Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 24
Filter
Add more filters










Publication year range
1.
Int J Oral Maxillofac Surg ; 48(7): 857-864, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30611598

ABSTRACT

The aim of this phase II, multicentre, randomized controlled trial was to evaluate the effectiveness of a comprehensive oral management protocol for the prevention of severe oral mucositis in patients with oral cancer receiving radiotherapy alone or chemoradiotherapy. In total, 124 patients with oral cancer were enrolled from five institutions. Of these, 37 patients undergoing radiotherapy were randomly divided into an intervention group (n=18) and a control group (n=19). The remaining 87 patients, who were undergoing chemoradiotherapy, were also randomized into an intervention group (n=42) and a control group (n=45). During radiotherapy, patients in the control group received only oral care, while those in the intervention group additionally received spacers to cover the entire dentition, pilocarpine hydrochloride, and topical dexamethasone ointment for oral mucositis. The primary endpoint was the incidence of severe oral mucositis. The intervention was significantly associated with a decreased incidence of severe oral mucositis in patients receiving radiotherapy alone (P=0.046), but not in those receiving chemoradiotherapy (P=0.815). These findings suggest that an oral management protocol can prevent severe oral mucositis in patients with oral cancer undergoing radiotherapy without concurrent chemotherapy.


Subject(s)
Head and Neck Neoplasms , Mouth Neoplasms , Stomatitis , Administration, Oral , Chemoradiotherapy , Humans
2.
J Periodontal Res ; 52(1): 114-121, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27028150

ABSTRACT

BACKGROUND AND OBJECTIVE: The association between periodontal disease and nutrient intake was examined using linked data from the 2005 National Health and Nutrition Survey, the Comprehensive Survey of Living Conditions and the Survey of Dental Diseases from the same year 'using linked data from the National Health and Nutrition Survey, the Comprehensive Survey of Living Conditions and the Survey of Dental Diseases, all from 2005'. There has been increasing focus on the importance of nutritional factors in disease in recent years, but very few studies in Japan have looked at the association between periodontal disease and nutrients. Therefore, in the present study we investigated factors associated with periodontal disease, particularly in terms of nutrient intake. MATERIAL AND METHODS: Data from 3043 individuals, ≥ 20 years of age (the original study sample comprised 4873 individuals, but those younger than 20 years of age and pregnant women were excluded from the present study) were compiled from linked responses to these three surveys from the same year. Permission to use the data was obtained from the Lifestyle-Related Diseases Control General Affairs Division of the Ministry of Health, Labor, and Welfare, Japan. Information including basic attributes, family structure, economic status, physical condition, lifestyle habits, diet, dental habits, blood data, intake of foods (including the categories of food) and nutrient-related information were obtained from the linked data. The individual maximum Community Periodontal Index (CPI) was used as an index of periodontal disease. Subjects were divided, according to maximum CPI, into groups in which CPI = 0-2 or CPI = 3-4, and associations between CPI and basic attributes, family structure, economic status, physical condition, lifestyle habits, diet, blood data and food intake were analyzed. RESULTS: Multivariate analysis revealed that the percentage of calories from fat was a nutrient factor associated with periodontal disease, with the percentage of calories from fat being significantly lower in the group with advanced periodontal disease. CONCLUSION: The results suggest that a low-fat, high-carbohydrate diet is related to periodontal disease. A more detailed analysis of this topic will be conducted in the future using different indices of periodontal disease.


Subject(s)
Dietary Fats/adverse effects , Periodontal Diseases/etiology , Adult , Diabetes Complications/epidemiology , Female , Humans , Japan/epidemiology , Life Style , Male , Metabolic Syndrome/complications , Middle Aged , Nutrition Surveys , Nutritional Status , Periodontal Diseases/epidemiology , Risk Factors , Young Adult
3.
JDR Clin Trans Res ; 2(1): 87-92, 2017 Jan.
Article in English | MEDLINE | ID: mdl-30938644

ABSTRACT

The 2004 Japanese National Health and Nutrition Survey collected data on several measures, including self-reported dental health. In addition, this was the first nationwide survey to focus on metabolic syndrome (MetS) in Japan. Therefore, the authors used this nationwide data set to assess the relationship between number of teeth present and MetS. Anonymized data were available with permission from the Ministry of Health, Labour and Welfare of Japan. Data from 3,195 men and women aged 35 to 99 y were examined, and logistic regression analyses were used to evaluate the association between number of teeth and MetS. Moreover, the authors performed an analysis of covariance to compare the mean number of teeth between those with and those without MetS, after adjusting for confounders. In comparison with those having ≥28 teeth, those with fewer remaining teeth demonstrated significantly higher odds of having MetS. Specifically, those having 1 to 9 teeth had higher odds of having MetS than those with more teeth and were more than twice as likely to be affected than those with ≥28 teeth. Furthermore, individuals with MetS in the age groups of 45 to 54, 55 to 64, and 65 to 74 y had significantly fewer teeth than those without MetS in the same age groups. These results suggest that the number of teeth present is associated with the prevalence of MetS in the Japanese population. Knowledge Transfer Statement: The results of this study can be used by clinicians when they examine patients with periodontal disease or extensive tooth loss to refer for a general medical examination.

4.
Community Dent Health ; 28(1): 29-33, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21485231

ABSTRACT

OBJECTIVES: To determine whether children advised by a pediatrician to take sports drinks consume them more frequently than do other children and whether these children have an increased risk of dental caries. METHODS: The subjects were 522 mother/child pairs who attended a dental checkup for 3-year-olds at one of ten community health centers in Nagasaki, Japan. Pearson's chi-square test was used to compare the prevalence of children with or without dental caries according to child-related variables. Multiple logistic regression was performed to assess the relationship between the presence of dental caries and child-related variables taken from a dental checkup and a questionnaire. RESULTS: A high frequency of sports drink consumption was strongly associated with dental caries in children. The highest proportion of mothers answered that they were advised by a pediatrician to give sports drinks to their children. However, these children consumed sports drinks significantly less frequently than did children who did so for reasons other than pediatrician recommendations. In addition, these children were significantly less likely to have dental caries than were children who consumed sports drinks for otherreasons. CONCLUSIONS: Pediatrician-recommended consumption of sports drinks does not lead to more frequent consumption of these beverages or to dental caries in 3-year-old children.


Subject(s)
Beverages/adverse effects , Dental Caries/etiology , Pediatrics , Chi-Square Distribution , Child, Preschool , DMF Index , Dental Caries/epidemiology , Female , Humans , Japan/epidemiology , Logistic Models , Male , Prevalence , Sports , Surveys and Questionnaires
5.
J Phys Condens Matter ; 22(38): 384212, 2010 Sep 29.
Article in English | MEDLINE | ID: mdl-21386546

ABSTRACT

We report a first-principles description for coherent phonon generation in diamond based on the time-dependent density functional theory. The time-dependent Kohn-Sham equation is solved in real time in order to calculate the electron dynamics in periodic solid exposed to an ultrashort laser pulse. We find that the calculated forces acting on ions are consistent with measurements as regards the selection rule and the dependence on the laser intensity.

6.
J Phys Condens Matter ; 21(6): 064222, 2009 Feb 11.
Article in English | MEDLINE | ID: mdl-21715924

ABSTRACT

We have developed a simulation method to describe three-dimensional dynamics of electrons and ions in a molecule based on the time-dependent density-functional theory. We solve the time-dependent Kohn-Sham equation for electrons employing the real-space and real-time method, while the ion dynamics are described in classical mechanics by the Ehrenfest method. For an efficient calculation in massively parallel computers, the code is parallelized dividing the spatial grid points. We apply the method to the Coulomb explosion of the H(2)S molecule under an intense and ultrashort laser pulse and investigate the mechanism of the process.

7.
Gene Ther ; 12(22): 1633-9, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16079887

ABSTRACT

The promoter region of the early-growth response-1(Egr-1) gene has been shown to be activated by external radiation, thus making a selective tumoricidal effect possible. A previous experiment showed that the Egr-1 promoter can be activated by internal radiation using radioisotopes as well as external radiation. Internal radiation using I-131 lipiodol (I-131-Lip) has been established as one of the most useful therapeutic strategies against hepatoma. We herein linked the Egr-1 promoter to the herpes simplex virus-thymidine kinase (HSV-TK) gene, and investigated its efficacy in hepatoma gene therapy in combination with I-131-Lip. A luciferase assay showed the Egr-1-promoter activity to be markedly increased in hepatoma tissue specimens in an I-131-dose-dependent manner, whereas a less than two-fold increase in this activity was observed in other organs. In addition, the radioactivity derived from I-131 was selectively accumulated in the tumor tissue specimens. To examine the efficacy of EgrTK/ganciclovir (GCV) gene therapy in vivo, subcutaneous hepatoma xenografts in nude mice were transfected using a hemagglutinating virus of Japan (HVJ)-liposome vector. Complete tumor regression was observed in all the EgrTK-transfected tumors following combination treatment with I-131-Lip and GCV 42 days after treatment without any side effects (n=8). In contrast, the tumors continued to grow in all control mice (n=10). Furthermore, the serum alpha-fetoprotein levels decreased in the combination therapy group, while they increased in the controls. In conclusion, these data indicate that Egr-1 promoter-based gene therapy combined with internal radiation has a selective effect on hepatoma tumors while also showing an improved in vivo efficacy. This combination therapy might, therefore, be an effective human hepatoma gene therapy, even in advanced multiple cases.


Subject(s)
Carcinoma, Hepatocellular/therapy , Early Growth Response Protein 1/genetics , Genetic Therapy/methods , Genetic Vectors/administration & dosage , Liver Neoplasms/therapy , Promoter Regions, Genetic , Animals , Antiviral Agents/therapeutic use , Carcinoma, Hepatocellular/blood , Carcinoma, Hepatocellular/virology , Combined Modality Therapy , Dose-Response Relationship, Radiation , Early Growth Response Protein 1/analysis , Ganciclovir/therapeutic use , Genetic Engineering , Genetic Vectors/genetics , Humans , Immunohistochemistry/methods , Iodine Radioisotopes/administration & dosage , Iodized Oil , Liver Neoplasms/blood , Liver Neoplasms/virology , Liver Neoplasms, Experimental , Mice , Mice, Nude , Neoplasm Transplantation , Simplexvirus/enzymology , Staining and Labeling , Thymidine Kinase/genetics , Transduction, Genetic , Transplantation, Heterologous , alpha-Fetoproteins/analysis
8.
Gene Ther ; 10(4): 304-13, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12595889

ABSTRACT

A strategy for inducing preferential proliferation of the engrafted hepatocytes over host liver cells should markedly increase the benefit of hepatocyte transplantation for the treatment of liver diseases and ex vivo gene therapy. We hypothesized that preparative hepatic irradiation (HIR) to inhibit host hepatocellular regeneration in combination with the mitotic stimulus of host hepatocellular apoptosis should permit repopulation of the liver by transplanted cells. To test this hypothesis, congeneic normal rat hepatocytes were transplanted into UDP-glucuronosyltransferase (UGT1A1)-deficient jaundiced Gunn rats (a model of Crigler-Najjar syndrome type I), following HIR and adenovirus-mediated FasL gene transfer. Progressive repopulation of the liver by engrafted UGT1A1-proficient hepatocytes over 5 months was demonstrated by the appearance of UGT1A1 protein and enzyme activity in the liver, biliary bilirubin glucuronides secretion, and long-term normalization of serum bilirubin levels. This is the first demonstration of massive hepatic repopulation by transplanted cells by HIR and FasL-induced controlled apoptosis of host liver cells.


Subject(s)
Crigler-Najjar Syndrome/therapy , Genetic Therapy/methods , Hepatocytes/transplantation , Adenoviridae/genetics , Animals , Apoptosis , Bilirubin/metabolism , Crigler-Najjar Syndrome/metabolism , Crigler-Najjar Syndrome/pathology , Fas Ligand Protein , Genetic Vectors/administration & dosage , Genetic Vectors/genetics , Glucuronosyltransferase/deficiency , Liver/metabolism , Liver/pathology , Liver/radiation effects , Male , Membrane Glycoproteins/genetics , Membrane Glycoproteins/metabolism , Models, Animal , Rats , Rats, Gunn , Rats, Wistar , Transduction, Genetic/methods
9.
J Dent ; 29(3): 163-71, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11306157

ABSTRACT

OBJECTIVE: This study evaluated the influence of Carisolv (Medi Team) for resin adhesion to sound human primary and young permanent dentin. METHOD: The buccal surfaces of 64 primary molars and 74 premolars were used. Two adhesive systems and resin composites were used; SD: Super-Bond D Liner DUAL (Sun Medical) and Clearfil Photo Anterior(Kuraray), and FB: Imperva Fluorobond and Lite-Fil IIA (Shofu). Ten groups were prepared. Groups 1-5 were primary dentin and Groups 6-10 were permanent dentin. Groups 1 and 6: Carisolv applied and agitated for 3min, SD was used. Groups 2 and 7: etched with 10-3 solution (Sun Medical) for 10s, SD was used. Groups 3 and 8: treated with Carisolv and then etched, SD was used. Groups 4 and 9: treated with Carisolv, FB was used. Groups 5 and 10: FB was used. The microstructural effects of Carisolv, 10-3 solution and Carisolv plus 10-3 solution applied to dentin were evaluated by SEM. In addition, the microstructure of the resin-dentin interfaces of each group were studied using SEM. Shear bond strengths (SBS) were tested, and the failed surfaces were observed using SEM. Data was statistically analyzed using ANOVA with subsequent application of post hoc Duncan's new multiple range test at p<0.05. RESULTS: The effect of Carisolv on primary dentin was stronger than that to permanent dentin. The mean SBS (unit:MPa) of Groups 1-10 were: 5.6, 15.8, 7.6, 17.5, 13.5, 8.1, 16.2, 18.2, 31.4 and 15.5. The SBS of Group 9 (Carisolv treated permanent dentin) was significantly higher than those of other groups. There was no significant difference of SBS among Groups 2, 4, 5, 7, 8 and 10, Groups 3, 5 and 6, and Groups 1, 3 and 6. SIGNIFICANCE: Carisolv treatment before etching significantly decreased the SBS to primary dentin in SD groups, but significantly increased the SBS to permanent dentin in FB groups.


Subject(s)
Composite Resins/chemistry , Dental Bonding , Dental Cavity Preparation/methods , Dentin-Bonding Agents/chemistry , Glutamic Acid/therapeutic use , Leucine/therapeutic use , Lysine/therapeutic use , Acid Etching, Dental , Analysis of Variance , Bicuspid , Dental Cements/chemistry , Dentin/drug effects , Dentin/ultrastructure , Fluorides, Topical/chemistry , Glutamic Acid/chemistry , Humans , Leucine/chemistry , Lysine/chemistry , Methacrylates/chemistry , Microscopy, Electron, Scanning , Molar , Resin Cements/chemistry , Statistics as Topic , Stress, Mechanical , Surface Properties , Tooth, Deciduous/drug effects , Tooth, Deciduous/ultrastructure
10.
Hum Gene Ther ; 11(18): 2453-63, 2000 Dec 10.
Article in English | MEDLINE | ID: mdl-11119417

ABSTRACT

To investigate the usefulness of heat shock protein (HSP) promoter for breast cancer gene therapy, hyperthermia and HSV thymidine kinase (tk) suicide gene combination therapy was examined with mouse mammary cancer cell line FM3A. HSP promoter activity was markedly increased after heat shock (41-45 degrees C), with maximum activation (about 400-fold) at 3 hr. An in vitro cytotoxic assay showed that HSP-tk-transduced FM3A cells became more sensitive (more than 50,000 times) to ganciclovir (GCV) with heat shock, but untreated cells showed no increased cytotoxic sensitivity to GCV compared with control FM3A cells. In addition to promoter-oriented selective cell killing, a "chemosensitization effect" as a bystander effect was demonstrated by hyperthermia and suicide gene combination therapy, using a non-heat-inducible promoter. Immunohistochemical analysis revealed that this synergistic killing effect was dependent on apoptotic cell death with upregulation of both Fas and FasL (Fas ligand) expression. We also examined the efficacy of HSP-tk gene therapy in vivo by implanting breast cancer in subcutaneous and intraperitoneal models of BALB/c nude mice targeted by the HVJ-anionic liposome method. Significant tumor regression was observed in HSP-tk-transduced tumors followed by hyperthermia therapy, but no such inhibition was noted in either the mock vector transfection or hyperthermia group compared with control tumor-bearing mice. Our results demonstrate that this combination system is synergistically effective in mediating Fas-dependent apoptosis for a specific gene therapy targeting HSP-expressing mammary carcinomas, even in advanced and heat-resistant breast cancer.


Subject(s)
Breast Neoplasms/genetics , Breast Neoplasms/therapy , Genetic Therapy/methods , Heat-Shock Proteins/genetics , Promoter Regions, Genetic , Animals , Antiviral Agents/pharmacology , Apoptosis , Dose-Response Relationship, Drug , Fas Ligand Protein , Female , Ganciclovir/pharmacology , Hot Temperature , Immunohistochemistry , In Situ Nick-End Labeling , Liposomes/metabolism , Mammary Neoplasms, Animal/metabolism , Membrane Glycoproteins/metabolism , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Transplantation , Plasmids/metabolism , Retroviridae/metabolism , Temperature , Thymidine Kinase/metabolism , Time Factors , Tissue Distribution , Transduction, Genetic , Transfection , Tumor Cells, Cultured , Up-Regulation , fas Receptor/metabolism
12.
Artif Organs ; 24(12): 932-8, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11121972

ABSTRACT

Establishment of a bioartificial liver support system using genetically modified hepatocytes is a potential approach to improve the treatment of severe liver failure. We describe the development of an efficient ex vivo method of gene transfer into a large number of porcine hepatocytes using hemagglutinating virus of Japan (HVJ)-liposome. The transfection efficiency of HVJ-liposome into isolated porcine hepatocytes attached to microcarrier beads was evaluated by beta-galactosidase (beta-gal) staining, fluorescence activated cell sorting analysis for beta-gal and luciferase assay, respectively. To examine the function and cellular damage of transduced hepatocytes, we used enzyme-linked immunosorbent assay for porcine albumin synthesis, lidocaine clearance test (P-450 activity), aspartate aminotransferase, and lactic dehydrogenase release assays. The optimal conditions for gene transfer into the beads-attached hepatocytes using HVJ-liposome included 4 microg of deoxyribonucleic acid with 200 microg of lipid/2 x 105 cells and exposure duration of 90 min. Under these conditions, beta-gal and luciferase genes were transduced to 2.5 x 108 isolated porcine hepatocytes following attachment to the beads. Positive beta-gal staining was observed in more than 30% of the beads-attached hepatocytes. The gene transfer activity of HVJ-liposome method determined by luciferase activities was about 100-fold of that of the lipofection method. Transfected porcine hepatocytes remained functional without any significant cell damage. Our results demonstrated that HVJ-liposome mediated gene transfer into microcarrier-attached porcine hepatocytes is an efficient and nontoxic method suitable for a bioartificial liver support sytem.


Subject(s)
Gene Transfer Techniques , Hepatocytes , Liposomes , Liver, Artificial , Respirovirus , Animals , Cells, Cultured , Collagen , Female , Hepatocytes/metabolism , Microspheres , Respirovirus/genetics , Swine , Transduction, Genetic , Transfection , beta-Galactosidase/metabolism
13.
J Bone Miner Res ; 15(10): 1924-34, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11028444

ABSTRACT

The mechanism controlling the disappearance of osteoclasts from bone surfaces after bone resorption in vivo is largely unknown. This is because there is no suitable experimental system to trace the final fate of osteoclasts. Here, we used an experimental model of tooth movement in rats to show that preexisting osteoclasts disappeared from the bone surface through apoptosis during a force-induced rapid shift from bone resorption to formation. On the distal alveolar bone surface of the maxillary molar in growing rats, many mature osteoclasts were present. When light tensional force was applied to the bone surface through an orthodontic appliance, these preexisting osteoclasts gradually disappeared. One day after the application of force, about 24% of the osteoclasts exhibited apoptotic morphology and the proportion of apoptotic cells was increased to 41% by day 2, then decreased afterward. These changes were undetectable on the control distal alveolar bone surface, which is free from tensional force. As shown by in situ hybridization, a marked increase in transforming growth factor beta1 (TGF-beta1) and osteoprotegerin (OPG) messenger RNA (mRNA) was observed in the stretched cells on the tensioned distal bone surface, simultaneously with the loss of osteoclasts. Both of these factors are known to have a negative effect on osteoclast recruitment and survival. As early as 2 days after force application, some of these stretched cells were identified as cuboidal osteoblasts showing intense signals for both factors. Our data suggest there may be a sequential link in tensional force applied on the bone lining cells, up-regulation of TGF-beta1/OPG, and disappearance of osteoclasts.


Subject(s)
Apoptosis , Bone Resorption/metabolism , Glycoproteins/genetics , Lymphotoxin-alpha/genetics , Osteoclasts/cytology , Osteoclasts/metabolism , Receptors, Cytoplasmic and Nuclear/genetics , Acid Phosphatase/metabolism , Animals , Apoptosis/drug effects , Bone Resorption/chemically induced , Carrier Proteins/metabolism , Cathepsin K , Cathepsins/analysis , Cell Count , Cell Survival , Glycoproteins/pharmacology , Histocytochemistry , In Situ Hybridization , In Situ Nick-End Labeling , Isoenzymes/metabolism , Male , Membrane Glycoproteins/metabolism , Osteocalcin/genetics , Osteocalcin/metabolism , Osteoclasts/drug effects , Osteoprotegerin , RANK Ligand , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Wistar , Receptors, Tumor Necrosis Factor , Recombinant Proteins , Stress, Mechanical , Tartrate-Resistant Acid Phosphatase , Tooth/cytology , Tooth/growth & development , Tooth/metabolism
14.
Artif Organs ; 24(4): 265-70, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10816199

ABSTRACT

Recently, bioartificial liver (BAL) treatment was reported to provide beneficial effects for patients with fulminant hepatic failure (FHF). Some success in experimental or clinical trials has been reported; however, the evaluation of BAL efficacy remains unclear, especially in comparison with other treatments for FHF. The purpose of this study was to compare the efficacy between BAL and plasma exchange (PE) in experimentally induced FHF in pigs. Pigs undergoing hepatic devascularization (HD) were placed into the following groups: no treatment (control; n = 6), BAL treatment (BAL; n = 5), and plasma exchange (PE; n = 5). Each treatment was initiated 6 h after HD and lasted for 4 h. BAL treatment significantly improved liver functions in FHF pigs. The decrease in cerebral perfusion pressure was also significantly suppressed in the pigs with BAL, and their survival time was prolonged compared with the results in pigs with PE. The effects of BAL outperform those of PE in the treatment of experimental FHF model.


Subject(s)
Liver Failure/therapy , Liver, Artificial , Plasma Exchange , Analysis of Variance , Animals , Blood Pressure/physiology , Cell Separation , Cerebrovascular Circulation/physiology , Disease Models, Animal , Equipment Design , Female , Follow-Up Studies , Intracranial Pressure/physiology , Liver/cytology , Membranes, Artificial , Polyethylene , Spectrophotometry, Infrared , Survival Rate , Swine
15.
Pediatr Dent ; 22(2): 101-6, 2000.
Article in English | MEDLINE | ID: mdl-10769853

ABSTRACT

PURPOSE: This study compared fluoridated bonding resin adhesion to primary enamel (Group 1), primary dentin (Group 2), permanent enamel (Group 3), and permanent dentin (Group 4). METHODS: The buccal surfaces of 24 primary molars and 24 premolars were used. The bonding system and resin composite used in this study were Imperva Fluorobond and Lite-Fil IIA (Shofu Inc., Kyoto, Japan). Effects of tooth surface conditioning by FB primer were observed using SEM (N = 2/group). Shear bond strengths (SBS) were tested, and the test surfaces of enamel, dentin, and resin specimens were observed using SEM (N = 10/group). Data was statistically analyzed using one-way ANOVA with subsequent post hoc Duncan's new multiple range test at P < 0.05. RESULTS: Effects of tooth surface conditioning by FB primer were appropriate to dentin but low to enamel. Means and standard deviations of the SBS for each group were: Group 1 (16.34, 5.53 MPa), Group 2 (15.06, 7.02 MPa), Group 3 (14.39, 6.52 MPa) and Group 4 (15.45, 5.35 MPa). There was no significant difference of SBS among Groups 1, 2, 3, and 4. CONCLUSION: Imperva Fluorobond system gave the same level of bond strength to primary enamel, primary dentin, permanent enamel, and permanent dentin.


Subject(s)
Composite Resins , Dental Bonding , Dental Cements , Fluorides, Topical , Acid Etching, Dental , Analysis of Variance , Dental Enamel , Dentin , Dentition, Permanent , Humans , Materials Testing , Random Allocation , Statistics, Nonparametric , Tensile Strength , Tooth, Deciduous
16.
ASAIO J ; 46(1): 56-9, 2000.
Article in English | MEDLINE | ID: mdl-10667717

ABSTRACT

A porcine hepatocyte based bioartificial liver (BAL) is still insufficient to replace liver transplantation. In this experiment, to strengthen the performance of a BAL, the effect of human recombinant hepatocyte growth factor (rhHGF) on the proliferation and function of xenogeneic porcine hepatocytes was studied. Isolated porcine hepatocytes were seeded at various densities (5 x 10(3) to 8 x 10(4) cells/well) on a collagen coated 96 well plate in Dulbecco's modified Eagle's medium (DMEM) with 10% FCS. After 4 hours, the medium was changed to DMEM with added insulin and dexamethasone. Subsequently, rhHGF was added at various concentrations (0, 0.625, 1.25, 2.5, 5, 10, 20, 40 ng/ml) and cultured for an additional 24, 48, and 72 hours, respectively. The proliferation of porcine hepatocytes in response to rhHGF reached a plateau at 2.5 ng/ml at 24 hours and subsequently decreased. The levels of porcine albumin vs protein present in the supernatant increased when cultured at high cell density. In conclusion, rhHGF was found to stimulate proliferation of porcine hepatocytes at low cell density and low concentration. rhHGF can also increase albumin synthesis at higher cell density, thus indicating its potential use in a more satisfactory porcine hepatocyte based BAL.


Subject(s)
Hepatocyte Growth Factor/pharmacology , Liver/drug effects , Albumins/biosynthesis , Animals , Cell Division/drug effects , DNA/biosynthesis , Humans , Liver/cytology , Liver/metabolism , Recombinant Proteins/pharmacology , Swine
17.
Int J Artif Organs ; 22(7): 505-10, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10493559

ABSTRACT

Our bioartificial liver (BAL) consists of porcine hepatocytes attached to beads and plasma perfused through the system. The function of our BAL lasts for approximately 7 hours. The objective of the present study was to investigate the efficacy of Nafamostat Mesilate (NM), a protease inhibitor and potent complement inhibitor, for improving the performance of the BAL. The experimental groups were divided as follows; the NM group (n=7) where the BAL had porcine hepatocytes with 3.8x10(-4) M, of NM, and the control group where the BAL had no NM. Plasma obtained from patients suffering from hepatic failure was perfused through the BAL for 10 hours. The viability of the porcine hepatocytes and the levels of alanine aminotransferase (ALT) in the human plasma were measured during perfusion. After the 10-hour perfusion, another human hepatic failure plasma was perfused for an additional 1 hour and then the function of the BAL was evaluated. After the 10-hour perfusion, the viability of the hepatocytes in the NM group was 51 +/- 7%, whereas that in the control group was rapidly reduced by 35 +/- 5%. Although the levels of ALT in the human plasma in both groups increased with the perfusion time, those in the NM group were significantly lower than those in the control group (p < 0.05). These results suggest that NM prevented damage to the porcine hepatocytes in human hepatic failure plasma as compared to the control group. In the human hepatic failure plasma before perfusion, the partial thrombin time (PT) and the plasma ammonia (NH3) levels were 19.8 +/- 12% and 288 +/- 102 microg/dl, respectively. Fischer's ratios were 0.98 +/- 0.39. Even after the 10-hour perfusion, the BAL in the NM group significantly improved the levels of PT (38 +/- 10%; p < 0.05), NH3 (214 +/- 34 microg/dl; p < 0.05) and Fischer's ratios (1.4 +/- 0.3; p < 0.05). On the other hand, the BAL in the control group did not show any improvement in those parameters. In conclusion, NM was found to help in maintaining the viability of porcine hepatocytes in human hepatic failure plasma, thereby allowing the porcine hepatocyte-based BAL to function much better.


Subject(s)
Complement Inactivator Proteins/pharmacology , Guanidines/pharmacology , Liver, Artificial , Liver/cytology , Liver/drug effects , Protease Inhibitors/pharmacology , Alanine Transaminase/blood , Ammonia/blood , Animals , Benzamidines , Cell Survival , Female , Humans , In Vitro Techniques , Liver Failure/blood , Liver Failure/therapy , Swine , Thrombin Time
18.
Int J Artif Organs ; 22(5): 329-33, 1999 May.
Article in English | MEDLINE | ID: mdl-10467932

ABSTRACT

For the clinical treatment with porcine hepatocyte-based bioartificial liver (BAL), the use of an anticoagulant in the extracorporeal system is essential. In this experiment, we studied the effect of various anticoagulants on cultured porcine hepatocytes. Porcine hepatocytes were isolated and seeded at a density of 2 x 10(5) cells on a collagen-coated plate in Dulbecco's modified Eagle's medium (DMEM) with 10% fetal calf serum (FCS). Twenty-four hours later, the medium was changed to DMEM with various anticoagulants such as nafamostat mesilate (NM), sodium heparin (SH) and sodium citrate (SC) at concentration used clinically. As a control, the hepatocytes were cultured in only DMEM. After culturing for 6 hours, the viability of the porcine hepatocytes, lactate dehydrogenase (LDH) release, lidocaine clearance (cytochrome p450 function) and albumin synthesis were investigated. SC did not affect either the viability or the p450 function of the hepatocytes. In the NM group, the viability of porcine hepatocytes and lidocaine clearance were decreased significantly more than in the other groups. SH did not affect the viability of porcine hepatocytes, however, it seemed to reduce the p450 function. In conclusion, SC may therefore be the optimal anticoagulant available for hepatocyte-based BAL circuit in terms of its cell toxicity.


Subject(s)
Anticoagulants/pharmacology , Liver, Artificial , Liver/drug effects , Albumins/biosynthesis , Animals , Benzamidines , Cell Survival/drug effects , Cells, Cultured , Citrates/pharmacology , Cytochrome P-450 Enzyme System/metabolism , Female , Guanidines/pharmacology , Heparin/pharmacology , In Vitro Techniques , L-Lactate Dehydrogenase/metabolism , Lidocaine/metabolism , Liver/cytology , Liver/metabolism , Sodium Citrate , Swine
19.
Cell Transplant ; 8(4): 419-25, 1999.
Article in English | MEDLINE | ID: mdl-10478723

ABSTRACT

Nafamostat mesilate (NM), a protease inhibitor, possesses a cytoprotective effect and inhibits the activation of complement. The present study investigated whether NM has any protective effect against injury of porcine hepatocytes by human plasma in a bioartificial liver support system. Porcine hepatocytes were harvested and seeded at a density of 2 x 10(5) cells on a 35-mm collagen-coated plate in Dulbecco's modified Eagle's medium (DMEM) with 10% fetal calf serum. Twenty-four hours later, the medium was replaced with human plasma with three concentrations of NM between 3.8 x 10(-5) and 3.8 x 10(-4) M and then cultured for 6 h. The viability of porcine hepatocytes, lactate dehydrogenase (LDH) levels, lidocaine clearance, porcine albumin production, and changes in complement (C3) levels were measured. The viability of porcine hepatocytes in human plasma decreased significantly to 37.7 +/- 11.4% of that in DMEM. NM improved the viability of the hepatocytes, lowered the levels of LDH, and increased lidocaine clearance and albumin production in a concentration-dependent manner. The concentrations of C3, the marker of xenogeneic reactions, did not change significantly, indicating that no hyperacute xenogeneic reaction occurred in our series. Together, our results suggested that NM exerts favorable effects on porcine hepatocytes in human plasma through direct effect such as prevention of protease activity in the plasma membrane of porcine hepatocytes rather than inhibition of complement-dependent immunoreactions.


Subject(s)
Blood Proteins/adverse effects , Guanidines/pharmacology , Liver, Artificial , Liver/cytology , Protease Inhibitors/pharmacology , Albumins/biosynthesis , Anesthetics, Local/pharmacokinetics , Animals , Benzamidines , Cell Survival/drug effects , Cell Transplantation , Cells, Cultured , Complement C3/analysis , Complement C3/pharmacology , Female , Humans , L-Lactate Dehydrogenase/analysis , Lidocaine/pharmacokinetics , Liver/enzymology , Swine , Transplantation, Heterologous
SELECTION OF CITATIONS
SEARCH DETAIL
...