Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “modified”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

Bond strengths of polyacid-modified resin composites and a resin-modified glass-ionomer cement to primary dentin.

PURPOSE: To evaluate the bond strengths of three polyacid-modified resin composites and one resin-modified glass-ionomer cement to caries-simulated primary dentin after 18-months' water immersion. METHODS: Dyract AP, Compoglass F, F2000 and Vitremer were used as test materials. Standardized preparations cavities with a C-factor of 5 were prepared in primary molars. Half of the cavities were stored in a demineralizing media for 7 days to simulate caries-affected dentin. Thereafter, all preparations were restored with the test materials, after which the specimens were stored in water for 18 months, changing the water every week. The specimens were subjected to a microtensile test and all bond strength data (in MPa) were statistically analyzed using one-way analysis of variance (ANOVA) and Tukey HSD tests at P < 0.01. RESULTS: The mean microtensile bond strength to normal primary dentin specimens were 11.2 +/- 1.5 (Dyract AP), 10.6 +/- 2.1 (Compoglass F), 10.8 +/- 1.1 (F2000) and 7.3 +/- 1.6 (Vitremer), while those to the caries-simulated dentin were 4.1 +/- 0.7 (Dyract AP), 3.0 +/- 0.6 (Compoglass F), 2.3 +/- 0.9 (F2000) and 1.9 +/- 0.5 (Vitremer). SEM evaluation of the unfractured specimens revealed evidence of gap formation in the adhesive interface in all samples.

Analysis of Variance↗

Five-year double-blind randomized clinical evaluation of a resin-modified glass ionomer and a polyacid-modified resin in noncarious cervical lesions.

PURPOSE: The aim of this double-blind randomized study was to compare the clinical performance of a resin-modified glass ionomer (Vitremer, 3M) and a polyacid-modified resin (Dyract, Dentsply DeTrey) in noncarious Class V restorations after 5 years. MATERIALS AND METHODS: Twelve patients, having at least one pair of equal-sized noncarious cervical lesions under occlusion and a mean age of 40 years (range 19 to 63 years; median 41), were enrolled in this study. A total of 32 restorations (16 with each material) were placed according to the manufacturers' instructions by two calibrated operators. Two other independent examiners evaluated the restorations at baseline and after 5 years according to the USPHS criteria. The assessment criteria were: retention, anatomical form, marginal adaptation and marginal discoloration, color match, surface texture, and secondary caries. Statistical analysis was conducted using Fisher's exact test (alpha = 0.05). RESULTS: No secondary caries was detected with either material. The retention rate for Vitremer (93%) and for Dyract (78.5%) did not differ significantly (p > 0.05). Regarding anatomical form, only two restorations of each material were recorded as bravo. In terms of marginal adaptation, 38.5% of Dyract restorations were rated alpha and 61.5% bravo, while 84.6% of Vitremer restorations were rated alpha and only 15.4% bravo (p < 0.05). For marginal discoloration, 18.2% of Dyract restorations and 84.6% of Vitremer restorations were rated alpha, with the remaining rated bravo. 86% of Vitremer restorations were rated as bravo and 23% alpha for both surface texture and color match. All Dyract restorations were classified as alpha regarding surface texture, and only two Dyract restorations (18.2%) were classified as bravo in the color match item. CONCLUSION: The marginal adaptation of the RMGIC (Vitremer) was significantly better, the marginal discoloration lower, and the retention rate higher (though not significantly) than that of the PMRC (Dyract) after 5 years in situ. Dyract performed better in terms of surface texture and color match in noncarious Class V restorations after 5 years.

Adult↗

Surface hardness properties of resin-modified glass ionomer cements and polyacid-modified composite resins.

In this study the top and bottom surface hardness of two polyacid-modified composite resins (PMCRs), one resin-modified glass ionomer cement (RMGIC), and one composite resin were evaluated. The affect of water storage on their hardness was also investigated. The study was conducted using four different groups, each having five specimens obtained from fiberglass die molds with a diameter of 5 mm and a height of 2 mm. Measurements were made on the top and bottom surface of each specimen and recorded after 24 hours and again at 60 days. All tested materials showed different hardness values, and the values of top surfaces of the specimens were found to be higher than the bottom surface in all test groups. There was no statistical difference in the Vickers hardness (HV) values when the test specimens were kept in water storage. In conclusion Hytac displayed microhardness values higher than Vitremer and Dyract. We found the order of HV values to be Surfil > Hytac > Dyract > Vitremer, respectively. Vitremer presented the lowest microhardness level and Surfil the highest.

Analysis of Variance↗

Distalization of maxillary molars with Modified Greenfield Appliance and Modified Nance Appliance as applied to specific case.

This article describes an efficient method for distalizing maxillary molars using fixed intra-arch Nickel Titanium open coil spring loaded appliance--the Modified Greenfield Appliance. After adequate space has been created, the Modified Nance Anchorage Appliance is cemented to prevent any loss of the gained space. The author's Case Study guides the reader step by step to a successful result of the difficult orthodontic case.

Adolescent↗

Comparison of cold flush perfusion with modified blood versus modified Euro-Collins solution for lung preservation.

Single flush perfusion of the lung represents one concept of pulmonary preservation that has provided satisfactory results in both experimental and clinical situations. The technique has allowed successful distant organ procurement, with consequent enlargement of the available donor pool. Both cold modified blood (CMB) and modified Euro-Collins solution (ECS) are currently used as perfusates, although the volumes of each used clinically are different. CMB is administered at 20 ml/kg and ECS at 60 ml/kg. Both techniques combine the use of a prostaglandin to enhance preservation. In this study these two perfusion techniques were compared in a canine model of unilateral left lung allotransplantation after 6 hours of storage, with subsequent ligation of the recipient's contralateral pulmonary artery and bronchus. Equal volumes of both solutions were used (20 ml/kg) to determine whether the blood vehicle was necessary to provide good preservation at this volume. Assessment of pulmonary preservation was determined by animal survival, blood gas analyses, hemodynamic values, and measurement of lung water content. All animals survived the 24-hour experimental period in stable condition. Postoperative oxygenation was well maintained at control values throughout this period with no significant difference between groups. The pulmonary vascular resistance index was significantly higher in the CMB group at 1 hour (p less than 0.05). Lung compliance, assessed by peak-inspiratory pressure, was impaired to a greater extent in the CMB group than in the ECS animals (p less than 0.01 at 12 and 24 hours).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Differences in the metabolism of oxidatively modified low density lipoprotein and acetylated low density lipoprotein by human endothelial cells: inhibition of cholesterol esterification by oxidatively modified low density lipoprotein.

The rate of degradation of oxidatively modified low density lipoprotein (Ox-LDL) by human endothelial cells was similar to that of unmodified low density lipoprotein (LDL), and was approximately 2-fold greater than the rate of degradation of acetylated LDL (Ac-LDL). While LDL and Ac-LDL both stimulated cholesterol esterification in endothelial cells, Ox-LDL inhibited cholesterol esterification by 34%, demonstrating a dissociation between the degradation of Ox-LDL and its ability to stimulate cholesterol esterification. Further, while LDL and Ac-LDL resulted in a 5- and 15-fold increase in cholesteryl ester accumulation, respectively, Ox-LDL caused only a 1.3-fold increase in cholesteryl ester mass. These differences could be accounted for, in part, by the reduced cholesteryl ester content of Ox-LDL. However, when endothelial cells were incubated with Ac-LDL in the presence and absence of Ox-LDL, Ox-LDL led to a dose-dependent inhibition of cholesterol esterification without affecting the degradation of Ac-LDL. This inhibitory effect of Ox-LDL on cholesteryl ester synthesis was also manifest in normal human skin fibroblasts incubated with LDL and in LDL-receptor-negative fibroblasts incubated with unesterified cholesterol to stimulate cholesterol esterification. Further, the lipid extract from Ox-LDL inhibited cholesterol esterification in LDL-receptor negative fibroblasts. These findings suggest that the inhibition of cholesterol esterification by oxidized LDL is independent of the LDL and scavenger receptors and may be a result of translocation of a lipid component of oxidatively modified LDL across the cell membrane.

Acetylation↗

T cell-mediated cytotoxicity against trinitrophenyl-modified cells: effect of glutaraldehyde treatment on the immunogenicity and antigenicity of trinitrophenyl-modified cells.

Cells treated with low concentrations of glutaraldehyde for a 10-sec interval were unable to incorporate 3H-leucine into TCA precipitable protein, respond to H-2 allogeneic cells in mixed lymphocyte reactions (MLR) and cell-mediated lympholysis (CML) assays, or display capping of cell surface immunoglobulin (Ig) with a fluoresceinated anti-Ig reagent. Such cells could stimulate and specifically block H-2 allogeneic CML activity but could not stimulate an H-2 allogeneic MLR response. Trinitrobenzenesulfonic acid (TNBS) treated spleen cells were used to sensitize syngeneic splenocytes into displaying a cytotoxic effect against trinitrophenyl (TNP)-modified target cells. Treatment of the stimulator cells with glutaraldehyde immediately after modification with TNBS did not impair their immunogenic activity. Similar treatment of TNP-modified concanavalin A-stimulated lymphoblasts that were used as inhibitors in a CML cold target competition assay allowed such cells to retain their antigenicity. Cells treated with glutaraldehyde before TNP-modification, however, were not antigenic in the cold target competition assay. These data are compatible with TNBS acting on plasma membrane molecules directly to cause cells to be antigenic and immunogenic in the CML assay rather than affecting internal cellular components.

Aldehydes↗

Usefulness of the Thai modified functional living index--cancer (T-FLIC) and the Thai modified quality of life index (T-QLI) for advanced non-small cell lung cancer.

Serial assessment of Karnofsky performance status (KPS), the Thai modified Functional Living Index Cancer (T-FLIC) and the Thai modified Quality of Life Index (T-QLI) have been used to estimate the quality of life of advanced non-small cell lung cancer patients. This is a prospective randomized trial of best supportive care (BSC) versus best supportive care plus combination chemotherapy given to patients with Stage III b or IV, ECOG 0-1 or 2. There was a good correlation between Karnofsky performance status (KPS) and T-FLIC scores, between T-FLIC and T-QLI scores as the study began. Thus the T-FLIC and T-QLI were useful instruments for the quality of life assessment in Thai patients.

Adult↗

[Interaction of RNAase H from E. coli with modified hybrid duplexes. I. Duplexes modified at the carbohydrate residue].

The influence of oligodeoxyribonucleotide probes containing 1-(D-beta-2'-deoxythreo-pentofuranosyl)thymine or 1-(D-beta-2'-deoxy-2'-fluoro-pentofuranosyl)uracil on the ability of the hybrid duplexes to interact with RNase H from E. coli was studied. A kinetic approach was used to measure of the modification effect. The hybrid duplex, prA18/d(TTflU)6TT, was shown not to interact with RNase H, whereas prA18/d(xTTT)6 inhibited the RNase H activity (Ki = 0.67 mkM). The thermostability of the modified duplexes was estimated. The present technique may lead to the use of some modified oligonucleotides as antisences.

Base Sequence↗

Bond strengths of resin-modified glass ionomers and polyacid-modified resin composites to dentin.

PURPOSE: To measure the shear bond strength of two resin-modified glass ionomers (Vitremer and Fuji II LC) and two polyacid-modified resin composites (Compoglass and Dyract) when applied to dry dentin, dentin supplied with water pressure from the pulp, and after thermocycling. MATERIALS AND METHODS: Ninety six extracted third molars were used. The root portion was removed just below the cemento-enamel junction and the occlusal enamel was removed from the crown segment. An artificial root portion was made in Plexiglas, cemented to the crown segment and connected to a 36 cm. height water column. The tested materials were applied to the surface of dry dentin, dentin supplied with water pressure from the pulp, and after thermocycling. Shear bond strength was measured for the bonded specimens using an Instron at a crosshead speed of 0.5 mm/minute. RESULTS: There were no significant differences in bond strengths between Fuji II LC, Compoglass, and Dyract, which were significantly greater than that of Vitremer. The bond strengths of all materials were slightly increased or not affected by the presence of water pressure from the pulp. After thermocycling, the bond strengths of Fuji II LC, Compoglass, and Dyract were not significantly affected whereas those of Vitremer were significantly decreased.

Analysis of Variance↗

Construction of transgenic pea lines with modified expression of diamine oxidase and modified nodulation responses with exogenous putrescine.

Diamine oxidase (DAO) might influence pea nodule development either by regulating the peroxide-driven cross-linking of glycoproteins in the infection thread matrix or by modifying the metabolism of diamines and polyamines in host cells. Transformed lines of pea (Pisum sativum) with the coding sequence for DAO (PSAO-1) in sense orientation behind a tissue-specific promoter (pENOD12A) showed strong co-suppression of DAO activity in extracts from nodules and epicotyls, whereas the antisense constructs were relatively unaffected. No difference in nodule number was observed between transformed lines and controls, suggesting that DAO does not normally have an essential role in nodule initiation. However, lines showing co-suppression of DAO were less sensitive to the inhibitory effects of exogenous putrescine and less active in the cross-linking of matrix glycoprotein, indicating that putrescine-derived products of DAO activity could retard nodule development. Inoculation of co-suppressed lines with Rhizobium strain B661 (a lipopolysaccharide-defective mutant) resulted in more extreme impairment of nodule development and nitrogen fixation capacity, relative to lines with normal levels of DAO, which suggests that DAO may serve to reduce the endogenous level of inhibitory diamines or polyamines in nodules under physiological stress. We conclude that the most critical role of DAO in pea nodule development is apparently in the regulation of diamine levels in host tissues.

Amine Oxidase (Copper-Containing)↗

Quantification of the 35S promoter in DNA extracts from genetically modified organisms using real-time polymerase chain reaction and specificity assessment on various genetically modified organisms, part I: operating procedure.

A highly sensitive quantitative real-time assay targeted on the 35S promoter of a commercial genetically modified organism (GMO) was characterized (sF/sR primers) and developed for an ABI Prism 7700 Sequence Detection System and TaqMan chemistry. The specificity assessment and performance criteria of sF/sR assay were compared to other P35S-targeted published assays. sF/sR primers amplified a 79 base pair DNA sequence located in a part of P35S that is highly conserved among many caulimovirus strains, i.e., this consensus part of CaMV P35S is likely to be present in many GM events. According to the experimental conditions, the absolute limit of detection for Bt176 corn was estimated between 0.2 and 2 copies of equivalent genome (CEG). The limit of quantification was reached below 0.1% Bt176 content. A Cauliflower Mosaic Virus control (CaMV) qualitative assay targeted on the ORF III of the viral genome was also used as a control (primers 3F/3R) to assess the presence of CaMV in plant-derived products. The specificity of this test was assessed on various CaMV strains, including the Figwort Mosaic Virus (FMV) and solanaceous CaMV strains. Considering the performance of sF/sR quantification test, the highly conserved sequence, and the small size of the amplicon, this assay was tested in a collaborative study in order to be proposed as an international standard.

DNA Primers↗

Postoperative active specific immunization in colorectal cancer patients with virus-modified autologous tumor-cell vaccine. First clinical results with tumor-cell vaccines modified with live but avirulent Newcastle disease virus.

Sixteen patients with colorectal carcinoma Dukes' Stage B2, C, or D were treated with an autologous virus-modified tumor-cell vaccine after potential curative tumor resection (R0-Resection). An inoculum of 1 X 10(7) cells incubated with 32 hemagglutination units of nonirradiated Newcastle disease virus (NDV) was given intracutaneously up to four times at 10-day intervals. The delayed-type hypersensitivity (DTH) skin reaction was measured. The vaccination was well tolerated. In 11 of 16 patients an increasing reactivity against the vaccine was observed during the vaccination procedure. A challenge test using autologous tumor cells without NDV after the vaccination cycle revealed a specific antitumor sensibilization in 12 patients. The DTH response was not due to bacterial contamination or sensibility to the virus. Histologic examination of the vaccination site showed a dense infiltration of predominantly helper T-lymphocytes. We conclude that in most of the patients treated active, specific immunization led to a specific antitumor sensitivity.

Adult↗

T-cell responses induced by the parenteral injection of antigen-modified syngeneic cells. III. Dissociation of primed cytolytic T-cell and efferent suppressor-T-cell activity following intravenous injection of trinitrophenol-modified syngeneic spleen cells.

The parenteral injection of ligand-coupled syngeneic spleen cells has profound effects on immune responsiveness. In this regard, it was examined whether the primed in vitro trinitrophenol (TNP)-specific cytotoxic T-lymphocyte (CTL) responses observed in splenic T-cell populations from mice injected intravenously (iv) with syngeneic TNP-modified spleen cells (TNP-SC) are related to the efferent-acting suppressor-T-cell (Ts) activity observed in splenocytes from iv primed mice. Treatment of mice with cyclophosphamide, adult thymectomy, or monoclonal anti-I-J antiserum prior to the iv injection of TNP-SC was found to eliminate the ability of splenic Ts from these mice to suppress the passive transfer of delayed-type hypersensitivity (DTH) mediated by trinitrochlorobenzene-immune T cells. In contrast, spleen cells from these pretreated mice showed no impairment in the development of augmented TNP-specific CTL responses upon in vitro restimulation with TNP-SC. Separation of the two activities was also achieved in a kinetic analysis. It is concluded that specific enhancement of CTL responsiveness induced by the iv injection of TNP-SC is related to the expansion of a population prelytic Lyt 2+ CTL effector cells which does not appear to contain efferent-acting Lyt 2+ Ts active in suppressing DTH expression.

Animals↗

Induction by chemically modified actin derivatives of antibody specificity. A relation between modified sites and antibody interactions with monomeric and filamentous actins.

A comparison of specific antibodies induced by unfolded actins modified either by oxidation or by arylation of lysine residues was reported. We have focused our work on binding properties with filamentous actin and located its preferential antigenic sites for the anti-arylated-actin antibodies in the C-part of the molecule. An interference of anti-oxidized actin antibodies upon actin polymerisation has also been reported.

Actins↗

Single-strand and double-strand cleavage at half-modified and fully modified recognition sites for the restriction nucleases Sau3a and Taqi.

The influence of cytosine methylation on the cleavage of DNA by the restriction nucleases Sau3A and TaqI has been investigated. Bovine satellite DNA fragments containing a GATCGA sequence, i.e. a Sau3A site overlapping with a TaqI site have been used in this study. The methylation of these fragments has been determined by sequence analysis. It has been found that a TaqI site (TCGA) methylated at cytosine in both DNA strands is still sensitive to double-strand cleavage. A Sau3A site (GATC), however, is rendered resistant to double-strand cleavage by methylation of a single cytosine. Fragments containing the "half-modified" Sau3A site are nicked in the unmethylated DNA strand. It has been shown by sequence analysis of nicked DNA that the single-strand break occurs at the same position which is cleaved in unmodified DNA.

Animals↗

A new medium-term rat colon bioassay applying neoplastic lesions as endpoints for detection of carcinogenesis modifiers-validation with known modifiers.

We have established a medium-term colorectal carcinogenesis rat model initiated with 1,2-dimethylhydrazine (DMH) followed by dextran sodium sulfate (DSS) treatment, featuring induction of neoplastic lesions within 10 weeks. In the present study, we examined its ability to detect modification of colon lesion development with 10- or 20-week experimental periods. F344 male rats were given three subcutaneous injections of DMH (40 mg/kg b.w.) in a week followed by free access to drinking water containing 1% DSS for a week. One week after this regimen, basal diet alone, basal diet containing 0.04% nimesulide or 2% lactoferrin as known inhibitors, 0.3% deoxycholic acid (DCA) as a promoter or 1.5% 1-hydroxyanthraquinone (1-HA) as a carcinogen were supplied. At week 10, the incidence and multiplicity of combined adenomas and adenocarcinomas were significantly (P < 0.05 or 0.01) decreased by nimesulide and lactoferrin, and values for adenomas were significantly (P < 0.01) increased in the 1-HA group. There was no clear change in the DCA group. At week 20, multiplicity and volume of the tumors were significantly (P < 0.01 or 0.05) decreased by nimesulide, but no effect was now evident with lactoferrin. Multiplicity and volume of tumors were significantly (P < 0.01) increased in 1-HA group and a similar tendency was apparent (P = 0.08) with DCA. It is concluded that this system offers a useful tool for detection of colorectal carcinogenesis modifiers within 10-20 weeks, pending further studies for verification employing other model chemicals.

1,2-Dimethylhydrazine↗