vortex photon sources in various wavelengths ranging from radio wave to gamma-rays.

4.
Phys Rev Lett ; 118(9): 094801, 2017 Mar 03.
Article in English | MEDLINE | ID: mdl-28306317

ABSTRACT

We theoretically demonstrate for the first time that a single free electron in circular or spiral motion emits twisted photons carrying well-defined orbital angular momentum along the axis of the electron circulation, in adding to spin angular momentum. We show that, when the electron velocity is relativistic, the radiation field contains harmonic components and the photons of lth harmonic carry lℏ total angular momentum for each. This work indicates that twisted photons are naturally emitted by free electrons and are more ubiquitous in laboratories and in nature than ever thought.

5.
Pharmazie ; 72(1): 10-16, 2017 Jan 10.
Article in English | MEDLINE | ID: mdl-29441891

ABSTRACT

Nanomaterials are frequently used in microelectronics, cosmetics, and sunscreens. Platinum reagents are commonly used in disease diagnosis, cosmetics, and the food industry. Although research into the development of nanomaterialbased drug delivery systems has yielded promising results, the toxicity of these materials is not fully understood. We investigated the toxicity and drug interactions of 1- and 8-nm diameter platinum nanoparticles (nPt1 and nPt8, respectively) in mice. Acute hepato-renal toxicity of intravenously administered platinum nanoparticles was evaluated biochemically and histologically. Dose-dependent increases in serum markers of hepato-renal function (serum aminotransferases and blood urea nitrogen) were observed following administration of nPt1, whereas nPt8 had no effect, even at 20 mg/kg. Moreover, nPt1 induced interleukin (IL)-6 and IL-1ß production 3 and 6 hours after administration. The effect of nPts on drug-induced toxicity was evaluated in mice injected intraperitoneally with carbon tetrachloride or cisplatin, with or without intravenous administration of platinum nanoparticles. All treatments in the absence of nanoparticles were non-lethal and resulted in moderate toxicity. However, exacerbated toxicity was observed in mice injected with carbon tetrachloride or cisplatin together with nPt1, but not in mice co-injected with nPt8. We found that nPt1 cause hepato-renal damage, and the effect is enhanced by chemical inducers of hepatotoxicity and nephrotoxicity. This is the first report demonstrating that nPt1 not only are hepatotoxic and nephrotoxic but also exacerbate drug toxicity. These findings will be useful for future nanotechnology and nanoscience research.


Subject(s)
Chemical and Drug Induced Liver Injury/pathology , Kidney Diseases/chemically induced , Kidney Diseases/pathology , Metal Nanoparticles/toxicity , Platinum/toxicity , Alanine Transaminase/blood , Animals , Antineoplastic Agents/toxicity , Aspartate Aminotransferases/blood , Blood Urea Nitrogen , Carbon Tetrachloride/toxicity , Cisplatin/toxicity , Dose-Response Relationship, Drug , Drug Interactions , Interleukin-1beta/biosynthesis , Interleukin-1beta/genetics , Interleukin-6/biosynthesis , Interleukin-6/genetics , Male , Mice , Mice, Inbred BALB C , Particle Size
6.
Radiat Prot Dosimetry ; 171(1): 23-6, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27473692

ABSTRACT

Radiological specialists from Nagasaki University have served on the medical relief team organized at Fukushima Medical University Hospital (Fukushima City) ever since the accident at the Fukushima Dai-ichi nuclear power plant. Furthermore, we have conducted the radiation crisis communication efforts by spreading correct information on the health effects of radiation as 'advisors on radiation health risk control'. Nagasaki University has been assisting the reconstruction efforts of Kawauchi Village in Fukushima Prefecture, which was the first village to declare that residents could safely return to their homes because radiation doses were found to be at comparatively low levels. In April 2013, Nagasaki University and the Kawauchi government office concluded an agreement concerning comprehensive cooperation toward reconstruction of the village. As a result, we established a satellite facility of the university in the village. In conclusion, training of specialists who can take responsibility for long-term risk communication regarding the health effects of radiation as well as crisis communication in the initial phase of the accident is an essential component of all such recovery efforts. Establishment of a training system for such specialists will be very important both for Japan and other countries worldwide.


Subject(s)
Environmental Monitoring/methods , Fukushima Nuclear Accident , Health Communication/methods , Radiation Injuries/psychology , Radiation Monitoring/methods , Radiation Protection/methods , Risk , Emergencies , Geography , Humans , Japan , Nuclear Power Plants , Radiation Injuries/prevention & control , Radioactive Hazard Release , Residence Characteristics , Soil Pollutants, Radioactive/analysis
7.
Diagn Interv Imaging ; 96(7-8): 687-91, 2015.
Article in English | MEDLINE | ID: mdl-26119866

ABSTRACT

This article proposes an innovative concept of interventional radiology for hemodynamically unstable trauma patients. Damage control interventional radiology (DCIR) is an aggressive and time-conscious algorithm that prioritizes saving life of the hemorrhaging patient in extremis which conventional emergency interventional radiology (CEIR) cannot efficiently do. Briefly, DCIR aims to save life while CEIR aims to control bleeding with a constant concern to time-awareness. This article also presents the concept of "Prompt and Rapid Endovascular Strategies in Traumatic Occasions" (PRESTO) that entirely oversees and manages trauma patients from arrival to the trauma bay until initial completion of hemostasis with endovascular techniques. PRESTO's "Start soon and finish sooner" relies on the earlier activation of interventional radiology team but also emphasizes on a rapid completion of hemostasis in which DCIR has been specifically tailored. Both DCIR and PRESTO expand the role of IR and represent a paradigm shift in the realm of trauma care.


Subject(s)
Cerebral Hemorrhage, Traumatic/therapy , Embolization, Therapeutic/methods , Emergency Medical Services , Algorithms , Brain Damage, Chronic/diagnosis , Brain Damage, Chronic/prevention & control , Cerebral Hemorrhage, Traumatic/diagnosis , Cooperative Behavior , Early Medical Intervention , Humans , Interdisciplinary Communication , Prognosis , Tomography, X-Ray Computed
8.
Eye (Lond) ; 28(7): 870-9, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24788007

ABSTRACT

PURPOSE: To evaluate the images created in a model eye during simulated cataract surgery. PATIENTS AND METHODS: This study was conducted as a laboratory investigation and interventional case series. An artificial opaque lens, a clear intraocular lens (IOL), or an irrigation/aspiration (I/A) tip was inserted into the 'anterior chamber' of a model eye with the frosted posterior surface corresponding to the retina. Video images were recorded of the posterior surface of the model eye from the rear during simulated cataract surgery. The video clips were shown to 20 patients before cataract surgery, and the similarity of their visual perceptions to these images was evaluated postoperatively. RESULTS: The images of the moving lens fragments and I/A tip and the insertion of the IOL were seen from the rear. The image through the opaque lens and the IOL without moving objects was the light of the surgical microscope from the rear. However, when the microscope light was turned off after IOL insertion, the images of the microscope and operating room were observed by the room illumination from the rear. Seventy percent of the patients answered that the visual perceptions of moving lens fragments were similar to the video clips and 55% reported similarity with the IOL insertion. Eighty percent of the patients recommended that patients watch the video clip before their scheduled cataract surgery. CONCLUSIONS: The patients' visual perceptions during cataract surgery can be reproduced in the model eye. Watching the video images preoperatively may help relax the patients during surgery.


Subject(s)
Cataract/pathology , Models, Biological , Phacoemulsification , Retina/physiology , Video Recording , Vision, Entoptic/physiology , Visual Perception/physiology , Adult , Aged , Aged, 80 and over , Humans , Lens Implantation, Intraocular , Middle Aged , Prospective Studies , Surveys and Questionnaires
9.
Rev Sci Instrum ; 84(5): 053305, 2013 May.
Article in English | MEDLINE | ID: mdl-23742543

ABSTRACT

High-energy ultrashort gamma-ray pulses can be generated via laser Compton scattering with 90° collisions at the UVSOR-II electron storage ring. As an applied study of ultrashort gamma-ray pulses, a new photon-induced positron annihilation lifetime spectroscopy approach has been developed. Ultrashort gamma-ray pulses with a maximum energy of 6.6 MeV and pulse width of 2.2 ps created positrons throughout bulk lead via pair production. Annihilation gamma rays were detected by a BaF2 scintillator mounted on a photomultiplier tube. A positron lifetime spectrum was obtained by measuring the time difference between the RF frequency of the electron storage ring and the detection time of the annihilation gamma rays. We calculated the response of the BaF2 scintillator and the time jitter caused by the variation in the total path length of the ultrashort gamma-ray pulses, annihilation gamma rays, and scintillation light using a Monte Carlo simulation code. The positron lifetime for bulk lead was successfully measured.

10.
Theriogenology ; 74(8): 1499-503, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20615533

ABSTRACT

Although the Tsushima leopard cat (Prionailurus bengalensis euptilurus) is one of the most endangered mammals in Japan, its reproductive physiology and endocrinology have been not elucidated. The objective was to establish the non-invasive monitoring of reproductive endocrinology in a female Tsushima leopard cat and to identify the types of fecal reproductive steroid metabolites in this species. Fecal concentrations of estrogen and progestin were determined by enzyme immunoassays, from 60 d before to 60 d after the last copulation, during three pregnancies. Fecal estrogen metabolite concentrations were increased before/around the mating period and after mid-pregnancy. Fecal progestin metabolite concentrations increased after the last copulation and remained high during pregnancy. The gestation period was 65.0 ± 0.6 d (mean ± SD). Fecal extracts were separated by high-performance liquid chromatography for identification of fecal metabolites. Fecal estrogens were identified as estradiol-17ß and estrone. Fecal progestins during pregnancy contained 5α-reduced pregnanes: 5α-pregnan-3α-ol-20-one, 5α-pregnan-3ß-ol-20-one and 5α-pregnan-3,20-dione, and nonmetabolized progesterone was barely detected in feces. In conclusion, measurement of fecal estrogen and progestin metabolites was effective for noninvasive reproductive monitoring in the Tsushima leopard cat. An immunoassay for fecal estradiol-17ß concentrations seemed useful to monitor follicular activity, whereas an immunoassay with high cross reactivity for 5α-reduced pregnanes was useful to monitor ovarian luteal activity and pregnancy.


Subject(s)
Estrogens/metabolism , Feces/chemistry , Felidae/physiology , Progestins/metabolism , Animals , Chromatography, High Pressure Liquid , Endangered Species , Estrogens/chemistry , Felidae/metabolism , Female , Pregnancy , Progestins/chemistry
11.
Eye (Lond) ; 24(8): 1376-81, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20395973

ABSTRACT

PURPOSE: To compare two ophthalmic viscosurgical devices (OVDs), DisCoVisc (viscous dispersive) and Healon5 (viscoadaptive), in terms of their overall clinical performance during phacoemulsification and intraocular lens (IOL) implantation. METHODS: In 323 patients (DisCoVisc; 157, Healon5; 166), the surgeons evaluated on a three-point scale, the maintenance of anterior chamber (AC) during continuous curvilinear capsulorhexis (CCC), maintenance of AC during IOL implantation, retention during phacoemulsification, ease of injection, facilitation of CCC, transparency during surgery, and ease of removal from the eye. The time needed to completely remove OVDs after IOL implantation was measured. Masked examiners measured intraocular pressure (IOP), corneal thickness, and corneal endothelial cell count up to 90 days postoperatively. RESULTS: DisCoVisc was assessed to be significantly better than Healon5 in maintenance of AC during CCC (P=0.0008, Cochran-Mantel-Haenszel test) and IOL implantation (P=0.0055), retention during phacoemulsification (P=0.0009), ease of injection (P<0.0001), facilitation of CCC (P<0.0001), transparency (P<0.0001), and ease of removal (P<0.0001). The washout time was 29.6+/-13.4 and 36.2+/-17.5 s in the DisCoVisc and Healon5 groups, respectively (P=0.0002, unpaired t-test). The mean endothelial cell loss was 1.8+/-8.7% in the DisCoVisc group and 3.8+/-8.3% in the Healon5 group (P=0.0358). There were no statistically significant between-group differences in IOP and corneal thickness. CONCLUSION: DisCoVisc was better retained in the eye during phacoemulsification and was easier to remove after IOL implantation. The corneal endothelial cell loss was significantly less with DisCoVisc than with Healon5. It was indicated that the whole surgical process can be efficiently covered by DisCoVisc alone.


Subject(s)
Lens Implantation, Intraocular/methods , Phacoemulsification/instrumentation , Aged , Anterior Chamber/pathology , Female , Humans , Hyaluronic Acid/administration & dosage , Lens Implantation, Intraocular/instrumentation , Male , Phacoemulsification/methods , Prospective Studies , Viscoelastic Substances/administration & dosage
12.
J Oral Rehabil ; 33(4): 313-5, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16629887

ABSTRACT

A clinical evaluation of an implant-supported overdenture placed in the edentulous mandible after hemiglossectomy is described. The deltopectoral flap covering the mandibular ridge was replaced with a free mucosal graft. Four Brånemark system implants were inserted into the anterior part of the mandible, but one of the four fixtures did not show osseointegration. The superstructure was designed as a spaced round bar-attachment supported by three implants so as to retain the complete overdenture. In addition to the metal clip, a silicone-based soft denture liner material was applied in the female portion of the attachment so as to prevent the attachment from making a clattering noise upon mastication. Although the overdenture required adjustment at regular intervals, the treatment was successful both aesthetically and functionally for up to at least 10 years.


Subject(s)
Dental Prosthesis, Implant-Supported/methods , Denture, Overlay , Glossectomy/rehabilitation , Jaw, Edentulous/rehabilitation , Carcinoma, Squamous Cell/surgery , Dental Implantation, Endosseous/methods , Glossectomy/methods , Humans , Jaw, Edentulous/surgery , Male , Mandible , Middle Aged , Postoperative Complications , Prosthesis Design , Tongue Neoplasms/surgery , Treatment Outcome
13.
J Oral Rehabil ; 32(2): 151-7, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15641983

ABSTRACT

To improve the physical properties of the pure titanium surface, thin titanium nitride (TiN) films were deposited by means of ion-beam-assisted deposition. Film structure was confirmed as TiN by X-ray diffraction analysis. Surface hardness and abrasion resistance were significantly improved on TiN-coated specimens. Five combinations of oral hygiene instruments and materials were applied to the specimens as simulations of the oral environment. Treatment with the metal scaler and ultrasonic scaler severely changed the surface features and significantly increased the surface roughness parameters on pure titanium controls, whereas only small scratches and dull undulations were seen on the TiN-coated specimens. Profilometric tracings and scanning electron micrographs demonstrated the improved abrasion resistance of the TiN-coated specimens.


Subject(s)
Coated Materials, Biocompatible , Titanium , Dental Alloys , Dental Restoration, Permanent/methods , Humans , Microscopy, Electron, Scanning/methods , Surface Properties , Tooth Abrasion
14.
J Opt Soc Am A Opt Image Sci Vis ; 20(2): 248-55, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12570291

ABSTRACT

We have developed a new technique for generating homogeneously distributed irregular dot patterns useful for optical devices and digital halftoning technologies. To introduce irregularity, we use elaborately designed sequences called low-discrepancy sequences instead of pseudorandom numbers. We also use a molecular-dynamics redistribution method to improve the distribution of dots. Our method can produce arbitrary density distributions in accordance with a given design. The generated patterns are free from visible roughness as well as any moiré patterns when superimposed on other regular patterns. We demonstrate that our method effectively improves luminance uniformity and eliminates moiré patterns when used for a backlight unit of a liquid-crystal display.

15.
J Oral Rehabil ; 29(11): 1052-8, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12453258

ABSTRACT

The purpose of this study was to evaluate five dentin bonding systems simulating indirect restorations. The surface of bovine and human dentin was primed with a glutaraldehyde agent (GLUMA) and placed in a humidor at 37 degrees C for 168 h. In an experimental bonding system (GLUMA/CY/SB), the surfaces were etched with phosphoric acid, primed with cytochrome c, and then bonded to an acrylic rod with a self-curing resin (4-META/MMA-TBB). Specimens using two commercially available bonding systems [All-Bond 2 (AB2) and Super-Bond C & B (10-3/SB)] and two controls with and without GLUMA (GLUMA/10-3/SB and CY/SB) were also prepared. Tensile testing revealed that the bond strengths were influenced by the bonding system, 168 h dentin exposure and their interaction, but not by the tooth origin. AB2 showed the lowest bond strength. With the 10-3/SB system, exposing the dentin to humidity resulted in a decrease in bond strength. After 168 h of exposure, no significant differences were observed between 10-3/SB and CY/SB. The most effective bonding was obtained with the bonding systems of GLUMA/10-3/SB and GLUMA/CY/SB. Improved outcome is expected with these bonding systems when building up abutment teeth with indirect restorations.


Subject(s)
Dental Bonding/methods , Dentin-Bonding Agents , Glutaral , Iron Compounds , Polymethacrylic Acids , Analysis of Variance , Animals , Cattle , Dental Restoration Failure , Dentin/ultrastructure , Humans , In Vitro Techniques , Methacrylates , Methylmethacrylate , Microscopy, Electron, Scanning , Molar , Polymethyl Methacrylate , Tensile Strength
16.
Pediatr Surg Int ; 18(4): 221-6, 2002 May.
Article in English | MEDLINE | ID: mdl-12021965

ABSTRACT

Persistent pulmonary hypertension (PPH) in congenital diaphragmatic hernia (CDH) lung has been shown to be associated with structural changes in the pulmonary vasculature, including medial and adventitial thickening. Vascular endothelial growth factor (VEGF) is a potent mitogenic and permeability factor targeting predominantly endothelial cells. mRNA encoding VEGF is detected in all fetal tissues and is most abundant in fetal lung, kidney, and liver. Recently, antenatal dexamethasone (Dex) treatment has been shown to prevent pulmonary-artery structural changes in experimentally-produced CDH. The aim of this study was to investigate mRNA and protein levels of VEGF in CDH lung and to determine whether antenatal Dex treatment has any effect on the production of VEGF. A CDH model was induced in pregnant rats following administration of 100 mg nitrofen on days 9.5 of gestation (term=22 days). Dex 0.25 mg/kg was given on day 18.5 and 19.5. Cesarean section was performed on day 21 of gestation. The fetuses were divided into three groups: normal controls (NC, n=8); nitrofen-induced CDH (CDH, n=8); and nitrofen-induced CDH with antenatal Dex treatment (CDH-Dex, n=8). Protein and mRNA were extracted from the whole lung. VEGF protein was measured by ELISA assay and mRNA expression was evaluated by reverse transcription-polymerase chain reaction. Immunohistochemistry using anti-rat VEGF antibody was also performed in each group. VEGF protein as well as mRNA expression were significantly increased in the CDH group compared to the NC group, which was not affected by antenatal Dex treatment. VEGF immunoreactivity in pulmonary vessel walls was increased in the CDH and CDH-Dex groups compared to the NC group. The enhanced VEGF protein and mRNA expression in CDH lung suggests that increased local synthesis of VEGF may be responsible for the structural changes in the pulmonary vasculature in CDH lung. VEGF expression in CDH lung is not downregulated by antenatal Dex treatment.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Dexamethasone/therapeutic use , Hernia, Diaphragmatic/chemically induced , Lung/abnormalities , Lymphokines/drug effects , Phenyl Ethers/adverse effects , Analysis of Variance , Animals , Endothelial Growth Factors , Enzyme-Linked Immunosorbent Assay , Female , Hernia, Diaphragmatic/pathology , Hernias, Diaphragmatic, Congenital , Immunohistochemistry , Rats , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factors
17.
J Oral Rehabil ; 29(5): 478-83, 2002 May.
Article in English | MEDLINE | ID: mdl-12028497

ABSTRACT

The purpose of this study was to evaluate the effects of disinfectants on the bond strength of resin to dentine. The surface of bovine dentine was exposed to formaldehyde (FA) aqueous solutions, glutaraldehyde (GA) aqueous solutions, 2-hydroxyethyl methacrylate aqueous solutions (HEMA), a commercially available dentine primer (Gluma CPS desensitizer, GLUMA), isotonic sodium chloride solution (IS), and distilled water (DW), and placed in a humidor (HU) at 37 degrees C, or non-stored (baseline). All dentine surfaces were conditioned with a 10% citric acid and 3% ferric chloride solution (10-3 liquid), and then bonded to an acrylic rod with a self-curing adhesive resin (Super-Bond C&B). The mean tensile bond strengths determined 24 h after bonding were compared by analysis of variance (ANOVA) and Fisher's protected LSD test (n=5, P < or = 0.05). The exposure of dentine to IS, DW and HU for both 48 and 168 h resulted in a decrease in bond strength when compared with the baseline. The highest bond strengths after 168 h of exposure were obtained with 5% GA, 10% HEMA, and GLUMA, the values of which were equivalent to baseline and were significantly higher than that of FA. It is concluded that disinfectant pre-treatment with 5% GA or GLUMA stabilizes the bonding of tri-n-butylborane (TBB) initiated luting agent to bovine dentine conditioned with 10-3 liquid.


Subject(s)
Boron Compounds/chemistry , Dental Bonding , Dentin-Bonding Agents/chemistry , Dentin/ultrastructure , Disinfectants/chemistry , Glutaral/chemistry , Methacrylates/chemistry , Methylmethacrylates/chemistry , Resin Cements/chemistry , Acid Etching, Dental , Analysis of Variance , Animals , Cattle , Chlorides , Citric Acid/chemistry , Composite Resins/chemistry , Ferric Compounds/chemistry , Formaldehyde/chemistry , Humidity , Isotonic Solutions/chemistry , Sodium Chloride/chemistry , Tensile Strength , Time Factors , Water/chemistry
18.
J Oral Rehabil ; 29(2): 121-6, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11856389

ABSTRACT

The purpose of the present study was to evaluate the surface preparation effects of eight metal conditioners and an adhesive system on bonding between a prosthodontic composite material and cast titanium. Eight primers designed for conditioning base metal alloys (Acryl Bond, All-Bond 2 Primer B, Alloy Primer, Cesead II Opaque Primer, Eye Sight Opaque Primer, Metafast Bonding Liner, Metal Primer II, and MR Bond) as well as a surface modification technique (Siloc) were assessed. Disk specimens cast from titanium (T-Alloy H) were either primed with one of the eight primers or treated with the Siloc system, and then bonded with a light-activated composite material (Artglass). Bond durability was evaluated by thermocycling (4 and 60 degrees C, 1 min each, 20, 000 cycles). After thermocycling, two groups either primed with the Cesead II Opaque Primer material or treated with the Siloc system exhibited significantly greater bond strength (20.0 and 19.0 MPa) than the other groups (0.2-12.6 MPa, P < 0.05). These two systems are considered to be useful for improving bonding between the titanium and the composite material tested.


Subject(s)
Adhesives/chemistry , Composite Resins , Dental Bonding , Dental Veneers , Titanium , Analysis of Variance , Dentin-Bonding Agents/chemistry , Hydrophobic and Hydrophilic Interactions , Materials Testing , Silanes , Statistics, Nonparametric , Surface Properties
19.
Plant Cell Physiol ; 42(10): 1140-8, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11673630

ABSTRACT

High-temperature effects on Photosystem II and plasma membranes, temperature dependence of growth, and acclimation to the growth temperature were studied in a mesophilic cyanobacterium, Synechocystis sp. PCC6803. The following results were obtained. (1) Small but distinct temperature acclimation of the PSII reaction center activity was shown for the first time when the activity was measured at inhibitory high temperatures. However, the reaction center activity showed no apparent acclimation when it was measured at growth temperatures after heat stress. (2) Oxygen-evolving activity and the permeability of plasma membranes showed higher resistance to heat when PCC6803 cells were grown at higher temperatures. (3) Acclimation of photosynthesis to the growth temperature seemed to occur so as to maintain photosynthesis activity not at a maximum level but in a certain range at the growth temperatures. (4) Neither sensitivity to high-temperature-induced dissociation of phycobilisomes from the PSII reaction center complexes nor degradation of phycocyanin were altered by changes in the environmental temperature. (5) A close relationship between the viability of cells and the structural changes of plasma membranes (but not the inactivation of photosynthesis) was observed. The denaturation process of PSII complexes and the relationship between the temperature dependence of the growth of Synechocystis PCC6803 cells and that of the photosynthetic activity are also discussed.


Subject(s)
Cyanobacteria/growth & development , Hot Temperature , Photosynthetic Reaction Center Complex Proteins/metabolism , Cell Membrane/metabolism , Cell Membrane Permeability , Cyanobacteria/metabolism , Fluorescence , Phycobilisomes
20.
Am J Dent ; 14(2): 81-4, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11507804

ABSTRACT

PURPOSE: The purpose of this study was to investigate the wear resistance of prosthodontic luting materials with a titanium framework by means of an in vitro three-bodied wear-testing device. MATERIALS AND METHODS: The surfaces of flat cast titanium disks were blasted with 50 microns alumina. Placing a 50 microns masking tape on the plane surface, the disks were bonded with five luting materials. The axial surfaces of the bonded disks were ground flat with 600 grit silicon-carbide paper, and then cyclically loaded (75.6 N, 1.2 Hz) by a chewing simulator for 400,000 cycles. The distance between titanium and cement surfaces was measured in micrometers by means of a profilometer to determine delta wear, and the surface texture was evaluated with a scanning electron microscope. RESULTS: The delta wear measurement showed that the resistance of Super-Bond Opaque adhesive was significantly higher than Panavia Fluoro adhesive and Fuji I cement after 400,000 wear cycles. No significant differences were detected among Super-Bond Opaque adhesive, Super-Bond adhesive, and All-Bond adhesive. Visually, continuity with the titanium framework was observed when the titanium disks were luted with resin systems.


Subject(s)
Dental Restoration Wear , Resin Cements , Titanium , Analysis of Variance , Materials Testing , Microscopy, Electron, Scanning
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