Biomedical subjects

M Redlich

Publications and source records attributed to M Redlich.

At least 19 recordsLinked to original sources

PubMed2005

Proteomic analysis of protein components in periodontal ligament fibroblasts.

BACKGROUND: Characterization of periodontal ligament (PDL) fibroblast proteome is an important tool for understanding PDL physiology and regulation and for identifying disease-related protein markers. PDL fibroblast protein expression has been studied using immunological methods, although limited to previously identified proteins for which specific antibodies are available. METHODS: We applied proteomic analysis coupled with mass spectrometry and database knowledge to human PDL fibroblasts. RESULTS: We detected 900 spots and identified 117 protein spots originating in 74 different genes. In addition to scaffold cytoskeletal proteins, e.g., actin, tubulin, and vimentin, we identified proteins implicated with cellular motility and membrane trafficking, chaparonine, stress and folding proteins, metabolic enzymes, proteins associated with detoxification and membrane activity, biodegradative metabolism, translation and transduction, extracellular proteins, and cell cycle regulation proteins. CONCLUSIONS: Most of these identified proteins are closely related to the extensive PDL fibroblasts' functions and homeostasis. Our PDL fibroblast proteome map can serve as a reference map for future clinical studies as well as basic research.

Adolescent↗

PubMed2004

Pressure simulation of orthodontic force in osteoblasts: a pilot study.

OBJECTIVES: To elucidate the RUNX2 gene expression induction in human osteoblasts after mechanical loading. DESIGN: Using a stringent pulse-chase protocol human osteoblasts were exposed to centrifugal pressure force for 30 and 90 min. Untreated control cells were processed in parallel. Before, and at defined times after centrifugation, total RNA was isolated. RUNX2 gene expression was measured using real-time quantitative reverse transcriptase polymerase chain reaction. The stress/control ratio was used to illustrate possible stimulatory or diminishing effects of force application. RESULTS: Immediately after 30 min of force application the RUNX2 gene expression was induced by a factor of 1.7 +/- 0.14 as compared with the negative control. This induction decreased rapidly and reached its pre-load levels within 30 min. Longer force applications (up to 90 min) did not change the RUNX2 gene expression. CONCLUSION: In mature osteoblasts centrifugal pressure force stimulates RUNX2 gene expression within a narrow time frame: loading of mature cells results in a temporary increase of RUNX2 expression and a fast downregulation back to its pre-load expression level. With this pilot study the gene expression behavior after mechanical stimuli could be determined with a simple laboratory setup.

Cells, Cultured↗

PubMed2004

Histopathologic changes in dental and oral soft tissues in 2-butoxyethanol-induced hemolysis and thrombosis in rats*.

BACKGROUND: 2-Butoxyethanol (2-BE; ethylene glycol monobutyl ether) is extensively used as a solvent in surface coatings, such as lacquers, enamels, and varnishes in industrial and household cleaning products. Its major toxicity is manifested in the circulation, as it induces hemolytic anemia and thrombosis in various organs. While 2-BE has been implicated in the induction of anemia in different species, the rat has proven most sensitive, especially the female of this species. The purpose of this study was to document the effects of 2-BE on dentition, the periodontal ligament, the tongue, the salivary glands, and the oral mucosa in male and female Fischer 344 rats. METHODS: The experiment included 40 rats divided into five groups. Four groups were exposed to 2, 3, or 4 daily doses of 2-BE, and a fifth group served as control. The rats were killed on days 2, 3, 4, and 29. The teeth and soft oral tissues were prepared for histopathologic observation. RESULTS: The histopathologic analysis showed that the major effect of 2-BE was exerted on the odontoblasts of the incisors and on molars, with greater effect on the incisors. Foci of damaged muscle cells in the tongue were also observed. The blood vessels were dilated and congested, and a primary thrombosis was seen in the dental pulp. CONCLUSIONS: The results of this study revealed a resemblance between the dental injuries in this rat model and those seen in sickle cell anemia in humans. This 2-BE animal model holds potential to assist in the discovery of preventive measures and/or treatment for dental injuries that occur in human diseases with hemolytic anemia.

Anemia, Hemolytic↗

PubMed2004

The effect of centrifugal force on mRNA levels of collagenase, collagen type-I, tissue inhibitors of metalloproteinases and beta-actin in cultured human periodontal ligament fibroblasts.

BACKGROUND: The aim of orthodontic treatment is to relocate teeth abnormally positioned in the jaws. This is achieved by application of continuous force on the tooth, which is immediately being sensed by the periodontal ligament (PDL), bone and the gingiva. Since the bony response is mediated by the PDL, tooth movement is primarily a PDL phenomenon. OBJECTIVES: Thus, the purpose of the present study was to evaluate the direct effect of force (excluding the in vivo tissue response) on the molecular level of matrix metalloproteinase-1 (MMP-1) and collagen type-I (Col-I) in human PDL fibroblasts. METHODS: PDL cell culture flasks were centrifuged for 10, 20, 30, 60, 90 and 120 min by horizontal microplate rotor. The effect of force on mRNA levels of beta-actin, MMP-1, Col-I, tissue inhibitors-1 and -2 (TIMPs) genes was analyzed by RT-PCR. RESULTS: The results showed that force had no effect on the mRNA levels of beta-actin during the first 90 min of application of force, indicating for the first time the use of beta-actin gene as an internal invariant control. It increased the mRNA levels of MMP-1 while almost no effect on Col-I and TIMPs was observed. CONCLUSIONS: The results indicate that PDL remodeling following application of orthodontic force could be partly attributed to the direct effect of the force on MMP-1 gene expression in fibroblasts.

Actins↗

PubMed2004

Prediction of premolar tooth lengths based on their panoramic radiographic lengths.

OBJECTIVE: Establishing a linear regression model for the determination of first premolar lengths based on panoramic radiographs. MATERIALS AND METHODS: The real lengths of 112 first premolars extracted for orthodontic reasons were measured and compared with their panoramic lengths. The teeth were divided into four groups according to their intraoral quadrant locations (T14, T24, T34, T44) and regression analysis was conducted for each group. RESULTS: A linear regression model for the prediction of tooth length (mm) based on the panoramic length was established (P < 0.0001): For group T14 the predicted length = (panoramic length x 0.698) + 2.61. For group T24 the predicted length = (panoramic length x 0.5056) + 7.844. For group T34 the predicted length = (panoramic length x 0.5075) + 9.282. For group T44 the predicted length = (panoramic length x 0.436) + 11.298. CONCLUSION: Prediction of all first premolar lengths using their panoramic images is both feasible and reliable.

Adolescent↗

PubMed2003

Osteonecrosis in a chemically induced rat model of human hemolytic disorders associated with thrombosis--a new model for avascular necrosis of bone.

Bone injury occurs in human hemolytic disorders associated with thrombosis, such as beta-thalassemia and sickle cell disease. Exposure of rats to 2-butoxyethanol (BE) has been associated with hemolytic anemia, disseminated thrombosis, and infarction in multiple organs including bone. This rat model apparently mimics acute hemolysis and thrombosis in humans. To elucidate the extent of bone injury, male and female Fischer F344 rats were given 4 daily doses of 250 mg BE/5 ml water/kg of body weight. Tail vertebrae were studied by histopathology and magnetic resonance imaging (MRI). Thrombosis and infarction were seen in both sexes, but females were more severely affected. Lesions were characterized by extensive medullary fat necrosis, granulomatous inflammation, fibroplasia, growth plate degeneration, and new woven bone formation adjacent to necrotic bone trabeculae. MRI mean and standard deviation tissue-density data for both sexes indicated a significant (P < or = 0.05) decrease following 4-days treatment and a significant increase (P < or = 0.05) following an additional 24 days without treatment. Thus, MRI was useful in revealing BE-induced bone injury, which was predominantly necrotic initially and subsequently regenerative with proliferation of connective tissue and bone following postischemia recovery.

Animals↗

PubMed2001

Basic fibroblast growth factor suppresses tropoelastin gene expression in cultured human periodontal fibroblasts.

Growth factors are known to play a major role in the regeneration of the periodontium. Basic fibroblast growth factor (bFGF) is a polypeptide growth factor considered to have a role in chemotaxis and mitogenesis of periodontal ligament (PDL) cells. The aim of this study was to assess the effect of bFGF on the transcription level of tropoelastin. As known controls, we assessed the transcription levels of collagen type I, collagen type II and the housekeeping gene, actin. Initially, PDL cells were cultured without bFGF for 3, 7 and 14 days. At each time point. total RNA was extracted and the levels of transcription were assessed by semiquantitative reverse transcription polymerase chain reaction (RT-PCR) assay. The results showed that tropoelastin mRNA is transcribed in PDL cells and its levels increased from minimal amounts by day 3 to maximal amounts by day 14 of culture. We further examined the effect of the addition of 10 ng/ml bFGF to the culture media by day 14. The results showed that the addition of bFGF suppressed the transcription level of tropoelastin. At that time, as expected, a decrease in collagen type I transcription level was shown, while the transcription level of collagen type III was not affected. The findings that elastin is transcribed in vitro by PDL cells, but only negligibly in vivo, imply mechanisms that downregulate or even shut down the expression of the elastin gene in the functioning PDL. Basic FGF might be one of the cytokines involved in control of elastin expression in vivo.

Actins↗

PubMed2001

The effect of mechanical force on mRNA levels of collagenase, collagen type I, and tissue inhibitors of metalloproteinases in gingivae of dogs.

Orthodontic force causes an injury to and subsequent degradation of the attachment apparatus, thus leading to the transposition of the tooth. The gingiva, however, is compressed and sometimes becomes hypertrophic with tooth movement and often shrinks after treatment. To study the effect of force on the gingiva, we applied orthodontic force in dogs and analyzed gingival tissues 1, 2, 3, 7, 14, and 28 days later as well as after removing the force. The effect of force on mRNA levels of collagen type I (col-I), matrix metalloproteinase-1 (MMP- 1), and tissue inhibitors 1 and 2 (TIMPs) genes was analyzed by RT-PCR, and MMP-1 activity was determined by zymography. The results showed that force significantly increased both the mRNA levels of MMP-1 and its interstitial activity. After the removal of force, MMP-1 gene expression was significantly decreased. The results could partly explain the clinically observed shrinkage and adaptation of the gingiva during tooth movement.

Adaptation, Physiological↗

PubMed2000

A new multipurpose dental adhesive for orthodontic use: an in vitro bond-strength study.

The purpose of this study was to evaluate the compatibility of a new dental adhesive, High-Q-Bond (HQB) adhesive, for the bonding of orthodontic brackets by determining its bond strength and the mode of bond failure after debonding. Eighty extracted human premolars were divided into 4 groups, 20 in each group. In groups 1 and 2, stainless steel brackets were bonded to etched enamel with HQB and Right-On adhesives respectively. In groups 3 and 4, the same adhesives were used to bond stainless-steel brackets to roughened, old amalgam restorations prepared in the teeth. After 72 hours of incubation in saline solution at 37 degrees C, debonding was performed with a shearing force. The force at bond failure was recorded, and the mode of bond failure was examined. Results showed that when bonding to enamel, both the HQB and the Right-On material achieved adequate bond strength, and no significant difference was found between the two. However, after debonding, the HQB material left no adhesive on the enamel, whereas the Right-On material left significant amounts of adhesive on the enamel. When bonding to amalgam, the HQB material had a significantly higher shear bond strength than did the Right-On adhesive. It is suggested that HQB can be applied for orthodontic use, but further clinical studies are required to evaluate its efficacy.

Dental Amalgam↗

PubMed1999

Gingival response to orthodontic force.

Orthodontic tooth movement is brought about by prolonged application of force on the attachment apparatus. This results in cellular and extracellular changes within the periodontium. As shown in numerous studies, tooth movement is achieved after the remodeling of alveolar bone and the response of the periodontal ligament to the mechanical force. Although gingival changes have also been found to be an important factor in the overall response, the effect of orthodontic tooth movement on the gingiva has been investigated to a lesser extent. Unlike bone and periodontal ligament, which regain their original structure after removal of force, the gingival tissue does not regain its pretreatment structure, a fact on which a hypothesis has been made that tooth relapse after removal of retention may be associated with changes in the gingiva. The present review summarizes available data on the effect of orthodontic force on collagen, elastin, and collagenase in the gingiva and its relevance to understanding the mechanism of tooth relapse.

Animals↗

PubMed1999

Severe high Angle Class II Division 1 malocclusion with vertical maxillary excess and gummy smile: a case report.

Severe Class II Division 1 malocclusion with vertical maxillary excess and gummy smiles can be treated in several ways. Early orthodontic treatment with vertical control may decrease the malocclusion as well as improve the appearance. In severe cases, orthognathic surgery might be the optimal solution. The following case report describes a patient with a severe gummy smile, where the final esthetic improvement was achieved by using a periodontal procedure after orthodontic treatment.

Cephalometry↗

PubMed1999

Immediate placement of implants in extraction sites of maxillary impacted canines.

BACKGROUND: Treatment of asymptomatic impacted maxillary canines in adults is inevitable when primary canine becomes lost through extraction or exfoliation or when the impacted tooth becomes symptomatic. Treatment alternatives include an orthodontic procedure to bring the unerupted tooth to the dental arch or prosthetic replacement of the missing tooth. The authors describe an alternative treatment that involves immediate placement of implants into extraction sockets of the teeth. CASE DESCRIPTION: A patient with bilateral palatally impacted upper canines chose to have the unerupted teeth removed and replaced with implants and crowns. Two hydroxyapatite cylindrical implants were inserted through the alveolar ridge into the extraction sites. The unfilled areas in the extraction sites, around the dental implants, were packed and covered with demineralized freeze-dried bone allograft in conjunction with a collagen membrane barrier. Six months after implantation, computed tomography revealed complete osseous fill of the extraction defects and no bone loss around the implants. The implants were uncovered, and porcelain-fused-to-metal restorations were fabricated and placed. CLINICAL IMPLICATIONS: This treatment modality avoids the need for conventional preparation of teeth as part of prosthetic reconstruction or prolonged orthodontic treatment aimed at bringing the impacted canine to the dental arch. Combining the implantation with bone augmentation preserved the alveolar bone and shortened the treatment period.

Bone Transplantation↗

PubMed1998

The effect of centrifugal force on the transcription levels of collagen type I and collagenase in cultured canine gingival fibroblasts.

An orthodontically treated tooth is often destabilized in its newly corrected location and relapses towards its original position. Hitherto, the explanation for this phenomenon was that orthodontic force brings about "stretching" of gingival collagen fiber, which "pull back" the tooth towards its pretreatment position. A previous ultrastructural study showed that after force application the gingival collagen fibres were torn, laterally spaced and of increased diameter. Therefore, they could not "pull back" the tooth and be the cause of the relapse. In the present study, in order to find a more plausible explanation at the molecular level, the effect of pressure on the gene transcription of collagen type I and tissue collagenase was examined by semiquantitative, reverse transcriptase-polymerase chain reaction assay. Attached buccal gingiva was excised from anaesthetized dogs and gingival fibroblasts were grown in culture. Following application of pressure (0.167 kg/l g cell mass), the transcription of collagen type I was increased while that of tissue collagenase was decreased. These results corroborate the ultrastructural in vivo findings that orthodontic force is associated with larger amounts of collagen type I in the gingiva.

Animals↗

PubMed1998

The effect of different porcelain conditioning techniques on shear bond strength of stainless steel brackets.

With the increasing demand for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. Optimal adhesion to a porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding. In this study, 90 glazed porcelain facets were divided into three groups according to different conditioning techniques: (1) roughening with a coarse diamond; (2) hydrofluoric acid 8%; (3) microetching with 60 micron aluminum oxide particles. Each group was divided into three groups and stainless steel brackets were then bonded to the conditioned porcelain with three different dental adhesives. The adhesives used were: (1) silane+Right-On; (2) silane+Concise; (3) High-Q-Bond without silane. Four additional facets (three of which conditioned as above and one intact) were analyzed macroscopically and by scanning electron microscopy. Shear bond strength was measured with an Instron universal testing machine and a macroscopic examination of the debonded porcelain surfaces was performed. Results showed that shear bond strength was highly influenced by both conditioning technique and the adhesive. Shear bond strength of the High-Q-Bond groups was significantly lower than both the silane+Right-On and the silane+Concise groups; nevertheless the shear bond strength achieved by High-Q-Bond was enough to sustain full orthodontic treatment duration (except for the group conditioned by roughening with a coarse diamond). Scanning electronic microscopy analysis revealed that diamond roughening and microetching produced only a surface-peeling pattern, whereas hydrofluoric acid conditioning produced an extensive in-depth penetrating pattern. Hydrofluoric acid preparation produced greater shear bond strength than both diamond roughening and microetching. After debonding by means of a shearing force, the percentage of damaged porcelain surfaces in the silane+Concise groups was significantly higher than the silane+Right-On and High-Q-Bond groups.

Acid Etching, Dental↗

PubMed1998

Exogenous non-crosslinked collagen enhances granulation tissue formation in dermal excision wounds in guinea pigs.

Based on previous observations indicating a role for collagen peptides in eliciting a positive feedback for collagen biosynthesis, this study was initiated to elucidate the effect of non-crosslinked collagen on granulation tissue formation in dermal excision wounds. The wounds were treated with either non-crosslinked or crosslinked native collagen, or left untreated as controls. Granulation tissue was analyzed for collagen type I mRNA, for levels of interstitial collagen and for the number of blood vessels. The results indicated significant increases in procollagen type I mRNA, in interstitial collagen, in the number of blood vessels and in epithelial advance in the non-crosslinked collagen-treated wounds relative to the untreated controls. It is assumed that the presence of non-crosslinked collagen in a healing wound enhances both procollagen type I biosynthesis and the repair process of dermal wounds, due to the more readily released collagen peptides derived from this exogenous collagen dressing.

Animals↗

PubMed1997

Lack of influence of cyclosporin A on levels of gingival procollagen types I and III mRNAs in rats of different ages.

Previous studies showed that gingival overgrowth following cyclosporin A (CsA) administration is not associated with an increase in interstitial collagen. It also was shown that CsA causes a significant decrease in collagen content within the gingival stroma. In order to determine whether this decrease is caused by down-regulation of collagen mRNA, the procollagen mRNA level in gingiva of young and old rats was measured correlated with the ratio of interstitial collagen to DNA in these regions. Hybridization of 32P-labelled cDNA probes for procollagen types I and III with total RNA extracted from the molar gingiva showed that administration of Csa did not change the steady-state levels of mRNAs for both procollagens in the gingiva of either young or old rats. The ratio of gingival interstitial collagen to DNA was significantly reduced in the CsA-treated animals (4.2 +/- 0.85) relative to the controls (7.8 +/- 1.6). It is concluded that the reduction in interstitial collagen following CsA treatment is not age-related, and is most probably caused by increased degradation rather by decreased biosynthesis.

Age Factors↗

PubMed1997

Orthodontic-prosthetic treatment to replace maxillary incisors exfoliated because of improper use of orthodontic elastics: a case report.

This article describes the iatrogenic exfoliation of maxillary central incisors following the improper use of orthodontic elastic bands. The unsecured rubber band had migrated apically and caused an almost "bloodless extraction" of both maxillary central incisors. A combined orthodontic-prosthetic solution was used to replace the lost incisors.

Adolescent↗

PubMed1996

Gingival response to a new multipurpose dental adhesive: a histologic study in dogs.

The biocompatibility of cementing materials is a prerequisite for any dental procedure. In this study, the tolerance of gingival tissue to an advanced fourth-generation dental adhesive (High-Q-Bond) was tested in dogs. The results from High-Q-Bond adhesive were compared with those obtained from Superbond C&B adhesive. Buccal class V subgingival cavities were restored with either High-Q-Bond or Superbond C&B adhesive Untreated teeth served as normal intact controls. The teeth with the attached buccal gingivae were extracted and processed for histologic examination. The histologic observations showed an inflammatory response in the gingiva of the Superbond C&B adhesive-treated teeth, whereas the High-Q-Bond fillings exhibited no noticeable adverse effect on the gingival tissue.

Animals↗